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Thyroid cancer more commonly affects women than men and is the third most frequently diagnosed cancer among women of reproductive age. We conducted a nested case-control study within the Finnish Maternity Cohort to evaluate pre-diagnostic sex steroid and thyroid function markers in relation to subsequent maternal papillary thyroid cancer. Cases (n = 605) were women ages 18-44 years, who provided an early-pregnancy (<20 weeks gestation) blood sample and were diagnosed with papillary thyroid cancer up to 11 years afterward. Controls (n = 1185) were matched to cases 2:1 by gestational age, mother's age, and date at blood draw. Odds ratios (ORs) for the associations of serum thyroid peroxidase antibodies (TPO-Ab), thyroglobulin antibodies (Tg-Ab), thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), progesterone, and estradiol with papillary thyroid cancer were estimated using conditional logistic regression. TPO-Ab and Tg-Ab positivity (>95th percentile among controls) were associated with more than 3-fold (OR = 3.32, 95% confidence interval [CI] 2.33-4.72) and 2-fold (OR = 2.03, 95% CI 1.41-2.93) increased odds of papillary thyroid cancer, respectively. These associations were similar by time since blood draw, parity, gestational age, smoking status, and age and stage at diagnosis. In models excluding TPO-Ab or Tg-Ab positivity, TPO-Ab (quartile 4 vs. 1: OR = 1.66, 95% CI 1.17-2.37, p-trend = .002) and Tg-Ab (quartile 4 vs. 1: OR = 1.74, 95% CI 1.22-2.49, p-trend = .01) levels were positively associated with papillary thyroid cancer. No associations were observed for estradiol, progesterone, TSH, fT3, or fT4 overall. Our results suggest that thyroid autoimmunity in early pregnancy may increase the risk of maternal papillary thyroid cancer., (© 2024 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Background: Ultraviolet radiation (UVR) exposure is the primary risk factor for melanoma although the relationship is complex. Compared to radiation from UVB wavelengths, UVA makes up a majority of the surface solar UVR, penetrates the skin more deeply, is the principal range emitted by tanning beds, and is less filtered by sunscreens and window glass. Few studies have examined the relationship between ambient UVA and UVB and melanoma risk., Methods: Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were estimated for the association between satellite-based ambient (based on residential history) UVA, UVB and melanoma in non-Hispanic White participants using data from the United States Radiologic Technologists study, a large, nationwide prospective cohort. Associations of UVA and UVB quartile (Q) were examined in mutually adjusted and stratified models, additionally adjusted for demographic and sun sensitivity characteristics., Results: There were 837 incident melanoma cases among 62,785 participants. Incidence of melanoma was statistically significantly increased for the highest quartile of childhood UVA exposure after adjustment for UVB (IRR = 2.82; 95%CI:1.46,5.44), but not for higher childhood UVB after adjustment for UVA. Childhood UVA was associated with increased melanoma risk within strata of UVB. Childhood UVB was not associated with melanoma after adjustment for UVA, but there was some evidence of lower risk with increased lifetime ambient UVB after UVA adjustment., Conclusions: Melanoma risk was elevated among participants living in locations with high annual childhood and lifetime UVA after controlling for UVB. With confirmation, these findings support increased protection from solar UVA for melanoma prevention., (Published by Oxford University Press 2024.)

Purpose: To summarize dose trends from 1980 to 2020 for 19,651 U.S. Radiologic Technologists who reported assisting with fluoroscopically guided interventional procedures (FGIPs), overall and by work history characteristics., Materials and Methods: A total of 762,310 annual personal dose equivalents at a 10-mm reference depth (doses) during 1980-2020 for 43,823 participants of the U.S. Radiologic Technologists (USRT) cohort who responded to work history questionnaires administered during 2012-2014 were summarized. This population included 19,651 technologists who reported assisting with FGIP (≥1 time per month for ≥12 consecutive months) at any time during the study period. Doses corresponding to assistance with FGIP were estimated in terms of proximity to patients, monthly procedure frequency, and procedure type. Box plots and summary statistics (eg, medians and percentiles) were used to describe annual doses and dose trends., Results: Median annual dose corresponding to assistance with FGIP was 0.65 mSv (interquartile range [IQR], 0.60-1.40 mSv; 95th percentile, 6.80). Higher occupational doses with wider variability were associated with close proximity to patients during assistance with FGIP (median, 1.20 mSv [IQR, 0.60-4.18 mSv]; 95th percentile, 12.66), performing ≥20 FGIPs per month (median, 0.75 mSv [IQR, 0.60-2.40 mSv]; 95th percentile, 9.44), and assisting with high-dose FGIP (median, 0.70 mSv [IQR, 0.60-1.90 mSv]; 95th percentile, 8.30)., Conclusions: Occupational doses corresponding to assistance with FGIP were generally low but varied with exposure frequency, procedure type, and proximity to patients. These results highlight the need for vigilant dose monitoring, radiation safety training, and proper protective equipment., (Published by Elsevier Inc.)

Background: Expansion of genome-wide association studies across population groups is needed to improve our understanding of shared and unique genetic contributions to breast cancer. We performed association and replication studies guided by a priori linkage findings from African ancestry (AA) relative pairs., Methods: We performed fixed-effect inverse-variance weighted meta-analysis under three significant AA breast cancer linkage peaks (3q26-27, 12q22-23, and 16q21-22) in 9241 AA cases and 10 193 AA controls. We examined associations with overall breast cancer as well as estrogen receptor (ER)-positive and negative subtypes (193,132 SNPs). We replicated associations in the African-ancestry Breast Cancer Genetic Consortium (AABCG)., Results: In AA women, we identified two associations on chr12q for overall breast cancer (rs1420647, OR = 1.15, p = 2.50×10-6; rs12322371, OR = 1.14, p = 3.15×10-6), and one for ER-negative breast cancer (rs77006600, OR = 1.67, p = 3.51×10-6). On chr3, we identified two associations with ER-negative disease (rs184090918, OR = 3.70, p = 1.23×10-5; rs76959804, OR = 3.57, p = 1.77×10-5) and on chr16q we identified an association with ER-negative disease (rs34147411, OR = 1.62, p = 8.82×10-6). In the replication study, the chr3 associations were significant and effect sizes were larger (rs184090918, OR: 6.66, 95% CI: 1.43, 31.01; rs76959804, OR: 5.24, 95% CI: 1.70, 16.16)., Conclusion: The two chr3 SNPs are upstream to open chromatin ENSR00000710716, a regulatory feature that is actively regulated in mammary tissues, providing evidence that variants in this chr3 region may have a regulatory role in our target organ. Our study provides support for breast cancer variant discovery using prioritization based on linkage evidence., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: A high body mass index (BMI, kg/m 2 ) is associated with decreased risk of breast cancer before menopause, but increased risk after menopause. Exactly when this reversal occurs in relation to menopause is unclear. Locating that change point could provide insight into the role of adiposity in breast cancer etiology., Methods: We examined the association between BMI and breast cancer risk in the Premenopausal Breast Cancer Collaborative Group, from age 45 up to breast cancer diagnosis, loss to follow-up, death, or age 55, whichever came first. Analyses included 609,880 women in 16 prospective studies, including 9956 who developed breast cancer before age 55. We fitted three BMI hazard ratio (HR) models over age-time: constant, linear, or nonlinear (via splines), applying piecewise exponential additive mixed models, with age as the primary time scale. We divided person-time into four strata: premenopause; postmenopause due to natural menopause; postmenopause because of interventional loss of ovarian function (bilateral oophorectomy (BO) or chemotherapy); postmenopause due to hysterectomy without BO. Sensitivity analyses included stratifying by BMI in young adulthood, or excluding women using menopausal hormone therapy., Results: The constant BMI HR model provided the best fit for all four menopausal status groups. Under this model, the estimated association between a five-unit increment in BMI and breast cancer risk was HR=0.87 (95% CI: 0.85, 0.89) before menopause, HR=1.00 (95% CI: 0.96, 1.04) after natural menopause, HR=0.99 (95% CI: 0.93, 1.05) after interventional loss of ovarian function, and HR=0.88 (95% CI: 0.76, 1.02) after hysterectomy without BO., Conclusion: The BMI breast cancer HRs remained less than or near one during the 45-55 year age range indicating that the transition to a positive association between BMI and risk occurs after age 55., Competing Interests: Declaration of Competing Interest none., (Published by Elsevier Ltd.)

Human exposure to per- and polyfluoroalkyl substances (PFAS) occurs globally through contaminated food, dust, and drinking water. Studies of PFAS and thyroid cancer have been limited. We conducted a nested case-control study of prediagnostic serum levels of 19 PFAS and papillary thyroid cancer (400 cases, 400 controls) in the Finnish Maternity Cohort (pregnancies 1986-2010; follow-up through 2016), individually matched on sample year and age. We used conditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for log 2 transformed and categorical exposures, overall and stratified by calendar period, birth cohort, and median age at diagnosis. We adjusted for other PFAS with Spearman correlation rho = 0.3-0.6. Seven PFAS, including perfluoroctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), N-ethyl-perfluorooctane sulfonamidoacetic acid (EtFOSAA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluorohexane sulfonic acid (PFHxS) were detected in >50% of women. These PFAS were not associated with risk of thyroid cancer, except for PFHxS, which was inversely associated (OR log 2  = 0.82, 95% CI: 0.70-0.97). We observed suggestive but imprecise increased risks associated with PFOA, PFOS, and EtFOSAA for those diagnosed at ages <40 years, whereas associations were null or inverse among those diagnosed at 40+ years (P-interaction: .02, .08, .13, respectively). There was little evidence of other interactions. These results show no clear association between PFAS and papillary thyroid cancer risk. Future work would benefit from evaluation of these relationships among those with higher exposure levels and during periods of early development when the thyroid gland may be more susceptible to environmental harms., (© 2023 UICC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Purpose: There is strong evidence that leisure-time physical activity is protective against postmenopausal breast cancer risk but the association with premenopausal breast cancer is less clear. The purpose of this study was to examine the association of physical activity with the risk of developing premenopausal breast cancer., Methods: We pooled individual-level data on self-reported leisure-time physical activity across 19 cohort studies comprising 547,601 premenopausal women, with 10,231 incident cases of breast cancer. Multivariable Cox regression was used to estimate hazard ratios (HRs) and 95% CIs for associations of leisure-time physical activity with breast cancer incidence. HRs for high versus low levels of activity were based on a comparison of risk at the 90th versus 10th percentiles of activity. We assessed the linearity of the relationship and examined subtype-specific associations and effect modification across strata of breast cancer risk factors, including adiposity., Results: Over a median 11.5 years of follow-up (IQR, 8.0-16.1 years), high versus low levels of leisure-time physical activity were associated with a 6% (HR, 0.94 [95% CI, 0.89 to 0.99]) and a 10% (HR, 0.90 [95% CI, 0.85 to 0.95]) reduction in breast cancer risk, before and after adjustment for BMI, respectively. Tests of nonlinearity suggested an approximately linear relationship ( P nonlinearity = .94). The inverse association was particularly strong for human epidermal growth factor receptor 2-enriched breast cancer (HR, 0.57 [95% CI, 0.39 to 0.84]; P het = .07). Associations did not vary significantly across strata of breast cancer risk factors, including subgroups of adiposity., Conclusion: This large, pooled analysis of cohort studies adds to evidence that engagement in higher levels of leisure-time physical activity may lead to reduced premenopausal breast cancer risk.

The escalating incidence of differentiated thyroid cancer (DTC) in pediatric patients and the resultant growing use of radioactive iodine (RAI) reinforce the need to evaluate radiation exposure to normal tissues and radiation-induced health risks in pediatric patients undergoing RAI therapy. In the current study, we calculated absorbed dose coefficients (i.e. absorbed dose per unit activity administered, mGy MBq -1 ) specific for pediatric patients with localized DTC undergoing RAI therapy following total thyroidectomy for use in epidemiological studies. We first modified previously-published biokinetic models for adult thyroid cancer patients to achieve a reasonable agreement with iodine biokinetics observed in pediatric patients or design principles addressed in the International Commission on Radiological Protection (ICRP) reference age-specific biokinetic models. We then combined the biokinetic models in conjunction with S values derived from ICRP reference pediatric voxel phantoms. The absorbed dose coefficients for pediatric patients were overall greater than those for adults with a ratio (pediatric/adult) up to 11.6 and rapidly decreased with increasing age. The sensitivity analysis showed that the renal clearance rate and S values may have the greatest impact on the absorbed dose coefficients with the rank correlation coefficients ranging from -0.53 to -0.82 (negative correlations) and from 0.51 to 0.80 (positive correlations), respectively. The results of the current study may be utilized in clinical or epidemiological studies to estimate organ-specific radiation absorbed doses and radiation-associated health risks among pediatric thyroid cancer patients., (© 2024 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved.)

Background: The incidence of differentiated thyroid cancer (DTC) is higher in women than in men but whether sex steroid hormones contribute to this difference remains unclear. Studies of reproductive and hormonal factors and thyroid cancer risk have provided inconsistent results., Methods: Original data from 1 252 907 women in 16 cohorts in North America, Europe, Australia and Asia were combined to evaluate associations of DTC risk with reproductive and hormonal factors. Multivariable-adjusted Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% CIs., Results: During follow-up, 2142 women were diagnosed with DTC. Factors associated with higher risk of DTC included younger age at menarche (<10 vs 10-11 years; HR, 1.28; 95% CI, 1.00-1.64), younger (<40; HR, 1.31; 95% CI, 1.05-1.62) and older (≥55; HR, 1.33; 95% CI, 1.05-1.68) ages at menopause (vs 40-44 years), ever use of menopausal hormone therapy (HR, 1.16; 95% CI, 1.02-1.33) and previous hysterectomy (HR, 1.25; 95% CI, 1.13-1.39) or bilateral oophorectomy (HR, 1.14; 95% CI, 1.00-1.29). Factors associated with lower risk included longer-term use (≥5 vs <5 years) of oral contraceptives (HR, 0.86; 95% CI, 0.76-0.96) among those who ever used oral contraception and baseline post-menopausal status (HR, 0.82; 95% CI, 0.70-0.96). No associations were observed for parity, duration of menopausal hormone therapy use or lifetime number of reproductive years or ovulatory cycles., Conclusions: Our study provides some evidence linking reproductive and hormonal factors with risk of DTC. Results should be interpreted cautiously considering the modest strength of the associations and potential for exposure misclassification and detection bias. Prospective studies of pre-diagnostic circulating sex steroid hormone measurements and DTC risk may provide additional insight., (© The Author(s) 2023; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.)

Background: Despite the excellent disease-specific survival associated with low-risk differentiated thyroid cancer (DTC), its diagnosis and management have been linked to patient concerns about cancer recurrence, treatment-related health risks, and mortality. Lack of information regarding long-term health outcomes can perpetuate these concerns. Therefore, we assessed all-cause and cause-specific mortality in a large cohort of individuals diagnosed with low-risk DTC. Methods: From the U.S. Surveillance, Epidemiology, and End Results-12 cancer registry database (1992-2019), we identified 51,854 individuals (81.8% female) diagnosed with first primary DTC at low risk of recurrence (≤4 cm, localized). We estimated cause-specific cumulative mortality by time since diagnosis, accounting for competing risks. Standardized mortality ratios (SMRs) and CIs were used to compare observed mortality rates in DTC patients with expected rates in the matched U.S. general population, overall and by time since DTC diagnosis. We used Cox proportional hazards models to examine associations between radioactive iodine (RAI) treatment and cause-specific mortality. Results: During follow-up (median = 8.8, range 0-28 years), 3467 (6.7%) deaths were recorded. Thyroid cancer accounted for only 4.3% of deaths ( n  = 148). The most common causes of death were malignancies (other than thyroid cancer) ( n  = 1031, 29.7%) and cardiovascular disease (CVD; n  = 912, 26.3%). The 20-year cumulative mortality rate from thyroid cancer, malignancies (other than thyroid or nonmelanoma skin cancer), and CVD was 0.6%, 4.6%, and 3.9%, respectively. Lower than expected mortality was observed for all causes excluding thyroid cancer (SMR = 0.69 [CI 0.67-0.71]) and most specific causes, including all malignancies combined (other than thyroid cancer; SMR = 0.80 [CI 0.75-0.85]) and CVD (SMR = 0.64 [CI 0.60-0.69]). However, mortality rates were elevated for specific cancers, including pancreas (SMR = 1.58 [CI 1.18-2.06]), kidney and renal pelvis (SMR = 1.85 [CI 1.10-2.93]), and brain and other nervous system (SMR = 1.62 [CI 0.99-2.51]), and myeloma (SMR = 2.35 [CI 1.46-3.60]) and leukemia (SMR = 1.62 [CI 1.07-2.36]); these associations were stronger ≥10 years after diagnosis. RAI was not associated with risk of cause-specific death, but numbers of events were small and the range of administered activities was likely narrow. Conclusions: Overall, our findings provide reassurance regarding low overall and cause-specific mortality rates in individuals with low-risk DTC. Additional research is necessary to confirm and understand the increased mortality from certain subsequent cancers.

Background: Most patients diagnosed with thyroid cancer have low-risk disease, but some have a higher risk for persistent or recurrent disease and even death from thyroid cancer. Few studies have evaluated potential anthropometric, lifestyle, or dietary risk factors for advanced or aggressive types of thyroid cancer., Methods: Using data from a large US cohort study, we examined associations for high-risk thyroid cancer (HRTC) and, separately, low-risk thyroid cancer (LRTC) in relation to anthropometric factors, diet, smoking, and alcohol consumption. The National Institutes of Health-American Association of Retired Persons (NIH-AARP) Diet and Health Study included 304,122 participants (124,656 women and 179,466 men) without a history of cancer who completed a mailed questionnaire in 1996-1997 and were followed for cancer incidence through 2011 via linkages with state cancer registries. Hazard ratios (HRs) for anthropometric, dietary, and lifestyle factors in relation to HRTC or LRTC, defined using guidance from the American Thyroid Association initial risk of recurrence classification, were calculated using multivariable-adjusted Cox proportional hazards regression models., Results: During follow-up (median = 10.1 years), 426 participants were diagnosed with HRTC (n = 95) or LRTC (n = 331). In models combining men and women, baseline waist circumference (per 5 cm, HR = 1.13, 95% confidence interval [CI] 1.01-1.27) and weight gain from age 18 years to baseline age (per 5 kg, HR = 1.14, 95% CI 1.02-1.28) were positively associated with risk of HRTC but not LRTC. In contrast, vegetable intake (per cup equivalents/day, HR = 1.15, 95% CI 1.01-1.30), cigarette smoking (current vs. never, HR = 0.39, 95% CI 0.23-0.68), and alcohol consumption (per drink/day, HR = 0.83, 95% CI 0.70-0.97) were associated with risk of LRTC but not HRTC. The association of LRTC risk with vegetable intake was limited to men, and that of current smoking was more pronounced in women., Conclusions: Our findings suggest that greater waist circumference and adulthood weight gain are associated with thyroid cancers at higher risk for recurrence. These results may have implications for the primary prevention of advanced thyroid cancer., (© 2023 John Wiley & Sons Ltd.)

Background: Genome-wide studies of gene-environment interactions (G×E) may identify variants associated with disease risk in conjunction with lifestyle/environmental exposures. We conducted a genome-wide G×E analysis of ~ 7.6 million common variants and seven lifestyle/environmental risk factors for breast cancer risk overall and for estrogen receptor positive (ER +) breast cancer., Methods: Analyses were conducted using 72,285 breast cancer cases and 80,354 controls of European ancestry from the Breast Cancer Association Consortium. Gene-environment interactions were evaluated using standard unconditional logistic regression models and likelihood ratio tests for breast cancer risk overall and for ER + breast cancer. Bayesian False Discovery Probability was employed to assess the noteworthiness of each SNP-risk factor pairs., Results: Assuming a 1 × 10 -5 prior probability of a true association for each SNP-risk factor pairs and a Bayesian False Discovery Probability < 15%, we identified two independent SNP-risk factor pairs: rs80018847(9p13)-LINGO2 and adult height in association with overall breast cancer risk (OR int  = 0.94, 95% CI 0.92-0.96), and rs4770552(13q12)-SPATA13 and age at menarche for ER + breast cancer risk (OR int  = 0.91, 95% CI 0.88-0.94)., Conclusions: Overall, the contribution of G×E interactions to the heritability of breast cancer is very small. At the population level, multiplicative G×E interactions do not make an important contribution to risk prediction in breast cancer., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Background: Genomic regions identified by genome-wide association studies (GWAS) for bladder cancer risk provide new insights into etiology., Objective: To identify new susceptibility variants for bladder cancer in a meta-analysis of new and existing genome-wide genotype data., Design, Setting, and Participants: Data from 32 studies that includes 13,790 bladder cancer cases and 343,502 controls of European ancestry were used for meta-analysis., Outcome Measurements and Statistical Analyses: Log-additive associations of genetic variants were assessed using logistic regression models. A fixed-effects model was used for meta-analysis of the results. Stratified analyses were conducted to evaluate effect modification by sex and smoking status. A polygenic risk score (PRS) was generated on the basis of known and novel susceptibility variants and tested for interaction with smoking., Results and Limitations: Multiple novel bladder cancer susceptibility loci (6p.22.3, 7q36.3, 8q21.13, 9p21.3, 10q22.1, 19q13.33) as well as improved signals in three known regions (4p16.3, 5p15.33, 11p15.5) were identified, bringing the number of independent markers at genome-wide significance (p < 5 × 10 -8 ) to 24. The 4p16.3 (FGFR3/TACC3) locus was associated with a stronger risk for women than for men (p-interaction = 0.002). Bladder cancer risk was increased by interactions between smoking status and genetic variants at 8p22 (NAT2; multiplicative p value for interaction [p M-I ] = 0.004), 8q21.13 (PAG1; p M-I  = 0.01), and 9p21.3 (LOC107987026/MTAP/CDKN2A; p M-I  = 0.02). The PRS based on the 24 independent GWAS markers (odds ratio per standard deviation increase 1.49, 95% confidence interval 1.44-1.53), which also showed comparable results in two prospective cohorts (UK Biobank, PLCO trial), revealed an approximately fourfold difference in the lifetime risk of bladder cancer according to the PRS (e.g., 1st vs 10th decile) for both smokers and nonsmokers., Conclusions: We report novel loci associated with risk of bladder cancer that provide clues to its biological underpinnings. Using 24 independent markers, we constructed a PRS to stratify lifetime risk. The PRS combined with smoking history, and other established risk factors, has the potential to inform future screening efforts for bladder cancer., Patient Summary: We identified new genetic markers that provide biological insights into the genetic causes of bladder cancer. These genetic risk factors combined with lifestyle risk factors, such as smoking, may inform future preventive and screening strategies for bladder cancer., (Published by Elsevier B.V.)

In the United States, renal cell carcinoma (RCC) incidence and the prevalence of obesity, an established risk factor for RCC, have been increasing for several decades. RCC is more common among older individuals. We sought to quantify the contribution of excess adiposity to the rising incidence of RCC among individuals 60 years or older. National Institutes of Health-American Association of Retired Persons Diet and Health Study data (n = 453 859 participants, enrolled in 1995-1996, age at enrollment 50-71 years) were used to estimate multivariable-adjusted hazard ratios (HRs) for RCC across body mass index categories and HRs associated with smoking. Population attributable fractions (PAFs) were calculated using estimated HRs and annual overweight/obesity prevalence from the National Health Interview Survey (1985-2008). PAF estimates were combined with RCC incidence from Surveillance, Epidemiology and End Results-13 to calculate annual percent changes in RCC incidence attributable (and unrelated) to overweight/obesity. We found that between 1995 and 2018, among individuals aged 60 years and older, PAF for overweight/obesity increased from 18% to 29% for all RCCs. In comparison, the PAF for smoking declined from 12% to 9%. RCC incidence increased 1.8% per year (95% confidence interval [CI] 1.5%-2.1%) overall, while RCC incidence attributable to overweight/obesity increased 3.8% per year (95%CI 3.5%-4.2%) and RCC incidence unrelated to overweight/obesity increased 1.2% per year (95% CI 0.9%-1.4%). In conclusion, overweight/obesity appears to have contributed importantly to the rising incidence of RCC in the United States since the mid-1990s. Public health interventions focused on reducing overweight and obesity could help substantially in curbing this trend., (Published 2023. This article is a U.S. Government work and is in the public domain in the USA.)

Background: Thyroid cancer incidence has increased worldwide. Obesity trends may play a role, but the underlying biological pathways are not well-characterized. Therefore, we examined associations of excess adiposity and obesity-related metabolic conditions with thyroid cancer incidence., Methods: From the Sister Study, a cohort of sisters of women with breast cancer, we included 47,739 women who were cancer-free at baseline (2003-2009). Height, weight, waist and hip circumference, and blood pressure were measured at baseline and medical history was self-reported. Cox proportional hazards regression models were adjusted for age (time scale), race/ethnicity, smoking, baseline history of benign thyroid disease, and frequency of routine healthcare visits., Findings: During follow-up (median = 12.5; max = 15.9 years), 259 women reported incident thyroid cancer. Body mass index (BMI) (hazard ratio [HR] per-5 kg/m 2  = 1.25, 95% CI = 1.14-1.37), waist circumference (HR per-5 cm increase  = 1.11, 95% CI = 1.06-1.15), and waist-to-hip ratio (HR  ≥0.85-versus-<0.85  = 1.49, 95% CI = 1.14-1.94) were positively associated with thyroid cancer incidence, as were metabolic syndrome (HR = 1.67, 95% CI = 1.24-2.25), dyslipidemia (HR = 1.46, 95% CI = 1.13-1.90), borderline diabetes (HR = 2.06, 95% CI = 1.15-3.69), hypertension (HR = 1.49, 95% CI = 1.12-1.96), and polycystic ovary syndrome (PCOS, HR = 2.10, 95% CI = 1.20-3.67). These associations were attenuated with additional BMI adjustment, although dyslipidemia (HR = 1.35, 95% CI = 1.04-1.75) and PCOS (HR = 1.86, 95% CI = 1.06-3.28) remained associated with thyroid cancer incidence. Hypothyroidism was not associated with thyroid cancer., Interpretation: In this cohort of sisters of women diagnosed with breast cancer, excess adiposity and several obesity-related metabolic conditions were associated with thyroid cancer incidence. These findings provide insights into potential biological mechanisms linking obesity and thyroid cancer., Funding: This research was supported by the Intramural Research Program of the National Institutes of Health, National Cancer Institute and National Institute of Environmental Health Sciences (Z01-ES044005)., Competing Interests: All authors declare no conflict of interest.

Use of radioactive iodine (RAI) for thyroid cancer patients is accompanied by elevated risks of radiation-induced adverse effects due to significant radiation exposure of normal tissues or organs other than the thyroid. The health risk estimation for thyroid cancer patients should thus be preceded by estimating normal tissue doses. Although organ dose estimation for a large cohort often relies on absorbed dose coefficients (i.e. absorbed dose per unit activity administered, mGy MBq -1 ) based on population models, no data are available for thyroid cancer patients. In the current study, we calculated absorbed dose coefficients specific for adult thyroid cancer patients undergoing RAI treatment after recombinant human TSH (rhTSH) administration or thyroid hormone withdrawal (THW). We first adjusted the transfer rates in the biokinetic model previously developed for THW patients for use in rhTSH patients. We then implemented the biokinetic models for thyroid cancer patients coupled with S values from the International Commission on Radiological Protection (ICRP) reference voxel phantoms to calculate absorbed dose coefficients. The biokinetic model for rhTSH patients predicted the extrathyroidal iodine decreasing noticeably faster than in the model for THW patients (calculated half-times of 12 and 15 h for rhTSH administration and THW, respectively). All dose coefficients for rhTSH patients were lower than those for THW patients with the ratio (rhTSH administration/THW) ranging from 0.60 to 0.95 (mean = 0.67). The ratio of the absorbed dose coefficients in the current study to the ICRP dose coefficients, which were derived from models for normal subjects, varied widely from 0.21 to 7.19, stressing the importance of using the dose coefficients for thyroid cancer patients. The results of this study will provide medical physicists and dosimetrists with scientific evidence to protect patients from excess exposure or to assess radiation-induced health risks caused by RAI treatment., (© 2023 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved.)

Background . It is critical to monitor the radiation dose delivered to patients undergoing radiography and fluoroscopy to prevent both acute and potential long-term adverse health effects. Accurate estimation of organ doses is essential to ensuring that radiation dose is maintained As Low As Reasonably Achievable. We developed a graphical user interface-based organ dose calculation tool for pediatric and adult patients undergoing radiography and fluoroscopy examinations. Methods . Our dose calculator follows the four sequential steps. First, the calculator obtains input parameters related to patient age and gender, and x-ray source data. Second, the program creates an input file describing the anatomy and material composition of a phantom, x-ray source, and organ dose scorers for Monte Carlo radiation transport using the user input parameters. Third, a built-in Geant4 module was developed to import the input file and to calculate organ absorbed doses and skeletal fluences through Monte Carlo radiation transport. Lastly, active marrow and endosteum doses are derived from the skeletal fluences and effective dose is calculated from the organ and tissue doses. Following benchmarking with MCNP6, we conducted some benchmarking calculations calculated organ doses for an illustrative cardeiac interventional fluoroscopy and compared the results with those from an existing dose calculator, PCXMC. Results . The graphical user interface-based program was entitled National Cancer Institute dosimetry system for Radiography and Fluoroscopy (NCIRF). Organ doses calculated from NCIRF showed an excellent agreement with those from MCNP6 in the simulation of an illustrative fluoroscopy exam. In the cardiac interventional fluoroscopy exam of the adult male and female phantoms, the lungs received relatively greater doses than any other organs. PCXMC based on stylistic phantoms overall overestimated major organ doses calculated from NCIRF by up to 3.7-fold (active bone marrow). Conclusion . We developed an organ dose calculation tool for pediatric and adult patients undergoing radiography and fluoroscopy examinations. NCIRF could substantially increase the accuracy and efficiency of organ dose estimation in radiography and fluoroscopy exams., (© 2023 IOP Publishing Ltd.)

Purpose: The physical properties of protons lower doses to surrounding normal tissues compared with photons, potentially reducing acute and long-term adverse effects, including subsequent cancers. The magnitude of benefit is uncertain, however, and currently based largely on modeling studies. Despite the paucity of directly comparative data, the number of proton centers and patients are expanding exponentially. Direct studies of the potential risks and benefits are needed in children, who have the highest risk of radiation-related subsequent cancers. The Pediatric Proton and Photon Therapy Comparison Cohort aims to meet this need., Methods and Materials: We are developing a record-linkage cohort of 10,000 proton and 10,000 photon therapy patients treated from 2007 to 2022 in the United States and Canada for pediatric central nervous system tumors, sarcomas, Hodgkin lymphoma, or neuroblastoma, the pediatric tumors most frequently treated with protons. Exposure assessment will be based on state-of-the-art dosimetry facilitated by collection of electronic radiation records for all eligible patients. Subsequent cancers and mortality will be ascertained by linkage to state and provincial cancer registries in the United States and Canada, respectively. The primary analysis will examine subsequent cancer risk after proton therapy compared with photon therapy, adjusting for potential confounders and accounting for competing risks., Results: For the primary aim comparing overall subsequent cancer rates between proton and photon therapy, we estimated that with 10,000 patients in each treatment group there would be 80% power to detect a relative risk of 0.8 assuming a cumulative incidence of subsequent cancers of 2.5% by 15 years after diagnosis. To date, 9 institutions have joined the cohort and initiated data collection; additional centers will be added in the coming year(s)., Conclusions: Our findings will affect clinical practice for pediatric patients with cancer by providing the first large-scale systematic comparison of the risk of subsequent cancers from proton compared with photon therapy., Competing Interests: Matthew M. Mille reports sponsored travel to scientific meetings. Daniel J. Indelicato received a grant from the National Cancer Institute within the past 36 months for participation on the National Cancer Institute Pediatric Clinical Institutional Review Board. Joshua D. Palmer received research grants from Varian Medical Systems, The Kroger Company, Genentech, and the National Institutes of Health, consultant fees from Huron Consulting, a speaker honorarium from Varian Medical Systems, and travel support from Novocure and Varian Medical Systems, and is a Novocure Advisory Board member. Sujith Baliga received a speaker honorarium from Varian Medical Center. Matthew M. Poppe received a speaker honorarium and travel support from Mevion and is an investor in PEEL Therapeutics. Derek S. Tsang is a consultant for Back Alley Film Productions, MD lawyers and received meeting registration support from Mevion Medical Systems. Torunn I. Yock received in-kind research support from MIM Software, Inc. No other disclosures were reported.

Incomplete coverage by cancer registries can lead to an underreporting of cancers and a resulting bias in risk estimates. When registries are defined by geographic region, gaps in observation can arise for individuals who reside outside of or migrate from the total registry catchment area. Moreover, the exact periods of non-observation for an individual may be unknown due to intermittent reporting of residential histories. The motivating example for this work is the U.S. Radiologic Technologist (USRT) study which ascertained cancer outcomes for a national cohort through 43 state/regional registries; similar gaps in outcome ascertainment can appear in other registry or electronic health record- based cohort studies. We propose a two-step procedure for estimating relative and absolute risk in these settings. First, using a mover stayer model fitted to individuals' known residential history, we obtain individual posterior probabilities of residing outside the registry catchment area each year. Second, we incorporate these probabilities in the survival data likelihood for competing risks to account for unobserved events. We assess the performance of the proposed method in extensive simulation studies. Compared to several simple alternative approaches, the proposed method reduces bias and improves efficiency. Finally, we apply the proposed method to a study of first primary lung cancers in the USRT cohort., (Published 2023. This article is a U.S. Government work and is in the public domain in the USA.)

Background & Aims: Incidence rates of liver cancer in most populations are two to three times higher among men than women. The higher rates among men have led to the suggestion that androgens are related to increased risk whereas oestrogens are related to decreased risk. This hypothesis was investigated in the present study via a nested case-control analysis of pre-diagnostic sex steroid hormone levels among men in five US cohorts., Methods: Concentrations of sex steroid hormones and sex hormone-binding globulin were quantitated using gas chromatography-mass spectrometry and a competitive electrochemiluminescence immunoassay, respectively. Multivariable conditional logistic regression was used to calculate odds ratios (ORs) and 95% CIs for associations between hormones and liver cancer among 275 men who subsequently developed liver cancer and 768 comparison men., Results: Higher concentrations of total testosterone (OR per one-unit increase in log 2  = 1.77, 95% CI = 1.38-2.29), dihydrotestosterone (OR = 1.76, 95% CI = 1.21-2.57), oestrone (OR = 1.74, 95% CI = 1.08-2.79), total oestradiol (OR = 1.58, 95% CI=1.22-20.05), and sex hormone-binding globulin (OR = 1.63, 95% CI = 1.27-2.11) were associated with increased risk. Higher concentrations of dehydroepiandrosterone (DHEA), however, were associated with a 53% decreased risk (OR = 0.47, 95% CI = 0.33-0.68)., Conclusions: Higher concentrations of both androgens (testosterone, dihydrotestosterone) and their aromatised oestrogenic metabolites (oestrone, oestradiol) were observed among men who subsequently developed liver cancer compared with men who did not. As DHEA is an adrenal precursor of both androgens and oestrogens, these results may suggest that a lower capacity to convert DHEA to androgens, and their subsequent conversion to oestrogens, confers a lower risk of liver cancer, whereas a greater capacity to convert DHEA confers a greater risk., Impact and Implications: This study does not fully support the current hormone hypothesis as both androgen and oestrogen levels were associated with increased risk of liver cancer among men. The study also found that higher DHEA levels were associated with lower risk, thus suggesting the hypothesis that greater capacity to convert DHEA could be associated with increased liver cancer risk among men., Competing Interests: The authors declare no conflicts of interest that pertain to this work. Please refer to the accompanying ICMJE disclosure forms for further details.

Background: Low-frequency variants play an important role in breast cancer (BC) susceptibility. Gene-based methods can increase power by combining multiple variants in the same gene and help identify target genes., Methods: We evaluated the potential of gene-based aggregation in the Breast Cancer Association Consortium cohorts including 83,471 cases and 59,199 controls. Low-frequency variants were aggregated for individual genes' coding and regulatory regions. Association results in European ancestry samples were compared to single-marker association results in the same cohort. Gene-based associations were also combined in meta-analysis across individuals with European, Asian, African, and Latin American and Hispanic ancestry., Results: In European ancestry samples, 14 genes were significantly associated (q < 0.05) with BC. Of those, two genes, FMNL3 (P = 6.11 × 10 -6 ) and AC058822.1 (P = 1.47 × 10 -4 ), represent new associations. High FMNL3 expression has previously been linked to poor prognosis in several other cancers. Meta-analysis of samples with diverse ancestry discovered further associations including established candidate genes ESR1 and CBLB. Furthermore, literature review and database query found further support for a biologically plausible link with cancer for genes CBLB, FMNL3, FGFR2, LSP1, MAP3K1, and SRGAP2C., Conclusions: Using extended gene-based aggregation tests including coding and regulatory variation, we report identification of plausible target genes for previously identified single-marker associations with BC as well as the discovery of novel genes implicated in BC development. Including multi ancestral cohorts in this study enabled the identification of otherwise missed disease associations as ESR1 (P = 1.31 × 10 -5 ), demonstrating the importance of diversifying study cohorts., (© 2023. The Author(s).)

Thyroid cancer incidence is higher in women than men, especially during the reproductive years, for reasons that remain poorly understood. Using population-based registry data from 4 Nordic countries through 2015, we examined associations of perinatal characteristics with risk of maternal thyroid cancer. Cases were women diagnosed with thyroid cancer ≥2 years after last birth (n = 7,425, 83% papillary). Cases were matched to controls (n = 67,903) by mother's birth year, country, and county of residence. Odds ratios (ORs) were estimated using conditional logistic regression models adjusting for parity. Older age at first pregnancy, postpartum hemorrhage (OR = 1.18, 95% (confidence interval) CI: 1.08, 1.29), and benign thyroid conditions (ORs ranging from 1.64 for hypothyroidism to 10.35 for thyroid neoplasms) were associated with increased thyroid cancer risk, as were higher offspring birth weight (per 1-kg increase, OR = 1.17, 95% CI: 1.12, 1.22) and higher likelihood of offspring being large for gestational age (OR = 1.26, 95% CI: 1.11, 1.43). Unmarried/noncohabiting status (OR = 0.91, 95% CI: 0.84, 0.98), maternal smoking (OR = 0.75, 95% CI: 0.67, 0.84), and preterm birth (OR = 0.90, 95% CI: 0.83, 0.98) were associated with reduced risk. Several factors (e.g., older age at first pregnancy, maternal smoking, goiter, benign neoplasms, postpartum hemorrhage, hyperemesis gravidarum, and neonatal jaundice) were associated with advanced thyroid cancer. These findings suggest that some perinatal exposures may influence maternal thyroid cancer risk., (Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2022. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

A large number of variants identified through clinical genetic testing in disease susceptibility genes, are of uncertain significance (VUS). Following the recommendations of the American College of Medical Genetics and Genomics (ACMG) and Association for Molecular Pathology (AMP), the frequency in case-control datasets (PS4 criterion), can inform their interpretation. We present a novel case-control likelihood ratio-based method that incorporates gene-specific age-related penetrance. We demonstrate the utility of this method in the analysis of simulated and real datasets. In the analyses of simulated data, the likelihood ratio method was more powerful compared to other methods. Likelihood ratios were calculated for a case-control dataset of BRCA1 and BRCA2 variants from the Breast Cancer Association Consortium (BCAC), and compared with logistic regression results. A larger number of variants reached evidence in favor of pathogenicity, and a substantial number of variants had evidence against pathogenicity - findings that would not have been reached using other case-control analysis methods. Our novel method provides greater power to classify rare variants compared to classical case-control methods. As an initiative from the ENIGMA Analytical Working Group, we provide user-friendly scripts and pre-formatted excel calculators for implementation of the method for rare variants in BRCA1 , BRCA2 and other high-risk genes with known penetrance.

Objective: Differentiated thyroid cancer (DTC) is associated with an excellent prognosis, but patients with distant metastatic DTC have a 10-year disease-specific survival (DSS) of just 50%. The incidence of distant metastatic DTC has steadily increased in the United States since the 1980s. The aim of this study was to examine trends in survival and treatment for patients with distant metastatic DTC. Methods: In this population-based, retrospective cohort study, patients with distant metastatic DTC were identified from the Surveillance, Epidemiology, and End Results-13 cancer registry program. Multivariable logistic and Cox regression analyses were used to examine factors associated with DSS and management. Annual percentage changes in treatment patterns were calculated using log-linear regression. Results: During 1992-2018, 1991 patients (69.7% white, 58.0% female, 47.5% aged ≥65 years) were diagnosed with distant metastatic DTC. Papillary thyroid cancer was the most common histological type (74.5%). While the 10-year DSS for overall DTC increased over time (95.4% for patients diagnosed in 1992-1998, 96.6% in 1999-2008, and 97.3% in 2009-2018; p  < 0.01), 10-year DSS for DTC with distant metastases did not change (50.2%, 47.3%, and 52.4%, respectively; p  = 0.48). Ten-year DSS rates were reduced for patients aged ≥65 years (28.1%), patients undergoing nonsurgical treatment with external beam radiation therapy and/or systemic therapy (6.0%), and patients undergoing no/unknown treatment (32.8%). On multivariable analysis, oncocytic carcinoma, age 65-79 and ≥80 years, male sex, node-positive disease, larger tumor size, nonsurgical treatment, and no/unknown treatment were associated with increased risk of thyroid cancer death. Between 1992 and 2018, the rate of nonsurgical treatment increased, on average, 1.3% per year (1992-1998: 22.9% vs. 2009-2018: 25.6%; p  = 0.03), and the rate of patients receiving no/unknown treatment increased 1.9% per year (1992-1998: 11.3% vs. 2009-2018: 15.6%; p  = 0.01). Patients aged 65-79 and ≥80 years were more likely than younger patients to receive nonsurgical management or no/unknown treatment. Conclusion: Patients diagnosed with distant metastatic DTC have experienced no improvement in DSS over the past three decades. An increasing proportion of patients diagnosed with distant metastatic DTC are receiving nonsurgical treatment or no/unknown treatment over time; the proportion was highest among the oldest patients.

In a previous systematic review and meta-analysis of studies reporting associations between hyper-/hypothyroidism and breast cancer incidence published through 29 January 2019, we identified a higher risk with diagnosed hyperthyroidism compared to euthyroidism, but no association with diagnosed hypothyroidism. This 2-year updated meta-analysis aims to investigate the role of menopause in this association and the dose-response relationship with blood levels of thyroid-stimulating hormone (TSH) and thyroid hormones. After the exclusion of studies with only mortality follow-up, with thyroid dysfunction evaluated as a cancer biomarker or after prior breast cancer diagnosis, we reviewed 25 studies that were published up to 01 December 2021 and identified in MEDLINE, the COCHRANE library, Embase, or Web of Science; of these, 9 were included in the previous meta-analysis. Risk estimates from 22 of the 25 studies were included in the meta-analysis and pooled using random-effects models. Compared to euthyroidism, hyperthyroidism and hypothyroidism diagnoses were associated with higher (pooled risk ratio (RR): 1.12, 95% CI: 1.06-1.18, 3829 exposed cases) and lower risks (RR = 0.93, 95% CI: 0.86-1.00, 5632 exposed cases) of breast cancer, respectively. The increased risk after hyperthyroidism was greater among postmenopausal women (RR = 1.19, 95% CI 1.09-1.30) and the decreased risk after hypothyroidism was more pronounced among premenopausal women (RR = 0.69, 95% CI 0.53-0.89). Among women with no prior history of thyroid disease, every 1 mIU/L increase in TSH level was associated with a 0.8% (95% CI > 0-1.5%) lower risk of breast cancer. In conclusion, this meta-analysis supports an association between thyroid hormone levels and breast cancer risk, which could be modified by menopausal status.

The exponential growth in the use of nuclear medicine procedures represents a general radiation safety concern and stresses the need to monitor exposure levels and radiation-related long term health effects in NM patients. In the current study, following our previous work on NCINM version 1 based on the UF/NCI hybrid phantom series, we calculated a comprehensive library of S values using the ICRP reference pediatric and adult voxel phantoms and established a library of biokinetic data from multiple ICRP Publications, which were then implemented into NCINM version 2. We calculated S values in two steps: calculation of specific absorbed fraction (SAF) using a Monte Carlo radiation transport code combined with the twelve ICRP pediatric and adult voxel phantoms for a number of combinations of source and target region pairs; derivation of S values from the SAFs using the ICRP nuclear decay data. We also adjusted the biokinetic data of 105 radiopharmaceuticals from multiple ICRP publications to match the anatomical description of the ICRP voxel phantoms. Finally, we integrated the ICRP phantom-based S values and adjusted biokinetic data into NCINM version 2. The ratios of cross-fire SAFs from NCINM 2 to NCINM 1 for the adult phantoms varied widely from 0.26 to 5.94 (mean = 1.24, IQR = 0.77-1.55) whereas the ratios for the pediatric phantoms ranged from 0.64 to 1.47 (mean = 1.01, IQR = 0.98-1.03). The ratios of absorbed dose coefficients from NCINM 2 over those from ICRP publications widely varied from 0.43 (colon for 99m Tc-ECD) to 2.57 (active marrow for 99m Tc-MAG3). NCINM 2.0 should be useful for dosimetrists and medical physicists to more accurately estimate organ doses for various nuclear medicine procedures., (© 2022 IOP Publishing Ltd.)

Follow-up of US cohort members for incident cancer is time-consuming, is costly, and often results in underascertainment when the traditional methods of self-reporting and/or medical record validation are used. We conducted one of the first large-scale investigations to assess the feasibility, methods, and benefits of linking participants in the US Radiologic Technologists (USRT) Study (n = 146,022) with the majority of US state or regional cancer registries. Follow-up of this cohort has relied primarily on questionnaires (mailed approximately every 10 years) and linkage with the National Death Index. We compared the level of agreement and completeness of questionnaire/death-certificate-based information with that of registry-based (43 registries) incident cancer follow-up in the USRT cohort. Using registry-identified first primary cancers from 1999-2012 as the gold standard, the overall sensitivity was 46.5% for self-reports only and 63.0% for both self-reports and death certificates. Among the 37.0% false-negative reports, 27.8% were due to dropout, while 9.2% were due to misreporting. The USRT cancer reporting patterns differed by cancer type. Our study indicates that linkage to state cancer registries would greatly improve completeness and accuracy of cancer follow-up in comparison with questionnaire self-reporting. These findings support ongoing development of a national US virtual pooled registry with which to streamline cohort linkages., (Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2022.)

Although NSAIDs have been associated with both reduced and increased cutaneous melanoma risk, few studies have examined these associations by ultraviolet radiation (UVR) or personal sun-sensitivity. We examined the associations between NSAID use and first primary invasive cutaneous melanoma among 58,227 non-Hispanic white participants in the United States Radiologic Technologists cohort study. Poisson regression was used to calculate rate ratios (RR) and 95% likelihood-based confidence intervals (CI), adjusting for attained age, birth cohort, and ambient UVR. No significant association of melanoma was observed for any use of NSAIDs (RR, 0.87; 95% CI, 0.71-1.09). The relative risks of melanoma for the highest categories of aspirin and other NSAID use (≥5 times per month vs. none) were 0.93 (95% CI, 0.74-1.16) and 1.02 (95% CI, 0.83-1.25), respectively. Further analyses did not reveal dose-response for trends in frequency of NSAID use or interactions with sex, UVR, eye and hair color, and skin complexion. In this large nationwide study, NSAID use was not associated with melanoma risk., Prevention Relevance: NSAIDs have been associated with both reduced and increased melanoma risk. However, few studies have examined the role of UVR or personal sun-sensitivity on these associations. Our findings strengthen the evidence that NSAID use is not associated with melanoma risk, even in sun-sensitive subgroups., (©2022 American Association for Cancer Research.)

Objectives: Physical inactivity and sedentary behaviour are associated with higher breast cancer risk in observational studies, but ascribing causality is difficult. Mendelian randomisation (MR) assesses causality by simulating randomised trial groups using genotype. We assessed whether lifelong physical activity or sedentary time, assessed using genotype, may be causally associated with breast cancer risk overall, pre/post-menopause, and by case-groups defined by tumour characteristics., Methods: We performed two-sample inverse-variance-weighted MR using individual-level Breast Cancer Association Consortium case-control data from 130 957 European-ancestry women (69 838 invasive cases), and published UK Biobank data (n=91 105-377 234). Genetic instruments were single nucleotide polymorphisms (SNPs) associated in UK Biobank with wrist-worn accelerometer-measured overall physical activity (n snps =5) or sedentary time (n snps =6), or accelerometer-measured (n snps =1) or self-reported (n snps =5) vigorous physical activity., Results: Greater genetically-predicted overall activity was associated with lower breast cancer overall risk (OR=0.59; 95% confidence interval (CI) 0.42 to 0.83 per-standard deviation (SD;~8 milligravities acceleration)) and for most case-groups. Genetically-predicted vigorous activity was associated with lower risk of pre/perimenopausal breast cancer (OR=0.62; 95% CI 0.45 to 0.87,≥3 vs. 0 self-reported days/week), with consistent estimates for most case-groups. Greater genetically-predicted sedentary time was associated with higher hormone-receptor-negative tumour risk (OR=1.77; 95% CI 1.07 to 2.92 per-SD (~7% time spent sedentary)), with elevated estimates for most case-groups. Results were robust to sensitivity analyses examining pleiotropy (including weighted-median-MR, MR-Egger)., Conclusion: Our study provides strong evidence that greater overall physical activity, greater vigorous activity, and lower sedentary time are likely to reduce breast cancer risk. More widespread adoption of active lifestyles may reduce the burden from the most common cancer in women., Competing Interests: Competing interests: MWB conducts research funded by Amgen, Novartis and Pfizer. PAF conducts research funded by Amgen, Novartis and Pfizer. He received honoraria from Roche, Novartis and Pfizer. AWK declares research funding to her institution from Myriad Genetics for an unrelated project (funding dates 2017-2019). SL declares grants and honoraria paid to her institution from Amgen, Novartis, Pfizer, Roche, and, outside the submitted work, grants and/or honoraria paid to her institution from AbbVie, Celgene, Seattle Genetics, PrIME/Medscape, Daiichi-Sankyo, Lilly, Samsung, BMS, Puma, Immunomedics, AstraZeneca, Pierre Fabre, Merck, GlaxoSmithKlein, EirGenix, and Bayer, and personal fees from Chugai; SL also has a patent EP14153692.0 pending. UM declares stock ownership in Abcodia Ltd. RAM has been a consultant for Pharmavite. No other authors have conflicts to declare., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Polygenic risk scores (PRSs) are useful for predicting breast cancer risk, but the prediction accuracy of existing PRSs in women of African ancestry (AA) remains relatively low. We aim to develop optimal PRSs for the prediction of overall and estrogen receptor (ER) subtype-specific breast cancer risk in AA women. The AA dataset comprised 9235 cases and 10 184 controls from four genome-wide association study (GWAS) consortia and a GWAS study in Ghana. We randomly divided samples into training and validation sets. We built PRSs using individual-level AA data by a forward stepwise logistic regression and then developed joint PRSs that combined (1) the PRSs built in the AA training dataset and (2) a 313-variant PRS previously developed in women of European ancestry. PRSs were evaluated in the AA validation set. For overall breast cancer, the odds ratio per standard deviation of the joint PRS in the validation set was 1.34 [95% confidence interval (CI): 1.27-1.42] with the area under receiver operating characteristic curve (AUC) of 0.581. Compared with women with average risk (40th-60th PRS percentile), women in the top decile of the PRS had a 1.98-fold increased risk (95% CI: 1.63-2.39). For PRSs of ER-positive and ER-negative breast cancer, the AUCs were 0.608 and 0.576, respectively. Compared with existing methods, the proposed joint PRSs can improve prediction of breast cancer risk in AA women., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Study Question: Are reproductive factors and exogenous hormone use associated with incidence of cutaneous melanoma while accounting for ultraviolet radiation (UVR) exposure across different life periods and sun sensitivity factors?, Summary Answer: Earlier age at menarche and late age at first birth, but not other estrogen-related factors were associated with an increased incidence rate of melanoma, with higher risks observed for earlier age at menarche and light hair color at age 15 years., What Is Known Already: Although estrogens have been recognized as photosensitizing, previous studies have reported inconsistent findings for the association of melanoma with estrogen-related factors. Most have not collected detailed skin cancer risk factors and have not thoroughly investigated effect modification by ambient UVR and sun sensitivity., Study Design, Size, Duration: Participants in the US Radiologic Technologists study, an occupational cohort of 146 022 radiologic technologists (73% women), were included and followed during the four time periods (1983-1989, 1994-1998, 2003-2005 and 2012-2014)., Participants/materials, Setting, Methods: Non-Hispanic white female participants who completed both the second (baseline) and third questionnaires, and did not report having cancer (except keratinocyte carcinoma) at baseline, were included and followed from their age at completion of the second (baseline) questionnaire until the earlier of first primary cancer diagnosis, including invasive melanoma of the skin, or completion of either the third or fourth questionnaire. Reproductive and exogenous hormonal factors were ascertained from the second (baseline) questionnaire, which also collected information on demographic, lifestyle factors and sun sensitivity factors. Ambient UVR was assigned by linking geocoded residential locations, based on self-reported residential history information collected from the third questionnaire to satellite-based ambient UVR data from the National Aeronautics and Space Administration's Total Ozone Mapping Spectrometer database. To examine the association of reproductive factors, exogenous hormone use, and first primary invasive melanoma of the skin, we used Poisson regression to calculate rate ratios (RRs) and 95% likelihood-based CIs, adjusting for attained age, birth cohort, lifetime average annual ambient UVR, contraceptives and menopausal hormone therapy use. To address the effect modification of ambient UVR exposure and sun sensitivities on melanoma risk, we conducted likelihood-ratio tests for multiplicative interaction., Main Results and the Role of Chance: Over a median follow-up time of 17.1 years, 0.95% of eligible participants had an incident first primary melanoma (n = 444). Higher melanoma incidence rates were observed in participants with older attained age, blue/green/gray eye color, blonde/red/auburn natural hair color at age 15, fair skin complexion, and higher UVR. We found an increased incidence rate of melanoma in women who experienced menarche at an earlier age (13, 12 and <12 years vs ≥14 years: RR = 1.48, 95% CI = 1.11-1.98; 1.19, 0.89-1.61; 1.26, 0.93-1.73), and in women with older age at first birth (25-29 and ≥30 years vs <25 years; 1.09, 0.86-1.39; 1.48, 1.12-1.95; P-value for trend = 0.006). However, no significant association was observed for other reproductive factors, and for all exogenous hormone use. The associations of melanoma incidence for most reproductive factors and exogenous hormone use were not modified by ambient UVR, eye color, natural hair color at age 15 and skin complexion. The exception was that natural hair color at age 15 modified the associations of melanoma for age at menarche (P-value for interaction = 0.004) and age at first birth among parous women (0.005). In participants with blonde/red/auburn natural hair color at age 15, we found increased risk of melanoma among women who experienced menarche at age 13, 12 and <12 years (vs ≥14 years: RR = 3.54, 95% CI = 1.98-6.90; 2.51, 1.37-4.98; 2.66, 1.41-5.36, respectively; P-value for trend = 0.10). However, the association between age at menarche and melanoma was null in participants with brown/black natural hair color at age 15., Limitations, Reasons for Caution: Information on reproductive history and exogenous hormone use was self-reported. We did not have information on specific doses or formulations of exogenous hormone medications or breastfeeding., Wider Implications of the Findings: Women residing in areas of high ambient UVR and those with blonde/red/auburn natural hair color may constitute an additional high-risk group in need of more frequent skin cancer screening. Identifying susceptible periods of exposure or factors that modify UVR susceptibility may aid in guiding more targeted guidelines for melanoma prevention., Study Funding/competing Interest(s): This research was supported by the Intramural Research Program, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, US Department of Health and Human Services. Authors declare no conflict of interest., Trial Registration Number: N/A., (Published by Oxford University Press 2022.)

Use of menopausal hormone therapy (MHT) is associated with increased risk for breast cancer. However, the relevant mechanisms and its interaction with genetic variants are not fully understood. We conducted a genome-wide interaction analysis between MHT use and genetic variants for breast cancer risk in 27,585 cases and 34,785 controls from 26 observational studies. All women were post-menopausal and of European ancestry. Multivariable logistic regression models were used to test for multiplicative interactions between genetic variants and current MHT use. We considered interaction p-values < 5 × 10 -8 as genome-wide significant, and p-values < 1 × 10 -5 as suggestive. Linkage disequilibrium (LD)-based clumping was performed to identify independent candidate variants. None of the 9.7 million genetic variants tested for interactions with MHT use reached genome-wide significance. Only 213 variants, representing 18 independent loci, had p-values < 1 × 10 5 . The strongest evidence was found for rs4674019 (p-value = 2.27 × 10 -7 ), which showed genome-wide significant interaction (p-value = 3.8 × 10 -8 ) with current MHT use when analysis was restricted to population-based studies only. Limiting the analyses to combined estrogen-progesterone MHT use only or to estrogen receptor (ER) positive cases did not identify any genome-wide significant evidence of interactions. In this large genome-wide SNP-MHT interaction study of breast cancer, we found no strong support for common genetic variants modifying the effect of MHT on breast cancer risk. These results suggest that common genetic variation has limited impact on the observed MHT-breast cancer risk association., (© 2022. The Author(s).)

Background: In response to evidence of overdiagnosis and overtreatment of papillary thyroid carcinoma (PTC), the 2009 and 2015 American Thyroid Association (ATA) adult guidelines recommended less extensive surgery (lobectomy vs. total thyroidectomy) and more restricted use of postsurgical radioactive iodine (RAI) in management of PTC at low risk of recurrence. In 2015, active surveillance was suggested as a viable option for some <1-cm PTCs, or microcarcinomas. The 2015 ATA pediatric guidelines similarly shifted toward more restricted use of RAI for low-risk PTCs. The impact of these recommendations on low-risk adult and pediatric PTC management remains unclear, particularly after 2015. Methods: Using data from 18 Surveillance, Epidemiology, and End Results (SEER) U.S. registries (2000-2018), we described time trends in reported first-course treatment (total thyroidectomy alone, total thyroidectomy+RAI, lobectomy, no surgery, and other/unknown) for 105,483 patients diagnosed with first primary localized PTC (without nodal/distant metastases), overall and by demographic and tumor characteristics. Results: The declining use of RAI represented the most pronounced change in management of PTCs <4 cm (44-18% during the period 2006-2018), including microcarcinomas (26-6% during the period 2007-2018). In parallel, an increasing proportion of PTCs were managed with total thyroidectomy alone (35-54% during the period 2000-2018), while more subtle changes were observed for lobectomy (declining from 23% to 17% during the period 2000-2006, stabilizing, and then rising from 17% to 24% during the period 2015-2018). Use of nonsurgical management did not meaningfully change over time, impacting <1% of microcarcinomas annually during the period 2000-2018. Similar treatment trends were observed by sex, age, race/ethnicity, metropolitan vs. nonmetropolitan residence, and insurance status. For pediatric patients (<20 years), use of RAI peaked in 2009 (59%), then decreased markedly to 11% (2018), while use of total thyroidectomy alone and, to a lesser extent, lobectomy increased. No changing treatment trends were observed for ≥4-cm PTCs. Conclusions: The declining use of RAI in management of low-risk adult and pediatric PTC is consistent with changing recommendations from the ATA practice guidelines. Post-2015 trends in use of lobectomy and nonsurgical management of low-risk PTCs, particularly microcarcinomas, were more subtle than expected; however, these trends may change as evidence regarding their safety continues to emerge.

Purpose: To describe the range of occupational badge dose readings and annualized dose records among physicians performing fluoroscopically guided interventional (FGI) procedures using job title information provided by the same 3 major medical institutions in 2009, 2012, and 2015., Materials and Methods: The Radiation Safety Office of selected hospitals was contacted to request assistance with identifying physicians in a large commercial dosimetry database. All entries judged to be uninformative of occupational doses to FGI procedure staff were excluded. Monthly and annualized doses were described with univariate statistics and box-and-whisker plots., Results: The dosimetry data set of interventional radiology staff contained 169 annual dose records from 77 different physicians and 698 annual dose records from 455 nonphysicians. The median annualized lens dose equivalent values among physicians (11.9 mSv; interquartile range [IQR], 6.9-20.0 mSv) was nearly 3-fold higher than those among nonphysician medical staff assisting with FGI procedures (4.0 mSv; IQR, 1.8-6.7 mSv) (P < .001). During the study period, without eye protection, 25% (23 of 93) of the physician annualized lens dose equivalent values may have exceeded 20 mSv; for nonphysician medical staff, this value may have been exceeded 3.5% (6 of 173) of the time. However, these values did not account for eye protection., Conclusions: The findings from this study highlight the importance of mitigating occupational dose to the eyes of medical staff, particularly physicians, performing or assisting with FGI procedures. Training on radiation protection principles, the use of personal protective equipment, and patient radiation dose management can all help ensure that the occupational radiation dose is adequately controlled., (Copyright © 2021. Published by Elsevier Inc.)

Background: Although obesity is a known risk factor, the impact of weight change on colorectal adenoma risk is less clear and could have important implications in disease prevention. We prospectively evaluated weight change in adulthood and incident colorectal adenoma., Methods: We assessed weight change during early-late (age 20 years to baseline, ie, ages 55-74 years), early-middle (20-50 years), and middle-late (50 years-baseline) adulthood using self-reported weight data in relation to incident distal adenoma in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (cases = 1053; controls = 16 576). For each period, we defined stable weight as greater than -0.5 kg to less than or equal to 1 kg/5 years, weight loss as less than or equal to -0.5 kg/5 years, and weight gain as greater than 1-2, greater than 2-3, or greater than 3 kg/5 years. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) using logistic regression; all tests were 2-sided., Results: Compared with stable weight, weight loss during early-late adulthood was associated with reduced adenoma risk (OR = 0.54, 95% CI = 0.34 to 0.86), particularly among those who were overweight or obese at age 20 years (OR = 0.39, 95% CI = 0.18 to 0.84). Results were similar for early-middle adulthood but less pronounced for middle-late adulthood. Weight gain greater than 3 kg/5 years during early-late adulthood was associated with increased risk (OR = 1.30, 95% CI = 1.07 to 1.58, P trend < .001). Findings appeared stronger among men (OR for >3 kg/5 years = 1.41, 95% CI = 1.11 to 1.80) than women (OR = 1.09, 95% CI = 0.79 to 1.50, P interaction = .21)., Conclusions: Weight loss in adulthood was associated with reduced adenoma risk, particularly for those who were overweight or obese, whereas weight gain greater than 3 kg/5 years increased risk. Findings underscore the importance of healthy weight maintenance throughout adulthood in preventing colorectal adenoma., (© The Author(s) 2022. Published by Oxford University Press.)

Germline copy number variants (CNVs) are pervasive in the human genome but potential disease associations with rare CNVs have not been comprehensively assessed in large datasets. We analysed rare CNVs in genes and non-coding regions for 86,788 breast cancer cases and 76,122 controls of European ancestry with genome-wide array data. Gene burden tests detected the strongest association for deletions in BRCA1 (P = 3.7E-18). Nine other genes were associated with a p-value < 0.01 including known susceptibility genes CHEK2 (P = 0.0008), ATM (P = 0.002) and BRCA2 (P = 0.008). Outside the known genes we detected associations with p-values < 0.001 for either overall or subtype-specific breast cancer at nine deletion regions and four duplication regions. Three of the deletion regions were in established common susceptibility loci. To the best of our knowledge, this is the first genome-wide analysis of rare CNVs in a large breast cancer case-control dataset. We detected associations with exonic deletions in established breast cancer susceptibility genes. We also detected suggestive associations with non-coding CNVs in known and novel loci with large effects sizes. Larger sample sizes will be required to reach robust levels of statistical significance., (© 2022. The Author(s).)

Background: It has been well-established that acute radiation exposures increase the risk of leukemia. However, it is still unknown whether these leukemia risk estimates could be extrapolated to occupational populations who receive repeated low-dose radiation exposure. The purpose of this study was to estimate quantified associations between low-dose radiation exposures and leukemia., Methods: The Chinese medical X-ray worker study (CMXW) included 27,011 medical X-ray workers employed at major hospitals in 24 provinces in China from 1950 to 1980, and a control population of 25,782 physicians matched by hospital, who were unexposed to X-ray equipment. Poisson regression models were used to estimate the excess relative risk (ERR) and excess absolute risk (EAR) for the incidence of leukemia associated with cumulative doses. A meta-analysis of the published literature on low-dose occupational radiation exposure and leukemia risk was also conducted., Results: The incidence rates of leukemia in X-ray workers and the control group were 6.70 and 3.39 per 100,000 person-years, respectively. Among X-ray workers, the average cumulative red bone marrow dose was 0.046 Gy. We found a positive relationship between 2-year lagged cumulative red bone marrow dose and risk of leukemia excluding chronic lymphocytic leukemia (CLL) (ERR = 0.66 per 100 mGy, 90% CI: 0.09, 1.53; EAR = 0.29 per 10 4 PY-100 mGy, 90% CI: 0.07, 0.56). The excess risk was largely driven by myeloid leukemia (ERR = 1.06 per 100 mGy, 90% CI: 0.22, 2.51). Based on the meta-analysis, the pooled ERR at 100 mGy was 0.19 (95% CI: 0.08, 0.31)., Conclusion: This study provides strong evidence of a positive and linear doseresponse relationship between cumulative red bone marrow dose and the incidence of non-CLL leukemia., Competing Interests: The authors declare that they have no conflict of interests., (© 2022 Chinese National Cancer Center. Published by Elsevier B.V.)

Background: Genome-wide association studies (GWAS) have identified multiple common breast cancer susceptibility variants. Many of these variants have differential associations by estrogen receptor (ER) status, but how these variants relate with other tumor features and intrinsic molecular subtypes is unclear., Methods: Among 106,571 invasive breast cancer cases and 95,762 controls of European ancestry with data on 173 breast cancer variants identified in previous GWAS, we used novel two-stage polytomous logistic regression models to evaluate variants in relation to multiple tumor features (ER, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and grade) adjusting for each other, and to intrinsic-like subtypes., Results: Eighty-five of 173 variants were associated with at least one tumor feature (false discovery rate < 5%), most commonly ER and grade, followed by PR and HER2. Models for intrinsic-like subtypes found nearly all of these variants (83 of 85) associated at p < 0.05 with risk for at least one luminal-like subtype, and approximately half (41 of 85) of the variants were associated with risk of at least one non-luminal subtype, including 32 variants associated with triple-negative (TN) disease. Ten variants were associated with risk of all subtypes in different magnitude. Five variants were associated with risk of luminal A-like and TN subtypes in opposite directions., Conclusion: This report demonstrates a high level of complexity in the etiology heterogeneity of breast cancer susceptibility variants and can inform investigations of subtype-specific risk prediction., (© 2021. The Author(s).)

Background: Mutually increased risks for thyroid and breast cancer have been reported, but the contribution of etiologic factors versus increased medical surveillance to these associations is unknown., Methods: Leveraging large-scale US population-based cancer registry data, we used standardized incidence ratios (SIRs) to investigate the reciprocal risks of thyroid and breast cancers among adult females diagnosed with a first primary invasive, non-metastatic breast cancer (N = 652,627) or papillary thyroid cancer (PTC) (N = 92,318) during 2000-2017 who survived ≥1-year., Results: PTC risk was increased 1.3-fold [N = 1434; SIR = 1.32; 95 % confidence interval (CI) = 1.25-1.39] after breast cancer compared to the general population. PTC risk declined significantly with time since breast cancer (Poisson regression = P trend <0.001) and was evident only for tumors ≤2 cm in size. The SIRs for PTC were higher after hormone-receptor (HR)+ (versus HR-) and stage II or III (versus stage 0-I) breast tumors. Breast cancer risk was increased 1.2-fold (N = 2038; SIR = 1.21; CI = 1.16-1.26) after PTC and was constant over time since PTC but was only increased for stage 0-II and HR + breast cancers., Conclusion: Although some of the patterns by latency, stage and size are consistent with heightened surveillance contributing to the breast-thyroid association, we cannot exclude a role of shared etiology or treatment effects., (Published by Elsevier Ltd.)

Background: Cutaneous basal cell carcinoma (BCC) has long been associated with UV radiation (UVR) exposure, but data are limited on risks by anatomic site., Methods: We followed 63,912 cancer-free White U.S. radiologic technologists from cohort entry (1983-1989/1994-1998) to exit (date first BCC via 2003-2005 questionnaire). We estimated associations between cumulative ambient UVR and relative/absolute risks of self-reported BCC by anatomic location via Poisson models., Results: For incident first primary BCC in 2,124 subjects (mean follow-up, 16.9 years) log[excess relative risks] (ERR) of BCC per unit cumulative ambient UVR = 1.27/MJ cm -2 [95% confidence interval (CI): 0.86-1.68; P trend = 0.153). However, excess absolute risks of BCC per unit cumulative ambient UVR were large for the head/neck = 5.46/MJ cm P = 0.153). However, excess absolute risks of BCC per unit cumulative ambient UVR were large for the head/neck = 5.46/MJ cm -2 /10 4 person-year (95% CI: 2.92-7.36; P trend < 0.001), smaller for the trunk (2.56; 95% CI: 1.26-3.33; P trend = 0.003), with lesser increases elsewhere. There were lower relative risks, but higher absolute risks, for those with Gaelic ancestry ( P < 0.001), also higher absolute risks among those with fair complexion, but relative and absolute risks were not generally modified by other constitutional, lifestyle or medical factors for any anatomic sites. Excess absolute and relative risk was concentrated 5-15 years before time of follow-up., Conclusions: BCC relative and absolute risk rose with increasing cumulative ambient UVR exposure, with absolute risk highest for the head/neck, to a lesser extent in the trunk., Impact: These associations should be evaluated in other White and other racial/ethnic populations along with assessment of possible modification by time outdoors, protective, and behavioral factors., (©2021 American Association for Cancer Research.)

Background: Despite a modest association between tobacco smoking and breast cancer risk reported by recent epidemiological studies, it is still equivocal whether smoking is causally related to breast cancer risk., Methods: We applied Mendelian randomisation (MR) to evaluate a potential causal effect of cigarette smoking on breast cancer risk. Both individual-level data as well as summary statistics for 164 single-nucleotide polymorphisms (SNPs) reported in genome-wide association studies of lifetime smoking index (LSI) or cigarette per day (CPD) were used to obtain MR effect estimates. Data from 108,420 invasive breast cancer cases and 87,681 controls were used for the LSI analysis and for the CPD analysis conducted among ever-smokers from 26,147 cancer cases and 26,072 controls. Sensitivity analyses were conducted to address pleiotropy., Results: Genetically predicted LSI was associated with increased breast cancer risk (OR 1.18 per SD, 95% CI: 1.07-1.30, P = 0.11 × 10 -2 ), but there was no evidence of association for genetically predicted CPD (OR 1.02, 95% CI: 0.78-1.19, P = 0.85). The sensitivity analyses yielded similar results and showed no strong evidence of pleiotropic effect., Conclusion: Our MR study provides supportive evidence for a potential causal association with breast cancer risk for lifetime smoking exposure but not cigarettes per day among smokers., (© 2021. The Author(s).)

Background: Polygenic risk scores (PRSs) have been demonstrated to identify women of European, Asian, and Latino ancestry at elevated risk of developing breast cancer (BC). We evaluated the performance of existing PRSs trained in European ancestry populations among women of African ancestry., Methods: We assembled genotype data for women of African ancestry, including 9241 case subjects and 10 193 control subjects. We evaluated associations of 179- and 313-variant PRSs with overall and subtype-specific BC risk. PRS discriminatory accuracy was assessed using area under the receiver operating characteristic curve. We also evaluated a recalibrated PRS, replacing the index variant with variants in each region that better captured risk in women of African ancestry and estimated lifetime absolute risk of BC in African Americans by PRS category., Results: For overall BC, the odds ratio per SD of the 313-variant PRS (PRS313) was 1.27 (95% confidence interval [CI] = 1.23 to 1.31), with an area under the receiver operating characteristic curve of 0.571 (95% CI = 0.562 to 0.579). Compared with women with average risk (40th-60th PRS percentile), women in the top decile of PRS313 had a 1.54-fold increased risk (95% CI = 1.38-fold to 1.72-fold). By age 85 years, the absolute risk of overall BC was 19.6% for African American women in the top 1% of PRS313 and 6.7% for those in the lowest 1%. The recalibrated PRS did not improve BC risk prediction., Conclusion: The PRSs stratify BC risk in women of African ancestry, with attenuated performance compared with that reported in European, Asian, and Latina populations. Future work is needed to improve BC risk stratification for women of African ancestry., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Importance: Whether radioactive iodine (RAI) therapy for hyperthyroidism can increase cancer risk remains a controversial issue in medicine and public health., Objectives: To examine site-specific cancer incidence and mortality and to evaluate the radiation dose-response association after RAI treatment for hyperthyroidism., Data Sources: The Medline and Cochrane Library electronic databases, using the Medical Subject Headings terms and text keywords, and Embase, using Emtree, were screened up to October 2020., Study Selection: Study inclusion criteria were as follows: (1) inclusion of patients treated for hyperthyroidism with RAI and followed up until cancer diagnosis or death, (2) inclusion of at least 1 comparison group composed of individuals unexposed to RAI treatment (eg, the general population or patients treated for hyperthyroidism with thyroidectomy or antithyroid drugs) or those exposed to different administered doses of RAI, and (3) inclusion of effect size measures (ie, standardized incidence ratio [SIR], standardized mortality ratio [SMR], hazard ratio [HR], or risk ratio [RR])., Data Extraction and Synthesis: Two independent investigators extracted data according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Overall quality assessment followed the recommendations of United Nations Scientific Committee on the Effects of Atomic Radiation. The SIR and SMRs and the RRs and HRs were pooled using random-effects meta-analysis., Main Outcomes and Measures: Cancer incidence and mortality for exposure vs nonexposure to RAI therapy and by level of RAI administered activity., Results: Based on data from 12 studies including 479 452 participants, the overall pooled cancer incidence ratio was 1.02 (95% CI, 0.95-1.09) and the pooled cancer mortality ratio was 0.98 (95% CI, 0.92-1.04) for exposure vs nonexposure to RAI therapy. No statistically significant elevations in risk were observed for specific cancers except thyroid cancer incidence (SIR, 1.86; 95% CI, 1.19-2.92) and mortality (SMR, 2.22; 95% CI, 1.37-3.59). However, inability to control for confounding by indication and other sources of bias were important limitations of studies comparing RAI exposure with nonexposure. In dose-response analysis, RAI was significantly associated with breast and solid cancer mortality (breast cancer mortality, per 370 MBq: 1.35; P = .03; solid cancer mortality, per 370 MBq: 1.14; P = .01), based on 2 studies., Conclusions and Relevance: In this meta-analysis, the overall pooled cancer risk after exposure to RAI therapy vs nonexposure was not significant, whereas a linear dose-response association between RAI therapy and solid cancer mortality was observed. These findings suggest that radiation-induced cancer risks following RAI therapy for hyperthyroidism are small and, in observational studies, may only be detectable at higher levels of administered dose.

Background Occupational doses to most medical radiation workers have declined substantially since the 1950s because of improvements in radiation protection practices. However, different patterns may have emerged for radiologic technologists working with nuclear medicine because of the higher per-procedure doses and increasing workloads. Purpose To summarize annual occupational doses during a 36-year period for a large cohort of U.S. radiologic technologists and to compare dose between general radiologic technologists and those specializing in nuclear medicine procedures. Materials and Methods Annual personal dose equivalents (referred to as doses ) from 1980 to 2015 were summarized for 58 434 (62%) participants in the U.S. Radiologic Technologists (USRT) cohort who responded to the most recent mailed work history survey (years 2012-2014) and reported never regularly performing interventional procedures. Doses were partitioned according to the performance of nuclear medicine (yes or no, frequency, procedure type) by calendar year. Annual dose records were described by using summary statistics (eg, median and 25th and 75th percentiles). Results Median annual doses related to performance of general radiologic procedures decreased from 0.60 mSv (interquartile range [IQR], 0.10-1.9 mSv) in 1980 to levels below the limits of detection by 2015, whereas annual doses related to performance of nuclear medicine procedures remained relatively high during this period (median, 1.2 mSv; IQR, 0.12-3.0 mSv). Higher median annual doses were associated with more frequent (above vs below the median) performance of diagnostic nuclear medicine procedures (≥35 vs <35 times per week; 1.6 mSv [IQR, 0.30-3.3 mSv] and 0.9 mSv [IQR, 0.10-2.6 mSv]). Higher and more variable annual doses were associated with more frequent performance of cardiac nuclear medicine (≥10 times per week) and PET (nine or more times per week) examinations (median, 1.6 mSv [IQR, 0.30-2.2 mSv] and 2.2 mSv [IQR, 0.10-4.6 mSv], respectively). Conclusion Annual doses to U.S. radiologic technologists performing general radiologic procedures declined during a 36-year period. However, consistently higher and more variable doses were associated with the performance of nuclear medicine procedures, particularly cardiac nuclear medicine and PET procedures. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Mettler and Guiberteau in this issue.