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Breastfeeding is inversely associated with breast cancer risk but the associations of breastfeeding with mammographic breast density (MBD) are not clear. We investigated the association between breastfeeding and volumetric measures of MBD [volumetric percent density (VPD), dense volume (DV), and non-dense volume (NDV)] and evaluated whether it differs by race, menopausal status, and body mass index (BMI). The study population was comprised of 964 women (67% non-Hispanic White, 29% non-Hispanic Black) who had screening mammography at Washington University School of Medicine, St. Louis, MO. VPD, DV and NDV were log10 transformed. We performed multivariable linear regression models adjusted for age, BMI, family history of breast cancer, race, and age at menarche among all participants and exclusively in parous women. Mean age was 50.7 years. VPD was 12% lower among women who breastfed 0–6 months, [10β = 0.88, 95% confidence interval (CI; 0.79–0.98)] compared with nulliparous women. Breastfeeding was not associated with VPD among women who breastfed >7 months. Breastfeeding was inversely associated with DV [parous never breastfed: 10β = 0.93; 95% CI (0.83–1.04), breastfed 0–6 months: 10β = 0.91, 95% CI (0.79–1.05), breastfed 7–12 months: 10β = 0.94; 95% CI (0.81–1.10), breastfed >12 months: 10β = 0.87, 95% CI (0.78–0.98), Ptrend = 0.03]. BMI modified the association between breastfeeding and VPD. Women who breastfed for 0–6 months and had a BMI < 25 kg/m2 had lower VPD compared with nulliparous women, but among women with a BMI ≥ 25 kg/m2 there was no association (Pinteraction = 0.04). In this diverse study population, the association of breastfeeding with VPD appears to be modified by BMI, but not by race or menopausal status. Future research exploring the associations of breastfeeding with other mammographic features are needed. Prevention Relevance: Breastfeeding for up to 6 months may be associated with lower VPD among women with a BMI < 25 kg/m2. The potential role of MBD in mediating the associations of breastfeeding with breast cancer risk in a select group of women deserves further evaluation. See related Spotlight, p. 309

To determine if the COVID-19 pandemic has further exacerbated racial disparities in late-stage presentation of breast, colorectal, lung, and prostate cancers.We conducted a registry-based retrospective study of patients with newly reported diagnoses of breast, colorectal, lung, and prostate cancers between March 2019-June 2019 (pre-COVID-19) and March 2020-June 2020 (early-COVID-19). We compared the volume of new diagnoses and stage at presentation according to race between both periods.During the study period, a total of 3528 patients had newly diagnosed cancer; 3304 of which had known disease stages and were included in the formal analyses. 467 (14.1%) were Blacks, and 2743 were (83%) Whites. 1216 (36.8%) had breast, 415 (12.6%) had colorectal, 827 (25%) had lung, and 846 (25.6%) had prostate cancers, respectively. The pre-COVID-19 period included 2120 (64.2%), and the early-COVID-19 period included 1184 (35.8%), representing a proportional 44.2% decline in the volume of new cases of breast, colorectal, lung, and prostate cancers, p 0.0001. Pre-COVID-19, 16.8% were diagnosed with metastatic disease, versus 20.4% early-COVID-19, representing a proportional increase of 21.4% in the numbers of new cases with metastatic disease, p = 0.01. There was a non-significant proportional decline of 1.9% in Black patients diagnosed with non-metastatic breast, colorectal, lung, and prostate cancers early-COVID-19 (p = 0.71) and a non-significant proportional increase of 7% in Black patients diagnosed with metastatic disease (p = 0.71). Difference-in-difference analyses showed no statistically significant differences in metastatic presentation comparing Black to White patients.While we identified substantial reductions in the volume of new cancer diagnoses and increases in metastatic presentations due to the COVID-19 pandemic, the impact was similar for White and Black patients.

Background:Physical activity and obesity are well-established factors of colorectal cancer risk and prognosis. Here, we investigate associations of individual and combined physical activity and body mass index (BMI) groups with proinflammatory biomarkers in colorectal cancer patients.Methods:Self-reported physical activity levels were classified as “active” (≥8.75 MET-hours/week) versus “inactive” (n = 579 stage I–IV colorectal cancer patients enrolled in the ColoCare Study. BMI [normal weight (≥18.5–2), overweight (≥25–2), and obese (≥30 kg/m2)] was abstracted from medical records. Patients were classified into four combinations of physical activity levels and BMI. Biomarkers [C-reactive protein (CRP), SAA, IL6, IL8, and TNFα] in presurgery serum samples were measured using the Mesoscale Discovery Platform. Regression models were used to compute relative percent differences in biomarker levels by physical activity and BMI groups.Results:“Inactive” patients had non-statistically significant higher IL6 levels compared with “active” patients (+36%, P = 0.10). “Obese” patients had 88% and 17% higher CRP and TNFα levels compared with “normal weight” patients (P = 0.03 and 0.02, respectively). Highest CRP levels were observed among “overweight or obese/inactive” compared with “normal weight/active” patients (P = 0.03).Conclusions:We provide evidence of associations between individual and combined physical activity and BMI groups with proinflammatory biomarkers. Although BMI was identified as the key driver of inflammation, biomarker levels were higher among “inactive” patients across BMI groups.Impact:This is the largest study in colorectal cancer patients investigating associations of energy balance components with inflammatory biomarkers. Our results suggest that physical activity may reduce obesity-induced inflammation in colorectal cancer patients and support the design of randomized controlled trials testing this hypothesis.

Supplementary Data from Associations of Individual and Combined Physical Activity and Body Mass Index Groups with Proinflammatory Biomarkers among Colorectal Cancer Patients

Background: Cell-to-cell adhesion and angiogenesis are hallmarks of cancer. No studies have examined associations of adhesion molecules and angiogenesis biomarkers with clinical outcomes in colorectal cancer. Methods: In presurgery serum from n = 426 patients with colorectal cancer (stage I–III), we investigated associations of CRP, SAA, adhesion molecules (sICAM-1, sVCAM-1), and angiogenesis markers (VEGF-A and VEGF-D) with overall survival (OS), disease-free survival (DFS), and risk of recurrence. We computed HRs and 95% confidence intervals; adjusted for age, sex, BMI, stage, site, and study site, stratified by tumor site in exploratory analyses. Results: N = 65 (15%) were deceased, and 39 patients (14%) had a recurrence after a median follow-up of 31 months. We observed significant associations of biomarkers with OS, DFS, and risk of recurrence on a continuous scale and comparing top to bottom tertile, with HRs ranging between 1.19 and 13.92. CRP was associated with risk of death and recurrence in patients in the top tertile compared with patients in the bottom tertile, for example, risk of recurrence HRQ3-Q1: 13.92 (1.72–112.56). Significant heterogeneity between biomarkers and clinical outcomes was observed in stratified analysis by tumor site for CRP, SAA, sICAM-1, sVCAM-1, and VEGF-D. VEGF-D was associated with a 3-fold increase in risk of death for rectal cancer (HRlog2: 3.26; 95% CI, 1.58–6.70) compared with no association for colon cancer (HRlog2: 0.78; 95% CI, 0.35–1.73; Pheterogenity = 0.01). Conclusions: Adhesion molecules and angiogenesis biomarkers are independent prognostic markers for colorectal cancer, with differences by tumor site. Impact: There is need for tailored treatment for colon and rectal cancer.

There is limited information on how the COVID-19 pandemic has changed health behaviors among cancer patients. We examined changes in exercise behaviors since the pandemic and identified characteristics associated with these changes among cancer patients.Cancer patients (n = 1,210) completed a survey from August to September 2020 to assess COVID-19 pandemic-related changes in health behaviors and psychosocial factors. Patients were categorized into three groups: exercising less, exercising did not change, and exercising more. Patient characteristics were compared by exercise groups.One-third of the patients reported a decreased amount of regular exercise, while 10% reported exercising more during the pandemic. Patients who exercised less were more likely to be unemployed/retired and have poor health status and psychosocial stressors such as disruptions in daily life while less likely to be former smokers (all p 0.05). In contrast, patients who exercised more were younger, had stage IV diagnosis, and also reported disruptions in daily life (all p 0.05). Patients who were living in rural areas were also more likely not to experience changes in exercise habits (all p 0.05), although rural-urban status was not identified as a strong predictor.A significant proportion of cancer patients experienced changes in exercise habits, especially exercising less, during the first 6 months of the COVID-19 pandemic. Age, employment status, tumor stage, health status, smoking status, and psychosocial factors were associated with changes in exercise behaviors. Our results highlight the importance of promoting physical activity guidelines for cancer survivorship during the COVID-19 pandemic and may help improve the identification of cancer patients susceptible to exercising less.

INTRODUCTION: Telomere shortening, as seen with aging, can cause chromosomal instability and promote cancer progression. We investigated the association between circulating telomere length and overall and disease-free survival in a sub-cohort of patients with colorectal cancer. METHODS: Baseline genomic DNA from blood leukocytes was extracted from N=92 newly diagnosed stage I-IV patients with colorectal cancer enrolled at the ColoCare Study site in Heidelberg, Germany. Detailed information on clinicodemographic (including age) and lifestyle risk factors, and clinical outcomes (including recurrence and survival) was collected. Telomere length was measured in DNA using multiplex quantitative polymerase chain reaction. Kaplan Meier survival curves were generated comparing shorter to longer telomere lengths with log-rank testing. RESULTS: The mean T/S ratio for study patients was 0.5 (range: 0.3-0.9). Shorter telomeres were associated with older age at baseline. Patients with shorter telomeres experienced a worse overall and disease-free survival, although this association did not reach statistical significance. Kaplan-Meier survival curves for those with circulating telomere length below vs. above the median showed poorer overall (log-rank p=0.31) and disease-free survival (long-rank p=0.23). CONCLUSIONS: Our results suggest that individuals with shorter telomeres, as seen with aging, may experience a worse overall and disease-free survival after colorectal cancer diagnosis. Larger sample sizes with longer follow-up are needed to further evaluate telomere length as a prognostic biomarker in colorectal cancer progression.

Supplemental Figure 1: Flowchart displaying how we arrived at the final analytic sample. Among the women recruited to the study, 127 were missing breastfeeding duration and 32 were missing values for all of the MBD measures. An additional 18 participants were missing values for one of the confounding variables; 11 women were missing age at menarche, 1 woman was missing BMI and 6 women were missing information about family history of breast cancer.

Supplemental Table 1 shows results from IPW analysis.

Breastfeeding is inversely associated with breast cancer risk but the associations of breastfeeding with mammographic breast density (MBD) are not clear. We investigated the association between breastfeeding and volumetric measures of MBD [volumetric percent density (VPD), dense volume (DV), and non-dense volume (NDV)] and evaluated whether it differs by race, menopausal status, and body mass index (BMI). The study population was comprised of 964 women (67% non-Hispanic White, 29% non-Hispanic Black) who had screening mammography at Washington University School of Medicine, St. Louis, MO. VPD, DV and NDV were log10 transformed. We performed multivariable linear regression models adjusted for age, BMI, family history of breast cancer, race, and age at menarche among all participants and exclusively in parous women. Mean age was 50.7 years. VPD was 12% lower among women who breastfed 0–6 months, [10β = 0.88, 95% confidence interval (CI; 0.79–0.98)] compared with nulliparous women. Breastfeeding was not associated with VPD among women who breastfed >7 months. Breastfeeding was inversely associated with DV [parous never breastfed: 10β = 0.93; 95% CI (0.83–1.04), breastfed 0–6 months: 10β = 0.91, 95% CI (0.79–1.05), breastfed 7–12 months: 10β = 0.94; 95% CI (0.81–1.10), breastfed >12 months: 10β = 0.87, 95% CI (0.78–0.98), Ptrend = 0.03]. BMI modified the association between breastfeeding and VPD. Women who breastfed for 0–6 months and had a BMI < 25 kg/m2 had lower VPD compared with nulliparous women, but among women with a BMI ≥ 25 kg/m2 there was no association (Pinteraction = 0.04). In this diverse study population, the association of breastfeeding with VPD appears to be modified by BMI, but not by race or menopausal status. Future research exploring the associations of breastfeeding with other mammographic features are needed.Prevention Relevance:Breastfeeding for up to 6 months may be associated with lower VPD among women with a BMI < 25 kg/m2. The potential role of MBD in mediating the associations of breastfeeding with breast cancer risk in a select group of women deserves further evaluation.

Mammographic breast density (MBD) is a risk factor for breast cancer, but its molecular basis is poorly understood. Growth factors stimulate cellular and epithelial proliferation and could influence MBD via these mechanisms. Studies investigating the associations of circulating growth factors with MBD have, however, yielded conflicting results especially in postmenopausal women. We, therefore, investigated the associations of plasma growth factor gene expression [insulin-like growth factor (IGF)-1, IGF-binding protein 3, FGF-1, FGF-12, TGFβ1 and bone morphogenetic protein (BMP)-2] with MBD in postmenopausal women. We used NanoString nCounter platform to quantify plasma growth factor gene expression and Volpara to evaluate volumetric MBD measures. We investigated the associations of growth factor gene expression with MBD using both multiple linear regression (fold change) and multinomial logistic regression models, adjusted for potential confounders. The mean age of the 368 women enrolled was 58 years (range, 50–64). In analyses using linear regression models, one unit increase in IGF-1 gene expression was associated with a 35% higher volumetric percent density (VPD, 1.35; 95% confidence interval (CI), 1.13–1.60; P = 0.001). There were suggestions that TGFβ1 gene expression was positively associated with VPD while BMP-2 gene expression was inversely associated with VPD, but these were not statistically significant. In analyses using multinomial logistic regression, TGFβ1 gene expression was 33% higher (OR = 1.33; 95% CI, 1.13–1.56; P = 0.0008) in women with extremely dense breasts than those with almost entirely fatty breasts. There were no associations between growth factor gene expression and dense volume or nondense volume. Our study provides insights into the associations of growth factors with MBD in postmenopausal women and requires confirmation in other study populations.Prevention Relevance:Mammographic breast density is a strong risk factor for breast cancer. Understanding its underlying biological mechanisms could have utility in breast cancer prevention.

The receptor activator of nuclear factor-κB (RANK) pathway plays essential roles in breast development. Mammographic density is a strong risk factor for breast cancer, especially in premenopausal women. We, therefore, investigated the associations of circulating RANK and soluble RANK ligand (sRANKL) with mammographic density in premenopausal women. Mammographic density was measured as volumetric percent density in 365 cancer-free premenopausal women (mean age, 47.5 years) attending screening mammogram at the Washington University School of Medicine (St. Louis, MO). We used linear regression models adjusted for confounders, to compare the least-square means of volumetric percent density across tertiles of circulating RANK and sRANKL. Furthermore, because RANKL levels in mammary tissue are modulated by progesterone, we stratified analyses by progesterone levels. The mean volumetric percent density increased across tertiles of circulating RANK from 8.6% in tertile 1, to 8.8% in tertile 2, and 9.5% in tertile 3 (Ptrend = 0.02). For sRANKL, the mean volumetric percent density was 8.5% in tertile 1, 9.4% in tertile 2, and 9.0% in tertile 3 (Ptrend = 0.30). However, when restricted to women with higher progesterone levels, the mean volumetric percent density increased from 9.1% in sRANKL tertile 1 to 9.5% in tertile 2, and 10.1% in tertile 3 (Ptrend = 0.01). Circulating RANK was positively associated with volumetric percent density, while circulating sRANKL was positively associated with volumetric percent density among women with higher progesterone levels. These findings support the inhibition of RANKL signaling as a pathway to reduce mammographic density and possibly breast cancer incidence in high-risk women with dense breasts.

Supplementary Table from Plasma Growth Factor Gene Expression and Mammographic Breast Density in Postmenopausal Women

Human chorionic gonadotropin (hCG) is necessary for the maintenance of early pregnancy and promotes normal breast cell differentiation. Administered hCG reduces risk of carcinogen-induced breast cancer in animal models, and higher circulating hCG concentrations were associated with significantly lower long-term risk of breast cancer in a prior nested case–control study. In this study, we investigated early-pregnancy hCG concentrations and subsequent breast cancer risk. We conducted a nested case–control study with 1,191 cases and 2,257 controls (matched on age and date at blood collection) in the Finnish Maternity Cohort, a cohort with serum samples from 98% of pregnancies registered in Finland since 1983. This study included women with a serum sample collected early (Q4 vs. Q1, 1.10; 95% CI, 0.64–1.89; ≥15 years, ORQ4 vs. Q1, 1.36; 95% CI, 0.86–2.13; pheterogeneity = 0.62). This large prospective study does not support an inverse relationship between early pregnancy serum hCG concentrations and breast cancer risk. Cancer Res; 77(1); 134–41. ©2016 AACR.

Supplemental Table 1. Distribution of Covariates by hCG Quartiles: Finnish Maternity Cohort

BACKGROUND: Genetic variation in one-carbon metabolism may affect nutrient concentrations and biological functions. However, data on genetic variants associated with blood biomarkers of one-carbon metabolism in US postmenopausal women are limited, and whether these associations were affected by the nationwide folic acid (FA) fortification program is unclear. OBJECTIVES: We investigated associations between genetic variants and biomarkers of one-carbon metabolism using data from the Women's Health Initiative Observational Study. METHODS: In 1573 non-Hispanic White (NHW) and 282 Black/African American, American Indian/Alaska Native, Asian/Pacific Islander, and Hispanic/Latino women aged 50–79 y, 288 nonsynonymous and tagging single-nucleotide variants (SNVs) were genotyped. RBC folate, plasma folate, pyridoxal-5′-phosphate (PLP), vitamin B-12, homocysteine, and cysteine concentrations were determined in 12-h fasting blood. Multivariable linear regression tested associations per variant allele and for an aggregated genetic risk score. Effect modifications before, during, and after nationwide FA fortification were examined. RESULTS: After correction for multiple comparisons, among NHW women, 5,10-methylenetetrahydrofolate reductase (MTHFR) rs1801133 (677C→T) variant T was associated with lower plasma folate (−13.0%; 95% CI: −17.3%, −8.6%) and higher plasma homocysteine (3.5%; 95% CI: 1.7%, 5.3%) concentrations. Other associations for nonsynonymous SNVs included DNMT3A rs11695471 (T→A) with plasma PLP; EHMT2 rs535586 (G→A), TCN2 rs1131603 (L349S A→G), and TCN2 rs35838082 (R188W G→A) with plasma vitamin B-12; CBS rs2851391 (G→A) with plasma homocysteine; and MTHFD1 rs2236224 (G→A) and rs2236225 (R653Q G→A) with plasma cysteine. The influence of FA fortification on the associations was limited. Highest compared with lowest quartiles of aggregated genetic risk scores from SNVs in MTHFR and MTRR were associated with 14.8% to 18.9% lower RBC folate concentrations. Gene–biomarker associations were similar in women of other races/ethnicities. CONCLUSIONS: Our findings on genetic variants associated with several one-carbon metabolism biomarkers may help elucidate mechanisms of maintaining B vitamin status in postmenopausal women.

PurposeThe Joanne Knight Breast Health Cohort was established to link breast cancer risk factors, mammographic breast density, benign breast biopsies and associated tissue markers, and blood markers in a diverse population of women undergoing routine mammographic screening to study risk factors and validate models for breast cancer risk prediction.MethodsWomen were recruited from November 2008 to April 2012 through the mammography service at the Joanne Knight Breast Health Center at Washington University in St. Louis, Missouri. Baseline questionnaire risk factors, blood, and screening mammograms were collected from 12,153 women. Of these, 1,672 were excluded for prior history of any cancer (except non-melanoma skin) or diagnosis of breast cancer within 6 months of blood draw/registration for the study, for a total of 10,481 women. Follow-up is through linking to electronic health records, tumor registry, and death register. Routine screening mammograms are collected every 1–2 years and incident benign breast biopsies and cancers are identified through record linkage to pathology and tumor registries. Formal fixed tissue samples are retrieved and stored for analysis. County-level measures of structural inequality were derived from publicly available resources.ResultsCohort Composition: median age at entry was 54.8 years and 26.7% are African American. Through 2020, 74% of participants have had a medical center visit within the past year and 80% within the past 2 years representing an average of 9.7 person-years of follow-up from date of blood draw per participant. 9,997 women are continuing in follow-up. Data collected at baseline include breast cancer risk factors, plasma and white blood cells, and mammograms prior to baseline, at baseline, and during follow-up.ConclusionThis cohort assembled and followed in a routine mammography screening and care setting that serves a diverse population of women in the St. Louis region now provides opportunities to integrate study of questionnaire measures, plasma and DNA markers, benign and malignant tissue markers, and repeated breast image features into prospective evaluation for breast cancer etiology and outcomes.

Background:Patients with colorectal cancer commonly suffer from complex psychological distress. Elevated distress may be linked to systemic biomarkers. We investigated associations of biomarkers of inflammation and angiogenesis with cancer-related distress (CTXD) score.Methods:N = 315 patients (stage I–IV) from 2 centers of the ColoCare Study were included: Huntsman Cancer Institute and University of Heidelberg. Biomarkers (e.g., IL6, VEGF-A, VEGF-D) were measured in serum collected pre-surgery and 12 months thereafter. The CTXD overall score and 4 subscales were collected 12 months after surgery and dichotomized to investigate biomarkers as predictors of distress 12 months after surgery; adjusted for age, sex, body mass index, tumor stage, center, and baseline levels of biomarkers.Results:Doubling of IL6 predicted future increased risk of overall distress [odds ratio (OR), 1.20; 95% confidence interval (CI), 1.02–1.41; P = 0.03]. VEGF-A–predicted future increased risk of high family strain (VEGF-A: OR, 1.21; 95% CI, 1.01–1.44; P = 0.04) and VEGF-D was associated with medical and financial demands (OR, 1.34; 95% CI, 1.01–1.74; P = 0.03).Conclusions:This is the first study to show that systemic biomarkers are significantly associated with future CTXD score. Distress was not measured at baseline; we cannot rule out ongoing associations of inflammation and distress throughout treatment versus a direct effect of inflammation on distress. Nonetheless, these data add to evidence that biobehavioral processes interact and that systemic biomarkers are associated with cancer-related distress one year after surgery.Impact:Exercise and diet interventions that lower systemic cytokine levels may impact longer-term CTXD score and improve quality of life of patients with colorectal cancer.

Background: Physical activity and obesity are well-established factors of colorectal cancer risk and prognosis. Here, we investigate associations of individual and combined physical activity and body mass index (BMI) groups with proinflammatory biomarkers in colorectal cancer patients. Methods: Self-reported physical activity levels were classified as “active” (≥8.75 MET-hours/week) versus “inactive” ( Results: “Inactive” patients had non-statistically significant higher IL6 levels compared with “active” patients (+36%, P = 0.10). “Obese” patients had 88% and 17% higher CRP and TNFα levels compared with “normal weight” patients (P = 0.03 and 0.02, respectively). Highest CRP levels were observed among “overweight or obese/inactive” compared with “normal weight/active” patients (P = 0.03). Conclusions: We provide evidence of associations between individual and combined physical activity and BMI groups with proinflammatory biomarkers. Although BMI was identified as the key driver of inflammation, biomarker levels were higher among “inactive” patients across BMI groups. Impact: This is the largest study in colorectal cancer patients investigating associations of energy balance components with inflammatory biomarkers. Our results suggest that physical activity may reduce obesity-induced inflammation in colorectal cancer patients and support the design of randomized controlled trials testing this hypothesis.

BACKGROUND: Evidence suggests a positive association between sugar intake and colorectal cancer (CRC) outcomes. We sought to investigate inflammation and angiogenesis as underlying mechanisms behind increased sugar intake and worse CRC outcomes. METHOD: Pre-surgery serum samples were obtained from 191 patients diagnosed with primary invasive stage I-IV CRC. Biomarkers of inflammation (CRP, SAA, IL-6, IL-8, MCP-1, TNFα) and angiogenesis (VEGFA, VEGFD, sICAM-1 and sVCAM-1) were analyzed (Meso-Scale-Discovery). Fructose, glucose, sucrose, and total sugar intake (calories/day, % total calories) were assessed by FFQ. Pearson’s correlation and multiple linear regression analyses were performed. RESULTS: Patients were on average 64 years old, 64% were male, the majority was diagnosed with stage II-III (58%) cancers, and 67% were either overweight or obese. Among normalweight individuals (BMI

PURPOSE: A dense breast on mammogram is a strong risk factor for breast cancer. Identifying factors that reduce mammographic breast density could thus provide insight into breast cancer prevention. Due to the limited number of studies and conflicting findings, we investigated the associations of medication use (specifically statins, aspirin, and ibuprofen) with mammographic breast density. METHODS: We evaluated these associations in 775 women who were recruited during an annual screening mammogram at Washington University School of Medicine, St. Louis. We measured mammographic breast density using Volpara. We used multivariable-adjusted linear regressions to determine the associations of medication use (statins, aspirin, and ibuprofen) with mammographic breast density. Least squared means were generated and back-transformed for easier interpretation. RESULTS: The mean age of study participants was 52.9 years. Statin use in the prior 12 months was not associated with volumetric percent density or dense volume, but was positively associated with non-dense volume. The mean volumetric percent density was 8.6% among statin non-users, 7.2% among women who used statins 1–3 days/week, and 7.3% among women who used statins ≥4 days/week (p-trend=0.07). The non-dense volume was 1297.1cm(3) among statin non-users, 1368.7cm(3) among women who used statins 1–3 days/week, and 1408.4cm(3) among those who used statins ≥4 days/week (p-trend=0.02). We did not observe statistically significant differences in mammographic breast density by aspirin or ibuprofen use. CONCLUSION: Statin, aspirin, and ibuprofen use was not associated with volumetric percent density and dense volume, but statin use was positively associated with non-dense volume. Any potential associations of these medications with breast cancer risk are unlikely to be mediated through an effect on volumetric percent density.

Mammographic breast density (MBD) is a risk factor for breast cancer, but its molecular basis is poorly understood. Growth factors stimulate cellular and epithelial proliferation and could influence MBD via these mechanisms. Studies investigating the associations of circulating growth factors with MBD have, however, yielded conflicting results especially in postmenopausal women. We, therefore, investigated the associations of plasma growth factor gene expression [insulin-like growth factor (IGF)-1, IGF-binding protein 3, FGF-1, FGF-12, TGFβ1 and bone morphogenetic protein (BMP)-2] with MBD in postmenopausal women. We used NanoString nCounter platform to quantify plasma growth factor gene expression and Volpara to evaluate volumetric MBD measures. We investigated the associations of growth factor gene expression with MBD using both multiple linear regression (fold change) and multinomial logistic regression models, adjusted for potential confounders. The mean age of the 368 women enrolled was 58 years (range, 50–64). In analyses using linear regression models, one unit increase in IGF-1 gene expression was associated with a 35% higher volumetric percent density (VPD, 1.35; 95% confidence interval (CI), 1.13–1.60; P = 0.001). There were suggestions that TGFβ1 gene expression was positively associated with VPD while BMP-2 gene expression was inversely associated with VPD, but these were not statistically significant. In analyses using multinomial logistic regression, TGFβ1 gene expression was 33% higher (OR = 1.33; 95% CI, 1.13–1.56; P = 0.0008) in women with extremely dense breasts than those with almost entirely fatty breasts. There were no associations between growth factor gene expression and dense volume or nondense volume. Our study provides insights into the associations of growth factors with MBD in postmenopausal women and requires confirmation in other study populations. Prevention Relevance: Mammographic breast density is a strong risk factor for breast cancer. Understanding its underlying biological mechanisms could have utility in breast cancer prevention.

BACKGROUND: Cachexia is a multifactorial metabolic syndrome associated with higher risk of mortality. The precise molecular mechanisms and biological pathways involved remain poorly characterized. A specific criterion of cachexia is loss of muscle mass. Myokines affect muscle mass and have profound effects on glucose and lipid metabolism, thus contributing to energy homeostasis and potentially cachexia. Only sparse data for patients with non-metastatic colorectal cancer exist. This study aims to investigate associations of systemic myokine concentrations with onset of cachexia in non-metastatic colorectal cancer patients. METHODS: Serum samples from n=125 colorectal cancer patients (stage I-III) recruited from the ColoCare Study site at Huntsman Cancer Institute were collected prior to surgery (baseline). Assays were run with the Milliplex Human Myokine Magnetic panel containing beads such as FABP3, Oncostatin M, and FGF21. Patients were defined as cachectic, pre-cachectic, or non-cachectic based on the criteria by Fearon et al. based on sex, BMI, and weight loss over a period of six months. ANOVA were applied to analyze associations of myokines with cachexia at 12 month after surgery, adjusted by age at diagnosis, sex, tumor stage, and tumor site. RESULTS: At the 12 months follow-up, 11% of patients were diagnosed with cachexia (n=14), 14% of patients with pre-cachexia (n=18), and 74% of patients were defined as non-cachectic. Patients with cachexia were more likely to be diagnosed with rectal cancer (57%) compared to pre-cachectic (17%) or non-cachectic patients (42%; p ONCLUSIONS: Cachectic patients presented higher FABP3 concentrations (p=0.02) which were associated with increased risk of cachexia, however these results were not significant after adjustment. In this study, cachectic patients were more likely to be diagnosed with rectal cancer. In summary, larger studies are needed to further evaluate FABP3 and other myokines as potential prognostic biomarkers for cachexia and consider differences by tumor site. Citation Format: Jennifer Ose, Ellen Beswick, Simon Ta Van, Richard H. Viskochil, Christy A. Warby, Jeffrey T. Yap, Matthew F. Covington, Anne H. Nguyen, Jordan W. Stanford, Tengda Lin, Anita R. Peoples, Sheetal Hardikar, Christopher I. Li, William M. Grady, David Shibatta, Adetunji T. Toriola, Martin Schneider, Jane C. Figueiredo, Daniel Jeong, Erin M. Siegel, Cornelia M. Ulrich, Biljana Gigic. Examination of systemic myokine concentrations with risk of cachexia in non-metastatic colorectal cancer patients - Results from the ColoCare Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 355.

Background: Colorectal cancer (CRC) is a complex and heterogeneous disease characterized by distinct molecular features such as RAS and BRAF mutations. Assessing these molecular aberrations provides clinical guidance for selecting and predicting response with therapeutic modalities. Few reports have suggested that patient symptom burden at diagnosis differs across molecular subtypes of CRC. However, the association of RAS and BRAF mutations and symptom burden post-diagnosis in CRC patients has yet to be examined in a prospective cohort. Methods: We assessed CRC patients, stage I-IV, enrolled in the Moffitt ColoCare Study site with clinical molecular testing results and who completed a six-month questionnaire. Tumor mutation (MT) status (RAS/BRAF/Wildtype (WT)) was abstracted from the medical record. The MD Anderson Symptom Inventory (MDASI) was used to assess the severity of 13 cancer-related symptoms on a 1-to-10 scale. Mean scores in mutation subgroups were compared with one-way ANOVA. Linear regression analysis evaluated the association between symptom burden and mutation status. Multivariable regression models were adjusted for age, sex, stage at diagnosis, treatment, and microsatellite instability (MSI). Results: Among the 158 patients, the mean age at diagnosis was 60.9 ± 11.58 years. The prevalence of RAS and BRAF mutations was 30.4% (N=48) and 6.3% (N=10), respectively. Statistically significant mean differences between the mutation subgroups were distress (p=0.005), difficulty remembering (p=0.015), lack of appetite (p=0.042), and sadness (p=0.007). Patients with a BRAF-MT reported significantly more distress (p=0.001), difficulty remembering (p=0.029), and sadness (p=0.002) at six months compared to RAS-MT or RAS/BRAF-WT. Patients with a RAS-MT reported an increased lack of appetite (p=0.038) compared to BRAF-MT or RAS/BRAF-WT. Patients with a BRAF-MT reported higher severity of symptoms interfering with the enjoyment of life (p Conclusions: Tumors with BRAF-MT are molecularly classified into the serrated pathway, which has distinct clinical characteristics and risk factor profile. In this study, patients with tumors harboring BRAF-MT reported a higher symptom burden six months post-diagnosis than those with RAS-MT or RAS/BRAF-WT tumors. While the prevalence of BRAF-MT was low in this population, these findings warrant further investigation in a larger cohort. Citation Format: Gazelle Rouhani, Amanda M. Bloomer, Maria F. Gomez, Gillian K. Trujillo, Devon N. Conant, Seth I. Felder, Cornelia M. Ulrich, Christopher I. Li, Jane C. Figueiredo, Adetunji T. Toriola, Biljana Gigic, Martin Schneider, David Shibata, Erin M. Siegel. Profiling symptom burden of RAS and BRAF mutations in patients with colorectal cancer: Results from the ColoCare Study. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4205.

Introduction: High mammographic breast density (MBD) is a risk factor for breast cancer. Studies are evaluating the associations of various multi-omic biomarkers, in well-defined pathways with MBD, but the existing methodological approaches have drawbacks. For example, multivariate association analysis adjusting for covariates may identify too many biomarkers and lacks proper biological interpretation. On the other hand, simple amalgams (e.g., combination or sum) of species within pathways may result in few associated pathways, as the species within a pathway could have different directions of associations. Variable selection approaches such as the least absolute shrinkage and selection operator (Lasso) select individual species without considering prior knowledge of the pathway structure. We propose a new pathway-guided amalgamation method to form species clusters that could enhance biological interpretation. Methods: The plasma concentration of 982 lipid species in 14 super-pathways was measured in the blood samples of 705 premenopausal women drawn during their annual screening mammogram. We aimed to identify amalgams of lipid species that are associated with the volumetric percent density (VPD, in log scale). The proposed method utilizes the fused Lasso algorithm which penalizes the differences between effects for the lipid species within the same pathway and hence induces equality among similar effects. The lipid species with the same effects can be amalgamated to form clusters of species as new biomarkers. The number of clusters was chosen by cross-validation. Besides amalgamation, the method also facilitates variable selection by singling out influential individual species. Results: The proposed method identified 11 amalgams formed by 744 species, with 3 amalgams in Cholesteryl Esters (CE), and 1 amalgam each in Phosphatidylcholines (PC), Lysophosphatidylcholines (LPC), Phosphatidylinositols (PI), Dihydroceramides (DCER), Hexosylceramides (HCER), Lactosylceramides(LCER), Diacylglycerols (DAG), and Triacylglycerols (TAG). Amalgams in the same pathway can have opposite directions of association: 2 of the 3 amalgams in CE had negative associations with VPD while the third showed a positive association. Species with small effects in the same direction of associations may be combined: an amalgam comprising 518 species in the TAG pathway was identified with each presenting a small negative association with VPD but collectively, forming one amalgam with a large effect. Conclusions: The proposed amalgamation method provides a flexible and interpretable variable selection and clustering approach to discover lipidomic biomarkers for MBD. The amalgamation is especially preferred when multiple biomarkers species within one pathway share similar effects, or species within one pathway show opposite directions of associations. Citation Format: Chongliang Luo, Jingqin Luo, Kayla R. Getz, Myung Sik Jeon, Adetunji T. Toriola. A new methodological approach to discovering biomarkers of mammographic breast density using pathway-guided lipid amalgamation. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4271.

PURPOSE: Fatalism is defined by feelings of pessimism, hopelessness, and powerlessness regarding cancer outcomes. Early researchers reported associations between race and cancer fatalism. Yet current evidence suggests that social determinants of health are better predictors of cancer fatalism than race. Therefore, the aim of this study was to examine the association between age, race, education, and cancer fatalism. METHODS: Three hundred ninety (n=390) women who attended a screening mammogram at the Joanne Knight Breast Health Center, at Siteman Cancer Center at Washington University School of Medicine (St. Louis, MO) completed the Powe Fatalism Inventory (PFI), a 15-item self-report instrument used to operationalize cancer fatalism. We used Pearson’s correlation, independent samples t-tests, one-way ANOVA with post-hoc tests, and linear regression to analyze the relationships between PFI total scores and age, race, and education. RESULTS: There were no differences between the mean PFI scores for Non-Hispanic Whites (1.89, SD 0.55) and African Americans (2.02, SD 0.76, p=0.092, 95%CI-0.27 to 0.02). We found significant differences between the mean PFI scores across levels of education. Women who attained a high school degree or less (n=72) reported higher PFI scores (2.24, SD 0.77) than women who attended some college or post high school vocational training (n=111; 1.95, SD 0.61) and women with a college or postgraduate degree (n=206; 1.83, SD 0.57). When PFI score was regressed onto age, race, and education, only education significantly explained fatalism (B=−0.19, p

The COVID-19 pandemic has disrupted many facets of life. We evaluated pandemic-related health care experiences, COVID-19 prevention behaviors and measures, health behaviors, and psychosocial outcomes among rural and urban cancer patients.Among 1,472 adult cancer patients, who visited Huntsman Cancer Institute in the past 4 years and completed a COVID-19 survey (August-September 2020), we assessed the impact of the pandemic on medical appointments, prevention/health behaviors, and psychosocial factors, stratified by urbanicity.Mean age was 61 years, with 52% female, 97% non-Hispanic White, and 27% were residing in rural areas. Rural versus urban patients were more likely to be older, not employed, uninsured, former/current smokers, consume alcohol, and have pandemic-related changes/cancellations in surgery appointments (all P.05). Changes/cancellations in other health care access (eg, doctor's visits) were also common, particularly among urban patients. Urban versus rural patients were more likely to socially distance, use masks and hand sanitizer, and experience changes in exercise habits and in their daily lives (all P.05). Less social interaction and financial stress were common among cancer patients but did not differ by urbanicity.These findings suggest that the COVID-19 pandemic had a substantial impact on cancer patients, with several challenges specific to rural patients. This comprehensive study provides unique insights into the first 6 months of COVID-19 pandemic-related experiences and continuity of care among rural and urban cancer patients predominantly from Utah. Further research is needed to better characterize the pandemic's short- and long-term effects on rural and urban cancer patients and appropriate interventions.

Family history of breast cancer (FHBC) and mammographic breast density are independent risk factors for breast cancer, but the association of FHBC and mammographic breast density in premenopausal women is not well understood.To investigate the association of FHBC and mammographic breast density in premenopausal women using both quantitative and qualitative measurements.This single-center cohort study examined 2 retrospective cohorts: a discovery set of 375 premenopausal women and a validation set of 14 040 premenopausal women. Data from women in the discovery set was collected between December 2015 and October 2016, whereas data from women in the validation set was collected between June 2010 and December 2015. Data analysis was performed between June 2018 and June 2020.Family history of breast cancer (FHBC).The primary outcomes were mammographic breast density measured quantitatively as volumetric percent density using Volpara (discovery set) and qualitatively using BI-RADS (Breast Imaging Reporting and Data System) breast density (validation set). Multivariable regressions were performed using a log-transformed normal distribution for the discovery set and a logistic distribution for the validation set.Of 14 415 premenopausal women included in the study, the discovery set and validation set had similar characteristics (discovery set with FHBC: mean [SD] age, 47.1 [5.6] years; 15 [17.2%] were Black or African American women and 64 [73.6%] were non-Hispanic White women; discovery set with no FHBC: mean [SD] age, 47.7 [4.5] years; 87 [31.6%] were Black or African American women and 178 [64.7%] were non-Hispanic White women; validation set with FHBC: mean [SD] age, 46.8 [7.3] years; 720 [33.4%] were Black or African American women and 1378 [64.0%] were non-Hispanic White women]; validation set with no FHBC: mean [SD] age, 47.5 [6.1] years; 4572 [38.5%] were Black or African American women and 6632 [55.8%] were non-Hispanic White women]). In the discovery set, participants who had FHBC were more likely to have a higher mean volumetric percent density compared with participants with no FHBC (11.1% vs 9.0%). In the multivariable-adjusted model, volumetric percent density was 25% higher (odds ratio [OR], 1.25 ;95% CI, 1.12-1.41) in women with FHBC compared with women without FHBC; and 24% higher (OR, 1.24; 95% CI, 1.10-1.40) in women who had 1 affected relative, but not significantly higher in women who had at least 2 affected relatives (OR, 1.40; 95% CI, 0.95-2.07) compared with women with no relatives affected. In the validation set, women with a positive FHBC were more likely to have dense breasts (BI-RADS 3-4) compared with women with no FHBC (BI-RADS 3: 41.1% vs 38.8%; BI-RADS 4: 10.5% vs 7.7%). In the multivariable-adjusted model, the odds of having dense breasts (BI-RADS 3-4) were 30% higher (OR, 1.30; 95% CI, 1.17-1.45) in women with FHBC compared with women without FHBC; and 29% higher (OR, 1.29; 95% CI, 1.14-1.45) in women who had 1 affected relative, but not significantly higher in women who had at least 2 affected relatives (OR, 1.38; 95% CI, 0.85-2.23) compared with women with no relatives affected.In this cohort study, having an FHBC was positively associated with mammographic breast density in premenopausal women. Our findings highlight the heritable component of mammographic breast density and underscore the need to begin annual screening early in premenopausal women with a family history of breast cancer.

PURPOSE: Cancer-related distress is known to persist long after completion of treatment. Factors related to distress are largely unexplored in colorectal cancer (CRC) survivors. We examined changes over time and risk factors for distress in CRC patients over the first year after surgery. METHODS: We included 212 CRC patients with data at 6 and 12 months post-surgery from the ColoCare Study in Heidelberg, Germany. Sociodemographic and lifestyle factors, social support and health-related quality of life (HrQOL) prior to surgery were evaluated as predictors of cancer-related distress. Distress was measured with the Cancer and Treatment Distress instrument (CTXD). Linear regression analyses examined associations between risk factors and distress. RESULTS: Distress subscale scores varied significantly over time: health burden subscale score increased (P < .001), while finances (P = .004), medical demands (P < .001), and identity (P < .001) subscale scores decreased over time. Uncertainty and family strain subscale scores did not change. Younger age, lower income, advanced tumor stage, poorer social support, and poorer baseline HrQOL predicted higher level distress at 6 and 12 months. CONCLUSIONS: Cancer-related distress continues unresolved after surgery. Although some risk factors are difficult to alter, those at highest risk can be identified earlier for possible preventive strategies. IMPLICATIONS FOR CANCER SURVIVORS: Screening for risk factors pre-surgery would allow for targeted interventions including strategies to improve resources for those with low support, thereby reducing long-term distress in CRC survivors.

Background: Mammographic breast density is one of the strongest risk factors for breast cancer. Hence, identifying factors that can reduce mammographic breast density could have utility in breast cancer prevention. A few studies have evaluated the associations of statin use and mammographic breast density, with conflicting results. We, therefore, investigated the associations of statin use with mammographic breast density, and further determined the impact of menopausal status on these associations. Methods: We evaluated associations in 635 women recruited during annual screening mammogram at the Joanne Knight Breast Health Centre at Siteman Cancer Centre at Washington University School of Medicine, St. Louis, MO, who provided detailed information on many lifestyle factors, including statin use in the past 12 months and had data on mammographic breast density. We evaluated mammographic breast density using Volpara, which provides volumetric measures. Mammographic breast density measures were log10 transformed for conformity to normality. We used linear regression models, adjusted for confounders (age, body mass index (BMI), race, family history of breast cancer, age at first birth and parity, age at menarche and current alcohol intake) to determine the associations between the statin use and mammographic breast density. Least squared means were generated, and back-transformed for easier interpretation. Results: The mean age of study participants was 52.3 years. Fifty (7.8%) of the 635 women were statin users. The mean BMI among statin users was 31.9kg/m2 vs. 30.5kg/m2 among non-users. After adjusting for confounders, the mean volumetric percent density was lower among statin users (7.6%) than non-users (8.9%), but this was not statistically significant (p-value=0.09). Among premenopausal women, the mean volumetric percent density was 8.3% among statin users vs. 10.3% among non-users (p-value=0.06). Among postmenopausal women, the mean volumetric percent density was 5.2% among statin users vs. 6.4% among non-users (p-value=0.37). On the other hand, non-dense volume was higher among statin users (1519.6 cm3) than non-users (1410.5 cm3; p-value= 0.03). Conclusion: Statin use was associated with higher non-dense volume but appears to be weakly associated with lower volumetric percent density. The association with volumetric percent density was limited to premenopausal women. Findings require confirmation in other studies. Table 1 Associations of statin use (in the past 12 months) with volumetric percent density in 635 women attending annual screening mammogram at the Joanne Knight Breast Health Centre, at Siteman Cancer Centre at Washington University School of Medicine, St. Louis, MO.Statin useNumberLeast square meansP-valueP-trendNon-user5858.9ReferenceUser507.60.09Frequency0.07Non-user5858.9Reference1-3 days187.50.544+ days327.60.09 Model adjusted for family history of breast cancer in a first-degree relative (no, yes, and unknown), race (Non-Hispanic White, Black/African American, Others), age at menarche (continuous) current alcohol intake (no, yes), parity (0, 1, 2, ≥3) and age at first birth (continuous). Frequency: The frequency of statin use, total days per week. Citation Format: Chee Teik Lee, Xiaoyue Mi, Courtnie R. Phillip, Adetunji T. Toriola. Statin use and mammographic breast density [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-08-17.

Background: Mammographic breast density (MBD) is a strong modifiable risk factor for breast cancer, especially in premenopausal women. It is estimated that up to 39% of breast cancer cases in premenopausal women could potentially be prevented by reducing dense breasts to non-dense breasts. Therefore, reducing breast density through targeted interventions is an excellent opportunity to substantially reduce breast cancer incidence in premenopausal women. We performed a critical evaluation of the literature to determine the associations of chemoprevention agents use with MBD. This will guide the management of premenopausal women at risk for breast cancer. Methods: Eleven databases were searched on July 2019. We included interventional, cross-sectional, longitudinal or observational studies in Englishreporting the associations of medication with mammographic breast density in premenopausal womenwith no history of breast cancer. Two researchers extracted the data and assessed the quality of the studies. Supplements not otherwise specified were excluded. Results: After de-duplication process, 1,464 citations were screened for eligibility. Seven studies met our inclusion criteria: two observational, four randomized controlled, and one non-randomized controlled trials (RCT). There were two categories of medications: dietary supplements (i.e. vitamin D, calcium, isoflavone) and drugs (non-steroidal anti-inflammatory drugs [NSAIDs], selective estrogen receptor modulators (SERMs) goserelin, and GnRHA deslorelin acetate). In observational studies, calcium use was associated with a significant reduction in MBD, while vitamin D and NSAIDs showed no reduction6. Likewise, Isoflavone and vitamin D in doses of 1000, 2000 or 3,000IU/day were not associated with a reduction in MBD in two different RCT. Groselin, GnRHA, deslorein acetate, statins were not associated with MBD reduction in an RCT’s. SERMs (tamoxifene and raloxifene) were the only drugs associated with reductions in MBD in RCTs. Conclusions: Only a very limited number of medications (SERMs) are associated with reductions in MBD. In view of their low uptake and adherence, identifying other medications that can reduce MBD is crucial, as these could have utility in breast cancer prevention. Citation Format: Ana S. Salazar, Malika Rakhmankulova, Laura E. Simmon, Adetunji Toriola. Medication use to reduce mammographic breast density in premenopausal women: A systematic review [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-71.

Background: The effect of metformin use on survival among patients with pancreatic ductal adenocarcinoma (PDAC) is controversial. Furthermore, there are no data on African American patients. To address these, we analyzed data from the United States Veterans Health Administration (VHA). Methods: A population-based retrospective cohort study evaluating overall survival among 3,811 patients with PDAC with preexisting diabetes mellitus, diagnosed with PDAC within the VHA between 1998 and 2013. We calculated HRs and 95% confidence intervals (CI) using multivariable adjusted time-varying Cox proportional hazards regression to control for immortal time bias and confounders. Results: Metformin use was not associated with overall survival in the complete analyses (HR = 1.05; 95% CI, 0.92–1.14; P = 0.28). However, among patients who were metformin naïve at the time of PDAC diagnosis (N = 1,158), metformin use was associated with improved overall survival in non-Hispanic white patients (HR = 0.78; 95% CI, 0.61–0.99; P = 0.04), but not African American patients (HR = 1.20; 95% CI, 0.75–1.93; P = 0.45). The survival benefit among non-Hispanic whites was limited to patients with metastatic disease (HR = 0.67; 95% CI, 0.44–1.01; P = 0.06). Among African American patients with metastatic disease, HR was 1.30 (95% CI, 0.77–2.53; P = 0.28). There was a suggestion of heterogeneity by race in patients with metastatic disease (Pheterogeneity = 0.05). Conclusions: We observed no associations between metformin use and survival in patients with PDAC, but there appears to be a survival benefit among non-Hispanic white patients who were metformin naïve at the time of PDAC diagnosis. Impact: If confirmed in other studies, our findings suggest that metformin as an adjunctive treatment for PDAC may not improve survival among African American patients.

Studies have investigated the associations of coffee and tea with mammographic breast density (MBD) in premenopausal women with inconsistent results. We analyzed data from 375 premenopausal women who attended a screening mammogram at Washington University School of Medicine, St. Louis, MO in 2016, and stratified the analyses by race (non-Hispanic White (NHW) vs. Black/African American). Participants self-reported the number of servings of coffee, caffeinated tea, and decaffeinated tea they consumed. Volpara software was used to determine volumetric percent density (VPD), dense volume (DV), and non-dense volume (NDV). We used generalized linear regression models to quantify the associations of coffee and tea intake with MBD measures. Coffee: ≥1 time/day (β = 1.06, 95% CI = 0.93–1.21, p-trend = 0.61) and caffeinated tea: ≥1 time/day (β = 1.01, 95% CI = 0.88–1.17, p-trend = 0.61) were not associated with VPD. Decaffeinated tea (≥1 time/week) was positively associated with VPD in NHW women (β = 1.22, 95% CI = 1.06–1.39) but not in African American women (β = 0.93, 95% CI = 0.73–1.17, p-interaction = 0.02). Coffee (≥1 time/day) was positively associated with DV in African American women (β = 1.52, 95% CI = 1.11–2.07) but not in NHW women (β = 1.10, 95% CI = 0.95–1.29, p-interaction = 0.02). Our findings do not support associations of coffee and caffeinated tea intake with VPD in premenopausal women. Positive associations of decaffeinated tea with VPD, with suggestions of effect modification by race, require confirmation in larger studies with diverse study populations.