Search

The transferability and clinical value of genetic risk scores (GRSs) across populations remain limited due to an imbalance in genetic studies across ancestrally diverse populations. Here we conducted a multi-ancestry genome-wide association study of 156,319 prostate cancer cases and 788,443 controls of European, African, Asian and Hispanic men, reflecting a 57% increase in the number of non-European cases over previous prostate cancer genome-wide association studies. We identified 187 novel risk variants for prostate cancer, increasing the total number of risk variants to 451. An externally replicated multi-ancestry GRS was associated with risk that ranged from 1.8 (per standard deviation) in African ancestry men to 2.2 in European ancestry men. The GRS was associated with a greater risk of aggressive versus non-aggressive disease in men of African ancestry (P= 0.03). Our study presents novel prostate cancer susceptibility loci and a GRS with effective risk stratification across ancestry groups.

IMPORTANCE: Germline gene panel testing is recommended for men with advanced prostate cancer (PCa) or a family history of cancer. While evidence is limited for some genes currently included in panel testing, gene panels are also likely to be incomplete and missing genes that influence PCa risk and aggressive disease. OBJECTIVE: To identify genes associated with aggressive PCa. DESIGN, SETTING, AND PARTICIPANTS: A 2-stage exome sequencing case-only genetic association study was conducted including men of European ancestry from 18 international studies. Data analysis was performed from January 2021 to March 2023. Participants were 9185 men with aggressive PCa (including 6033 who died of PCa and 2397 with confirmed metastasis) and 8361 men with nonaggressive PCa. EXPOSURE: Sequencing data were evaluated exome-wide and in a focused investigation of 29 DNA repair pathway and cancer susceptibility genes, many of which are included on gene panels. MAIN OUTCOMES AND MEASURES: The primary study outcomes were aggressive (category T4 or both T3 and Gleason score ≥8 tumors, metastatic PCa, or PCa death) vs nonaggressive PCa (category T1 or T2 and Gleason score ≤6 tumors without known recurrence), and metastatic vs nonaggressive PCa. RESULTS: A total of 17 546 men of European ancestry were included in the analyses; mean (SD) age at diagnosis was 65.1 (9.2) years in patients with aggressive PCa and 63.7 (8.0) years in those with nonaggressive disease. The strongest evidence of association with aggressive or metastatic PCa was noted for rare deleterious variants in known PCa risk genes BRCA2 and ATM (P ≤ 1.9 × 10−6), followed by NBN (P = 1.7 × 10−4). This study found nominal evidence (P < .05) of association with rare deleterious variants in MSH2, XRCC2, and MRE11A. Five other genes had evidence of greater risk (OR≥2) but carrier frequency differences between aggressive and nonaggressive PCa were not statistically significant: TP53, RAD51D, BARD1, GEN1, and SLX4. Deleterious variants in these 11 candidate genes were carried by 2.3% of patients with nonaggressive, 5.6% with aggressive, and 7.0% with metastatic PCa. CONCLUSIONS AND RELEVANCE: The findings of this study provide further support for DNA repair and cancer susceptibility genes to better inform disease management in men with PCa and for extending testing to men with nonaggressive disease, as men carrying deleterious alleles in these genes are likely to develop more advanced disease.

Prostate cancer is a highly heritable disease with large disparities in incidence rates across ancestry populations. We conducted a multiancestry meta-analysis of prostate cancer genome-wide association studies (107,247 cases and 127,006 controls) and identified 86 new genetic risk variants independently associated with prostate cancer risk, bringing the total to 269 known risk variants. The top genetic risk score (GRS) decile was associated with odds ratios that ranged from 5.06 (95% confidence interval (CI), 4.84–5.29) for men of European ancestry to 3.74 (95% CI, 3.36–4.17) for men of African ancestry. Men of African ancestry were estimated to have a mean GRS that was 2.18-times higher (95% CI, 2.14–2.22), and men of East Asian ancestry 0.73-times lower (95% CI, 0.71–0.76), than men of European ancestry. These findings support the role of germline variation contributing to population differences in prostate cancer risk, with the GRS offering an approach for personalized risk prediction.

Increased mammographic density is a strong risk factor for breast cancer. The reasons for this are not clear; two obvious possibilities are increased epithelial cell proliferation in mammographically dense areas and increased breast epithelium in women with mammographically dense breasts. We addressed this question by studying the number of epithelial cells in terminal duct lobular units (TDLUs) and in ducts, and their proliferation rates, as they related to local breast densities defined histologically within individual women. We studied deep breast tissue away from subcutaneous fat obtained from 12 healthy women undergoing reduction mammoplasty. A slide from each specimen was stained with the cell-proliferation marker MIB1. Each slide was divided into (sets of) areas of low, medium and high density of connective tissue (CT; highly correlated with mammographic densities). Within each of the areas, the numbers of epithelial cells in TDLUs and ducts, and the numbers MIB1 positive, were counted. The relative concentration (RC) of epithelial cells in high compared with low CT density areas was 12.3 (95% confidence interval (CI) 10.9 to 13.8) in TDLUs and 34.1 (95% CI 26.9 to 43.2) in ducts. There was a much smaller difference between medium and low CT density areas: RC = 1.4 (95% CI 1.2 to 1.6) in TDLUs and 1.9 (95% CI 1.5 to 2.3) in ducts. The relative mitotic rate (RMR; MIB1 positive) of epithelial cells in high compared with low CT density areas was 0.59 (95% CI 0.53 to 0.66) in TDLUs and 0.65 (95% CI 0.53 to 0.79) in ducts; the figures for the comparison of medium with low CT density areas were 0.58 (95% CI 0.48 to 0.70) in TDLUs and 0.66 (95% CI 0.44 to 0.97) in ducts. Breast epithelial cells are overwhelmingly concentrated in high CT density areas. Their proliferation rate in areas of high and medium CT density is lower than that in low CT density areas. The increased breast cancer risk associated with increased mammographic densities may simply be a reflection of increased epithelial cell numbers. Why epithelium is concentrated in high CT density areas remains to be explained.

The association between soyfood intake and breast cancer risk is controversial. Most of the epidemiologic studies published on this topic in the 1990s were not designed to specifically address this question. We conducted a population-based, case-control study of breast cancer among Chinese, Japanese and Filipino women in Los Angeles County to further investigate the role of soy. Our primary objective was to quantify breast cancer risks associated with intake of soy during adolescence and adult life among Asian-American women. During 1995–1998, we successfully interviewed 501 breast cancer patients and 594 control subjects. Intake of soy among Asian-Americans is still relatively high; the median intake was 12 mg isoflavones/day, approximately one-third of that reported in a recent study in Shanghai, China. The risk of breast cancer was significantly inversely associated with soy intake during adolescence and adult life. After adjusting for age, specific Asian ethnicity, education, migration history and menstrual and reproductive factors, women who reported soy intake at least once per week during adolescence showed a statistically significantly reduced risk of breast cancer. There was also a significant trend of decreasing risk with increasing soy intake during adult life. When we considered soy intake during both adolescence and adult life, subjects who were high-soy consumers during both time periods showed the lowest risk (OR=0.53, 95% CI=0.36–0.78) compared with those who were low consumers during both time periods. Risk of breast cancer was intermediate among subjects who were high-soy consumers during adolescence and low-soy consumers during adult life (OR=0.77, 95% CI=0.51–1.10). Based on a relatively small number of subjects, the risk did not appear to differ between those who were low consumers during adolescence and high consumers during adult life. Results remained similar after adjustment for other potential confounders including other dietary and non-dietary risk factors for breast cancer. These results show that high soy intake in childhood in Asian-Americans is associated with reduced breast cancer risk. Risk may be further reduced by intake as an adult.

The association between soyfood intake and breast cancer risk is controversial. Most of the epidemiologic studies published on this topic in the 1990s were not designed to specifically address this question. We conducted a population-based, case-control study of breast cancer among Chinese, Japanese and Filipino women in Los Angeles County to further investigate the role of soy. Our primary objective was to quantify breast cancer risks associated with intake of soy during adolescence and adult life among Asian-American women. During 1995-1998, we successfully interviewed 501 breast cancer patients and 594 control subjects. Intake of soy among Asian-Americans is still relatively high; the median intake was 12 mg isoflavones/day, approximately one-third of that reported in a recent study in Shanghai, China. The risk of breast cancer was significantly inversely associated with soy intake during adolescence and adult life. After adjusting for age, specific Asian ethnicity, education, migration history and menstrual and reproductive factors, women who reported soy intake at least once per week during adolescence showed a statistically significantly reduced risk of breast cancer. There was also a significant trend of decreasing risk with increasing soy intake during adult life. When we considered soy intake during both adolescence and adult life, subjects who were high-soy consumers during both time periods showed the lowest risk (OR=0.53, 95% CI=0.36-0.78) compared with those who were low consumers during both time periods. Risk of breast cancer was intermediate among subjects who were high-soy consumers during adolescence and low-soy consumers during adult life (OR=0.77, 95% CI=0.51-1.10). Based on a relatively small number of subjects, the risk did not appear to differ between those who were low consumers during adolescence and high consumers during adult life. Results remained similar after adjustment for other potential confounders including other dietary and non-dietary risk factors for breast cancer. These results show that high soy intake in childhood in Asian-Americans is associated with reduced breast cancer risk. Risk may be further reduced by intake as an adult.

Objective: Previous studies have suggested that high levels of galactose consumption and/or low levels of galactose-1-phosphate uridyl transferase (GALT) activity may result in an increased risk of epithelial ovarian cancer. Similarly, some have reported that carriers of the N314D (asparagine at codon 314 replaced by aspartate) GALT polymorphism, which can be associated with low GALT activity, may have a higher risk of ovarian cancer. We examined these issues as part of a large case–control study of ovarian cancer conducted in Los Angeles between 1992 and 1998. Methods: A total of 1439 histologically confirmed borderline and invasive ovarian cancer cases among English-speaking non-Asian women were ascertained through the population-based cancer registry for Los Angeles County and completed in-person interviews were obtained from 689 of these (78% of cases approached). Controls consisted of 645 English-speaking non-Asian women with at least one intact ovary matched to cases on race/ethnicity (African-American, Latina, non-Latina White), date of birth (±3 years), and neighborhood of residence. Interviewer-administered questionnaires included information on reproductive factors, exogenous hormone use, medical history, and diet. Dietary information for the year before each case's diagnosis (and the same period for her matched control) was obtained using a self-administered food-frequency questionnaire. Blood samples were obtained from 452 controls, 136 cases with borderline ovarian cancer, and 312 cases with invasive ovarian cancer. The N314D polymorphism was characterized using PCR-RFLP and GALT enzyme activity, and was determined for a sample of the subjects with GALT genotype using an erythrocyte-based radioactive enzyme assay. Results: We found no effect of N314D GALT genotype on the risk of borderline ovarian cancer (odds ratio (OR) = 0.91; 95% confidence interval (CI) = 0.54–1.6) or invasive ovarian cancer (OR = 0.78; 95% CI & equals; 0.53–1.2). Neither did we observe a relationship between GALT activity or lactose/galactose intake and risk of borderline or invasive ovarian cancer. Among N314D carriers, galactose consumption was associated with an increased risk of borderline (OR = 2.7, p= 0.01), but not invasive (OR = 1.2, p= 0.34), ovarian cancer; however, this result was based on only 24 N314D-positive borderline cases. Conclusions: Differences in galactose intake and GALT metabolism do not contribute significantly to the risk of ovarian cancer. There is some evidence that galactose intake may play a role in the development of borderline ovarian cancer among women who carry the uncommon GALT N314D polymorphism. More data are needed if this latter suggestion is to be definitively addressed.

Objectives: Since the 1970s incidence rates for esophageal and gastric cardia adenocarcinomas have risen substantially, particularly among white males in the United States. Reasons for the increase of these tumor types are not well understood. We sought to determine the role of smoking, alcohol use, and body size characteristics in the etiology of esophageal, gastric cardia, and distal gastric adenocarcinomas. Materials and methods: A population-based case–control study that included Whites, African-Americans, Latinos and Asian-Americans diagnosed with incident esophageal (n = 222), gastric cardia (n = 277), and distal gastric adenocarcinomas (n = 443), and 1356 control subjects was conducted in Los Angeles County. Unconditional logistic regression was used to calculate odds ratios (ORs), as an estimate of the relative risk, and corresponding 95% confidence intervals (CIs) for the three tumor types of interest. Results: After adjustment for age, gender, race, birthplace, and education, current cigarette smoking was a significant risk factor for all tumor types; the association was strongest for esophageal adenocarcinomas (OR = 2.80, 95% CI = 1.8–4.3), intermediate for gastric cardia adenocarcinomas (OR = 2.12, 95% CI = 1.5–3.1), and weaker for distal gastric adenocarcinomas (OR = 1.50, 95% CI = 1.1–2.1). For esophageal adenocarcinomas only, cigarette smoking had a long-lasting deleterious effect, even 20 years after smoking cessation. Alcohol use was not associated with an increased risk of these tumor types. Risks of esophageal and gastric cardia adenocarcinomas also increased statistically significantly in a dose-dependent manner with increasing body mass index measured at ages 20 and 40 years and recently. The positive associations with smoking and body mass index were generally consistent when evaluated separately for Whites, non-Whites, males, and females. Conclusions: Cigarette smoking and high body mass index are significant, independent risk factors for esophageal and gastric cardia adenocarcinomas. Studies designed to understand the mechanisms whereby smoking and high body mass influence these tumor types are needed.

A Correction to this paper has been published: https://doi.org/10.1038/s41588-021-00786-2.

In contrast to the unopposed estrogen used for some time as hormone replacement therapy (HRT) in the United States, combination regimens (CHRT) are becoming increasingly popular. With this approach, a progestin is added to estrogen for either the entire monthly cycle or sequentially. Because reassessment of the relationship between HRT and breast cancer seemed to be in order, a population-based, case-control study was planned. Women diagnosed with incident breast cancer in Los Angeles County were enrolled over a 4.5-year period starting in mid-1987. Cases included 1897 postmenopausal women ranging in age from 55 to 76 years; there were 1637 control women. No subject had undergone simple hysterectomy.