There is a paucity of information on the prevalence of dietary supplement use in breast cancer survivors. Only a few studies have examined the impact of dietary supplements, particularly antioxidants, on breast cancer prognosis and the results are inconclusive. We examined pre- and postdiagnosis use of supplements in postmenopausal breast cancer survivors in Germany and investigated associations between postdiagnosis use of antioxidants and other supplements, and prognosis (total and breast cancer mortality, and recurrence-free survival) both overall and in women who received chemotherapy and radiation therapy. Data from 2223 postmenopausal women diagnosed with nonmetastatic breast cancer from the population-based Mamma Carcinoma Risk Factor Investigation (MARIE) study were used. Women were interviewed at recruitment in 2002-2005 and again in 2009 and followed-up until 30 June 2015. Multivariate Cox regression analysis was used to estimate HRs and corresponding 95% CIs. Pre- and postdiagnosis supplement use was reported by 36% and 45% of the women, respectively. There were 240 deaths (134 from breast cancer) and 200 breast cancer recurrences after a median follow-up time of 6.0 y after the 2009 re-interview. After adjusting for relevant confounders, concurrent antioxidant use with chemotherapy or radiation therapy among 1940 women was associated with increased risk of total mortality (HR: 1.64; 95% CI: 1.01, 2.66) and worsened recurrence-free survival (HR: 1.84; 95% CI: 1.26, 2.68). Overall postdiagnosis supplement use was not associated with breast cancer prognosis. Antioxidant use during chemotherapy or radiation therapy was associated with worsened breast cancer prognosis in postmenopausal women. There was no overall association between postdiagnosis supplement use and breast cancer prognosis. Results from our study align with the current recommendation to possibly avoid the use of antioxidants during chemotherapy or radiation therapy.

Purpose: Gene expression–based molecular subtypes of high-grade serous tubo-ovarian cancer (HGSOC), demonstrated across multiple studies, may provide improved stratification for molecularly targeted trials. However, evaluation of clinical utility has been hindered by nonstandardized methods, which are not applicable in a clinical setting. We sought to generate a clinical grade minimal gene set assay for classification of individual tumor specimens into HGSOC subtypes and confirm previously reported subtype-associated features. Experimental Design: Adopting two independent approaches, we derived and internally validated algorithms for subtype prediction using published gene expression data from 1,650 tumors. We applied resulting models to NanoString data on 3,829 HGSOCs from the Ovarian Tumor Tissue Analysis consortium. We further developed, confirmed, and validated a reduced, minimal gene set predictor, with methods suitable for a single-patient setting. Results: Gene expression data were used to derive the predictor of high-grade serous ovarian carcinoma molecular subtype (PrOTYPE) assay. We established a de facto standard as a consensus of two parallel approaches. PrOTYPE subtypes are significantly associated with age, stage, residual disease, tumor-infiltrating lymphocytes, and outcome. The locked-down clinical grade PrOTYPE test includes a model with 55 genes that predicted gene expression subtype with >95% accuracy that was maintained in all analytic and biological validations. Conclusions: We validated the PrOTYPE assay following the Institute of Medicine guidelines for the development of omics-based tests. This fully defined and locked-down clinical grade assay will enable trial design with molecular subtype stratification and allow for objective assessment of the predictive value of HGSOC molecular subtypes in precision medicine applications. See related commentary by McMullen et al., p. 5271

Linkage and candidate gene studies have identified several breast cancer susceptibility genes, but the overall contribution of coding variation to breast cancer is unclear. To evaluate the role of rare coding variants more comprehensively, we performed a meta-analysis across three large whole-exome sequencing datasets, containing 26,368 female cases and 217,673 female controls. Burden tests were performed for protein-truncating and rare missense variants in 15,616 and 18,601 genes, respectively. Associations between protein-truncating variants and breast cancer were identified for the following six genes at exome-wide significance (P < 2.5 × 10⁻⁶): the five known susceptibility genesATM,BRCA1,BRCA2,CHEK2andPALB2, together withMAP3K1. Associations were also observed forLZTR1,ATRIPandBARD1withP < 1 × 10⁻⁴. Associations between predicted deleterious rare missense or protein-truncating variants and breast cancer were additionally identified forCDKN2Aat exome-wide significance. The overall contribution of coding variants in genes beyond the previously known genes is estimated to be small.

We evaluated the joint associations between a new 313-variant PRS (PRS₃₁₃) and questionnaire-based breast cancer risk factors for women of European ancestry, using 72 284 cases and 80 354 controls from the Breast Cancer Association Consortium. Interactions were evaluated using standard logistic regression and a newly developed case-only method for breast cancer risk overall and by estrogen receptor status. After accounting for multiple testing, we did not find evidence that per-standard deviation PRS₃₁₃ odds ratio differed across strata defined by individual risk factors. Goodness-of-fit tests did not reject the assumption of a multiplicative model between PRS₃₁₃ and each risk factor. Variation in projected absolute lifetime risk of breast cancer associated with classical risk factors was greater for women with higher genetic risk (PRS₃₁₃ and family history) and, on average, 17.5% higher in the highest vs lowest deciles of genetic risk. These findings have implications for risk prevention for women at increased risk of breast cancer.

Background: Breast cancer (BC) survivors often suffer from late and long-term residual symptoms of the disease and its treatment. To date, long-term health-related quality of life (HRQoL) in breast cancer survivors has been seldom investigated and rarely compared to unaffected women (controls). Aim: This study aimed to investigate HRQoL over time using patient-reported status before diagnosis, during treatment, 1 year post-surgery, approx. 5 years and ≥10 years post-diagnosis. We also compared survivors’ HRQoL with controls’ still alive 10 years after recruitment. Methods: Data from the German population-based Mamma Carcinoma Risk Factor Investigation (MARIE) cohort of 1123 BC patients aged 50–74 years at diagnosis (2002–2005) and of 3453 matched controls were used for analysis. HRQoL was assessed with the European Organization for Research and Treatment of Cancer (EORTC QLQ-C30) questionnaire. All analyses were conducted for all ages as well as stratified according to three age groups (≤58 years, 59–64 years, ≥64 years). Differences in survivors’ general HRQoL before, during, and after therapy were investigated using a t-test/Wilcoxon signed-rank test. Changes in the HRQoL of survivors stratified by age from FU1 to FU2 were assessed via repeated analysis of variance. The HRQoL of survivors compared to the controls at FU2 was analyzed using an analysis of variance. Results: Over all ages, the general HRQoL in patients improved in the first 5 years post-diagnosis. In the subsequent years, HRQoL slightly deteriorated but was comparable to that of the controls. Younger survivors mostly improved their HRQoL from the 5 to 10-year follow-up but remained negatively affected for most functioning and symptom scales compared to controls. In older survivors, HRQoL hardly changed over time and detriments were less pronounced compared to controls, except for insomnia. Conclusions: Restrictions of HRQoL persist for more than 10 years and are most prominent among younger survivors. Researchers and clinicians should be aware of such potential deteriorations and age-dependent differences in order to optimize/adapt long-term cancer survivor care.

Reproductive factors have been shown to be differentially associated with risk of estrogen receptor (ER)-positive and ER-negative breast cancer. However, their associations with intrinsic-like subtypes are less clear. Analyses included up to 23 353 cases and 71 072 controls pooled from 31 population-based case-control or cohort studies in the Breast Cancer Association Consortium across 16 countries on 4 continents. Polytomous logistic regression was used to estimate the association between reproductive factors and risk of breast cancer by intrinsic-like subtypes (luminal A-like, luminal B-like, luminal B-HER2–like, HER2-enriched–like, and triple-negative breast cancer) and by invasiveness. All statistical tests were 2-sided. Compared with nulliparous women, parous women had a lower risk of luminal A-like, luminal B-like, luminal B-HER2–like, and HER2-enriched–like disease. This association was apparent only after approximately 10 years since last birth and became stronger with increasing time (odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.49 to 0.71; and OR = 0.36, 95% CI = 0.28 to 0.46 for multiparous women with luminal A-like tumors 20 to less than 25 years after last birth and 45 to less than 50 years after last birth, respectively). In contrast, parous women had a higher risk of triple-negative breast cancer right after their last birth (for multiparous women: OR = 3.12, 95% CI = 2.02 to 4.83) that was attenuated with time but persisted for decades (OR = 1.03, 95% CI = 0.79 to 1.34, for multiparous women 25 to less than 30 years after last birth). Older age at first birth (P_{heterogeneity} < .001 for triple-negative compared with luminal A-like breast cancer) and breastfeeding (P_{heterogeneity} < .001 for triple-negative compared with luminal A-like breast cancer) were associated with lower risk of triple-negative breast cancer but not with other disease subtypes. Younger age at menarche was associated with higher risk of all subtypes; older age at menopause was associated with higher risk of luminal A-like but not triple-negative breast cancer. Associations for in situ tumors were similar to luminal A-like. This large and comprehensive study demonstrates a distinct reproductive risk factor profile for triple-negative breast cancer compared with other subtypes, with implications for the understanding of disease etiology and risk prediction.