BRCA1/2 mutation carriers vs the general breast cancer population (N = 799,986): 21-gene assay-based molecular characterization.

PURPOSE: We compared 21-gene recurrence score (RS) distribution and expression of the single-gene/gene groups within this assay between BC patients with pathogenic variants (PV) in BRCA1/2 vs the general 21-gene-tested BC population. METHODS: This retrospective study included consecutive 21-gene-tested female ER + HER2-negative BC patients with germline PVs in BRCA1/2. RS/gene expression data were compared to a previously described commercial use database (CDB, N = 799,986). Chi-square and 1-sample t test were used to compare RS distribution and single-gene/gene group scores between the study group and the CDB. RESULTS: Study group patients (N = 81) were younger and their RS results were higher compared to the CDB (age: median [IQR], 56 [47-61.5] vs 60 [51-67] years; p < 0.001; proportion of patients with RS ≥ 26: 49.4% vs 16.4%, p < 0.001). Expression of 12/16 cancer genes in the assay and the ER, proliferation, and invasion gene group scores differed significantly between the study group and the CDB, all in a direction contributing to higher RS. The differences between the study group and the CDB were mostly retained, upon stratifying the patients by menopausal status. CONCLUSION: BC patients with PVs in BRCA1/2 have higher RS results that stem from distinct gene expression profiles in the majority of genes in the 21-gene assay.

Rate of breast biopsy referrals in female BRCA mutation carriers aged 50 years or more: a retrospective comparative study and matched analysis.

PURPOSE: To evaluate the total biopsy and positive biopsy rates in women at high risk of breast cancer compared to the general population. METHODS: The study group consisted of 330 women with pathogenic variants (PVs) in BRCA1/2 attending the dedicated multidisciplinary breast cancer clinic of a tertiary medical center in Israel. Clinical, genetic, and biopsy data were retrieved from the central healthcare database and the medical files. Patients aged 50 years or older during follow-up were matched 1:10 to women in the general population referred for routine breast cancer screening at the same age, as recommended by international guidelines. The groups were compared for rate of biopsy studies performed and percentage of positive biopsy results. Matched analysis was performed to correct for confounders. RESULTS: The total biopsy rate per 1000 follow-up years was 61.7 in the study group and 22.7 in the control group (p < 0.001). The corresponding positive biopsy rates per 1000 follow-up years were 26.4 and 2.0 (p < 0.001), and the positive biopsy percentages, 42.9% and 8.7% (p < 0.0001). CONCLUSION: Women aged 50 + years with PVs in BRCA1/2 attending a dedicated clinic have a 2.7 times higher biopsy rate per 1000 follow-up years, a 13.2 times higher positive biopsy rate per 1000 follow-up years, and a 4.9 times higher positive biopsy percentage than same-aged women in the general population.

3,3-Diindolylmethane (DIM): a nutritional intervention and its impact on breast density in healthy BRCA carriers. A prospective clinical trial.

Women who carry the BRCA mutation are at high lifetime risk of breast cancer, but there is no consensus regarding an effective and safe chemoprevention strategy. A large body of evidence suggests that 3,3-diindolylmethane (DIM), a dimer of indole-3-carbinol found in cruciferous vegetables, can potentially prevent carcinogenesis and tumor development. The primary aim of this prospective single-arm study was to investigate the effect of DIM supplementation on breast density, a recognized predictive factor of breast cancer risk. Participants were 23 healthy female BRCA carriers (median age 47 years; 78% postmenopausal) who were treated with oral DIM 100 mg × 1/day for 1 year. The amount of fibroglandular tissue (FGT) and background parenchymal enhancement (BPE) on magnetic resonance imaging (MRI) performed before and after the intervention was scored by two independent expert radiologists using the Breast Imaging and Reporting Data System. The results showed a decrease in the average score for FGT amount from 2.8 ± 0.8 at the onset to 2.65 ± 0.84 after 1 year (P = 0.031), with no significant change in BPE (P = 0.429). A group of DIM-untreated age- and menopausal-status-matched women from the BRCA clinic did not show a significant change in FGT amount (P = 0.33) or BPE (P = 0.814) in a parallel year. Mean estradiol level decreased from 159 to 102 pmol/l (P = 0.01), and mean testosterone level decreased from 0.42 to 0.31 pmol/l (P = 0.007). Side effects were grade 1. In conclusion, 1 year's supplementation with DIM 100 mg × 1/day in BRCA carriers was associated with a significant decline in FGT amount on MRI. Larger randomized studies are warranted to corroborate these findings.