Journal Article

The contribution of pathogenic variants in breast cancer susceptibility genes to familial breast cancer risk

Domchek, Susan M., Ravichandran, Vignesh, Schrader, Kasmintan A., Bonanni, Bernardo, Offit, Kenneth, Szabo, Csilla, Maria, Ann, Vijai, Joseph, D’Andrea, Kurt, Wenz, Brandon M., Neuhausen, Susan L., Thomas, Tinu, Peterlongo, Paolo, Villano, Danylo, Wubbenhorst, Bradley, Lilyquist, Jenna, Ford, James M., Hart, Steven N., Moore, Raymond, Slavin, Thomas P., Couch, Fergus J., Maxwell, Kara N., Garber, Judy E., Nathanson, Katherine L., Weitzel, Jeffrey N., Hu, Chunling, Robson, Mark E.

2017

Overview

Understanding the gene-specific risks for development of breast cancer will lead to improved clinical care for those carrying germline mutations in cancer predisposition genes. We sought to detail the spectrum of mutations and refine risk estimates for known and proposed breast cancer susceptibility genes. Targeted massively-parallel sequencing was performed to identify mutations and copy number variants in 26 known or proposed breast cancer susceptibility genes in 2134 BRCA1/2- negative women with familial breast cancer (proband with breast cancer and a family history of breast or ovarian cancer) from a largely European–Caucasian multi-institutional cohort. Case–control analysis was performed comparing the frequency of internally classified mutations identified in familial breast cancer women to Exome Aggregation Consortium controls. Mutations were identified in 8.2% of familial breast cancer women, including mutations in high-risk (odds ratio > 5) (1.4%) and moderate-risk genes (2 < odds ratio < 5) (2.9%). The remaining familial breast cancer women had mutations in proposed breast cancer genes (1.7%), Lynch syndrome genes (0.5%), and six cases had two mutations (0.3%). Case–control analysis demonstrated associations with familial breast cancer for ATM, PALB2 , and TP53 mutations (odds ratio > 3.0, p  < 10 −4 ), BARD1 mutations (odds ratio = 3.2, p  = 0.012), and CHEK2 truncating mutations (odds ratio  =  1.6, p  = 0.041). Our results demonstrate that approximately 4.7% of BRCA1/2 negative familial breast cancer women have mutations in genes statistically associated with breast cancer. We classified PALB2 and TP53 as high-risk, ATM and BARD1 as moderate risk, and CHEK2 truncating mutations as low risk breast cancer predisposition genes. This study demonstrates that large case–control studies are needed to fully evaluate the breast cancer risks associated with mutations in moderate-risk and proposed susceptibility genes. Familial breast cancer: Pinning down susceptibility genes beyond BRCA Women with the heritable form of breast cancer often harbor mutations in cancer-linked genes other than the usual suspects, BRCA1 and BRCA2 . Slavin, Maxwell, Lilyquist, Joseph, and colleagues from major national and international cancer centers studied 2134 women with familial breast cancer who tested negative for BRCA1/2 gene mutations. The researchers sequenced 26 known or proposed breast cancer susceptibility genes and found mutations in approximately 1 in every 12 of the study subjects. They then further broke down the susceptibility genes into those that confer high-, moderate- or low-risk—although not all the proposed breast cancer genes reached statistical significance and, as such, their clinical importance remains unclear. The results support adding some of the high- and moderate-risk genes to multi-panel diagnostic tests that aim to determine the likelihood of a women developing heritable breast cancer.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 692/308/2056 / 692/4028/67/68 / Biomedical and Life Sciences / Biomedicine / Breast cancer / Cancer Research / Cell Biology / Colorectal cancer / Genetic disorders / Health risk assessment / Human Genetics / Mammography / Mutation / Oncology / Ovarian cancer