A study identifies which women have twice the risk of cancer in both breasts

Women with cancer in one breast may be at increased risk of developing cancer in the opposite breast if they carry specific genetic changes that predispose them to developing breast cancer, a study led by the Mayo Clinic Comprehensive Cancer Center (United States) has shown. Joined).

The findings, published in the Journal of Clinical Oncology, could help personalize breast cancer screening approaches and risk factors, according to the study authors.

The research used data from 15,104 women undergoing prospective follow-up in the CAnceR Risk Estimates Related to Susceptibility (CARRIERS) consortium. The researchers found that patients who carry a germline mutation in BRCA1, BRCA2, or CHEK2 have at least a two-fold increased risk of developing cancer in both breasts, known as contralateral breast cancer.

In contrast, patients carrying germline TMJ mutations did not have a significantly increased risk of contralateral breast cancer. Among PALB2 carriers, the risk of contralateral breast cancer was significantly elevated only among those with estrogen receptor-negative disease.

“These are the first population-based figures that exist for these three genes beyond BRCA1/2. It is also one of the largest studies to provide estimates of contralateral breast cancer risk based on age at diagnosis, menopausal status and race/ethnicity in carriers of germline mutations,” said Fergus Couch, the study’s principal investigator.

Most breast cancer patients who carry germline mutations assume that they are at high risk of developing cancer in the contralateral breast. While this is true for BRCA1/2 mutation carriers with breast cancer, the risk of contralateral breast cancer in carriers of the ATM, CHEK2, or PALB2 germline mutation has not been previously established.

Even for BRCA1/2 carriers, a comprehensive assessment of contralateral breast cancer risk based on age, estrogen receptor status, menopausal status, and the effect of breast cancer treatment has not been performed. initial.

The researchers found that premenopausal women who carry germline mutations are generally at higher risk of contralateral breast cancer than postmenopausal women at diagnosis.

Among women with germline mutations in breast cancer predisposition genes, black and non-Hispanic white women have a similar elevated risk of contralateral breast cancer, according to the study, suggesting that risk management strategies should be Similar.

“Many women undergo a bilateral mastectomy to reduce the chance of a second breast cancer. We now have data to work with when making the decision to remove the second breast, pursue aggressive surveillance, or take preventative medication.” has riveted Couch.