Risk for Contralateral Breast Cancer Higher for Certain Pathogenic Variant Carriers

FRIDAY, Feb. 3, 2023 (HealthDay News) — Women diagnosed with breast cancer who carry germline pathogenic variants (PVs) in BRCA1, BRCA2, CHEK2, and PALB2 have an elevated risk for contralateral breast cancer (CBC), according to a study published online Jan. 9 in the Journal of Clinical Oncology.

Siddhartha Yadav, M.D., from the Mayo Clinic in Rochester, Minnesota, and colleagues prospectively followed 15,104 women treated with ipsilateral surgery for invasive breast cancer. The risk for CBC was estimated for women with versus those without PVs in ATM, BRCA1, BRCA2, CHEK2, and PALB2.

The researchers found that CBC risk was significantly elevated for germline BRCA1, BRCA2, and CHEK2 PV carriers with breast cancer (hazard ratios >1.9), while elevated risk was only seen for PALB2 carriers with estrogen receptor (ER)-negative breast cancer (hazard ratio, 2.9). No significant increased risk for CBC was seen for ATM carriers. Similarly elevated risks for CBC were seen for African American and non-Hispanic White PV carriers. The 10-year cumulative incidence of CBC among premenopausal women was estimated at 33, 27, and 13 percent for BRCA1, BRCA2, and CHEK2 PV carriers with breast cancer and 35 percent for PALB2 carriers with ER-negative breast cancer. Among postmenopausal PV carriers, the 10-year cumulative incidence of CBC was 12, 9, and 4 percent for BRCA1, BRCA2, and CHEK2.

“This study provides clinically meaningful guidance for surveillance and risk reduction strategies for CBC risk among breast cancer survivors who are carriers of PVs in breast cancer predisposition genes,” the authors write.

Several authors disclosed ties to the biopharmaceutical and medical device industries.