Prognosis of BRCA1/2-negative breast cancer patients with HBOC risk factors compared with sporadic breast cancer patients without HBOC risk factors

Objective: Demands for genetic counseling with BRCA1/2 examination have markedly increased. Accordingly, the incidence of uninformative results on BRCA1/2 mutation status has also increased. Because most patients examined for BRCA1/2 mutation have a high risk of hereditary breast and/or ovarian cancer, many patients suffer psychological distress even when the BRCA1/2 result is negative. We compared oncological outcomes between BRCA1/2-negative breast cancer with high risk of hereditary breast and/or ovarian cancer and sporadic breast cancer without risk of hereditary breast and/or ovarian cancer. Methods: The criteria for high risk for hereditary breast and/or ovarian cancer were defined as family history of breast and/or ovarian cancer in first- or second-degree relative, early onset breast cancer at <35 years old and bilateral breast cancer. Patients were matched maximally 1:3 into those who identified as negative for BRCA1/2 mutation with risk of hereditary breast and/or ovarian cancer (study group) and those who were not examined for BRCA1/2 mutation without risk for hereditary breast and/or ovarian cancer (control group). Matched variables were pathologic stage, estrogen receptor, progesterone receptor and human epidermal growth factor receptor-2 status. Results: All matching variables were successfully matched. Median follow-up duration was 57.8 months. There was no significant difference between the groups in disease-free survival (log-rank P = 0.197); however, the study group showed significantly better overall survival and breast cancer-specific survival (both P < 0.0001). We conducted subgroup analysis in the middle-aged group (36-54) and showed no significant difference for disease-free survival (P = 0.072) but significantly better overall survival and breast cancer-specific survival in the study group (P = 0.002 and P < 0.0001). Conclusions: BRCA1/2-negative breast cancer patients who had hereditary breast and/or ovarian cancer risk factors showed similar disease-free survival and better overall survival and breast cancer-specific survival compared with those with sporadic breast cancer without hereditary breast and/or ovarian cancer risk factors.