Objectives To evaluate pathologic findings and access risk factors in premenopausal patients with hormone receptor-positive metastatic breast cancer undergoing bilateral salpingo-oophorectomy (BSO) for hormone supression.

Methods We retrospectively analyzed data of 170 premenopausal patients with hormone receptor-positive metastatic breast cancer who had been submitted to BSO for ovarian supression between 2009 and 2021 at a terciary hospital in São Paulo, Brazil. All patients were metastatic at the time of surgery, but none had known ovarian metastasis. Patients with preoperative suspicion for malignancy in ovaries were not included. The following characteristics were analyzed: age, BMI, histological type, molecular subtype, HER2 status, initial TNM staging, sites of distant metastases at surgery, number of sites of distant metastases at surgery and the family history of cancer.

Results A total of 170 patients were included. The characteristics of the studied patients are described in table 1. Unknown ovarian metastases of breast cancer were found in 40 patients (23,5%). Multivariate analyses revealed that younger ages (OR, 0.94; 95% CI, 0.88 to 0.99; p=0.04) and the number of sites of metastasis at surgery (≥ 3 sites; OR, 3.99; 95% CI, 1.37 to 11.59; p=0.01) were significantly related with breast cancer ovarian metastases. The remaining studied characteristics were not statistically significant.

Conclusions Younger ages and having 3 or more sites of metastases at surgery appears to be risk factors for ovarian implants in previously metastatic breast cancer patients.