Ovarian Cancer Spreads to the Breast During Platinum-Resistant Recurrence

What happened, in summary

A 59-year-old woman presented with abdominal pain, bloating, and constipation and was diagnosed with Stage III high-grade serous ovarian cancer. She received 4 cycles of carboplatin and paclitaxel, followed by extensive cytoreductive surgery that left no visible residual disease. Three more chemotherapy cycles and niraparib maintenance followed. Testing showed no BRCA1/2 mutation, while the tumor was HRD-positive, PD-L1-positive, and folate receptor alpha-positive.

After an 8-month disease-free interval, the cancer recurred widely in the abdomen, chest, and cervical lymph nodes. About 24 months after the original diagnosis, while receiving fourth-line weekly paclitaxel, she developed a painful 5.5 cm right breast mass with axillary lymph-node enlargement. Biopsies of the breast and axillary nodes confirmed that these were metastases from the ovarian cancer, not a new breast primary.

She received palliative radiation to the breast, followed by pembrolizumab and olaparib, with an initially strong clinical and imaging response. Eight months later, disease returned in the previously treated breast area. She subsequently moved through additional therapy and was receiving seventh-line mirvetuximab-soravtansine at the latest follow-up. About 2 years after the breast metastasis was first diagnosed, she remained alive with stable disease.