Triple-negative breast cancer and ovarian cancer treated with chemotherapy and PARP inhibitor

What happened, in summary

A 45-year-old woman had originally been treated in 2019 for multifocal, clinical T2N0M0 triple-negative invasive ductal carcinoma of the left breast. That first treatment included neoadjuvant chemotherapy, bilateral total mastectomy with immediate implant reconstruction, and left sentinel lymph node biopsy, with a pathologic complete response and no adjuvant radiation. In January 2022, she developed a biopsy-proven locoregional recurrence after noticing a palpable nodularity in the left tail of Spence. PET imaging showed a 2-cm lesion near the left breast implant and a 1-cm left axillary lymph node. The same scan also revealed bilateral ovarian lesions and peritoneal carcinomatosis, and diagnostic laparoscopy confirmed synchronous FIGO Stage IIIC high-grade serous ovarian cancer. No distant visceral or bone metastases were reported. Genetic testing found a germline pathogenic BRCA2 mutation. She underwent complete surgical cytoreduction for ovarian cancer, followed by 6 cycles of carboplatin and paclitaxel from May to August 2022, which also served as neoadjuvant chemotherapy for the recurrent breast cancer. In September 2022, left lumpectomy with sentinel lymph node biopsy and targeted axillary dissection found a 2.5-mm residual grade 2 triple-negative carcinoma, clear margins, and 1 of 10 nodes with a 3-mm metastasis. She started oral olaparib 300 mg twice daily in October 2022. From 13 December 2022 to 18 January 2023, she received 50 Gy in 25 fractions to the left reconstructed breast and regional nodes, with olaparib reduced during radiation. At 6-week follow-up, the exam was unremarkable. During radiation, she developed faint erythema, mild swallowing discomfort, and temporary lymphopenia; by follow-up, the skin reaction and symptoms had resolved.