[A Case of Hormone Receptor-Positive, HER2-Negative Metastatic Recurrent Breast Cancer Successfully Treated with Capivasertib and Fulvestrant in Late-Line Therapy].

A 60-year-old woman who underwent mastectomy for right breast cancer 21 years ago was treated with endocrine therapy, chemotherapy and radiation therapy over a 13-year period following recurrence involving distant lymph nodes, bone, and lung metastases. She also underwent Lt. burr hole opening biopsy and Ommaya reservoir placement and gamma knife therapy for brain metastases at another hospital. She was referred to the university hospital for comprehensive genomic profiling test of the brain metastases specimen, which revealed PIK3CA and PTEN mutation. However, no targeted drugs were available through public health insurance at the time, and she continued treatment with other therapies. With progressive bilateral lung metastases, and following the insurance approval of capivasertib in Japan, she was started on combination therapy with capivasertib and fulvestrant. The treatment resulted in a partial response, with a progression-free survival of 8 months. In the CAPItello-291 trial, capivasertib and fulvestrant demonstrated efficacy in patients with up to two prior lines endocrine therapy, but its use in late-line settings has not yet been reported. In this article, we report a case of a woman with metastatic recurrent breast cancer who was treated with capivasertib and fulvestrant was used as the late-line treatment, resulting in a progression-free survival of 8 months.