Durable response to eribulin in metastatic primary ovarian leiomyosarcoma: A case report

Primary ovarian leiomyosarcoma is an exceptionally rare malignancy that accounts for <0.1% of ovarian cancers; however, evidence regarding effective systemic therapy for advanced disease remains limited.Treatment strategies are generally extrapolated from uterine leiomyosarcoma or soft tissue sarcoma regimens; however, therapeutic outcomes are inconsistent.The current report describes the case of a 77-year-old female patient with International Federation of Gynecology and Obstetrics stage IVB primary ovarian leiomyosarcoma who presented with liver and humeral metastases.Following surgery, the patient underwent three cycles of combination therapy with docetaxel and gemcitabine, but the disease progressed.The patient discontinued treatment with pazopanib due to grade 3 dermatologic toxicity.Eribulin treatment was initiated because anthracyclines were contraindicated due to cardiac dysfunction.After seven cycles, the humeral metastases completely resolved, and the liver metastases remained stable, thereby achieving a partial response.Disease control was maintained for ~10 months without significant adverse events, with preservation of quality of life.After the 13th cycle, new hepatic and pulmonary metastases developed and comprehensive genomic profiling revealed no actionable alterations.To the best of our knowledge, the present report is the first to demonstrate clinically meaningful and durable disease control using eribulin in advanced primary ovarian leiomyosarcoma.