Embryonal rhabdomyosarcoma: adjuvant and ex vivo assay-directed chemotherapy.

The aim of this retrospective study was to evaluate differences in treatment of embryonal rhabdomyosarcoma (RMS) of the uterus in 2 premenopausal women. We discuss adjuvant chemotherapy and use of ChemoFx Assay (Precision Therapeutics, Pittsburgh, PA) to guide choice of active chemotherapeutic agents. Two premenopausal patients were identified with a pathologic diagnosis of embryonal RMS of the uterus. Both met inclusion criteria for the study. A 21-year-old woman underwent a staging abdominal hysterectomy for a variant of embryonal RMS. Vincristine, actinomycin D, and cyclophosphamide were given adjunctively for a complete response. A 20-year-old woman underwent a diagnostic dilation and curettage revealing embryonal RMS. Initial treatment included an abdominal hysterectomy and nodal sampling. Presentation to a subsequent gynecologic oncologist 7 months later revealed recurrence. Carboplatin, doxorubicin, and paclitaxel provided a partial response. After a second surgical resection, ChemoFx Assay identified ifosfamide and mitomycin C as active agents and resulted in a complete response. Recommended treatment includes surgery and chemotherapy with possible radiation therapy if deemed necessary. The benefit of adding neoadjuvant or adjuvant chemotherapy and radiation therapy allows for a conservative surgical approach and improved survival. Choosing active chemotherapy agents can be aided by ChemoFx Assay. The chemotherapy most commonly used for treatment of embryonal RMS is a combination of vincristine, actinomycin D, and cyclophosphamide.