Response to chemotherapy and predictors of survival in adult rhabdomyosarcoma.

Abstract

To assess outcome and identify predictors of survival of adults with rhabdomyosarcoma. The literature on adult rhabdomyosarcoma is limited. Few studies have identified predictors of long-term survival in this patient population. Thirty-nine adults with rhabdomyosarcoma were treated between 1973 and 1996 and prospectively followed. Outcomes were assessed with respect to patient and tumor characteristics, local treatment, and response to chemotherapy. Twenty-six patients had localized/locoregional disease and 13 patients had metastatic disease at presentation. Twenty-one patients underwent attempted curative resection, 27 received radiotherapy, and 37 received chemotherapy. Median follow-up for surviving patients was 152 months. The overall 5- and 10-year survival rates were 31% and 27%, respectively. Five-year survival rates for patients with tumors less than 5 cm, 5 to 10 cm, and more than 10 cm were 60%, 14%, and 0%, respectively. Patients with localized/locoregional disease at presentation had a 44% 5-year survival rate; there were no 5-year survivors among patients with metastatic disease. Patients who had a complete response to chemotherapy had a 5-year survival rate of 57%, compared with a rate of only 7% for poor responders. Metastatic disease at presentation and poor response to chemotherapy were independent predictors of death on multivariate analysis. Age, location, nodal status, and histologic subtype do not appear be associated with survival in adults with rhabdomyosarcoma treated with multimodal therapy. Metastatic disease at presentation and poor response to chemotherapy are strongly associated with poor prognosis. Future systemic therapies should be targeted to patients with localized/locoregional disease and partial responders to conventional chemotherapy.