Clinicopathologic analysis of patients with adult rhabdomyosarcoma

BACKGROUND. Rhabdomyosarcoma (RMS) in adults (age greater than or equal to 16 years) is rare, accounting for less than 3% of adult soft tissue sarcoma s. There is little information describing the disease biology or clinicopat hologic factors that influence survival in adults with RMS. The objective o f this study was to define the factors in patients with adult RMS that pred ict outcome, disease progression, and survival. METHODS. Eighty-four adult patients with a pathologic diagnosis of RMS that was confirmed by immunohistochemistry were identified by a prospective inp atient data base during the period 1982-1999 and were analyzed for disease specific survival and metastasis free survival using the Kaplan-Meier actua rial method. Statistical significance was evaluated using the log-rank test for univariate influence and a Cox regression model for multivariate influ ence. RESULTS. The median disease specific survival was 22 months. Patient age, e xtent of disease, tumor size at the time of diagnosis, and margin status af ter resection were significant predictors of disease specific survival. Pat ients who underwent a complete resection had a significantly longer median survival (105 months) compared with any other subgroup of patients. The his tologic subtype did not predict patient survival but did vary with patient age. Most notably, the proportion of the pleomorphic subtype increased with advancing age, accounting for 42% of RMS in patients over the age of 40 pa rs. CONCLUSIONS. The most important predictors of outcome in patients with adul t RMS are patient age, tumor size, extent of disease, and margin status aft er resection. In contrast to patients with pediatric RMS, no association wa s noted between survival and histologic subtype in this group of patients w ith adult RMS. All histologic subtypes of RMS are aggressive malignancies w ith poor disease specific survival despite aggressive multimodality managem ent. (C) 2001 American Cancer Society.