Rhabdomyosarcoma: the Stanford experience using a TNM staging system.

Abstract

Seventy-four patients with rhabdomyosarcoma were initially staged according to the Intergroup Rhabdomyosarcoma Study (IRS) grouping classification and then retrospectively using a TNM staging system based on the initial clinical extent of disease. The TNM system includes T1, tumor confined to site or organ of origin; T2, regional extension beyond the site of origin; N0, normal lymph nodes; N1, lymph nodes containing tumor; M0, no evidence of metastases; and M1, distant metastases. All patients received combination chemotherapy, and more than 90% received radiation therapy as part of their initial treatment program with curative intent. Fifty-three of 74 patients (72%) were group III according to the IRS system, indicating unresectable or gross residual tumor. A more uniform distribution was achieved using the TNM system. Freedom from relapse (FFR) was 43% and the actuarial survival rate was 47% for the entire study group at 10 years. All but one relapse occurred within 3 years of initial diagnosis, and only three of 38 relapsed patients were salvaged. All TNM stage I patients are surviving disease free. Among patients having stages II, III, and IV disease by the TNM system, FFR was 53%, 26%, and 11%, and the survival rates were 47%, 36%, and 33%, respectively. Thirty-two of 74 patients (43%) had evidence of lymph node involvement at presentation, and 28 (88%) of these had primary lesions that extended beyond the site of origin (T2 primary). Histologic subtype and primary site had little impact on outcome in a multivariate analysis, and T stage was identified as the single most significant covariate correlated with survival; a model composed of both T stage and M stage was the best one for predicting relapse. The presented data support a study using a prospectively assigned TNM staging system based on the initial clinical extent of disease for use in future therapeutic trials.