Prognostic significance of regional lymph node involvement in childhood extremity rhabdomyosarcoma.

Thirty-four patients with extremity rhabdomyosarcoma were treated at Memorial Sloan-Kettering Cancer Center during the years 1970 to 1987. The regional lymph node status at diagnosis was histologically confirmed in 27 patients. Of these 27 patients, there were 20 males and 7 females, ranging in age from 6 months to 22 years (median 10 years). The primary tumor was located in the upper and lower extremity in 11 and 16 patients, respectively. The histologic subtypes included embryonal in 13 patients and alveolar in 14 patients. Fourteen patients had no evidence of regional lymph node involvement (N0) and 13 patients had lymphatic metastases (N1). All patients were further staged according to the extent of surgical resection, the local invasiveness and size of the primary tumor, and the presence (M1) or absence (M0) of distant metastases. With a median follow-up time from diagnosis of 9.2 years (minimum 5.3 years), the overall survival was 48% (13/27): N0, 12/14 and N1, 1/13 (P = .0002). Excluding those patients with M1 disease, the survival rate was: N0, 11/12; N1, 1/10 (P = .0001). The first site of relapse in the M0 patients was distant metastases in 8/10 cases. Our results suggest that regional lymph node involvement at diagnosis is an important prognostic factor in extremity RMS. Its presence appears to be associated with a high incidence of relapse in metastatic sites and poor survival outcome.