Prognostic factors and surgical treatment guidelines for children with rhabdomyosarcoma of the perineum or anus: A report of intergroup rhabdomyosarcoma studies I through IV, 1972 through 1997

Background/Purpose: Rhabdomyosarcoma (RMS) of the perineum or anus is a rare sarcoma of childhood with a poor prognosis. This study reviews the Intergroup Rhabdomyosarcoma Study Group (IRSG) studies I through IV to identify determinants of patient outcome and to refine surgical treatment guidelines. Methods: From 1972 through 1997, 71 eligible patients were treated and studied. The median patient age was 6 years. The majority (64%) were at an advanced stage (clinical group III and IV) at initial presentation and 50% had positive regional lymph node (LN) involvement. Results: The 5-year failure-free survival rate (FFS) for all patients was 45% and the overall survival rate (OS) was 49%. Characteristics that were associated with significantly improved survival rate were primary tumor size less than 5 cm, lower (less advanced) clinical group and stage, negative regional lymph node status, and age less than 10 years. When the extent of disease was controlled for in multivariate analysis, only age less than 10 predicted an improved outcome. The 5-year overall survival rate for patients less than 10 years of age was 71% versus 20% in older patients (P < .001). Histology (alveolar versus embryonal) and primary site (perineal versus anal) did not significantly affect outcome. Conclusions: Because of the high incidence of regional LN involvement in these patients, a strategy of routine surgical evaluation of ilioinguinal lymph nodes in all patients with perineal or anal RMS is recommended.