What comprises appropriate therapy for children/adolescents with rhabdomyosarcoma arising in the abdominal wall? A report from the Intergroup Rhabdomyosarcoma Study Group.

PURPOSE

The aim of this study was to define clinical features and determine the best therapy for patients with rhabdomyosarcoma (RMS) of the abdominal wall.

METHODS

We examined the demographic, clinical features, therapy (especially surgical), and outcome of 34 patients. Patients received combination chemotherapy after complete surgical resection (group I, n = 14; 41%); resection with microscopic residual followed by local irradiation (RT; group II, n = 8; 24%); partial resection or biopsy only plus RT with gross locoregional residual tumor (group III, n = 4; 12%); or biopsy only plus RT with metastatic disease (group IV, n = 8; 24%). Patients with group I or group II tumors had undergone partial abdominal wall resection (ie, involved muscle only with preservation of peritoneum, n = 11) or complete abdominal wall resection (n = 7). Four additional patients had groin lesions.

RESULTS

Thirty-four children or adolescents with abdominal wall RMS (about 1% of all patients) were treated on Intergroup Rhabdomyosarcoma Study I (IRS-I) through IRS-IV. Overall, adolescents comprised 14 of 34 eligible patients (41%), and 10 of 14 (71%) adolescents had alveolar or undifferentiated tumors versus 8 of 20 (40%) younger children (P= .07). Failure-free survival (FFS) rate and survival rate at 5 years was 65%. Treatment outcome was poorer for patients with group III-IV tumors (P = .01), adolescents (P = .09) and patients with alveolar or undifferentiated sarcomas (P = .12).

CONCLUSION

Patients with localized tumors appear to fare better if they undergo complete abdominal wall resection (long-term survival rate, 100%) versus partial resection (long-term survival rate, 62% [P = .12]).