Improved prognosis with intensive treatment of children with cranial soft tissue sarcomas arising in nonorbital parameningeal sites. A report from the Intergroup Rhabdomyosarcoma Study.

In the first Intergroup Rhabdomyosarcoma Study (IRS-I), it was found that, of 57 patients with nonorbital cranial parameningeal sarcoma treated from 1972 to 1976, 20 patients (35%) developed meningeal sarcoma and 90% (18/20) died of this complication. Since about half of these 20 patients had received inadequate radiation therapy and all had radiation therapy delayed until week 6, the treatment program was modified in December 1977 to begin radiation therapy on day 0 to the entire neuraxis and the primary tumor for all patients presenting with one or more risk factors indicating a high risk of meningeal involvement, and to administer periodic intrathecal medications to the same patients. The risk factors were intracranial extension of tumor, bony erosion at the cranial base, and cranial nerve palsy. In this report, the prognoses of two groups of patients with nonorbital cranial parameningeal sarcoma are compared: 95 patients treated before modification of the protocol in December 1977 with chemotherapy and nonintensive meningeal radiotherapy (preintensive group) and 68 patients treated subsequently with intensive meningeal radiotherapy and chemotherapy (intensive group). All patients received vincristine and actinomycin D (dactinomycin) with or without cyclophosphamide and Adriamycin (doxorubicin), according to the protocol. Radiation therapy consisted of 4000 to 5500 rad to the primary tumor in 5 to 6 weeks for most patients. The intensively treated patients also received intrathecal drugs via lumbar puncture and whole cranial or craniospinal radiation when one or more meningeal risk factors were present. In the preintensive group, the complete remission rate was 68% (65/95); the percentages of patients tumor free or alive at 3 years were 33% and 41%, respectively. In intensively treated patients, the complete remission rate was 76% (52/68); the percentages of patients tumor free or alive at 3 years were 57% and 68%, respectively. The improvements in the percentages of intensively treated patients tumor free or surviving were highly statistically significant (P less than 0.01 for both comparisons). Within the intensive treatment group, meningeal involvement at diagnosis was an unfavorable prognostic sign, since patients with no meningeal involvement had much better tumor-free survival at 3 years (81% vs. 51%) and survival (90% vs. 57%) than patients with evidence of meningeal involvement; the differences were highly statistically significant (P = 0.01).