What constitutes optimal therapy for patients with rhabdomyosarcoma of the female genital tract?

BACKGROUND. Factors affecting outcome for rhabdomyosarcoma (RMS) of the female genital tract in patients treated on Intergroup Rhabdomyosarcoma Study Group (IRSG) protocols I-IV were evaluated to define optimal therapy. METHODS. Records of 151 patients with tumors of the female genital tract who were treated on IRSG protocols I-IV were reviewed for details regarding chemotherapy, surgery, radiotherapy (RT), and outcome. RESULTS. The overall 5-year survival was 82%, (87% for patients with locoregional tumors). Chemotherapy was primarily vincristine, actinomycin-D, and cyclophosphamide (VAC) based. Local therapy was surgery alone in 42% of patients, surgery plus RT in 19% of patients, biopsy plus RT in 12% of patients, and biopsy without RT in 21% of patients. The rate of hysterectomy decreased from 48% in IRS-I/II to 22% in IRS-III/IV with an increase in the use of RT from 23% in IRS-II to 45% in IRS-IV and continued excellent survival. Many patients with vaginal primary tumors received delayed RT or had it omitted on later studies with excellent outcome. For patients with localized embryonal/botryoid tumors, there were no significant differences in 5-year survival among patients with tumors at different sites or among patients treated on IRS-I-IV. In patients with Group I-III tumors, 43% of deaths were from toxicity. Analysis of prognostic factors, with toxic deaths censored, revealed that an age of 1-9 years at the time of diagnosis, noninvasive tumors, and the use of IRS-II or IRS-IV treatments were associated significantly with better outcome. Patients ages 1-9 years fared best (5-year survival of 98%) and patients outside of this age range especially benefited from the intensified therapy used in IRS-III or IRS-IV (5-year survival of 67% on the IRS-I/II vs. 90% in IRS-III/IV). CONCLUSIONS. Localized female genital RMS usually is curable with combination chemotherapy, a conservative surgical approach, and the use of RT for selected patients.