PRESERVATION OF THE BLADDER IN PATIENTS WITH RHABDOMYOSARCOMA

Purpose: To review the pathologic findings from children with gross re sidual rhabdomyosarcoma (RMS) of the bladder and compare the treatment outcome of those who underwent cystectomy with those who did not. Pat ients and Methods: Primary and follow-up records and pathology specime ns for 28 patients with gross residual disease entered onto the Interg roup Rhabdomyosarcoma Study (IRS) III were reviewed. These patients we re assigned to receive 20 weeks of multiagent induction chemotherapy a nd 4 weeks of radiotherapy. Future therapy decisions were based on cli nical and histologic evaluation at 20 weeks. Results: All patients had a clinical and histologic response, Thirteen patients underwent cyste ctomy at intervals that ranged from 1.5 to 38 months after the start o f therapy. All hut one patient ore alive and well without recurrence, Reasons for cystectomy included presumed evidence of tumor growth from imaging studies, findings at cystoscopy, or histologic interpretation of biopsies. In 12 of 14 specimens from 15 patients who retained thei r bladder, no tumor cells were seen at first or second evaluation. In cystectomy specimens, tumor cellularity was markedly reduced and all t umor cells were in varying degrees of cellular maturation, Review of p rimary tumor specimens showed a greater degree of cellular maturation in patients with retained bladders than in those who underwent cystect omy. Conclusion: Bladder RMS is responsive to chemotherapy and radioth erapy. Twelve of 26 patients showed complete loss of tumor cells after induction therapy. Cystectomy specimens showed diminished tumor cells with varying degrees of cellular maturation. It is hypothesized that these tumors may have shown further maturation and ultimate loss of ma tured cells with continuing therapy. (C) 1997 by American Society of C linical Oncology.