A MULTIDISCIPLINARY APPROACH TO THERAPY FOR UNRESECTABLE MALIGNANT THYMOMA

Background: The therapeutic outcome for unresectable, locally advanced , malignant thymoma has been poor. Objective: To improve tumor resecta bility and patient survival rates by studying a multimodal approach to therapy for unresectable malignant thymoma. Design: Prospective cohor t study. Setting: Tertiary care cancer center. Participants: All eligi ble patients had newly diagnosed, histologically proven, unresectable malignant thymoma. Intervention: The treatment regimen consisted of in duction chemotherapy (three courses of cyclophosphamide, doxorubicin, cisplatin, and prednisone), surgical resection, postoperative radiatio n therapy, and consolidation chemotherapy (three courses of cyclophosp hamide, doxorubicin, cisplatin, and prednisone). Tissue samples were t aken at the time of surgical resection for assessment of tumor necrosi s and Ki-67 expression. Measurements: Tumor response and resectability (both overall and after induction chemotherapy) and disease-free surv ival rate in patients who received multimodal therapy. Results: 13 pat ients were consecutively enrolled from February 1990 to December 1996, and 12 evaluable patients were assessed for response. Disease respond ed to induction chemotherapy completely in 3 patients (25%) and partia lly in 8 patients (67%); 1 patient had a minor response (8%). Eleven p atients had surgical resection; 1 refused surgery. Tumors were removed completely in 9 (82%) and incompletely in 2 (18%) of 11 patients who had been receiving radiation therapy and consolidation chemotherapy. A ll 12 patients are alive (100% at 7 years), with a median follow-up of 43 months, and 10 patients are disease free (73 % disease-free surviv al at 7 years). A high correlation was seen between tumor necrosis aft er induction chemotherapy and Ki-67 expression (r = -0.88). Conclusion s: Aggressive multimodal treatment is highly effective and may cure lo cally advanced, unresectable malignant thymoma.