THE IMPORTANCE OF POSTOPERATIVE RADIATION-THERAPY IN THE TREATMENT OFMERKEL CELL-CARCINOMA

Purpose: To determine the role of postoperative radiation therapy in t he treatment of Merkel cell carcinoma (MCC). Methods and Materials: Ei ghty patients with MCC of the skin were treated with curative intent a t the Queensland Radium Institute between 1981 and 1991. Fifty-one pat ients (63.7%) were referred after initial biopsy for further treatment and 29 patients (36.3%) were referred with locally recurrent disease following primary surgery elsewhere. Thirteen patients (16.3%) present ed with nodal disease without a clinically definable primary skin lesi on. Results: Of the 80 patients, 38 had undergone surgery (S) alone, 3 4 surgery plus radiotherapy (S + RT), 7 RT after incomplete S, and 1 p atient had chemotherapy (CT) plus RT, Overall survival at 36 months fo r all patients was 68%, All of the 38 patients treated with S alone re lapsed, The median time to recurrence was 5.5 months, Ten of the 34 pa tients treated with S + RT relapsed. The median time to recurrence was 16.5 months. Of the 80 patients, 55 have relapsed after primary treat ment, 25 have developed systemic metastases, and 26 patients have died as a direct result of MCC. Conclusion: Our large series confirms earl ier reports from this Institute and highlights the importance of S + R T over S alone in preventing local recurrence of this highly malignant skin cancer.