The role of radiotherapy in the management of primary cutaneous neuroendocrine tumors (merkel cell or trabecular carcinoma): Experience at the peter maccallum cancer institute (Melbourne, Australia)

Abstract

Clinical presentation, treatment, and radiation response data are presented for 20 patients with primary cutaneous neuroendocrine tumors (Merkel cell or trabecular carcinoma). Thirty-six sites were irradiated, 26 sites were local recurrences after surgery or metastases, only 3 primary tumors were irradiated de novo. In 22 out of 23 sites (96%) a complete response of measurable tumor was observed and 1 partial response (4%), an overall response rate of 100%. Thirteen sites were irradiated prophylactically with no measurable disease present and no recurrences have been seen in these areas. There was only 1 recurrence in an irradiated site (after a low radiation dose). Forty percent (8/20) either had distant metastases at presentation (5 patients) or developed them after radiotherapy (3 patients) and five of these patients have died of metastatic disease. Follow-up time ranged from 1-77 months, and actuarial 5-year survival was 63%. In view of these findings we would advocate the wider study of primary radiotherapy after biopsy or excision biopsy for the primary lesion, and prophylactic nodal irradiation with the object of avoiding extensive surgery in these often elderly patients.