Cutaneous Merkel cell carcinoma

The aim of this study was to describe the treatment outcomes of patients with cutaneous Merkel cell carcinoma managed with curative intent.

Between December 1984 and November 2009, 40 patients with previously untreated Merkel cell carcinoma were managed with curative intent with radiotherapy alone (3 patients) or combined with surgery (37 patients). Adjuvant chemotherapy was administered to 11 patients. Primary sites were the following: head and neck, 32 patients; extremities, 6 patients; and trunk, 2 patients. Patients were staged according to the Yiengpruksawan staging system: stage I, local disease; stage II, regional disease; and stage III, distant metastases. Twenty-four patients had stage I disease, and 16 patients had stage II disease. Median follow-up on all patients was 3.0 years (range, 0.6-15.6 years). Median follow-up on survivors was 4.2 years (range, 2.2-14.2 years).

The 5-year outcomes were local control, 92%; regional control, 78%; local-regional control, 79%; distant metastasis-free survival, 57%; cause-specific survival, 45%; and overall survival, 36%. The 5-year outcomes for those with stage I vs stage II disease were the following: local-regional control, 87% and 67% (P = .1607); distant metastasis-free survival, 71% and 37% (P = .0073); cause-specific survival, 58% and 27% (P = .0090); and overall survival, 48% and 18% (P = .0037). Local-regional recurrences were observed in 6 patients; one patient was successfully salvaged. Severe complications were observed in 3 patients.

Radiotherapy alone or combined with surgery results in a high local-regional control rate. The main mode of recurrence is distant. Approximately one half of patients are cured.