Multimodality management of Merkel cell carcinoma

Hypothesis: Merkel cell carcinoma is a rare dermal neuroendocrine carcinoma whose optimal treatment and prognostic factors are poorly defined. We hypo thesize that high-risk patients with Merkel cell carcinoma are best treated with multimodality therapy. Design: A retrospective review of all patients (N = 33) with Merkel cell ca rcinoma treated at the Massachusetts General Hospital from January 1, 1980, to August 24, 1997. Median follow-up time was 37 months (range, 6-157 mont hs). Patients: Adequate data for evaluation were available for 31 patients. Male to female distribution was 14 men and 17 women, with a median patient age of 68 years. Main Outcome Measure: Stage at presentation; factors associated with recurr ence; and the effects of surgery, radiation therapy (XRT), and chemotherapy on recurrence, salvage, and survival rates. Results: There were 12 extremity, 11 head and neck, and 8 truncal tumors. T here were 22 isolated primary tumors, 8 with additional clinically positive lymph nodes, and 1 with distant disease. Therapy was local excision with o r without XRT in 19 patients, local resection and lymphadenectomy with or w ithout XRT in 8 patients, and XRT alone in 4 patients with head and neck tu mors. Fifteen patients developed recurrences (7 local, 8 nodal, and 10 dist ant). Median time to recurrence was 8 months (range, 3-48 months). There we re 7 tumor-related deaths, 6 of which were associated with truncal lesions (P<.001). No locoregional recurrences occurred inpatients with margins of r esection of 2 cm or greater or adequate XRT, A multivariate analysis select ed truncal location (P = .005) and nodal disease (P = .05) as predictors of mortality. Remission was possible in 5 patients with locoregional and 2 pa tients with distant recurrences. Conclusions: Merkel cell carcinoma is an aggressive dermal cancer with freq uent nodal metastases; truncal tumors have the worst prognosis. Locoregiona l recurrence correlates with inadequate margins and lack of XRT, but remiss ion is possible with multimodality therapy.