Merkel cell carcinoma. Prognosis and management

Seventy patients with Merkel cell carcinoma were treated at Memorial Sloan-kettering Cancer Center between 1969 and 1989. The overall estimated 5-year survival rate was 64%. Factors predictive of improved survival included head and neck site and negative lymph nodes at presentation. Local recurrence was seen in 18 patients (26%) and did not correlate with patient-, tumor-, or treatment-related variables. Nine patients with local recurrence (50%) were free of disease following aggressive reoperation. Regional nodes were involved at some point during the course of the disease in forty-six patients (66%). Regional lymph node involvement was apparent within 2 years of diagnosis in 40 (87%) of 46 patients in whom it occurred. Systemic disease was nearly uniformly preceded by the appearance of nodal metastases and was uniformly fatal regardless of subsequent therapy. This suggests an orderly "cascade" pattern of spread for this tumor, in which elective regional lymph node dissection may be justified. Our recommendations for treatment include a wide excision of the primary tumor and either elective or early therapeutic regional node dissection. The role of adjuvant radiotherapy or chemotherapy remains unproven.