Importance: Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous malignancy. Lesions often present in the head and neck region and represent a unique cohort of patients with likely region-specific prognosis and outcomes. Large-sample studies are needed to assess the epidemiology and outcomes of this disease.
Objective: To describe the incidence and determinants of survival in patients with cutaneous MCC of the head and neck between the years of 1973 to 2012 using the Surveillance, Epidemiology, and End Result (SEER) database.
Study Design: Retrospective cohort study of patients in the SEER tumor registry who were diagnosed with MCC of the head and neck from 1973 to 2012
Results: A total of 3395 cases of MCC of the head & neck were identified. The cohort was composed of 62.8% males. The mean age at diagnosis was 76.7 years. The face and scalp/neck were the most common sites at 60.5% and 21.9%, respectively. The majority of patients (66.4%) presented with stage I and II disease. Most lesions were confined to the dermis (71.3%) or extended into subcutaneous tissue (19.4%). Nodal disease was present in 22.0% of cases. The median overall survival (OS) was 35.3 months. 88.0% of cases underwent surgical management and 39.7% underwent surgery and radiation therapy. OS at 2, 5, and 10 years were 49%, 33%, and 19%, respectively. On multivariate analysis, male sex, scalp and lip involvement, stage, nodal disease, and tumor extension were all associated with worse OS (p<.001) and disease specific survival (DSS) (p<.001). Surgical therapy improved OS (p<.001) and DSS (p<.001).
Conclusion: Merkel cell carcinoma of the head and neck is associated with a generally poor prognosis. Stage, nodal disease, primary scalp and lip, and tumor extension are independent predictors of OS and DSS. Surgical therapy is an independent predictor of OS and DSS and should be considered as part of the treatment algorithm to maximize survival.