Clinical and Epidemiological Characteristics of Merkel Cell Carcinoma in a Series of 38 Patients

Merkel cell carcinoma is a rare yet aggressive cutaneous tumor with a poor prognosis. Few studies have analyzed series of patients from the same hospital.

We performed a retrospective, descriptive, observational study of all patients diagnosed with Merkel cell carcinoma at a tertiary care hospital between 2002 and 2017. We recorded epidemiological, clinical, and histologic data and information on treatments and survival. For analysis, the sample was divided into 2 groups from different periods: 2002-2009 and 2010-2017. We performed survival analysis using Kaplan-Meier curves and multivariate analysis using a Cox proportional hazards model.

Thirty-eight patients (24 men and 14 women) with a mean age of 77.76 years were included. Mean follow-up time was 30.11 months. On comparing 2010-2017 with 2002-2009, we observed a 116% increase in the number of Merkel cell carcinoma cases (26 vs. 12), an older mean age at diagnosis (80.92 vs. 70.92 years, P<.05), and an increase in lesions located on the trunk and lower limbs (0% vs. 34.62%). Eleven patients died of Merkel cell carcinoma. Overall survival was 78.2% at 12 months and 69.3% at 24 months. In the univariate analysis, age over 70 years and lymph node involvement were associated with mortality, while tumor location on the upper extremities and wide surgical excision were associated with improved survival. Only lymph node involvement retained its prognostic significance in the multivariate analysis.

In this series, we observed that Merkel cell carcinoma has become more common in recent years and is now diagnosed at an older age and found in new anatomic locations.