Effects of surgery on survival of patients aged 75 years or older with Merkel cell carcinoma

Objective To investigate whether surgery improves prognosis in elderly patients with Merkel cell carcinoma (MCC). Materials/Methods Data of all patients with MCC diagnosed between 2004 and 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Differences in baseline characteristics were analyzed among the age groups (75-80, 80-85, and >= 85 years). Multivariate Cox proportional hazards analysis was used to assess the effects of each variable on patient outcomes. The Kaplan-Meier curves were employed to evaluate MCC overall survival (OS) and MCC-specific survival (MSS). Results A total of 1156 of patients with MCC met the inclusion and exclusion criteria. The surgery rate decreased with age (75-80, 80-85, and >= 85 years were 93.3%, 91.1%, and 88.7%, respectively; p = 0.082). Multivariate Cox proportional hazards analysis showed that the OS of patients in the 80-85 years group (hazard ratio [HR] = 1.39; 95% confidence interval [CI] = 1.14-1.70; p = 0.001) and the >= 85 years group (HR = 2.18; 95% CI = 1.80-2.63; p < 0.0001) was worse than that in the 75-80 years group. Compared with the non-surgery groups, the HR for the surgery group was 0.75 for OS (95% CI = 0.56-1.00; p = 0.048) and 0.73 for MSS (95% CI = 0.48-1.10; p = 0.130). Subgroup analyses showed that patients aged >= 85 years undergoing surgery had better OS (HR = 0.65; 95% CI = 0.45-0.95; p = 0.024). Conclusions MCC patients aged 75 years and older would benefit from surgical resection. However, surgical resection should be performed cautiously, and larger prospective clinical trials are needed to further verify these findings.