Analysis of cutaneous Merkel Cell Carcinoma outcomes after different surgical interventions

Background Current guidelines recommend local excision margin (EM) with 1 to 2cm on primary merkel cell carcinoma (MCC) site. Objective We compared survival outcomes of MCC patients treated with different surgical interventions. Methods A retrospective analysis of MCC cases in the SEER database was performed by Kaplan-Meier, competing risk and Cox proportional hazards regression model analyses. Influence of age, T stage, AJCC stage, adjuvant radiotherapy and other subgroups were also analyzed by pair-wise log-rank test. Results Our results indicated significant association between local destruction method and inferior survival, while EM>2cm showed significantly higher overall survival (OS). In addition, competing risk analysis depicted similar trend as Kaplan-Meier analysis, and considerably reduced estimated cumulative incidence. Further subgroup pair-wise analysis demonstrated that EM>2cm method had better survival in patients younger than 60 years, having smaller tumor diameters (T1 and T2) or undergone adjuvant radiotherapy (p Limitations This study was not prospectively randomized without relapse data. Conclusions It is challenging to make optimal EM recommendations, as surgical options may depend on individual case situations. Further prospective randomized studies are warranted.