Fellow Providence Saint John’s Cancer Institute Santa Monica, California, United States
Disclosure: Disclosure information not submitted.
Participants should be aware of the following financial/non-financial relationships:
Sean Nassoiy, DO: Disclosure information not submitted.
Introduction: Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor.Current NCCN guidelines recommend 1-2cm margins around the primary tumor, and sentinel lymph node biopsy (SLNB) for staging. However, there is no clear consensus on the appropriate surgical margins, and recent data demonstrates conflicting results. The objective of this study was to determine if a wider surgical excision was associated with improved overall survival.
Methods: Utilizing the National Cancer Database from 2004 – 2017, patients with early stage (T1/2), clinically node negative (N0) MCC who were >18 years old and underwent wide excision (WE) were identified.Patients were then stratified into 3 groups based on their surgical management; < 1cm WE margin, >1cm WE margin and Mohs micrographic surgery (MMS).Multivariate logistic regression was used to determine independent factors for R0 resection and receipt of radiation.Overall survival (OS) with Kaplan-Meier and log-rank tests, followed by Cox proportional-hazards regression with inverse probability weighting using propensity score method was performed to examine the risk of death.
Results: In total, 7257 patients were included in the final study cohort.More than 53% received >1cm WE (n=3850), followed by 41% < 1cm WE (n=2956), and the remainder MMS (n=451). Of the entire cohort, 59% underwent a SLNB, and 51% received adjuvant radiation.After adjusting for confounders, patients were more likely to undergo a R0 resection with >1cm WE (OR 3.2; 95%CI 2.6-3.9) and MMS (OR 3,5; 95%CI 2.3-5.3).R0 resection (HR 0.69; 95%CI 0.61-0.77), and receipt of radiation were both independently associated with improved OS (HR 0.80; 95%CI 0.74-0.86).Other factors associated with improved OS included younger age (18-69), lower co-morbidity score, T1 tumors, SLNB performed, and female sex (all p< 0.05).
Conclusions: For early stage MCC, R0 resection as opposed to a wider surgical excision was associated with improved OS.This remained true even after controlling for the receipt of radiation. Future studies should investigate the role of intraoperative margin evaluation.
Learning Objectives:
Upon completion, participant will be able to explain what qualifies a T1/2 merkel cell carcinoma.
Upon completion, participant will be able to explain what the appropriate surgical management if for T1/2 merkel cell carcinoma.
Upon completion, participant will be able to explain the effect that radiation has on overall survival for T1/2 merkel cell carcinoma.
