No difference in overall survival for primary cutaneous Merkel cell carcinoma after Mohs micrographic surgery and wide local excision: A multicenter cohort analysis

June 6, 2024


Journal of American Academy of Dermatology

Publication Date

June 6, 2024


Sharma A, Demer A Summary

When treating Merkel cell carcinoma (MCC) that hasn’t spread yet, doctors often use surgery, but the best surgical approach is unclear. This study looked at two types of surgery: one where they remove thin layers of skin and check them under a microscope during the surgery to ensure no cancer cells remain (Mohs surgery; What is Mohs surgery? ( and another where they remove the visible tumor and some normal skin around it to remove possible ‘non-visible’ cancer cells around the tumor (wide local excision or WLE). The study looked at 291 patients who had Mohs surgery and 1,368 patients who had WLE across multiple hospitals to see which surgery was better for overall survival. The results showed that there was no difference in overall survival between the patients who had Mohs surgery and those who had WLE. There was also no difference in side effects between the two surgeries. However, the study had some limitations, such as only a small number of patients having cancer stage data available, which could affect the results. In addition, performing a sentinel lymph node biopsy (SLNB; Sentinel Lymph Node Biopsy ( is important for understanding and treating MCC. In this study, a similar number of patients in both the WLE group and the Mohs surgery group had SLNB (29% vs 26%). However, in the real world, it might be harder to do SLNB with Mohs surgery, which could also affect outcomes. In summary, Mohs surgery can thoroughly check the edges of the removed tissue for cancer and often leads to better cosmetic results. Therefore in some cases, Mohs surgery might be a good choice, but it’s important to have a detailed discussion with your treatment team to decide what’s best for you.


Merkel cell carcinoma (MCC) remains among the most dangerous cutaneous cancers, with a propensity for distant metastases and a strikingly high associated mortality. Treatment has historically relied on wide local excision (WLE), but Mohs micrographic surgery (MMS) remains an alternative surgical technique that allows for flexible surgical margins by utilizing complete intraoperative margin assessment. To compare both techniques, this study analyzes clinical outcomes of patients with primary cutaneous MCC through a national, deidentified health care database.

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