Melanoma of the head and neck: Mohs or wide local excision?
Clinical Applications
Dr. Schwarzenberger is the former physician editor of DermWorld. She interviews the author of a recent study each month.
By Kathryn Schwarzenberger, MD, April 1, 2020
In this month’s Clinical Applications column, Physician Editor Kathryn Schwarzenberger, MD, talks with Ian Maher, MD, about his recent JAAD article ‘Improved overall survival of melanoma of the head and neck treated with Mohs micrographic surgery versus wide local excision.'
Dr. Schwarzenberger: You and your colleagues recently published a very interesting study in which you concluded that survival rates from head and neck melanoma may be improved through treatment with Mohs micrographic surgery (MMS). Can you briefly describe your study and your results here?
Dr. Maher: The study looked at retrospective data from the National Cancer Database (NCDB), which is a database from all American Cancer Society accredited cancer centers. We looked at the all-cause mortality — because that’s the only survival endpoint collected by that database. Our results showed that even correcting for the available confounders, patients undergoing Mohs for melanoma survived as well or better than patients undergoing wide local excision (WLE).
Dr. Schwarzenberger: The survival benefit from MMS was seen primarily in patients with thin melanoma (<0.74 mm) and lentigo maligna melanoma. Do you have any thoughts as to why this is the case?
Dr. Maher: The number of patients with thicker melanomas is smaller and the outcomes are worse with these more aggressive tumors regardless of treatment modality. Thus, it’s harder to detect a small difference in survival. What is salient, is that patients undergoing Mohs did not fare worse in terms of all cause survival regardless of Breslow depth.
Dr. Schwarzenberger: Is it possible that lentigo maligna is biologically a different tumor from superficial spreading melanoma, and if so, do you have thoughts as to how we might better understand this? Could LM overall be a “more benign” type of melanoma?
Dr. Maher: It does appear that lentigo maligna melanomas are slower to invade, but once they achieve a sufficient depth, they will metastasize.
Dr. Schwarzenberger: Your study endpoint looked at overall all-cause mortality. Obviously, this muddies the water somewhat, and it appears you attempted to control for comorbidities. Can you explain to the readers the tool you used and how that helps control for this?
Dr. Maher: Basically, one of the things that the NCDB does track is the Charlson score which is a measure of health status. Correcting for health status there was either a survival benefit for Mohs, or there was no difference between Mohs and WLE.
Dr. Schwarzenberger: Obviously, this study should help MMS gain traction as a good — and perhaps the best — treatment for some melanoma subtypes. What do you think it will take to finally have this treatment recognized as the gold standard for management of melanoma subtypes?
Dr. Maher: I think it will take a randomized controlled trial to test MMS against WLE.
Disclaimer: The views and opinions expressed in this article do not necessarily reflect those of DW.
