Mohs micrographic surgery (MMS) represents an alternative approach to traditional wide margin excision (WME) in select patients with early-stage invasive melanoma without compromising patient survival, according to research published in JAMA Dermatology.
Although current guidelines for treatment of melanoma recommend surgery with WME, use of MMS has increased in recent years as an alternative to WME, as it allows for less tissue removal during excision. Researchers aimed to evaluate the association between the two surgical excision strategies and overall survival in patients with stage I invasive melanoma as classified by the American Joint Committee on Cancer AJCC Cancer Staging Manual, 8th edition (AJCC-8). Factors governing the use of MMS over WME were also explored.
A total of 70,319 patients (47.7% female) from the Commission on Cancer’s National Cancer Database were included in the retrospective cohort study. Approximately 95.4% of patients received WME, compared with 4.6% who received MMS. After controlling for covariates such as clinical and tumor factors, patients treated with MMS experienced improved overall survival compared with those treated with WME (hazard ratio [HR], 0.86; 95% CI, 0.76-0.97; P =.02). Analysis of propensity score-matched cohorts of patients revealed similar trends, with patients receiving MMS exhibiting improved overall survival compared with those treated with WME (HR, 0.82; 95% CI, 0.68-0.98; P =.03).
Several factors were associated with the choice of excision strategy used. MMS was more likely to be used in the oldest patients (≥75 years) compared with younger patients (<55 years; odds ratio [OR], 1.16; 95% CI, 1.04-1.30; P =.006), and in black patients compared with white patients (OR, 1.87; 95% CI, 1.07-3.28; P = .03). In addition, academic facilities were more than twice as likely to use MMS as nonacademic facilities (OR, 2.03; 95% CI, 1.88-2.18; P <.001). Men were less likely to receive MMS than women (OR, 0.91; 95% CI, 0.85-0.99; P =.02), and MMS was used less frequently in more aggressive subtypes of melanoma.
The researchers noted the lack of access to data on recurrence or re-excision as a limitation of the study. Further investigation is needed to determine whether MMS has the ability to provide lower recurrence rates with less tissue removal.
“In this analysis of a large sample of early-stage invasive melanomas, we found that treatment with MMS was associated with a modest survival advantage compared with treatment with traditional WME,” the researchers concluded. “These data suggest that MMS is an effective approach compared with WME for AJCC-8 stage I invasive melanoma.”
Cheraghlou S, Christensen SR, Agogo GO, Girardi M. Comparison of survival after Mohs micrographic surgery vs wide margin excision for early-stage invasive melanoma [published online September 25, 2019]. JAMA Dermatol. doi:10.1001/jamadermatol.2019.2890