Mohs micrographic surgery (MMS) may be a viable alternative to wide margin excision (WME) in selected patients with early-stage invasive melanoma, according to a retrospective cohort study.

In the study, which was published in JAMA Dermatology, patients who underwent MMS had a “modest survival advantage” when compared with those who were treated with WME, the approach recommended for treatment of invasive melanoma without nodal or extralymphatic metastases in national guidelines, reported the investigators.

“We sought herein to investigate the association of the type of surgical excision – WME or MMS – with overall survival for cases of American Joint Committee on Cancer Cancer Staging Manual 8th edition (AJCC-8) stage I invasive melanoma,” wrote Shayan Cheraghlou, of Yale University, New Haven, Conn., and colleagues.

The researchers identified a total of 70,319 patients diagnosed with stage I invasive melanoma between Jan. 1, 2004, and Dec. 31, 2014. Data were collected from the National Cancer Database, including 3,234 (4.6%) and 67,085 (95.4%) patients who underwent MMS and WME, respectively. The median age of patients in the cohort was 57 years; 47.7% were female, and almost 97% were white.

In the survival analysis, the team adjusted for clinical and tumor-specific variables and conducted a matched analysis using propensity scores. The primary outcome measured was overall survival.

After analysis, the researchers found that MMS was associated with modestly better overall survival when compared with WME after adjustments (hazard ratio, 0.86; 95% confidence interval, 0.76-0.97). In the propensity score–matched analysis, a similar modest survival advantage was seen for patients who underwent MMS (hazard ratio, 0.82; 95% CI, 0.68-0.98).

“Significant differences in treatment practices based on the treatment facility were noted, with academic facilities more than twice as likely as nonacademic facilities to use MMS,” they wrote.

The researchers acknowledged a key limitation of the study was the use of a convenience sample, as opposed to a population-based sample. As a result, the generalizability of the findings may be limited to certain treatment facilities.

“These data suggest that MMS is an effective approach compared with WME for AJCC-8 stage I invasive melanoma,” they concluded.

No funding sources were reported. The authors reported having no conflicts of interest.

SOURCE: Cheraghlou S et al. JAMA Dermatol. 2019 Sep 25. doi: 10.1001/jamadermatol.2019.2890.