Tumor recurrence of keratinocyte carcinomas judged appropriate for Mohs micrographic surgery using Appropriate Use Criteria

Background: The use of Mohs micrographic surgery (MMS) has increased greatly to treat basal cell and cutaneous squamous cell carcinomas (keratinocyte carcinoma [KC]), and consensus-based Appropriate Use Criteria (AUC) were developed to identify tumors for which MMS is appropriate.

Objective: We sought to compare recurrence rates after different treatments in tumors judged appropriate for MMS.

Methods: We used data from an observational prospective cohort study and retrospectively categorized consecutive tumors as appropriate for MMS according to the AUC. Among appropriate tumors, we used survival analyses to compare 5-year recurrence rates after treatments.

Results: Among tumors appropriate for MMS (N = 1483), adjusted 5-year recurrence rates were 2.9% (range, 1.4-4.3%) after MMS, 5.5% (range, 3.1-7.9%) after excision, 4.0% (range, 0.6-7.2%) after destruction, and 5.9% (range, 1.5-10.2%) after other treatments. In tumors treated only with MMS or excision (the most similar subgroups), the adjusted hazard ratio of 5-year recurrence after MMS was 0.6 (95% confidence interval, 0.3-1.0; P = .06).

Limitations: This study is limited by its uncertain generalizability, lack of randomization, and unmeasured characteristics.

Conclusion: The AUC identified tumors for which recurrence would be less common after MMS than after excision, but the absolute difference in recurrence rates was small.