Previous therapy and the recurrence rate of basal cell carcinoma after Mohs surgery: a meta-analysis

Mohs micrographic surgery (MMS) for basal cell carcinoma (BCC) is indicated for patients at high risk of recurrence; other therapies, including standard surgical excision, cryotherapy, electrodesiccation and curettage, and radiotherapy, are used in low-risk BCC and in patients who cannot undergo surgery. However, in the case of recurrence following treatment with any of these methods, MMS is indicated. This study aimed to examine how preoperative treatment before MMS affects the recurrence rate after surgery. We conducted a meta-analysis to compare the recurrence rates of primary BCC and previously treated BCC in patients undergoing MMS, with a 5-year follow-up. The secondary outcomes were the recurrence rate after MMS based on previous radiation therapy status, mean time to recurrence, and number of cases undergoing more than one stage of MMS. The recurrence rate in the previously treated group was 2.44 times greater than that of the primary BCC group. In the previous treatment group, the patients who underwent previous radiation showed a 2.52-fold higher recurrence rate than those with no previous radiation therapy. However, there was no significant difference in the mean time to recurrence and the number of cases requiring MMS > 1 stage between the previously treated and non-treated groups. Patients with previously treated BCC, especially those treated using radiation, had a higher likelihood of recurrence.