Outcomes of Melanoma In Situ Treated With Mohs Micrographic Surgery Compared With Wide Local Excision

Abstract

IMPORTANCE Melanoma in situ (MIS) is increasing in incidence, and expert consensus opinion recommends surgical excision for therapeutic management. Currently, wide local excision (WLE) is the standard of care. However, Mohs micrographic surgery (MMS) is now used to treat a growing subset of individuals with MIS. During MMS, unlike WLE, the entire cutaneous surgical margin is evaluated intraoperatively for tumor cells.OBJECTIVE To assess the outcomes of patients with MIS treated with MMS compared with those treated with WLE. DESIGN, SETTING, AND PARTICIPANTS Retrospective review of a prospective database. The study cohort consisted of 662 patients with MIS treated with MMS or WLE per standard of care in dermatology and surgery (general surgery, otolaryngology, plastics, oculoplastics, surgical oncology) at an academic tertiary care referral center from January 1, 1978, to December 31, 2013, with follow-up through 2015. EXPOSURE Mohs micrographic surgery or WLE. MAIN OUTCOMES AND MEASURES Recurrence, overall survival, and melanoma-specific survival. RESULTS There were 277 patients treated with MMS (mean [SD] age, 64.0 [13.1] years; 62.1% male) and 385 treated with WLE (mean [SD] age, 58.5 [15.6] years; P < .001 for age; 54.8% male). Median follow-up was 8.6 (range, 0.2-37) years. Compared with WLE, MMS was used more frequently on the face (222 [80.2%] vs 141 [36.7%]) and scalp and neck (23 [8.3%] vs 26 [6.8%]; P < .001). The median (range) year of diagnosis was 2008 for the MMS group vs 2003MMS group vs (1978MMS group vs -2013 for the WLE group (P < .001). Overall recurrence rates were 5 (1.8%) in the MMS group and 22 (5.7%) in the WLE group (P = .07). Mean (SD) time to recurrence after MMS was 3.91 (4.4) years, and after WLE, 4.45 (2.7) years (P = .73). The 5-year recurrence rate was 1.1% in the MMS group and 4.1% in the WLE group (P = .07). For WLE-treated tumors, the surgical margin taken was greater for tumors that recurred compared with tumors that did not recur (P = .003). Five-year overall survival for MMS was 92% and for WLE was 94% (P = .28). Melanoma-specific mortality for the MMS group was 2 vs 13 patients for the WLE group, with mean (SD) survival of 6.5 (4.8) and 6.1 (0.8) years, respectively (P = .77).CONCLUSIONS AND RELEVANCE No significant differences were found in the recurrence rate, overall survival, or melanoma-specific survival of patients with MIS treated with MMS compared with WLE.

Surgical management of localized melanoma: a national cancer database retrospective review

“…Currently, no published clinical trials have examined the role of MMS vs. wide local excision (WLE) for melanoma, despite the fact that the use of MMS for melanoma is increasing in the U.S.A. 1 The limited retrospective data that does exist demonstrates MMS as an equally effective modality for the management of melanoma in situ, lentigo maligna melanoma, and cutaneous head and neck melanomas. 2,3 Currently, MMS is primarily used for in situ and very thin melanomas. Therefore, we sought to examine the role of MMS in localized melanomas, according to the American Joint Committee on Caner (AJCC) cancer staging manual (sixth and seventh editions).…”

Is melanocyte density our last hope? Comparison of histologic features of photodamaged skin and melanoma in situ after staged surgical excision with concurrent scouting biopsies

“…However, accumulating evidence suggests that 5 mm margins may be inadequate as the tumor may extend beyond the visible pigmented lesion. The disadvantages of traditional Mohs micrographic surgery include the use of frozen sections, and one study found no significant difference in 5‐year recurrence rates between MIS treated with Mohs vs wide local excision …”

“…Given the necessity for increased margins in treating MIS, using a staged excisional technique such as the “slow Mohs” approach is advantageous since the entire margin is assessed. Therefore, physicians are able to discern exactly where additional excision of affected tissue needs to be performed, and it may lead to better cosmetic outcomes, which is important since the lentigo maligna subtype frequently occurs on the face . Scouting biopsies, which serve as a negative internal control, performed concurrently with surgical excision of MIS can be useful as a reference in comparing benign, sun‐damaged skin with equivocal margins to aid in determining if additional excisions should be taken.…”

Mohs micrographic surgery versus wide local excision for melanoma in situ: analysis of a nationwide database

“…However, their study focused on invasive lesions, compared to MIS for the present study. Nosrati and colleagues performed a retrospective cohort study of 662 patients with MIS. There were 385 cases of WLE and 277 cases of MMS.…”

“…Few studies have directly compared WLE versus MMS techniques for the surgical management of MIS. Nosrati et al performed a retrospective study of 662 patients with MIS and did not find a significant difference in recurrence rates, overall survival, or melanoma‐specific survival between the two groups. Using a nationwide database, we sought to compare the survival outcomes of WLE versus MMS techniques for MIS.…”