Association of Treatment Facility Characteristics With Overall Survival After Mohs Micrographic Surgery for T1a-T2a Invasive Melanoma

Abstract

elanoma is one of the most common cancers in the US, with 106 110 incident cases estimated to be diagnosed in 2021. 1 Although the standard therapy for localized invasive melanoma is wide local excision, Mohs micrographic surgery (MMS) has been increasingly used as an alternative excisional approach, [2][3][4] with a recent study reporting that 7.9% of surgical melanoma cases in 2016 were excised using MMS. 5 Mohs micrographic surgery offers the advantage of complete margin evaluation during the procedure while potentially limiting healthy tissue removal. Such complete margin evaluation is especially helpful in the case of facial tumors, for which National Comprehensive Cancer Network guidelines state that margins may be reduced for anatomic considerations, or tumors with clinically indistinct borders, such as lentigo maligna melanoma, for which appropriate margins may be difficult to determine clinically. 2,6 Recent work suggests that treatment of early-stage (T1a-T2a category) melanoma with MMS is associated with a modest survival advantage compared with traditional wide local excision. 7 An additional consideration for the more technically complex MMS for melanoma procedure is how effectively it can be applied across centers. Although studies of resections for other cancers have reported that facility-level factors are associated with patient outcomes, it is not yet established how such factors may IMPORTANCE Early-stage melanoma, among the most common cancers in the US, is typically treated with wide local excision. However, recent advances in immunohistochemistry have led to an increasing number of these cases being excised via Mohs micrographic surgery (MMS). Although studies of resections for other cancers have reported that facility-level factors are associated with patient outcomes, it is not yet established how these factors may affect outcomes for patients treated with Mohs micrographic surgery.OBJECTIVE To evaluate the association of treatment center academic affiliation and case volume with long-term patient survival after MMS for T1a-T2a invasive melanoma. DESIGN, SETTING, AND PARTICIPANTSIn a retrospective cohort study, 4062 adults with nonmetastatic, T1a-T2a melanoma diagnosed from 2004 to 2014 and treated with MMS in the National Cancer Database (NCDB) were identified. The NCDB includes all reportable cases from Commission on Cancer-accredited facilities and is estimated to capture approximately 50% of all incident melanomas in the US. Multivariable survival analyses were conducted using Cox proportional hazards models. Data analysis was conducted from February 27 to August 18, 2020. EXPOSURES Treatment facility characteristics.MAIN OUTCOMES AND MEASURES Overall survival. RESULTSThe study population included 4062 patients (2213 [54.5%] men; median [SD] age, 60 [16.3] years) treated at 462 centers. Sixty-two centers were top decile-volume facilities (TDVFs), which treated 1757 patients (61.9%). Most TDVFs were academic institutions (37 of 62 [59.7%]). On multivariable analysis, treatment at an aca...

Mohs Micrographic Surgery for Melanoma—Do Outcomes Vary Among Treatment Facilities?

“…7 Locally recurrent melanomas are also significantly more likely to be associated with subclinical spread or require complex reconstruction with flaps or grafts. 8 Cheraghlou et al 1 show that a substantial number of melanomas on the trunk and extremity were treated with MMS at all facilities, but particularly at low-volume or nonacademic facilities where more than 70% of all melanomas treated with MMS were not on the head and neck, compared with approximately 50% in high-volume or academic centers. Mohs micrographic surgery may not have been necessary for many of these trunk and extremity melanomas.…”

“…Cheraghlou et al reviewed data from the National Cancer Database (NCDB) to evaluate whether overall survival differs when patients with T1a-T2a melanomas are treated with Mohs micrographic surgery (MMS) in high- vs low-volume or academic vs nonacademic facilities. Analysis was limited to this population based on previous work, which reported improved overall survival among patients with T1a-T2a melanoma treated with MMS compared with wide local excision (WLE) .…”

“…Despite these limitations, Cheraghlou et al raise several important questions. First, can indications for the use of MMS for melanoma be standardized?…”

“…Second, can the minimum number of cases be determined to develop competency for MMS for melanoma? Cheraghlou et al defined high-volume, top-decile facilities as those where MMS for melanoma was performed at least 8 times annually, ranging from 8.00 to 127.29 with a median of 15.7 (interquartile range, 10.5-26.25). Patients with T1a-T2a melanoma were 20% less likely to die when MMS was performed in top-decile facilities (HR, 0.795; 95% CI, 0.648-0.977; P = .03).…”

“…The association between higher volumes and improved outcomes is consistent with studies assessing outcomes of patients with other cancers, as well as for nonmetastatic and metastatic melanomas . Cheraghlou et al do not address how many cases a surgeon performing MMS must conduct to be competent in treating melanoma. The Accreditation Council for Graduate Medical Education requires fellows to perform a minimum of 500 MMS cases during a 1-year Micrographic Surgery and Dermatologic Oncology fellowship .…”