INTRODUCTION
Due to the high risk of recurrence, excision with clear histological margins is the preferred treatment modality for lentigo maligna (LM) and lentigo maligna melanoma (LMM).1 Conventional wide-local excision (WLE) usually allows for examination of less than 1% of the surgical margin.2 Often, subclinical expansion of abnormal cells results in unanticipated positive margins and requires additional treatment. Mohs micrographic surgery (MMS) employs frozen sections for real-time histological investigation of 100% tumor margin, allowing for same-day margin confirmation prior to reconstruction.1 While surgeons have achieved robust clinical outcomes for LM treated with MMS, performing this treatment for LMM remains controversial and is not standard among all Mohs surgeons. The primary aim of this study was to evaluate survival outcomes in patients treated with MMS and WME for LM/LMM utilizing the National Cancer Institute Surveillance, Epidemiology, and End Results (NCI SEER) database. The secondary aim of this study was to identify significant predictors of MMS utilization in this group.
MATERIALS AND METHODS
Study Sample
Data from the NCI SEER program, collected from 17 cancer registries around the United States from 2000-2019, was retrospectively analyzed. Skin cases (C44.0-C44.9) with a microscopically confirmed diagnosis of LM/LMM (ICD-03: 8742/2 or 8742/3) treated with MMS (facility oncology registry data standards [FORDS] 34-36) or WME (FORDS 45-47) were included in the study. Those cases with incomplete survival data were excluded from our study.
Patient Characteristics
Patient demographics analyzed included age groups, sex, race, ethnicity, marital status, and year of diagnosis. Median household income level, city size, and geographic regions were also included in the study. Tumor characteristics studied included anatomical site, Breslow depth, sequence number, and SEER stage. Surgery types studied included MMS (FORDS 34-36) and WME (FORDS 45-47) indicating gross excision greater than or equal to 1 cm margin. Additional treatments studied included radiation, systemic therapy, and lymph node (LN) examination.
Data from the NCI SEER program, collected from 17 cancer registries around the United States from 2000-2019, was retrospectively analyzed. Skin cases (C44.0-C44.9) with a microscopically confirmed diagnosis of LM/LMM (ICD-03: 8742/2 or 8742/3) treated with MMS (facility oncology registry data standards [FORDS] 34-36) or WME (FORDS 45-47) were included in the study. Those cases with incomplete survival data were excluded from our study.
Patient Characteristics
Patient demographics analyzed included age groups, sex, race, ethnicity, marital status, and year of diagnosis. Median household income level, city size, and geographic regions were also included in the study. Tumor characteristics studied included anatomical site, Breslow depth, sequence number, and SEER stage. Surgery types studied included MMS (FORDS 34-36) and WME (FORDS 45-47) indicating gross excision greater than or equal to 1 cm margin. Additional treatments studied included radiation, systemic therapy, and lymph node (LN) examination.