Author’s Disclosure Block: Kimberly Papp, none; Samuel Baugh, none; Ezekiel Weis, none; Robert Goldberg, none; Kelsey Roelofs, Dr. Roelofs is a consultant for Amgen.

Abstract Body
Purpose: To investigate the rate of transformation of eyelid lentigo maligna (LM) to invasive melanoma and to assess the impact of surgical management on disease course and survival. Study Design: Analysis of de-identified Surveillance, Epidemiology, and End Results (SEER) database. Methods: Data was pooled from 17 research registries spanning 2000 – 2020. Patients with a primary site of “eyelid” and diagnosis of LM and/or any malignant melanoma subtype (MM) were included. Group 1 had in situ (LM) disease only, Group 2 had an initial in situ diagnosis followed by MM, and Group 3 had MM without prior LM. Eyelid data were compared to LM/MM elsewhere on the face. Results: Data from 3,403 unique patients were included (Group 1: 2,061, Group 2: 118, and Group 3: 1,224). Comparing Groups 1 and 2 enabled identification of patient factors that predicted progression of LM to MM. There were no significant differences between Group 1 and 2 regarding sex (p = 0.954) or age (p = 0.601). Group 2 had a longer follow up time (10.92 vs 7.36 years, p < 0.001) and were more likely to be white (94.07% vs 87.24%, p = 0.041) and have an annual income < $75,000 (57.63% vs 48.76%, p = 0.075).Patientswho underwent surgical excision for eyelid LM were younger (69.17 vs 72.70 years, p < 0.001), more likely to be white (88.56% vs 81.02%, p < 0.001), and have longer time to follow up (7.77 vs 6.04 years, p < 0.001), compared to patients who did not undergo surgery.Patients with eyelid LM who underwent surgical resection were less likely to develop melanoma (4.78% vs 9.85%, p < 0.001). On multivariate analysis, not receiving surgery (OR: 2.891, p < 0.001), longer follow up time (OR: 1.153, p < 0.001), and white race (OR: 0.452, p = 0.0487) were significant predictors for development of MM. While surgery did not impact disease-specific mortality amongst patients with eyelid LM (p = 0.1), when cases of LM arising elsewhere on the face (62,246 patients) were included, a small but significant effect was demonstrated (15-year disease-specific survival: 96.1% vs 94.7%, p = 0.018). Conclusions: Surgical resection of eyelid LM carries a relative risk reduction of 51.5% and an absolute risk reduction of 5.08% of developing MM. These findings are relevant for counseling patients with eyelid LM.