1174P Sex differences in advanced melanoma in Spain: Results from the prospective real-world study GEM 1801

The incidence of melanoma is increasing in patients (pts) of both sexes, with female pts generally living longer than their male counterparts. This study assessed the sex-based difference in survival of pts with melanoma and the relationship of this difference with pathological features and response to different treatment options in Spain. GEM1801 is a prospective observational study that analyzes the clinical and pathological disease presentation patterns, the different lines of treatment choices and the health outcomes derived from treatments. Here we focus on the sex of pts diagnosed with locally advanced unresectable or metastatic melanoma and their first line (1L) treatment assigned. From Aug 2018 to Dec 2022, 712 evaluable pts were enrolled, 430 males (60.4%) and 282 (39.6%) females. Median age was 67 years (range: 22-95). Most were superficial spreading (42.6% vs 30.5%; p<0.001), being more frequent than other types in females. Primary tumors were more frequently located in the trunk and head in males and in extremities in females (p<0.001). Chronic sun exposure was more frequent among males (12.3% vs 4.6%; p=0.002). Sex led to no statistically significant differences in therapeutic assignment. At data cutoff, the median follow-up was 14.4 m (95% CI: 13.3-16.2). Efficacy is shown in the table.Table: 1174PN, (%)Median PFS (95% CI), monthsp-value CoxMedian OS (95% CI), monthsp-value CoxBRAF + IT Male61 (58.7)20.6 (7.9-NR)0.38135.8 (24.1-NR)0.766BRAF + IT Female43 (41.3)15.3 (6.5-NR)NR (22.9-NR)BRAF + TT Male109 (57.4)9.7 (7.5-12.2)0.00113.9 (11.7-26.2)0.026BRAF + TT Female81 (42.6)16.8 (10.2-27.5)26.1 (21.1-NR)BRAF - IT Male158 (64.6)9.6 (6.6-24.9)0.82729.6 (17.9-47.9)0.865BRAF - IT Female89 (35.4)8.8 (6.5-16.8)23 (18.4-NR)IT = Immunotherapy; TT = Targeted therapy. Open table in a new tab IT = Immunotherapy; TT = Targeted therapy. Melanoma in Spain showed sex-based differences in prevalence, histology type, primary location and risk factors exposure. Therapies are not assigned based on sex. TT in 1L showed significantly better outcomes in females, which may suggest a potential prognostic role of sex useful for therapeutic assignment.