DISP-04. SEX DIFFERENCES IN LUNG CANCER BRAIN METASTASES ADVERSE EVENTS

Abstract While sexual dimorphism is evident among adverse events (AEs) in response to treatments for many cancers, including brain tumors, little is known about sexual dimorphism among AE in brain metastases (BrM). As over 50% of BrM cases arise from lung cancer (LC), we examined sex differences in AEs associated with LC-BrM among individuals in the SEER-Medicare dataset aged ≥66 years at the time of LC diagnosis. Multivariable logistic regression models adjusted for demographic variables and Elixhauser comorbidity scores were used to analyze sex differences in AEs among individuals with BrM derived from primary LC. Analyses were stratified by the following histological subtypes: small-cell, adenocarcinoma, squamous cell carcinoma, or other non-small cell carcinomas. Additional variables analyzed included BrM treatment, age at BrM diagnosis, and year of diagnosis (at or before 2013/after 2013) to account for the introduction of targeted therapies. Differences in AE profiles, based by sex, in individuals diagnosed with LC-BrM were observed. Females diagnosed after 2013 with either small-cell, squamous cell, or other non-small cell carcinoma BrMs were more likely to experience headaches compared to males. Males diagnosed after 2013 with adenocarcinoma were more likely to experience brain herniation compared to females. Additionally, females aged 76 and older with small-cell BrM demonstrated an elevated risk of developing vision difficulties relative to males, whereas no significant sex difference observed in those under 76 years. Risk of most AEs decreased across all histological subtypes with receiving treatment after BrM diagnosis when compared to no treatment. This study underscores the existence of sex-specific differences in AEs among individuals aged 66 years and older diagnosed with LC-BrM. The AEs observed varied across histological subtypes, age cohorts, year of diagnosis, and treatment. Notably, receipt of treatment demonstrates consistent reduction in AE risk across all histological subgroups, underscoring the therapeutic benefit of treatment.