Area deprivation index and EGFR-mutated non-small-cell lung cancer.

Abstract

8595 Background: Survival outcomes in patients with non-small-cell lung cancer (NSCLC) have improved in recent decades with availability of immunotherapy and targeted therapies such as inhibitors of mutated epidermal growth factor receptor (EGFR). However, significant disparities in lung cancer outcomes exist, with many patients not offered biomarker testing and subsequent underuse of targeted therapies. Because it is not well known how social determinants of health (SDOH) impact the use of targeted therapies, we conducted a study to determine the association between area deprivation index (ADI) and presence of mutated EGFR in a large electronic health record (EHR) database. ADI is a validated measure of neighborhood socioeconomic deprivation, a SDOH metric. Methods: This retrospective, observational study used Epic Cosmos, a United States database of deidentified data derived from EHR, to measure the association between ADI and EGFR mutations in patients with stage IV NSCLC treated between January 1, 2015 and December 31, 2022. Receipt of EGFR inhibitors (EGFRIs) was used as a surrogate marker for mutated EGFR, as pathology and molecular data for individual patients were not available from aggregate data. Chi square analysis was used to compare ADI between those who did and did not receive EGFRIs. Results: From a total of 6866 patients meeting criteria for inclusion in our analysis, 653 (9.5%) received EGFRIs while 6213 (90.5%) did not. In the EGFR population, 210 (32.2%) were in the top two quintiles of ADI (most deprivation) while 275 (42.1%) were in the bottom two quintiles of ADI (least deprivation). For the non-EGFR population, 3137 (50.5%) were in the top two quintiles while 1373 (22.1%) were in the bottom two quintiles. Patients who received EGFRIs were more likely to be in the bottom two quintiles of ADI compared to those who did not (OR 2.99, 99% CI 2.32-3.84, p<0.0001). To control for confounding variables, this analysis was repeated after stratifying by geography, sex, smoking status, insurance, and race. This difference in ADI between the EGFR and non-EGFR groups persisted within strata of similar patients including White females with a smoking history in the Northeast with Medicare (OR 7.28, 99% CI 1.56-34.01, p=0.0009) and White females with a smoking history in the Midwest with Medicare (OR 4.76, 99% CI 1.19-19.10, p=0.0038). Conclusions: These data suggest that patients with EGFR mutations, as determined by receipt of EGFRIs, were more likely to reside in neighborhoods with less socioeconomic deprivation. Because of limitations posed by our analytic approach, we were unable to determine if there was a direct association between ADI and the molecular profile of NSCLC, or if these findings are primarily related to differential access to care. Nonetheless, the association persisted within strata of similar demographics, suggesting that it is not entirely explained by confounding related to geography, race, sex, or smoking status.