Abstract B033: Patterns of testing and survival for EGFR mutation and ALK abnormalities in advanced lung cancer at John Peter Smith Hospital

Abstract

Abstract Background: There is paucity of literature regarding outcomes of patients treated for non-small cell lung cancer (NSCLC) at safety-net hospitals (Muslim et al., 2022). John Peter Smith (JPS) hospital is a safety-net hospital serving the needs of underserved population in north Texas. We evaluated testing patterns, prevalence of Epidermal Growth Factor Receptor (EGFR) mutations and Anaplastic Lymphoma Kinase (ALK) fusions in advanced NSCLC at JPS, and outcome measures of 1-, 3- and 5-year overall survival (OS) as compared to patients without these alterations. Methods: We used data from the JPS Oncology Registry and abstracted information from medical records. Eligible patients were diagnosed with stages IIIB-IV NSCLC and treated at JPS from 1/1/2017 to 12/31/2021. Patients were grouped into EGFR+, ALK+, both EGFR- and ALK-, test not ordered/completed (NT). A Kaplan Meier curve was used to assess the difference in post diagnosis survival time across testing status. The log rank test was then performed to assess if the survival distributions were significantly different. To further assess the impact of EGFR and ALK results on patient death three cox proportional hazard models were generated assessing 1-, 3- and 5-year OS. To establish a full model all items collected underwent univariate pre-filtering. All available items were analyzed via a univariate model and items with a p-value of 0.2 or lower were analyzed in our multivariate model using SAS 9.4. Results: 220 patients were included for analysis, 183 (83%) were stage IV. 57% were males. Racial/ethnic distribution included 45% Non-Hispanic Whites (NHW), 32% Blacks, 13% Hispanic Whites (HW) and 10% Asians. 71% were tested for EGFR, ALK, or both. 21 patients (13.7%) were found to have EGFR mutations and 7 patients (4.9%) had ALK fusions. For EGFR, tissue (T) was tested in 134 and blood (B) in 44, both T and B in 23 with concordance in 20. For ALK, T was done in 129, B in 44, 23 had both, with concordance in 21. Testing was inconclusive in 3 (T) for EGFR and 5 (3 T and 2 B) for ALK. Lung was the most common site tested for EGFR with 90 patients followed by liver (8), lymph node (8), and bone (8). Females accounted for 67% of EGFR+ and 57% for ALK+. Asians accounted for 43% of EGFR+ and 28% of ALK+. Median OS in days for study population: 155, EGFR+: 845, ALK+: 1333, both-:162, NT: 105. At 3 years, EGFR+ (HR: 0.427; 95% CI: 0.222, 0.822; p-value: 0.0109) and ALK+ (HR: 0.191; 95% CI: 0.046, 0.795; p-value: 0.0229) showed a significant reduction in the hazard of death compared to both-. NT patients had 1.679 times higher hazard of death when compared to both- (HR: 1.679; 95% CI: 1.206, 2.338; p-value: 0.0021). Similar pattern was seen for EGFR+ for 1 and 5 year OS and for ALK+ at 5 year OS. Conclusions: Prevalence of EGFR and ALK alterations at JPS is similar to nationally reported statistics. Tissue testing is the gold standard for identifying these alterations. 29% of the patients were not tested. Median survival of EGFR+ or ALK+ patients is significantly longer than other cohorts. Citation Format: Vivek Athipatla, James Blackwell, Anna Diaz, Bassam Ghabach, Kalyani Narra. Patterns of testing and survival for EGFR mutation and ALK abnormalities in advanced lung cancer at John Peter Smith Hospital [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B033.