(SLB-051) Predictors of Genetic Testing Among Patients With Non-Small Cell Lung Cancer Receiving Targeted Therapy

Background: Targeted therapy (TT) is used in the personalized treatment of cancers with specific mutations. They require genetic testing for the selection of the most appropriate treatment.

Objectives: In this study, we aimed to identify predictors of genetic testing among patients with non-small cell lung cancer (NSCLC) using targeted drug therapy.

Methods: We utilized the 2012-2019 SEER-Medicare dataset for this study. Patients aged ≥66 years diagnosed with histologically confirmed primary NSCLC between 2013 to 2017, using targeted drug therapy, enrolled in Medicare A and B for 6 months pre-diagnosis and Medicare A, B, and D during 1 year post diagnosis were included in the study. Any patients with HMO coverage within the study period were excluded. Patients receiving TT within 1 year of diagnosis were identified using HCPCS codes (injectables) and generic name (oral). Genetic testing completed post diagnosis but before the associated treatment (e.g. EGFR for erlotinib and gefitinib) was identified using CPT codes. Possible predictors of genetic testing ascertained included: sociodemographic variables such as age, sex, race, ethnicity, marital status, metropolitan status, and clinical variables such as cancer stage, comorbidity score, and total medical cost. Total medical cost included outpatient, inpatient, prescription drugs and home health services and was categorized in four quartiles (Q1-Q4). Univariate and multivariable logistic regression was used to address study objectives.

Results: In total, 1693 patients were included in the study, among which 51.2% patients had genetic testing before starting the therapy. Most patients were of age groups 66-70 years (32.9%) and had the distant cancer stage (59.3%). Sex, race, and cancer stage were associated with the utilization of genetic testing (male vs female (OR= 0.75, 95% CI 0.61-0.92, p=0.01), Black vs white (OR = 0.50, 95% CI 0.32-0.78, p=0.02), distant vs localized (OR= 2.5, 95% CI 1.64-3.00, p=0.09 respectively.

Conclusions: In this study, about half of patients with NSCLC receiving TT did not complete the associated genetic testing before treatment. Males and Blacks had lower likelihood of completing genetic testing. Interventions targeting gender and racial inequity may improve genetic testing rates and the quality of treatment provided to patients with NSCLC.