Impact of Lung Biomarker Testing on Out-Of-Pocket Costs for Metastatic Non–Small-Cell Lung Cancer

Background: Biomarker testing in metastatic non–small lung cancer (NSCLC) is critical for appropriate treatment. Claims-based datasets offer real-world information on the use and cost of biomarker testing. Materials and Methods: We used 2013-2021 data from Optum's de-identified Clinformatics Data Mart Database. Eligible patients were adults with ≥ 2 NSCLC diagnosis codes and ≥ 2 claims of a secondary malignant neoplasm. We excluded patients with another primary or no continuous insurance coverage 12 months prior and 6 months after diagnosis. We assessed out-of-pocket (OOP) costs. Descriptive statistics were used to assess testing rates, and multivariable analyses (MVA) were performed to assess factors associated with testing. Results: We identified 4377 patients with metastatic NSCLC (mean age 60 years (SD 8.33), 49.6% female, 76.7% former smokers). Testing rates within 2 months of diagnosis increased from 58.15% in 2013 to 69.96% in 2021. On MVA, biomarker testing was associated with younger age, nonsmokers, Mountain geographic region, and point-of-service insurance plans. Biomarker testing was associated with a median OOP cost of $98 (IQR: $43.87-$306.58). Patients who underwent biomarker testing had a median total OOP cost of all services within 6 months of diagnosis of $3560.20 (IQR: $1538.37-$6199.44) compared to $1979.58 (IQR: $725.75-$4003.06) for those who did not undergo biomarker testing. Conclusions: Using claims data, we find that most patients with metastatic NSCLC undergo biomarker testing early in their treatment course (0-60 days), suggesting that testing is appropriately being obtained early on in their treatment course, but this testing is associated with substantially higher overall OOP costs to patients.