Assessing Oncologists' Adoption of Biomarker Testing in Metastatic Colorectal Cancer Using Real-World Data

Abstract

Background: Despite national guideline recommendations for universal biomarker testing (KRAS, NRAS, BRAF, and mismatch repair and microsatellite instability [MMR/MSI]) in all patients with metastatic colorectal cancer (mCRC), little is known regarding adherence to these recommendations in routine practice. Methods: We retrospectively reviewed patients with mCRC diagnosed between January 1, 2013, and December 27, 2018, from a de-identified electronic health record-derived database. We analyzed disparities in KRAS, NRAS, BRAF, and MMR/MSI testing by race, age, sex, and insurance status using χ2 tests and t tests. We evaluated changes in biomarker testing over time with attention to changes around dates of landmark publications and guideline updates using χ2 tests and Cochran-Armitage tests. Results: A total of 20 333 patients were identified of which 66.6% had test results for any biomarker. Rates of test results for all 4 biomarkers statistically significantly increased over time (P