Biomarkertesting in metastatic colorectal cancer (mCRC): 2015-2024 trends in the United States (US) community oncology setting.

Abstract

e15573 Background: The availability of biomarker-targeted therapies has changed the treatment landscape for mCRC. Starting in 2009, cetuximab was approved as a biomarker-driven agent for KRAS wild-type CRC. Within the past decade, more molecular targeted therapies for mCRC have become available, and clinical guidelines increasingly recommend biomarker testing (i.e., BRAF , KRAS , HER2 , NRAS, MMR, MSI, NTRK , RET ) to guide treatment. Given the rapidly evolving treatment landscape, this analysis evaluated biomarker testing trends among patients with mCRC within a large database of community oncology facilities in the US. Methods: This analysis was a retrospective study utilizing structured data from an oncology-specific electronic health records database within The US Oncology Network and non-Network practices. Adult patients diagnosed with mCRC from January 2015 to December 2024 were included. Evidence of testing for the following biomarkers was evaluated at any time on or after metastatic diagnosis: BRAF , KRAS , HER2 , NRAS , MMR , MSI , NTRK , and RET. Results: The cohort included 27,548 patients with mCRC. Median age at diagnosis was 64 years, and 69% of patients were de novo metastatic. Testing rates for KRAS were between 90% and 98%, corresponding with the availability of cetuximab-based regimens over the study period. In 2020, following the approval of tucatinib, HER2 testing rates increased from 32%-66% prior to 2019 to 89%-93% after 2020. BRAF testing rates also increased to 90%-96% after 2017, following the approval of encorafenib plus cetuximab combination therapy for BRAF-mutated mCRC in 2018. NTRK testing rates (21%-42%) showed improvement over the study period, with the highest proportion of patients tested in 2024 corresponding to the accelerated approval of repotrectinib for in the same year. Similarly, RET testing (25%-89%) peaked in 2023 following breakthrough therapy designation for selpercatinib in late 2022. Conclusions: As new targeted therapies have emerged in recent years, biomarker testing rates for mCRC have rapidly increased in the community oncology setting. NTRK or RET rearrangements are infrequent in advanced CRC, with lower testing rates for these genes within the study period. However, as this study leveraged structured data only, actual rates of testing may be even higher for some biomarkers. Despite overall high testing rates, more research is needed to identify remaining barriers to access for treatment-guided biomarker testing. Testing rates by year and biomarker. Biomarker Testing Rates (%) 2015n=2,325 2016n=2,501 2017n=2,819 2018n=2,651 2019n=2,772 2020n=2,744 2021n=2,880 2022n=3,068 2023n=2,926 2024n=2,862 BRAF 50 52 68 93 96 96 96 94 94 90 KRAS 98 98 98 98 97 97 97 96 95 90 HER2 39 32 35 46 66 92 93 92 91 89 NRAS 71 85 82 92 95 96 96 95 94 89 MMR 51 60 86 94 94 95 95 96 96 96 MSI 73 74 95 96 96 98 98 98 98 98 NTRK 34 24 21 21 27 29 35 38 39 42 RET 35 26 25 27 34 38 50 68 89 64