LAUSR

The treatment landscape for metastatic colorectal cancer (mCRC) has evolved into a continuum of care with an essential role for biomarkers and molecular subgroups. Treatment guidelines are primarily based on trial results; however, populations and outcomes differ from clinical practice. To support the interpretation of trial results and to assist in tailored patient counseling, we evaluated real‐world treatment patterns and outcomes according to RAS/BRAF status. We included all patients diagnosed with BRAFV600E‐mutated mCRC in 2015–2020, participating in the Prospective Dutch Colorectal Cancer cohort study, plus a 1:2 random selection of patients with RAS‐mutated and double wild‐type mCRC. We evaluated differences in administered lines of treatment (LOTs), local treatment, attrition rates, treatment duration, progression‐free survival (PFS) and overall survival (OS). 178 BRAFV600E‐mutated, 221 RAS‐mutated, and 174 double wild‐type patients were included. Of BRAFV600E‐mutated patients, 26% received ≥3 LOTs, compared to 42% and 47% of the RAS‐mutated and double wild‐type patients, respectively (p = .002). Local treatment was performed in 25% of BRAFV600E‐mutated, 43% of RAS‐mutated, and 49% of double wild‐type patients (p < .001). Median OS from diagnosis was 15.4, 24.1, and 32.6 months, respectively (p < .001) and loss of prognostic value of RAS/BRAF was observed from the 3rd LOT onwards (p = .17 and p = .54). This paper provides a comprehensive overview of the treatment landscape of mCRC per RAS/BRAF status in daily clinical practice. The observed substantial treatment heterogeneity within and between molecular subgroups underlines the importance of collecting real‐world data to address post‐trial knowledge gaps and to optimize individualized counseling for all mCRC patients.