CAPOX vs. FOLFOX for Colorectal Cancer - Real World Outcomes in Ontario, Canada

CAPOX and FOLFOX are widely-used chemotherapy regimens for colorectal cancer (CRC). The superiority of one regimen over the other in a real-world setting (RWE) could have significant clinical implications given their common use, but such RWE is limited. This study analyzed provincial database records of 13,461 Canadian patients treated from 2005-2017. The primary outcomes were rates of Emergency Department visits and/or hospitalizations (ED/H) and overall survival (OS). CAPOX was used less frequently (8.4%) than FOLFOX (91.6%), often in older patients (p< 0.003 for Stage I-III; p< 0.001 for Stage IV). CAPOX recipients had shorter treatment durations (median 15 vs. 20 weeks, p=0.002) and higher unadjusted ED/H rates (60.8% vs. 50.9%, p< 0.001), though this difference was nonsignificant on multivariate analysis (MVA) (HR 1.05 (0.92, 1.20), p = 0.466). Patients receiving CAPOX had worse OS than those on FOLFOX, (5-year OS 70.1% vs. 77.2% (p< 0.001) non-metastatic; 16.6% vs. 33.2% (p< 0.001) metastatic). MVA confirmed inferior OS with CAPOX (HR 1.42, p< 0.001). Other predictors of shorter OS included older age, male sex, comorbidities, rural residence, and lower income. This administrative data is at risk of bias but highlights the need for careful patient selection and informed treatment decision-making.