CAPOX associated with toxicities of higher grade but improved disease-free survival when compared with FOLFOX in the adjuvant treatment of stage III colon cancer.

Abstract Introduction/Background Adjuvant treatment of colon cancer relies on fluoropyrimidine-containing regimens as the intravenous formulation, 5-FU, or its oral prodrug, CA, combined with oxaliplatin (FOLFOX and CAPOX). There is currently no clinical trial comparing the 2 regimens; however, both are considered standard of care treatment options. Materials and Methods We performed a retrospective chart review comparing average relative dose intensity (ARDI), percentage of intended total dose (PITD), overall survival (OS), DFS, and toxicity profiles of these regimens. The patients (n = 176) received either modified FOLFOX6 (n = 93) or CAPOX (n = 83). Results Oxaliplatin ARDI (80.72% vs. 87.11%; P  = .0033) and PITD (70.09% vs. 88.11%; P  = .0013) was significantly lower in those treated with CAPOX compared with FOLFOX. CA ARDI (87.10% vs. 93.60%; P P  = .0006) was significantly lower than 5-FU dosing. Patients treated with CAPOX had more ≥ Grade 2 toxicities and trended toward more dose-limiting toxicities. Survival analysis demonstrated a trend toward improved OS with CAPOX (hazard ratio [HR], 0.4741; 95% confidence interval [CI], 0.1660-1.354; P  = .1663) and improved DFS with CAPOX (HR, 0.4949; 95% CI, 0.2512-0.9749; P  = .0420). Multivariate analysis demonstrated similar results with CAPOX being associated with a trend toward improved OS (HR, 0.396; 95% CI, 0.110-1.429; P  = .1571) and DFS (HR, 0.458; 95% CI, 0.210-1.001; P  = .0504). Conclusion Patients receiving CAPOX had significantly lower ARDI and PITD compared with FOLFOX, but showed trends toward improved outcomes when treated with CAPOX in the adjuvant setting when compared with FOLFOX.