Retrospective Analysis of the Safety of FOLFOX Compared to CAPOX for Adjuvant Treatment of Stage III Colorectal Cancer in Newfoundland Patients

Background: Capecitabine and oxaliplatin (CAPOX) and infusional 5-fluouracil, folinic acid, and oxaliplatin (FOLFOX) are the two chemotherapy regimens in current clinical use for the adjuvant treatment of colorectal cancer (CRC). Many centers in Newfoundland lack the resources to support the home infusion program required for FOLFOX, leaving CAPOX as the sole treatment option. This study aimed to review if Newfoundland patients receiving CAPOX experience greater treatment-induced toxicities. Methods: A multicenter retrospective cohort study of 93 Stage III CRC patients. The frequency and severity of toxicities, healthcare resource utilization, and treatment completion rates were compared between the two treatment options. Results: Grade 3 diarrhea and grade 1 or 2 nausea/vomiting were more common in CAPOX compared to FOLFOX-treated patients (26.9% versus 2.99%, p = 0.002; 61.5% versus 31.8%; p = 0.048, respectively). Grade 1 or 2 mucositis was more common with FOLFOX (35.8% versus 3.9%, p = 0.002). CAPOX was associated with higher rates of severe toxicity (53.9% versus 25.4%, p = 0.009), while rates of grade 1 and 2 toxicities were not significantly different between groups. CAPOX-treated patients were greater than twice as likely to require emergency department treatment secondary to toxicity (mean 0.692 visits per patient versus 0.313 in FOLFOX patients, p < 0.001) and the proportion of patients that were hospitalized secondary to CAPOX toxicity was greater. Significantly more FOLFOX patients were able to finish their prescribed treatment plans compared to CAPOX patients (89.5% versus 53.8%; p < 0.001). Conclusions: Compared to FOLFOX-treated patients, CAPOX patients are more likely to experience toxicities of greater severity, require emergency services secondary to treatment-related toxicity, and to discontinue therapy. This reflects a reduced standard of care that may decrease patient safety and quality of life.