Suboptimal Completion Rates, Adverse Events, Costs, Resource Utilization, and Cost Impact of Noncompletion in Oral Adjuvant Capecitabine–Based Chemotherapy in Patients With Early-Stage Colon Cancer

Background: Suboptimal completion of chemotherapy, which may involve reduced patient adherence, remains a serious issue and leads to reduced treatment efficacy. This study assessed the completion rates, risk factors for noncompletion, and cost impact for noncompletion in patients on capecitabine monotherapy (Cape) or capecitabine with oxaliplatin (CAPOX) for the adjuvant treatment of early-stage colon cancer. Methods: Patients with a diagnosis of early-stage colon cancer between April 2013 and March 2017 were retrospectively identified. Treatment completion was evaluated. Multivariate logistic regressions analyses were used to assess the baseline factors associated with noncompletion. Adverse events, costs, healthcare resource utilization, and cost impact for noncompletion were investigated. Results: A total of 673 patients met the eligibility criteria, of which 382 (57%) were treated with Cape and 291 (43%) with CAPOX. The overall completion rate for adjuvant therapy was 40% (Cape 46%; CAPOX 33%). Noncompletion was associated with CAPOX treatment and higher healthcare costs within 6 months prior to chemotherapy. The 6-month unadjusted total healthcare costs were $44,444 for Cape and $71,247 for CAPOX. The nonchemotherapy costs were 41% higher for noncompleters than completers in both treatment groups (P = .002). Conclusions: The real-world completion rates for adjuvant capecitabine–based chemotherapy in early-stage colon cancer patients are low. Noncompletion of therapy is associated with higher baseline healthcare costs. The nonchemotherapy costs are significantly higher in noncompleters than completers, highlighting the financial burden of managing adverse events and preexisting comorbidities, which may lead to early discontinuation of therapy. Effective strategies to optimize completion of oral chemotherapy may consider adherence monitoring.