Background Previous literature demonstrates correlations between comorbidities and failure to complete adjuvant chemotherapy. Frailty and socioeconomic disparities have also been implicated in affecting cancer treatment outcomes. This study examines the effect of demographics, comorbidities, frailty, and socioeconomic status on chemotherapy completion rates in colorectal cancer patients. Methods This was an observational case-control study using retrospective data from Stage II and III colorectal cancer patients offered chemotherapy between January 01, 2013 and January 01, 2018. Data was obtained using the cancer registry, supplemented with chart review. Patients were divided based on treatment completion and compared with respect to comorbidities, age, Eastern Cooperative Oncology Group (ECOG) score, and insurance status using univariate and multivariate analyses. Results 228 patients were identified: 53 Stage II and 175 Stage III. Of these, 24.5% of Stage II and 30.3% of Stage III patients did not complete chemotherapy. Neither ECOG status nor any comorbidity predicted failure to complete treatment. Those failing to complete chemotherapy were older (64.4 vs 60.8 years, P = .043). Additionally, those with public assistance or self-pay were less likely to complete chemotherapy than those with private insurance ( P = .049). Both factors (older age/insurance status) remained significant on multivariate analysis (increasing age at diagnosis: OR 1.03, P =.034; public insurance: OR 1.84, P = .07; and self-pay status: OR 4.49, P = .03). Conclusions No comorbidity was associated with failure to complete therapy, nor was frailty, as assessed by ECOG score. Though frailty was not significant, increasing age was, possibly reflecting negative attitudes toward chemotherapy in older populations. Insurance status also predicted failure to complete treatment, suggesting disparities in access to treatment, affected by socioeconomic factors.
A biological perspective on the selection of stage II colorectal cancer patients for adjuvant chemotherapy