Rates and Predictors of Chemotherapy Use for Stage III Colon Cancer: a Systematic Review

Despite consensus regarding the benefits of chemotherapy for stage III colon cancer, multiple reports have found significant variations in rates of use. In the current study, the authors attempted to systematically review reports of the community rates at which chemotherapy is administered for stage III colon cancer in the US, and in so doing plan strategies for improving rates of use. A systematic search strategy was undertaken using MEDLINE, Web of Science, and bibliographies to find reports of the rates at which patients with stage III colon cancer receive chemotherapy. A total of 22 studies published since 1990 were identified, with rates of chemotherapy use ranging from 39% to 71%. Age and comorbidity were found to be the most significant patient factors, but studies also found racial/ethnic and socioeconomic disparities in the rates of chemotherapy. Patients treated at teaching hospitals did not clearly receive chemotherapy more often. Oncologists and surgeons who treat a higher volume of colorectal cancer patients were more likely to have chemotherapy initiated in their patients. The authors developed a conceptual model of the process pathway experienced by patients with stage III colon cancer to demonstrate areas of potential underuse of chemotherapy. Nearly half of patients with stage III chemotherapy in the US do not receive chemotherapy. Although many patients are too old or frail to benefit appropriately, for many patients chemotherapy is simply not initiated. Attention needs to be focused on systematic approaches to prevent systems failures that result in underuse. Guidelines regarding chemotherapy use in elderly patients are especially important.