Cost-effectiveness of adjuvant therapy for treatment of stage II colon cancer in patients with diabetes.

Abstract

421 Background: The decision to treat stage II colon cancer patients with adjuvant chemotherapy involves assessment of life expectancy, risk for recurrent disease, and the potential benefit and likelihood of adverse effects from treatment. This is a challenging task, particularly for patients with pre-existing chronic illnesses such as diabetes, which may increase side effects and potentially lessen response to chemotherapy. Methods: We use the Archimedes Model to analyze cost effectiveness of adjuvant therapy in stage II colon cancer patients with pre-existing diabetes. The Archimedes Model is a large-scale, integrated mathematical model of human physiology, diseases, and healthcare systems, including pathways relating to diabetes, cardiovascular disease, and cancers of the breast, lung, and colon. The colon cancer model is built using the SEER, ACCENT databases and meta-analyses of clinical trials. Costs relating to colon cancer, diabetes and its complications are based on Medicare reimbursement rates. We simulate a trial in which stage II colon cancer patients are subjected to two treatment strategies: no treatment vs. adjuvant chemotherapy by FOLFOX regimen. We report incremental cost-effectiveness ratio (ICER), measured by cost per quality-adjusted life year (QALY) gained, of adjuvant therapy compared with no treatment. Results: Cost effectiveness is strongly dependent on a patient's tumor profile, age and duration of diabetes. For instance, adjuvant therapy saves ∼0.2 QALYs per person in stage IIA patients who are 75 and older and have been diagnosed with diabetes >10 years, at an ICER of >$150,000/QALY gained. In contrast, it saves 1.1 QALYs per person in stage IIB patients aged 60-65, recently diagnosed with diabetes, at an ICER of <$30,000/QALY gained. Results are sensitive to assumptions on efficacy and side effects of chemotherapy in diabetic patients, as well as cost of adjuvant therapy. Conclusions: The current study suggests that the decision to proceed with adjuvant chemotherapy requires careful assessment of severity of diabetes in stage II colon cancer patients with pre-existing diabetes. No significant financial relationships to disclose.