Cost-Effectiveness of Adjuvant FOLFOX Therapy for Stage III Colon Cancer in Japan Based on the MOSAIC Trial

Objective: To evaluate the cost-effectiveness of adjuvant FOLFOX therapy versus 5-fluorouracil/leucovorin (FU/LV) for patients with stage III colorectal cancer. Methods: We performed the cost-effectiveness of FOLFOX compared with standard FU/LV treatment by the retrospective analysis of patient-level data from the randomized controlled Multicenter International Study of Oxaliplatin, 5-Fluorouracil, and Leucovorin in the Adjuvant Treatment of Colon Cancer (MOSAIC) trial. Predicted mean time spent in each disease state was calculated by our statistical model, which takes into account the cure rate and treats death from causes other than colon cancer as a competing risk. We performed this analysis from the perspective of the health-care payer. Using a time horizon of 30 years, both cost and effectiveness were discounted by 3% per year. Results: Estimated cure rates for colon cancer were 0.715 (FOLFOX) and 0.622 (FU/LV). Estimated medical costs of FOLFOX were JPY 3.1 million (USD 34,000) compared with JPY 1.9 million (USD 22,000) of FU/LV. The mean estimated quality-adjusted life- year was 9.83 with FOLFOX and 9.07 with that of FU/LV. The incremental cost-effectiveness ratio of FOLFOX was JPY 1.5 million (USD 17,000) per quality-adjusted life-year compared with FU/LV, which was supported by sensitivity analysis. Even if we assume that Japanese outcomes were better than those reported by the MOSAIC trial, which would reduce the difference between cure rates for each treatment to 5%, the incremental cost-effectiveness ratio remained below 5.0 million (USD 56,000) per quality-adjusted life-year. Conclusions: Adjuvant FOLFOX is a cost-effective treatment for stage III colon cancer in Japan compared with FU/LV therapy. Even when parameters were changed to reflect smaller improvements with FOLFOX, the conclusion is the same.