Comparative and cost-effectiveness of oxaliplatin-based or irinotecan-based regimens compared with 5-fluorouracil/leucovorin alone among US elderly stage IV colon cancer patients.

Abstract

Clinical trials have shown a statistically significant disease-free survival benefit of oxaliplatin-based or irinotecan-based combination regimens for stage IV colon cancer. Less is known regarding the comparative effectiveness and cost-effectiveness of these agents among elderly patients. Whether the benefits of these agents justify the additional costs for elderly Medicare recipients is particularly policy relevant after US health care reform. A cost-effectiveness analysis of oxaliplatin-based or irinotecan-based combination therapy versus 5-fluorouracil/leucovorin alone in elderly stage IV colon cancer patients was performed from a US Medicare perspective. Survival and direct medical costs were estimated using Surveillance, Epidemiology, and End Results-Medicare data sets for patients diagnosed from 2002 to 2005 with follow-up through 2007. Incremental cost-effectiveness ratios (ICERs) were calculated as costs per life-year gained, with sensitivity analysis estimating the cost per quality-adjusted life-year (QALY). Median improved overall survival with 5-fluorouracil/leucovorin alone, or irinotecan-based or oxaliplatin-based combination therapy was 0.99, 1.07, and 1.47 life-years, respectively. Costs per life-year gained for oxaliplatin-based or irinotecan-based combination regimens compared with 5-fluorouracil/leucovorin alone were $78,181 and $267,938, respectively. ICERs comparing oxaliplatin-based to irinotecan-based regimens were $40,230 per life-year gained or $160,920 per QALY. Oxaliplatin-based or irinotecan-based combination therapy improves overall survival but also substantially increases direct medical costs compared with 5-fluorouracil/leucovorin alone when used in elderly US patients with stage IV colon cancer. Oxaliplatin-based regimens are more cost-effective than irinotecan-based regimens for treatment of elderly stage IV colon cancer patients in terms of cost per life-year gained, but not in terms of cost per QALY.