Cost-minimization analysis of sequence changes between FOLFIRI and FOLFOX6 therapy for advanced colorectal cancer in Japan.

Background: Randomized, controlled trials (RCTs) in 220 patients with advanced colorectal cancer reported no significant differences in survival periods between folinic acid/5-fluorouracil/irinotecan (FOLFIRI) and folinic acid/5-fluorouracil/oxaliplatin (FOLFOX6) therapies, irrespective of the treatment sequence. Based on a literature search, an economic assessment of both treatments given in 1 of 2 sequences (FOLFIRI and FOLFOX6, or FOLFOX6 and FOLFIRI) has not been conducted in Japan.

Objective: The present cost-minimization analysis used a mathematical Markov model to assess health care costs of these 2 treatment sequences from the perspective of National Health Insurance (NHI) in Japan.

Methods: The analysis simulated the expected costs resulting from the influence of treatment sequence in a hypothetical cohort of 10,000 patients with nonresectable advanced colorectal cancer over a period of 100 months using a hypothetical Markov model. Clinical parameters were obtained from the RCTs. Cost parameters included those for physical examination, medication, and personnel. Medication and physical examination costs were based on 2008 NHI drug prices and medical service fees, respectively. Costs were discounted at a monthly rate of 0.4575% (equivalent to an annual rate of 3%). The influence of each parameter (clinical and cost parameters) was assessed using a probabilistic sensitivity analysis by the 10,000-time Monte Carlo simulation.

Results: When FOLFIRI was used as the initial treatment in this analysis, costs to the NHI were reduced. On analysis of the influence of each parameter, the expected reduction in costs, compared with FOLFOX administered as the initial treatment, was significant ( 7,787,828 yen [95% CI, 6,098,517 yen - 9,499,952 yen]).

Conclusions: The findings of this cost-minimization analysis suggest that using FOLFIRI followed by FOLFOX versus the reverse strategy produced cost savings from the perspective of the NHI in Japan. However, differences in adverse-events profiles may warrant treatment adjustments in individual patients.