Cost-effectiveness of screening for colorectal cancer in France using a guaiac test versus an immunochemical test

Objectives: The aim of this study was to compare the cost and the effectiveness of two biennial fecal occult blood screening tests for colorectal cancer: a guaiac nonrehydrated test (G-FOBT) and an immunochemical test (I-FOBT) with the absence of screening. Methods: A Markov model was developed to compare these strategies in a general population of subjects aged 50 to 74 over a 20-year period. Results: Compared with the absence of screening, G-FOBT and I-FOBT were associated with a decrease in colorectal cancer mortality of 17.4 percent and 25.2 percent, respectively. With regard to cost-effectiveness, expressed as cost per life-year gained, I-FOBT was the most effective and most costly alternative. Compared with no screening, G-FOBT and I-FOBT presented similar discounted incremental cost-effectiveness ratios: (sic)2,739 and (sic)2,819 respectively per life-year gained. When compared with G-FOBT, I-FOBT presented an incremental cost-effectiveness ratio of (sic)2,988 per life-year gained. Sensitivity analyses showed the strong influence of the I-FOBT lead time, of the participation rate to screening for I-FOBT, and of the purchase price of the I-FOBT on the discounted incremental cost-effectiveness ratios. Conclusions: Compared with the absence of screening and with G-FOBT, the biennial two-stool immunochemical test can be considered a promising method for mass screening for colorectal cancer.