Survival benefit for patients with colorectal cancer detected by population-based screening program using an immunochemical fecal occult blood test

: The effectiveness of screening for colorectal cancer by an immunochemical fecal occult blood test was investigated by comparing the survival time of 194 screen-detected colorectal cancer subjects (screen-detected group) with that of 352 routinely diagnosed subjects (control group). The rate of Dukes' A cancers was significantly higher in screen-detected group than in the control group (43.8% vs 16.8%, p<0.0001), whereas that of Dukes' D cancer was the opposite (5.7% vs 21.3%, p<0.0001). The survival rate for screen-detected group was higher than that for the control group (Kaplan-Meier method, p<0.0001). By a proportional hazard model with adjustment for prognostic factors except stage, the risk ratio of death from colorectal cancer was 0.40 (p=0.0007) for screen-detected group versus the control group. Therefore, the screening was suggested to be effective in survival benefit, although there might be potential biases inherent in observational studies.