[Lesions detected in a colorectal cancer screening program in the Basque Country: first round (2009-2011)]

Colorectal cancer (CRC) is a major public health problem due to its incidence and mortality. In May 2008, the Basque Country approved the implementation of a population-based colorectal cancer screening program, using the immunochemical fecal occult blood test (FOBT), in persons aged 50-69 years. Patients with a positive result were invited to undergo colonoscopy with sedation.

To describe the main results of the first round of the CRC screening program with FOBT (2009-2011) in terms of the detection rates and positive predictive value (PPV).

Retrospective study of participation rates and colonoscopic findings in persons with a positive FOBT result.

Invitations to attend screening were sent to 230.505 persons. A total of 148.249 FOBT tests were processed. The mean participation rate was 64.3% (95% CI: 64.1-64.5) and was higher in women than in men. The FOBT test was positive in 6.7% (95% CI: 6.6-6.8). Positive results were more frequent in men. Among persons with a positive result, colonoscopy was performed in 93.1%. There were significant differences between women and men in the detection rate of high-risk adenomas (OR: 0,45 95% CI 0,41-0,49), which, as with CRC (OR: 0,80 95% CI 0,66-0,96), were more frequent in men. The PPV for adenoma of any type was significantly higher in men (72.4 95% CI, 71.2-73.5) than in women (48.8% 95% CI 47.2-50.5), with differences by age group and type of adenoma.

Participation rates and detection of advanced lesions and CRC were high. Because men have a higher risk of developing CRC, efforts should be made to increase their participation. The impact of the CRC screening program should be evaluated in the medium to long term.