[Repeat screening for colorectal carcinoma in a population of asymptomatic individuals after 2 years].

The first stage of the screening of colorectal carcinoma took place in the Bruntál district in 1985-1986. In 1987-1988 this population group of asymptomatic workers was examined repeatedly. After two years an examination of 4512 subjects from a total of 4909 issued tests was made. During the repeated screening programme the return rate of tests was 91.9%. The number of patients with positive occult haemorrhage into faeces was 65 (1.44%). The number of patients with positive oncological disease in the sense of an adenomatous polyp or carcinoma was 18 (0.40%). None of these 18 patients was in the group of patients with positive occult haemorrhage in the first stage of the screening in 1985-1986. Adenocarcinoma was revealed in two instances, once in stage Dukes A and once in stage Dukes B. Another cause of positivity of occult haemorrhage in faeces was diagnosed in 47 cases (1.04%). The frequency of oncologically conditioned positivity of occult haemorrhage in faces declined during screening after two years from the original 0.92% to 0.40%. Both detected carcinomas of the large intestine were revealed at a time which, if further radical treatment is provided, gives hope of satisfactory therapeutic results.