[Population screening for colorectal carcinoma by examining feces for occult hemorrhage].

Colorectal carcinoma is in the western world one of the most frequent deaths from malignant disease. A reliable way how to reduce the mortality from this disease is early diagnosis by screening in the population, the most suitable method being examination of the faeces for occult bleeding. During the last five years in the world literature results of several long-term and well elaborated studies were published focused on screening of colorectal carcinoma by detection of occult haemorrhage in the faeces. There were three American and four European papers from which ensued: 1. In the examined population in the mentioned investigations a reduction of the mortality from colorectal carcinoma was recorded as compared with a control group. 2. In the investigated population also a reduced incidence of advanced colorectal carcinoma was observed (Dukes D). 3. The optimal ratio of sensitivity and specificity was obtained by the HemeSelect test (immunodiagnosis of human haemoglobin) and the combined test (Hemoccult II Sensa + HemeSelect). Large scale examination by these tests was not verified in major population surveys so far. 4. Increasing of the sensitivity of tests using guaiacum resin by rehydration leads to a drop of the specificity of the examination and an enormous increase of coloscopic examinations and the cost of screening. 5. Part of the population with a high risk of colorectal carcinoma should be subjected to large scale examination. The problem remains its correct selection. 6. The adherence of patients to the examination differed in different trials. The increasing number and pretentiousness (dietary restrictions) of the examination reduces proportionately the percentage of cooperating subjects. Examination of the faeces for occult haemorrhage thus can be recommended for national programmes for screening of colorectal cancer.