Abstract
Colorectal cancer is a frequent cause of oncological morbidity and mortality. It is the second most common cancer in Europe (13.0%) almost matching the frequency of lung cancer, the most widespread malignancy (13.2%). In European Union countries colorectal cancer is the most frequent tumour. Colorectal cancer is also the second most common cause of cancer death in Europe accounting for 11.9% of cancer-related mortality (4). In 20% of colorectal cancer patients, genetic background exists. However, the discovered genetic mutations related to high lifetime risk of colorectal cancer account only for 5-6% of colorectal cancer cases (27). The two main hereditary cancer syndromes involving the large bowel are familial adenomatous polyposis, responsible for 1% of the annual colorectal cancer burden, and hereditary non-polyposis colorectal cancer that accounts for 2-3% of colorectal cancer cases (9). Both syndromes are remarkable not only by the scientific novelty in hereditary cancer research but only for high practical significance as the knowledge about the peculiar risk of primary and metachronous colorectal cancer as well as about certain extracolonic malignancies is necessary to plan the surgical intervention correctly.