Of all colorectal cancer (CRC) cases, 15-20% is related to familial or hereditary factors. Diagnosing familial and hereditary CRC syndromes is important for several reasons. One of these is that surveillance colonoscopies can reduce CRC incidence and mortality importantly. A complete family history collection combined with an adequate application of referral criteria for genetic counseling and surveillance colonoscopies can help to identify persons at risk of these syndromes. However, in daily practice many physicians do not adequately explore family history. As a consequence, only 15-30% of CRC patients and their relatives who would qualify for referral are appropriately referred for preventive measures. These delays in detecting and managing cancer can lead to unnecessary morbidity and mortality. The studies in the first part of this thesis investigated methods to improve the identification of patients with familial and hereditary CRC syndromes.The second part of this thesis focuses on polyposis syndromes, a subgroup of familial and hereditary CRC syndromes, characterized by the presence of multiple colorectal polyps . The risk of CRC in polyposis syndromes is well described and, consequently, clear screening and surveillance recommendations for CRC exist. However, of concern are manifestations outside the colon. The risks of these extra-colonic manifestations are increased but less well reported. More knowledge is needed to determine if, how, and when screening and surveillance of extra-colonic manifestations in those syndromes is indicated. The studies in the second part of this thesis aimed to increase the knowledge on extra-colonic manifestations in patients with polyposis syndromes.
|Award date||8 Sep 2017|
|Publication status||Published - 2017|