Colorectal cancer (CRC) screening programs have been established worldwide to prevent the development of CRC and to detect it early. CRC screening can be targeted at average- or high-risk... Show moreColorectal cancer (CRC) screening programs have been established worldwide to prevent the development of CRC and to detect it early. CRC screening can be targeted at average- or high-risk individuals. For average-risk individuals, the Dutch fecal immunochemical testing (FIT)-based CRC screening program was introduced in 2014, inviting all individuals aged 55-75 biennially. In Part I of this thesis, outcomes of the CRC screening program in the Netherlands are analyzed (i.e., CRC incidence, mortality, stage distribution, treatment). To optimize the balance between benefits and harms of CRC screening, risk stratification based on fecal hemoglobin concentrations after negative FIT could be the way forward. Part II describes the study protocol of a randomized controlled trail on personalized CRC screening and evaluates the information needs of the target population for personalized CRC screening strategies. For high-risk individuals, intensified CRC screening and surveillance may be needed, given these individuals have higher risk of developing CRC during their lifetime. Testicular cancer survivors treated with platinum-based chemotherapy can be considered high-risk individuals, as they have an increased risk of developing second primary gastrointestinal malignancies. Part III of this thesis explores the carcinogenesis of CRC and the yield of colonoscopy in these individuals. Show less
