Outcomes of screening and surveillance in people with two parents affected by colorectal cancers: experiences from the Familial Bowel Cancer Service

BACKGROUND: The Familial Bowel Cancer Service at The Royal Melbourne Hospital was started in 1980 in order to offer bowel cancer screening services to those felt to be at a higher risk of CRC due to their family history, and upon registration in this service, patients gave consent for recording of their individual and familial medical history as pertaining to colorectal cancer in the FamBIS database. Using the FamBIS database, we sought to understand whether the subpopulation of individuals in whom both parents were diagnosed with colorectal cancer carried a higher risk of colorectal cancer or neoplastic polyps and should therefore undergo more intensive screening above that of the average-risk individual. METHODS: We conducted a single-centre retrospective cohort-study of adults (18 years of age and older) in the FamBIS database, with review of their medical histories as pertaining to CRC diagnosis, screening, and surveillance from 1980 to 2015. RESULTS: We identified and reviewed the medical histories of 96 registrants from 62 unique families. Registrants began screening as early as 24 years of age, with the mean age of first screening being at 44.6 ± 10.7 years old. The mean duration of screening was 17.3 ± 10.1 years, and through their screening period, registrants underwent an average of 11.5 ± 9.1 FOBTs and 4.4 ± 3.1 colonoscopies or sigmoidoscopies. Over the course of screening, 41 (42.7%) registrants were found to have at least one neoplasm of any kind (including adenomas, advanced adenomas, and CRC) as their first positive colonoscopic finding. In total, 12 (12.5%) of the registrants were found to have an advanced neoplasm over the course of screening and surveillance, while only 2 patients were found to be diagnosed with CRC. CONCLUSIONS: The prevalence rates for neoplasms, advanced neoplasms, and CRC in our current study were statistically significantly higher compared with those seen in average-risk populations. This supports the importance of more intensive screening for this subpopulation in preventing colorectal cancers, as well as pre-and early-cancerous neoplasms.