Evaluation of a population-based approach to familial colorectal cancer.

Abstract

As Newfoundland has the highest rate of familial colorectal cancer (CRC) in the world, we started a population‐based clinic to provide colonoscopic and Lynch syndrome (LS) screening recommendations to families of CRC patients based on family risk. Of 1091 incident patients 51% provided a family history. Seventy‐two percent of families were at low or intermediate–low risk of CRC and colonoscopic screening recommendations were provided by letter. Twenty‐eight percent were at high and intermediate–high risk and were referred to the genetic counsellor, but only 30% (N = 48) were interviewed by study end. Colonoscopy was recommended more frequently than every 5 years in 35% of families. Lower family risk was associated with older age of proband but the frequency of screening colonoscopy recommendations varied across all age groups, driven by variability in family history. Twenty‐four percent had a high MMR predict score for a Lynch syndrome mutation, and 23% fulfilled the Provincial Program criteria for LS screening. A population‐based approach in the provision of colonoscopic screening recommendations to families at risk of CRC was limited by the relatively low response rate. A family history first approach to the identification of LS families was inefficient.