Objectives: Compared with the general population, first-degree relatives (FDRs) of colorectal cancer (CRC) patients have a two-fold to four-fold higher risk of developing CRC. Little data is available regarding communication between doctors and CRC patients about risk to FDRs. We aimed to evaluate CRC patients' knowledge of FDRs' increased CRC risk, and FDRs' knowledge of this risk and adherence to CRC screening.
Materials and methods: In this retrospective, single-center, population-based observational study, patients aged 18-80 years who underwent surgery for CRC between January 2005 and May 2010 were asked to complete a questionnaire. A questionnaire sent to the patients' FDRs (siblings and children) asked whether they had been advised to undergo any CRC screening examination, whether they had done so, and if so, when initiated and by whom. Main outcome measurements were: CRC patients' and their FDRs' information status regarding the FDRs' increased CRC risk and screening status.
Results: Of 343 index patients (390 contacted, 47 deceased/moved), 134 replied to the survey (39.1% response rate). Among index patients, 82.1% (110/134) were informed about FDRs' increased CRC risk. This information was provided mainly by gastroenterologists and general practitioners (65.7 and 28.4%, respectively). Among FDRs, 85.1% (143/168) were informed about their increased CRC risk, but 69% did not undergo a screening colonoscopy. Among the FDRs more than 50 years of age, 40.8% did not undergo a screening colonoscopy.
Conclusion: In Switzerland, CRC patients and their FDRs are well informed about FDRs' increased CRC risk. However, the majority of FDRs do not undergo the recommended CRC screening.