Frequency of a positive family history of colorectal cancer in general practice: a cross-sectional study.

Abstract

Evidence on the frequency of a positive family history of colorectal cancer (CRC) among individuals aged <55 years is lacking. General practice setting might be well suited for the identification of individuals in this above-average risk group. To determine the frequency of a reported positive family history of CRC among patients aged 40 to 54 years in a general practice setting. We conducted a cross-sectional study in 21 general practices in Germany. Patients aged 40 to 54 years were identified by means of the practice software and interviewed by health care assistants using a standardized four-item questionnaire. Outcome was occurrence of a positive family history of CRC, defined as at least one first-degree relative (FDR: parents, siblings, or children) with CRC. Further measurements were FDRs with CRC / colorectal polyps (adenomas) diagnosed before the age of 50 and occurrence of three or more relatives with colorectal, stomach, cervical, ovarian, urethel or renal pelvic cancer. Out of 6723 participants, 7.2% (95% confidence interval [CI] 6.6% to 7.8%) reported at least one FDR with CRC and 1.2% (95% CI 0.9% to 1.5%) reported FDRs with CRC diagnosed before the age of 50. A further 2.6% (95% CI 2.3% to 3.0%) reported colorectal polyps in FDRs diagnosed before the age of 50 and 2.1% (95% CI 1.8% to 2.5%) reported three or more relatives with entities mentioned above. One in 14 patients reported at least one FDR with CRC. General practice should be considered when defining requirements of risk-adapted CRC screening.