Family history of gastric cancer is associated with the risk of colorectal neoplasia in Korean population

Background: Family history of cancers at different sites except for colorectum has not been evaluated as a risk factor for colorectal neoplasia (CRN).

Aims: To investigate CRN risk according to family history of cancers at 12 different sites, including stomach and colorectum.

Methods: A cross-sectional study was performed on 139,497 asymptomatic Koreans who underwent colonoscopy as part of a health check-up.

Results: The mean age of the study population was 41.6 and the prevalence of CRN was 16.3%. Multivariate analyses revealed that family histories of CRC (adjusted odds ratio; confidence interval, 1.26; 1.17-1.35) and gastric cancer (1.07; 1.01-1.13) were independent risk factors for CRN. Notably, the risk of CRN increased even more for participants with family histories of both CRC and gastric cancer (1.38; 1.12-1.70). Family history of CRC was associated with risk of CRN in participants aged both <50 and ≥50 years, whereas family history of gastric cancer was associated with risk of CRN in participants aged <50 years (1.22; 1.14-1.30), but not in participants aged ≥50 years (1.08; 0.99-1.18).

Conclusions: Family history of gastric cancer was an independent risk factor for CRN, especially in those aged <50years. Persons with family histories of gastric cancer and CRC, especially those with family histories of both, may need to begin colonoscopy earlier.