Is colonoscopic screening necessary for patients younger than 50 years with gastric adenoma or cancer?

Patients, aged ≥ 50 years, with gastric neoplasm are reported to be at increased risk for colorectal neoplasia (CRN), while data regarding the risk of CRN in young patients, aged < 50 years with gastric neoplasm are limited. We aimed to investigate the risk of CRN according to the presence of gastric neoplasm in patients, aged < 50 years, and conducted a cross-sectional study on 131,888 asymptomatic examinees who underwent both esophagogastroduodenoscopy (EGD) and colonoscopy as part of a health screening program between 2010 and 2014. The prevalence of overall CRN (8.6% vs. 13.2%, P = 0.251) and advanced colorectal neoplasia (ACRN) (0.0% vs. 1.3%, P = 0.345) did not significantly differ according to the presence of gastric neoplasm in subjects, aged < 50 years. However, among subjects aged ≥ 50 years, patients with gastric neoplasm had a significantly higher proportion of overall CRN (48.2% vs. 31.7%, P < 0.001) and ACRN (12.5% vs. 4.5%, P < 0.001) compared with those without gastric neoplasm. Particularly, gastric neoplasm was an independent risk factor for ACRN after controlling for confounding factors among subjects, aged ≥ 50 years. In conclusion, gastric neoplasm was a risk factor for CRN in patients, aged ≥ 50 years, but not in patients, aged < 50 years. Young patients, aged < 50 years with gastric neoplasm do not need to undergo colonoscopy, whereas patients, aged ≥ 50 years with gastric neoplasm, should be considered a higher priority for colonoscopy.