Early-Age Onset Colorectal Neoplasia in Average-Risk Individuals Undergoing Screening Colonoscopy: A Systematic Review and Meta-Analysis

Abstract

Background/Aims Incidence and mortality associated with early age onset colorectal cancer (EAO-CRC) is increasing, prompting professional society recommendations to lower the screening age in average risk individuals. The yield of screening individuals <50 years old is not known. Methods A systematic review of 3 databases from inception through July 2020 was performed in all languages that reported colonoscopy findings in average risk individuals<50 years old. The primary outcomes were EAO colorectal neoplasia (EAO-CRN) and advanced colorectal neoplasia (EAO-aCRN) prevalence. Subgroup analyses were performed based on sex, geographic location, time period, and age including comparison to age 50-59. Generalized linear mixed model with random intercept logistic regression and fixed subgroup effects were performed Results Of 10,123 unique articles, 17 studies published between 2002-2020, including 51,811 average-risk individuals from four continents, were included. The pooled rate of EAO-CRN was 13.7% (95%CI: 0.112-0.168) and EAO-aCRN was 2.2% (95%CI: 0.016-0.031). Prevalence of CRC was .05% (0.00029-0.0008). Rates of EAO-CRN were higher in men compared to women (RR 1.71, 1.49–1.98), and highest in the United States (15.6%:12.2-19.7) compared to Europe (14.9%:6.9-29.3), East Asia (13.4%:10.3-17.2), and the Middle East (9.8%:7.8-12.2)(p=0.04) The rate of EAO-CRN in age 45-49 and 50-59 was 17.8% (14.5-21.6) and 24.8% (19.5-30.8), respectively (p=0.04). The rate of EAO-aCRN in age 45-49 was 3.6% (1.9-6.7) and 4.2% (3.2-5.7), respectively (p=0.69) Conclusions The rate of advanced colorecta neoplasia in individuals age 45-49 was similar to the rate observed in age 50-59, suggesting that expanding screening to this population could yield similar impact on colorectal cancer risk reduction.