Prediabetes Associated With Increased Long-Term Colorectal Cancer Risk

Patients with prediabetes may be at increased long-term risk for colorectal cancer (CRC), according to study results presented at the American College of Gastroenterology (ACG) 2022 Annual Meeting, held from October 21 to 26, 2022, in Charlotte, North Carolina, and virtually.

Most patients (>80%) with prediabetes are asymptomatic. As such, prediabetes is underdiagnosed, underreported, and underrepresented in research.

A collaborative group of researchers from the United States searched PubMed/Medline, Embase, Scopus, and Google Scholar for studies of CRC screening among patients with prediabetes through June 2022 to investigate the role of prediabetes in CRC risk. A total of 7 prospective studies and 1 retrospective study were included in this systematic review and meta-analysis.

The pooled cohort comprised 854,876 prediabetes cases and 2,190,511 control cases. The studies were conducted in Japan (n=2), Korea (n=2), China (n=1), Sweden (n=1), the United Kingdom (n=1), and the United States (n=1).

Both the unadjusted (odds ratio [OR], 1.62; 95% CI, 1.35-1.95; I², 85.72%; P <.01) and adjusted (adjusted OR [aOR], 1.16; 95% CI, 1.08-1.25; I², 56.06%; P <.01) analyses found evidence of increased risk for CRC among the cohort with prediabetes compared with controls.

In the sensitivity analysis using a leave-one-out approach, similar findings were observed (estimate, 1.16; 95% CI, 1.08-1.25).

Stratified by study design, the relationship between CRC risk and prediabetes was stronger in the prospective studies (OR, 1.175; 95% CI, 1.065-1.298; P =.001) than the retrospective study (OR, 1.162; 95% CI, 1.033-1.306; P =.012). Stratified by follow-up time, risk for CRC was greatest at 5 to10 years (aOR, 1.257; 95% CI, 1.029-1.534; P =.025) compared with less than 5 years or 10 years or more.

The major limitation of this study is the significant heterogeneity observed in both the univariate and multivariate analyses.

These data indicate that prediabetes may increase long-term risk for CRC. Patients with prediabetes should be counseled about lifestyle modifications to control their prediabetes status such that risk for diabetes and CRC may be mitigated.

“This study further warrants a specific prediabetes screening for patients already at high risk of colorectal cancer with other risk factors,” the study authors wrote.