PHILADELPHIA — according to the results of a retrospective study.
“This is the first large study to investigate the impact of GLP-1 RA use on EO-CRC risk,” principal investigator Temitope Olasehinde, MD, resident physician at the University Hospitals Cleveland Medical Center, Case Western Reserve University in Cleveland, Ohio, said in an interview.
The results indicate the GLP-1 RAs have a potentially protective role to play in combating EO-CRC, the incidence of which is notably rising in younger adults, with a corresponding increase in associated mortality.
Previous studies investigating the link between GLP-1 RAs and CRC did not capture patients aged younger than 50 years; thus, it was unknown if these results could be extrapolated to a younger age group, said Olasehinde.
The researcher presented the findings at the annual meeting of the American College of Gastroenterology.
Retrospective Database Analysis
Olasehinde and colleagues analyzed data from TriNetX, a large federated deidentified health research network, to identify patients (age ≤ 49 years) with diagnosed T2D subsequently prescribed antidiabetic medications who had not received a prior diagnosis of CRC. Additionally, patients were stratified on the basis of first-time GLP-1 RA use.
They identified 2,025,034 drug-naive patients with T2D; of these, 284,685 were subsequently prescribed GLP-1 RAs, and 1,740,349 remained in the non–GLP-1 RA cohort. Following propensity score matching, there were 86,186 patients in each cohort.
Patients who received GLP-1 RAs had significantly lower odds of developing EO-CRC than those who received non–GLP-1 RAs (0.6% vs 0.9%; P < .001; odds ratio [OR], 0.61; 95% CI, 0.54-068).
Furthermore, a sub-analysis revealed that patients who were obese and taking GLP-1 RAs had significantly lower odds of developing EO-CRC than patients who were obese but not taking GLP-1 RAs (0.7% vs 1.1%; P < .001; OR, 0.58; 95% CI, 0.50-067).
A Proposed Protective Effect
Although GLP-1 RAs are indicated for the treatment of T2D and obesity, recent evidence suggests that they may play a role in reducing the risk for CRC as well. This protective effect may be produced not only by addressing T2D and obesity — both important risk factors for CRC — but also via cellular mechanisms, Olasehinde noted.
“GLP-1 receptors are widely expressed throughout the gastrointestinal tract, with various effects on tissues in the stomach, small intestine, and colon,” she explained. Specifically, activation of these receptors in the proximal and distal colon promotes the release of “important factors that protect and facilitate healing of the intestinal epithelium” and “regulate the gut microbiome.”
This is particularly relevant in EO-CRC, she added, given its greater association with T2D and obesity, both factors that “have been shown to create dysbiosis in the gut microbiome and low-grade inflammation via release of free radicals/inflammatory cytokines.”
These results provide more evidence that EO-CRC “is clinically and molecularly distinct from late-onset colorectal cancer,” which is important for both clinicians and patients to understand, said Olasehinde.
“It is imperative that we are all aware of the specific signs and symptoms this population presents with and the implications of this diagnosis in younger age groups,” she added. “Patients should continue making informed dietary and lifestyle modifications/choices to help reduce the burden of EO-CRC.”
Hypothesis-Generating Results
Aasma Shaukat, MD, MPH, who was not affiliated with the research, called the results promising but — at this stage — primarily useful for stimulating future research.
"We do need more studies such as this to generate hypotheses that can be studied prospectively," Shaukat, professor of medicine and population health, and director of GI Outcomes Research at NYU Langone Health in New York City, told Medscape Medical News.
She referred to another study, published in JAMA Oncology, that also used the TriNetX research network, which showed that GLP-1 RAs were associated with reduced CRC risk in drug-naive patients with T2D.
Shaukat also noted that the current analysis has limitations that should be considered. "The study is retrospective, and confounding is a possibility,” she said.
“How the groups that did and did not receive GLP-1 RAs differ in other risk factors that could be the drivers of the cancers is not known. Whether cancers were detected through screening or symptoms, stage, and other features that may differ are not known. Finally, since we don’t know who did or did not have colonoscopy, undiagnosed cancers are not known," she explained.
Shaukat, who was the lead author of the ACG 2021 Colorectal Cancer Screening Guidelines, added that the field would benefit from studies providing "biological plausibility information, such as animal studies to understand how GLP-1 RAs may modulate risk of colon cancer; other population-based cohort studies on the incidence of colon cancer among GLP-1 RA users and non-users; and prospective trials on chemoprevention."
The study had no specific funding. Olasehinde reported no relevant financial relationships. Shaukat reported serving as a consultant for Freenome, Medtronic, and Motus GI, as well as an advisory board member for Iterative Scopes Inc.
A version of this article appeared on Medscape.com.
