WASHINGTON — Oral antibiotic use among adult patients was not associated with increased risk for early-onset colorectal cancer, according to data presented at Digestive Disease Week.
“The incidence of early-onset colorectal cancer is increasing over the past 3 decades; however, little is known about what may be driving this increase in early-onset CRC,” Jeffrey K. Lee, MD, MPH, a research scientist at Kaiser Permanente Northern California division of research, told Healio. “Greater understanding of the gut microbiome’s role in protecting against gastrointestinal disease development has led to the question of whether antibiotic use — which has increased over the past few decades and is known to perturb the gut microbiome leading to dysregulation of host-microbial interactions — may play a role in promoting early colorectal carcinogenesis.”
Lee noted that although the link is “biologically plausible,” with associations investigated among adults aged older than 50 years with CRC, few studies have examined prior antibiotic use among patients with early-onset CRC. To amend this knowledge gap, Lee and colleagues conducted a population-based, nested case-control study at Kaiser Permanente Northern California.
The researchers identified 1,359 early-onset CRC cases between January 1998 and December 2020 and matched them to 4,711 controls using incidence density sampling and correlated by age, sex, race and ethnicity, primary care facility and duration of drug benefits. Antibiotic exposures, confounders and outcomes were established using electronic databases.
“We found no convincing evidence to establish a link between oral antibiotic use and early-onset colorectal cancer,” Lee told Healio.
According to study results, early-onset CRC cases were commensurate to matched controls based on age (mean age, 44.3 years), sex (47% women), race and ethnicity, primary care facility and length of drug benefits, with no association between antibiotics and early-onset CRC risk in both unadjusted (OR = 1.09; 95% CI, 0.94-1.26) and adjusted (aOR = 1.04; 95% CI, 0.90-1.22) models.
Similarly, the researchers found no notable associations when oral antibiotic use was examined by spectrum of coverage, bacterial target, antibiotic class or sum of antibiotic dispensations.
However, the researchers did note that, when stratified by the number of cumulative days of antibiotic use, an increased risk for early-onset CRC was reported among patients with more than 120 cumulative days of any antibiotic use vs. no antibiotic use (aOR = 1.54; 95% CI, 1.15-2.06).
As this study was not able to examine the effect of antibiotic exposure during childhood and adolescence, Lee recommended that future studies assess the potential influence of early-life antibiotic exposures on early-onset CRC risk.
“Patients should be reassured that antibiotics are safe, at least during early adulthood, and does not increase your risk of early-onset colorectal cancer,” Lee said. “However, antibiotic stewardship is critical to protect patients from harms caused by unnecessary antibiotic use and help combat antibiotic resistance.”
Collapse
Lee JK, et al. Association of oral antibiotics and risk of early-onset colorectal cancer. Presented at: Digestive Disease Week; May 18-21, 2024; Washington (hybrid).
Disclosures:
Lee reports no relevant financial disclosures.
