AACR II: Potential Link Between Dietary Fruit, Fiber and Colorectal Cancer Risk?
Posted: Saturday, June 27, 2020
Ulrike Peters, PhD, MPH, of Fred Hutchinson Cancer Research Center, Seattle, and colleagues assessed the association among fruit and fiber intake and the molecular characteristics of four colorectal cancer subtypes. In a presentation during the 2020 American Association for Cancer Research (AACR) Virtual Annual Meeting II (Abstract 4652/13), they reported that a decreased risk of BRAF-mutated colorectal cancer—but not BRAF wild-type colorectal cancer—may be linked to higher fruit intake. In addition, a decreased risk of several subtypes of colorectal cancer (microsatellite-stable/microsatellite instability [MSI]-low, CpG island methylator phenotype [CIMP]-negative, BRAF-wildtype, and KRAS-wild-type tumors) appeared to be associated with higher fiber intake.
“These results may explain in part the inconsistent findings between fruit or fiber intake and overall colorectal cancer risk that have previously been reported,” noted the investigators.
The study centered on 8,783 colorectal cancer cases with molecular tumor markers for MSI, CIMP, BRAF V600E somatic mutations, and KRAS (codon 12 or 13) somatic mutations and 7,869 controls. Data from these cases were derived from nine observational studies.
According to the study findings, higher fruit intake seemed to be linked to a decreased risk of BRAF-mutated tumors (odds ratio 4th vs. 1st quartile = 0.72). However, this association was not found with BRAF–wild-type tumors (odds ratio 4th vs. 1st quartile = 1.01). In addition, a significant negative association was seen between higher fiber intake and certain molecular subtypes—MSS/MSI-low, CIMP-negative, BRAF–wild-type and KRAS–wild-type), when the investigators used these markers separately and in combination. Although the differences were not statistically significant, this negative association was stronger compared with MSI-high, CIMP-positive, or BRAF- or KRAS-mutated tumors.
Disclosure: The study authors reported no conflicts of interest.