Free-fatty acid receptor-4 gene polymorphism (rs61866610) and colorectal cancer risk

Abstract

This study aimed to investigate the impact of Free-fatty acid receptor-4 (FFAR4) rs61866610 polymorphism on colorectal cancer (CRC) risk. Herein, ninety-two histopathologically confirmed CRC patients and 95 healthy individuals were evaluated for FFAR4 polymorphism by RFLP-PCR. Gender, age, body mass index (BMI), underlying disease, and smoking status were recorded for all subjects. Clinical and histopathologic findings including tumor grade and TNM stage were also prepared in the patient group. Except for type 2 diabetes which was more prevalent in the control group, there were no differences between the two groups regarding underlying diseases (p > 0.05). The frequency of genotypes was as follows: in the CRC group 75% wild type, 23.9% heterozygous, and 1.1% homozygous mutant. In the control group 85.3% wild type, 12.6% heterozygous, and 2.1% homozygous mutant. Mutant allele carriers were more frequent in CRC subjects (25%) than in the normal group (14.7%) but it did not reach a significant level. The frequency of mutant genotypes in colon cancer and rectal cancer was 27.5% and 8.3% respectively (p = 0.282). The mutant genotypes were found more in patients with high-grade tumors (p = 0.154). Subjects with stage III/IV had a higher frequency of mutant genotypes than low-stage cases (p = 0.011). No association was found regarding rs61866610 and obesity or type 2 diabetes (p > 0.05). In conclusion, FFAR4 (rs61866610) has no significant association with the risk of CRC, but the higher frequency of mutant genotypes in subjects with advanced cancer stages (III/IV) suggests further studies to determine the role of FFAR4 in colorectal tumorigenesis.