Genes In Large Intestine May Shed Light On Colorectal Cancer: Japan Study

A Japanese research team has uncovered evidence that may explain why colorectal cancer predominantly develops on the left side of the large intestine.

Colorectal cancer is Japan’s most common cancer, with 78% of cases occurring on the left side of the large intestine.

The findings, published in the journal Molecular Cancer and reported by Kyodo News, highlight the differing functions of genes in the left and right sides of the large intestine.

Colorectal cancer is Japan’s most common cancer, with 78% of cases occurring on the left side of the large intestine.

Researchers from Osaka University and other institutions analyzed intestinal tissues from both healthy individuals and colorectal cancer patients in various stages of the disease.

The study found:

• Right Colon: Genes related to xenobiotic stimuli and antimicrobial peptides were highly expressed, suggesting that foreign substances not absorbed in the small intestine undergo further metabolism here.

• Left Colorectum: Genes associated with water retention were prominent, reflecting the region's role in water absorption.

The researchers also emphasized the potential of controlling the terminal ileum—a part of the small intestine crucial for immune response—to help prevent colorectal cancer. Professor Shinichi Yachida of Osaka University hopes these insights will lead to further research into the genetic factors behind the disease's left-sided prevalence.