Link between obesity and colorectal cancer established

A new US study has established a link between obesity and an elevated risk of colorectal cancer.

Researchers led by Thomas Jefferson University has revealed the biological connection between the two conditions, in the process also identifying an approved drug that might aid the prevention of cancer.

Examining mice, the investigators found that a high caloric diet turned off expression of a key hormone in the intestine, leading to deactivation of a tumour suppressor pathway. Genetic replacement of that hormone turned the tumour suppressor back on, preventing cancer development even when the mice continued to consume excess calories.

This suggests that the drug linaclotide – which is also known by the brand name Linzess and is structurally related to the lost hormone – could represent a therapeutic approach to preventing colorectal cancer in obese patients.

Senior author Dr Scott Waldman, chair of pharmacology and experimental therapeutics at Thomas Jefferson University's Sidney Kimmel Medical College, said: "Our study suggests that colorectal cancer can be prevented in obese individuals with use of hormone replacement therapy – much as other diseases associated with hormone deficiency, such as loss of insulin in diabetes, can be treated."