Extended Insulin Use Is Linked with Colorectal Cancer

A study, reported in Gastroenterology(October 2004), indicated that individualswith type 2 diabetes who needlong-term insulin therapy may bemore susceptible to colorectal cancer.The study involved 24,918 patientswith type 2 diabetes from a UnitedKingdom database. The analysis includedindividuals with at least 3 yearsof follow-up data after their initialdiagnosis. The participants who werediagnosed with colorectal cancer withinthe first year of insulin therapywere excluded.

The research showed that thelonger patients received insulin thehigher the risk of colorectal cancer.Individuals who received at least 3years of insulin therapy had 3 timesthe risk of developing that cancer,compared with patients who receivedno insulin. The risk of individuals on>5 years of insulin therapy was 4times higher, compared with the noninsulingroup.

Gene Barrett, MD, professor of medicineat the University of Virginia, saidthat the study offered no conclusiveevidence of an association betweeninsulin dependence and colorectalcancer.