Mayo Clinic logoDiabetes and colon cancer which are both very common in the United States probably target older women. With colorectal cancer remaining the third-leading cause of cancer deaths among women, diabetes has now been apparently recognized as a colon cancer risk factor. Although the mechanisms have not been completely understood, Mayo Clinic physicists seemed to have discovered that older women with diabetes face a more than doubled risk for some types of colorectal cancer.

For the investigation the Mayo study authors analyzed the data of 37,695 participants of the Iowa Women’s Health Study (IWHS). The participants employed in 1986 included women between the age group of 55 to 69 years. Amongst them 2,361 women were diagnosed of Type 2 diabetes and 1,200 had developed colorectal cancer.

The study authors further worked with regional pathology laboratories, to analyze the link between colorectal cancer and diabetes. They then collected the tumor tissue samples from IWHS participants, who were diagnosed with colorectal cancer. The authors linked the tissue samples with other IWHS data. They then examined for cancer pathways and risk factors. They also determined whether those risk factors were associated with the three different molecular markers, microsatellite instability (MSI), CpG island methylation (CIMP), and BRAF gene mutations.

Paul Limburg, M.D. gastroenterologist of Mayo Clinic announced that diabetes was more strongly associated with the MSI-high, CIMP-positive and BRAF-mutation cancer subtypes in the group of older women. He further remarked, that diabetes appeared to confer a greater than twofold increase in risk for these molecularly-defined tumors, compared to women without diabetes.

Anthony Razzak, M.D., a Mayo Clinic study author and presenter at the conference, said, “Knowing that diabetic women have these findings should help to facilitate more appropriate colorectal cancer prevention and treatment options. Our findings may lead to new strategies for colon cancer screening, chemotherapy and chemoprevention in women with diabetes.”

Dr. Razzak clarified that from a study perspective; this information allowed them to clarify how environmental exposures and other risk factors might effect tumor formation at a molecular level. More studies will be undertaken, by the study authors to determine the biology of colorectal cancer and how it is influenced by diabetes. Even investigations about other chronic conditions and exposures will be conducted. This information can then be used for welfare and to improvise patient care.

The findings are being presented at Digestive Disease Week 2010, the annual meeting of the American Gastroenterological Association.