(Ivanhoe Newswire) -- Older women with diabetes face more than double
the risk for some types of colorectal cancer.
Colorectal cancer is the third leading cause of cancer deaths among women in
the United States. Diabetes has been identified as a colon cancer risk
factor, but the mechanisms are not completely understood. Researchers
examined data from 37,695 participants of the Iowa Women's Health Study (IWHS),
which enrolled women over age 55 in 1986 and remains ongoing. Of these
women, 2,361 reported a diagnosis of type 2 diabetes and 1,200 developed
colorectal cancer.
The researchers obtained tumor tissue samples from IWHS participants who
were diagnosed with colorectal cancer. They linked the tissue samples with
other IWHS data, looking for cancer pathways and risk factors, and whether
those risk factors were associated with three different molecular markers:
microsatellite instability (MSI), CpG island methylation (CIMP), and BRAF
gene mutations.
"Diabetes was more strongly associated with the MSI-high, CIMP-positive and
BRAF-mutation cancer subtypes in this group of older women," Mayo Clinic
gastroenterologist Paul Limburg, M.D., was quoted as saying. Dr. Limburg
explained that diabetes appeared to confer a greater than twofold increase
in risk for these molecularly defined tumors.
"Knowing that diabetic women have these findings should help to facilitate
more appropriate colorectal cancer prevention and treatment options," study
presenter Anthony Razzak, M.D., a Mayo Clinic research fellow, was quoted as
saying. "Our findings may lead to new strategies for colon cancer screening,
chemotherapy and chemoprevention in women with diabetes."
SOURCE: Presented at the annual meeting of the American
Gastroenterological Association, New Orleans, May 2, 2010
