By Robert Preidt
"Our findings suggest that women with diabetes may be predisposed to more advanced-stage breast cancer, which may be a contributor to their higher cancer mortality," Dr. Lorraine Lipscombe, a scientist at the Institute for Clinical Evaluative Sciences and Women's College Hospital in Toronto, said in a hospital news release.
She and her colleagues said that breast cancer screening and detection methods may need to be modified for women with diabetes in order to reduce their risk of being diagnosed with advanced cancer.
The researchers analyzed data from more than 38,000 women ages 20 to 105 who were diagnosed with invasive breast cancer between 2007 and 2012. Nearly 16 percent of the women had diabetes.
Women with diabetes were 14 percent more likely to have stage II breast cancer, 21 percent more likely to have stage III breast cancer, and 16 percent more likely to be have stage IV breast cancer, compared to having stage I breast cancer, which is the most treatable stage.
Five-year survival for breast cancer patients with diabetes was 15 percent lower than for those without diabetes, according to the study published March 24 in the journal Breast Cancer Research and Treatment.
The researchers also found that breast cancer patients with diabetes were more likely to have larger tumors and cancer that had spread, compared to those without diabetes.
The study revealed lower mammogram rates in women with diabetes, which could account for later-stage disease, the researchers said.
Researchers only found an association between diabetes and advanced breast cancer in this study, not a cause-and-effect link.