QUEBEC CITY — One-third of menopausal women with diabetes do not receive annual screening mammography, according to results of a large study.
“Even though they had more frequent visits to physicians, compared with healthy women, women with diabetes have a 32% lower likelihood of getting mammograms,” said Lorraine Lipscombe, M.D., a research fellow at the Institute for Clinical Evaluative Sciences, Toronto.
The retrospective study included approximately 69,000 women with diabetes, aged between 50 and 69 years, and compared them with about 663,000 controls of the same age, she reported at the joint annual meeting of the Canadian Diabetes Association and the Canadian Society of Endocrinology and Metabolism.
The women's medical records were taken from a provincial database as well as the Ontario Diabetes Database and tracked for 2 years, starting from their first physician visit to determine whether they had a screening mammogram, said Dr. Lipscombe, also of Sunnybrook and Women's College Health Sciences Centre, Toronto.
Compared with healthy women, those with diabetes had more physician visits per year (nine versus seven) and were more likely to see a specialist (29% versus 11%). However, significantly fewer diabetic women had at least one screening mammogram during the study period (38% vs. 47%, odds ratio 0.68).
This finding is of particular concern in light of evidence that suggests there may be an increased risk of breast cancer in women with diabetes, Dr. Lipscombe told this newspaper.
The mechanism for this increased risk may be a higher rate of obesity in this population, which can predispose women to breast cancer. It may also be related to insulin exposure, she said.
“Not just treatment with insulin, but possibly also the fact that there is a state of insulin resistance for many years before the onset of diabetes. This means that the body makes more insulin than normal, and because insulin is a growth factor it can increase the risk of breast cancer,” she said.
The study results suggest that primary preventive care may be suboptimal in diabetes patients, and physicians should consider ways to ensure that patients get regular mammography reminders, according to Dr. Lipscombe.