More breast cancer diagnosed in women with diabetes
NEW YORK (Reuters Health) - Women with newly diagnosed diabetes may be more likely to get also a diagnosis of breast cancer than those without diabetes, suggests a new study from Canada.
It is not the first time that diabetes has been linked to new cases of breast cancer or other cancers. But the results also suggest that at least part of the reason why most doctors find breast cancer in diabetics because they are looking for more difficult - and not necessarily because diabetes itself increases the risk of a woman cancer.
"The relationship that we (including diabetes and cancer), we wondered if there was anything in the fact that people with diabetes go to the doctor's office more often," said Jeffrey Johnson, University of Alberta in Edmonton , who worked on the study.
"When a new diagnosis of diabetes is made, people spend a lot of tests and general health." Which may include the selection of breast cancer with mammograms, he added.
Previous studies found that people with diabetes have an increased risk of colorectal cancer of the liver, and pancreas, and breast cancer.
Next, the researchers suggest that certain behaviors can increase the risk of both types of diseases, such as smoking, physical inactivity and not eating well, and that those that explain the relationship.
It is also possible that changes in insulin and sugar levels in the blood that come with diabetes easier for breast tumors grow, Johnson said.
While the explanations might be partly behind the increase in breast cancer researchers have found, additional doctor visits and tests "certainly seems to contribute to some extent."
Johnson and his colleagues consulted a database with about 170,000 women in British Columbia - half with newly diagnosed type 2 diabetes and half without diabetes - and the follow-up for the next four to five years. During that time, about 2,400 women, or 1.4 percent, were diagnosed with breast cancer.
Women in both groups had a similar chance of breast cancer. However, when the researchers broke down the age and focused on the time, shortly after the diagnosis of diabetes, found that older, postmenopausal women with diabetes were slightly more likely to be diagnosed with breast cancer that women without diabetes.
Among those over 55 years, women with diagnosed diabetes in the last three months were 30 percent more likely to also obtain a diagnosis of breast cancer than those without diabetes. But even in these women, the researchers could not say with certainty that the finding was not due to chance, according to findings published in the journal Diabetes Care.
After a few months - when the pace of appointments and tests after a diagnosis of diabetes has been reduced - there was no difference in frequency of breast cancer diagnosed in women with and without diabetes.
Johnson said the finding does not rule out other explanations, such as common risk factors for diabetes and cancer or an increase in the hormone-driven tumor growth.
"I think there are so many things happening in the relationship that this is perhaps part of it," he told Reuters Health. "We're very early in the understanding of this relationship."
Dr. Christos Mantzoros, a hormone expert at Harvard Medical School in Boston, said the new findings could mean that the highest rate of breast cancer diagnosis was due to increased monitoring and detection in diabetic patients, or that the roots common diseases can lead both to develop in a short period of time.
"Women with diabetes need to be more vigilant and their doctors should have in them the detection of malignant tumors associated with diabetes, including but not limited to, breast cancer," said Mantzoros, who was not involved in the new study, Reuters Health in an email.
Johnson said the main message to women is still cutting behaviors such as smoking that increase the risk of disease and be screened for breast cancer as recommended.
The U.S. Preventive Services Task Force, a group of experts funded by the government, calls for a mammogram every two years for women between 50 and 74.
More breast cancer diagnosed in women with diabetes
