Study Examines Link Between Breast Cancer and Diabetes

Chemo seems to play a role in early diagnosis of diabetes in postmenopausal patients

THURSDAY, Dec. 13 (HealthDay News) -- Postmenopausal breast cancer survivors are at increased risk for developing diabetes and should be screened for the disease more closely, a new study suggests.

Researchers analyzed data from 1996 to 2008 from the province of Ontario, Canada, to determine the incidence of diabetes among nearly 25,000 breast cancer survivors aged 55 or older and nearly 125,000 age-matched women without breast cancer.

During a median follow-up of more than five years, nearly 10 percent of all the women in the study developed diabetes. Compared to those who had not had breast cancer, the risk of diabetes among breast cancer survivors was 7 percent higher two years after cancer diagnosis and 21 percent higher 10 years after cancer diagnosis, the investigators found.

The risk of diabetes, however, decreased over time among breast cancer survivors who had undergone chemotherapy. Their risk compared to women without breast cancer was 24 percent higher in the first two years after cancer diagnosis and 8 percent higher 10 years after cancer diagnosis, according to the study, which was published Dec. 12 in the journal Diabetologia.

"It is possible that chemotherapy treatment may bring out diabetes earlier in susceptible women," study author Dr. Lorraine Lipscombe, of Women's College Hospital and Women's College Research Institute in Toronto, said in a journal news release. "Increased weight gain has been noted [after receiving] chemotherapy for breast cancer, which may be a factor in the increased risk of diabetes in women receiving treatment."