Researchers at Roswell Park Cancer Institute (RPCI) and the University at Buffalo (UB) found that post-menopausal women using metformin for diabetes may be at lower risk for developing certain cancers and dying from these diseases.
The study, based on data from the Women’s Health Initiative (WHI), also shows that women with diabetes were more likely to develop cancer, while the risk is lower in women without diabetes. The study’s findings were published in the International Journal of Cancer.
The research team, including Zhihong Gong, assistant professor of Oncology in the Department of Cancer Prevention and Control at Roswell Park and Jean Wactawski-Wende from Dean of the School of Public Health and Health Professions at the University at Buffalo, examined information from 145,826 post-menopausal women aged between 50 and 79 years. This data was collected by 40 U.S. clinical centers, who participated in the WHI between 1993 and 1998.
According to their findings, women with diabetes had a 45% greater risk of death from invasive cancer overall versus women without diabetes. The risk of cancer death differed significantly between metformin users and nonusers, among women with diabetes.
Women with diabetes had a 13% higher risk of developing invasive cancer, compared to women without diabetes. These women also face increased risk that ranges from 20% to nearly double the chances of being diagnosed with the following cancers: colon, liver, pancreas, endometrial and non-Hodgkin lymphoma, according to the study.
Additionally, researchers found that metformin use was associated with better survival in diabetes patients diagnosed with ovarian, colorectal and breast cancer.
“Our findings suggest that diabetes remains a risk factor for cancer overall and increases the risk of certain cancers. But we also found a lower cancer risk for certain cancers among those patients who have used metformin for many years,” Dr. Gong said.
Further studies are required to clarify the long-term impact of metformin on cancer risk and survival, according to researchers.