Study to determine link between insulin glargine and cancer

Type 2 diabetes and obesity are linked to an increased risk of certain cancers. Recently published studies suggested that insulin glargine (a synthetic insulin preparation marketed under the trade name Lantus), may be associated with a higher risk of certain cancers than other insulins or oral glucose lowering medications. However, these studies were unable to control for important factors such as obesity that may have driven the association.

On the other hand, a large randomized trial designed to examine another aspect of diabetes care, which used insulin glargine in one arm, showed no increase in the frequency of cancer with glargine.

To help resolve this important issue, scientists at the University of North Carolina at Chapel Hill are coordinating a large, multi-site retrospective study on insulin users with type 2 diabetes. The study is designed to determine if diabetic patients exposed to insulin glargine have a higher incidence of cancer than diabetic patients exposed to other insulins or to other glucose-lowering medications. Data will be collected from administrative and electronic-medical record databases.

Within this effort, there will be two parallel studies. The principal investigators of the first study are Laurel Habel, Ph.D. and Assiamira Ferrara, M.D., Ph.D. from the Division of Research at Kaiser Permanente Northern California and Daniel Strickland, Ph.D. at the Department of Research and Evaluation at Kaiser Permanente Southern California. Additional sites are being recruited nationwide to conduct a second study to allow for alternative, confirmatory and combined analyses.

The principal investigator of the study, John B. Buse, M.D., Ph.D. , chief of the Division of Endocrinology & Metabolism in the Department of Medicine at UNC, said, "This study is the largest effort to date that examines the hypothetical insulin-cancer relationship. Both its size and the quality of the data will clearly enable us to provide a much better estimate of the safety of glargine in particular and insulin in general with regards to cancer risk."

The study plans to analyze data from about 400,000 people with diabetes, determine their use of diabetes treatments including insulin, and document the incidence of cancer. "We have recruited a truly exceptional group of scientists and resources from across the country to provide as definitive a resolution to the issue as possible over the next year and a half." said Buse.