Insulin glargine and cancer risk: an opinion statement of the Endocrine and Metabolism Practice and Research Network of the American College of Clinical Pharmacy.

Diabetes mellitus has reached epidemic proportions worldwide, eliciting extensive research on both the disease process and its treatment. Regardless of diabetes type, the progressive nature of the disease makes insulin the long-term mainstay of diabetes management. Recently, the insulin analog glargine was reported in several epidemiologic studies to be associated with an increased risk of cancer. Inconsistent study results and media attention have caused much angst and concern to health care professionals and the general population. A clear understanding of the current evidence is needed to adequately develop a patient-oriented risk:benefit assessment. Members of the Endocrine and Metabolism Practice and Research Network of the American College of Clinical Pharmacy evaluated available evidence to provide guidance and discussion on the risk of cancer with insulin glargine use. We believe the current link between insulin glargine and cancer is tenuous but merits further evaluation. An independent analysis of all available glargine clinical trial data should be performed, and a vigorous postmarketing safety study of glargine should be conducted. Until more substantial data are available, however, neither the choice of initial insulin therapy nor insulin maintenance regimens should be influenced by the current information linking insulin glargine to cancer.