Similar Breast Cancer Risk in Women Older Than 65 Years Initiating Glargine, Detemir, and NPH Insulins

Retrospective new-user cohort study of female Medicare beneficiaries aged ≥65 yrs initiating glargine (n=203,159),detemir (n=67,012),or neutral protamine Hagedorn [NPH] (n=47,388), found ever use of glargine not linked to increased risk of breast cancer vs neutral NPH or detemir.

SPS commentary:

Long-acting insulin analogs, glargine and detemir are structurally altered human insulins designed to overcome the limitations of neutral protamine Hagedorn (NPH) insulin, namely, its short half-life and risk of nocturnal hypoglycaemia. However, altering human insulin may influence mitogenicity, and concern has been raised about the carcinogenic potential of glargine Given the inconsistent findings and small numbers of long-term glargine and detemir users in previous observational studies, uncertainty remains as to whether longer-term glargine use influences breast cancer risk. This current study did not find an increased risk compared with NPH or detemir use, irrespective of dose, duration of use, or length of follow-up.


In 2013, the European Medicines Agency completed a review of new data on the cancer risk with insulin glargine-containing medicines and had concluded that the data do not show an increased risk of cancer and that the balance of the medicine’s benefits and risks remains unchanged.


Diabetes Care

Resource links:

European Medicines Agency’s review