INS and breast cancer: As for the association of insulin therapy with breast cancer, the UK's General Practice Research Database included a cohort of 15,227 women with type 2 diabetes, treated with insulin glargine (4,579 users) and matched with users of other insulins (10,648 users), and followed up till the first breast cancer diagnosis or until the end of December 2009, of which 246 developed breast cancer during the 8-year followup.