Additionally, two studies in Sweden and Scotland suggested that women using insulin glargine alone had a significantly higher risk of breast cancer as compared with users of other types of insulin, whereas this increased risk was not observed among those who received insulin glargine in combination with other insulin . In contrast, a UK study found that despite a higher risk of overall cancer among diabetic patients receiving insulin or sulfonylurea compared to those using metformin, the risk was similar for different insulin formulations at the doses used in clinical AB1010 VEGFR/PDGFR inhibitor practice . Residual confounding, reverse causation, selection or detection biases might have influenced the validity of these studies . In this study, we examined whether cancer incidence was associated with the use of insulin glargine compared to intermediate/long-acting human insulin using the Taiwan National Health Insurance claims database. A total of 10,190 insulin glargine initiators and 49,253 intermediate/long-acting HI initiators were included in the analysis . These two treatment groups differed in many baseline characteristics . As compared with intermediate/ long-acting HI initiators, those who starting insulin glargine therapy were more likely to have history of ketoacidosis or nonketotic hyperosmolarity and retinopathy, but less likely to have cerebrovascular and peripheral vascular Fulvestrant Estrogen Receptor inhibitor diseases, nephropathy, chronic kidney and lung disease; were mostly cared for by endocrinologists and in the medical centers. A significantly higher proportion of insulin glargine initiators also received oral antidiabetic agents and statins, while less received fast-acting insulin therapy during the 6-month period prior to the initiation of insulin glargine. Insulin glargine initiators received more frequent hemoglobin A1C measurements and have more frequent outpatient visits due to diabetes but less likely to be hospitalized due to either diabetes or non-diabetes problems. In a Chinese population with high incidence of colorectal, liver, and lung cancers, insulin glargine was not associated with an excess risk of overall cancer as compared to intermediate/longacting HI among adult type 2 diabetes patients over an average follow-up of 2 years. This result is consistent with the finding from a randomized controlled trial enrolling 1,017 type 2 diabetes patients comparing insulin glargine with neutral protamine Hagedorn insulin .