A study published in 2009 suggested that people who took higher doses of glargine insulin had an increased risk of cancers of all forms. Other studies have not confirmed this association.
Two recent studies, the Northern European Database Study and the Kaiser Permanente California Cohort Study have found no increased risk. The Northern European Study compared the risk of breast cancer in women, prostate cancer in men and colorectal cancer in both sexes who were given glargine insulin or human insulin. 17,800 cancers were diagnosed in these insulin users, but there was no difference in the frequency of these cancers between those who took glargine and those who took human insulin.
In the Kaiser Permanente Study, people who switched to glargine insulin from NPH insulin were compared as well as new insulin users who were started on NPH or glargine. There was no difference in the occurrence of cancer in these groups.
Use of glargine insulin does not appear to be associated with more cancer.
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