Is There an Association Between Antidiabetic Medication and Prostate Cancer?
Posted: Monday, December 2, 2019
The inverse association between diabetes and prostate cancer is not mediated via antidiabetic medications lowering prostate-specific antigen (PSA) levels, thereby masking prostate cancer, according to a study published in JAMA Network Open. Kerri Beckmann, PhD, of King’s College, London, and colleagues explained there may be potential detection bias among the population of men with diabetes due to fewer biopsies among those taking antidiabetic medications.
The population-based cohort study used data from the Stockholm PSA and Biopsy Register. The patients, all free of prostate cancer, were between the ages of 40 and 79 and resided in Stockholm County, Sweden, from January 2006 to December 2015. There were a total of 564,666 men in this cohort; 4,583 were exposed to metformin, 1,104 were exposed to sulfonylurea, and 978 were exposed to insulin. All men on an antidiabetic medication were age-matched with unexposed men in a 1:5 ratio.
Men who were exposed to some type of antidiabetic medication had lower median PSA levels before starting treatment than unexposed men (1.2 vs. 1.6 ng/mL). However, PSA levels did not vary between the exposed and unexposed groups after treatment with the medications. The frequency of PSA testing was higher in men who received metformin (rate ratio = 1.07) and sulfonylurea (rate ratio = 1.06), but it was lower in those receiving insulin (rate ratio = 0.79). Notably, the likelihood of biopsy after an elevated PSA level was lower among men on metformin treatment (odds ratio = 0.87) and insulin (odds ratio = 0.83). There appeared to be no difference in the detection of prostate cancer at biopsy, regardless of the PSA levels that triggered the biopsy.
Disclosure: The full disclosures of the study authors can be found at jamanetwork.com.