Prolactin-Elevating Antipsychotics and the Risk of Endometrial Cancer

Background: The use of antipsychotics may increase the risk of endometrial cancer through elevation of prolactin levels. We investigated the association between antipsychotics that are known to cause prolactin elevation and the risk of endometrial cancer.

Methods: In data from the United Kingdom Clinical Practice Research Datalink, all women who were newly treated with antipsychotics from 1990-2013 were identified and followed until 2014. Within this cohort of antipsychotic users, a nested case-control analysis was conducted. Main exposure was nonsporadic use of prolactin-elevating antipsychotics, and the active comparator was prolactin-sparing antipsychotics. Cases were women newly diagnosed with endometrial cancer (ICD-10) matched with up to 20 controls on age, calendar year of cohort entry, linkability to the Hospital Episode Statistics repository, and duration of follow-up. Conditional logistic regression models were used to determine the association of prolactin-elevating antipsychotics and endometrial cancer compared with prolactin-sparing antipsychotics. All analyses were adjusted for relevant potential confounders, including smoking, obesity, and diabetes mellitus.

Results: The cohort included 65,930 women. During 366,112 person-years of follow-up, there were 139 cases of endometrial cancer (incidence rate: 38/100,000 person-years), which were matched to 1,603 controls. Compared with the use of prolactin-sparing antipsychotics, the use of prolactin-elevating antipsychotics was not associated with an increased risk of endometrial cancer (adjusted odds ratio [aOR] = 1.00; 95% CI, 0.68-1.48). These findings remained similar with different durations of use (≤ 1 year, aOR = 1.07; 95% CI, 0.64-1.78, and > 1 year, aOR = 0.95; 95% CI, 0.58-1.54) and were robust to various sensitivity analyses.

Conclusions: Prolactin-elevating antipsychotics were not associated with an increased risk of endometrial cancer.