Prolactin-increasing antipsychotics use and reduced risk of prostate cancer: a population-wide cohort and nested case-control study

ObjectiveThis study aims to investigate whether users of prolactin-increasing antipsychotics exhibit a lower risk of prostate cancer compared to those using prolactin-sparing antipsychotics. MethodsUsing territory-wide electronic health records from Hong Kong, we conducted a retrospective cohort study along with a nested case-control analyses involving adults who were prescribed antipsychotics and had no history of cancer, organ transplantation, or sexually transmitted infections. Baseline characteristics included demographics, comorbidities, and co-medications. The outcome of interest was incident prostate cancer. Poisson regression, incorporating inverse probability of treatment weighting (IPTW) and multivariable adjustment, were used to estimate incidence rate ratios (IRR) in the cohort analyses. A conditional logistic regression model was applied in the nested case-control analyses to calculate odds ratios (OR) associated with longer-term use of prolactin-increasing antipsychotics, compared to short-term use or non-use. ResultsThe cohort study included 81,177 individuals in the primary analyses. Users of prolactin-increasing antipsychotics showed a halved risk of prostate cancer compared to the prolactin-sparing group, with an adjusted IRR (aIRR) of 0.410 (95% CI: 0.237-0.710). In the nested case-control analyses, 291 cases were identified. A similarly reduced risk was observed among those who had used prolactin-increasing antipsychotics for 1-5 years, with an adjusted OR (aOR) of 0.569 (95% CI: 0.356-0.909). This association is more pronounced in people under the age of 75 but not among those aged above. ConclusionProlactin-increasing antipsychotics were associated with a markedly lower risk of prostate cancer. If the findings are further substantiated, this potential benefit from prolactin-increasing antipsychotics should be considered.