Understanding the role of statin use on advanced prostate cancer outcomes: Does the statin type, cumulative dose, or duration impact survival?

[OBJECTIVE] To further investigate the association of improved survival in men with prostate cancer (PCa) on androgen deprivation therapy (ADT), we hypothesized that increased duration and dose of statin in men with PCa on ADT would show a greater effect.

[METHODS] Using Veterans Affairs databases, we identified all men diagnosed with PCa between 2000 and 2008 that were treated with ADT with follow-up through May 2016. Exclusions included treatment with ADT or statins for ≤6 months or ADT receipt concurrently with localized radiation. Patients were stratified by cumulative duration of statin use <36 or ≥36 months, and we adjusted for cumulative dose and statin type. Cox proportional hazards ratios were calculated for overall survival (OS) and cancer-specific survival (CSS) after propensity score adjustment.

[RESULTS] The cohort after exclusions consisted of 52,763 patients: 32% had a cumulative duration use of statins <36 months. Our analysis for OS showed improved survival in the ≥36 months group (HR 0.60, 95% CI 0.57-0.63), the highest cumulative dose group (HR 0.90, 95% CI 0.82-0.99), and hydrophilic group (HR 0.58, 95% CI 0.54-0.62). In our competing risks analysis for CSS, we noted improved survival in the ≥36 months group (HR 0.83, 95% CI 0.73-0.95) and the highest cumulative dose group (HR 0.74, 95% CI 0.59-0.93), but statin type was not associated with improved survival (HR 0.82, 95% CI 0.66-1.01).

[CONCLUSIONS] We show a strong minimum effective dose/duration type relationship with statin use in Veterans with PCa receiving ADT.