Influence of Statins on Survival Outcome in Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Androgen Receptor Inhibitors

Are statins onco- suppressive agents for every type of tumor? A systematic review of literature

INTRODUCTION

Statins, in the role of anti-cancer agents, have been used in many types of cancers with results in some cases promising while, in others, disappointing.

AREAS COVERED

The purpose of this review is to identify and highlight data from literature on the successes or failure of using statins as anti-cancer agents. We asked ourselves the following two questions:1. Could statins, which are taken mostly to reduce cardiovascular risk, guarantee a lower incidence or a better cancer disease prognosis, concerning local recurrence, metastasis or mortality?2. Does statins intake (before and/or after cancer diagnosis) improve the prognosis or increase the chemotherapeutic action when combined with other anticancer therapies? For the first question twenty-seven manuscripts have been selected, for the second one, twenty-eight.

EXPERT OPINION

There are data which correlate statins with a possible tumor suppressive action among the following cancers: breast, lung, prostate and head and neck. Lastly, for gastric cancer and colorectal there is no evidence of a correlation. The onco-suppressive efficacy of statins is mainly related to the histopathological and/or molecular characteristics of the tumor cells, which have different characteristics.

Statin Use and Survival Among Men Receiving Androgen-Ablative Therapies for Advanced Prostate Cancer: A Systematic Review and Meta-analysis

IMPORTANCE

Epidemiological evidence supports a role for statins in improving survival in advanced prostate cancer, particularly among men receiving androgen-ablative therapies.

OBJECTIVE

To study the association between statin use and survival among men with prostate cancer receiving androgen deprivation therapy (ADT) or androgen receptor axis-targeted therapies (ARATs).

DATA SOURCES

This systemic review and meta-analysis used sources from MEDLINE, EMBASE, Epub Ahead of Print, Cochrane Clinical Trials, Cochrane Systematic Reviews, and Web of Science from inception to September 6, 2022.

STUDY SELECTION

Observational studies reporting associations of concurrent statin use and survival outcomes (in hazard ratios [HRs]).

DATA EXTRACTION AND SYNTHESIS

Two authors independently abstracted all data. Summary estimates pooled multivariable HRs with 95% CIs using the generic inverse variance method with random-effects modeling. A priori specified subgroup and sensitivity analyses were undertaken, and heterogeneity, study quality, and publication bias were evaluated. Confidence in the evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach.

MAIN OUTCOMES AND MEASURES

Overall mortality and prostate cancer-specific mortality (PCSM).

RESULTS

Twenty-five cohorts of 119 878 men (65 488 statin users [55%]) with more than 74 416 deaths were included. Concurrent statin use was associated with a 27% reduction in the risk of overall mortality (HR, 0.73 [95% CI, 0.66-0.82]; I2 = 83%) and a 35% reduction in the risk of PCSM (HR, 0.65 [95% CI, 0.58-0.73]; I2 = 74%), with substantial heterogeneity in both estimates. Subgroup analyses identified a PCSM advantage associated with statins for men receiving ARATs compared with ADT alone (HR, 0.40 [95% CI, 0.30-0.55] vs 0.68 [95% CI, 0.60-0.76]; P = .002 for difference). Confidence in the evidence was rated low for both outcomes.

CONCLUSIONS AND RELEVANCE

The findings of this meta-analysis show that concurrent statin use was associated with reduced overall mortality and PCSM among men receiving androgen-ablative therapies for advanced prostate cancer. These findings are limited by the observational nature of the data and residual unexplained interstudy heterogeneity. Randomized clinical trials are warranted to validate these results.

Influence of statins in metastatic castration-resistant prostate cancer patients treated with new antiandrogen therapies: a systematic review and meta-analysis

Objective

To evaluate whether the addition of statins to the new antiandrogens (enzalutamide or abiraterone) affects overall survival in patients with metastatic castration-resistant prostate cancer.

Methods

We searched studies in English language including the keywords statins, overall survival, and metastatic castration-resistant prostate cancer, at PubMed^® (MEDLINE^®), Embase and Cochrane databases.

Results

A total of 195 articles were initially identified, but only four met the inclusion criteria and were selected for the meta-analysis. A total of 955 patients, 632 on the new antiandrogens only group, and 323 on the new antiandrogens + statins group, were analyzed. In all four studies the combination therapy (new antiandrogens + statin) was well tolerated, regardless of which new antiandrogens were used. Neither the type of statin nor the doses and duration of use were well specified in the studies. The combination therapy in metastatic castration-resistant prostate cancer was associated with an overall survival improvement, and a 46% reduction in death (hazard ratio of 0.54; 95%CI 0.34-0.87; p<0.01) in multivariate analysis.

Conclusion

There seems to be a clinical benefit with the association of statins to the new antiandrogens in patients with metastatic castration-resistant prostate cancer, suggesting longer overall survival with no important collateral effect. However, due to fragility of the studies available in the literature, we are not yet capable of recommending this combination of drugs in the clinical practice. Further randomized prospective studies are warranted to confirm these beneficial outcomes.