Statin Use and Prostate Cancer Survival in the Finnish Randomized Study of Screening for Prostate Cancer

Linkage of Clinical Trial Data to Routinely Collected Data Sources: A Scoping Review

Importance

Patients who participate in clinical trials generate valuable routinely collected data (eg, medical records, electronic health records, claims databases, disease registries, or vital statistics) through their routine interactions with the health care system before, during, and after the trial. When this routinely collected data is linked at the participant level, it can supplement active data collection in the trial and provide deeper insights into the benefits, risks, and costs of treatments.

Objective

To review clinical trials linked to routinely collected data in various countries, identifying the use cases and designs of these linkage studies.

Evidence Review

Research articles that reported the linkage of clinical trials to medical records, electronic health records, claims databases, disease registries, or vital statistics in their title or abstract were searched for in PubMed and MEDLINE. The search covered the period from January 1, 2016, through December 30, 2023. Opinion pieces, study protocols, or studies that involved interventions other than medications, dietary supplements, vaccines, devices, procedures, or diagnostics (eg, behavioral interventions) were excluded. Study eligibility and data extraction were performed independently by 2 reviewers to ensure the accuracy of findings.

Findings

Of the 990 abstracts initially screened, a full text review was conducted for 147 articles. In total, 71 studies were included in the results, including 42 medication, vaccine, and dietary supplement trials (59.2%) and 29 device, procedure, or diagnostic trials (40.8%). Of these 71 studies, 24 (32.4%) were conducted in the US. In 32 studies (45.1%), consent for linkage was obtained prospectively as part of the main trial, while 33 studies (46.5%) received a waiver of authorization from the respective ethical review boards. The most frequent use cases of linkage to were posttrial long-term follow-up (22 studies [31.0%]), capturing primary or secondary outcomes of trials (19 studies [26.8%]), validation of routinely collected data outcomes (17 studies [23.9%]), and measuring health care resource utilization and cost in trials (12 studies [16.9%]).

Conclusions and Relevance

This study found that the linkage of patients' clinical trial data to routinely collected data has been implemented in several trials for various use cases and that most studies obtained consent for linkage prospectively as part of the main trial or received a waiver of authorization from ethical review boards. These findings demonstrate the feasibility and provide an overview of the use cases for linking trials to routinely collected data.

Statin use and oncological outcomes in a propensity-matched cohort of nonmetastatic castration resistant prostate cancer patients of the ARAMIS trial

INTRODUCTION

While observational studies suggest favorable associations between statin use and prostate cancer (CaP) outcomes, data from randomized-controlled trials remain inconclusive. Our study explores the relationship between statin use and survival outcomes in the context of the phase III ARAMIS study, a trial of darolutamide in the treatment of nonmetastatic castration-resistant prostate cancer.

METHODS

We reviewed all 1,509 patients in the ARAMIS trial. Statin use was identified at baseline. Statin users were matched 1:2 with nonusers using a propensity score matching model. The primary endpoint was metastasis-free survival (MFS). Kaplan-Meier curves were plotted for MFS comparing statin users and nonusers across ARAMIS trial arms. A multivariate Cox proportional hazards model was fitted using the propensity-matched cohort and incorporating statin use and all covariates.

RESULTS

Of the 1,509 patients in ARAMIS, 334 (22.1%) were statin users. We matched 297 statin users to 550 nonusers. Characteristics appeared well balanced. Among nonusers, 331 (60.3%) and 219 (39.7%) were in the ARAMIS darolutamide and placebo arms, respectively. Among statin users, 179 (60.3%) and 118 (39.7%) were in the ARAMIS darolutamide and placebo arms, respectively. Overall, we found no significant difference in MFS between statin users and nonusers (HR 1.05, 95% CI 0.80-1.38 P = .72). However, we found significant interaction between statin use and ARAMIS trial arm. Specifically, statin use had a stronger association with MFS in the placebo arm (P = 0.024). However, this is likely coincidental and due to the statin-placebo patients having higher nodal positivity than the nonusers-placebo patients (14.3% vs. 5.5%). Statin use was similarly not associated with the secondary outcomes of PSA progression-free survival (P = 0.42), time-to-pain progression (P = 0.85), or overall survival (P = 0.15).

CONCLUSIONS

In our secondary analysis of the ARAMIS trial, statin users had similar MFS and secondary outcomes compared to nonusers. These results suggest pursuing further statin synergies with amide-based androgen receptor axis target agents may not be fruitful.

Statin Concentration in Prostatic Tissue is Subtype- and Dose-dependent

OBJECTIVE

To evaluate for the first time, comparative serum and prostate tissue concentrations of lipophilic and hydrophilic statins.

METHODS

After reviewing all patients who underwent radical prostatectomy between 1993 and 2019, we selected 80 patients taking atorvastatin (lipophilic) or rosuvastatin (hydrophilic) for cholesterol control and with available banked fresh-frozen tissue from the prostatectomy. Primary endpoint was serum and prostate statin concentration measured by HPLC-mass spectrometry analysis. Serum/prostate statin concentrations were compared between patients on atorvastatin and rosuvastatin, and patients receiving high- and low-dose statin, using the Mann-Whitney U test.

RESULTS

In total, 39 patients were taking atorvastatin and 41 were taking rosuvastatin. Thirty-eight and 42 were taking high- and low-dose statin, respectively. Statin concentration was measurable in the prostatic tissue of 15 patients (38.4%) taking atorvastatin (33.3% high-dose vs 42.8% low-dose) compared to 22 (53.6%) taking rosuvastatin (55% high-dose vs 52.3% low-dose). Median tissue concentration of rosuvastatin was greater than atorvastatin (3.98 ng/g vs 0.96 ng/g, P <.001). Dose-dependency was observed: median prostate concentration was higher in those taking high-dose versus low-dose statin for both atorvastatin (1.22 ng/g vs 0.79 ng/g, P = .69) and rosuvastatin (5.21 ng/g vs 1.99 ng/g, P <.001).

CONCLUSION

We have shown, for the first time, that lipophilic and hydrophilic statins can be measured in the prostate of patients with prostate cancer and that the concentrations are dependent on dose. Moreover, rosuvastatin, a hydrophilic statin, achieves a 4-fold higher concentration in the prostate.

β-blockers and statins: exploring the potential off-label applications in breast, colorectal, prostate, and lung cancers

Despite advances in cancer treatment, current cancer incidence and prevalence still demand multimodal treatments to enhance survival and clinical outcomes. Drugs used in cardiology, such as β-blockers and statins have gained attention for their potential roles in oncology. This review focused on their possible complementary use in solid tumors, including breast, colorectal, lung, and prostate cancers. The involvement of the autonomic nervous system in promoting tumor growth can be disrupted by β-blockers, potentially hindering cancer progression. Statins, known for their pleiotropic effects, may also inhibit cancer growth by reducing cholesterol availability, a key factor in cell proliferation. We will provide an update on the impact of these therapies on cancer treatment and surveillance, discuss the underlying mechanisms, and explore their effects on the heart, contributing to the growing field of cardio-oncology.

Evaluating the impact of pre-diagnostic use of statins and testosterone replacement therapy on mortality outcomes in older men with hormone-related cancers: Surveillance, Epidemiology, and End Results-Medicare 2007-2015

BACKGROUND

The link between the pre-diagnostic use of statins and testosterone replacement therapy and their impact on hormone-related cancers, prostate cancer, colorectal cancer, and male breast cancer survival remains a topic of controversy. Further, there is a knowledge gap concerning the joint effects of statins and testosterone replacement therapy on hormone-related cancer survival outcomes.

OBJECTIVE

To examine the independent and joint effects of pre-diagnostic use of statins and testosterone replacement therapy on the risk of all-cause and cause-specific mortality among older men diagnosed with hormone-related cancers, including prostate cancer, colorectal cancer, and male breast cancer.

METHODS

In 41,707 men (≥65 years) of Surveillance, Epidemiology, and End Results-Medicare 2007-2015, we identified 31,097 prostate cancer, 10,315 colorectal cancer, and 295 male breast cancer cases. Pre-diagnostic prescription of statins and testosterone replacement therapy was ascertained and categorized into four groups (Neither users, statins alone, testosterone replacement therapy alone, and Dual users). Multivariable-adjusted Cox proportional hazards and competing-risks (Fine-Gray subdistribution hazard) models were conducted.

RESULTS

No significant associations were found in Cox-proportional hazard models for hormone-related cancers. However, in the Fine-Gray competing risk models among high-grade hormone-related cancers, statins alone had an 11% reduced risk of hormone-related cancer-specific death (hazard ratio: 0.89; 95% confidence interval: 0.81-0.99; p 0.0451). In the prostate cancer cohort with both statistical models, the use of testosterone replacement therapy alone had a 24% lower risk of all-cause death (hazard ratio: 0.76; 95% confidence interval: 0.59-0.97; p 0.0325) and a 57% lower risk of prostate cancer-specific death (hazard ratio: 0.43; 95% confidence interval: 0.24-0.75; p 0.0029). Similar inverse associations were found among aggressive prostate cancer cases with testosterone replacement therapy alone and statins alone. No significant associations were found in the colorectal cancer and male breast cancer sub-groups.

CONCLUSION

Pre-diagnostic use of statins and testosterone replacement therapy showed a survival benefit with reduced mortality in high-grade hormone-related cancer patients (only statins) and aggressive prostate cancer patients in both statistical models. Findings of testosterone replacement therapy use in aggressive prostate cancer settings could facilitate clinical trials. Further studies with extended follow-up periods are needed to substantiate these findings.

Patient Demographics and Major Adverse Cardiovascular Events after Androgen Deprivation Therapy for Prostate Cancer

Background

The association between patient demographics and CV events after ADT using real-world data was evaluated. In addition to encompassing >30 times more patients than all previous MACE studies, this is the first study, to the best of our knowledge, to include a comprehensive listing of many demographic factors from one large, recent US dataset over a long period of time.

Materials and Methods

The retrospective analysis of data in the Decision Resources Group (now Clarivate) Real World Evidence repository, representing >300M US patients from 1991 to 2020 across all US regions, was performed. Patients with PCa receiving ≥1 ADT injection were included. MACE risk after ADT initiation was evaluated for demographic and potential PCa-related risk factors. Kaplan-Meier survival curves were constructed, and Cox regression was used to evaluate the association between MACE risk and demographic/PCa-related risk factors.

Results

Overall, MACE risk was slightly lower in the first year after ADT initiation (3.9%) vs. years 2-4 (∼5.2%). In a multivariate Cox model, MACE risk after ADT initiation was significantly higher for older vs. younger patients (adjusted HR per increasing year = 1.08, 95% CI: 1.07-1.09), men with a history of MACE vs. without (HR = 2.22, 95% CI: 1.72-2.88), men with very low BMI vs. normal or high BMI (HR for decreasing BMI per kg/m2 = 1.02, 95% CI: 1.01-1.03), White vs. Black patients (HR = 1.30, 95% CI: 1.08-1.55), and patients who did not use statins vs. those who did (HR = 1.13, 95% CI: 1.00-1.27). Of the PCa-related risk factors, MACE risk after ADT initiation was significantly higher for oncology vs. urology treatment setting (HR = 2.47, 95% CI: 2.12-2.88), patients with baseline metastasis vs. those without (HR = 2.30, 95% CI: 1.72-3.07), and patients treated with antagonists vs. agonists (HR = 1.62, 95% CI: 1.25-2.10).

Conclusions

Demographic factors are important contributors to increased MACE risk for men with PCa on ADT. Clinicians should monitor risk factors and modify if possible.

Overcoming statin resistance in prostate cancer cells by targeting the 3-hydroxy-3-methylglutaryl-CoA-reductase

Prostate cancer is the most prevalent malignancy in men. While diagnostic and therapeutic interventions have substantially improved in recent years, disease relapse, treatment resistance, and metastasis remain significant contributors to prostate cancer-related mortality. Therefore, novel therapeutic approaches are needed. Statins are inhibitors of the 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the rate-limiting enzyme of the mevalonate pathway which plays an essential role in cholesterol homeostasis. Numerous preclinical studies have provided evidence for the pleiotropic antitumor effects of statins. However, results from clinical studies remain controversial and have shown substantial benefits to even no effects on human malignancies including prostate cancer. Potential statin resistance mechanisms of tumor cells may account for such discrepancies. In our study, we treated human prostate cancer cell lines (PC3, C4-2B, DU-145, LNCaP) with simvastatin, atorvastatin, and rosuvastatin. PC3 cells demonstrated high statin sensitivity, resulting in a significant loss of vitality and clonogenic potential (up to - 70%; p < 0.001) along with an activation of caspases (up to 4-fold; p < 0.001). In contrast, C4-2B and DU-145 cells were statin-resistant. Statin treatment induced a restorative feedback in statin-resistant C4-2B and DU-145 cells through upregulation of the HMGCR gene and protein expression (up to 3-folds; p < 0.01) and its transcription factor sterol-regulatory element binding protein 2 (SREBP-2). This feedback was absent in PC3 cells. Blocking the feedback using HMGCR-specific small-interfering (si)RNA, the SREBP-2 activation inhibitor dipyridamole or the HMGCR degrader SR12813 abolished statin resistance in C4-2B and DU-145 and induced significant activation of caspases by statin treatment (up to 10-fold; p < 0.001). Consistently, long-term treatment with sublethal concentrations of simvastatin established a stable statin resistance of a PC3SIM subclone accompanied by a significant upregulation of both baseline as well as post-statin HMGCR protein (gene expression up to 70-fold; p < 0.001). Importantly, the statin-resistant phenotype of PC3SIM cells was reversible by HMGCR-specific siRNA and dipyridamole. Our investigations reveal a key role of a restorative feedback driven by the HMGCR/SREBP-2 axis in statin resistance mechanisms of prostate cancer cells.

Allopurinol and prostate cancer survival in a Finnish population-based cohort

BACKGROUND

Allopurinol is gout medication that inhibits uric acid formation. Its possible anti-carcinogenic properties have been under research in past years. Studies based on Taiwanese registries showed that long term allopurinol use might reduce prostate cancer (PCa) incidence. However, our studies based on Finnish registries did not support those findings. In this study, we evaluate whether allopurinol use is associated with prostate cancer-specific survival (CSS) or overall survival (OS) in a Finnish population-based cohort.

METHODS

The study cohort was originally enrolled for the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC). We included all newly diagnosed PCa cases during 1996-2015, 9252 men in total. Information on allopurinol purchases was from the national prescription registry of the Social Insurance Institution of Finland. Information about deaths, treatments, and use of other medications was obtained from registries, and tumor stage and PSA at diagnosis from medical records. Follow-up started at diagnosis, and we analysed separately two endpoints: PCa-specific death and overall death. We used an extended Cox regression with adjustment for age at diagnosis, Charlson comorbidity index, FinRSPC trial arm, use of other drugs and EAU PCa risk group.

RESULTS

During a median follow-up of 9.86 years, 2942 deaths occurred, including 883 from PCa. There was no difference in CSS between allopurinol user and non-users, but allopurinol users had lower OS (multivariable-adjusted hazard ratio 1.77; 95% CI: 1.57-2.00). However, this decrease in OS was mitigated along with increasing intensity of allopurinol use.

CONCLUSIONS

We found no marked difference in CSS by allopurinol use. Allopurinol users had lower OS but there were no significant differences by duration or intensity of allopurinol use. Allopurinol use may not have anticancer effects against prostate cancer; instead, it may be a surrogate for metabolic problems causing shorter OS among men with PCa.

Statin use and outcomes of oncological treatment for castration-resistant prostate cancer

To compare the effect of statin use in relation to castration-resistant prostate cancer (CRPC) treatment, we assessed the risk of ADT-treated PCa-patients to initiate CRPC treatment by statin use and the outcomes of CRPC treatment by statin use. Our study cohort consisted of 1169 men who participated in the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) and initiated androgen deprivation therapy (ADT) during the follow-up (1996-2017). Statin use was associated with slightly decreased risk of initiating CRPC treatment (HR 0.68; 95% CI 0.47-0.97) with a 5.7 years' median follow-up until CRPC for non-users and 7.5 years for statin users. The risk of discontinuation of first or second line CRPC treatment due to inefficacy was not modified by statin use and the results remained similar in subgroup analysis assessing separately patients treated with taxans or androgen receptor signaling inhibitors. We observed an inverse association between statin use and the risk of initiation of the CRPC treatment. No beneficial risk modification by statin use during CRPC treatment was observed. These results suggest that statins might be beneficial during hormone-sensitive phase but not in the later phases of prostate cancer treatment.

Establishment and validation of serum lipid-based nomogram for predicting the risk of prostate cancer

BACKGROUND

This study aimed to explore the value of combined serum lipids with clinical symptoms to diagnose prostate cancer (PCa), and to develop and validate a Nomogram and prediction model to better select patients at risk of PCa for prostate biopsy.

METHODS

Retrospective analysis of 548 patients who underwent prostate biopsies as a result of high serum prostate-specific antigen (PSA) levels or irregular digital rectal examinations (DRE) was conducted. The enrolled patients were randomly assigned to the training groups (n = 384, 70%) and validation groups (n = 164, 30%). To identify independent variables for PCa, serum lipids (TC, TG, HDL, LDL, apoA-1, and apoB) were taken into account in the multivariable logistic regression analyses of the training group, and established predictive models. After that, we evaluated prediction models with clinical markers using decision curves and the area under the curve (AUC). Based on training group data, a Nomogram was developed to predict PCa.

RESULTS

210 (54.70%) of the patients in the training group were diagnosed with PCa. Multivariate regression analysis showed that total PSA, f/tPSA, PSA density (PSAD), TG, LDL, DRE, and TRUS were independent risk predictors of PCa. A prediction model utilizing a Nomogram was constructed with a cut-off value of 0.502. The training and validation groups achieved area under the curve (AUC) values of 0.846 and 0.814 respectively. According to the decision curve analysis (DCA), the prediction model yielded optimal overall net benefits in both the training and validation groups, which is better than the optimal net benefit of PSA alone. After comparing our developed prediction model with two domestic models and PCPT-RC, we found that our prediction model exhibited significantly superior predictive performance. Furthermore, in comparison with clinical indicators, our Nomogram's ability to predict prostate cancer showed good estimation, suggesting its potential as a reliable tool for prognostication.

CONCLUSIONS

The prediction model and Nomogram, which utilize both blood lipid levels and clinical signs, demonstrated improved accuracy in predicting the risk of prostate cancer, and consequently can guide the selection of appropriate diagnostic strategies for each patient in a more personalized manner.

The utility of 3D models to study cholesterol in cancer: Insights and future perspectives

Cholesterol remains a vital molecule required for life; however, increasing evidence exists implicating cholesterol in cancer development and progression. Numerous studies investigating the relationship between cholesterol and cancer in 2-dimensional (2D) culture settings exist, however these models display inherent limitations highlighting the incipient need to develop better models to study disease pathogenesis. Due to the multifaceted role cholesterol plays in the cell, researchers have begun utilizing 3-dimensional (3D) culture systems, namely, spheroids and organoids to recapitulate cellular architecture and function. This review aims to describe current studies exploring the relationship between cancer and cholesterol in a variety of cancer types using 3D culture systems. We briefly discuss cholesterol dyshomeostasis in cancer and introduce 3D in-vitro culture systems. Following this, we discuss studies performed in cancerous spheroid and organoid models that focused on cholesterol, highlighting the dynamic role cholesterol plays in various cancer types. Finally, we attempt to provide potential gaps in research that should be explored in this rapidly evolving field of study.

Statin Use Is Associated with Better Prognosis of Patients with Prostate Cancer after Definite Therapies: A Systematic Review and Meta-Analysis of Cohort Studies

OBJECTIVE

Although the prognostic effect of statins on patients with prostate cancer (PCa) has been frequently evaluated, a consistent result is still lacking. We aimed to evaluate the association between statin use and mortality among patients with PCa after definite therapies.

METHODS

A systematic search of PubMed and other databases for cohort studies about the effect of statins on patients with PCa was performed until April 2022. Meta-analysis was performed using R software version 4.1.2.

RESULTS

24 cohort studies involving 369, 206 participants were finally included. We found statin use significantly reduced the risk of prostate cancer-specific mortality (PCSM) with a pooled hazard ratio (pHR) = 0.76 (95% CI: 0.69-0.84, 18 studies), especially for postdiagnostic statin users: pHR = 0.81 (95% CI: 0.77-0.85) and patients who accepted androgen deprivation therapy (ADT): pHR = 0.69 (95% CI: 0.59-0.81). Statin use was also associated with a 24% reduction in the risk of all-cause mortality (ACM): pHR = 0.76 (95% CI: 0.68-0.85, 17 studies), especially for postdiagnostic statin users: pHR = 0.81 (95% CI: 0.78-0.85) and patients treated with ADT: pHR = 0.72 (95% CI: 0.63-0.82) or radiotherapy (RT): pHR = 0.68 (95% CI: 0.50-0.93).

CONCLUSION

In conclusion, the use of statins could promote the prognosis of patients with PCa, especially for postdiagnostic users. For patients who received either ADT or radical prostatectomy (RP), statin use could decrease the PCSM. As for those who received either ADT or RT, statin use could decrease the ACM.

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.

Effects of metformin and statins on outcomes in men with castration-resistant metastatic prostate cancer: Secondary analysis of COU-AA-301 and COU-AA-302

BACKGROUND

The associations of metformin and statins with overall survival (OS) and prostate specific antigen response rate (PSA-RR) in trials in metastatic castration-resistant prostate cancer remain unclear.

OBJECTIVE

To determine whether metformin or statins ± abiraterone acetate plus prednisone/prednisolone (AAP) influence OS and PSA-RR.

DESIGN, SETTING AND PARTICIPANT

COU-AA-301 and COU-AA-302 patients were stratified by metformin and statin use. Cox proportional hazards models were used to estimate hazards ratio (HR) stratified by concomitant medications, and a random effects model was used to pool HR. We compared PSA-RR using Chi χ² test.

RESULTS

In COU-AA-301-AAP, metformin was associated with improved PSA-RR (41.1% versus 28.6%) but not prolonged OS. In COU-AA-301-placebo-P, there was no association between metformin and prolonged OS or PSA-RR. In COU-AA-302-AAP, metformin was associated with prolonged OS (adjHR 0.69, 95% CI 0.48-0.98) and improved PSA-RR (72.7% versus 60.0%). In COU-AA-302-P, metformin was associated with prolonged OS (adjHR 0.66, 95% CI 0.47-0.93). In pooled analysis, OS was prolonged among those treated with metformin (pooled HR 0.77, 95% CI 0.62-0.95).In COU-AA-301-AAP, statins were associated with an improved OS (adjHR 0.76, 95% CI 0.62-0.93), while there was no difference in COU-AA-301-P. There was no association with statins and OS in either COU-AA-302 groups. When pooling HR, OS was prolonged among those treated with statins (pooled HR 0.78, 95% CI 0.68-0.88).

CONCLUSION

Within the limitations of post-hoc sub-analyses, metformin and statins are associated with a prolonged OS and increased PSA-RR, particularly in combination with AAP.

Inverse Association between Statin Use and Cancer Mortality Relates to Cholesterol Level

Simple Summary

We observed that the inverse association between statin use and cancer mortality is limited to men with a reduction in cholesterol after the commencement of statins. These findings demonstrate that the observed inverse association between the use of statins and mortality from cancer is related to cholesterol level. To our knowledge, this is the first study to evaluate the separate effects of cholesterol level and statin use on cancer mortality.

Abstract

Statins have been associated with a decreased cancer mortality. However, cholesterol level as such may modify the risk of cancer death. To clarify the complex interplay between statins, cholesterol level, and cancer mortality, we conducted a comprehensive analysis to separate the effects of cholesterol level and statin medication on cancer mortality. Our study population consisted of 16,924 men participating in the Finnish Randomized Study of Screening for Prostate Cancer with at least one cholesterol measurement during follow-up (1996–2017). Cox proportional regression was used to estimate hazard ratios. In total, 1699 cancer deaths were observed during the median follow-up of 19 years. When statins’ association with the risk of cancer death was estimated without adjustment for cholesterol level, statin use was associated with a lowered cancer mortality (HR 0.87; 95% CI 0.79–0.97) compared to non-users. However, with further adjustment for total cholesterol level, statin use was no longer associated with a lower cancer mortality (HR 1.08; 95% CI 0.97–1.20). Upon stratified analysis, statin use was associated with a decreased cancer mortality only if the total cholesterol level decreased after the initiation of statin use (HR 0.66; 95% CI 0.58–0.76). The inverse association between statin use and cancer mortality is limited to men with a reduction in total cholesterol level after the commencement of statins, i.e., statin use is associated with a lowered cancer mortality only if the total cholesterol level decreases. This suggests that the effect of statin use on cancer mortality relates to the decreased total cholesterol level.

The Association of Prediagnostic Statin Use with Aggressive Prostate Cancer from the Multiethnic Cohort Study

BACKGROUND

There is a growing body of evidence supporting the protective effect of statins on the risk of prostate cancer, in particular aggressive disease. Past research has mostly been conducted in North American cohorts of White men.

METHODS

In the multiethnic cohort (MEC), we investigated the association of prediagnostic statin use with the incidence and mortality of prostate cancer across five racial/ethnic groups (White, African American, Japanese American, Latino, and Native Hawaiian).

RESULTS

Among 31,062 male participants who completed a detailed medication questionnaire, 31.4% reported use of statins, 2,748 developed prostate cancer, and 261 died from the disease. After adjusting for potential confounders, prediagnostic statin use was associated with a 32% lower risk of fatal prostate cancer [95% confidence interval (CI) = 0.50-0.91], with the inverse association suggested consistently across the five racial/ethnic groups. Moreover, an 11% lower risk of aggressive prostate cancer (95% CI = 0.76-1.03) was observed in statin users than in nonusers. We found no statistically significant association between prediagnostic statin use and total prostate cancer or nonaggressive disease. Prediagnostic statin use was suggestively associated with a 19% reduction in prostate cancer-specific mortality (95% CI = 0.59-1.10) and an 8% reduction in all-cause mortality (95% CI = 0.79-1.07).

CONCLUSIONS

In the MEC, prediagnostic use of statin was associated with lower risks of aggressive forms of prostate cancer.

IMPACT

Our findings provide further support for the potential benefits of statins in reducing the risk and mortality of prostate cancer, especially aggressive disease.

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.

Improved survival with post-diagnostic metformin and statin use in a racially diverse cohort of US Veterans with advanced prostate cancer

OBJECTIVE

To examine the association between post-diagnostic metformin or statin use with all-cause and prostate cancer (PCa)-specific mortality in men with advanced prostate cancer.

METHODS

Our study consisted of 4572 men (Black = 1352, White = 3192, Other Race = 28) diagnosed with advanced cancer (T4/M1/N1) between 1999 and 2013 in the Veteran Health Administration. The association between post-diagnostic (1) metformin and (2) statin use with all-cause and PCa-specific mortality was examined using multivariable, time-varying Cox Proportional Hazard Models. In a secondary analysis, models were stratified by race.

RESULTS

Post-diagnostic metformin use was associated with a reduced risk of all-cause (Hazard Ratio (HR) 0.84, 95% Confidence Interval (CI): 0.73, 0.96) and PCa-specific death (HR: 0.76, 95% CI: 0.63, 0.91). In stratified analyses, the inverse association between post-diagnostic metformin use and both all-cause PCa-specific mortality was limited to White men. Post-diagnostic statin use was associated with a reduced risk of all-cause (HR: 0.75, 95% CI: 0.68, 0.83) and PCa-specific mortality (HR: 0.72; 95% CI: 0.64, 0.81). In stratified analyses, similar inverse associations were observed for post-diagnostic statin use and all-cause and PCa-specific mortality in both Black and White men.

CONCLUSION

Post diagnostic metformin and statin use may prevent progression to lethal prostate cancer in men with advanced prostate cancer.

Statins and prostate cancer-hype or hope? The epidemiological perspective

BACKGROUND

Men using cholesterol-lowering statin medications have been found to have lower risks of both advanced and fatal prostate cancer in multiple registry-based studies and prospective cohort studies. Statin use has also been associated with longer survival among men already diagnosed with prostate cancer. Mechanisms responsible for purported anti-cancer effects of statins are not well understood but may offer insight into prostate cancer biology.

METHODS

We summarise epidemiological data from studies of statins and prostate cancer and discuss to what extent these findings can be interpreted as causal. Additionally, lipid-mediated and non-lipid-mediated mechanisms that may contribute to potential anti-cancer effects of statins are reviewed. Finally, we consider treatment settings and molecular subgroups of men who might benefit more than others from statin use in terms of prostate cancer-specific outcomes.

RESULTS

Data from prospective observational studies generally reported a lower risk of fatal prostate cancer among statin users. There is some evidence for serum cholesterol-lowering as an indirect mechanism linking statins with advanced and fatal prostate cancer. Window-of-opportunity clinical trials show measurable levels of statins in prostate tissue highlighting potential for direct effects, whilst observational data suggest possible statin-driven modulation of prostate microenvironment inflammation. Additionally, emerging data from registry studies support a potential role for statins within the context of androgen deprivation therapy and anti-androgen treatment.

CONCLUSION

Prospective and registry-based studies support a lower risk of advanced and fatal prostate cancer in statin users relative to non-users, as well as better outcomes among prostate cancer patients. The few randomised-controlled trials conducted so far have short follow-up, lack identified molecular subgroups, and do not provide additional support for the observational results. Consequently, additional evidence is required to determine which men may experience greatest benefit in terms of prostate cancer-specific outcomes and how statin effects may vary according to molecular tumour characteristics.

Statins downregulate YAP and TAZ and exert anti-cancer effects in canine mammary tumour cells

Canine mammary tumours (CMTs) are the most common neoplasms in intact bitches, and few chemotherapeutic options are available for highly invasive and metastatic tumours. Recent studies have shown the potential involvement of dysregulated Hippo signalling in CMT development and progression. Statins can activate the Hippo pathway by blocking protein geranylgeranylation (GGylation), resulting in decreased expression and activity of the transcriptional co-activators YAP and TAZ. In this study, we therefore sought to determine if statins could exert anti-cancer effects in CMT cells. Our results demonstrate that Atorvastatin and Fluvastatin are cytotoxic to two CMT cell lines (CMT9 and CMT47), with ED50 values ranging from 0.95 to 23.5 μM. Both statins acted to increase apoptosis and promote cell cycle arrest. Both statins also decreased YAP and TAZ expression and reduced the mRNA levels of key Hippo transcriptional target genes known to be involved in breast cancer progression and chemoresistance (CYR61, CTGF and RHAMM). Moreover, both statins effectively inhibited cell migration and anchorage independent growth, but did not influence matrix invasion. Taken together, our results demonstrate for the first time that statins act upon the Hippo pathway in CMT cells to counteract several molecular and cellular hallmarks of cancer. These findings suggest that targeting the Hippo pathway with statins represents a novel and promising approach for the treatment canine mammary gland cancers.

Population-wide impacts of aspirin, statins, and metformin use on prostate cancer incidence and mortality

We evaluated the association between aspirin, statins, and metformin use and prostate cancer (PC) incidence and mortality using a large population-based dataset. 388,760 men who participated in national health screening program in Korea during 2002–2003 were observed from 2004 to 2013. Hazard ratios of aspirin, statins, and metformin use for PC incidence and PC mortality were calculated with adjustment for simultaneous drug use. Cumulative use of each drug was inserted as time-dependent variable with 2-year time windows. Aspirin use ≥ 1.5 year (per 2-year) was associated with borderline decrease in PC mortality when compared to non-users (adjusted hazard ratio [aHR] 0.71, 95% confidence interval [CI] 0.50–1.02). Statins use was not associated with either PC incidence or PC mortality. Metformin ever-use was associated with decreased PC incidence compared with non-diabetics (aHR 0.86, 95% CI 0.77–0.96). Diabetics who were not using metformin or using low cumulative doses had higher PC mortality than non-diabetics (aHR 2.01, 95% CI 1.44–2.81, and aHR 1.70, 95% CI 1.07–2.69, respectively). However, subjects with higher cumulative doses of metformin did not show increased PC mortality. In conclusion, metformin use was associated with lower PC incidence. Use of aspirin and that of metformin among diabetic patients were associated with lower PC mortality.

Adjuvant Low-dose Statin Use after Radical Prostatectomy: The PRO-STAT Randomized Clinical Trial

PURPOSE

Statin use is reportedly associated with the risk of prostate cancer, outcomes after treatment, and prostate cancer-specific mortality. We sought to determine the efficacy of adjuvant atorvastatin in prostate cancer after radical prostatectomy.

PATIENTS AND METHODS

In this randomized, double-blind trial, we assigned patients with pathologic high-risk prostate cancer to receive either low-dose atorvastatin (20 mg/day, n = 183) or placebo (n = 181) for 1 year after radical prostatectomy. The primary endpoint was the 1-year biochemical recurrence rate. The secondary endpoints included the 5-year biochemical recurrence-free survival and changes in lipid, testosterone, and sex hormone binding globulin levels.

RESULTS

From October 2012 through January 2019, a total of 364 patients underwent randomization. Among 59 total primary end points, 30 (16.4%) and 29 (16.0%) occurred in the atorvastatin and placebo groups, respectively. Atorvastatin did not significantly reduce the primary endpoint of 1-year biochemical recurrence [HR, 0.96; 95% confidence interval (CI), 0.58-1.60]. During a median follow-up of 24 months, 131 patients experienced biochemical recurrence (68 in the atorvastatin group and 63 in the placebo group), representing Kaplan-Meier estimated event rates of 24.0% and 25.4% in the atorvastatin and placebo groups, respectively, at 24 months (HR, 1.00; 95% CI, 0.71-1.41). We observed no significant between-group differences in the testosterone and sex hormone binding globulin levels.

CONCLUSIONS

Among patients with high-risk pathologic features after radical prostatectomy for prostate cancer, 1-year adjuvant use of atorvastatin was not associated with a lower risk of disease recurrence compared with that for placebo. (ClinicalTrials.gov number, NCT01759836).See related commentary by Murtola and Siltari, p. 4947.

Statin Type and Cancer Outcomes in Patients with Diabetes Type 2 and Solid Tumors

OBJECTIVE

Type 2 diabetes mellitus (T2DM) affects 10% of Americans and is associated with an increased incidence of cancer. Statins are first-line cholesterol-lowering medications in the treatment of hyperlipidemia. Several studies have demonstrated a relationship between statin use and reduced cancer incidence. We examined the cancer benefits of statin subtypes, with specific attention to disease-free survival (DFS) and overall survival (OS).

METHODS

This retrospective review included adults with T2DM diagnosed with solid tumors at Roswell Park Cancer Institute in Buffalo, NY, USA (2003-2010). Individuals with gestational diabetes, incomplete records, or diagnosed with rare solid tumors were excluded. Follow-up began at the date of diagnosis and ended with the first confirmed recurrence, death, or loss of contact. Demographics were assessed by Chi-square, Kaplan-Meier survival analyses, and Cox proportional hazards regression.

FINDINGS

Overall, 1102 patients met inclusion criteria, 52.1% of the study participants were female, and 578 participants (52.5%) died during the follow-up period which ranged from 0 to 156 months. Hydrophilic statin use was associated with improved DFS at 5-year follow-up (41.0% vs. 36.9%, P = 0.0077) compared to lipophilic statin use. Multivariate regression revealed that hydrophilic statins were associated with improved DFS (hazard ratio [HR]: 0.706, 95% confidence interval [CI]: 0.526-0.947) and OS (HR: 0.685, 95% CI: 0.503-0.934). Pravastatin was associated with improved OS (HR: 0.674, 95% CI: 0.471-0.964).

CONCLUSION

In patients with T2DM and cancer, hydrophilic statins, and pravastatin in particular, are associated with improved DFS as well as OS. Further research examining the cancer-specific effects of hydrophilic and lipophilic statins is needed to better understand their beneficial effects.

Prostate cancer prognosis after initiation of androgen deprivation therapy among statin users. A population-based cohort study

PURPOSE

Statins' cholesterol-lowering efficacy is well-known. Recent epidemiological studies have found that inhibition of cholesterol synthesis may have beneficial effects on prostate cancer (PCa) patients, especially patients treated with androgen deprivation therapy (ADT). We evaluated statins' effect on prostate cancer prognosis among patients treated with ADT.

MATERIALS AND METHODS

Our study population consisted of 8253 PCa patients detected among the study population of the Finnish randomized study of screening for prostate cancer. These were limited to 4428 men who initiated ADT during the follow-up. Cox proportional regression model adjusted for tumor clinical characteristics and comorbidities was used to estimate hazard ratios for risk of PSA relapse after ADT initiation and prostate cancer death.

RESULTS

During the median follow-up of 6.3 years after the ADT initiation, there were 834 PCa deaths and 1565 PSA relapses in a study cohort. Statin use after ADT was associated with a decreased risk of PSA relapse (HR 0.73, 95% CI 0.65-0.82) and prostate cancer death (HR 0.82; 95% CI 0.69-0.96). In contrast, statin use defined with a one-year lag (HR 0.89, 95% CI 0.76-1.04), statin use before ADT initiation (HR 1.12, 95% CI 0.96-1.31), and use in the first year on ADT (HR 1.02, 95% CI 0.85-1.24) were not associated with prostate cancer death, without dose dependency.

CONCLUSION

Statin use after initiation of ADT, but not before, was associated with improved prostate cancer prognosis.

Statins in risk-reduction and treatment of cancer

Statins, which are competitive inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, reduce cholesterol blood levels and the risk of developing cardiovascular diseases and their related complications. In addition to this main activity, statins show pleiotropic effects such as antioxidant, anti-inflammatory and antiproliferative properties, with applications in many pathologies. Based on their antiproliferative properties, in vitro and in vivo studies have investigated their effects on various types of cancer (i.e., breast cancer, prostate cancer, colorectal cancer, ovarian cancer, lung cancer) with different genetic and molecular characteristics. Many positive results were obtained, but they were highly dependent on the physiochemical properties of the statins, their dose and treatment period. Combined therapies of statins and cytotoxic drugs have also been tested, and synergistic or additive effects were observed. Moreover, observational studies performed on patients who used statins for different pathologies, revealed that statins reduced the risk of developing various cancers, and improved the outcomes for cancer patients. Currently, there are many ongoing clinical trials aimed at exploring the potential of statins to lower the mortality and the disease-recurrence risk. All these results are the foundation of new treatment directions in cancer therapy.

Effect of simvastatin on cell proliferation and Ras activation in canine tumour cells

Statins are inhibitors of the mevalonate cascade that is responsible for cholesterol biosynthesis and the formation of intermediate metabolites, farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP) used in the prenylation of proteins. Although statins are widely used in the treatment of hypercholesterolemia, recent studies suggest that they also inhibit proliferation of tumour cells by reducing prenylation of small GTP-binding proteins, such as, Ras. This study aimed to evaluate the effect of simvastatin on cell proliferation and Ras activation in various canine tumour cell lines, including hemangiosarcoma (HSA), melanoma, and lymphoma cell lines. Simvastatin inhibited cell proliferation of all cell lines tested in a concentration- and time-dependent manner, but the susceptibilities were different amongst the cell lines. Simvastatin induced apoptotic cell death via activation of caspase-3 and cell cycle arrest. The cytotoxic effects of simvastatin were attenuated by GGPP and FPP. Simvastatin decreased the amount of prenylated Ras and GTP-bound Ras in HSA and melanoma cell lines, but not in lymphoma cell lines. These results indicate that simvastatin induces cytotoxic effects through the depletion of GGPP and FPP in a variety of canine tumour cells, whereas multiple mechanisms are involved in the effects. Further study is required to elucidate the underlying mechanisms of simvastatin-induced cytotoxic effects in a variety of canine tumour cells.

Targeting SREBP-2-Regulated Mevalonate Metabolism for Cancer Therapy

Recently, targeting metabolic reprogramming has emerged as a potential therapeutic approach for fighting cancer. Sterol regulatory element binding protein-2 (SREBP-2), a basic helix-loop-helix leucine zipper transcription factor, mainly regulates genes involved in cholesterol biosynthesis and homeostasis. SREBP-2 binds to the sterol regulatory elements (SREs) in the promoters of its target genes and activates the transcription of mevalonate pathway genes, such as HMG-CoA reductase (HMGCR), mevalonate kinase and other key enzymes. In this review, we first summarized the structure of SREBP-2 and its activation and regulation by multiple signaling pathways. We then found that SREBP-2 and its regulated enzymes, including HMGCR, FPPS, SQS, and DHCR4 from the mevalonate pathway, participate in the progression of various cancers, including prostate, breast, lung, and hepatocellular cancer, as potential targets. Importantly, preclinical and clinical research demonstrated that fatostatin, statins, and N-BPs targeting SREBP-2, HMGCR, and FPPS, respectively, alone or in combination with other drugs, have been used for the treatment of different cancers. This review summarizes new insights into the critical role of the SREBP-2-regulated mevalonate pathway for cancer and its potential for targeted cancer therapy.

Uptake of high-density lipoprotein by scavenger receptor class B type 1 is associated with prostate cancer proliferation and tumor progression in mice

High-density lipoprotein (HDL) metabolism is facilitated in part by scavenger receptor class B, type 1 (SR-B1) that mediates HDL uptake into cells. Higher levels of HDL have been associated with protection in other diseases, however, its role in prostate cancer is not definitive. SR-B1 is up-regulated in prostate cancer tissue, suggesting a possible role of this receptor in tumor progression. Here, we report that knockout (KO) of SR-B1 in both human and mouse prostate cancer cell lines through CRISPR/Cas9-mediated genome editing reduces HDL uptake into the prostate cancer cells and reduces their proliferation in response to HDL. In vivo studies using syngeneic SR-B1 WT (SR-B1+/+) and SR-B1 KO (SR-B1-/-) prostate cancer cells in WT and apolipoprotein-AI KO (apoA1-KO) C57BL/6J mice revealed that WT hosts, containing higher levels of total and HDL-cholesterol, grew larger tumors than apoA1-KO hosts with lower levels of total and HDL-cholesterol. Furthermore, SR-B1-/- prostate cancer cells formed smaller tumors in WT hosts than SR-B1+/+ cells in the same host model. Increased tumor volume was overall associated with reduced survival. We conclude that knocking out SR-B1 in prostate cancer tumors reduces HDL-associated increases in prostate cancer cell proliferation and disease progression.

Impact of statin use on cancer-specific mortality and recurrence: A meta-analysis of 60 observational studies

This meta-analysis mainly summarized the studies reporting an association between statin use and cancer-specific mortality and recurrence or progression of cancer patients.We systematically searched for studies about the statin used in cancer patients in electronic databases, including PubMed, Web of Science, Cochrane, Clinical Trials, from inception through the November 2019. A total of 60 studies which included 953,177 participants were eligible with 233,322 cancer patients used statin. Our analysis selected studies presented with outcome based on hazard ratios (HRs) and 95% confidence intervals (CIs) of cancer-specific mortality and cancer recurrence-free survival or progression-free survival. Heterogeneity between the studies was examined using I statistics, and sensitivity analyses were conducted to assess the robustness of the findings. All statistical analyses were performed using RevMan software (version 5.3).The use of statin was potentially associated with a decline in cancer-specific mortality in cancer patients (HR = 0.78; 95% CI: 0.74, 0.84; n = 39; I = 85%). Furthermore, statin use was associated with improved recurrence-free survival (HR = 0.87; 95% CI: 0.78,0.97; n = 23; I = 64%), but not with improvement in progression-free survival (HR = 1.05; 95% CI: 0.95,1.16; n = 14; I2 = 38%).The meta-analysis demonstrated that statin use could exhibit potential survival benefit in the prognosis of cancer patients. But our results are conservative for statins to improve disease recurrence and progression. These findings should be assessed in a prospective randomized cohort.

Individual and joint effects of metformin and statins on mortality among patients with high-risk prostate cancer

BACKGROUND

Pre-clinical studies suggest that metformin and statins may delay prostate cancer (PCa) metastases; however, data in humans are limited. To the best of our knowledge, this is the first human study aimed to quantify the individual and joint effects of statin and metformin use among patients with high-risk PCa.

METHODS

This population-based retrospective cohort study identified patients from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. Exposure to metformin and statins was ascertained from Medicare Prescription Drug Event files. The association with all-cause and PCa mortality were evaluated using Cox proportional hazard model with competing causes of death, where propensity scores were used to adjusted imbalances in covariates across groups.

RESULTS

Based on 12 700 patients with high-risk PCa, statin alone or in combination with metformin was significantly associated with reduced all-cause mortality (Hazard Ratio [HR]: 0.89; 95% Confidence Interval [CI]: 0.83, 0.96; and HR: 0.75; 95% CI, 0.67-0.83, respectively) and PCa mortality (HR, 0.80; 95% CI: 0.69, 0.92) and 0.64; 95% CI, d 0.51-0.81, respectively. The effects were more pronounced in post-diagnostic users: combination use of metformin/statins was associated with a 32% reduction in all-cause mortality (95% CI, 0.57-0.80), and 54% reduction in PCa mortality (95% CI, 0.30-0.69). No significant association of metformin alone was observed with either all-cause mortality or PCa mortality.

CONCLUSIONS

Statin use alone or in combination with metformin was associated with lower all-cause and PCa mortality among high-risk patients, particularly in post-diagnostic settings; further studies are warranted.

Impact of Metabolic Diseases, Drugs, and Dietary Factors on Prostate Cancer Risk, Recurrence, and Survival: A Systematic Review by the European Association of Urology Section of Oncological Urology

CONTEXT

To date, established risk factors for prostate cancer (PCa) are limited to age, race, family history, and certain genetic polymorphisms. Despite great research efforts, available evidence on potentially modifiable risk factors is conflicting. Moreover, most studies on PCa risk factors did not consider the impact of prostate-specific antigen (PSA) testing on PCa diagnosis.

OBJECTIVE

To provide a detailed overview of the latest evidence on the role of metabolic diseases, drugs, and dietary factors for risk of PCa incidence, recurrence, and survival in men exposed to PSA testing.

EVIDENCE ACQUISITION

A systematic review of the English-language literature was performed using the MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses recommendations. Randomized, case-control, or cohort studies published during the periods 2008-2017 (on drugs and metabolic diseases) and 2003-2017 (on dietary factors), with extensive follow-up (≥8-10yr for studies on PCa risk; ≥2-5yr for studies on PCa recurrence, progression, and survival, depending on the review subtopic) and adjusting of the analyses, beyond established risk factors, for either rate of PSA testing (for risk analyses) or PCa stage and primary treatment (for survival analyses), were eligible for inclusion.

EVIDENCE SYNTHESIS

Overall, 39 reports from 22 observational studies were included. Studies were heterogeneous regarding definitions of exposure or outcomes, length of follow-up, risk of bias, and confounding. For some risk factors, evidence was insufficient to assess potential effects, while for others there was no evidence of an effect. For selected risk factors, namely metformin, aspirin and statin use, diabetes, obesity, and specific dietary intakes, there was low-quality evidence of modest effects on PCa risk.

CONCLUSIONS

Current evidence from long-term observational studies evaluating the effect of drugs, metabolic diseases, and dietary factors for PCa risk considering the impact of PSA testing is still not conclusive. Future research is needed to confirm the associations suggested by our review, exploring their potential biological explanations and selecting those risk factors most likely to trigger effective public health interventions.

PATIENT SUMMARY

We reviewed the available studies published in the recent literature on the potential role of drugs, metabolic diseases, and food and dietary factors for the risk of prostate cancer, considering the impact of prostate-specific antigen testing on prostate cancer diagnosis. We found that for some factors data are currently insufficient to make definitive conclusions, while for others available studies seem to indicate an effect on the risk of prostate cancer.

Access and concentrations of atorvastatin in the prostate in men with prostate cancer

BACKGROUND

Statins have anticancer effects on prostate cancer both in vitro and in vivo. It is unclear whether this is due to systemic cholesterol-lowering or direct local growth inhibition in the prostate. It is also unclear whether statins can access the prostate; lipophilic statins could, in theory, pass lipid-enriched cell membranes by passive diffusion. However, statin concentrations in the human prostate have not been measured before.

METHODS

The study population was based on a randomized clinical trial where 158 men with prostate cancer were randomized to use 80 mg atorvastatin (ATV) or placebo daily for a median of 27 days before radical prostatectomy. ATV and atorvastatin lactone (ATV-Lactone) concentrations in the plasma and in the prostate were measured with mass spectrometry in men randomized to the ATV arm. Linear trends between intraprostatic concentration and plasma concentration, body mass index, age, and duration of intervention were examined. The relative tissue concentrations of ATV and ATV-Lactone were calculated in prostatic tissue and plasma to evaluate drug homeostasis. Subgroup analyses were stratified by tumor and population characteristics.

RESULTS

The analysis involved a total of 55 men. When limited to men whose tissue concentrations of ATV was measurable (n = 28, 50%), median ATV concentration was 212% higher in the tissue (median concentration 17.6 ng/g) compared to the plasma (median concentration 3.6 ng/mL). Also, ATV-L concentration was 590% higher in the tissue as compared to the plasma concentration. No statistically significant linear trends between the plasma and tissue concentrations were observed. When comparing the relative concentration of atorvastatin lactone over ATV, the concentrations were in balance in the plasma, In the prostate, however, the relative concentration of atorvastatin lactone was 57% lower compared to ATV (P = .009 for the difference between prostate tissue and plasma). No effect modification by tumor or population characteristics was observed.

CONCLUSIONS

Measurable ATV concentrations in the prostate support ATV's ability to access the prostate from the circulation. ATV may accumulate in the prostate as intraprostatic concentrations are elevated compared to the plasma concentration.

Prostate cancer survival among statin users after prostatectomy in a Finnish nationwide cohort

BACKGROUND

Improved prostate cancer (PCa) survival by statin use has been reported among PCa patients managed with radiation or androgen deprivation therapy (ADT), while results are controversial for men managed surgically. We evaluate the association between cholesterol-lowering medication with initiation of ADT and disease-specific death among PCa cases who underwent radical prostatectomy in Finland between 1995 and 2013.

METHODS

The study cohort included 14 424 men with PCa who underwent radical prostatectomy in Finland between 1995 and 2013. Cases were identified from national hospital discharge registry. Clinical data were amended from patient files of the treating hospitals. Information on co-morbidities, additional radiation- or chemotherapy, and causes of deaths were collected from national registries. Personal-level data on medication use during 1995-2014 were gathered from national prescription database. Registry linkages were carried out using personal identification number. Lipid-lowering drugs were categorized into statins and non-statin drugs. Risk of PCa death and initiation of ADT was analyzed using Cox-regression model with adjustment for age, radiation therapy, chemotherapy, co-morbidities and other drug use. Statin use was analyzed as time-dependent variable. Delayed risk associations were evaluated in lag-time analysis.

RESULTS

Compared to non-users the risk of PCa death was significantly lower among statin users before PCa diagnosis (HR 0.70, 95%CIs 0.52-0.95). For statin use after PCa diagnosis the risk was lowered in age-adjusted analysis (HR 0.76 95%CIs 0.62-0.93) but not after multivariable-adjustment. Post-diagnostic statin use was associated with improved PCa-specific survival in 1, 3 and 5 years lag-time analyses. The risk reduction was clearest for statin use initiated 5 years earlier (HR 0.71 95%CIs 0.55-0.92). Use of statins both before and after PCa diagnosis was associated with reduced risk of ADT use (HR 0.72 95%CIs 0.65-0.80 and HR 0.73, 95%CI 0.67-0.80, respectively). The risk of ADT decreased by increasing intensity of statin use before diagnosis.

CONCLUSION

Statin use among surgically treated PCa patients has significant association with decreased risk of starting ADT and PCa death. The risk is lowered especially among men with statin use before PCa diagnosis and in men who used statins at high-dose. Our results are hypothesis generating due to retrospective study design.

Mortality associated with statins in men with advanced prostate cancer treated with androgen deprivation therapy

OBJECTIVES

Before launching large clinical trials to confirm the effects of statins in improving outcomes among men with prostate cancer (PC), the most appropriate target patient population and the type of statins need to be clearly identified.

PATIENTS AND METHODS

A retrospective cohort study was conducted using the Taiwan Cancer Registry of 2008-2014. This study included 5749 men with locally advanced and metastatic PC who received only androgen deprivation therapy (ADT) in the first year after their cancer diagnosis. Statin users were defined as anyone who was prescribed statins for >28 days. An inverse probability of treatment-weighted Cox model was used to estimate the effects of statin use on all-cause mortality and PC-specific mortality (PCSM) while treating the statin status as a time-dependent variable.

RESULTS

Overall, 2259 patients died, and 1495 of them died of PC during a median follow-up of 3.6 years from 1 year after their diagnosis. Statin use was associated with significant reductions in all-cause mortality (hazard ratio [HR] = 0.78, 95% confidence interval [CI]: 0.70-0.86) and PCSM (HR = 0.76, 95% CI: 0.68-0.86) for metastatic disease and all-cause mortality (HR = 0.66, 95% CI: 0.54-0.81) for locally advanced disease. Patients who received atorvastatin, pravastatin, rosuvastatin or pitavastatin showed a stronger reduction in mortality than those who received other statins. Benefits of statins were consistently observed in men who received post-diagnostic statins, even in those with high comorbidities or an old age.

CONCLUSIONS

Our results suggest that only atorvastatin, pravastatin and rosuvastatin were associated with improved survival in advanced PC patients receiving ADT.

Serum cholesterol and prostate cancer risk in the Finnish randomized study of screening for prostate cancer

BACKGROUND

Hypercholesterolemia has been associated with advanced stage prostate cancer (PCa), but the role of lipid parameters such as HDL and triglycerides is unclear. We examined PCa risk by lipid parameters in a population nested within the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC).

METHODS

Cholesterol measurements were available on 17,696 men. During the 17-year median follow-up, 2404 PCa cases were diagnosed. Cox regression model was used to estimate hazard ratios (HR) and their 95% confidence intervals (95% CI) for overall PCa risk and stratified by Gleason grade and tumor stage. We compared normolipidemic and hyperlipidemic men on four cholesterol parameters total cholesterol (TC), HDL, LDL, and triglycerides (TG), analyzed as time-dependent variables.

RESULTS

TC in the highest tertile (above 5.1 mmol/l) and LDL above 3 mmol/l were associated with increased risk of Gleason 8-10 cancer (HR 1.42, 95% CI 1.04-1.95 and HR 1.38, 95% CI 1.02-1.86, respectively). Further, overall PCa risk was elevated in the 3-year lag time analysis by TC in the highest two tertiles (HR 1.27, 95% CI 1.05-1.54 for TC above 4.4 mmol/l, and HR 1.26, 95% CI 1.05-1.51 for TC above 5.1 mmol/l) and HDL in the highest tertile (HR 1.33, 95% CI 1.08-1.64) and above 1 mmol/l (HR 1.29, 95% CI 1.01-1.65). In contrast, TC in the highest tertile was associated with a decreased risk of PCa with 20-year lag time. The risk associations for overall PCa grew stronger with added lag time but were observed only in the FinRSPC control arm. Statin use did not modify the risk association.

CONCLUSIONS

Hypercholesterolemia may increase overall PCa risk in short-term, inverse risk association was observed with 20-years' time lag. Similar risk increase of overall PCa was also observed for elevated HDL, conflicting with previous findings on the subject.

Association between post-diagnostic use of cholera vaccine and risk of death in prostate cancer patients

Recent evidence suggests that cholera toxin might have multiple functions regarding the ability to regulate the immune system. However, it is unknown whether subsequent administration of cholera vaccine might affect the mortality rate in patients with prostate cancer. Here we report that patients in Sweden, who were diagnosed with prostate cancer between July 2005 and December 2014 and used cholera vaccine, have a decreased risk of death from prostate cancer (HR, 0.57; 95% CI, 0.40-0.82) as compared to patients with prostate cancer but without cholera vaccine use, adjusted for a range of confounding factors. In addition, patients using cholera vaccine show a decreased risk of death overall (HR, 0.53; 95% CI, 0.41-0.69). The decreased mortality rate is largely consistent, irrespective of patients' age or tumor stage at diagnosis. In this population-based study, we suggest that subsequent administration of cholera vaccine after prostate cancer diagnosis might reduce the mortality rate.

Lipid pathway deregulation in advanced prostate cancer

The link between prostate cancer (PC) development and lipid metabolism is well established, with AR intimately involved in a number of lipogenic processes involving SREBP1, PPARG, FASN, ACC, ACLY and SCD1. Recently, there is growing evidence implicating the role of obesity and peri-prostatic adipose tissue (PPAT) in PC aggressiveness and related mortality, suggesting the importance of lipid pathways in both localised and disseminated disease. A number of promising agents are in development to target the lipogenic axis in PC, and the likelihood is that these agents will form part of combination drug strategies, with targeting of multiple metabolic pathways (e.g. FASN and CPT1), or in combination with AR pathway inhibitors (SCD1 and AR).