Statin Use and Risk of Prostate Cancer Recurrence in Men Treated With Radiation Therapy

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.

Ferroptosis: Frenemy of Radiotherapy

Recently, it was established that ferroptosis, a type of iron-dependent regulated cell death, plays a prominent role in radiotherapy-triggered cell death. Accordingly, ferroptosis inducers attracted a lot of interest as potential radio-synergizing drugs, ultimately enhancing radioresponses and patient outcomes. Nevertheless, the tumor microenvironment seems to have a major impact on ferroptosis induction. The influence of hypoxic conditions is an area of interest, as it remains the principal hurdle in the field of radiotherapy. In this review, we focus on the implications of hypoxic conditions on ferroptosis, contemplating the plausibility of using ferroptosis inducers as clinical radiosensitizers. Furthermore, we dive into the prospects of drug repurposing in the domain of ferroptosis inducers and radiosensitizers. Lastly, the potential adverse effects of ferroptosis inducers on normal tissue were discussed in detail. This review will provide an important framework for subsequent ferroptosis research, ascertaining the feasibility of ferroptosis inducers as clinical radiosensitizers.

Modulation of radiosensitivity of DU145 prostate carcinoma cells by simvastatin

PURPOSE

To investigate antiproliferative effects of simvastatin in combination with ionizing radiation on DU145 prostate cancer cells and its influence on cellular HMG-CoA-reductase levels.

METHODS

Proliferative responses of DU145 cells were estimated by means of a clonogenic assay or the crystal violet procedure. HMG-CoA-reductase levels were measured by western blot analysis.

RESULTS

The antiproliferative effects of simvastatin and radiation are dependent on simvastatin dose, radiation dose and treatment time. In vitro treatment of DU145 cells with simvastatin induced HMG-CoA-reductase levels.

CONCLUSION

Ionizing radiation more profoundly reduces proliferation as compared to simvastatin exposure, while the combined application of both modalities is synergistic. The inhibition of CoA-reductase may contribute to these effects.

Targeting lipid metabolism in metastatic prostate cancer

Despite key advances in the treatment of prostate cancer (PCa), a proportion of men have de novo resistance, and all will develop resistance to current therapeutics over time. Aberrant lipid metabolism has long been associated with prostate carcinogenesis and progression, but more recently there has been an explosion of preclinical and clinical data which is informing new clinical trials. This review explores the epidemiological links between obesity and metabolic syndrome and PCa, the evidence for altered circulating lipids in PCa and their potential role as biomarkers, as well as novel therapeutic strategies for targeting lipids in men with PCa, including therapies widely used in cardiovascular disease such as statins, metformin and lifestyle modification, as well as novel targeted agents such as sphingosine kinase inhibitors, DES1 inhibitors and agents targeting FASN and beta oxidation.

Serum Paraoxonase-1 Activity in Prostate Cancer Patients Treated with Brachytherapy as a Measure of Irradiation Efficacy

We investigated changes in the activity of antioxidant paraoxonase-1 (PON1) in patients with prostate cancer (PCa) undergoing radiotherapy (RT), as well as the relationship of the PON1 activity with the degree of PCa advancement. We included 84 men with PCa. Blood samples were obtained before irradiation and after the completion of RT. The control group was composed of 60 healthy men. There was no significant difference in the PON1 activity between the control group and patients pre-radiotherapy. Irradiation was associated with a significant decrease in the PON1 activity; thus, it could be a measure of the efficacy of RT. No significant correlations between the PON1 activity and Gleason score, prostate volume, BMI (body mass index), or adipose tissue thickness were found. However, there was a positive correlation between the PON1 activity and the PSA concentration in the group of PCa patients.

Association of Statin Use with the Risk of Incident Prostate Cancer: A Meta-Analysis and Systematic Review

Background

With the growth and aging of population, the incidence of prostate cancer will increase year by year, which is bound to bring greater economic burden to the society. There has been greater interest in the anticancer effects of statin in recent years. It is controversial whether statin use is associated with the risk of prostate cancer (PCa). Thus, we conducted a meta-analysis and systematic review to explore the effects of statin use and their duration and cumulative dose on the overall incidence of PCa.

Method

The study was conducted according to the latest guidelines for PRISMA 2020. We searched PubMed and other databases for studies about the association of statin use with the risk of incident prostate cancer between January 1, 1990, and April 11, 2022. Two independent researchers extracted data and evaluated the quality of the studies. R x64 4.1.2 and random-effects model were used for data statistics. Relative risk (RR) and odds ratio (OR) effective values with a 95% confidence interval (95% CI) were used to assess the main results.

Results

The results of 6 RCT and 26 cohort studies showed that statins did not significantly associate with the incidence of PCa (RR = 0.94, 95% CI: 0.82-1.08). The similar results were obtained from 9 case-control studies (OR = 1.03, 95% CI: 0.99-1.07). However, statins were associated with a lower risk of Pca (RR = 0.44, 95% CI: 0.28-0.70) when the cumulative defined daily dose (cDDD) was high. Using statins for more than five years could be associated with a reduced incidence of Pca (RR = 0.47, 95% CI: 0.23-0.97). There was a significant heterogeneity in these studies (RCT and cohort study: I ² = 98%, P < 0.01; case-control study: I ² = 72%, P < 0.01).

Conclusion

We concluded that statins had a neutral association with the overall risk of PCa. High cDDD and long duration were associated with a lower risk of PCa.

Advances and development of prostate cancer, treatment, and strategies: A systemic review

The most common type of cancer in the present-day world affecting modern-day men after lung cancer is prostate cancer. Prostate cancer remains on the list of top three cancer types claiming the highest number of male lives. An estimated 1.4 million new cases were reported worldwide in 2020. The incidence of prostate cancer is found predominantly in the regions having a high human development index. Despite the fact that considerable success has been achieved in the treatment and management of prostate cancer, it remains a challenge for scientists and clinicians to curve the speedy advancement of the said cancer type. The most common risk factor of prostate cancer is age; men tend to become more vulnerable to prostate cancer as they grow older. Commonly men in the age group of 66 years and above are the most vulnerable population to develop prostate cancer. The gulf countries are not far behind when it came to accounting for the number of individuals falling prey to the deadly cancer type in recent times. There has been a consistent increase in the incidence of prostate cancer in the gulf countries in the past decade. The present review aims at discussing the development, diagnostics via machine learning, and implementation of treatment of prostate cancer with a special focus on nanotherapeutics, in the gulf countries.

Impact of Statin Use on Localized Prostate Cancer Outcomes after Radiation Therapy: Long-Term Follow-Up

Simple Summary

Statins represent a promising class of agents to improve clinical outcomes of prostate cancer patients treated with radiotherapy, but the results of numerous studies are contradictory. We aimed to assess the impact of statin use on biochemical recurrence in a large database of patients of different risk groups undergoing different modalities of radiation therapy. We evaluated 3555 patients treated with curative external beam radiotherapy, low-dose-rate seed brachytherapy, or external beam radiotherapy plus high-dose-rate brachytherapy. We found no improvement in biochemical recurrence-free survival in statin users, regardless of radiotherapy modality. Our study underlines the need to search for biomarkers that predict an additive effect of statins and determine which patients treated with radiotherapy may benefit from statins as an anticancer drug.

Abstract

The impact of statin use on localized prostate cancer (PCa) remains controversial, especially for patients treated with radiation therapy. We assessed the impact of statin use on biochemical recurrence (BCR) in patients treated for PCa with different modalities of radiation therapy. We evaluated 3555 patients undergoing radiation therapy between January 2001 and January 2022. The impact of statin use on BCR was analyzed for three treatment groups: external beam radiotherapy (EBRT), low-dose-rate seed brachytherapy (LDR), and EBRT plus high-dose-rate brachytherapy (EBRT + HDR). Median follow-up was 52 months among 1208 patients treated with EBRT, 1679 patients treated with LDR, and 599 patients treated with EBRT + HDR. A total of 1544 (43%) patients were taking a statin at the time of treatment, and 497 (14%) patients were in the D’Amico high-risk group. Only intermediate-risk patients treated with LDR fared better with statin use in univariate analysis (p = 0.025). This association was not significant in multivariate analysis (HR 0.44, 95% CI 0.18–1.10, p = 0.06). Statin use was not associated with a reduced risk of BCR in patients treated with radiation therapy. In the era of precision medicine, further investigation is needed to assess the benefit of statins in well-defined patients.

Statin Use and the Risk of Prostate Cancer Biochemical Recurrence Following Definitive Therapy: A Systematic Review and Meta-Analysis of Cohort Studies

Background

Numerous studies have reported the role of statins on biochemical recurrence (BCR) among patients with prostate cancer (PCa) after definite treatment. However, the conclusions of these studies are contradictory. We aimed to determine the effect of statins on BCR of PCa using a systematic review and meta-analysis.

Methods

We searched PubMed (Medline) and other databases for cohort studies evaluating the effect of statins on the BCR of patients with PCa between January 1, 2000, and December 31, 2021. The random effects (RE) model and quality effects (QE) model were used to calculate the pooled hazard ratio (pHR) and pooled risk ratio (pRR) and their 95% confidence interval (95% CI).

Results

A total of 33 cohort studies were finally selected and included in this systematic review and meta-analysis. Statin use was significantly associated with a 14% reduction in the HR of BCR (pHR: 0.86, 95% CI: 0.78 to 0.95, I² = 64%, random effects model, 31 studies) and a 26% reduction in the RR of BCR (pRR: 0.74, 95% CI: 0.57 to 0.94, 24,591 patients, I² = 88%, random effects model, 15 studies) among patients with PCa. The subgroup analyses showed that statins could result in 22% reduction in the HR of BCR (pHR: 0.78, 95% CI: 0.61 to 0.98, I² = 57%, random effects model) among patients accepting radiotherapy (RT).

Conclusions

Our study suggests that statins have a unique role in the reduction of BCR in patients with PCa after definite treatment, especially RT. In the future, more clinical trials and in vitro and animal experiments are needed to further verify the effects of statins in PCa and the potential mechanisms.

Formulation of simvastatin within high density lipoprotein enables potent tumour radiosensitisation

Preclinical, clinical and epidemiologic studies have established the potent anticancer and radiosensitisation effects of HMG-CoA reductase inhibitors (statins). However, the low bioavailability of oral statin formulations is a key barrier to achieving effective doses within tumour. To address this issue and ascertain the radiosensitisation potential of simvastatin, we developed a parenteral high density lipoprotein nanoparticle (HDL NP) formulation of this commonly used statin. A scalable method for the preparation of the simvastatin-HDL NPs was developed using a 3D printed microfluidic mixer. This enables the production of litre scale amounts of particles with minimal batch to batch variation. Simvastatin-HDL NPs enhanced the radiobiological response in 2D/3D head and neck squamous cell carcinoma (HNSCC) in vitro models. The simvastatin-HDL NPs radiosensitisation was comparable to that of 10 and 5 times higher doses of free drug in 2D and 3D cultures, respectively, which could be partially explained by more efficient cellular uptake of the statin in the nanoformulation as well as by the inherent biological activity of the HDL NPs on the cholesterol pathway. The radiosensitising potency of the simvastatin-HDL nanoformulation was validated in an immunocompetent MOC-1 HNSCC tumour bearing mouse model. This data supports the rationale of repurposing statins through reformulation within HDL NPs. Statins are safe and readily available molecules including as generic, and their use as radiosensitisers could lead to much needed effective and affordable approaches to improve treatment of solid tumours.

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

Growing evidence suggests that men prescribed a statin for cholesterol control have a lower risk of advanced prostate cancer (PCa) and improved treatment outcomes; however, the mechanism by which statins elicit their anti-neoplastic effects is not well understood and is likely multifaceted. Statins are potent and specific inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), the rate-limiting enzyme of the mevalonate (MVA) metabolic pathway. This two-part series is a review of the observational and experimental data on statins as anti-cancer agents in PCa. In this article, we describe the functional role that deregulated MVA metabolism plays in PCa progression and summarize the biological evidence and rationale for targeting the MVA pathway, with statins and other agents, for the treatment of PCa.

Combination therapy with novel androgen receptor antagonists and statin for castration-resistant prostate cancer

BACKGROUND

One of the growth mechanisms of castration-resistant prostate cancer (CRPC) is de novo androgen synthesis from intracellular cholesterol, and statins may be able to inhibit this mechanism. In addition, statins have been reported to suppress the expression of androgen receptors (ARs) in prostate cancer cell lines. In this study, we investigated a combination therapy of novel AR antagonists and statin, simvastatin, for CRPC.

METHODS

LNCaP, 22Rv1, and PC-3 human prostate cancer cell lines were used. We developed androgen-independent LNCaP cells (LNCaP-LA). Microarray analysis was performed, followed by pathway analysis, and mRNA and protein expression was evaluated by quantitative real-time polymerase chain reaction and Western blot analysis, respectively. Cell viability was determined by MTS assay and cell counts. All evaluations were performed on cells treated with simvastatin and with or without AR antagonists (enzalutamide, apalutamide, and darolutamide).

RESULTS

The combination of darolutamide and simvastatin most significantly suppressed proliferation in LNCaP-LA and 22Rv1 cells. In a 22Rv1-derived mouse xenograft model, the combination of darolutamide and simvastatin enhanced the inhibition of cell proliferation. In LNCaP-LA cells, the combination of darolutamide and simvastatin led to reduction in the mRNA expression of the androgen-stimulated genes, KLK2 and PSA; however, this reduction in expression did not occur in 22Rv1 cells. The microarray data and pathway analyses showed that the number of differentially expressed genes in the darolutamide and simvastatin-treated 22Rv1 cells was the highest in the pathway termed "role of cell cycle." Consequently, we focused our efforts on the cell cycle regulator polo-like kinase 1 (PLK1), cyclin-dependent kinase 2 (CDK2), and cell cycle division 25C (CDC25C). In 22Rv1 cells, the combination of darolutamide and simvastatin suppressed the mRNA and protein expression of these three genes. In addition, in PC-3 cells (which lack AR expression), the combination of simvastatin and darolutamide enhanced the suppression of cell proliferation and expression of these genes.

CONCLUSIONS

Simvastatin alters the expression of many genes involved in the cell cycle in CRPC cells. Thus, the combination of novel AR antagonists (darolutamide) and simvastatin can potentially affect CRPC growth through both androgen-dependent and androgen-independent mechanisms.

The association of statin use and biochemical recurrence after curative treatment for prostate cancer: A systematic review and meta-analysis

OBJECTIVES

: To investigate the association between statin use and biochemical recurrence (BCR) in patients undergoing radical prostatectomy (RP) or radiotherapy (RT) as a curative treatment, a systematic review and meta-analysis was performed.

METHODS

: We conducted a literature search of online databases for studies assessing BCR associated with statin use in patients with prostate cancer undergoing RP or RT. We performed a pooled analysis of BCR-free survival with subgroup analysis of treatment, cancer risk, and medication.

RESULTS

: We identified 27 studies and found that statin use was associated with a potential tendency to improve BCR-free survival in patients undergoing curative treatment (P = .05). In addition, we revealed that statin use after curative treatment did not improve BCR-free survival (P = .33), whereas statin use could improve BCR-free survival in high-risk patients (P < .01).

CONCLUSIONS

: Statin use is associated with a potential tendency to improve BCR-free survival in prostate cancer and could reduce BCR in high-risk patients.

Prostate Cancer-Focus on Cholesterol

Prostate cancer (PC) is the most common malignancy in men. Common characteristic involved in PC pathogenesis are disturbed lipid metabolism and abnormal cholesterol accumulation. Cholesterol can be further utilized for membrane or hormone synthesis while cholesterol biosynthesis intermediates are important for oncogene membrane anchoring, nucleotide synthesis and mitochondrial electron transport. Since cholesterol and its biosynthesis intermediates influence numerous cellular processes, in this review we have described cholesterol homeostasis in a normal cell. Additionally, we have illustrated how commonly deregulated signaling pathways in PC (PI3K/AKT/MTOR, MAPK, AR and p53) are linked with cholesterol homeostasis regulation.

Atorvastatin induces adrenal androgen downshift in men with prostate cancer: A post Hoc analysis of a pilot adaptive Randomised clinical trial

BACKGROUND

Prostate cancer (PCa) progression depends on androgen receptor activity. Cholesterol is required for biosynthesis of all steroid hormones, including androgens. Impact of cholesterol-lowering statins on androgens is unknown. We explored atorvastatin influence on serum and prostatic tissue steroidomic profiles (SP) to expose novel pathways for limiting androgen concentration in men with PCa.

METHODS

This is a pre-planned post hoc analysis of ESTO-1 pilot randomised, double-blinded, clinical trial. Statin naïve men, scheduled for radical prostatectomy due to localised PCa, were randomised 1:1 to use daily 80 mg of atorvastatin or placebo before the surgery for a median of 28 days. Participants were recruited and treated at the Pirkanmaa Hospital District, Tampere, Finland. 108 of the 158 recruited men were included in the analysis based on sample availability for hormone profiling. Serum and prostatic tissue steroid profiles were determined using liquid chromatography mass spectrometry. Wilcoxon rank sum test and bootstrap confidence intervals (CI) were used to analyse the difference between placebo and atorvastatin arms.

FINDINGS

Most serum and prostatic steroids, including testosterone and dihydrotestosterone, were not associated with atorvastatin use. However, atorvastatin use induced serum SP changes in 11-ketoandrostenedione (placebo 960pM, atorvastatin 617.5pM, p-value <0.0001, median difference -342.5; 95% CI -505.23 - -188.98). In the prostatic tissue, atorvastatin was associated with plausible downshift in 11- ketodihydrotestosterone (placebo 25.0pM in 100 mg tissue/1 mL saline, atorvastatin 18.5pM in 100 mg tissue/1 mL saline, p-value 0.027, median difference -6.53; 95% CI -12.8 - -0.29); however, this association diminished after adjusting for multiple testing. No serious harms were reported.

INTERPRETATION

Atorvastatin was associated with adrenal androgen downshift in the serum and possibly in the prostate. The finding warrants further investigation whether atorvastatin could improve androgen deprivation therapy efficacy.

FUNDING

Funded by grants from the Finnish Cultural Foundation, Finnish Cancer Society, Academy of Finland, and the Expert Responsibility Area of the Tampere University Hospital. CLINICALTRIALS.

GOV IDENTIFIER

NCT01821404.

A prospective clinical and transcriptomic feasibility study of oral-only hormonal therapy with radiation for unfavorable prostate cancer in men 70 years of age and older or with comorbidity

BACKGROUND

Androgen deprivation therapy (ADT) improves outcomes in unfavorable-risk prostate cancer (PCa) treated with radiation therapy (RT). It was hypothesized that replacing luteinizing hormone-releasing hormone (LHRH) agonists with a 5-α-reductase inhibitor (5-ARI) would improve hormonal health-related quality of life (HRQOL) without differentially suppressing androgen-responsive (AR) gene expression.

METHODS

Patients with localized unfavorable-risk PCa, aged ≥70 years or Charlson Comorbidity Index score ≥2 were treated with oral ADT (oADT), consisting of 4 months of bicalutamide, a 5-ARI, and RT at 78 Gy. The primary end point was Expanded Prostate Cancer Index Composite HRQOL at 6 months ≤30%, and improvement compared with a synchronous standard of care (SOC) cohort receiving 4 months of bicalutamide and long-term LHRH agonist with RT. RNA sequencing was performed from matched pre-/post-ADT prostate tumor biopsies in a subset of men. Differential gene and pathway expressional changes were examined using gene set enrichment.

RESULTS

Between 2011 and 2018, 40 and 30 men were enrolled in the oADT and SOC cohorts, respectively. Median follow-up was 40 months. Those with ≤30% decline in hormonal HRQOL at 6 months was 97% (oADT) and 93% (SOC). The average 6-month hormonal decline was 1% (oADT) versus 12% (SOC; P = .04). The 4-year freedom from biochemical failure was 88% (oADT) versus 81% (SOC; P = .48). RNA sequencing (n = 9) showed similar numbers of downregulated and upregulated genes between the treatment groups (fold-change = 2; false-discovery rate-adjusted P ≤ .05). Both treatments comparably decreased the expression of 20 genes in canonical androgen receptor signaling.

CONCLUSIONS

For men with PCa undergoing RT, oral versus standard ADT may improve 6-month QOL and appears to have a similar impact on androgen-responsive gene expression.

Impact of statin use on overall and time to biochemical failure following radical prostatectomy or radiation therapy

OBJECTIVES

To assess the impact of statin use on overall and time to biochemical failure following primary treatment of localized prostate cancer (PCa).

SUBJECTS/PATIENTS AND METHODS

1581 patients undergoing radical prostatectomy (RP) or radiation therapy (RT) for primary treatment of PCa between July 2007 and January 2020 were evaluated for statin use, demographic/oncologic characteristics, and biochemical outcomes. Rate of biochemical failure (BF) was assessed overall and at 1, 3, and 5 years; time to BF was estimated with Kaplan-Meier. Logistic and linear regression were used to control for treatment modality and disease characteristics.

RESULTS

The average age was 63.0 ± 7.5 years and median pre-treatment PSA was 6.55 (IQR 4.94). 1473 (93.2%) and 108 (6.8%) underwent RP and RT, respectively. RP patients were younger, had lower pre-PSA, lower BMI, and lower risk disease. At 3.4 ± 2.7 years follow-up, 323 (20.4%) experienced BF. When stratified by statin use, BF overall and within 1, 3, and 5 years were not different. Time to BF, was lower in patients using statins (1.8 ± 1.9 years vs. 2.4 ± 2.6 years; p = 0.016). These results persisted in multivariate analysis, wherein statin use was not associated with BF but was associated with a shorter time to BF.

CONCLUSION

Overall, statin use was not associated with a reduced risk of BF in RP or RT patients. However, for patients with BF, statin use was associated with a decreased time to BF. Future investigations are warranted to further elucidate the impact of statin use on PCa recurrence.

Systemic Inflammatory Markers Are Predictive of the Response to Brachytherapy in the Prostate

We analyzed the influence of the neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) on the biochemical recurrence (BCR) in low-intermediate risk prostate cancer (PCa). A total of 604 patients treated with exclusive brachytherapy for low- and intermediate-risk cancers were included in this study. No patient received either androgen deprivation or brachytherapy as a boost. BCR was defined according to the Phoenix definition (nadir prostatic specific antigen (PSA) +2). The median follow-up was 60 months (IQR 44–48 months). An NLR > 3 was more frequent in statin users (p = 0.025), but not in diabetics (p = 0.079). In univariate analysis (UVA) and multivariate analysis (MVA), a NLR > 3 (MVA p = 0.03), as well as Cancer of the Prostate Risk Assessment (CAPRA) low- vs. intermediate-risk (MVA p = 0.04), were predictive of BCR. When combining the NLR score with the CAPRA risk group, CAPRA intermediate risk patients with an NLR ≤ 3 (n = 157) had the worst (p = 0.0276) BCR rates, with a 5-year recurrence-free survival (p = 0.004, Bonferroni correction for six comparisons p = 0.024). We were able to identify a subgroup of PCa patients with CAPRA intermediate-risk and an NLR ≤ 3 who had worse BCR. This is in contrast to most other cancers, which have a worse prognosis when the NLR is high.

Prostate cancer management: long-term beliefs, epidemic developments in the early twenty-first century and 3PM dimensional solutions

In the early twenty-first century, societies around the world are facing the paradoxal epidemic development of PCa as a non-communicable disease. PCa is the most frequently diagnosed cancer for men in several countries such as the USA. Permanently improving diagnostics and treatments in the PCa management causes an impressive divergence between, on one hand, permanently increasing numbers of diagnosed PCa cases and, on the other hand, stable or even slightly decreasing mortality rates. Still, aspects listed below are waiting for innovate solutions in the context of predictive approaches, targeted prevention and personalisation of medical care (PPPM / 3PM).A.PCa belongs to the cancer types with the highest incidence worldwide. Corresponding economic burden is enormous. Moreover, the costs of treating PCa are currently increasing more quickly than those of any other cancer. Implementing individualised patient profiles and adapted treatment algorithms would make currently too heterogeneous landscape of PCa treatment costs more transparent providing clear "road map" for the cost saving.B.PCa is a systemic multi-factorial disease. Consequently, predictive diagnostics by liquid biopsy analysis is instrumental for the disease prediction, targeted prevention and curative treatments at early stages.C.The incidence of metastasising PCa is rapidly increasing particularly in younger populations. Exemplified by trends observed in the USA, prognosis is that the annual burden will increase by over 40% in 2025. To this end, one of the evident deficits is the reactive character of medical services currently provided to populations. Innovative screening programmes might be useful to identify persons in suboptimal health conditions before the clinical onset of metastasising PCa. Strong predisposition to systemic hypoxic conditions and ischemic lesions (e.g. characteristic for individuals with Flammer syndrome phenotype) and low-grade inflammation might be indicative for specific phenotyping and genotyping in metastasising PCa screening and disease management. Predictive liquid biopsy tests for CTC enumeration and their molecular characterisation are considered to be useful for secondary prevention of metastatic disease in PCa patients.D.Particular rapidly increasing PCa incidence rates are characteristic for adolescents and young adults aged 15-40 years. Patients with early onset prostate cancer pose unique challenges; multi-factorial risks for these trends are proposed. Consequently, multi-level diagnostics including phenotyping and multi-omics are considered to be the most appropriate tool for the risk assessment, prediction and prognosis. Accumulating evidence suggests that early onset prostate cancer is a distinct phenotype from both aetiological and clinical perspectives deserving particular attention from view point of 3P medical approaches.

Repurposing Drugs for Cancer Radiotherapy: Early Successes and Emerging Opportunities

It has long been recognized that combining radiotherapy with cytotoxic drugs such as cisplatin can improve efficacy. However, while concurrent chemoradiotherapy improves patient outcomes, it comes at costs of increased toxicity. A tremendous opportunity remains to investigate drug combinations in the clinical setting that might increase the benefits of radiation without additional toxicity. This chapter highlights opportunities to apply repurposing of drugs along with a mechanistic understanding of radiation effects on cancer and normal tissue to discover new therapy-modifying drugs and help rapidly translate them to the clinic. We survey candidate radiosensitizers that alter DNA repair, decrease hypoxia, block tumor survival signaling, modify tumor metabolism, block growth factor signaling, slow tumor invasiveness, impair angiogenesis, or stimulate antitumor immunity. Promising agents include widely used drugs such as aspirin, metformin, and statins, offering the potential to improve outcomes, decrease radiation doses, and lower costs. Many other candidate drugs are also discussed.

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.

A pilot window-of-opportunity study of preoperative fluvastatin in localized prostate cancer

Background

Statins inhibit HMG-CoA reductase, the rate-limiting enzyme of the mevalonate pathway. Epidemiological and pre-clinical evidence support an association between statin use and delayed prostate cancer (PCa) progression. Here, we evaluated the effects of neoadjuvant fluvastatin treatment on markers of cell proliferation and apoptosis in men with localized PCa.

Methods

Thirty-three men were treated daily with 80 mg fluvastatin for 4–12 weeks in a single-arm window-of-opportunity study between diagnosis of localized PCa and radical prostatectomy (RP) (ClinicalTrials.gov: NCT01992042). Percent Ki67 and cleaved Caspase-3 (CC3)-positive cells in tumor tissues were evaluated in 23 patients by immunohistochemistry before and after treatment. Serum and intraprostatic fluvastatin concentrations were quantified by liquid chromatography-mass spectrometry.

Results

Baseline characteristics included a median prostate-specific antigen (PSA) level of 6.48 ng/mL (IQR: 4.21–10.33). The median duration of fluvastatin treatment was 49 days (range: 27–102). Median serum low-density lipoprotein levels decreased by 35% after treatment, indicating patient compliance. Median PSA decreased by 12%, but this was not statistically significant in our small cohort. The mean fluvastatin concentration measured in the serum was 0.2 μM (range: 0.0–1.1 μM), and in prostatic tissue was 8.5 nM (range: 0.0–77.0 nM). At these concentrations, fluvastatin induced PCa cell death in vitro in a dose- and time-dependent manner. In patients, fluvastatin treatment did not significantly alter intratumoral Ki67 positivity; however, a median 2.7-fold increase in CC3 positivity (95% CI: 1.9–5.0, p = 0.007) was observed in post-fluvastatin RP tissues compared with matched pre-treatment biopsy controls. In a subset analysis, this increase in CC3 was more pronounced in men on fluvastatin for >50 days.

Conclusions

Fluvastatin prior to RP achieves measurable drug concentrations in prostatic tissue and is associated with promising effects on tumor cell apoptosis. These data warrant further investigation into the anti-neoplastic effects of statins in prostate tissue.

Small-molecule drug repurposing to target DNA damage repair and response pathways

For decades genotoxic therapy has been a mainstay in the treatment of cancer, based on the understanding that the deregulated growth and genomic instability that drive malignancy also confer a shared vulnerability. Although chemotherapy and radiation can be curative, only a fraction of patients benefit, while nearly all are subjected to the harmful side-effects. Drug repurposing, defined here as retooling existing drugs and compounds as chemo or radiosensitizers, offers an attractive route to identifying otherwise non-toxic agents that can potentiate the benefits of genotoxic cancer therapy to enhance the therapeutic ratio. This review seeks to highlight recent progress in defining cellular mechanisms of the DNA damage response including damage sensing, chromatin modification, DNA repair, checkpoint signaling, and downstream survival and death pathways, as a framework to determine which drugs and natural products may offer the most potential for repurposing as chemo- and/or radiosensitizers. We point to classical examples and recent progress that have identified drugs that disrupt cellular responses to DNA damage and may offer the greatest clinical potential. The most important next steps may be to initiate prospective clinical trials toward translating these laboratory discoveries to benefit patients.

Artesunate inhibits the mevalonate pathway and promotes glioma cell senescence

Glioma is a common brain malignancy for which new drug development is urgently needed because of radiotherapy and drug resistance. Recent studies have demonstrated that artemisinin (ARS) compounds can display antiglioma activity, but the mechanisms are poorly understood. Using cell lines and mouse models, we investigated the effects of the most soluble ARS analogue artesunate (ART) on glioma cell growth, migration, distant seeding and senescence and elucidated the underlying mechanisms. Artemisinin effectively inhibited glioma cell growth, migration and distant seeding. Further investigation of the mechanisms showed that ART can influence glioma cell metabolism by affecting the nuclear localization of SREBP2 (sterol regulatory element‐binding protein 2) and the expression of its target gene HMGCR (3‐hydroxy‐3‐methylglutaryl coenzyme A reductase), the rate‐limiting enzyme of the mevalonate (MVA) pathway. Moreover, ART affected the interaction between SREBP2 and P53 and restored the expression of P21 in cells expressing wild‐type P53, thus playing a key role in cell senescence induction. In conclusion, our study demonstrated the new therapeutic potential of ART in glioma cells and showed the novel anticancer mechanisms of ARS compounds of regulating MVA metabolism and cell senescence.

Epidemiology of Prostate Cancer

Prostate cancer is the second most frequent cancer diagnosis made in men and the fifth leading cause of death worldwide. Prostate cancer may be asymptomatic at the early stage and often has an indolent course that may require only active surveillance. Based on GLOBOCAN 2018 estimates, 1,276,106 new cases of prostate cancer were reported worldwide in 2018, with higher prevalence in the developed countries. Differences in the incidence rates worldwide reflect differences in the use of diagnostic testing. Prostate cancer incidence and mortality rates are strongly related to the age with the highest incidence being seen in elderly men (> 65 years of age). African-American men have the highest incidence rates and more aggressive type of prostate cancer compared to White men. There is no evidence yet on how to prevent prostate cancer; however, it is possible to lower the risk by limiting high-fat foods, increasing the intake of vegetables and fruits and performing more exercise. Screening is highly recommended at age 45 for men with familial history and African-American men. Up-to-date statistics on prostate cancer occurrence and outcomes along with a better understanding of the etiology and causative risk factors are essential for the primary prevention of this disease.

An actionable sterol-regulated feedback loop modulates statin sensitivity in prostate cancer

OBJECTIVE

The statin family of cholesterol-lowering drugs has been shown to induce tumor-specific apoptosis by inhibiting the rate-limiting enzyme of the mevalonate (MVA) pathway, HMG-CoA reductase (HMGCR). Accumulating evidence suggests that statin use may delay prostate cancer (PCa) progression in a subset of patients; however, the determinants of statin drug sensitivity in PCa remain unclear. Our goal was to identify molecular features of statin-sensitive PCa and opportunities to potentiate statin-induced PCa cell death.

METHODS

Deregulation of HMGCR expression in PCa was evaluated by immunohistochemistry. The response of PCa cell lines to fluvastatin-mediated HMGCR inhibition was assessed using cell viability and apoptosis assays. Activation of the sterol-regulated feedback loop of the MVA pathway, which was hypothesized to modulate statin sensitivity in PCa, was also evaluated. Inhibition of this statin-induced feedback loop was performed using RNA interference or small molecule inhibitors. The achievable levels of fluvastatin in mouse prostate tissue were measured using liquid chromatography-mass spectrometry.

RESULTS

High HMGCR expression in PCa was associated with poor prognosis; however, not all PCa cell lines underwent apoptosis in response to treatment with physiologically-achievable concentrations of fluvastatin. Rather, most cell lines initiated a feedback response mediated by sterol regulatory element-binding protein 2 (SREBP2), which led to the further upregulation of HMGCR and other lipid metabolism genes. Overcoming this feedback mechanism by knocking down or inhibiting SREBP2 potentiated fluvastatin-induced PCa cell death. Notably, we demonstrated that this feedback loop is pharmacologically-actionable, as the drug dipyridamole can be used to block fluvastatin-induced SREBP activation and augment apoptosis in statin-insensitive PCa cells.

CONCLUSION

Our study implicates statin-induced SREBP2 activation as a PCa vulnerability that can be exploited for therapeutic purposes using clinically-approved agents.

Statin and metformin therapy in prostate cancer patients with hyperlipidemia who underwent radiotherapy: a population-based cohort study

Purpose

To evaluate the association between the use of statins and/or metformin and patient survival in prostate cancer patients in Taiwan.

Subjects and methods

Newly diagnosed prostate cancer patients who had hyperlipidemia and received radiotherapy were identified from the National Health Insurance Research Database 2000–2010. The survival rate was estimated by the Kaplan–Meier method. Univariate and multivariate Cox regression analyses were performed to examine the association of mortality. Sensitivity analysis was performed to assess the risk of mortality in patients with diabetes.

Results

The study included 567 patients. Patients who used statins or metformin after prostate cancer diagnosis had longer average survival times (9.3 years and 8.1 years, respectively; P=0.001) compared with patients who persistently used or used the medicines prior to cancer diagnosis. Multivariate Cox regression analysis found that patients treated with statins after cancer diagnosis were significantly associated with a lower risk of mortality (aHR =0.24, 95% CI =0.09–0.66) compared to patients who did not use statins during the study period. Patients treated with metformin after cancer diagnosis were significantly associated more with an increased risk of mortality (aHR =6.78, 95% CI =2.45–18.77) compared to patients who did not use metformin during the study period. Sensitivity analysis revealed that the average survival time was similar among different medicine use groups in patients with diabetes.

Conclusion

The finding suggests that statins and metformin use after prostate cancer diagnosis may increase survival in patients with hyperlipidemia and radiotherapy.

Statin use linked with a decrease in the conversion from high-grade prostatic intraepithelial neoplasia (HGPIN) to prostate cancer

The roles of obesity, metabolic dysregulation and systemic inflammation to advance prostate carcinogenesis are unclear. This study investigates metabolic and inflammatory factors in the transition from high-grade prostatic intraepithelial neoplasia (HGPIN) to prostate cancer (PC). We prospectively followed 160 men diagnosed with HGPIN at biopsy and therefore at high-risk and clinically monitored for PC. Analyses investigated body mass index (BMI), waist circumference, waist-hip ratio (WHR), height, fat mass, lean mass percent body fat, NSAIDs, statins, metformin, diabetes, hypertension, hypercholesterolemia representing metabolic dysregulation on the risk of a PC diagnosis during follow-up. Systemic inflammation was estimated through measurement of 13 plasma cytokine levels. Statin use was significantly linked with overall PC at follow-up [odds ratio (OR) = 0.45, (0.23, 0.91), P = 0.03], with a somewhat stronger link with high-grade [OR = 0.39, (0.15, 1.04), P = 0.06] PC compared with low-grade PC [OR = 0.50, (0.23, 1.12), P = 0.09]. Non-statin cholesterol-lowering medications, BMI, WHR, diabetes, hypertension and percent body fat were not significantly associated with PC. Although blood IL-12p70, IL-2 and IL-1β levels were significantly lower among statin users, inflammatory markers were not significantly linked with PC and did not explain the observed relationship between statins and lower PC risk. In summary, this prospective study of HGPIN patients at high risk for PC finds that statin use was significantly associated with reduced risk of PC detection at follow-up. Systemic markers of inflammation did not mediate this association, suggesting that statins affect PC progression through alternative pathways.

Targeting Tumor Metabolism With Statins During Treatment for Advanced-stage Pancreatic Cancer

INTRODUCTION

A growing body of preclinical data suggests that statins may exert potent antitumor effects, yet the interactions of these medications with standard therapies and clinical outcomes in this population is less clear. We assessed the impact of statin use on outcomes in patients with advanced-stage pancreatic adenocarcinoma undergoing various treatments.

MATERIALS AND METHODS

After institutional review board approval, we conducted a retrospective-cohort study consisting of 303 newly diagnosed advanced-stage pancreatic adenocarcinoma patients to determine the impact of statin use on outcomes. Univariate and multivariable Cox proportional hazard regression models were utilized to estimate hazard ratios (HRs). Time-to-event was estimated using Kaplan-Meier survival analysis for overall survival, distant metastasis, and locoregional failure. Baseline and active statin usage were assessed and to mitigate risk of immortal time bias, subanalysis excluding patients with under 6 months of follow-up was conducted.

RESULTS

Both prior (P=0.021) and active (P=0.030) statin usage correlated with improved survival in this cohort. Surgery, chemoradiation, and statin use improved 2-year survival rates (84.1% vs. 55.0%; P<0.001). On multivariable analysis, statin exposure was associated with overall survival (HR, 0.662; P=0.027) and trended to significance for freedom from distant metastasis (HR, 0.577; P=0.060). Comorbid conditions were not significantly associated with outcomes.

CONCLUSIONS

Statin use was associated with improved overall survival in advanced-stage pancreatic adenocarcinoma patients. This data supports previous findings in early-stage pancreatic adenocarcinoma and other cancer sites. To our knowledge this is the first report to examine the efficacy of statin use as a supplementary treatment option in advanced-stage pancreatic adenocarcinoma patients.

Serum cholesterol levels and tumor growth in a PTEN-null transgenic mouse model of prostate cancer

Background

Some, but not all, epidemiologic evidence supports a role for cholesterol, the precursor for steroid hormone synthesis, in prostate cancer. Using a PTEN-null transgenic mouse model of prostate cancer, we tested the effect of modifying serum cholesterol levels on prostate tumor development and growth. We hypothesized that serum cholesterol reduction would lower tumor androgens and slow prostate cancer growth.

Methods

PTEN^loxP/loxP-Cre⁺ mice consuming ad libitum high fat, high cholesterol diets (40% fat, 1.25% cholesterol) were randomized after weaning to receive the cholesterol uptake inhibitor, ezetimibe (30 mg/kg/day), or no intervention, and sacrificed at 2, 3 or 4 months of age. Serum cholesterol and testosterone were measured by ELISA and intraprostatic androgens by mass spectrometry. Prostate histology was graded, and proliferation and apoptosis in tumor epithelium and stroma was assessed by Ki67 and TUNEL, respectively.

Results

Ezetimibe-treated mice had lower serum cholesterol at 4 months (p=0.031). Serum cholesterol was positively correlated with prostate weight (p=0.033) and tumor epithelial proliferation (p=0.069), and negatively correlated with tumor epithelial apoptosis (p=0.004). Serum cholesterol was unrelated to body weight (p=0.195). Tumor stromal cell proliferation was reduced in the ezetimibe group (p=0.010). Increased serum cholesterol at 4 months was associated with elevated intraprostatic DHEA, testosterone and androstenedione (p=0.043, p=0.074, p=0.031, respectively). However, cholesterol reduction did not significantly affect adenocarcinoma development at 2, 3 or 4 months of age (0%, 78%, 100% in ezetimibe-treated vs. 0%, 80%, 100% in mice not receiving ezetimibe).

Conclusions

Though serum cholesterol reduction did not significantly affect the rate of adenocarcinoma development in the PTEN-null transgenic mouse model of prostate cancer, it lowered intraprostatic androgens and slowed tumor growth. These findings support a role for serum cholesterol in promoting prostate cancer growth, potentially via enhanced tumor androgen signaling, and may provide new insight into cholesterol-lowering interventions for prostate cancer treatment.

Cilia loss sensitizes cells to transformation by activating the mevalonate pathway

Although cilia loss and cell transformation are frequently observed in the early stage of tumorigenesis, the roles of cilia in cell transformation are unknown. In this study, disrupted ciliogenesis was observed in cancer cells and pancreatic cancer tissues, which facilitated oncogene-induced transformation of normal pancreatic cells (HPDE6C7) and NIH3T3 cells through activating the mevalonate (MVA) pathway. Disruption of ciliogenesis up-regulated MVA enzymes through β catenin-T cell factor (TCF) signaling, which synchronized with sterol regulatory element binding transcription factor 2 (SREBP2), and the regulation of MVA by β-catenin-TCF signaling was recapitulated in a mouse model of pancreatic ductal adenocarcinoma (PDAC) and human PDAC samples. Moreover, disruption of ciliogenesis by depleting Tg737 dramatically promoted tumorigenesis in the PDAC mouse model, driven by KrasG12D , which was inhibited by statin, an inhibitor of the MVA pathway. Collectively, this study emphasizes the crucial roles of cilia in governing the early steps of the transformation by activating the MVA pathway, suggesting that statin has therapeutic potential for pancreatic cancer treatment.

Simvastatin inhibits the development of radioresistant esophageal cancer cells by increasing the radiosensitivity and reversing EMT process via the PTEN-PI3K/AKT pathway

Acquired radioresistance compromises the efficacy of radiotherapy for carcinomas including esophageal cancer (EC), thus resulting in recurrence and poor survival. Recent research corroborated radiosensitive function of simvastatin in stem-like breast cancer cells. However, its role in EC radioresistance remains poorly elucidated. Here, we developed a radioresistant EC cell line Ec9706-R with higher resistance to irradiation relative to control Ec9706 cells. Intriguingly, Ec9706-R cells exhibited epithelial-mesenchymal transition (EMT) characteristics with high invasion and migration ability. Simvastatin sensitized radioresistance of Ec9706-R cells and suppressed cell proliferation, but aggravated radiation-induced apoptosis and caspase-3 activity. Furthermore, simvastatin reversed EMT and inhibited cell invasion and migration of Ec9706-R cells. Mechanism assay confirmed the activation of PI3K/AKT pathway after radiation, which was inhibited by simvastatin. After restoring this pathway by its activator, IGF-1, simvastatin-mediated radiosensitivity and EMT reversion were abrogated. Further assay substantiated the PTEN suppression after irradiation, which was elevated following simvastatin pre-treatment. Moreover, PTEN cessation attenuated the inhibitory effect of simvastatin on PI3K/AKT activation, and subsequently antagonized simvastatin-induced radiosensitivity and EMT reversion. Additionally, simvastatin aggravated radiation-mediated Ec9706-R tumor growth inhibition. Together, simvastatin inhibits the development of Ec9706-R cells by increasing radiosensitivity and reversing EMT via PTEN-PI3K/AKT pathway, implying a promising strategy against EC radioresistance.

HMG-CoA Reductase Inhibition Delays DNA Repair and Promotes Senescence After Tumor Irradiation

Despite significant advances in combinations of radiotherapy and chemotherapy, altered fractionation schedules and image-guided radiotherapy, many cancer patients fail to benefit from radiation. A prevailing hypothesis is that targeting repair of DNA double strand breaks (DSB) can enhance radiation effects in the tumor and overcome therapeutic resistance without incurring off-target toxicities. Unrepaired DSBs can block cancer cell proliferation, promote cancer cell death, and induce cellular senescence. Given the slow progress to date translating novel DSB repair inhibitors as radiosensitizers, we have explored drug repurposing, a proven route to improving speed, costs, and success rates of drug development. In a prior screen where we tracked resolution of ionizing radiation-induced foci (IRIF) as a proxy for DSB repair, we had identified pitavastatin (Livalo), an HMG-CoA reductase inhibitor commonly used for lipid lowering, as a candidate radiosensitizer. Here, we report that pitavastatin and other lipophilic statins are potent inhibitors of DSB repair in breast and melanoma models both in vitro and in vivo When combined with ionizing radiation, pitavastatin increased persistent DSBs, induced senescence, and enhanced acute effects of radiation on radioresistant melanoma tumors. shRNA knockdown implicated HMG-CoA reductase, farnesyl diphosphate synthase, and protein farnesyl transferase in IRIF resolution, DSB repair, and senescence. These data confirm on-target activity of statins, although via inhibition of protein prenylation rather than cholesterol biosynthesis. In light of prior studies demonstrating enhanced efficacy of radiotherapy in patients taking statins, this work argues for clinical evaluation of lipophilic statins as nontoxic radiosensitizers to enhance the benefits of image-guided radiotherapy. Mol Cancer Ther; 17(2); 407-18. ©2017 AACRSee all articles in this MCT Focus section, "Developmental Therapeutics in Radiation Oncology."

Novel Indications for Commonly Used Medications as Radiation Protectants in Spaceflight

BACKGROUND

In the space environment, the traditional radioprotective principles of time, distance, and shielding become difficult to implement. Additionally, the complex radiation environment inherent in space, the chronic exposure timeframe, and the presence of numerous confounding variables complicate the process of creating appropriate risk models for astronaut exposure. Pharmaceutical options hold tremendous promise to attenuate acute and late effects of radiation exposure in the astronaut population. Pharmaceuticals currently approved for other indications may also offer radiation protection, modulation, or mitigation properties along with a well-established safety profile. Currently there are only three agents which have been clinically approved to be employed for radiation exposure, and these only for very narrow indications. This review identifies a number of agents currently approved by the U.S. Food and Drug Administration (FDA) which could warrant further investigation for use in astronauts. Specifically, we examine preclinical and clinical evidence for statins, nonsteroidal anti-inflammatory drugs (NSAIDs), angiotensin converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), metformin, calcium channel blockers, β adrenergic receptor blockers, fingolimod, N-acetylcysteine, and pentoxifylline as potential radiation countermeasures.McLaughlin MF, Donoviel DB, Jones JA. Novel indications for commonly used medications as radiation protectants in spaceflight. Aerosp Med Hum Perform. 2017; 88(7):665-676.

Linking CHHiP prostate cancer RCT with GP records: A study proposal to investigate the effect of co-morbidities and medications on long-term symptoms and radiotherapy-related toxicity

Background

Patients receiving cancer treatment often have one or more co-morbid conditions that are treated pharmacologically. Co-morbidities are recorded in clinical trials usually only at baseline. However, co-morbidities evolve and new ones emerge during cancer treatment. The interaction between multi-morbidity and cancer recovery is significant but poorly understood.

Purpose

To investigate the effect of co-morbidities (e.g. cardiovascular and diabetes) and medications (e.g. statins, antihypertensives, metformin) on radiotherapy-related toxicity and long-term symptoms in order to identify potential risk factors. The possible protective effect of medications such as statins or antihypertensives in reducing radiotherapy-related toxicity will also be explored.

Methods

Two datasets will be linked. (1) CHHiP (Conventional or Hypofractionated High Dose Intensity Modulated Radiotherapy for Prostate Cancer) randomised control trial. CHHiP contains pelvic symptoms and radiation-related toxicity reported by patients and clinicians. (2) GP (General Practice) data from RCGP RSC (Royal College of General Practitioners Research and Surveillance Centre). The GP records of CHHiP patients will be extracted, including cardiovascular co-morbidities, diabetes and prescription medications. Statistical analysis of the combined dataset will be performed in order to investigate the effect.

Conclusions

Linking two sources of healthcare data is an exciting area of big healthcare data research. With limited data in clinical trials (not all clinical trials collect information on co-morbidities or medications) and limited lengths of follow-up, linking different sources of information is increasingly needed to investigate long-term outcomes. With increasing pressures to collect detailed information in clinical trials (e.g. co-morbidities, medications), linkage to routinely collected data offers the potential to support efficient conduct of clinical trials.

Effects of statins on cancer mortality and progression: A systematic review and meta-analysis of 95 cohorts including 1,111,407 individuals

Statins have been implicated in the regulation of cell proliferation, apoptosis and tumor progression in cancer patients and statin use at the time of cancer diagnosis has been reported to be associated with reduced cancer risk and improved survival, irrespective of concomitant anti-cancer therapy. A systematic literature search of relevant databases through May 2015 was conducted to identify studies assessing the prognostic impact of statin use on prognostic outcomes in cancer patients. Literature search identified 95 cohort studies that met the inclusion criteria. A meta-analysis of 55 articles showed that statin use was significantly associated with decreased risk of all-cause mortality (HR 0.70, 95% Cl 0.66 to 0.74) compared with nonusers. The observed pooled estimates were retained for cancer-specific mortality (HR 0.60, 95% Cl 0.47 to 0.77), progression-free survival (HR 0.67, 95% Cl 0.56 to 0.81), recurrence-free survial (HR 0.74, 95% Cl 0.65 to 0.83) and disease-free survival (HR 0.53, 95% Cl 0.40 to 0.72). These associations almost remained consistent across those outcomes when stratified by publication type, tumour location, study design, sample size, initiation of statins, disease stage, research country, follow-up duration or research hospital involved. Subgroup analyses according to initiation of statins showed postdiagnosis statin users (HR 0.65, 95% Cl 0.54 to 0.79) gained significantly more recurrence-free survival benefit than prediagnosis statin users (HR 0.86, 95% Cl 0.77 to 0.96) (p for interaction = 0.018). Statin therapy has potential survival benefit for patients with malignancy. Further large-scale prospective studies emphasising survival outcomes of individual cancer type are strongly encouraged.

Statin Use, Serum Lipids, and Prostate Inflammation in Men with a Negative Prostate Biopsy: Results from the REDUCE Trial

Statin use is associated with lower advanced prostate cancer risk. In addition to cholesterol lowering, statins have systemic anti-inflammatory properties. However, their effect on histologic prostate inflammation is not well understood, particularly among men at increased prostate cancer risk but with a negative prostate biopsy. We examined associations between serum lipid levels, statin use, and histologic prostate inflammation using data from 6,655 men with a negative baseline prostate biopsy in the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial. Statin use and lipid levels [total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides] were assessed at baseline. Inflammation was assessed by central review. Logistic regression was used to examine the effects of lipids and statin use on presence and extent of chronic and acute prostate inflammation [none, moderate (<20%), severe (≥20% biopsy cores)]. Chronic and acute inflammation affected 77% and 15% of men, respectively. Men with high HDL (≥60 vs. <40 mg/dL) had reduced presence of acute inflammation [OR, 0.79; 95% confidence interval (CI), 0.63-0.99] and were less likely to have severe acute inflammation (OR, 0.66; 95% CI, 0.45-0.97), but there were no other associations between lipids and inflammation. Statin users had reduced presence of chronic inflammation (OR, 0.81; 95% CI, 0.69-0.95) and were less likely to have severe chronic (OR, 0.80; 95% CI, 0.68-0.95) and severe acute inflammation (OR, 0.73; 95% CI, 0.53-1.00), relative to non-users. Given the possible role for inflammation in prostate cancer, the inverse association between statins and prostate inflammation suggests a mechanism linking statins with lower advanced prostate cancer risk. Cancer Prev Res; 10(6); 319-26. ©2017 AACR.

Prognostic Role of Preoperative Serum Lipid Levels in Patients Undergoing Radical Prostatectomy for Clinically Localized Prostate Cancer

BACKGROUND

The prognostic role of preoperative serum lipid levels in patients undergoing radical prostatectomy (RP) for clinically localized prostate cancer (PCa) is unclear. The aim of the present study was to investigate preoperative serum lipid levels in patients with clinically localized PCa undergoing RP and their association with clinicopathological features and oncological outcome.

METHODS

Preoperative lipid levels (total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides) and statin use from consecutive patients with clinically localized PCa undergoing RP in a tertiary referral center between 2008 and 2015 were recorded and patients were followed prospectively. Logistic regression analysis was used to test the association between lipid levels and clinicopathological parameters. Lipid values were analyzed both as continuous and dichotomized variables. Univariable and multivariable Cox regression analyses were performed to identify predictors for recurrence-free survival (RFS). Recurrence was defined as rising and verified PSA levels >0.1 ng/ml.

RESULTS

Our cohort consisted of 371 men with a median age of 63 years (range 41-78 years) and a median preoperative PSA value of 6.79 ng/ml (0.43-81.4 ng/ml). Median follow-up was 28 months (1-64). No association was found between lipid levels and adverse pathological characteristics such as ≥pT3, Gleason score ≥8, positive nodal status and positive surgical margins. Recurrence occurred in 49 patients (15.4%) at a median time of 18 months (2-51 month). Compared to low LDL cholesterol, high LDL cholesterol was associated with longer RFS in univariable analysis (continuous: Hazard Ratio (HR): 0.67, 95%-Confidence Interval (CI): 0.47-0.96, P = 0.03; 3 mM cut-point: HR: 0.44, 95%-CI: 0.24-0.79, P = 0.006). Neither levels of other lipids, nor statin use were associated with RFS. Preoperative LDL cholesterol remained an independent predictor for PCa recurrence in a multivariable model adjusted for age, preoperative PSA, statin use, tumor stage, Gleason score, nodal status and surgical margin status (continuous: HR: 0.66, 95%-CI: 0.44-0.99, P = 0.04; 3 mM cut-point: HR: 0.41, 95%-CI: 0.21-0.78, P = 0.007).

CONCLUSIONS

This is the first prospective study showing the potential adverse and independent prognostic role of low preoperative LDL cholesterol levels in patients with localized PCa undergoing RP. Prostate 77:549-556, 2017. © 2017 Wiley Periodicals, Inc.

Statin Use in Prostate Cancer: An Update

3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, known as statins, are commonly prescribed for the treatment of hypercholesterolemia and cardiovascular disease. A systematic review was conducted using the keywords “statin and prostate cancer” within the title search engines including PubMed, Web of Science, and the Cochrane Library for relevant research work published between 2004 and December 2015. Although still premature, accumulating clinical evidence suggests that statin use may be beneficial in the prevention and/or treatment of prostate cancer. These human studies consist of meta-analyses of secondary endpoints obtained from randomized, controlled cardiovascular disease clinical trials of statins, patient database, observational studies, and a few, small case–control studies, directly addressing statin use on prostate cancer pathology and recurrence. This review summarizes and discusses the recent clinical literature on statins and prostate cancer with a recommendation to move forward with randomized, placebo-controlled clinical trials, investigating the use of statins. Additional preclinical testing of statins on prostate cancer cell lines and in vivo models is needed to elucidate pathways and determine its efficacy for prevention and/or treatment of prostate cancer, more specifically, the difference in the effectiveness of lipophilic versus hydrophilic statins in prostate cancer.

The effect of statins on prostate cancer recurrence and mortality after definitive therapy: a systematic review and meta-analysis

In this work, we aim to further analyze the association of statins use with biochemical recurrence (BCR) of prostate cancer (PCa) and PCa-specific mortality after definitive therapy. A systematic literature search of PubMed, MEDLINE, and EMBASE through Jul 2015 was conducted. Pooled Hazard ratio (HR) estimates with corresponding 95% confidence intervals (CIs) were calculated using random-effects model. STATA version 10 (Stata corporation, college station, TX) was employed to conduct all statistical analyses. A total of 22 and 8 studies contributed to the biochemical recurrence analysis and PCa-specific mortality, respectively. 13 trials were included for BCR-free survival analysis. The combined result showed statins users had lowered 12% BCR risk of PCa compared with non-users (HR = 0.88, 95%CI: 0.765–0.998) (p < 0.05). The association was null among the men who underwent radical prostatectomy as primary therapy (HR = 0.96, 95%CI: 0.83–1.09), while the improved outcomes had be seen among patients who received radiation therapy (HR = 0.67, 95%CI: 0.48–0.86). After excluding the patients undergoing ADT, participants did not benefit from statins use (HR = 0.94, 95%CI: 0.77–1.11). Meanwhile, long-term statins using did not alter recurrence risk. A lower risk of prostate cancer-specific mortality was observed among statins users (HR = 0.68, 95%CI: 0.56–0.80). There was a plausible trend towards increasing the BCR-free survival rate among statins users.

Does comorbidity interact with prostate cancer to increase mortality? A Danish cohort study of 45 326 prostate cancer patients diagnosed during 1995-2011

BACKGROUND

Many prostate cancer patients die of other causes, but it remains unknown whether comorbidity interacts synergistically with prostate cancer to increase the mortality rate beyond that explained by the individual risks of comorbidity and prostate cancer.

METHODS

A nationwide cohort study of 45 326 Danish prostate cancer patients diagnosed during 1995-2011, each matched to approximately five men from the general population on age and individual comorbidities in the Charlson Comorbidity Index (CCI). We calculated five-year mortality rates and interaction contrasts as a measure of the excess mortality rate explained by synergy between prostate cancer and comorbidity.

RESULTS

Five-year mortality was 46.8% in prostate cancer patients and 25.8% in matched men from the general population. For prostate cancer patients with a CCI score of 2-3, the mortality rate was 250 per 1000 person-years [95% confidence interval (CI): 236, 263], and interaction between comorbidity and prostate cancer accounted for 20% of the total mortality rate (50 deaths per 1000 person-years, 95% CI 35, 65) in the first year following cancer diagnosis. The interaction was mainly present for patients with metastatic disease and those not treated with prostatectomy.

CONCLUSION

Up to 20% of all deaths among men who had both prostate cancer and comorbidities could be explained by the comorbidity-prostate cancer interaction. The mortality attributable to comorbidity itself and the mortality attributable to the interaction may be reduced by successful treatment of the comorbidity.

Hypercholesterolemia Is Associated with a Shorter Time to Castration-Resistant Prostate Cancer in Patients Who Have Undergone Androgen Deprivation Therapy

Purpose

The goal of this study was to investigate the association between hypercholesterolemia and the time required for progression to castration-resistant prostate cancer (CRPC) in patients who have undergone androgen deprivation therapy (ADT).

Materials and Methods

Data from 154 patients with prostate cancer between 2005 and 2012 were reviewed retrospectively. ADT was employed as a treatment modality for these patients either due to multiple bone metastases at the time of diagnosis or due to old age in combination with other morbidities. Serum cholesterol levels and statin use were reviewed. We analyzed the factors associated with the development of CRPC after ADT treatment. The mean follow-up period was 34.8 months.

Results

The mean age of the patients was 71.3 years old and their mean prostate-specific antigen level was 141.8±212.6 ng/mL. Their mean cholesterol level was 175.9±37.7 mg/dL, and 14 patients (9.1%) were statin users. CRPC developed in 44 patients (28.6%), and the mean duration from ADT treatment to CRPC was 24.1 months. In a multivariate analysis, hypercholesterolemia was associated with the development of CRPC (hazard ratio [HR]=1.017, p<0.001), depending on clinical T stage (p=0.005) and the presence of bone metastasis (p<0.001). A subanalysis showed that hypercholesterolemia was associated with the development of CRPC in patients with bone metastasis (HR=1.032, p<0.001), but not in patients without bone metastasis.

Conclusions

Hypercholesterolemia may be associated with the development of CRPC after ADT in patients with bone metastasis. Further studies with longer follow-up periods and larger samples are needed to validate this finding.

Low-density lipoprotein receptors play an important role in the inhibition of prostate cancer cell proliferation by statins

Background

There are some reports about the antitumor effects of statins in these days. Statins decrease the level of cholesterol in the blood by inhibiting 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Inhibition of this enzyme decreases intracellular cholesterol synthesis. Thus, the expression of low-density lipoprotein receptor (LDLr) is increased to import more cholesterol from the bloodstream. In this study, we assessed the effects of statins on the proliferation of prostate cancer cells, and studied the relationship between the expression of LDLr and the effects of statins.

Methods

Simvastatin was used in the experiments. We studied the effect of simvastatin on PC-3 and LNCaP cell proliferation using the MTS assay, and evaluated the expression of LDLr after administration of simvastatin by quantitative polymerase chain reaction and Western blotting. Intracellular cholesterol levels in the prostate cancer cells were measured after administration of simvastatin. Furthermore, small interfering RNA (siRNA) was used to knockdown the gene expression of LDLr.

Results

In PC-3 cells, simvastatin inhibited cell proliferation. In LNCaP cells, only a high concentration of simvastatin (100μM) inhibited cell proliferation. In LNCaP cells, the protein level of LDLr was increased by simvastatin. In PC-3 cells, the protein levels of LDLr were unregulated. In PC-3 cells, but not in LNCaP cells, intracellular cholesterol levels were significantly decreased by simvastatin. After knocking down LDLr expression by siRNA, intracellular cholesterol levels were decreased, and cell proliferation was inhibited by simvastatin in LNCaP cells.

Conclusion

Simvastatin inhibited prostate cancer cell growth by decreasing cellular cholesterol and could be more effective in androgen-independent prostate cancer, where there is loss of regulation of LDLr expression. LDLr was shown to play an important role in the statin-induced inhibition of prostate cancer cell proliferation. These results suggest that future studies evaluating the cholesterol-lowering effects of statin may lead to new approaches to the prevention and treatment of prostate cancer.

Racial Differences in the Association Between Preoperative Serum Cholesterol and Prostate Cancer Recurrence: Results from the SEARCH Database

BACKGROUND

Black men are disproportionately affected by both cardiovascular disease and prostate cancer. Epidemiologic evidence linking dyslipidemia, an established cardiovascular risk factor, and prostate cancer progression is mixed. As existing studies were conducted in predominantly non-black populations, research on black men is lacking.

METHODS

We identified 628 black and 1,020 non-black men who underwent radical prostatectomy and never used statins before surgery in the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Median follow-up was 2.9 years. The impact of preoperative hypercholesterolemia on risk of biochemical recurrence was examined using multivariable, race-stratified proportional hazards. In secondary analysis, we examined associations with low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides, overall and among men with dyslipidemia.

RESULTS

High cholesterol was associated with increased risk of recurrence in black [HR(per10 mg/dL) 1.06; 95% confidence interval (CI), 1.02-1.11] but not non-black men (HR(per10 mg/dL) 0.99; 95% CI, 0.95-1.03; P(interaction) = 0.011). Elevated triglycerides were associated with increased risk in both black and non-black men (HR(per10 mg/dL) 1.02; 95% CI, 1.00-1.03 and 1.02; 95% CI, 1.00-1.02, respectively; P(interaction) = 0.458). There were no significant associations between LDL or HDL and recurrence risk in either race. Associations with cholesterol, LDL, and triglycerides were similar among men with dyslipidemia, but low HDL was associated with increased risk of recurrence in black, but not non-black men with dyslipidemia (P(interaction) = 0.047).

CONCLUSION

Elevated cholesterol was a risk factor for recurrence in black but not non-black men, whereas high triglycerides were associated with increased risk regardless of race.

IMPACT

Significantly contrasting associations by race may provide insight into prostate cancer racial disparities.