Statin use and the risk of breast and prostate cancer

Association Between Statin Exposure and Incidence and Prognosis of Prostate Cancer: A Meta-analysis Based on Observational Studies

It is widely thought that statins have huge therapeutic potential against prostate cancer (PCA). This study aimed to investigate the effect of statin exposure on PCA incidence and prognosis. PubMed, Web of Science, Embase, and Cochrane databases were searched for observational studies on the association between statin exposure and PCA from inception until July 2022. The primary endpoints were the incidence of PCA and the survival rate. A total of 21 studies were included in this meta-analysis. The pooled estimates showed that exposure to hydrophilic statins was not associated with the incidence of PCA (odds ratio [OR]=0.94, 95% CI=0.88-1.01, P =0.075), while the incidence of PCA was significantly decreased in populations exposed to lipophilic statins compared with the nonexposed group (OR=0.94, 95% CI=0.90-0.98, P =0.001), mainly in Western countries (OR=0.94, 95% CI=0.91-0.98, P =0.006). Subgroup analysis showed that simvastatin (OR=0.83, 95% CI=0.71-0.97, P =0.016) effectively reduced the incidence of PCA. The prognosis of PCA in patients exposed to both hydrophilic (hazard ratio [HR]=0.57, 95% CI=0.49-0.66, P <0.001) and lipophilic (HR=0.65, 95% CI=0.58-0.73, P <0.001) statins were better than in the nonexposed group, and this improvement was more significant in the East than in Western countries. This study demonstrates that statins can reduce the incidence of PCA and improve prognosis, and are affected by population region and statin properties (hydrophilic and lipophilic).

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.

Effect of statins use on risk and prognosis of breast cancer: a meta-analysis

The findings regarding the association between statins use and breast cancer are inconsistent. Given the widely and long-term use of statins as first choice drug for dyslipidemia, we conducted this meta-analysis for better understanding the associations between statins use and the risk and prognosis of breast cancer. Articles regarding effect of statins use on risk, prognosis of breast cancer and published before January 2021 were searched in the following databases: Web of Science, PubMed, EMBASE, Medline and Google Scholar. Odds ratios (ORs)/relative risks (RRs) or hazard ratios (HRs) and their 95% confidence intervals (CIs) were computed to generate a pooled effect size and 95% CI. The meta-analysis showed no significant association between statins use and risk of breast cancer (OR/RR = 1.02; 95% CI, 0.97-1.08; I2 = 76.1%; P < 0.001). The meta-analysis showed that statins use was associated with lower breast cancer recurrence, all-cause mortality and disease-specific mortality (breast cancer recurrence: HR = 0.75; 95% CI, 0.67-0.84; I2 = 31.7%; P = 0.154; all-cause mortality: HR = 0.82; 95% CI, 0.77-0.89; I2 = 67.5%; P < 0.001; and disease-specific mortality: HR = 0.82; 95% CI, 0.72-0.93; I2 = 83.6%; P < 0.001). Overall, in this report we demonstrated that the use of statins can improve the prognosis of breast cancer patients including lower risks of breast cancer recurrence, all-cause and cancer-specific mortality, though statins therapy may not have an impact on reducing the risk of breast cancer.

Lactate dehydrogenase B regulates macrophage metabolism in the tumor microenvironment

Background: Glucose metabolism in the tumor-microenvironment is a fundamental hallmark for tumor growth and intervention therein remains an attractive option for anti-tumor therapy. Whether tumor-derived factors such as microRNAs (miRs) regulate glucose metabolism in stromal cells, especially in tumor-associated macrophages (TAMs), to hijack them for trophic support, remains elusive.

Methods: Ago-RIP-Seq identified macrophage lactate dehydrogenase B (LDHB) as a target of tumor-derived miR-375 in both 2D/3D cocultures and in murine TAMs from a xenograft mouse model. The prognostic value was analyzed by ISH and multiplex IHC of breast cancer patient tissues. Functional consequences of the miR-375-LDHB axis in TAMs were investigated upon mimic/antagomir treatment by live metabolic flux assays, GC/MS, qPCR, Western blot, lentiviral knockdown and FACS. The therapeutic potential of a combinatorial miR-375-decoy/simvastatin treatment was validated by live cell imaging.

Results: Macrophage LDHB decreased in murine and human breast carcinoma. LDHB downregulation increase aerobic glycolysis and lactagenesis in TAMs in response to tumor-derived miR-375. Lactagenesis reduced fatty acid synthesis but activated SREBP2, which enhanced cholesterol biosynthesis in macrophages. LDHB downregulation skewed TAMs to function as a lactate and sterol/oxysterol source for the proliferation of tumor cells. Restoring of LDHB expression potentiated inhibitory effects of simvastatin on tumor cell proliferation.

Conclusion: Our findings identified a crucial role of LDHB in macrophages and established tumor-derived miR-375 as a novel regulator of macrophage metabolism in breast cancer, which might pave the way for strategies of combinatorial cancer cell/stroma cell interventions.

Correlation of LAMA3 with onset and prognosis of ovarian cancer

Correlation of laminin subunit α3 (LAMA3) gene with onset and prognosis of ovarian cancer was investigated. In total, 210 ovarian cancer patients who received surgical resection in West China Second Hospital from March 2011 to March 2013 were randomly selected, and another 160 non-ovarian cancer patients who needed ovariectomy were also selected. The relative expression of LAMA3 gene was compared via quantitative polymerase chain reaction (qPCR) in carcinoma tissues, para-carcinoma tissues and non-carcinoma normal tissues in ovarian cancer patients. The methylation level was compared among the above three tissue types. The correlation between the mutation site rs12373237 in LAMA3 gene and onset was analyzed. The expression of laminin in ovarian cancer was detected using immunohistochemistry. Moreover, the 5-year survival rate after operation was recorded and the survival curve was plotted. The expression level of LAMA3 was lower in carcinoma tissues than those in normal tissues and para-carcinoma tissues (P<0.05). The methylation degree was lower in para-carcinoma tissues and normal tissues than that in carcinoma tissues (P<0.05). The CC homozygous mutation of rs12373237 was highly correlated with the onset of ovarian cancer (OR=4.333, P=0.028). The expression of LAMA3 was classified via immunohistochemistry, and the number in high-expression group (63.8%) was larger than that in low-expression group (36.2%) (P<0.05). According to the analysis of 5-year survival rate, the recurrence-free survival rate and overall survival rate in LAMA3 high-expression group were significantly higher than those in LAMA3 low-expression group (P<0.05). The expression level and base mutation of LAMA3 gene can change the level of laminin, which have a certain influence on the onset and prognosis of ovarian cancer.

The Potential of Isoprenoids in Adjuvant Cancer Therapy to Reduce Adverse Effects of Statins

The mevalonate pathway provides sterols for membrane structure and nonsterol intermediates for the post-translational modification and membrane anchorage of growth-related proteins, including the Ras, Rac, and Rho GTPase family. Mevalonate-derived products are also essential for the Hedgehog pathway, steroid hormone signaling, and the nuclear localization of Yes-associated protein and transcriptional co-activator with PDZ-binding motif, all of which playing roles in tumorigenesis and cancer stem cell function. The phosphatidylinositol-4,5-bisphosphate 3-kinase-AKT-mammalian target of rapamycin complex 1 pathway, p53 with gain-of-function mutation, and oncoprotein MYC upregulate the mevalonate pathway, whereas adenosine monophosphate-activated protein kinase and tumor suppressor protein RB are the downregulators. The rate-limiting enzyme, 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), is under a multivalent regulation. Sterol regulatory element binding protein 2 mediates the sterol-controlled transcriptional downregulation of HMGCR. UbiA prenyltransferase domain-containing protein-1 regulates the ubiquitination and proteasome-mediated degradation of HMGCR, which is accelerated by 24, 25-dihydrolanosterol and the diterpene geranylgeraniol. Statins, competitive inhibitors of HMGCR, deplete cells of mevalonate-derived intermediates and consequently inhibit cell proliferation and induce apoptosis. Clinical application of statins is marred by dose-limiting toxicities and mixed outcomes on cancer risk, survival and mortality, partially resulting from the statin-mediated compensatory upregulation of HMGCR and indiscriminate inhibition of HMGCR in normal and tumor cells. Tumor HMGCR is resistant to the sterol-mediated transcriptional control; consequently, HMGCR is upregulated in cancers derived from adrenal gland, blood and lymph, brain, breast, colon, connective tissue, embryo, esophagus, liver, lung, ovary, pancreas, prostate, skin, and stomach. Nevertheless, tumor HMGCR remains sensitive to isoprenoid-mediated degradation. Isoprenoids including monoterpenes (carvacrol, L-carvone, geraniol, perillyl alcohol), sesquiterpenes (cacalol, farnesol, β-ionone), diterpene (geranylgeranyl acetone), “mixed” isoprenoids (tocotrienols), and their derivatives suppress the growth of tumor cells with little impact on non-malignant cells. In cancer cells derived from breast, colon, liver, mesothelium, prostate, pancreas, and skin, statins and isoprenoids, including tocotrienols, geraniol, limonene, β-ionone and perillyl alcohol, synergistically suppress cell proliferation and associated signaling pathways. A blend of dietary lovastatin and δ-tocotrienol, each at no-effect doses, suppress the growth of implanted murine B16 melanomas in C57BL6 mice. Isoprenoids have potential as adjuvant agents to reduce the toxicities of statins in cancer prevention or therapy.

Effects of statins on the chemoresistance-The antagonistic drug-drug interactions versus the anti-cancer effects

There has been growing interest in the potential anti-cancer activity of statins based on evidence of their anti-proliferative, pro-apoptotic, and radiosensitizing properties, but no studies have focused on the effects of statins on the chemoresistance. In spite of their direct cytostatic/cytotoxic effects on the cancer cells, statins via drug interactions may affect therapeutic effects of the chemotherapy agents and so cause chemoresistance in cancer cells. Here, we aim to present the molecular mechanisms underlying cytotoxic effects of statins on the cancer cells against those mechanisms by which statins may lead to chemoresistance, in order to clarify whether the positive effects of the co-treatment of statins on the efficiency of chemotherapeutic agents is due to the natural anti-cancer effects of statins or it is due to increasing the cellular concentrations of chemotherapy drugs in cancer cells.

The effect of genetic variants on the relationship between statins and breast cancer in postmenopausal women in the Women's Health Initiative observational study

PURPOSE

Statins have been postulated to have chemopreventive activity against breast cancer. We evaluated whether germline genetic polymorphisms modified the relationship between statins and breast cancer risk using data from the Women's Health Initiative. We evaluated these interactions using both candidate gene and agnostic genome-wide approaches.

METHODS

To identify candidate gene-statin interactions, we tested interactions between 22 SNPS in nine candidate genes implicated in the effect of statins on lipid metabolism in 1687 cases and 1687 controls. We then evaluated statin use interaction with the remaining 30,380 SNPs available in this sample from the CGEMS GWAS study.

RESULTS

After adjusting for multiple comparisons, no SNP interactions with statin usage and risk of breast cancer were statistically significant in either the candidate genes or genome-wide approaches.

CONCLUSIONS

We found no evidence of SNP interactions with statin usage for breast cancer risk in a population of 3374 individuals. These results suggest that genome-wide common genetic variants do not moderate the association between statin usage and breast cancer in the population of women in the Women's Health Initiative.

Cholesterol and Its Metabolites in Tumor Growth: Therapeutic Potential of Statins in Cancer Treatment

Cholesterol is essential for cell function and viability. It is a component of the plasma membrane and lipid rafts and is a precursor for bile acids, steroid hormones, and Vitamin D. As a ligand for estrogen-related receptor alpha (ESRRA), cholesterol becomes a signaling molecule. Furthermore, cholesterol-derived oxysterols activate liver X receptors (LXRs) or estrogen receptors (ERs). Several studies performed in cancer cells reveal that cholesterol synthesis is enhanced compared to normal cells. Additionally, high serum cholesterol levels are associated with increased risk for many cancers, but thus far, clinical trials with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have had mixed results. Statins inhibit cholesterol synthesis within cells through the inhibition of HMG-CoA reductase, the rate-limiting enzyme in the mevalonate and cholesterol synthetic pathway. Many downstream products of mevalonate have a role in cell proliferation, since they are required for maintenance of membrane integrity; signaling, as some proteins to be active must undergo prenylation; protein synthesis, as isopentenyladenine is an essential substrate for the modification of certain tRNAs; and cell-cycle progression. In this review starting from recent acquired findings on the role that cholesterol and its metabolites fulfill in the contest of cancer cells, we discuss the results of studies focused to investigate the use of statins in order to prevent cancer growth and metastasis.

Exploring association between statin use and breast cancer risk: an updated meta-analysis

PURPOSE

The benefits of statin treatment for preventing cardiac disease are well established. However, preclinical studies suggested that statins may influence mammary cancer growth, but the clinical evidence is still inconsistent. We, therefore, performed an updated meta-analysis to provide a precise estimate of the risk of breast cancer in individuals undergoing statin therapy.

METHODS

For this meta-analysis, we searched PubMed, the Cochrane Library, Web of Science, Embase, and CINAHL for published studies up to January 31, 2017. Articles were included if they (1) were published in English; (2) had an observational study design with individual-level exposure and outcome data, examined the effect of statin therapy, and reported the incidence of breast cancer; and (3) reported estimates of either the relative risk, odds ratios, or hazard ratios with 95% confidence intervals (CIs). We used random-effect models to pool the estimates.

RESULTS

Of 2754 unique abstracts, 39 were selected for full-text review, and 36 studies reporting on 121,399 patients met all inclusion criteria. The overall pooled risks of breast cancer in patients using statins were 0.94 (95% CI 0.86-1.03) in random-effect models with significant heterogeneity between estimates (I ² = 83.79%, p = 0.0001). However, we also stratified by region, the duration of statin therapy, methodological design, statin properties, and individual stain use.

CONCLUSIONS

Our results suggest that there is no association between statin use and breast cancer risk. However, observational studies cannot clarify whether the observed epidemiologic association is a causal effect or the result of some unmeasured confounding variable. Therefore, more research is needed.

Interaction between Comorbidity and Cancer

Background

Older patients have an average of three comorbidities in addition to their cancer. Oncologic studies have usually ignored this aspect when adjusting for confounders. There is mounting evidence that comorbidity interacts with risk, survival, disease progression, and treatment of elderly patients with cancer. The strength of many of these interactions increases with age.

Methods

A review of the literature was undertaken regarding two of these interactions: cancer risk and prognosis.

Results

In older patients, the risk and behavior of cancer can be strongly affected by comorbidities and their related treatment. Rather than a blanket effect, this effect might be attached to groups of syndromes with common pathophysiologic mechanisms. This is notably true for metabolic disorders and inflammatory diseases.

Conclusions

In addition to focusing on the influence of cancer treatment on comorbidity or on the effect of comorbidity in delivering cancer treatment, future endeavors will need to consider the direct impact of comorbidity on the risk and the behavior of the cancer in elderly patients.

The balance between induction and inhibition of mevalonate pathway regulates cancer suppression by statins: A review of molecular mechanisms

Statins are widely used drugs for their role in decreasing cholesterol in hypercholesterolemic patients. Statins through inhibition of Hydroxy Methyl Glutaryl-CoA Reductase (HMGCR), the main enzyme of the cholesterol biosynthesis pathway, inhibit mevalonate pathway that provides isoprenoids for prenylation of different proteins such as Ras superfamily which has an essential role in cancer developing. Inhibition of the mevalonate/isoprenoid pathway is the cause of the cholesterol independent effects of statins or pleotropic effects. Depending on their penetrance into the extra-hepatic cells, statins have different effects on mevalonate/isoprenoid pathway. Lipophilic statins diffuse into all cells and hydrophilic ones use a variety of membrane transporters to gain access to cells other than hepatocytes. It has been suggested that the lower accessibility of statins for extra-hepatic tissues may result in the compensatory induction of mevalonate/isoprenoid pathway and so cancer developing. However, most of the population-based studies have demonstrated that statins have no effect on cancer developing, even decrease the risk of different types of cancer. In this review we focus on the cancer developing "potentials" and the anti-cancer "activities" of statins regarding the effects of statins on mevalonate/isoprenoid pathway in the liver and extra-hepatic tissues.

Evidence for Detection Bias by Medication Use in a Cohort Study of Breast Cancer Survivors

In previous studies, we found modestly decreased and increased risks of second breast cancer events with the use of statins and antibiotics, respectively, after adjustment for surveillance mammography. We evaluated detection bias by comparing receipt of surveillance mammography among users of these 2 disparate classes of medication. Adult women diagnosed with early-stage breast cancer during 1990-2008 (n = 3,965) while enrolled in an integrated health-care plan (Group Health Cooperative; Washington State) were followed for up to 10 years in the Commonly Used Medications and Breast Cancer Outcomes (COMBO) Study. Categories of antibiotic use included infrequent (1-3 dispensings/12 months) and frequent (≥4 dispensings/12 months) use, and categories of statin use included less adherent (1 dispensing/6 months) and adherent (≥2 dispensings/6 months). We examined associations between medication use and surveillance mammography using multivariable generalized estimating equations and evaluated the impact of adjusting for surveillance within Cox proportional hazard models. Frequent antibiotic users were less likely to receive surveillance mammography (odds ratio (OR) = 0.90, 95% confidence interval (CI): 0.82, 0.99) than were nonusers; no association was found among infrequent users (OR = 0.96, 95% CI: 0.90, 1.03). Adherent statin use was associated with more surveillance compared with nonuse (OR = 1.11, 95% CI: 1.01, 1.25), but less adherent statin use was not (OR = 1.03, 95% CI: 0.81, 1.31). No difference in associations between medications of interest and second breast cancer events was observed when surveillance was removed from otherwise adjusted models. The influence of detection bias by medication use warrants further exploration.

Triple-negative breast cancer: is there a treatment on the horizon?

Triple-negative breast cancer (TNBC), which accounts for 15-20% of all breast cancers, does not express estrogen receptor (ER) or progesterone receptor (PR) and lacks human epidermal growth factor receptor 2 (HER2) overexpression or amplification. These tumors have a more aggressive phenotype and a poorer prognosis due to the high propensity for metastatic progression and absence of specific targeted treatments. Patients with TNBC do not benefit from hormonal or trastuzumab-based targeted therapies because of the loss of target receptors. Although these patients respond to chemotherapeutic agents such as taxanes and anthracyclines better than other subtypes of breast cancer, prognosis remains poor. A group of targeted therapies under investigation showed favorable results in TNBC, especially in cancers with BRCA mutation. The lipid-lowering statins (3-hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitors), including lovastatin and simvastatin, have been shown to preferentially target TNBC compared with non-TNBC. These statins hold great promise for the management of TNBC. Only with the understanding of the molecular basis for the preference of statins for TNBC and more investigations in clinical trials can they be reformulated into a clinically approved drug against TNBC.

Effect of Lipophilic and Hydrophilic Statins on Breast Cancer Risk in Thai Women: A Cross-sectional Study

Background: Statins are proposed as a chemoprevention agent for breast cancer due to their anti-inflammatory effect. The effects of lipophilic and hydrophilic statins on breast cancer risk might be different due to their different pharmacologic properties. Therefore, this study aimed to assess a casual-effect of lipophilic and hydrophilic statins on breast cancer risk using a counterfactual framework approach.

Methods: A cross-sectional study of 15,718 women who were screened for breast cancer at Mammographic center, Ramathibodi Hospital, Bangkok, Thailand, was conducted during September 2011 to 2012. A counterfactual framework approach was applied to assess causal effects of treatments (i.e., lipophilic and hydrophilic statins) on outcome (i.e. breast cancer). Multi-logit and logistic regression models were used for treatment and outcome models, respectively. An inverse probability weight regression analysis (IPWRA) was then applied to estimate potential outcome mean (POM) and average treatment effect (ATE) by combining the outcome and treatment models.

Results: Breast cancer risks were 0.0072 (95% CI: 0.0055, 0.0089), 0.0051 (95% CI: 0.0008, 0.0095), and 0.0038 (95% CI: 0.002, 0.0056) for non-statin users, hydrophilic, and lipophilic statin users, respectively. The estimated risk differences were -0.0021 (95% CI: -0.0067, 0.0026) and -0.0034 (95% CI: -0.0059, -0.0009) for hydrophilic and lipophilic statins respectively. The number needed to treat for hydrophilic and lipophilic statins were 2.1 (95% CI: -2.6, 6.7) and 3.4 (95% CI: 1.0, 5.9) per 1000 subjected, respectively.

Conclusions: Our results suggested that using lipophilic statin could significantly reduce risk of breast cancer in Thai women.

Statins are Associated With a Reduced Risk of Brain Cancer: A Population-Based Case-Control Study

The aim of this study was to investigate whether statin utilization is associated with brain cancer risk.A population-based case-control study was conducted using nationally representative claims data from the National Health Insurance Bureau in Taiwan. Cases included all patients 50 years and older who received an index diagnosis of brain cancer between 2004 and 2011. Our controls were matched by age, sex, and index date. We estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) using multiple logistic regression.We examined 213 brain cancer cases and 852 controls. The unadjusted ORs for any statin prescription was 0.77 (95% CI = 0.50-1.18) and the adjusted OR was 0.59 (95% CI = 0.37-0.96). Compared with no use of statins, the adjusted ORs were 0.68 (95% CI = 0.38-1.24) for the group having been prescribed with statins with cumulative defined daily dose (DDD) below 144.67 DDDs and 0.50 (95% CI = 0.28-0.97) for the group with the cumulative statin use of 144.67 DDDs or more.The results of this study suggest that statins may reduce the risk of brain cancer.

Statin use and thyroid cancer: a population-based case-control study

OBJECTIVE

Several observational studies raised the possibility that the use of statins may decrease the overall risk of cancer and of specific cancers. This study aimed to evaluate the association of statin use with thyroid cancer based on a population-based data set.

DESIGN

The data for this case-control study were sourced from the Taiwan Longitudinal Health Insurance Database 2000. We included 500 subjects with thyroid cancer as cases and 2500 gender- and age-matched subjects without thyroid cancer as controls. We used a conditional logistic regression to calculate the odds ratio (OR) and its corresponding 95% confidence interval (CI) for having previously used statins between cases and controls.

RESULTS

The OR of prior statin use for cases was 1.39 (95% CI = 1.08-1.78) compared to controls, and thyroid cancer was significantly associated with previous regular statin use (OR = 1.40, 95% CI = 1.05-1.86). However, thyroid cancer was not significantly associated with previous irregular statin use (OR = 1.35; 95% CI = 0.88-2.07). Furthermore, the significant association between thyroid cancer and previous statin use only existed for females (OR: 1.43; 95% CI: 1.07-1.90) but not for males (OR: 1.28; 95% CI: 0.75-2.17).

CONCLUSIONS

We concluded that statin use was associated with thyroid cancer in female patients.

Advances in Preventive Therapy for Estrogen-Receptor-Negative Breast Cancer

Preventing breast cancer is an effective strategy for reducing breast cancer deaths. The purpose of chemoprevention (also termed preventive therapy) is to reduce cancer incidence by use of natural, synthetic, or biological agents. The efficacy of tamoxifen, raloxifene, and exemestane as preventive therapy against estrogen-receptor (ER)-positive breast cancer is well established for women at increased risk for breast cancer. However, because breast cancer is a heterogeneous disease, distinct preventive approaches may be required for effective prevention of each subtype. Current research is, therefore, focused on identifying alternative mechanisms by which biologically active compounds can reduce the risk of all breast cancer subtypes including ER-negative breast cancer. Promising agents are currently being developed for prevention of HER2-positive and triple-negative breast cancer (TNBC) and include inhibitors of the ErbB family receptors, COX-2 inhibitors, metformin, retinoids, statins, poly(ADP-ribose) polymerase inhibitors, and natural compounds. This review focuses on recent progress in research to develop more effective preventive agents, in particular for prevention of ER-negative breast cancer.

Prospective analysis of association between statin use and breast cancer risk in the women's health initiative

BACKGROUND

Statins are a class of cholesterol-lowering drugs that affect many intracellular pathways that may have implications for chemoprevention against cancer. Epidemiologic data on statins and breast cancer are conflicting. We analyzed updated data from the Women's Health Initiative (WHI) to assess the relationship between statins and breast cancer risk.

METHODS

The population included 154,587 postmenopausal women ages 50 to 79 years, with 7,430 pathologically confirmed cases of breast cancer identified over an average of 10.8 (SD, 3.3) years. Information on statins was collected at baseline and years one, three, six, and nine. Self- and interviewer-administered questionnaires were used to collect information on risk factors. Cox proportional hazards regression was used to calculate HRs with 95% confidence intervals (CI) to evaluate the relationship between statin use and cancer risk. Statistical tests were two-sided.

RESULTS

Statins were used by 11,584 (7.5%) women at baseline. The annualized rate of breast cancer was 0.42% among statin users and 0.42% among nonusers. The multivariable adjusted HR of breast cancer for users versus nonusers was 0.94 (95% CI, 0.83-1.06). In the multivariable-adjusted, time-dependent model, the HR for simvastatin was 0.87 (95% CI, 0.71-1.07). There was no significant trend by overall duration of use (P value for trend 0.68). There was no effect of tumor stage, grade, or hormone receptor status.

CONCLUSION

Overall, statins were not associated with breast cancer risk.

IMPACT

Our study is one of the largest prospective observational studies on this topic, and substantially adds to the literature suggesting no relationship between statins and breast cancer risk.

Targeted therapy for breast cancer prevention

With a better understanding of the etiology of breast cancer, molecularly targeted drugs have been developed and are being testing for the treatment and prevention of breast cancer. Targeted drugs that inhibit the estrogen receptor (ER) or estrogen-activated pathways include the selective ER modulators (tamoxifen, raloxifene, and lasofoxifene) and aromatase inhibitors (AIs) (anastrozole, letrozole, and exemestane) have been tested in preclinical and clinical studies. Tamoxifen and raloxifene have been shown to reduce the risk of breast cancer and promising results of AIs in breast cancer trials, suggest that AIs might be even more effective in the prevention of ER-positive breast cancer. However, these agents only prevent ER-positive breast cancer. Therefore, current research is focused on identifying preventive therapies for other forms of breast cancer such as human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancer (TNBC, breast cancer that does express ER, progesterone receptor, or HER2). HER2-positive breast cancers are currently treated with anti-HER2 therapies including trastuzumab and lapatinib, and preclinical and clinical studies are now being conducted to test these drugs for the prevention of HER2-positive breast cancers. Several promising agents currently being tested in cancer prevention trials for the prevention of TNBC include poly(ADP-ribose) polymerase inhibitors, vitamin D, and rexinoids, both of which activate nuclear hormone receptors (the vitamin D and retinoid X receptors). This review discusses currently used breast cancer preventive drugs, and describes the progress of research striving to identify and develop more effective preventive agents for all forms of breast cancer.

Statins and Breast Cancer: Future Directions in Chemoprevention

Given the high incidence, morbidity and mortality associated with breast cancer, developing effective chemopreventive strategies is crucial. Clinicians must carefully identify both populations at risk who would benefit from chemoprevention, and interventions that are effective and safe. Tamoxifen and raloxifene, the two agents approved for breast cancer chemoprevention, and third generation aromatase inhibitors reduce only the incidence of hormone receptor-positive tumors. 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMG-CoAR) inhibitors, or statins, are well tolerated and approved for prevention of cardiovascular disease. In preclinical breast cancer models statins carry potent anti-neoplastic activity. Results from epidemiological and clinical studies, however, are conflicting and have not identified a strong relationship between statin use and reduced breast cancer incidence. These studies have several limitations and were not designed to detect modest effects in high-risk populations. Additional focused epidemiological and translational studies in high-risk populations are needed to justify and guide definitive large prospective trials.

Long-term statin use and risk of ductal and lobular breast cancer among women 55 to 74 years of age

BACKGROUND

Mechanistic studies largely support the chemopreventive potential of statins. However, results of epidemiologic studies investigating statin use and breast cancer risk have been inconsistent and lacked the ability to evaluate long-term statin use.

METHODS

We used data from a population-based case-control study of breast cancer conducted in the Seattle-Puget Sound region to investigate the relationship between long-term statin use and breast cancer risk. Nine hundred sixteen invasive ductal carcinoma (IDC) and 1,068 invasive lobular carcinoma (ILC) cases in patients 55 to 74 years of age diagnosed between 2000 and 2008 were compared with 902 control women. All participants were interviewed in-person and data on hypercholesterolemia and all episodes of lipid-lowering medication use were collected through a structured questionnaire. We assessed the relationship between statin use and IDC and ILC risk using polytomous logistic regression.

RESULTS

Current users of statins for 10 years or longer had a 1.83-fold increased risk of IDC [95% confidence interval (CI): 1.14-2.93] and a 1.97-fold increased risk of ILC (95% CI: 1.25-3.12) compared with never users of statins. Among women diagnosed with hypercholesterolemia, current users of statins for 10 years or longer had more than double the risk of both IDC (OR: 2.04, 95% CI: 1.17-3.57) and ILC (OR: 2.43, 95% CI: 1.40-4.21) compared with never users.

CONCLUSION

In this contemporary population-based case-control study, long-term use of statins was associated with increased risks of both IDC and ILC.

IMPACT

Additional studies with similarly high frequencies of statin use for various durations are needed to confirm this novel finding.

Statin use and the risk of esophageal cancer: a population-based case-control study

OBJECTIVE

The aim of this study was to investigate whether the use of statins was associated with esophageal cancer risk.

METHODS

A population-based case-control study was conducted in Taiwan. Cases consisted of all patients who were aged 50 years and older and had a first-time diagnosis of esophageal cancer for the period between 2004 and 2010. The controls were matched to cases by age, sex and index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using multiple logistic regression.

RESULTS

A total of 197 esophageal cancer cases and 788 controls were examined. The unadjusted ORs for any statin prescription was 0.86 (95% CI = 0.56 - 1.34) and the adjusted OR was 0.96 (95% CI = 0.59 - 1.58). Compared with no use of statins, the adjusted ORs were 0.77 (95% CI = 0.39 - 1.55) for the group having been prescribed statins with cumulative defined daily dose (DDDs) below 115 and 1.16 (95% CI = 0.63 - 2.14) for the group with cumulative statin use of 115 DDDs or more.

CONCLUSIONS

The present data do not provide evidence to support either beneficial or harmful associations between statin use and esophageal cancer risk.

Effects of statins on the prognosis of local and locally advanced renal cell carcinoma following nephrectomy

The anti-angiogenic properties of statins, widely used for the treatment of hyperlipidemia, have recently been reported. The aim of this study was to investigate the effects of use of statins for the management of post-operative recurrence and progression of renal cell carcinoma (RCC). Of 306 patients diagnosed with kidney cancer between January, 2006 and June, 2012, 115 patients who showed no distant metastasis and had undergone radical or partial nephrectomy were selected. These patients were divided into a group that took statins and a group that did not. The effects of statins on the progression and recurrence of renal cancer were retrospectively analyzed. The demographics of the statins group showed that there were more males (P=0.039) and that they were of older age [mean age, 65.24 (±6.82) vs. 58.95 (±12.33) years; P=0.039] and of higher body mass index (BMI) [26.17 (±2.96) vs. 24.24 (±3.35), P=0.017]. Recurrence-free survival in the two groups showed 59.44 and 66.72 months for the statin and non-statin groups, respectively, with no statistically significant difference (P=0.586). Progression-free survival also showed no statistically significant difference between the two groups (P=0.307). Results of the multivariate analysis using Cox's regression model revealed that gender, age and BMI had no significance as prognostic factors for the recurrence and progression of renal cancer (P>0.05). Findings of the present study demonstrated that statins do not have a marked effect on the recurrence and progression of renal cancer. Therefore, further investigation using a larger patient group should be conducted for future statistical analysis.

Statins and colorectal cancer

The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, more commonly referred to as statins, comprise a family of lipid-lowering drugs that are prescribed on a global scale on account of their proven safety and efficacy in reducing mortality from cardiovascular disease. Beyond their potent pharmacologic inhibition of cholesterol biosynthesis, statins appear to have pleiotropic effects, including modulation of cell growth, apoptosis, and inflammation. Through modulation of these pathways, statins have the potential to influence a wide range of disease processes, including cancer. Much attention has focused on the association between statins and colorectal cancer, raising the prospect that these well-tolerated compounds could form the basis of future chemopreventive strategies. Herein, we review the epidemiologic, clinical, and preclinical data relevant to statins and colorectal neoplasia, and discuss the current status and future potential of statins as chemopreventive agents.

Statin use and risk of prostate cancer: a meta-analysis of observational studies

BACKGROUND

Emerging evidence suggests that statins may decrease the risk of cancers. However, available evidence on prostate cancer (PCa) is conflicting. We therefore examined the association between statin use and risk of PCa by conducting a detailed meta-analysis of all observational studies published regarding this subject.

METHODS

Literature search in PubMed database was undertaken through February 2012 looking for observational studies evaluating the association between statin use and risk of PCa. Before meta-analysis, the studies were evaluated for publication bias and heterogeneity. Pooled relative risk (RR) estimates and 95% confidence intervals (CIs) were calculated using random-effects model (DerSimonian and Laird method). Subgroup analyses, sensitivity analysis and cumulative meta-analysis were also performed.

RESULTS

A total of 27 (15 cohort and 12 case-control) studies contributed to the analysis. There was heterogeneity among the studies but no publication bias. Statin use significantly reduced the risk of both total PCa by 7% (RR 0.93, 95% CI 0.87-0.99, p = 0.03) and clinically important advanced PCa by 20% (RR 0.80, 95% CI 0.70-0.90, p<0.001). Long-term statin use did not significantly affect the risk of total PCa (RR 0.94, 95% CI 0.84-1.05, p = 0.31). Stratification by study design did not substantially influence the RR. Furthermore, sensitivity analysis confirmed the stability of results. Cumulative meta-analysis showed a change in trend of reporting risk from positive to negative in statin users between 1993 and 2011.

CONCLUSIONS

Our meta-analysis provides evidence supporting the hypothesis that statins reduce the risk of both total PCa and clinically important advanced PCa. Further research is needed to confirm these findings and to identify the underlying biological mechanisms.

Statin use and risk of breast cancer: a meta-analysis of observational studies

Emerging evidence suggests that statins' may decrease the risk of cancers. However, available evidence on breast cancer is conflicting. We, therefore, examined the association between statin use and risk of breast cancer by conducting a detailed meta-analysis of all observational studies published regarding this subject. PubMed database and bibliographies of retrieved articles were searched for epidemiological studies published up to January 2012, investigating the relationship between statin use and breast cancer. Before meta-analysis, the studies were evaluated for publication bias and heterogeneity. Combined relative risk (RR) and 95 % confidence interval (CI) were calculated using a random-effects model (DerSimonian and Laird method). Subgroup analyses, sensitivity analysis, and cumulative meta-analysis were also performed. A total of 24 (13 cohort and 11 case-control) studies involving more than 2.4 million participants, including 76,759 breast cancer cases contributed to this analysis. We found no evidence of publication bias and evidence of heterogeneity among the studies. Statin use and long-term statin use did not significantly affect breast cancer risk (RR = 0.99, 95 % CI = 0.94, 1.04 and RR = 1.03, 95 % CI = 0.96, 1.11, respectively). When the analysis was stratified into subgroups, there was no evidence that study design substantially influenced the effect estimate. Sensitivity analysis confirmed the stability of our results. Cumulative meta-analysis showed a change in trend of reporting risk of breast cancer from positive to negative in statin users between 1993 and 2011. Our meta-analysis findings do not support the hypothesis that statins' have a protective effect against breast cancer. More randomized clinical trials and observational studies are needed to confirm this association with underlying biological mechanisms in the future.

Statin use and the risk of gallstone disease: a population-based case-control study

OBJECTIVE

The aim of this study was to investigate whether the use of statins was associated with a decreased risk of gallstone disease.

METHODS

We conducted a population-based case-control study in Taiwan. Cases consisted of all patients who were aged 50 years and older and had a first-time diagnosis of gallstone disease or cholecystectomy for the period between 2005 and 2009. The controls were matched to cases by age, sex and index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using multiple logistic regression.

RESULTS

We examined 1014 gallstone disease cases and 1014 controls. The unadjusted ORs for any statin prescription was 1.06 (95% CI 0.86 to 1.29), and the adjusted OR was 1.14 (95% CI 0.90 to 1.43). Compared with no use of statins, the adjusted ORs were 1.05 (95% CI 0.72 to 1.54) for the group having been prescribed statins with cumulative defined daily doses (DDDs) below 41.53, 1.12 (95% CI 0.84 to 1.50) for the group with cumulative dose between 41.54 and 334.81 DDD, and 1.30 (95% CI 0.86 to 1.95) for the group with cumulative statin use of 334.81 DDDs or more.

CONCLUSIONS

This study does not provide support for a beneficial association between usage of statin and gallstone disease.

Statin use and the risk of colorectal cancer: A population-based case-control study

AIM: To investigate whether the use of statins is associated with colorectal cancer risk.

METHODS: We conducted a population-based case-control study in Taiwan. Data were retrospectively collected from the Taiwan National Health Insurance Research Database. Cases consisted of all patients who were aged 50 years and older and had a first-time diagnosis of colorectal cancer between the period 2005 and 2008. The controls were matched to cases by age, sex, and index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multiple logistic regression.

RESULTS: We examined 1156 colorectal cancer cases and 4624 controls. The unadjusted ORs for any statin prescription was 1.10 (95% CI = 0.94-1.30) and the adjusted OR was 1.09 (95% CI = 0.91-1.30). When statin use was categorized by cumulative dose, the adjusted ORs were 0.99 (95% CI = 0.78-1.27) for the group with cumulative statin use below 105 defined daily doses (DDDs); 1.07 (95% CI = 0.78-1.49) for the group with cumulative statin use between 106 and 298.66 DDDs; and 1.30 (95% CI = 0.96-1.75) for the group with cumulative statin use of 298.66 DDDs or more compared with nonusers.

CONCLUSION: This study does not provide support for a protective effect of statins against colorectal cancer.

Statin use and fatal prostate cancer: a matched case-control study

BACKGROUND

Statins are some of the most commonly prescribed medications in medical practice, and prostate cancer is the most common malignancy among men. Although there has been no consistent evidence that statins affect cancer incidence, including prostate cancer, several reports suggest they may decrease the rate of advanced prostate cancer. However, no study to date has specifically examined statin use and prostate cancer mortality. The authors conducted this population-based case-control investigation to examine this association.

METHODS

This was a matched case-control study. Cases were residents of New Jersey ages 55 to 79 years who died from prostate cancer between 1997 and 2000. The cases were matched individually to population-based controls by 5-year age group and race. Medication data were obtained identically for cases and controls from blinded medical chart review. Conditional logistic regression was used to adjust for confounders.

RESULTS

In total, 718 cases were identified, and cooperation was obtained from 77% of their spouses (N = 553). After a review of medical records, 387 men were eligible, and 380 were matched to a control. The unadjusted odds ratio was 0.49 (95% confidence interval, 0.34-0.70) and decreased to 0.37 (P < .0001) after adjusting for education, waist size, body mass index, comorbidities, and antihypertensive medication. There was little difference between lipophilic and hydrophilic statins, but more risk reduction was noted for high-potency statins (73%; P < .0001) compared with low-potency statins (31%; P = .32).

CONCLUSIONS

Statin use was associated with substantial protection against prostate cancer death, adding to the epidemiologic evidence for an inhibitory effect on prostate cancer.

Statins increase the risk of prostate cancer: a population-based case-control study

BACKGROUND

Experimental studies have shown that statins have potential protective effects against cancer. The aim of this study was to investigate whether the use of statins was associated with prostate cancer risk.

METHODS

We conducted a population-based case-control study in Taiwan. Data were retrospectively collected from the Taiwan National health Insurance Research Database. Cases consisted of all patients who were aged 50 years and older and had a first-time diagnosis of prostate cancer for the period between 2005 and 2008. The controls were matched to cases by age, sex, and index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using multiple logistic regression.

RESULTS

We examined 388 prostate cancer cases and 1,552 controls. We found that ever-use of any statin was associated with a significant increase in prostate cancer risk (OR = 1.55, 95%CI = 1.09-2.19). Compared with no use of statins, the adjusted ORs (95%CI) were 1.17 (0.60-2.28) for the group with cumulative dose ≤29.44 DDD, 1.59 (1.02-2.48) for the group with cumulative dose between 29.44 DDD and 321.33 DDD, and 1.86 (1.03-3.37) for the group with the highest cumulative dose (≥321.33 DDD). Also, there was a significant trend toward increasing prostate cancer risk with increasing cumulative dose (χ(2) for linear trend = 7.23, P = 0.007).

CONCLUSIONS

The results of this case-control study suggest that statins may increase the risk of prostate cancer.

Statins are associated with a reduced risk of gastric cancer: a population-based case-control study

OBJECTIVES

Experimental studies have shown that statins have potential protective effects against cancer. The aim of this study was to investigate whether the use of statins was associated with gastric cancer risk.

METHODS

We conducted a population-based case-control study in Taiwan. Data were retrospectively collected from the Taiwan National health Insurance Research Database. Cases consisted of all patients who were aged ≥50 years and had a first-time diagnosis of gastric cancer for the period between 2005 and 2008. The controls were matched to cases by age, sex, and index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using multiple logistic regression.

RESULTS

We examined 337 gastric cancer cases and 1,348 controls. We found that ever-use of any statin was associated with a significant decrease in gastric cancer risk (OR=0.68, 95% CI=0.49-0.95). Compared with no use of statins, the adjusted ORs were 0.90 (95% CI=0.60-1.36) for the group having been prescribed statins with cumulative defined daily doses (DDDs) <134.25 and 0.49 (95% CI=0.30-0.79) for the group with cumulative statin use of ≥134.25 DDDs. Also, there was a significant trend toward decreasing gastric cancer risk with increasing cumulative dose (χ(2) for linear trend=7.42, P=0.006).

CONCLUSIONS

The results of this study are the first to suggest that statins may reduce the risk of gastric cancer.

Pharmacological actions of statins: a critical appraisal in the management of cancer

Statins, among the most commonly prescribed drugs worldwide, are cholesterol-lowering agents used to manage and prevent cardiovascular and coronary heart diseases. Recently, a multifaceted action in different physiological and pathological conditions has been also proposed for statins, beyond anti-inflammation and neuroprotection. Statins have been shown to act through cholesterol-dependent and -independent mechanisms and are able to affect several tissue functions and modulate specific signal transduction pathways that could account for statin pleiotropic effects. Typically, statins are prescribed in middle-aged or elderly patients in a therapeutic regimen covering a long life span during which metabolic processes, aging, and concomitant novel diseases, including cancer, could occur. In this context, safety, toxicity, interaction with other drugs, and the state of health have to be taken into account in subjects treated with statins. Some evidence has shown a dichotomous effect of statins with either cancer-inhibiting or -promoting effects. To date, clinical trials failed to demonstrate a reduced cancer occurrence in statin users and no sufficient data are available to define the long-term effects of statin use over a period of 10 years. Moreover, results from clinical trials performed to evaluate the therapeutic efficacy of statins in cancer did not suggest statin use as chemotherapeutic or adjuvant agents. Here, we reviewed the pharmacology of the statins, providing a comprehensive update of the current knowledge of their effects on tissues, biological processes, and pathological conditions, and we dissected the disappointing evidence on the possible future use of statin-based drugs in cancer therapy.

Cardiovascular medications and risk of cancer

Cardiovascular disease and cancer are 2 of the leading causes of death globally. Certain cardiovascular medications have been linked to an increased risk for cancer. Although individual reviews of specific classes of cardiovascular medications have been published previously, a more complete review of several classes has not been performed. The aim of this review is to evaluate the associations of various cardiovascular agents with the risk for developing cancer and provide guidance for clinicians. A comprehensive search of published research was conducted using MEDLINE from 1994 to 2011. Three trials demonstrated an increased risk for cancer using angiotensin II receptor blockers. Additionally, risk for cancer was shown in a number of trials that included the use of angiotensin II receptor blockers in combination with angiotensin-converting enzyme inhibitors. Five trials suggested that diuretics increased the risk for specific cancers, especially in women and those who had been using diuretics for >4 years. Statins and ezetimibe, in contrast, did not show this increased risk. Prasugrel was shown to be associated with an increased risk for cancer in 1 study. It appears that the use of certain cardiovascular medications is associated with an increased risk for cancer. In conclusion, clinicians need to balance the risks and benefits of the use of these agents and provide the appropriate therapy on an individual basis.

Statin use and the risk of pancreatic cancer: a population-based case-control study

OBJECTIVES

The aim of this study was to investigate whether the use of statins was associated with pancreatic cancer risk.

METHODS

We conducted a population-based case-control study in Taiwan. Data were retrospectively collected from the Taiwan National health Insurance Research Database. Cases consisted of all patients who were 50 years or older and had a first-time diagnosis of pancreatic cancer for the period between 2003 and 2008. The control subjects were matched to cases by age, sex, and index date. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using multiple logistic regression.

RESULTS

We examined 190 pancreatic cancer cases and 760 control subjects. The unadjusted OR for any statin prescription was 1.07 (95% CI, 0.72-2.06), and the adjusted OR was 0.87 (95% CI, 0.56-1.36). Compared with no use of statins, the adjusted ORs were 1.06 (95% CI, 0.61-1.85) for the group having been prescribed statins with cumulative defined daily doses less than 114.33 and 0.71 (95% CI, 0.39-1.30) for the group with cumulative statin use of 114.33 defined daily doses or more.

CONCLUSIONS

This study does not provide support for a beneficial association between usage of statin and pancreatic cancer.

Statin use and the risk of liver cancer: a population-based case–control study

OBJECTIVES

Experimental studies have shown that statins have potential protective effects against cancer. The aim of this study was to investigate whether the use of statins was associated with liver cancer risk.

METHODS

We conducted a population-based case–control study in Taiwan. Data were retrospectively collected from the Taiwan National Health Insurance Research Database. Cases consisted of all patients who were aged ≥50 years and had a first-time diagnosis of liver cancer for the period between 2005 and 2008. Controls were pair matched to cases by age, sex, and index date. Adjusted odds ratios (ORs) and 95% CIs (95% confidence intervals) were estimated using multiple logistic regression.

RESULTS

We examined 1,166 liver cancer cases and 1,166 controls. Compared with the group with no use of statins, the adjusted ORs were 0.62 (95% CI=0.42-0.91) for the group having been prescribed statins below 215.4 defined daily dose (DDD) and 0.63 (95% CI=0.37-1.06) for the group with cumulative statin use ≥215.4 DDD. The ORs for the group with cumulative statin use ≥215.4 DDD were not statistically significant, but this may be due to the relatively small number of subjects.

CONCLUSIONS

The results of this study suggest that statins may reduce the risk of liver cancer.

Chinese red yeast rice inhibition of prostate tumor growth in SCID mice

Prostate cancer is a slowly developing but very common cancer in males that may be amenable to preventive strategies that are not toxic. Chinese red yeast rice (RYR), a food herb made by fermenting Monascus purpureus Went yeast on white rice, contains a mixture of eight different monacolins that inhibit cholesterogenesis in addition to red pigments with antioxidant properties. Monacolin K is identical to lovastatin (LV), but LV unlike RYR can be used in individuals intolerant to statins due to muscle pain. Both LV and RYR inhibit de novo cholesterogenesis, which is critical to the growth of tumor cells. Long-term use of statin drugs has been associated with a reduced risk of prostate cancer. We have previously shown that RYR inhibited androgen-dependent and androgen receptor-overexpressing androgen-independent prostate cancer cell proliferation in vitro. This study was designed to determine whether RYR and LV inhibit prostate tumor growth in SCID mice. RYR significantly reduced tumor volumes of androgen-dependent and androgen-independent prostate xenograft tumors compared with animals receiving vehicle alone (P < 0.05). Inhibition by RYR was greater than that observed with LV at the dose found in RYR, showing that other compounds in RYR contributed to the antiproliferative effect. There was a significant correlation of tumor volume to serum cholesterol (P < 0.001). RYR decreased gene expression of androgen synthesizing enzymes (HSD3B2, AKR1C3, and SRD5A1) in both type of tumors (P < 0.05). Clinical studies of RYR for prostate cancer prevention in the increasing population of men undergoing active surveillance should be considered.

Minimal detection bias in the inverse association between statin drug use and advanced prostate cancer risk: a simulation study

BACKGROUND

Prospective studies support that statins may protect against advanced prostate cancer. Detection bias arising from higher PSA screening rates among statin users vs. non-users could produce an inverse association for advanced disease. Thus, we conducted simulations to assess whether this source of bias is explanatory.

METHODS

3000 datasets with 100,000 men without prostate cancer were simulated for populations with high (65%) or low (15%) PSA screening. We investigated three scenarios: RR(true)=1.0, 0.75, and 0.5 for statins and advanced disease (1.0 for localized). We set the statin prevalence to 10% and varied the percentage of users who were PSA screened (0-100%). We assumed an annual total prostate cancer incidence of 1%, with risk in screened men twice that of unscreened men, and an advanced stage at diagnosis in 20% and 40% of cases in screened and unscreened men, respectively.

RESULTS

As PSA screening and statin use became more coincident, the RR(observed) for local and total prostate cancer was biased upward from the RR(true) of 1.0, especially when the prevalence of PSA screening was low. However, in all simulated scenarios, there was little downward bias for advanced disease (e.g., if RR(true)=1.0 and 70% of statin users and either 65% or 15% of the population overall was PSA screened, then RR(observed)=0.98 for both).

CONCLUSIONS

Given our assumptions, this simulation suggests that this source of detection bias is unlikely to explain the reported inverse association between statins and advanced prostate cancer, but may explain the positive association for total prostate cancer that has been reported in some studies.

Statin use and cancer risk: a comprehensive review

IMPORTANCE OF THE FIELD

HMG-CoA inhibitors (statins), a class of drugs that reduce cholesterol, are used to manage and prevent coronary heart disease. They are among the most commonly prescribed drugs worldwide. Contrary to early concerns over the carcinogenicity of statins, a growing body of evidence suggests statins may in fact have a chemopreventive potential against cancer.

AREAS COVERED IN THIS REVIEW

In this paper, we review evidence on the association between statin use and cancer risk. Specifically, we report on clinical trials and observational studies that measured all cancer or site-specific cancers of the breast, colorectal, lung, prostate and reproductive organs associated with statin use.

WHAT THE READER WILL GAIN

An understanding of the evidence, including strengths and limitations, to support an association between statins and cancer. Information on the current state of the field and future directions are also discussed.

TAKE HOME MESSAGE

Few strong or consistent associations between statins and cancer incidence overall or for any of the sites reviewed were detected. Data for any effects of statins on cancer prognosis and secondary prevention are lacking; with the exception of consistent evidence that statins are associated with reduced risk of advanced/aggressive prostate cancer. Statins appear safe in relation to cancer risk but any chemopreventive effect in humans remains to be established and should not be recommended outside the context of clinical trials. It is encouraging that numerous trials are ongoing. The prospect of reducing the incidence and burden of some of the most prevalent cancers with safe, affordable and tolerable medication that already reduces the risk of the leading cause of death and cardiovascular disease warrants further exploration in clinical trials and observational studies of prognosis and survival.

The association between statin use and the diagnosis of prostate cancer in a population based cohort

PURPOSE

The effect of statin medication use on the risk of prostate cancer is unknown.

MATERIALS AND METHODS

We examined data from a longitudinal, population based cohort of 2,447 men between 40 and 79 years old who were followed from 1990 to 2007. Information on statin use was self-reported and obtained by biennial questionnaires. A randomly selected subset of men (634, 26%) completed biennial urological examinations that included serum prostate specific antigen measurements. Information on prostate biopsy and prostate cancer was obtained through review of community medical records.

RESULTS

Of 634 statin users 38 (6%) were diagnosed with prostate cancer vs 186 (10%) of 1,813 nonstatin users. Statin use was associated with a decreased risk of undergoing prostate biopsy (HR 0.31; 95% CI 0.24, 0.40), receiving a prostate cancer diagnosis (HR 0.36; 95% CI 0.25, 0.53) and receiving a high grade (Gleason 7 or greater) prostate cancer diagnosis (HR 0.25; 95% CI 0.11, 0.58). Statin use was also associated with a nonsignificantly decreased risk of exceeding a prostate specific antigen threshold of 4.0 ng/ml (HR 0.63; 95% CI 0.35, 1.13). In addition, a longer duration of statin use was associated with a lower risk of these outcomes (all tests for trend p <0.05).

CONCLUSIONS

Statin use is associated with a decreased risk of prostate cancer diagnosis. This association may be explained by decreased detection or cancer prevention.

Diverse effects of statins on angiogenesis: new therapeutic avenues

Angiogenesis is an important process for a variety of physiologic and pathologic conditions. Different angiogenic modulating targets are under extensive investigation both experimentally and clinically. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) are the first-line agents used in hypercholesterolemia. They are also characterized by having other benefits apart from their lipid-lowering effects. Among these pleiotropic effects are the pro- and antiangiogenic properties of statins. The pleiotropic effects of statins and how they modulate new blood vessel formation are discussed in this review. The currently available data from both animal and human studies regarding the effects of statins on angiogenesis in ischemic heart disease, stroke, ocular diseases, and cancer are also reviewed. Statins are safe, orally available agents that may acquire novel therapeutic indications through their angiogenic modulating effects.

Statin Use and Cancer Risk: An Epidemiologic Review

While the beneficial effects of hydroxy-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) on cardiovascular disease are well established, much uncertainty remains about their effects on cancer. The statins inhibit the rate-limiting step in the mevalonate pathway, leading to reduced levels of cholesterol and other molecules of importance for critical cellular processes. A growing body of preclinical data indicates that statins may have antineoplastic properties, but some studies raise the possibility that statins may possess a carcinogenic potential. Clinical and observational studies of the association between statin use and cancer have been inconclusive with regard to any chemopreventive or therapeutic effect, but they do provide reassuring evidence that statins do not appear to be carcinogenic. The reasons for the varying results are unclear but they may relate to methodological issues. Additional studies, including Phase II randomized trials and epidemiological studies with accurate measures of statin use and comprehensive control for confounding factors, are needed to determine the potentially beneficially effects of statins on cancer development and progression.