Microarray and biochemical analysis of lovastatin-induced apoptosis of squamous cell carcinomas

Big data approach in the field of gastric and colorectal cancer research

Big data is characterized by three attributes: volume, variety,, and velocity. In healthcare setting, big data refers to vast dataset that is electronically stored and managed in an automated manner and has the potential to enhance human health and healthcare system. In this review, gastric cancer (GC) and postcolonoscopy colorectal cancer (PCCRC) will be used to illustrate application of big data approach in the field of gastrointestinal cancer research. Helicobacter pylori (HP) eradication only reduces GC risk by 46% due to preexisting precancerous lesions. Apart from endoscopy surveillance, identifying medications that modify GC risk is another strategy. Population-based cohort studies showed that long-term use of proton pump inhibitors (PPIs) associated with higher GC risk after HP eradication, while aspirin and statins associated with lower risk. While diabetes mellitus conferred 73% higher GC risk, metformin use associated with 51% lower risk, effect of which was independent of glycemic control. Nonetheless, nonsteroidal anti-inflammatory drugs (NA-NSAIDs) are not associated with lower GC risk. CRC can still occur after initial colonoscopy in which no cancer was detected (i.e. PCCRC). Between 2005 and 2013, the rate of interval-type PCCRC-3y (defined as CRC diagnosed between 6 and 36 months of index colonoscopy which was negative for CRC) was 7.9% in Hong Kong, with >80% being distal cancers and higher cancer-specific mortality compared with detected CRC. Certain clinical and endoscopy-related factors were associated with PCCRC-3 risk. Medications shown to have chemopreventive effects on PCCRC include statins, NA-NSAIDs, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers.

Association between statin use and the prognosis of hepatocellular carcinoma after resection: a nationwide cohort study

Background

The majority of patients with hepatocellular carcinoma (HCC) following hepatic resection experience tumor recurrence. Statin use is associated with a reduced risk of HCC development; however, the association between statin use and the prognosis of HCC after resection remains unclear. We aimed to investigate the effect of statin use on the prognosis after hepatic resection among patients with HCC.

Methods

A nationwide cohort study was performed with data from the National Health Insurance Service Database in Korea. Among 65,101 HCC patients who underwent hepatic resection between January 2002 and December 2017, we included 21,470 patients. For validation, a hospital-based cohort of 3366 patients with very early or early-stage HCC who received curative-intent hepatic resection between January 2010 and December 2018 was analyzed. Recurrence-free survival (RFS) and overall survival (OS) was compared between statin users and non-users.

Findings

Among the nationwide cohort of 21,470 patients, 2399 (11.2%) used statins and 19,071 (88.8%) did not. Among the hospital cohort of 3366 patients, 363 (10.8%) used statins and 3003 (89.2%) did not. In the propensity score-matched nationwide cohort, statin users had better RFS (hazard ratio [HR], 0.60; 95% confidence interval [CI], 0.56-0.64; P < 0.001) and OS (HR, 0.49; 95% CI, 0.45-0.53; P < 0.001), with a duration-response relationship. In the propensity score-matched validation hospital cohort, statin treatment was significantly associated with better RFS (HR, 0.73; 95% CI, 0.59-0.90; P = 0.003) and OS (HR, 0.48; 95% CI, 0.32-0.72; P < 0.001). The beneficial effects of statins were more prominent in non-cirrhotics, tumors sized ≥3 cm, tumors with microscopic vascular invasion, or early HCC recurrence (<2 years after resection).

Interpretation

Statin use was associated with a better prognosis in a population-based cohort of patients with HCC after hepatic resection, which was further validated in a large hospital-based cohort.

Funding

Asan Institute for Life Sciences and Corporate Relations; Korean Association for the Study of the Liver.

The Influence of Statin Use on Chemotherapeutic Efficacy in Studies of Mouse Models: A Systematic Review

BACKGROUND/AIM

Using statins as antitumor agents is an approach to cancer therapy that has been explored extensively in specific cancer types. Reframing the query to how a statin interacts with the treatment regimen instead might provide new insight. Given that cell-cycle regulation influences tumorigenesis, it is possible that the cell-cycle phase which a given chemotherapy acts on influences the synergistic effects with adjuvant statin use. In this review, we outline the effect of statins in combination with chemotherapeutic drugs in in vivo animal model studies based on the class of chemotherapy and its relation to the cell cycle.

MATERIALS AND METHODS

This systematic review was conducted using the Preferred Reporting Items for Systematic reviews and Meta-Analyses for Protocols 2015 with 23 articles deemed eligible to be included.

RESULTS

Our review suggests that statins influence the success of chemotherapy treatments. Furthermore, enhanced efficacy was demonstrated with chemotherapeutic drugs that act at every phase of the cell cycle.

CONCLUSION

This type of compilation departs from the norm of describing statin influence on named cancer subtypes and instead catalogs how statins interact with categorical chemotherapy agents which might be beneficial for broader therapeutic decision-making across cancer subtypes, possibly contributing to pharmaceutical development, and thereby helping to maximize patient outcomes.

Statin Medication Improves Five-Year Survival Rates in Patients with Head and Neck Cancer: A Retrospective Case-Control Study of about 100,000 Patients

INTRODUCTION

The overall survival among head and neck cancer patients is still low, even in a time of new therapy regimes. Regarding cancer patients' survival, statin use has already proven to be associated with favorable survival outcomes. Our objective was to investigate the influence of statin medication on the overall survival of head and neck cancer patients.

METHODS

Retrospective clinical data of patients diagnosed with head and neck cancer (International Classification of Diseases codes: C00-C14) were retrieved from a real-world evidence database. The initial cohort was divided into patients with statin medication, who were assigned to building cohort I, and subjects without statin medication, who were assigned to cohort II, both matched by age, gender, and risk factors (nicotine and alcohol abuse/dependence). Subsequently, Kaplan-Meier and risk analyses were performed, and odds and hazard ratios were calculated.

RESULTS

After matching, each cohort contained 48,626 patients (cohort I = females: 15,409; (31.7%), males 33,212 (68.3%); mean age ± standard deviation (SD) at diagnosis 66.3 ± 11.4 years; cohort II = females: 15,432; (31.7%), males 33,187 (68.2%); mean age ± standard deviation (SD) at diagnosis 66.4 ± 11.5 years). Five-year survival was found to be significantly higher for cohort I, with 75.19%, respectively 70.48% for cohort II. These findings were correlated significantly with a risk of death of 15.9% (cohort I) and 17.2% (cohort II); the odds ratio was 0.91 (95% CI: 0.881-0.942) and the hazard ratio 0.80 (0.777-0.827).

CONCLUSIONS

The results indicate that the five-year survival of head and neck cancer patients is significantly improved by statin medication. As this study was conducted retrospectively, our data must be interpreted with caution, especially since other potential influencing factors and the initial tumor stage were not available.

Perspectives of lipid metabolism reprogramming in head and neck squamous cell carcinoma: An overview

Recent studies showed that lipid metabolism reprogramming contributes to tumorigenicity and malignancy by interfering energy production, membrane formation, and signal transduction in cancers. HNSCCs are highly reliant on aerobic glycolysis and glutamine metabolism. However, the mechanisms underlying lipid metabolism reprogramming in HNSCCs remains obscure. The present review summarizes and discusses the “vital” cellular signaling roles of the lipid metabolism reprogramming in HNSCCs. We also address the differences between HNSCCs regions caused by anatomical heterogeneity. We enumerate these recent findings into our current understanding of lipid metabolism reprogramming in HNSCCs and introduce the new and exciting therapeutic implications of targeting the lipid metabolism.

Chemopreventive Effect of Metformin on Gastric Cancer Development

Although Helicobacterpylori infection is the most important causative factor for gastric cancer (GC), H. pylori eradication alone does not completely eliminate the GC risk. In addition to H. pylori eradication, other risk factors for GC should be identified and targeted. Diabetes mellitus (DM) confers a 20% increased risk of GC, which could be mediated via several biological mechanisms including the stimulation of cell proliferation via hyperinsulinemia and increased insulin-growth factor production, the promotion of angiogenesis, and DNA damage. With a current global prevalence of 9.3% and a predicted rise to 10.2% by 2030, DM could contribute substantially to the burden of GC cases worldwide. Emerging evidence showed that metformin possesses chemopreventive effects via both direct (e.g., adenosine monophosphate-activated protein kinase activation and subsequent inhibition of the mammalian target of rapamycin pathway) and indirect (e.g., modulation of the interaction between tumor cells and their microenvironment and gut microbiota) pathways. A recent meta-analysis of observational studies showed that metformin use was associated with 24% lower GC risk. However, many available observational studies related to metformin effects suffered from biases including the failure to adjust for the H. pylori infection status and serial glycemic control and time-related biases. Future prospective studies addressing these pitfalls are needed.

Using genetic variants to evaluate the causal effect of cholesterol lowering on head and neck cancer risk: A Mendelian randomization study

Head and neck squamous cell carcinoma (HNSCC), which includes cancers of the oral cavity and oropharynx, is a cause of substantial global morbidity and mortality. Strategies to reduce disease burden include discovery of novel therapies and repurposing of existing drugs. Statins are commonly prescribed for lowering circulating cholesterol by inhibiting HMG-CoA reductase (HMGCR). Results from some observational studies suggest that statin use may reduce HNSCC risk. We appraised the relationship of genetically-proxied cholesterol-lowering drug targets and other circulating lipid traits with oral (OC) and oropharyngeal (OPC) cancer risk using two-sample Mendelian randomization (MR). For the primary analysis, germline genetic variants in HMGCR, NPC1L1, CETP, PCSK9 and LDLR were used to proxy the effect of low-density lipoprotein cholesterol (LDL-C) lowering therapies. In secondary analyses, variants were used to proxy circulating levels of other lipid traits in a genome-wide association study (GWAS) meta-analysis of 188,578 individuals. Both primary and secondary analyses aimed to estimate the downstream causal effect of cholesterol lowering therapies on OC and OPC risk. The second sample for MR was taken from a GWAS of 6,034 OC and OPC cases and 6,585 controls (GAME-ON). Analyses were replicated in UK Biobank, using 839 OC and OPC cases and 372,016 controls and the results of the GAME-ON and UK Biobank analyses combined in a fixed-effects meta-analysis. We found limited evidence of a causal effect of genetically-proxied LDL-C lowering using HMGCR, NPC1L1, CETP or other circulating lipid traits on either OC or OPC risk. Genetically-proxied PCSK9 inhibition equivalent to a 1 mmol/L (38.7 mg/dL) reduction in LDL-C was associated with an increased risk of OC and OPC combined (OR 1.8 95%CI 1.2, 2.8, p = 9.31 x10-05), with good concordance between GAME-ON and UK Biobank (I2 = 22%). Effects for PCSK9 appeared stronger in relation to OPC (OR 2.6 95%CI 1.4, 4.9) than OC (OR 1.4 95%CI 0.8, 2.4). LDLR variants, resulting in genetically-proxied reduction in LDL-C equivalent to a 1 mmol/L (38.7 mg/dL), reduced the risk of OC and OPC combined (OR 0.7, 95%CI 0.5, 1.0, p = 0.006). A series of pleiotropy-robust and outlier detection methods showed that pleiotropy did not bias our findings. We found limited evidence for a role of cholesterol-lowering in OC and OPC risk, suggesting previous observational results may have been confounded. There was some evidence that genetically-proxied inhibition of PCSK9 increased risk, while lipid-lowering variants in LDLR, reduced risk of combined OC and OPC. This result suggests that the mechanisms of action of PCSK9 on OC and OPC risk may be independent of its cholesterol lowering effects; however, this was not supported uniformly across all sensitivity analyses and further replication of this finding is required.

Pleiotropic effects of statins: A focus on cancer

The statin drugs ('statins') potently inhibit hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase by competitively blocking the active site of the enzyme. Statins decrease de novo cholesterol biosynthesis and thereby reduce plasma cholesterol levels. Statins exhibit "pleiotropic" properties that are independent of their lipid-lowering effects. For example, preclinical evidence suggests that statins inhibit tumor growth and induce apoptosis in specific cancer cell types. Furthermore, statins show chemo-sensitizing effects by impairing Ras family GTPase signaling. However, whether statins have clinically meaningful anti-cancer effects remains an area of active investigation. Both preclinical and clinical studies on the potential mechanisms of action of statins in several cancers have been reviewed in the literature. Considering the contradictory data on their efficacy, we present an up-to-date summary of the pleiotropic effects of statins in cancer therapy and review their impact on different malignancies. We also discuss the synergistic anti-cancer effects of statins when combined with other more conventional anti-cancer drugs to highlight areas of potential therapeutic development.

[Research Progress on the Relationship between Blood Lipids and Lung Cancer Risk and Prognosis]

近年来，肺癌成为导致癌症相关死亡的主要原因。越来越多证据表明，许多脂类和脂类类似物是肿瘤发生的关键调节因子，吸烟、饮食及肥胖等影响血脂水平的因素可能与癌症的风险相关。目前随着脂质与肿瘤发生过程关系的研究逐渐深入，探索血脂与肺癌风险及预后相关性已成为研究的热点。本文就血脂水平与肺癌发病风险、血脂水平与肺癌患者预后相关性及调整血脂药物与防治肺癌方向的研究进展进行综述。

The effects of statins on dental and oral health: a review of preclinical and clinical studies

The statin family of drugs are safe and effective therapeutic agents for the treatment of arteriosclerotic cardiovascular disease (CVD). Due to a wide range of health benefits in addition to their cholesterol lowering properties, statins have recently attracted significant attention as a new treatment strategy for several conditions, which are not directly related to normalizing a lipid profile and preventing CVD. Statins exert a variety of beneficial effects on different aspects of oral health, which includes their positive effects on bone metabolism, their anti-inflammatory and antioxidant properties, and their potential effects on epithelization and wound healing. Additionally, they possess antimicrobial, antiviral, and fungicidal properties, which makes this class of drugs attractive to the field of periodontal diseases and oral and dental health. However, to the best of our knowledge, there has been no comprehensive study to date, which has investigated the effects of statin drugs on different aspects of dental and oral health. Therefore, the primary objective of this paper was to review the effect of statins on dental and oral health. Results of our extensive review have indicated that statins possess remarkable and promising effects on several aspects of dental and oral health including chronic periodontitis, alveolar bone loss due to either extraction or chronic periodontitis, osseointegration of implants, dental pulp cells, orthodontic tooth movement, and orthodontic relapse, tissue healing (wound/bone healing), salivary gland function, and finally, anti-cancer effects. Hence, statins can be considered as novel, safe, inexpensive, and widely-accessible therapeutic agents to improve different aspects of dental and oral health.

Inverse Association between Statin Use and Stomach Cancer Incidence in Individuals with Hypercholesterolemia, from the 2002-2015 NHIS-HEALS Data

Purpose: To investigate the association between statin use and stomach cancer incidence in individuals with hypercholesterolemia. Materials and methods: To examine the cumulative effect of statins, we defined a statin user as one who used statins during 2002–2003 at baseline. Statin users were further classified into high and low users according to the medication possession rate. Statin non-users consisted of participants who had never used statins during the entire period of 2002–2015, despite having hypercholesterolemia (total cholesterol level ≥250 mg/dL at baseline). Ultimately, 17,737 statin users and 13,412 statin non-users were used in the analysis. We performed survival analyses, considering the diagnosis of stomach cancer as an event of interest. Results: Median follow-up duration was 12.9 years. The cumulative incidence rates of stomach cancer were lowest in high users (1.90% in men and 0.98% in women). Compared to non-users, hazard ratios (95% confidential intervals) for stomach cancer of low users and high users were 0.953 (0.755–1.203) and 0.526 (0.399–0.693) in men and 0.629 (0.457–0.865) and 0.370 (0.256–0.535) in women, respectively, after adjusting for possible confounders. Conclusions: We observed an inverse association between statin use and stomach cancer incidence in participants with hypercholesterolemia.

Cholesterol and beyond - The role of the mevalonate pathway in cancer biology

Cancer is a multifaceted global disease. Transformation of a normal to a malignant cell takes several steps, including somatic mutations, epigenetic alterations, metabolic reprogramming and loss of cell growth control. Recently, the mevalonate pathway has emerged as a crucial regulator of tumor biology and a potential therapeutic target. This pathway controls cholesterol production and posttranslational modifications of Rho-GTPases, both of which are linked to several key steps of tumor progression. Inhibitors of the mevalonate pathway induce pleiotropic antitumor-effects in several human malignancies, identifying the pathway as an attractive candidate for novel therapies. In this review, we will provide an overview about the role and regulation of the mevalonate pathway in certain aspects of cancer initiation and progression and its potential for therapeutic intervention in oncology.

Statins reduce the progression of non-advanced adenomas to colorectal cancer: a postcolonoscopy study in 187 897 patients

BACKGROUND AND AIMS

Postcolonoscopy colorectal cancer (PCCRC) accounts for up to 9% of all CRCs. Statins have been shown to be associated with a lower CRC risk. We aimed to investigate whether PCCRC risk was also lower among statin users.

METHODS

This is a retrospective cohort study using a territory-wide electronic healthcare database in Hong Kong including patients aged 40 years or above who had undergone colonoscopies between 2005 and 2013. Exclusion criteria included prior colorectal cancer (CRC), inflammatory bowel disease, prior colectomy and CRC detected within 6 months of index colonoscopy. We defined statin use as at least 90-day use before index colonoscopy. Medication use was traced up to 5 years before index colonoscopy. PCCRC-3y was defined as cancer diagnosed between 6 and 36 months after index colonoscopy. Sites of CRC were categorised as proximal (proximal to splenic flexure) and distal cancer. The subdistribution HR (SHR) of PCCRC-3y with statin use was derived by propensity score matching based on covariates (including patient factors, concurrent medication use and endoscopy centre's performance).

RESULTS

Of 187 897 eligible subjects, 854 (0.45%) were diagnosed with PCCRC-3y. Statin use was associated with a lower PCCRC-3y risk (SHR: 0.72; 95% CI 0.55 to 0.95; p=0.018). Subgroup analysis shows that SHRs were 0.50 (95% CI 0.28 to 0.91; p=0.022) for proximal and 0.80 (95% CI 0.59 to 1.09; p=0.160) for distal cancer. Older (>60 years) patients, women and those without diabetes mellitus or polyps appeared to benefit more from statins.

CONCLUSIONS

Statins were associated with a lower PCCRC risk, particularly for proximal cancer.

Statin Use After Diagnosis of Hepatocellular Carcinoma Is Associated With Decreased Mortality

BACKGROUND & AIMS

Statin use is associated with a lower risk of developing hepatocellular carcinoma (HCC). However, it is unclear whether postdiagnosis statin use is associated with a reduced risk of death in patients with HCC.

METHODS

We performed a retrospective analysis of data from 15,422 patients with HCC in the Veterans Administration Central Cancer Registry, diagnosed from 2002 through 2016. We identified statin prescriptions that were filled before and after the cancer diagnosis and used time-dependent Cox regression models to calculate adjusted hazard ratios (HRs) and 95% CIs for risk of death. We used a time-varying exposure to avoid immortal time bias, and a 3-month lag (following up patients from 3 months after the cancer diagnosis) to reduce reverse causation. A sensitivity analysis was conducted varying the lag duration between date of cancer diagnosis and start of follow-up evaluation.

RESULTS

Statin use after diagnosis was recorded for 14.9% of patients with HCC. We found that postdiagnosis statin use was associated with a decreased risk of cancer-specific death (adjusted HR, 0.85; 95% CI, 0.77-0.93) and all-cause mortality (HR, 0.89; 95% CI, 0.83-0.95). The magnitudes of these inverse associations were consistent for patients who used high or low doses of statins, and the inverse associations remained across a range of lag periods (from 0 months to 12 months after HCC diagnosis). We found no evidence for effect modification by prediagnosis statin use, or by presentation- or treatment-related factors, and no independent association with prediagnosis statin use.

CONCLUSIONS

In a retrospective analysis of data from veterans with HCC, use of statins (high or low doses) after a diagnosis of HCC was associated with reduced mortality.

Obesity: An emerging driver of head and neck cancer

Obesity has become pandemic and emerged as one of the most critical global health care problems worldwide since last century. Recent studies have demonstrated that there may be a causal link between obesity and higher risks and mortality of cancers, including prostate, breast, colon, and thyroid cancers, head and neck cancer (HNC). This review focuses on the relationship between obesity and HNC, and the molecular mechanism of abnormal lipid metabolism in HNC. Elucidating the mechanism may open up new possibilities for strategies to reduce risk and mortality of HNC in an increasingly obese population.

Statin Use and the Risk of Prostate Cancer in Ischemic Heart Disease Patients in Taiwan

Patients with ischemic heart disease (IHD) are more likely to be diagnosed with prostate cancer. Statins, which are widely used in such patients, are shown to modify the risk of prostate cancer. To clarify the association between statin use and the risk of prostate cancer among patients with higher risk of developing prostate cancer in Taiwan, a cohort of 26,628 men with IHD and aged between 55 and 100 were acquired from the National Health Insurance Research Database and followed over a period of 8 years. The risk of prostate cancer was calculated by time-dependent Cox regression model. Statin use was associated with significantly lower risk of both total and advanced prostate cancer (adjusted hazard ratio (HR): 0.719, 95% confidence interval (CI): 0.570-0.908; adjusted HR: 0.718, 95% CI: 0.530-0.972 respectively). In Taiwan IHD population, the reduction in risk of prostate cancer was observed in statin users as compared with nonusers.

Effect of statin use on oncologic outcomes in head and neck squamous cell carcinoma

BACKGROUND

Preclinical and early-phase clinical studies have suggested an oncoprotective role of statins in head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to determine whether incidental statin use in patients with human papillomavirus (HPV)-negative HNSCC is predictive of improved oncologic outcomes.

METHODS

A retrospective cohort study of 1194 patients from the Ontario Cancer Registry diagnosed with HNSCC from 2007 to 2012 was performed using linked databases from the Institute for Clinical Evaluative Sciences. Overall survival (OS) and disease-specific survival (DSS) were compared between patients taking statins and controls.

RESULTS

Patients with statin exposure demonstrated improved OS (hazard ratio [HR] 0.758; P = .0011; 95% confidence interval [CI] 0.642-0.896), and DSS (HR 0.693; P = .0040; 95% CI 0.539-0.889) compared with those not on statins at the time of diagnosis.

CONCLUSION

Incidental statin use at the time of diagnosis of HPV-negative squamous cell carcinoma (SCC) of the larynx, hypopharynx, and nasopharynx demonstrated improved OS and DSS.

Risk of gastric cancer development after eradication of Helicobacter pylori

Helicobacter pylori (H. pylori) infection is the most important risk factor for gastric cancer (GC) development through the Correa’s gastric carcinogenesis cascade. However, H. pylori eradication alone does not eliminate GC, as pre-neoplastic lesions (atrophic gastritis, intestinal metaplasia and dysplasia) may have already developed in some patients. It is therefore necessary to identify patients at high-risk for gastric cancer after H. pylori eradication to streamline the management plan. If the patients have not undergone endoscopy with histologic assessment, the identification of certain clinical risk factors and non-invasive testing (serum pepsinogen) can predict the risk of atrophic gastritis. For those with suspected atrophic gastritis, further risk stratification by endoscopy with histologic assessment according to validated histologic staging systems would be advisable. Patients with higher stages may require long-term endoscopic surveillance. Apart from secondary prevention to reduce deaths by diagnosing GC at an early stage, identifying medications that could potentially modify the GC risk would be desirable. The potential roles of a number of medications have been suggested by various studies, including proton pump inhibitors (PPIs), aspirin, statins and metformin. However, there are currently no randomized clinical trials to address the impact of these medications on GC risk after H. pylori eradication. In addition, most of these studies failed to adjust for the effect of concurrent medications on GC risk. Recently, large population-based retrospective cohort studies have shown that PPIs were associated with an increased GC risk after H. pylori eradication, while aspirin was associated with a lower risk. The roles of other agents in reducing GC risk after H. pylori eradication remain to be determined.

Long-term statin use in patients with lung cancer and dyslipidemia reduces the risk of death

Background

Clinical studies have obtained inconsistent results of statin use on cancer outcomes. This study investigated the association between statin use and lung cancer mortality.

Results

The use of statin decreased mortality (hazard ratio = 0.91; 95% confidence interval: 0.86–0.96; P < .01). The patients with a high cumulative defined daily dose of statin use before lung cancer diagnosis exhibited a low risk of mortality.

Materials and Methods

We conducted a population-based case-control study of patients with dyslipidemia. Among them, 6270 had used statins for at least 3 months before lung cancer diagnosis, and 6270 had never used statins.

Conclusions

We found that statin use can reduce lung cancer mortality. A further prospective study is necessary to confirm these findings.

Isoprenoids responsible for protein prenylation modulate the biological effects of statins on pancreatic cancer cells

Background

Statin treatment of hypercholesterolemia is accompanied also with depletion of the mevalonate intermediates, including farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP) necessary for proper function of small GTPases. These include Ras proteins, prevalently mutated in pancreatic cancer. In our study, we evaluated the effect of three key intermediates of the mevalonate pathway on GFP-K-Ras protein localization and the gene expression profile in pancreatic cancer cells after exposure to individual statins.

Methods

These effects were tested on MiaPaCa-2 human pancreatic cancer cells carrying a K-Ras activating mutation (G12C) after exposure to individual statins (20 μM). The effect of statins (atorvastatin, lovastatin, simvastatin, fluvastatin, cerivastatin, rosuvastatin, and pitavastatin) and mevalonate intermediates on GFP-K-Ras protein translocation was analyzed using fluorescence microscopy. The changes in gene expression induced in MiaPaCa-2 cells treated with simvastatin, FPP, GGPP, and their combinations with simvastatin were examined by whole genome DNA microarray analysis.

Results

All tested statins efficiently inhibited K-Ras protein trafficking from cytoplasm to the cell membrane of the MiaPaCa-2 cells. The inhibitory effect of statins on GFP-K-Ras protein trafficking was partially prevented by addition of any of the mevalonate pathway’s intermediates tested. Expressions of genes involved in metabolic and signaling pathways modulated by simvastatin treatment was normalized by the concurrent addition of FPP or GGPP. K-Ras protein trafficking within the pancreatic cancer cells is effectively inhibited by the majority of statins; the inhibition is eliminated by isoprenoid intermediates of the mevalonate pathway.

Conclusions

Our data indicate that the anticancer effects of statins observed in numerous studies to a large extent are mediated through isoprenoid intermediates of the mevalonate pathway, as they influence expression of genes involved in multiple intracellular pathways.

Electronic supplementary material

The online version of this article (10.1186/s12944-017-0641-0) contains supplementary material, which is available to authorized users.

The interplay between cell signalling and the mevalonate pathway in cancer

The mevalonate (MVA) pathway is an essential metabolic pathway that uses acetyl-CoA to produce sterols and isoprenoids that are integral to tumour growth and progression. In recent years, many oncogenic signalling pathways have been shown to increase the activity and/or the expression of MVA pathway enzymes. This Review summarizes recent advances and discusses unique opportunities for immediately targeting this metabolic vulnerability in cancer with agents that have been approved for other therapeutic uses, such as the statin family of drugs, to improve outcomes for cancer patients.

Concomitant Statin Use Has a Favorable Effect on Gemcitabine-Erlotinib Combination Chemotherapy for Advanced Pancreatic Cancer

PURPOSE

Erlotinib-gemcitabine combined chemotherapy is considered as the standard treatment for unresectable pancreatic cancer. This study aimed to determine the clinical factors associated with response to this treatment.

MATERIALS AND METHODS

This retrospective study included 180 patients with unresectable pancreatic cancer who received ≥2 cycles of gemcitabine-erlotinib combination therapy as first-line palliative chemotherapy between 2006 and 2014. "Long-term response" was defined as tumor stabilization after >6 chemotherapy cycles.

RESULTS

The median progression-free survival (PFS) and overall survival (OS) were 3.9 and 8.1 months, respectively. On univariate analysis, liver metastasis (p=0.023) was negatively correlated with long-term response. Locally advanced stage (p=0.017), a history of statin treatment (p=0.01), and carcinoembryonic antigen levels <4.5 (p=0.029) had a favorable effect on long-term response. On multivariate analysis, a history of statin treatment was the only independent favorable factor for long-term response (p=0.017). Prognostic factors for OS and PFS were significantly correlated with liver metastasis (p=0.031 and 0.013, respectively). A history of statin treatment was also significantly associated with OS after adjusting for all potential confounders (hazard ratio, 0.48; 95% confidence interval, 0.26-0.92; p=0.026).

CONCLUSION

These results suggest that statins have a favorable effect on "long-term response" to gemcitabine-erlotinib chemotherapy in unresectable pancreatic cancer patients. Statins may have a chemoadjuvant role in stabilizing long-term tumor growth.

Preoperative statin use is not associated with improvement in survival after glioblastoma surgery

Cohort studies have suggested that the use of statins is associated with decreased risk of glioma formation and mortality. Here, a cohort of patients with glioblastoma multiforme (GBM) was analyzed to further investigate associations between preoperative use of statins and recurrence, and progression free and overall survival. Patients who had surgery for GBM (N=284) were followed up for a median of 18.1months. Seventy-eight patients were taking statins preoperatively while the rest were not. Cox proportional hazards models adjusted for several covariates of interest were applied before and after propensity score matching. Compared with statin users, those not taking the lipid-lowering drugs had similar progression free survival before (hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.70-1.26; p=0.68) and after propensity score matching (HR 0.95, 95% CI 0.67-1.35; p=0.68). Mortality was similar between both groups of patients before (HR 0.94, 95% CI 0.70-1.22; p= 0.73) and after propensity score matching (HR 1.13, 95% CI 0.78-1.64; p=0.49). Age and dexamethasone use were independent prognostic factors of survival. Contrary to previously published evidence, this study could not find an association between preoperative statin use and longer survival in GBM patients. Due to the small number of patients and retrospective nature of the study, further work is needed to understand the role of perioperative statins in GBM patients.

Previous Exposure to Statin May Reduce the Risk of Subsequent Non-Hodgkin Lymphoma: A Nationwide Population-Based Case-Control Study

Background

The purpose of this study was to investigate the association between previous exposure to statins and the risk of non-Hodgkin lymphoma (NHL).

Methods

This nationwide population-based case–control study was conducted using the National Health Insurance Research Database of Taiwan. The NHL group consisted of the patients with a first-time diagnosis of NHL between 2005 and 2008. The cases of the control group were pair-matched to the NHL group according to sex, year of birth and date of NHL diagnosis (index date). The statin administration data from both groups were retrospectively collected from the index date to January 1, 1996. The cumulative defined daily dose (cDDD) was estimated to evaluate the statin exposure. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariate logistic regression.

Results

The study population was composed of 1715 NHL patients and 16942 control subjects. The analysis revealed that previous statin administration was associated with a reduced risk of subsequent NHL with an adjusted OR of 0.52 (95% CI, 0.43–0.62). Additionally, there was a dose-response relationship between statin administration and the risk of NHL. The adjusted ORs were 0.63 (95% CI, 0.46–0.86), 0.58 (95% CI, 0.42–0.79), 0.51 (95% CI, 0.38–0.67), and 0.36 (95% CI, 0.24–0.53) for the subjects with statin administrations of fewer than 28, 28 to 90, 91 to 365, and more than 365 cDDDs, respectively, relative to the subjects without any statin administration.

Conclusions

The results of this study suggest that previous statin administration is associated with a lower risk of subsequent NHL. As statins are widely used medications, the magnitude of the risk reduction may have a substantial influence on public health. Further studies to confirm our findings are warranted.

In vitro Anti-Tumor Effects of Statins on Head and Neck Squamous Cell Carcinoma: A Systematic Review

BACKGROUND

Statins are commonly used against arteriosclerotic disease, but recent retrospective analyses have suggested that statins also prevent cancer. The aim of this systematic review is to verify the vitro anti-tumor effects of statins on head and neck squamous cell carcinoma.

METHODS

Studies were gathered by searching Cochrane, MEDLINE, EMBASE, LILACS, and PubMed, up until May 9, 2015, with no time or language restrictions. Only in vitro studies that discuss the effect of statins on head and neck carcinoma were selected.

RESULTS

Of 153 identified papers, 14 studies met the inclusion criteria. These studies demonstrated that statins had a significant effect on head and neck squamous cell carcinoma cell lines and influenced cell viability, cell cycle, cell death, and protein expression levels involved in pathways of carcinogenesis, which corroborates with the potential in vitro anti-tumor effects. It provides highlights about the biological mechanisms of statins used alone or associated with traditional therapy for cancer.

CONCLUSIONS

Though there are few studies on the topic, currently available evidence suggests that statins shows that preclinical experiments supports the potentiality of statin as an adjuvant agent in chemotherapy and/or radiotherapy approaches routinely used in the management of HNSCC and should undergo further clinical assessment.

Association between statin use and cancer: data mining of a spontaneous reporting database and a claims database

PURPOSE

In recent years, the potential risk of cancer associated with statin use has been a focus of much interest. However, it remains uncertain whether statin therapy is associated with cancer risk. To examine the association between statin use and the risk of cancer, we conducted data mining using the US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) and a large organized database of claims constructed by a database vendor (The Japan Medical Data Center Co., Ltd, Tokyo, Japan [JMDC]).

METHODS

Relevant reports in the FAERS, which included data from the first quarter of 2004 through the end of 2012, were identified and analyzed. The reporting odds ratio (ROR) was used to detect spontaneous report signals and was calculated using the case/non-case method. Additionally, signals were detected via the information component (IC) using the IC025 metric. Furthermore, event sequence symmetry analysis (ESSA) was applied to identify the risk of cancer following treatment with statins over the period January 2005 to July 2013.

RESULTS

In the FAERS database analyses, significant signals for colorectal cancer and pancreatic cancer were found for statins as a class. In the ESSA, significant associations between statin use and colorectal cancer and pancreatic cancer were found, with adjusted sequence ratios (95% confidence intervals) of 1.20 (1.08-1.34) and 1.31 (1.13-1.53), respectively, at an interval of 48 months.

CONCLUSIONS

Multi-methodological approaches using different algorithms and databases suggest that statin use is associated with an increased risk for colorectal cancer and pancreatic cancer.

Statin use and risk of kidney cancer: a meta-analysis of observational studies and randomized trials

AIM

Clinical studies have shown that statin use may modify the risk of kidney cancer. However, these studies yielded different results. To quantify the association between statin use and risk of kidney cancer, we performed a detailed meta-analysis of published studies regarding this subject.

METHODS

A literature search was carried out using MEDLINE, EMBASE and the Cochrane database between January 1966 and October 2012. Prior to performing a meta-analysis, the studies were evaluated for publication bias and heterogeneity. Fixed effect and random effect models were used to estimate summary relative risks (RR) and the corresponding 95% confidence intervals (CIs). Subgroup analyses and sensitivity analysis were also performed.

RESULTS

A total of 12 (two randomized controlled trials, five cohort, and five case-control) studies contributed to the analysis. There was heterogeneity among the studies but no evidence of publication bias. Pooled results indicated a non-significant decrease of total kidney cancer risk among all statin users (RR = 0.92, 95% CI 0.71, 1.19). Long term statin use did not significantly affect the risk of total kidney cancer (RR = 1.01, 95% CI 0.83, 1.22). In our subgroup analyses, the results were not substantially affected by study design, confounder adjustment and gender. Furthermore, sensitivity analysis confirmed the stability of the results.

CONCLUSION

The findings of this meta-analysis suggested that there was no association between statin use and risk of kidney cancer. More studies, especially randomized controlled trials and high quality cohort studies with larger sample size and well controlled confounding factors, are needed to confirm this association in the future.

Statin use is associated with reduced risk of haematological malignancies: evidence from a meta-analysis

Background

Several observational studies have shown that statin use may modify the risk of haematological malignancies. To quantify the association between statin use and risk for haematological malignancies, we performed a detailed meta-analysis of published studies regarding this subject.

Methods

We conducted a systematic search of multiple databases including PubMed, Embase, and Cochrane Library Central database up to July 2013. Fixed-effect and random-effect models were used to estimate summary relative risks (RR) and the corresponding 95% confidence intervals (CIs). Potential sources of heterogeneity were detected by meta-regression. Subgroup analyses and sensitivity analysis were also performed.

Results

A total of 20 eligible studies (ten case-control studies, four cohort studies, and six RCTs) reporting 1,139,584 subjects and 15,297 haematological malignancies cases were included. Meta-analysis showed that statin use was associated with a statistically significant 19% reduction in haematological malignancies incidence (RR = 0.81, 95% CI [0.70, 0.92]). During subgroup analyses, statin use was associated with a significantly reduced risk of haematological malignancies among observational studies (RR = 0.79, 95% CI [0.67, 0.93]), but not among RCTs (RR = 0.92, 95% CI [0.77, 1.09]).

Conclusions

Based on this comprehensive meta-analysis, statin use may have chemopreventive effects against haematological malignancies. More studies, especially definitive, randomized chemoprevention trials are needed to confirm this association.

Statin use and risk of prostate cancer: a Danish population-based case-control study, 1997-2010

PURPOSE

Conflicting evidence has suggested that statins possess chemopreventive properties against prostate cancer (PCa). Therefore, we examined the association between statin use and risk of PCa in a Denmark-based case-control study.

MATERIALS AND METHODS

We identified 42,480 patients diagnosed with incident PCa during 1997-2010 from a national cancer registry. Five age-matched population controls (n=212,400) were selected for each case using risk-set sampling. Statin use from 1996 to the index date was obtained from the National Prescription Registry. Odds ratios (ORs) adjusted for age, comorbidity, non-steroidal anti-inflammatory drug use, and educational level for PCa associated with statin use, were computed using conditional logistic regression. Analyses were stratified by duration of statin use (0-1, 2-4, 5-9, or ≥10 years), stage of PCa (localized or advanced), and type of statin used (lipophilic or hydrophilic).

RESULTS

In total, 7915 patients (19%) and 39,384 controls (19%) redeemed statin prescriptions prior to the index date. Overall, statin users had a 6% lower risk of PCa compared with non-users [adjusted OR (ORa), 0.94; 95% confidence interval (CI), 0.91-0.97]. Risk estimates did not differ substantially by duration or type of statin used. Slightly larger statin use-associated risk reductions were observed for advanced PCa (ORa, 0.90; 95% CI, 0.85-0.96) and with statin use ≥10 years (ORa, 0.78; 95% CI, 0.65-0.95).

CONCLUSION

Statin use was associated with a risk reduction overall (6%) and, specifically with advanced PCa (10%). Differences in diagnostic measures and residual confounding by socioeconomic parameters may have influenced our results.

Randomized double-blinded, placebo-controlled phase II trial of simvastatin and gemcitabine in advanced pancreatic cancer patients

BACKGROUND

Statins have potential antineoplastic properties via arrest of cell-cycle progression and induction of apoptosis. A previous study demonstrated in vitro and in vivo antineoplastic synergism between statins and gemcitabine. The present randomized, double-blinded, phase II trial compared the efficacy and safety of gemcitabine plus simvastatin (GS) with those of gemcitabine plus placebo (GP) in patients with locally advanced and metastatic pancreatic cancer.

METHODS

Patients were randomly assigned to receive a 3-week regimen with GS (gemcitabine 1,000 mg/m(2) on days 1, 8, and 15 plus simvastatin 40 mg once daily) or GP (gemcitabine 1,000 mg/m(2) on days 1, 8, and 15 plus placebo). The primary end point was time to progression (TTP).

RESULTS

Between December 2008 and April 2012, 114 patients were enrolled. The median TTP was not significantly different between the two arms, being 2.4 months (95 % CI 0.7-4.1 months) and 3.6 months (95 % CI 3.1-4.1 months) in the GS and GP arms, respectively (P = 0.903). The overall disease control rate was 39.7 % (95 % CI 12.2-33.8 %) and 57.1 % (95 % CI 19.8-44.2 %) in the GS and GP arms, respectively (P = 0.09). The 1-year expected survival rates were similar (27.7 and 31.7 % in the GS and GP arms, respectively; P = 0.654). Occurrence of grade 3 or 4 adverse events was similar in both arms, and no patients had rhabdomyolysis.

CONCLUSIONS

Adding low-dose simvastatin to gemcitabine in advanced pancreatic cancer does not provide clinical benefit, although it also does not result in increased toxicity. Given the emerging role of statins in overcoming resistance to anti-EGFR treatment, further studies are justified to evaluate the efficacy and safety of combined simvastatin and anti-EGFR agents, such as erlotinib or cetuximab, plus gemcitabine for treating advanced pancreatic cancer.

Statin use and risk of lung cancer: a meta-analysis of observational studies and randomized controlled trials

Clinical studies have shown that statin use may alter the risk of lung cancer. However, these studies yielded different results. To quantify the association between statin use and risk of lung cancer, we performed a detailed meta-analysis. A literature search was carried out using MEDLINE, EMBASE and COCHRANE database between January 1966 and November 2012. Before meta-analysis, between-study heterogeneity and publication bias were assessed using adequate statistical tests. Fixed-effect and random-effect models were used to calculate the pooled relative risks (RR) and corresponding 95% confidence intervals (CIs). Subgroup analyses, sensitivity analysis and cumulative meta-analysis were also performed. A total of 20 (five randomized controlled trials, eight cohorts, and seven case–control) studies contributed to the analysis. Pooled results indicated a non-significant decrease of total lung cancer risk among all statin users (RR = 0.89, 95% CI [0.78, 1.02]). Further, long-term statin use did not significantly decrease the risk of total lung cancer (RR = 0.80, 95% CI [0.39 , 1.64]). In our subgroup analyses, the results were not substantially affected by study design, participant ethnicity, or confounder adjustment. Furthermore, sensitivity analysis confirmed the stability of results. The findings of this meta-analysis suggested that there was no significant association between statin use and risk of lung cancer. More studies, especially randomized controlled trials and high quality cohort studies are warranted to confirm this association.

Deciphering the signaling networks underlying simvastatin-induced apoptosis in human cancer cells: evidence for non-canonical activation of RhoA and Rac1 GTPases

Although statins are known to inhibit proliferation and induce death in a number of cancer cell types, the mechanisms through which downregulation of the mevalonate (MVA) pathway activates death signaling remain poorly understood. Here we set out to unravel the signaling networks downstream of the MVA pathway that mediate the death-inducing activity of simvastatin. Consistent with previous reports, exogenously added geranylgeranylpyrophosphate, but not farnesylpyrophosphate, prevented simvastatin's growth-inhibitory effect, thereby suggesting the involvement of geranylgeranylated proteins such as Rho GTPases in the anticancer activity of simvastatin. Indeed, simvastatin treatment led to increased levels of unprenylated Ras homolog gene family, member A (RhoA), Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division cycle 42 (Cdc42). Intriguingly, instead of inhibiting the functions of Rho GTPases as was expected with loss of prenylation, simvastatin caused a paradoxical increase in the GTP-bound forms of RhoA, Rac1 and Cdc42. Furthermore, simvastatin disrupted the binding of Rho GTPases with the cytosolic inhibitor Rho GDIα, which provides a potential mechanism for GTP loading of the cytosolic Rho GTPases. We also show that the unprenylated RhoA- and Rac1-GTP retained at least part of their functional activities, as evidenced by the increase in intracellular superoxide production and JNK activation in response to simvastatin. Notably, blocking superoxide production attenuated JNK activation as well as cell death induced by simvastatin. Finally, we provide evidence for the involvement of the B-cell lymphoma protein 2 family, Bcl-2-interacting mediator (Bim), in a JNK-dependent manner, in the apoptosis-inducing activity of simvastatin. Taken together, our data highlight the critical role of non-canonical regulation of Rho GTPases and involvement of downstream superoxide-mediated activation of JNK pathway in the anticancer activity of simvastatin, which would have potential clinical implications.

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.

Statins and the risk of lung cancer: a meta-analysis

PURPOSE

Several epidemiologic studies have evaluated the association between statins and lung cancer risk, whereas randomized controlled trials (RCTs) on cardiovascular outcomes provide relevant data as a secondary end point. We conducted a meta-analysis of all relevant studies to examine this association.

METHODS

A systematic literature search up to March 2012 was performed in PubMed database. Study-specific risk estimates were pooled using a random-effects model.

RESULTS

Nineteen studies (5 RCTs and 14 observational studies) involving 38,013 lung cancer cases contributed to the analysis. They were grouped on the basis of study design, and separate meta-analyses were conducted. There was no evidence of an association between statin use and risk of lung cancer either among RCTs (relative risk [RR] 0.91, 95% confidence interval [CI] 0.76-1.09), among cohort studies (RR 0.94, 95% CI 0.82-1.07), or among case-control studies (RR 0.82, 95% CI 0.57-1.16). Low evidence of publication bias was found. However, statistically significant heterogeneity was found among cohort studies and among case-control studies. After excluding the studies contributing most to the heterogeneity, summary estimates were essentially unchanged.

CONCLUSION

The results of our meta-analysis suggest that there is no association between statin use and the risk of lung cancer.

Statin use and risk of bladder cancer: a meta-analysis

PURPOSE

Emerging evidence suggests that statins may decrease the risk of cancers. However, available evidence on bladder cancer is conflicting. To quantify the association between statin use and risk of bladder cancer, we performed a detailed meta-analysis of published studies regarding this subject.

METHODS

A literature search was carried out using MEDLINE, EMBASE, and OVID databases between January 1966 and October 2012. Before meta-analysis, between-study heterogeneity and publication bias were assessed using adequate statistical tests. Fixed- and random-effect models were used to estimate summary relative risks (RR) and the corresponding 95 % confidence intervals (CIs). Potential sources of heterogeneity were detected by meta-regression. Subgroup analyses, sensitivity analysis, and cumulative meta-analysis were also performed.

RESULTS

A total of 13 (three RCTs, five cohort, and five case-control) studies contributed to the analysis. There was heterogeneity among the studies, but no publication bias. Pooled results indicated a nonsignificant increase in total bladder cancer risk among all statin users [RR = 1.07, 95 % CI (0.95, 1.21)]. Long-term statin use did not significantly affect the risk of total bladder cancer [RR = 1.21, 95 % CI (0.92, 1.59)]. In our subgroup analyses, the results were not substantially affected by study design, region, and confounder adjustment. Furthermore, sensitivity analysis confirmed the stability of the results.

CONCLUSIONS

The findings of this meta-analysis suggested that there was no association between statin use and risk of bladder cancer. More studies, especially RCTs, are needed to confirm this association.

Common cancer risk and statins: a population-based case-control study in a Chinese population

OBJECTIVE

To investigate whether the use of statins is associated with common cancer risk.

METHODS

A population-based case-control study was conducted in Taiwan. Cases were defined as all patients who were aged 18 years and older and had received at least two statin prescriptions for use continuously for at least 6 months before a first-time diagnosis of studied cancers between the period of 2000 and 2008. The controls were matched to cases by age, sex, and index date. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by using the Cox proportional hazards model.

RESULTS

A total of 6841 cases and 27,364 matched controls were analyzed. The adjusted hazard ratio for any statin use and cancer at any site were 0.76 (95% 0.654, 0.891). There were a significant reduced risk of gastric cancer (HR: 0.26, 95% CI: 0.107, 0.588), liver cancer (HR: 0.44, 95% CI: 0.279, 0.723) and uterine cancer (HR: 0.44, 95% CI: 0.279, 0.723) associated with any statins.

CONCLUSION

Overall, the statins suggested a significant reduced risk of the most common cancers in a large Chinese population, particularly in gastric, liver, and uterine cancers.

Statins and the Risk of Hepatocellular Carcinoma in Patients With Hepatitis B Virus Infection

Purpose

Statins have potential protective effects against cancers, but no studies have focused on patients with chronic hepatitis B virus (HBV) infection. The purpose of this study was to investigate the association between the use of statins in HBV-infected patients and the risk of hepatocellular carcinoma (HCC).

Patients and Methods

We conducted a population-based cohort study from the Taiwan National Health Insurance Research Database. A total of 33,413 HBV-infected patients were included as the study cohort. Each patient was individually tracked from 1997 to 2008 to identify incident cases of HCC since 1999. Subsequent use of statin, other lipid-lowering agents, aspirin, and angiotensin-converting enzyme inhibitors was identified. Cox proportional hazards regression was used to calculate the hazard ratios (HRs) and 95% CIs for the association between the use of statins and the occurrence of HCC in the HBV-infected cohort.

Results

There were 1,021 HCCs in the HBV cohort during the follow-up period of 328,946 person-years; the overall incidence rate was 310.4 HCCs per 100,000 person-years. There was a dose-response relationship between statin use and the risk of HCC in the HBV cohort. The adjusted HRs were 0.66 (95% CI, 0.44 to 0.99), 0.41 (95% CI, 0.27 to 0.61), and 0.34 (95% CI, 0.18 to 0.67) for statin use of 28 to 90, 91 to 365, and more than 365 cumulative defined daily doses (cDDDs), respectively, relative to no statin use (< 28 cDDDs).

Conclusion

Statin use may reduce the risk for HCC in HBV-infected patients in a dose-dependent manner. Further mechanistic research is needed.

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.

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.

Arecoline stimulated Cyr61 production in human gingival epithelial cells: inhibition by lovastatin

Cyr61 is associated with growth and progression of many types of tumors and is an independent poor prognostic indicator for oral cancer patients. Areca nut (AN) chewing is the most important etiological factor in the pathogenesis of oral cancer in India and many Southeast Asian countries. Yet, the molecular mechanisms involved in the AN-induced oral cancer remain largely unknown. In this study, we show that arecoline, a main alkaloid found in AN, stimulated Cyr61 synthesis in human gingival epithelial S-G cells. Constitutive overexpression of Cyr61 protein in oral epithelial cells during AN chewing may play a role in the pathogenesis of oral cancer. ERK inhibitor PD98059, N-acetyl-L-cysteine, Rho-associated protein kinase (ROCK) selective inhibitor Y-27632 and a geranylgeranyltransferase inhibitor reduced the arecoline-stimulated levels of Cyr61 protein by ∼31%, 47%, 65% and 100%, respectively. Lovastatin also completely inhibited arecoline-induced Cyr61 synthesis and the inhibition is dose-dependent. Decreased of geranylgeranylated proteins could be the mechanism that lovastatin regulates Cyr61 synthesis and lovastatin could serve as a useful agent in controlling AN-induced oral cancer.