Systematic Review and Meta-analysis: Use of Statins Is Associated with a Reduced Incidence of Oesophageal Adenocarcinoma

Statins in Cancer Prevention and Therapy

Statins, a class of HMG-CoA reductase inhibitors best known for their cholesterol-reducing and cardiovascular protective activity, have also demonstrated promise in cancer prevention and treatment. This review focuses on their potential applications in head and neck cancer (HNC), a common malignancy for which established treatment often fails despite incurring debilitating adverse effects. Preclinical and clinical studies have suggested that statins may enhance HNC sensitivity to radiation and other conventional therapies while protecting normal tissue, but the underlying mechanisms remain poorly defined, likely involving both cholesterol-dependent and -independent effects on diverse cancer-related pathways. This review brings together recent discoveries concerning the anticancer activity of statins relevant to HNC, highlighting their anti-inflammatory activity and impacts on DNA-damage response. We also explore molecular targets and mechanisms and discuss the potential to integrate statins into conventional HNC treatment regimens to improve patient outcomes.

Relation of Statin Use with Esophageal Cancer

The present study evaluated the association of long-term statin use with the diagnosis and mortality of esophageal cancer in a Korean population. The Korean National Health Insurance Service-Health Screening Cohort from 2002 to 2019 was enrolled. Esophageal cancer patients were matched with control participants for demographic variables. The statin prescription histories were collected and grouped into <180 days, 180 to 545 days, and >545 days of duration. Propensity score overlap weighting was applied to minimize the bias between the esophageal cancer and control groups. The odds ratios (ORs) of the duration of statin use for esophageal cancer were analyzed using propensity score overlap weighted multivariable logistic regression analysis. The esophageal cancer group was classified as dead and surviving patients, and the ORs of the duration of statin use for the mortality of esophageal cancer were analyzed in an identical manner. Secondary analyses were conducted according to comorbid factors. Patients with esophageal cancer did not show lower odds for the duration of statin prescription in the overall study population (OR = 1.30, 95% CI = 1.03-1.65, p = 0.027 for 180 to 545 days and OR = 1.29, 95% CI = 1.08-1.55, p = 0.006 for >545 days). Subgroups of nonsmokers, past and current smokers, alcohol consumption ≥ 1 time a week, SBP < 140 mmHg and DBP < 90 mmHg, fasting blood glucose ≥ 100 mg/dL, total cholesterol ≥ 200 mg/dL, CCI score = 0, and nondyslipidemia history demonstrated low odds for the duration of statin prescription. Both types of statins, hydrophilic and lipophilic statins, were not related to a lower rate of esophageal cancer. The mortality of esophageal cancer was not associated with the duration of statin prescription. A subgroup with total cholesterol ≥ 200 mg/dL showed lower odds of statin prescription for mortality of esophageal cancer. The duration of statin prescription was not related to a lower rate or mortality of esophageal cancer in the adult Korean population.

Analysis of Barrett's Esophagus and Its Risk Factors: A Cross-Sectional Study of 10,122 Subjects at a Japanese Health Examination Center

INTRODUCTION

Helicobacter pylori eradication is expected to significantly change the prevalence of Barrett's esophagus (BE). However, few reports on this relationship exist. We analyzed the risk factors of BE using the current consensus on length of BE considering H. pylori infection status.

METHODS

We analyzed 10,122 individuals (5,962 men; mean age = 52.9 ± 9.9 years) who had undergone esophagogastroduodenoscopy as part of a medical checkup. Correlations among factors including H. pylori infectious status, endoscopic findings, and BE ≥1 cm were analyzed.

RESULTS

Prevalence of BE, long-segment BE, and esophageal adenocarcinoma was 22.5%, 0.014%, and 0%, respectively. Logistic regression analysis showed that the risk factors for BE were hiatal hernia (odds ratio [OR]: 2.89 [2.59-3.24]), female sex (OR: 0.52 [0.46-0.59]), social drinking (OR:0.77 [0.68-0.87]), H. pylori eradication therapy (OR: 1.34 [1.19-1.51]), proton pump inhibitor (PPI) use (OR: 1.52 [1.18-1.96]), bile reflux (OR: 1.18 [1.04-1.33]), age ≥50 years (OR: 1.13 [1.02-1.26]), and nonsteroidal anti-inflammatory drug (NSAID) use (OR: 1.29 [1.02-1.62]). Although reflux esophagitis (RE) was more common in H. pylori-negative patients (17.2%) than in those after H. pylori eradication therapy (11.8%, p < 0.00001), the latter was correlated with BE, disputing RE as a strong risk factor for BE. Therefore, we conducted a subgroup analysis; most of the risk factors except for PPI use (p = 0.75), H2-receptor antagonist use (p = 0.078), and atrophic gastritis absence (p = 0.72) were positively correlated with BE after H. pylori eradication therapy compared with H. pylori-negative status.

CONCLUSIONS

H. pylori eradication, bile reflux, PPI use, and NSAID use were risk factors for BE along with hiatal hernia, male sex, and older age.

Simvastatin Inhibits Histologic Changes Associated with Gastroduodenal Reflux in a Murine Model

BACKGROUND

Observational studies demonstrate a protective effect of statins on the development and progression of esophageal adenocarcinoma. The role of statins in the prevention of reflux-induced esophageal changes remains unknown.

AIMS

Using a mixed gastroduodenal reflux mouse model, we hypothesized that oral administration of simvastatin would attenuate reflux-induced mucosal changes of the distal esophagus.

METHODS

Human Barrett's (CPB) and esophageal adenocarcinoma (FLO1 and OE19) cells were treated with simvastatin. Cell proliferation and apoptosis were evaluated using the MTS proliferation and annexin V apoptosis assays, respectively. A reflux mouse model was generated by performing a side-to-side anastomosis between the gastroesophageal junction and first portion of the duodenum (duodeno-gastroesophageal anastomosis, DGEA). DGEA mice were fed a standard or simvastatin-containing diet following surgery. Mice were euthanized 6 weeks post-operatively.

RESULTS

Simvastatin significantly decreased proliferation and increased apoptosis in all cell lines. Compared to control animals, mice undergoing DGEA who were fed a standard diet demonstrated a fourfold increase in mucosal thickness and significant increase in proliferating cells (p < 0.0001). DGEA mice fed a simvastatin-containing diet had an attenuated response to reflux, with a significant reduction in mucosal hyperplasia and proliferation (p < 0.0001). DGEA mice fed a simvastatin-containing diet demonstrated significant upregulation of procaspase-3 (p = 0.009) and cleaved caspase-3 (p = 0.034) in the distal esophagus.

CONCLUSIONS

We demonstrate for the first time a reduction in reflux-induced histologic changes of the distal esophagus following oral administration of simvastatin in vivo. These findings identify simvastatin as a potential preventative agent to inhibit the development and progression of reflux-induced esophageal injury.

Targeting Strategies for Aberrant Lipid Metabolism Reprogramming and the Immune Microenvironment in Esophageal Cancer: A Review

Esophageal cancer is of high importance to occurrence, development, and treatment resistance. As evidenced by recent studies, pathways (e.g., Wnt/β-catenin, AMPK, and Hippo) are critical to the proliferation, differentiation, and self-renewal of esophageal cancer. In addition, the above pathways play a certain role in regulating esophageal cancer and act as potential therapeutic targets. Over the past few years, the function of lipid metabolism in controlling tumor cells and immune cells has aroused extensive attention. It has been reported that there are intricate interactions between lipid metabolism reprogramming between immune and esophageal cancer cells, whereas molecular mechanisms should be studied in depth. Immune cells have been commonly recognized as a vital player in the esophageal cancer microenvironment, having complex crosstalk with cancer cells. It is increasingly evidenced that the function of immune cells in the tumor microenvironment (TME) is significantly correlated with abnormal lipid metabolism. In this review, the latest findings in lipid metabolism reprogramming in TME are summarized, and the above findings are linked to esophageal cancer progression. Aberrant lipid metabolism and associated signaling pathways are likely to serve as a novel strategy to treat esophageal cancer through lipid metabolism reprogramming.

Effects of the Prior Use of Statins on Head and Neck Cancer Risk: A Hospital-Based Case-Control Study

Mechanisms related to the potential beneficial effects of statins on cancer are mainly related to the inhibition of the mevalonate pathway. The purpose of this study was to assess the association between prior use of statins and the risk of head and neck cancer. A hospital-based case-control study was conducted at the Dentistry Hospital of the University of Barcelona, including 101 incident cases of head and neck cancer and 101 controls matched to cases by age and sex. Multivariate logistic regression models were used to assess the association between prior statin exposure and head and neck cancer risk. Of the 202 patients included in total, 28.2% had previously received prescriptions for statins. Prior use of statins was found in 25.7% of cases and 30.7% of controls. Exposure to statins was not associated with head and neck cancer risk (OR = 0.72; 95% CI 0.28-1.84; p = 0.49). There was also no time- or dose-dependent association. Similar trends were observed when analyzed by subsites of cancer and recurrence rate. Our findings do not support a beneficial effect of prior statin exposure on head and neck cancer risk. Future research relying on observational data should emulate randomized clinical trials before clinical implications for repurposing drugs can be drawn.

Statin as a therapeutic agent in gastroenterological cancer

Statins inhibit 3-hydroxy-3-methylglutaryl-CoA reductase, the rate-limiting enzyme of the mevalonate pathway, and are widely used as an effective and safe approach handle hypercholesterolemia. The mevalonate pathway is a vital metabolic pathway that uses acetyl-CoA to generate isoprenoids and sterols that are crucial to tumor growth and progression. Multiple studies have indicated that statins improve patient prognosis in various carcinomas. Basic research on the mechanisms underlying the antitumor effects of statins is underway. The development of new anti-cancer drugs is progressing, but increasing medical costs from drug development have become a major obstacle. Readily available, inexpensive and well-tolerated drugs like statins have not yet been successfully repurposed for cancer treatment. Identifying the cancer patients that may benefit from statins is key to improved patient treatment. This review summarizes recent advances in statin research in cancer and suggests important considerations for the clinical use of statins to improve outcomes for cancer patients.

Evidence-based clinical practice guidelines for gastroesophageal reflux disease 2021

In Japan, with the increasing prevalence of gastroesophageal reflux disease (GERD) and growing public interest, the Japanese Society of Gastroenterology issued Evidence-based Clinical Practice Guidelines for GERD (1st edition) in 2009 and a revised 2nd edition in 2015. A number of studies on GERD were subsequently conducted in Japan and abroad, and vonoprazan, a potassium-competitive acid blocker (P-CAB), became available for the first time in Japan in February 2015. The revised 3rd edition (Japanese edition), which incorporates new findings and information, was published in April 2021. These guidelines are summarized herein, particularly sections related to the treatment of GERD. The important clinical issues addressed in the present revision are (i) the introduction of treatment algorithms that classify GERD into reflux esophagitis and non-erosive reflux disease, (ii) the clarification of treatment algorithms based on to the severity of reflux esophagitis, and (iii) the positioning of vonoprazan in the treatment for GERD. The present guidelines propose vonoprazan as the initial/maintenance treatment for severe reflux esophagitis. They also recommend vonoprazan or PPI as an initial treatment for mild reflux esophagitis and recommended PPI and proposed vonoprazan as maintenance treatment. These updated guidelines offer the best clinical strategies for GERD patients in Japan and hope that they will be of global use for the diagnosis and treatment for GERD.

Proton pump inhibitors may reduce the risk of high-grade dysplasia and/or esophageal adenocarcinoma in Barrett's esophagus: a systematic review and meta-analysis

BACKGROUND

Barrett's esophagus (BE) is an important risk factor for high-grade dysplasia (HGD) and/or esophageal adenocarcinoma (EAC). The effect of proton pump inhibitors (PPIs) on the chemoprevention of HGD and/or EAC arising from BE remains controversial.

RESEARCH DESIGN AND METHODS

PubMed, EMBASE, and Cochrane Library databases were systematically searched. Risk ratios (RRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were pooled by a random-effect model. Heterogeneity and its potential source were assessed.

RESULTS

Fifteen studies with 26,291 BE patients were included. Meta-analysis of eight cohort studies showed that PPIs can significantly reduce the risk of HGD and/or EAC in BE patients (RR = 0.46; P < 0.001), but meta-analysis of six case-control studies showed no significant benefit of PPIs (OR = 0.64; P = 0.334). Heterogeneity was significant among both cohort and case-control studies, which might be attributed to the information sources of PPIs. There was no significant protective effect of high-dose PPIs on HGD and/or EAC in one RCT (RR = 0.84; P = 0.21), meta-analysis of two cohort studies (RR = 0.61; P = 0.28), or meta-analysis of two case-control studies (OR = 0.32; P = 0.08).

CONCLUSIONS

Chemoprevention of HGD and/or EAC by PPIs may be considered in BE patients. However, there might not be further preventive effect of high-dose PPIs.

The Effect of Statins in Cancer Risk Reduction in Patients on Dialysis: A Population-Based Case-Control Study

Simple Summary

The lifetime risk of several cancers is elevated in patients receiving dialysis following kidney failure compared with the general population. Using a large dataset available in Taiwan, we conducted a nationwide population-based cohort study to delineate the relationship between statin use and cancer risk in patients on dialysis. Our study provides an association that statins reduce the risk of malignancy in patients on dialysis, especially with a longer treatment duration, and irrespective of the type of statin prescription. The use of statins in patients on dialysis was associated with significantly lower incidences in developing respiratory, soft tissue and connective tissue, breast, gynecological, prostate, central nervous system, and lymphatic and hematopoietic cancer.

Abstract

Background: To realize whether statins reduce the risk of cancer in susceptible dialysis populations, this study analyzed the relationship between statin use and cancer risk in patients on dialysis. Methods: Patients having a history of chronic kidney disease with hemodialysis or peritoneal dialysis and receiving statin prescriptions or not were enrolled. The main outcome was cancer diagnosis. This study used univariate and multivariate Cox regression analyses. Results: In total, 4236 individuals in the statin group and 8472 individuals in the statin nonuser group were included in the study. Multivariate Cox regression analysis revealed that statin users are significantly less likely to develop cancer than statin nonusers (adjusted hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.78–0.90). Subgroup analyses revealed that statin cumulative defined daily doses >365 were associated with a significantly decreased risk of cancer incidence (adjusted HR 0.59, 95% CI 0.45–0.87), and statin users have a reduced risk of respiratory, soft tissue and connective tissue, breast, gynecological, prostate, central nervous system, and lymphatic and hematopoietic cancer than nonusers. Conclusions: Our population-based cohort study provides an association that statins reduce the risk of malignancy in patients on dialysis, especially with a longer treatment duration, and certain types of cancer.

Is metformin use associated with a reduced risk of oesophageal cancer? A systematic review and meta-analysis

OBJECTIVES

Studies on the association between metformin use and the risk of oesophageal cancer (OC) have generated controversial findings. This updated meta-analysis was conducted to reassess the effects of metformin on OC.

METHODS

A comprehensive search strategy was conducted to select relevant studies from origination to February 2021. Heterogeneity was evaluated through the Q test and I² statistics. HRs and 95% CIs were pooled through either random-effect or fixed-effect models. Meta-regression, subgroup analyses, sensitivity analysis and publication bias diagnosis were also performed.

RESULTS

Seven studies with 5 426 343 subjects were included. Metformin use was associated with reduced risk of OC (HR=0.69, 95% CI 0.54 to 0.87, p<0.001). Sensitivity analysis suggested that the results were relatively stable.

CONCLUSION

Metformin is associated with a reduced risk of OC. More well-designed studies are still needed to further elaborate on these associations.

PROSPERO REGISTRATION NUMBER

CRD42021237127.

Chemoprevention in Barrett's esophagus and esophageal adenocarcinoma

There has been a dramatic increase in the incidence of Barrett's esophagus and esophageal adenocarcinoma over the past several decades with a continued rise expected in the future. Several strategies have been developed for screening and surveillance of patients with Barrett's esophagus and endoscopic treatment of Barrett's associated dysplasia and early esophageal cancer; however, they have not made a substantial impact on the incidence of cancer. Herein, chemoprevention becomes an attractive idea for reducing the incidence of cancer in Barrett's patients. Several agents appear promising in preclinical and observational studies but very few have been evaluated in randomized controlled trials. Strongest evidence to date is available for proton-pump inhibitors and Aspirin that have been evaluated in a large randomized controlled trial. Other agents such as statins, metformin, ursodeoxycholic acid, and dietary supplements have insufficient evidence for chemoprevention in Barrett's patients.

Targeting the Mevalonate Pathway for Treating Esophageal Cancer

PURPOSE

To asseess whether the mevalonate pathway can be targeted in managing patients with esophageal cancer.

METHODS

This a narrative review of peer-revieweed publications indexed in MedLine PubMed. The search was conducted by using "Esophageal cancer", "Mevalonate pahtway", "Statins", and "Translational research."

RESULTS

The mevalonate pathway is an important metabolic pathway that is involved in various cellular functions. Its downstream products are essential for cell-signaling, cell membrane integrity, protein synthesis, and cellular respiration. Statins, a class of medications that are best known as lipid-lowering drugs, inhibit the rate-limiting enzyme of this pathway. Many studies have shown that a variety of cancerous cells have a dysregulated mevalonate pathway. Esophageal cancer is a malignancy that has a poor prognosis, which is mainly due to patients presenting once the cancer is in the advances stages. Chemotherapy has been the mainstay for treating esophageal cancer. However, these agents are not consistently effective and fail to differentiate between the different subtypes of esophageal cancers. Identifying other classes of drugs which could possess anti esophageal cancer properties is appealing.

CONCLUSION

There is a growing body of literature that has shown the anti-cancer properties of statins in the setting of various malignancies. Herein, we summarize the current literature as it pertains to how the mevalonate pathway can be targeted by statins for potentially treating esophageal cancer.

Targeting nutrient metabolism with FDA-approved drugs for cancer chemoprevention: Drugs and mechanisms

Proliferating cancer cells exhibit metabolic alterations and specific nutritional needs for adapting to their rapid growth. These changes include using aerobic glycolysis, lipid metabolic disorder, and irregular protein degradation. It may be useful to target metabolic abnormalities for cancer chemoprevention. Epidemiological and mechanism-related studies have indicated that many FDA-approved anti-metabolic drugs decrease tumor risk, inhibit tumor growth, or enhance the effect of chemotherapeutic drugs. Drugs targeting nutrient metabolism have fewer side effects with long-term use compared to chemotherapeutic drugs. The characteristics of these drugs make them promising candidates for cancer chemoprevention. Here, we summarize recent discoveries of the chemo-preventive effects of drugs targeting nutrient metabolic pathways and discuss future applications and challenges. Understanding the effects and mechanisms of anti-metabolic drugs in cancer has important implications for exploring strategies for cancer chemoprevention.

Leptin activates Akt in oesophageal cancer cells via multiple atorvastatin-sensitive small GTPases

Obesity is a risk factor for Barrett’s oesophagus and oesophageal adenocarcinoma. Adipose tissue secretes the hormone leptin. Leptin is a growth factor for several cell types, including Barrett’s cells and oesophageal adenocarcinoma cells. Statins are associated with reduced rates of Barrett’s oesophagus and oesophageal cancer and exhibit anti-cancer effects in vitro. The mechanisms of these effects are not fully established. We have examined the effects of leptin and the lipid-soluble statin, atorvastatin, on signalling via monomeric GTP-binding proteins and Akt. Proliferation and apoptosis were assessed in OE33 cells. Akt activity was quantified by cell-based ELISA and in vitro kinase assay. Specific small-molecule inhibitors and a dominant-negative construct were used to reduce Akt activity. Small GTPases were inhibited using transfection of dominant-negative plasmids, prenylation inhibitors and pretreatment with atorvastatin. Leptin stimulated Akt activity and cell proliferation and inhibited camptothecin-induced apoptosis in an Akt-sensitive manner. Leptin induced phosphorylation of Bad and FOXO1 in an Akt-sensitive manner. Leptin activated Ras, Rac, RhoA and cdc42. Transfection of dominant-negative plasmids confirmed that leptin-induced Akt activation required Ras, RhoA cdc42 but not Rac. Atorvastatin inhibited leptin-induced activation of Ras, RhoA, cdc42 and Akt. Co-treatment with mevalonate prevented these effects of atorvastatin. The protein kinase Akt is essential to the growth-promoting and anti-apoptotic effects of leptin in oesophageal adenocarcinoma cells. Akt is activated via Ras-, Rho- and cdc42-dependant pathways. Atorvastatin reduces leptin-induced Akt activation by inhibiting prenylation of small GTPases. This may explain the reduced incidence of oesophageal adenocarcinoma in statin-users.

Do proton pump inhibitors prevent Barrett's esophagus progression to high-grade dysplasia and esophageal adenocarcinoma? An updated meta-analysis

PURPOSE

Previous research on the association between proton pump inhibitor (PPI) use and the risk of progression to high-grade dysplasia (HGD)/esophageal adenocarcinoma (EAC) in Barrett's Esophagus (BE) patients has generated inconsistent findings. This meta-analysis was performed to clarify the association.

METHODS

We performed a comprehensive search strategy to select relevant studies up to September 2020. Heterogeneity was assessed using the I-squared statistic. Odds ratios (OR) and 95% confidence intervals (CI) were calculated through either fixed-effects or random-effects model. Duration-response was also performed to assess the gain effects of different PPI intake duration. Sensitivity analysis, subgroup analyses, and tests for publication bias or other small-study effects were conducted.

RESULTS

Twelve studies with 155,769 subjects were included. The PPI use was associated with the reduced risk of BE progression to HGD/EAC (OR = 0.47, 95% CI = 0.32-0.71). In the duration-response analysis, the estimated OR for decreased risk of HGD/EAC with PPI intake duration of 12 months was 0.81 (95% CI = 0.71-0.91). Sensitivity analysis suggested the results of this meta-analysis were stable. No publication bias was detected.

CONCLUSIONS

PPI use is associated with a decreased risk of HGD/EAC in patients with BE. For further investigation, that more well-designed studies are still needed to elucidate the protective effect of PPI usage on BE patients to prevent HGD/EAC.

Current Status of Chemoprevention in Barrett's Esophagus

Candidates for chemoprevention in Barrett's esophagus have long been suggested and there has been observational data to support many drugs, including statins, hormone replacement therapy, metformin, proton pump inhibitor therapy, and aspirin. Proton pump inhibitor therapy and aspirin are the most promising agents. Data suggest that aspirin and proton pump inhibitor therapy can decrease the risk of neoplastic progression in Barrett's esophagus. Further, the combination of aspirin and proton pump inhibitor therapy decrease all-cause mortality by approximately 33%. Future guideline groups need to evaluate the evidence rigorously, but the combination of proton pump inhibitor therapy and aspirin is promising.

Statins Inhibit Toll-Like Receptor 4-Mediated Growth of Human Esophageal Adenocarcinoma Cells

BACKGROUND

Esophageal adenocarcinoma (EAC) is a lethal malignancy with poor prognosis. Pharmacologic inhibitors of inflammation, such as statins, have been shown to decrease the risk of development and progression of esophageal cancer, but the mechanism of this protection is unclear. The objective of this study was to elucidate the effect of statins on toll-like receptor 4-mediated-proliferation of human EAC cells and identify the mechanism responsible for these observed effects.

METHODS

Human EAC cells (OE33 and FLO1) were treated with simvastatin or atorvastatin for increasing doses and time periods. Toll-like receptor 4 (TLR4) expression was assessed. Cells were pretreated with statin followed by lipopolysaccharide (LPS). Cell proliferation and expression of signaling proteins were evaluated. FLO1 cells were injected into the flank of nude mice. Mice received intraperitoneal injections of simvastatin, atorvastatin, or control solution and tumor volume was measured.

RESULTS

OE33 and FLO1 cells demonstrated decreased TLR4 expression after treatment with simvastatin or atorvastatin for 8 h (P < 0.05). LPS increased proliferation, whereas pretreatment with statin abolished this response (P < 0.05). Statins decreased expression and activation of LPS-induced signaling proteins, including MyD88, TRAF6, Akt, and NF-κB (P < 0.05). Mice receiving daily statin injections demonstrated smaller tumors than control mice (P < 0.001 at day 33).

CONCLUSIONS

Treatment of EAC cells with simvastatin or atorvastatin decreases TLR4-mediated proliferation and in vivo tumor growth. Decreased TLR4 expression and subsequent reduction in MyD88-dependent signaling could be a mechanism by which statins act to reduce tumor growth rates.

Association between statin use and second cancer risk in breast cancer patients: a nationwide population-based cohort study

PURPOSE

Many studies have revealed that statin therapy reduced mortality in cancer patients, especially in breast cancer, but the effect for second cancer was unclear. We, therefore, performed a comparable cohort study to determine the risk of second cancer in breast cancer patients with statin therapy.

METHODS

Using claims data from Taiwan's National Health Insurance Program, this study enrolled newly diagnosed breast cancer patients from 2000 to 2007 with and without statin therapy as the statin (n = 1222) and nonstatin (n = 4888) cohorts, respectively. The nonstatin cohort was propensity score matched by cohort entry year, age, and randomly selected comorbidities. These two cohorts were followed up until the diagnosis of second cancer, death, or the end of 2011. Cox proportional hazard models were used to estimate the hazard ratios.

RESULTS

The statin cohort had a lower incidence rate than the nonstatin cohort for second cancer (7.37 vs. 8.36 per 1000 person-years), although the difference was not significant (adjusted hazard ratio [aHR] 0.90, 95% confidence interval [CI] 0.65-1.26). Compared with the nonstatin cohort, the second cancer risk was significantly higher for patients taking pravastatin (aHR 2.71, 95% CI 1.19-6.19) but lower for those receiving multiple statin treatment (aHR 0.45, 95% CI 0.25-0.81) and combined lipophilic and hydrophilic type of statin (aHR 0.42, 95% CI 0.20-0.89). The risk was lower for patients receiving a cumulative defined daily dose (cDDD) of > 430 (aHR 0.41, 95% CI 0.19-0.86).

CONCLUSION

This study showed that there is little association between statin use and second cancer risk in breast cancer patients.

Association of Common Use Pharmaceuticals in Reducing Risk of Esophageal Adenocarcinoma: A SEER-Medicare Analysis

Barrett's esophagus (BE), a recognized risk factor for esophageal adenocarcinoma (EAC), is routinely managed with proton pump inhibitors (PPIs) when symptomatic. Several lines of evidence suggest that PPIs may prevent malignant transformation. Chronic use of other common drugs, namely, statins nonsteroidal anti-inflammatory drugs (NSAIDs) and metformin, may also interfere with BE carcinogenesis, but confirmatory evidence is lacking. We identified 1,943 EAC cases and 19,430 controls (matched 10:1) between 2007 and 2013 that met our specified inclusion criteria in the SEER-Medicare database. Conditional logistic regression was used to generate odds ratios (OR) and 95% confidence intervals (95% CI). Wald χ² tests were used to assess significance of covariates. Compared with controls, EAC cases had a higher prevalence of BE (26.2%). Use of PPIs, NSAIDs, statins, or metformin reduced the odds of EAC (PPIs: 0.10; 95% CI, 0.09-0.12; NSAIDs: 0.62; 95% CI, 0.51-0.74; statins: 0.15; 95% CI, 0.13-0.17; metformin: 0.76; 95% CI, 0.62-0.93). When stratified by BE, these associations persisted, though no association was found between NSAID use and EAC risk for participants with BE. Dual use of PPIs with NSAIDs or statins, and NSAID, statin, or metformin use alone also showed significant EAC risk reduction among all participants and those without BE. Use of PPIs alone and with NSAIDs, statins, or metformin was associated with reduced risk of EAC; however, a history of BE may diminish drug efficacy. These results indicate that common pharmacologic agents alone or in combination may decrease EAC development.Prevention Relevance: The use of common drugs, such as proton pump inhibitors, statins, non-steroidal anti-inflammatory drugs, or metformin, may reduce one's risk of developing esophageal adenocarcinoma. These results suggest that repurposing agents often used for common chronic conditions may be a new strategy for cancer prevention efforts.

Chemoprevention of esophageal adenocarcinoma

Esophageal adenocarcinoma (EAC) is a major cause of cancer-related death, particularly in Western populations, and is rapidly rising in Asian populations at this time. Virtually all EACs develop from the precursor lesion Barrett's esophagus (BE), which is the most significant risk factor for EAC. However, the rates of progression from BE to EAC are low and patients with BE are asymptomatic. Thus, any strategy for EAC prevention must carry a low risk of harm in order to be clinically useful. Since current EAC-screening and BE-surveillance methods carry some procedural risk and are burdensome, there is an opportunity for chemoprevention, i.e. medications or dietary factors that may prevent BE from progressing to EAC. A variety of candidate chemoprevention therapies have been assessed to date. Proton-pump inhibitors (PPIs) are the best studied and have modest EAC-chemoprevention efficacy in BE patients, with a recent randomized trial showing that high-dose PPI may be more effective than low-dose PPI. Aspirin and other non-steroidal anti-inflammatory drugs have moderate quality observational and randomized-trial evidence for preventing progression of BE to EAC, but their risks for harm have precluded their routine clinical use. Other therapies (statins, metformin, female sex hormones) generally do not have strong evidence to support their use in EAC chemoprevention. Although progress has been made in this field, there is still a need for more effective and safe chemoprevention therapies for EAC.

Attempts to use statins in cancer therapy: An update

Although it could be speculated that almost everything has been said concerning the use of statins in cancer therapy, statins as anticancer drugs have both committed supporters and opponents, for whom the dispute about the legitimacy of statin use in cancer treatment seems never to be clearly resolved; every year more than 300 reports which deepen the knowledge about statins and their influence on cancer cells are published. In this mini-review, we focus on the latest (since 2015) outcomes of cohort studies and meta-analyses indicating statin effectiveness in cancer treatment. We discuss attempts to improve the bioavailability of statins using nanocarriers and review the effectiveness of statins in combined therapies. We also summarise the latest results regarding the development of mechanisms of resistance to statins by cancer cells and, on the other hand, give a few examples where statins could potentially be used to overcome resistance to commonly used chemotherapeutics. Finally, special attention is paid to new reports on the effect of statins on epithelial-mesenchymal transition.

New drugs are not enough‑drug repositioning in oncology: An update

Drug repositioning refers to the concept of discovering novel clinical benefits of drugs that are already known for use treating other diseases. The advantages of this are that several important drug characteristics are already established (including efficacy, pharmacokinetics, pharmacodynamics and toxicity), making the process of research for a putative drug quicker and less costly. Drug repositioning in oncology has received extensive focus. The present review summarizes the most prominent examples of drug repositioning for the treatment of cancer, taking into consideration their primary use, proposed anticancer mechanisms and current development status.

Interactive decision support for esophageal adenocarcinoma screening and surveillance

BACKGROUND

A key barrier to controlling esophageal adenocarcinoma (EAC) is identifying those most likely to benefit from screening and surveillance. We aimed to develop an online educational tool, termed IC-RISC™, for providers and patients to estimate more precisely their absolute risk of developing EAC, interpret this estimate in the context of risk of dying from other causes, and aid in decision-making.

RESULTS

U.S. incidence and mortality data and published relative risk estimates from observational studies and clinical trials were used to calculate absolute risk of EAC over 10 years adjusting for competing risks. These input parameters varied depending on presence of the key precursor, Barrett's esophagus. The open source application works across common devices to gather risk factor data and graphically illustrate estimated risk on a single page. Changes to input data are immediately reflected in the colored graphs. We used the calculator to compare the risk distribution between EAC cases and controls from six population-based studies to gain insight into the discrimination metrics of current practice guidelines for screening, observing that current guidelines sacrifice a significant amount of specificity to identify 78-86% of eventual cases in the US population.

CONCLUSIONS

This educational tool provides a simple and rapid means to graphically communicate risk of EAC in the context of other health risks, facilitates "what-if" scenarios regarding potential preventative actions, and can inform discussions regarding screening, surveillance and treatment options. Its generic architecture lends itself to being easily extended to other cancers with distinct pathways and/or intermediate stages, such as hepatocellular cancer. IC-RISC™ extends current qualitative clinical practice guidelines into a quantitative assessment, which brings the possibility of preventative actions being offered to persons not currently targeted for screening and, conversely, reducing unnecessary procedures in those at low risk. Prospective validation and application to existing well-characterized cohort studies are needed.

Statin use and its potential therapeutic role in esophageal cancer: a systematic review and meta-analysis

Purpose: Statins, known as inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG CoA) reductases, are designed to treat lipid disorders, especially hypercholesterolemia. Apart from their role in preventing heart diseases in patients with high cholesterol, recent evidence suggests that statins have anti-tumor properties. However, studies assessing the association between statin use and esophageal cancer survival outcomes have provided controversial results.

Methods: We conducted a systematic review and meta-analysis focusing on studies evaluating associations between statin use and survival outcomes for esophageal cancer patients.

Results: A total of five cohort studies comprising 24,576 patients were included. Statin use associated with improved overall survival (OS: HR 0.84, 95% CI, 0.75–0.94) and disease-free survival (DFS: HR 0.84, 95% CI, 0.75–0.96) of esophageal cancer patients. The improved survival outcomes were consistent in the esophageal adenocarcinoma subgroup and the esophageal squamous cell cancer subgroup.

Conclusion: A potential therapeutic role of statins in esophageal cancer has been demonstrated in our study, however, the results should be interpreted cautiously and need further confirmation by future studies.

Effect of Statin on Cancer Incidence: An Umbrella Systematic Review and Meta-Analysis

Statins are reported to reduce the risk of cancer, but the results of various published studies have been contradictory. We carried out an umbrella review to provide an overview and understand the strength of evidence, extent of potential biases, and validity of claimed associations between the use of statins and cancer incidence. We comprehensively re-analyzed the data of meta-analyses of randomized controlled trials (RCTs) and observational studies on associations between statin use and cancer incidence. We also assessed the strength of evidence of the re-analyzed outcomes, which were determined from the criteria including statistical significance of the p-value of random-effects, as well as fixed-effects meta-analyses, small study effects, between-study heterogeneity, and a 95% prediction interval. Using a conventional method to assess the significance of meta-analysis (p-value < 0.05), statins had a statistically significant effect on reducing cancer incidence in 10 of 18 types of cancer. When we graded the level of evidence, no cancer type showed convincing evidence, and four cancers (esophageal cancer, hematological cancer, leukemia, and liver cancer) showed suggestive evidence of a preventive effect. There was weak evidence of an association with six cancers, and no significance for the remaining eight cancers. None of the meta-analyses of RCTs on the association of statin and cancer incidence showed a statistical significance. Although there was a preventive effect of statin on cancer incidence in 10 of the 18 cancer types, the evidence supporting the use of statins to reduce cancer incidence was low. Therefore, the associations between statin use and cancer incidence should be carefully considered by clinicians.

Cancer Chemoprevention: Classic and Epigenetic Mechanisms Inhibiting Tumorigenesis. What Have We Learned So Far?

Cancers derive from step by step processes which are differentiated by the progressively accumulated mutations. For some tumors there is a clear progressive advancement from benign lesions to malignancy and for these, preventive screening programs exist. In such cases having those benign lesions are a clear indicator of predisposition while for some other cases, familial patterns of cancer incidence and the identification of mutations are the main indicators of higher risk for having the disease. For patients identified as having predisposition, chemoprevention is a goal and in some cases a possibility. Chemoprevention is the use of any compound, either natural or synthetic that abrogates carcinogenesis or tumor progression, through different mechanisms, some of which have already been described. For example, the classic mechanisms may involve activation of free radical scavenging enzymes, control of chronic inflammation, and downregulation of specific signaling pathways. More recently, epigenetics allowed further understanding of the chemopreventive potential of several agents, such as sulforaphane, green tea derived compounds, resveratrol, isoflavones, and others which we exploit in this review article. Throughout the text we discuss the properties compounds should have in order to be classified as chemopreventive ones and the challenges in translational research in this area, as lots of the success achieved in vitro cannot be translated into the clinical settings, due to several different drawbacks, which include toxicity, cost, dose definition, patient adherence, and regimen of use.

Melatonin May Increase Anticancer Potential of Pleiotropic Drugs

Melatonin (N-acetyl-5-methoxytryptamine) is not only a pineal hormone, but also an ubiquitary molecule present in plants and part of our diet. Numerous preclinical and some clinical reports pointed to its multiple beneficial effects including oncostatic properties, and as such, it has become one of the most aspiring goals in cancer prevention/therapy. A link between cancer and inflammation and/or metabolic disorders has been well established and the therapy of these conditions with so-called pleiotropic drugs, which include non-steroidal anti-inflammatory drugs, statins and peroral antidiabetics, modulates a cancer risk too. Adjuvant therapy with melatonin may improve the oncostatic potential of these drugs. Results from preclinical studies are limited though support this hypothesis, which, however, remains to be verified by further research.

Tree nut, peanut, and peanut butter consumption and the risk of gastric and esophageal cancer subtypes: the Netherlands Cohort Study

BACKGROUND

Nut consumption has been associated with reduced cancer-related mortality. However, it is unclear whether nut consumption also reduces the risk of esophageal and gastric cancer subtypes. We prospectively investigated the relationship of tree nut, peanut, and peanut butter intake with risk of esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), gastric cardia adenocarcinoma (GCA), and gastric non-cardia adenocarcinoma (GNCA) in the Netherlands Cohort Study.

METHODS

In 1986, 120,852 males and females, aged 55-69 years, completed a baseline questionnaire on diet and cancer risk factors. After 20.3 years of follow-up, 133 ESCC, 200 EAC, 191 GCA, and 586 GNCA cases, and 3,720 subcohort members were available for multivariable Cox regression analyses, using a case-cohort approach.

RESULTS

Increased total nut consumption was significantly associated with a decreased risk of ESCC and GNCA [HRs (95% CIs) for 10 + g/day vs. nonconsumers = 0.54 (0.30-0.96) and 0.73 (0.55-0.97), respectively], but not with EAC and GCA risk. Similar trends were observed for tree nut and peanut intake, which were mostly nonsignificant. For peanut butter intake, no significant associations were found. When excluding the first four years of follow-up to reduce the possible influence of reversed causation, the relation between nut consumption and ESCC risk attenuated, but remained inverse.

CONCLUSIONS

Our findings suggest that increased tree nut and peanut consumption is inversely associated with GNCA risk and possibly with ESCC risk, but not with the risk of the other esophageal and gastric cancer subtypes.