Aspirin use and risk for lung cancer: a meta-analysis

Mechanisms Contributing to the Comorbidity of COPD and Lung Cancer

Lung cancer and chronic obstructive pulmonary disease (COPD) often co-occur, and individuals with COPD are at a higher risk of developing lung cancer. While the underlying mechanism for this risk is not well understood, its major contributing factors have been proposed to include genomic, immune, and microenvironment dysregulation. Here, we review the evidence and significant studies that explore the mechanisms underlying the heightened lung cancer risk in people with COPD. Genetic and epigenetic changes, as well as the aberrant expression of non-coding RNAs, predispose the lung epithelium to carcinogenesis by altering the expression of cancer- and immune-related genes. Oxidative stress generated by tobacco smoking plays a role in reducing genomic integrity, promoting epithelial-mesenchymal-transition, and generating a chronic inflammatory environment. This leads to abnormal immune responses that promote cancer development, though not all smokers develop lung cancer. Sex differences in the metabolism of tobacco smoke predispose females to developing COPD and accumulating damage from oxidative stress that poses a risk for the development of lung cancer. Dysregulation of the lung microenvironment and microbiome contributes to chronic inflammation, which is observed in COPD and known to facilitate cancer initiation in various tumor types. Further, there is a need to better characterize and identify the proportion of individuals with COPD who are at a high risk for developing lung cancer. We evaluate possible novel and individualized screening strategies, including biomarkers identified in genetic studies and exhaled breath condensate analysis. We also discuss the use of corticosteroids and statins as chemopreventive agents to prevent lung cancer. It is crucial that we optimize the current methods for the early detection and management of lung cancer and COPD in order to improve the health outcomes for a large affected population.

Targeting cancer-related inflammation with non-steroidal anti-inflammatory drugs: Perspectives in pharmacogenomics

Inflammatory processes are essential for innate immunity and contribute to carcinogenesis in various malignancies, such as colorectal cancer, esophageal cancer and lung cancer. Pharmacotherapies targeting inflammation have the potential to reduce the risk of carcinogenesis and improve therapeutic efficacy of existing anti-cancer treatment. Non-steroidal anti-inflammatory drugs (NSAIDs), comprising a variety of structurally different chemicals that can inhibit cyclooxygenase (COX) enzymes and other COX-independent pathways, are originally used to treat inflammatory diseases, but their preventive and therapeutic potential for cancers have also attracted researchers' attention. Pharmacogenomic variability, including distinct genetic characteristics among different patients, can significantly affect pharmacokinetics and effectiveness of NSAIDs, which might determine the preventive or therapeutic success for cancer patients. Hence, a more comprehensive understanding in pharmacogenomic characteristics of NSAIDs and cancer-related inflammation would provide new insights into this appealing strategy. In this review, the up-to-date advances in clinical and experimental researches targeting cancer-related inflammation with NSAIDs are presented, and the potential of pharmacogenomics are discussed as well.

Aspirin Use and Common Cancer Risk: A Meta-Analysis of Cohort Studies and Randomized Controlled Trials

Background

Whether aspirin use can decrease or increase cancer risk remains controversial. In this study, a meta-analysis of cohort studies and randomized controlled trials (RCTs) were conducted to evaluate the effect of aspirin use on common cancer risk.

Method

Medline and Embase databases were searched to identify relevant studies. Meta-analyses of cohort studies and RCTs were performed to assess the effect of aspirin use on the risk of colorectal, gastric, breast, prostate and lung cancer. Cochran Q test and the I square metric were calculated to detect potential heterogeneity among studies. Subgroup meta-analyses according to exposure categories (frequency and duration) and timing of aspirin use (whether aspirin was used before and after cancer diagnosis) were also performed. A dose-response analysis was carried out to evaluate and quantify the association between aspirin dose and cancer risk.

Results

A total of 88 cohort studies and seven RCTs were included in the final analysis. Meta-analyses of cohort studies revealed that regular aspirin use reduced the risk of colorectal cancer (CRC) (RR=0.85, 95%CI: 0.78-0.92), gastric cancer (RR=0.67, 95%CI: 0.52-0.87), breast cancer (RR=0.93, 95%CI: 0.87-0.99) and prostate cancer (RR=0.92, 95%CI: 0.86-0.98), but showed no association with lung cancer risk. Additionally, meta-analyses of RCTs showed that aspirin use had a protective effect on CRC risk (OR=0.74, 95%CI: 0.56-0.97). When combining evidence from meta-analyses of cohorts and RCTs, consistent evidence was found for the protective effect of aspirin use on CRC risk. Subgroup analysis showed that high frequency aspirin use was associated with increased lung cancer risk (RR=1.05, 95%CI: 1.01-1.09). Dose-response analysis revealed that high-dose aspirin use may increase prostate cancer risk.

Conclusions

This study provides evidence for low-dose aspirin use for the prevention of CRC, but not other common cancers. High frequency or high dose use of aspirin should be prescribed with caution because of their associations with increased lung and prostate cancer risk, respectively. Further studies are warranted to validate these findings and to find the minimum effective dose required for cancer prevention.

Association between the use of aspirin and risk of lung cancer: results from pooled cohorts and Mendelian randomization analyses

PURPOSE

We aimed to elucidate the associations between aspirin use with risk of lung cancer, by conducting a meta-analysis and Mendelian randomization (MR) analyses from published Genome-Wide Association Studies (GWAS).

METHODS

Cohort studies, nested case-control studies, and randomized controlled trials (RCTs) investigating the impact of aspirin exposure and lung cancer incidence were included. Relative risk (RR) and its 95% confidence interval (CI) were evaluated in eligible studies. Subgroup analyses regarding gender, pathologic subtypes and smoking status were also executed. MR analyses were conducted using summary statistics obtained from two large consortia [Neale Lab and International Lung Cancer Consortium (ILCCO)] to assess the possible causal relationship of aspirin on lung cancer incidence.

RESULTS

Sixteen eligible studies involving 1,522,687 patients were included. The combined RR of aspirin use for the incidence of lung cancer was 0.95 (95% confidence interval (CI) 0.91-0.98). In subgroup meta-analyses, a significant protective effect was observed in squamous cell lung cancer (RR = 0.80; 95% CI 0.65-0.98). In terms of gender, the chemopreventive value was only observed among men (RR = 0.87; 95% CI 0.77-0.97). The MR risk analysis suggested a causal effect of aspirin on lung cancer incidence, with evidence of a decreased risk for overall lung cancer (OR = 0.042; 95% CI 0.003-0.564) and squamous cell lung cancer (OR = 0.002; 95% CI 1.21 × 10^-5-0.301).

CONCLUSION

Our study provided evidence for a causal protective effect of aspirin on the risk of lung cancer incidence among men, particularly on the squamous cell lung cancer risk.

Effect of aspirin on PET parameters in primary non-small cell lung cancer and its relationship with prognosis

Background

18 F-FDG is a glucose analogue whose metabolic index SUV can effectively reflect the metabolic level of tumor microenvironment. Aspirin can affect the uptake of 18F-FDG by cancer cells, reducing the SUVmax value of primary tumors, exerting antitumor effect. This study aimed to evaluate the prognostic value of long-term aspirin and the relationship between aspirin intake and PET parameters value of primary tumor in non-small cell lung cancer (NSCLC).

Methods

Eighty-one NSCLC patients were recruited and divided into two groups: aspirin medication group and control group, who underwent surgery and had pathological diagnosis data between January 2012 and December 2016. Clinical characteristics were retrospective analyzed to evaluate the possibility of clinical prognosis, respectively. Kaplan-Meier curves and a Cox proportional hazard model were applied to evaluate the predictors of prognosis.

Results

The PET/CT SUVmax of the primary tumor in the aspirin group was lower than that in the control group (P < 0.05). Compared with the control group, the SUVmax, SUVmean and TLG of the primary tumor in aspirin group were lower, but the MTV value had no significant difference. Cox regression analysis showed that N stage and TNM stage were predictors of the prognosis. There was a significant difference in the use of aspirin in NSCLC patients.

Conclusion

Aspirin can reduce SUVmax, SUVmean and TLG in primary tumor and aspirin can improve the prognosis of patients with NSCLC.

Elevated Platelet Count Appears to Be Causally Associated with Increased Risk of Lung Cancer: A Mendelian Randomization Analysis

BACKGROUND

Platelets are a critical element in coagulation and inflammation, and activated platelets are linked to cancer risk through diverse mechanisms. However, a causal relationship between platelets and risk of lung cancer remains unclear.

METHODS

We performed single and combined multiple instrumental variable Mendelian randomization analysis by an inverse-weighted method, in addition to a series of sensitivity analyses. Summary data for associations between SNPs and platelet count are from a recent publication that included 48,666 Caucasian Europeans, and the International Lung Cancer Consortium and Transdisciplinary Research in Cancer of the Lung data consisting of 29,266 cases and 56,450 controls to analyze associations between candidate SNPs and lung cancer risk.

RESULTS

Multiple instrumental variable analysis incorporating six SNPs showed a 62% increased risk of overall non-small cell lung cancer [NSCLC; OR, 1.62; 95% confidence interval (CI), 1.15-2.27; P = 0.005] and a 200% increased risk for small-cell lung cancer (OR, 3.00; 95% CI, 1.27-7.06; P = 0.01). Results showed only a trending association with NSCLC histologic subtypes, which may be due to insufficient sample size and/or weak effect size. A series of sensitivity analysis retained these findings.

CONCLUSIONS

Our findings suggest a causal relationship between elevated platelet count and increased risk of lung cancer and provide evidence of possible antiplatelet interventions for lung cancer prevention.

IMPACT

These findings provide a better understanding of lung cancer etiology and potential evidence for antiplatelet interventions for lung cancer prevention.

Associations between aspirin use and the risk of cancers: a meta-analysis of observational studies

Background

Epidemiological studies have clarified the potential associations between regular aspirin use and cancers. However, it remains controversial on whether aspirin use decreases the risk of cancers risks. Therefore, we conducted an updated meta-analysis to assess the associations between aspirin use and cancers.

Methods

The PubMed, Embase, and Web of Science databases were systematically searched up to March 2017 to identify relevant studies. Relative risks (RRs) with 95% confidence intervals (CIs) were used to assess the strength of associations.

Results

A total of 218 studies with 309 reports were eligible for this meta-analysis. Aspirin use was associated with a significant decrease in the risk of overall cancer (RR = 0.89, 95% CI: 0.87–0.91), and gastric (RR = 0.75, 95% CI: 0.65–0.86), esophageal (RR = 0.75, 95% CI: 0.62–0.89), colorectal (RR = 0.79, 95% CI: 0.74–0.85), pancreatic (RR = 0.80, 95% CI: 0.68–0.93), ovarian (RR = 0.89, 95% CI: 0.83–0.95), endometrial (RR = 0.92, 95% CI: 0.85–0.99), breast (RR = 0.92, 95% CI: 0.88–0.96), and prostate (RR = 0.94, 95% CI: 0.90–0.99) cancers, as well as small intestine neuroendocrine tumors (RR = 0.17, 95% CI: 0.05–0.58).

Conclusions

These findings suggest that aspirin use is associated with a reduced risk of gastric, esophageal, colorectal, pancreatic, ovarian, endometrial, breast, and prostate cancers, and small intestine neuroendocrine tumors.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4156-5) contains supplementary material, which is available to authorized users.

Meta-analysis of aspirin use and risk of lung cancer shows notable results

Aspirin is a promising agent for chemoprevention of lung cancer. We assessed the association of aspirin use and the development of lung cancer, with a focus on heterogeneity between studies. Databases were searched for relevant studies until September 2014. Studies evaluating the relationship of aspirin use and incidence of lung cancer were considered. Relative risks (RR) were extracted and a pooled estimate was calculated. Heterogeneity was assessed by the I measure, random-effects models, and finite-mixture models. Sources of heterogeneity were investigated using a meta-regression. A decreased risk of lung cancer was found including 20 studies [RR=0.87, 95% confidence interval (CI): 0.79-0.95] on the basis of a random-effects model. Strong heterogeneity was observed (τ=0.0258, I=74.4%). As a result, two subpopulations of studies were identified on the basis of a mixture model. The first subpopulation (42%) has an average RR of 0.64. The remaining subpopulation (58%) shows an RR of 1.04. Different results were found for case-control (RR=0.74, 95% CI: 0.60-0.90) and cohort studies (RR=0.99, 95% CI: 0.93-1.06) in a stratified analysis. In a subgroup analysis, use of aspirin was associated with a decreased risk of non-small-cell lung cancer in case-control studies (RR=0.74; 95% CI: 0.58-0.94). At first glance, our meta-analysis shows an average protective effect. A second glance indicates that there is strong heterogeneity. This leads to a subpopulation with considerable benefit and another subpopulation with no benefit. For further investigations, it is important to identify populations that benefit from aspirin use.

European Code against Cancer 4th Edition: Medical exposures, including hormone therapy, and cancer

The 4th edition of the European Code against Cancer recommends limiting - or avoiding when possible - the use of hormone replacement therapy (HRT) because of the increased risk of cancer, nevertheless acknowledging that prescription of HRT may be indicated under certain medical conditions. Current evidence shows that HRT, generally prescribed as menopausal hormone therapy, is associated with an increased risk of cancers of the breast, endometrium, and ovary, with the risk pattern depending on factors such as the type of therapy (oestrogen-only or combined oestrogen-progestogen), duration of treatment, and initiation according to the time of menopause. Carcinogenicity has also been established for anti-neoplastic agents used in cancer therapy, immunosuppressants, oestrogen-progestogen contraceptives, and tamoxifen. Medical use of ionising radiation, an established carcinogen, can provide major health benefits; however, prudent practices need to be in place, with procedures and techniques providing the needed diagnostic information or therapeutic gain with the lowest possible radiation exposure. For pharmaceutical drugs and medical radiation exposure with convincing evidence on their carcinogenicity, health benefits have to be balanced against the risks; potential increases in long-term cancer risk should be considered in the context of the often substantial and immediate health benefits from diagnosis and/or treatment. Thus, apart from HRT, no general recommendations on reducing cancer risk were given for carcinogenic drugs and medical radiation in the 4th edition of European Code against Cancer. It is crucial that the application of these measures relies on medical expertise and thorough benefit-risk evaluation. This also pertains to cancer-preventive drugs, and self-medication with aspirin or other potential chemopreventive drugs is strongly discouraged because of the possibility of serious, potentially lethal, adverse events.

Modulation by aspirin and naproxen of nucleotide alterations and tumors in the lung of mice exposed to environmental cigarette smoke since birth

Chemoprevention provides an important strategy for cancer control in passive smokers. Due to the crucial role played by smoke-related chronic inflammation in lung carcinogenesis, of special interest are extensively used pharmacological agents, such as nonsteroidal anti-inflammatory drugs (NSAIDs). We evaluated the ability of aspirin and naproxen, inhibitors of both cyclooxygenase-1 and cyclooxygenase -2, to modulate environmental cigarette smoke (ECS)-induced lung carcinogenesis in A/J mice of both genders. Based on a subchronic toxicity study in 180 postweaning mice, we used 1600 mg/kg diet aspirin and 320 mg/kg diet naproxen. In the tumor chemoprevention study, using 320 mice, exposure to ECS started soon after birth and administration of NSAIDs started after weaning. At 10 weeks of life, the NSAIDs did not affect the presence of occult blood in feces. As assessed in a subset of 40 mice, bulky DNA adducts and 8-hydroxy-2'-deoxyguanosine levels were considerably increased in ECS-exposed mice and, irrespective of gender, both NSAIDs remarkably inhibited these nucleotide alterations. After exposure for 4 months followed by 5 months in filtered air, ECS induced a significant increase in the yield of surface lung tumors, the 43.7% of which were adenomas and the 56.3% were adenocarcinomas. Oct-4 (octamer-binding transcription factor 4), a marker of cell stemness, was detected in some adenocarcinoma cells. The NAIDs attenuated the yield of lung tumors, but prevention of ECS-induced lung adenomas was statistically significant only in female mice treated with aspirin, which supports a role for estrogens in ECS-related lung carcinogenesis and highlights the antiestrogenic properties of NSAIDs.

Reducing Cardiovascular and Cancer Risk: How to Address Global Primary Prevention in Clinical Practice

Emerging evidence suggesting the possibility that interventions able to prevent cardiovascular disease (CVD) may also be effective in the prevention of cancer have recently stimulated great interest in the medical community. In particular, data from both experimental and observational studies have demonstrated that aspirin may play a role in preventing different types of cancer. Although the use of aspirin in the secondary prevention of CVD is well established, aspirin in primary prevention is not systematically recommended because the absolute cardiovascular event reduction is similar to the absolute excess in major bleedings. By adding to its cardiovascular prevention benefits, the potential beneficial effect of aspirin in reducing the incidence of mortality and cancer could tip the balance between risks and benefits of aspirin therapy in primary prevention in favor of the latter and broaden the indication for treatment with aspirin in populations at average risk. Prospective and randomized studies are currently investigating the effect of aspirin in prevention of both cancer and CVD; however, clinical efforts at the individual level to promote the use of aspirin in global (or total) primary prevention already could be made on the basis of a balanced evaluation of the benefit/risk ratio.

Aspirin use and lung cancer risk: a possible relationship? Evidence from an updated meta-analysis

Background and Purpose

Growing evidence has emerged and controversial results reported on possible relationship between aspirin use and lung cancer risk. We, therefore, conducted this updated and comprehensive meta-analysis to evaluate this issue, with focus on dose-risk and duration-risk relationships.

Methods

We searched electronic databases including PUBMED, EMBASE and Cochrane library to identify eligible studies. Relative risk (RR) and its 95% confidence interval (CI) were used for cohort studies, while odds ratio (OR) were employed for case-control studies. The random effects and fixed effects models were used for analyses.

Results

18 studies were identified including 19835 lung cancer cases, which were eligible for inclusion in the present meta-analysis. Pooled data from case-control studies showed a significant inverse association between regular aspirin use and lung cancer risk. But for cohort studies, insignificant association was detected with little evidence of heterogeneity (RR: 1.05, 95%CI: 0.95 – 1.16; I²: 10.3%, p value: 0.351). In case-control studies, standard aspirin use (>325mg) was related to lower lung cancer incidence, compared with low-dose aspirin use (75–100mg). A similar trend was observed in cohort studies. Besides, when analysis was restricted to long time regular aspirin use (>5 years), insignificant results were reported in both cohort and case-control studies. Finally, regular aspirin use might result in higher reduction of non-small cell lung cancer incidence among men.

Conclusions

Our findings do not support the protective effect of regular aspirin use on lung cancer risk. Long time aspirin use, sex, dose and type of lung cancer might alter the effect of aspirin use on lung cancer risk. More well-designed studies are needed to further clarify these associations.

Chemopreventive effects of aspirin at a glance

Experimental, epidemiological, and clinical data from the last two decades have each supported the hypothesis that aspirin possesses anticancer properties, and that its use may also reduce the lifetime probability of developing or dying from a number of cancers. Aspirin's ability to act on multiple key metabolic and signaling pathways via inhibition of the cyclooxygenase (COX) enzyme, as well as through COX-independent mechanisms, makes it particularly relevant in the fight against cancer. A growing body of evidence indicates that aspirin may not only reduce cancer risk, but also prevent metastasis and angiogenesis while slowing the rate of mutation-inducing DNA damage. These emerging benefits of aspirin are offset to some extent by the known risks of treatment, such as cardiovascular events and gastrointestinal bleeding. However, it has been shown that pre-treatment risk assessment of individual patients and the use of proton pump inhibitors or Helicobacter pylori eradication therapy concomitantly with aspirin treatment can reduce these potential risks. Thus, the significant benefits of aspirin treatment, coupled with recent data concerning its risks, may prove to tip the balance in favor of aspirin use in cancer prevention.

Can Aspirin and Cancer Prevention be Ageless Companions?

Over the past few decades, the rate of cancer diagnosis has increased worldwide due to the increase in population and average life expectancy, and also, due to the advances in diagnostic medical technology that facilitate early cancer detection and recognition. Nonetheless, the treatment options have not been developed proportional to this increase, with a huge number of patients frequently being diagnosed with different types of fatal cancer. This has prompted different health organizations to search for novel strategies to prevent cancer, or even halt its progression. Having failed to provide optimum vascular protection benefits, especially with the introduction of relatively superior antiplatelets, such as adenosine diphosphate (ADP) receptor inhibitors; clopidogrel and ticagrelor, regular aspirin use was proposed to reduce the risk of common cancers like colorectal cancer, gastric cancer, breast cancer, lung cancer, prostate cancer and haematological malignancies, as suggested by epidemiological studies. However, it is difficult to draw any firm conclusions on such weak data, as this could raise false hopes among patients and physicians and could potentially mislead scientific research. Clearly, current evidence highlights a gap in medical research and emphasizes the need to carry out interventional studies in high risk for cancer patients using specific aspirin doses in order to validate the data. This should also shed some light on the risk-benefit profile in view of the potential for bleeding complications, especially with the higher doses.

Non-steroidal anti-inflammatory drugs and cancer risk in women: results from the Women's Health Initiative

The use of non-steroidal anti-inflammatory drugs (NSAIDs) has been associated with reduced risks of cancers at several sites in some studies; however, we recently reported no association between their use and total cancer risk in women in a prospective study. Here we examine the association between NSAIDs and total and site-specific cancer incidence in the large, prospective Women's Health Initiative (WHI). Women (129,013) were recruited to participate in the WHI at 40 US clinical centers from 1993 to 1998 and followed prospectively. After 9.7 years of follow-up, 12,998 incident, first primary, invasive cancers were diagnosed. NSAID use was systematically collected at study visits. We used Cox proportional hazards regression models to estimate multivariable-adjusted hazard ratios (HR) and 95% confidence intervals (CI) for associations between NSAIDs use and total and site-specific cancer risk. Relative to non-use, consistent use (i.e., use at baseline and year 3 of follow-up) of any NSAID was not associated with total cancer risk (HR 1.00, 95% CI: 0.94-1.06). Results for individual NSAIDs were similar to the aggregate measure. In site-specific analyses, NSAIDs were associated with reduced risks of colorectal cancer, ovarian cancer, and melanoma. Our study confirms a chemopreventive benefit for colorectal cancer in women and gives preliminary evidence for a reduction of the risk of some rarer cancers. NSAIDs' benefit on cancer risk was therefore limited to specific sites and not evident when total cancer risk was examined. This information may be of importance when NSAIDs are considered as chemopreventive agents.

Gene of the month: Interleukin 6 (IL-6)

The Interleukin 6 (IL-6) gene encodes the classic proinflammatory cytokine IL-6. It is also known as interferon-β2 (IFN-β2), B cell stimulatory factor-2 and hybridoma/plasmacytoma growth factor. IL-6 is a multifunctional cytokine with a central role in many physiological inflammatory and immunological processes. Due to its major role in initiation as well as resolving inflammation, deregulation of IL-6 is a mainstay of chronic inflammatory and autoimmune diseases. Additionally, IL-6 has been shown to be implicated in pathogenesis of many human malignancies. Thus, a better understanding of IL-6 and its role in various pathological conditions could enable the development of strategies to use it as a therapeutic target. This short review focuses on the structure, regulation and biological activities of IL-6. In addition we discuss the role of IL-6 in diseases with inflammatory background and cancer and also the therapeutic applications of anti-IL-6 agents.

Lung cancer chemoprevention: current status and future prospects

Lung cancer is the leading cause of cancer death worldwide, making it an attractive disease for chemoprevention. Although avoidance of tobacco use and smoking cessation will have the greatest impact on lung cancer development, chemoprevention could prove to be very effective, particularly in former smokers. Chemoprevention is the use of agents to reverse or inhibit carcinogenesis and has been successfully applied to other common malignancies. Despite prior studies in lung cancer chemoprevention failing to identify effective agents, we now have the ability to identify high-risk populations, and our understanding of lung tumour and premalignant biology continues to advance. There are distinct histological lesions that can be reproducibly graded as precursors of non-small-cell lung cancer and similar precursor lesions exist for adenocarcinoma. These premalignant lesions are being targeted by chemopreventive agents in current trials and will continue to be studied in the future. In addition, biomarkers that predict risk and response to targeted agents are being investigated and validated. In this Review, we discuss the principles of chemoprevention, data from preclinical models, completed clinical trials and observational studies, and describe new treatments for novel targeted pathways and future chemopreventive efforts.

Cruciferous vegetables intake and the risk of colorectal cancer: a meta-analysis of observational studies

BACKGROUND

Epidemiological studies have reported inconsistent associations between cruciferous vegetable (CV) intake and colorectal cancer (CRC) risk. To our knowledge, a comprehensive and quantitative assessment of the association between CV intake and CRC has not been reported.

METHODS

Relevant articles were identified by searching MEDLINE. We pooled the relative risks (RR) from individual studies using a random-effect model and carried out heterogeneity and publication bias analyses.

RESULTS

Twenty-four case-control and 11 prospective studies were included in our analysis. When all studies were pooled, we yielded a significantly inverse association between CV (RR: 0.82; 95% confidence interval 0.75-0.90) intake and CRC risk. Specific analysis for cabbage and broccoli yielded similar result. When separately analyzed, case-control studies of CV intake yield similar results, and the results from the prospective studies showed borderline statistical significance. Moreover, significant inverse associations were also observed in colon cancer and its distal subsite both among prospective and case-control studies.

CONCLUSIONS

Findings from this meta-analysis provide evidence that high intake of CV was inversely associated with the risk of CRC and colon cancer in humans. Further analysis on other specific CV, food preparation methods, stratified results by anatomic cancer site, and subsite of colon cancer should be extended in future study.

Inhibition of the IL-6 signaling pathway: a strategy to combat chronic inflammatory diseases and cancer

Interleukin (IL)-6 is a pro-inflammatory cytokine that produces multifunctional effects. Deregulated IL-6 production and signaling are associated with chronic inflammatory diseases, auto-immunity and cancer. On this basis, inhibition of IL-6 production, its receptors or the signaling pathways are strategies currently being widely pursued to develop novel therapies for a wide range of diseases. This survey aims to provide an updated account of why IL-6 inhibitors are shaping up to become an important class of drugs potentially useful in the treatment of ailments and in particular in inflammation and cancer. In addition we discuss the role of different agents in modulating IL-6 and also recent clinical studies targeting IL-6 in inflammation-mediated diseases and cancer.

Non-steroidal anti-inflammatory drugs and small cell lung cancer risk in the VITAL study

Few studies have examined the association between non-steroidal anti-inflammatory drug (NSAID) use and risk of small cell lung cancer (SCLC); among them, findings are mixed. Recently, we found that use of NSAIDs was differentially associated with lung cancer risk by histology. Here, we examine, more comprehensively, the association between individual NSAIDs and SCLC risk. 75,546 residents of western Washington State, ages 50-76, completed a baseline questionnaire in 2000-2002 and reported on their use of individual NSAIDs over the past 10 years. NSAID use was categorized as non-users, low (<4 days/week or <4 years), and high (≥4 days/week and ≥4 years). 111 SCLC were identified through linkage to a population-based cancer registry. Multivariable-adjusted Cox proportional hazards models including strong adjustment for smoking were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). Compared to non-use, high use of regular-strength aspirin was associated with an elevated risk of SCLC (HR 1.78, 95% CI: 1.05-3.02; P-trend=0.03). Findings for low-dose aspirin were elevated but did not reach statistical significance. Use of non-aspirin NSAIDs was not associated with SCLC risk. Our findings provide further indication of heterogeneity in the association between aspirin and lung cancer morphologies. Large, prospective studies with comprehensive assessments of NSAID use and smoking history and data on both men and women, are needed in order to better understand the association between use of aspirin and SCLC.

Aspirin and cancer risk: a quantitative review to 2011

BACKGROUND

Aspirin has been associated to a reduced risk of colorectal and possibly of a few other common cancers.

METHODS

To provide an up-to-date quantification of this association, we conducted a meta-analysis of all observational studies on aspirin and 12 selected cancer sites published up to September 2011.

RESULTS

Regular aspirin is associated with a statistically significant reduced risk of colorectal cancer [summary relative risk (RR) from random effects models = 0.73, 95% confidence interval (CI) 0.67-0.79], and of other digestive tract cancers (RR = 0.61, 95% CI = 0.50-0.76, for squamous cell esophageal cancer; RR = 0.64, 95% CI = 0.52-0.78, for esophageal and gastric cardia adenocarcinoma; and RR = 0.67, 95% CI = 0.54-0.83, for gastric cancer), with somewhat stronger reductions in risk in case-control than in cohort studies. Modest inverse associations were also observed for breast (RR = 0.90, 95% CI = 0.85-0.95) and prostate cancer (RR = 0.90, 95% CI = 0.85-0.96), while lung cancer was significantly reduced in case-control studies (0.73, 95% CI = 0.55-0.98) but not in cohort ones (RR = 0.98, 95% CI = 0.92-1.05). No meaningful overall associations were observed for cancers of the pancreas, endometrium, ovary, bladder, and kidney.

CONCLUSIONS

Observational studies indicate a beneficial role of aspirin on colorectal and other digestive tract cancers; modest risk reductions were also observed for breast and prostate cancer. Results are, however, heterogeneous across studies and dose-risk and duration-risk relationships are still unclear.

The role of aspirin in cancer prevention

Clinical guidelines for prophylactic aspirin use currently only consider the cardiovascular benefits of aspirin, weighed against the potential harm from aspirin-induced bleeding. Daily aspirin use has been convincingly shown to reduce the risk of colorectal cancer and recurrence of adenomatous polyps, but in average-risk populations, these benefits alone do not outweigh harms from aspirin-induced bleeding. Recently published secondary analyses of cardiovascular trials provide the first randomized evidence that daily aspirin use may also reduce the incidence of all cancers combined, even at low doses (75-100 mg daily). This Review considers the general mechanism of action that defines aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) as a class, the specific advantages of aspirin over other NSAIDs for prophylactic use, the current evidence concerning the main health outcomes affected by aspirin use, and the hypothesis that inhibition of platelet activation may mediate both the cardioprotective and cancer-preventive effects of low-dose aspirin. It also considers how even a 10% reduction in overall cancer incidence beginning during the first 10 years of treatment could tip the balance of benefits and risks favourably in average-risk populations.