Aspirin in the chemoprevention of colorectal neoplasia: an overview

Targeting cyclooxygenase-2 for chemoprevention of inflammation-associated intestinal carcinogenesis: An update

Mounting evidence from preclinical and clinical studies suggests that persistent inflammation functions as a driving force in the journey to cancer. Cyclooxygenase-2 (COX-2) is a key enzyme involved in inflammatory signaling. While being transiently upregulated upon inflammatory stimuli, COX-2 has been found to be consistently overexpressed in human colorectal cancer and several other malignancies. The association between chronic inflammation and cancer has been revisited: cancer can arise when inflammation fails to resolve. Besides its proinflammatory functions, COX-2 also catalyzes the production of pro-resolving as well as anti-inflammatory metabolites from polyunsaturated fatty acids. This may account for the side effects caused by long term use of some COX-2 inhibitory drugs during the cancer chemopreventive trials. This review summarizes the latest findings highlighting the dual functions of COX-2 in the context of its implications in the development, maintenance, and progression of cancer.

Effectiveness of long-term low-dose aspirin in the prevention of gastric cancer after Helicobacter pylori eradication: study design and rationale of Ardabil gastric cancer randomized placebo-controlled prevention trial (AGCPT)

BACKGROUND

In addition to Helicobacter pylori (H. pylori) infection eradication, some medications, including aspirin, metformin, and statins, have been suggested to have protective effects against gastric cancer (GC) development in observational studies. We launched the Ardabil gastric cancer randomized placebo-controlled prevention trial (AGCPT) to evaluate the effectiveness of long-term low-dose aspirin use for the prevention of development and mortality of GC after H. pylori eradication.

METHODS/DESIGN

AGCPT is a prospective population-based double-blind, randomized clinical trial. The study sample was targeted at 21,000 participants aged from 35 to 70 years old, both sexes, in Ardabil, a province in northwest Iran with relatively high rates of GC incidence and mortality. All eligible participants were initially tested for H. pylori infection using a H. pylori stool antigen test. Participants with positive tests undergo H. pylori eradication by standard treatment regimens. All participants with a negative test and those with a positive test with a subsequent confirmed H. pylori eradication test were entered into the intervention phase. In the intervention phase, participants were allocated randomly into either the treatment (daily oral consumption of 81 mg enteric-coated aspirin tablets) arm or the control (placebo) arm using permuted balanced blocks. Subjects will be followed for an average period of 10 years to evaluate the incidence and mortality rates of GC.

DISCUSSION

In addition to preventing other diseases like cardiovascular events, aspirin may prevent GC incidence and mortality. AGCPT will investigate the difference between the two study arms in the proportion of the cumulative incidence and mortality rates of GC. The study's results may help policymakers and researchers update the strategies for GC prevention.

TRIAL REGISTRATION

This trial with the registry name of "The effect of Low-dose Aspirin in the Prevention of Gastric Cancer" was registered in the Iranian Registry of Clinical Trials, IRCT.ir, under the identifier IRCT201105082032N3. Registered on April 21, 2017.

Improved Survival With Adjuvant Cyclooxygenase 2 Inhibition in PIK3CA-Activated Stage III Colon Cancer: CALGB/SWOG 80702 (Alliance)

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported. Observational studies have associated aspirin or cyclooxygenase 2 (COX-2) inhibitor usage either before or after colorectal cancer diagnosis with lower risk of recurrence and suggest that PIK3CA mutational status is predictive of better response to COX-2 inhibition. To prospectively test whether adding the COX-2 inhibitor celecoxib to standard adjuvant chemotherapy reduces the risk of recurrence and improves survival, the National Cancer Institute sponsored the CALGB/SWOG 80702 trial (ClinicalTrials.gov identifier: NCT01150045) for patients with stage III resected colon cancer. Although the primary hypothesis for all patients did not show a statistically significant improvement in disease-free survival (DFS) with celecoxib, subgroup analysis by PIK3CA mutational status was a preplanned study. PIK3CA gain-of-function mutations were detected in 259 of 1,197 tumors with available whole-exome sequencing data. When stratified by PIK3CA status, patients with PIK3CA gain-of-function mutations treated with celecoxib exhibited improved DFS (adjusted hazard ratio [HR], 0.56 [95% CI, 0.33 to 0.96]) compared with PIK3CA wildtype patients (adjusted HR, 0.89 [95% CI, 0.70 to 1.14]), although the interaction test was nonsignificant (Pinteraction = .13). Overall survival was similarly improved for patients with PIK3CA gain-of-function mutations (adjusted HR, 0.44 [95% CI, 0.22 to 0.85]) compared with PIK3CA wildtype patients (adjusted HR, 0.94 [95% CI, 0.68 to 1.30]; Pinteraction = .04). Although the test for heterogeneity in DFS did not reach statistical significance, the results suggest potential utility of PIK3CA to consider selective usage of COX-2 inhibitors in addition to standard treatment for stage III colon cancer.

Development of a risk scoring system for predicting advanced colorectal neoplasia within subcentimetric polyps: A population-based study

OBJECTIVE

To determine a risk scoring system for predicting advanced colorectal neoplasia (ACN) within subcentimetric polyps in a large Asian population.

METHODS

A retrospective study was conducted in Hong Kong SAR, China involving participants who underwent colonoscopy between 2008 and 2015. A random sample of 20 072 subjects were included as the derivation cohort to assess ACN-associated independent factors using logistic regression modeling. Another 8603 subjects formed a validation cohort. A risk scoring system was developed and its performance was assessed using the area under the receiver operating characteristic curve (AUROC).

RESULTS

The risk scores were assigned based on the following criteria: (a) patients who were admitted from inpatient colonoscopy (2.2) or not (1); (b) with three or more chronic diseases (hypertension, diabetes mellitus, hyperlipidemia, heart disease, or cancer) (1.7) or not (1); (c) anemia (1.3) or without anemia (1); (d) receiving aspirin (0.5) or not (1); (e) receiving other nonsteroidal anti-inflammatory drugs (0.3) or not (1); (f) male (1.2) or female gender (1); (g) age <55 (1), 55-64 (1.4), 65-69 (2), 70 years or above (2.2). ACN was more common in those with scores of 2.192 or higher, and they were classified as high risk (HR). The prevalence of ACN in the validation cohort was 13.28% and 3.56% in the HR and low-risk groups, respectively. In both the derivation and validation cohorts, AUROC of the risk-scoring model was 0.7138.

CONCLUSION

Physicians are recommended to utilize this validated score for risk-stratification of patients having subcentimetric polyps.

Effect of Low-Dose Aspirin on the Elderly

Aspirin is a recognized and affordable antiplatelet medicine. Low amounts of aspirin have been used to prevent cardiovascular events, and it is still widely used for primary and secondary stroke prevention. The purpose of this review article is to evaluate the effects of using low doses of aspirin among elderly people. Although taking large dosages of aspirin (500 mg daily) reduces the long-term risk of colorectal cancer, its effectiveness for long-term prevention may be limited by adverse effects. Studies have assessed the relationship between aspirin dosage, incidence, and death in patients with colorectal cancer. Research has indicated that those with diabetes mellitus have an increased risk of cardiovascular events. Low amounts of aspirin have been used to prevent cardiovascular events. However, there is uncertainty regarding the potential benefits and risks associated with preventing the development of cardiovascular problems in individuals with diabetes. The use of aspirin lowers the risk of occlusive vascular events but raises the possibility of bleeding. More attention should be paid to reducing inappropriate aspirin usage in light of its prevalence, particularly among older persons, as the substantial continuous usage of this drug increases the chances of bleeding.

Exploring the potential of quercetin/aspirin-loaded chitosan nanoparticles coated with Eudragit L100 in the treatment of induced-colorectal cancer in rats

Growing evidence suggests quercetin and aspirin may have anticancer properties, notably in the case of colorectal cancer. The goal of this study was to create Pluronic F127 and polyethylene glycol4000 solid dispersion-loaded chitosan nanoparticles for colonic quercetin and aspirin delivery. In 1:1 polymeric stoichiometric ratio, solubility and complex formation were verified. Solid dispersion-loaded chitosan nanoparticles with a diameter of 244.45 ± 8.5 nm, a surface charge of 34.1 ± 3.3 mV, and encapsulation effectiveness of 76.3 ± 4.3% were generated under ideal conditions. In some cases, coating with Eudragit L100 resulted in a decrease in zeta potential and an increase in particle size. The coated formulation released the actives in a pH-dependent manner, considering their physicochemical features. Surprisingly, when compared to the actives' suspension and uncoated formulation, the coated formulation had greater anti-inflammatory efficacy, with a substantial reduction of PGE2 and IL-8 production in colonic tissues (16.9 ± 7.9 ng/g tissue and 134.9 ± 10.1 pg/g tissue, respectively). It also reversed most of the dimethyl hydrazine-induced histological alterations in the colon. It also demonstrated a greater reduction in TNF expression in colonic tissues. As a result, Eudragit L100-coated QT/AS-loaded chitosan nanoparticles are suggested to provide a potential platform for colonic delivery of quercetin and aspirin.

Bacteria in cancer initiation, promotion and progression

Cancer cells originate from a series of acquired genetic mutations that can drive their uncontrolled cell proliferation and immune evasion. Environmental factors, including the microorganisms that colonize the human body, can shift the metabolism, growth pattern and function of neoplastic cells and shape the tumour microenvironment. Dysbiosis of the gut microbiome is now recognized as a hallmark of cancer by the scientific community. However, only a few microorganisms have been identified that directly initiate tumorigenesis or skew the immune system to generate a tumour-permissive milieu. Over the past two decades, research on the human microbiome and its functionalities within and across individuals has revealed microbiota-focused strategies for health and disease. Here, we review the evolving understanding of the mechanisms by which the microbiota acts in cancer initiation, promotion and progression. We explore the roles of bacteria in gastrointestinal tract malignancies and cancers of the lung, breast and prostate. Finally, we discuss the promises and limitations of targeting or harnessing bacteria in personalized cancer prevention, diagnostics and treatment.

Anti-Inflammatory and Immune Properties of Polyunsaturated Fatty Acids (PUFAs) and Their Impact on Colorectal Cancer (CRC) Prevention and Treatment

Colorectal cancer (CRC) remains a leading cause of death from cancer worldwide, with increasing incidence in the Western world. Diet has become the focus of research as a significant risk factor for CRC occurrence, and the role of dietary polyunsaturated fatty acids (PUFAs) has become an area of interest given their potential role in modulating inflammation, particularly in the pro-carcinogenic inflammatory environment of the colon. This work reviews the main types of PUFAs, their characteristics, structure, and physiologic role. We then highlight their potential role in preventing CRC, their signaling function vis-à-vis tumorigenic signaling, and their subsequent potential role in modulating response to different treatment modalities. We review pre-clinical and clinical data and discuss their potential use as adjunct therapies to currently existing treatment modalities. Given our understanding of PUFAs' immune and inflammation modulatory effects, we explore the possible combination of PUFAs with immune checkpoint inhibitors and other targeted therapies.

Aspirin and the metabolic hallmark of cancer: novel therapeutic opportunities for colorectal cancer

Aspirin is a well-known nonsteroidal anti-inflammatory drug (NSAID) that has a recognized role in cancer prevention as well as evidence to support its use as an adjuvant for cancer treatment. Importantly there has been an increasing number of studies contributing to the mechanistic understanding of aspirins' anti-tumour effects and these studies continue to inform the potential clinical use of aspirin for both the prevention and treatment of cancer. This review focuses on the emerging role of aspirin as a regulator of metabolic reprogramming, an essential "hallmark of cancer" required to support the increased demand for biosynthetic intermediates needed for sustained proliferation. Cancer cells frequently undergo metabolic rewiring driven by oncogenic pathways such as hypoxia-inducible factor (HIF), wingless-related integration site (Wnt), mammalian target of rapamycin (mTOR), and nuclear factor kappa light chain enhancer of activated B cells (NF-κB), which supports the increased proliferative rate as tumours develop and progress. Reviewed here, cellular metabolic reprogramming has been identified as a key mechanism of action of aspirin and include the regulation of key metabolic drivers, the regulation of enzymes involved in glycolysis and glutaminolysis, and altered nutrient utilisation upon aspirin exposure. Importantly, as aspirin treatment exposes metabolic vulnerabilities in tumour cells, there is an opportunity for the use of aspirin in combination with specific metabolic inhibitors in particular, glutaminase (GLS) inhibitors currently in clinical trials such as telaglenastat (CB-839) and IACS-6274 for the treatment of colorectal and potentially other cancers. The increasing evidence that aspirin impacts metabolism in cancer cells suggests that aspirin could provide a simple, relatively safe, and cost-effective way to target this important hallmark of cancer. Excitingly, this review highlights a potential new role for aspirin in improving the efficacy of a new generation of metabolic inhibitors currently undergoing clinical investigation.

The role of gut microbiota and drug interactions in the development of colorectal cancer

The human gut microbiota is a complex ecosystem regulating the host's environmental interaction. The same functional food or drug may have varying bioavailability and distinct effects on different individuals. Drugs such as antibiotics can alter the intestinal flora, thus affecting health. However, the relationship between intestinal flora and non-antibiotic drugs is bidirectional: it is not only affected by drugs; nevertheless, it can alter the drug structure through enzymes and change the bioavailability, biological activity, or toxicity of drugs to improve their efficacy and safety. This review summarizes the roles and mechanisms of antibiotics, antihypertensive drugs, nonsteroidal anti-inflammatory drugs, lipid-lowering drugs, hypoglycemic drugs, virus-associated therapies, metabolites, and dietary in modulating the colorectal cancer gut microbiota. It provides a reference for future antitumor therapy targeting intestinal microorganisms.

The Effect of Acetylsalicylic Acid, as a Representative Non-Steroidal Anti-Inflammatory Drug, on the Activity of Myeloperoxidase

BACKGROUND

Acetylsalicylic acid (ASA or aspirin) is one of the world's most widely used non-steroidal anti-inflammatory drug (NSAID). Numerous studies have shown that the long-term use of aspirin may contribute to longer survival among patients with various types of cancer, including ovarian cancer.

AIM

The aim of this study was to investigate the effect of ASA on myeloperoxidase (MPO), which is found at an elevated level in women with ovarian cancer, among others.

METHODS

The influence of different concentrations of ASA on the chlorinating and peroxidase activity of MPO was analysed. The relationship between the concentration of ASA and the degree of inhibition of MPO activity was determined based on the results.

CONCLUSIONS

Aspirin has a significant effect on MPO activity. The use of 50 mM ASA resulted in the enzyme activity being inhibited by more than 90%.

Protective Effects of Long-Term Usage of Cyclo-Oxygenase-2 Inhibitors on Colorectal Cancer in Genetically Predisposed Individuals and Their Overall Effect on Prognosis: A Systematic Review

Colorectal cancer (CRC) is a major global health concern, accounting for significant cancer-related morbidity and mortality worldwide. Despite advancements in early detection and treatment modalities, the prevention of CRC remains a critical goal. Cyclo-oxygenase-2 (COX-2) is an inducible enzyme involved in the production of pro-inflammatory prostaglandins, which play a crucial role in various cellular processes, including inflammation, cell proliferation, apoptosis, and angiogenesis. Elevated COX-2 expression has been consistently observed in colorectal tumors, indicating their role in the pathogenesis of cancer. COX-2 inhibitors, such as celecoxib and rofecoxib, have been studied as potentially effective treatment modalities due to their ability to decrease prostaglandin levels, which are generally higher in cancer patients. Aberrant prostaglandin production is linked to the adenoma-carcinoma sequence, during which adenomas turn dysplastic and accumulate enough damage to become malignant. COX-2 inhibitors have also been shown to modulate various signaling pathways involved in CRC development, such as wingless-related integration site/β-catenin (Wnt/β-catenin), mitogen-activated protein kinase (MAPK), and phosphoinositide-3-kinase-protein kinase B/Akt (PI3K/Akt) pathways. This systematic review aimed to evaluate the protective effects of long-term usage of COX-2 inhibitors on CRC in genetically predisposed individuals and their overall effect on the prognosis of the disease. The researchers conducted a systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines and collected data from several databases, including PubMed, PubMed Central, Cochrane Library, and Web of Science. The search strategy combined keywords related to CRC, COX-2 inhibitors, protective effects, and prognosis. They identified 1189 articles and shortlisted 26 full-text articles that met the eligibility criteria. Quality assessment tools, such as the Assessment of Multiple Systematic Review (AMSTAR) for systematic reviews, the Cochrane bias assessment tool for randomized control trials, the scale for the assessment of narrative review articles (SANRA) checklist for narrative reviews, and the Joanna Briggs Institute (JBI) tool for cross-sectional studies and case reports, are used. This review's conclusions will assist in determining the effectiveness of COX-2 inhibitors to prevent CRC. This review may also contribute to developing guidelines for clinicians to manage genetically predisposed individuals with CRC. Furthermore, the results of this review will shed light on the potential of COX-2 inhibitors as a preventive measure against CRC in genetically predisposed individuals.

In Vitro Assessment of the Synergistic Effect of Aspirin and 5-Fluorouracil in Colorectal Adenocarcinoma Cells

Although remarkable progress has been made, colorectal cancer remains a significant global health issue. One of the most challenging aspects of cancer treatment is the resistance of tumor cells to classical chemotherapy. Conventional therapy for colorectal cancer often involves the use of 5-fluorouracil as a chemotherapeutic agent. Aspirin, a drug used primarily to prevent cardiovascular complications, became a focus of attention due to its potential use as an antitumor agent. The purpose of the study was to evaluate the potential synergistic cytotoxic effects of aspirin and 5-fluorouracil on colorectal adenocarcinoma cells. The viability of cells, the impact on the morphology and nuclei of cells, the potential antimigratory effect, and the impact on the expression of the major genes associated with cell apoptosis (Bcl-2, Bax, Bad), as well as caspases 3 and 8, were evaluated. The results indicated that the two compounds exerted a synergistic effect, causing a reduction in cell viability accompanied by changes characteristic of the apoptosis process-the condensation of nuclei and the reorganization of actin filaments in cells, the reduction in the expression of the Bcl-2 gene, and the increase in the expression of Bax and Bad genes, along with caspases 3 and 8. Considering all these findings, it appears that aspirin may be investigated in depth in order to be used in conjunction with 5-fluorouracil to increase antitumor activity.

Combining gamma-tocopherol and aspirin synergistically suppresses colitis-associated colon tumorigenesis and modulates the gut microbiota in mice, and inhibits the growth of human colon cancer cells

Despite being shown to be effective for chemoprevention of colorectal cancer, aspirin has limitations including adverse effects and inability to block colitis-associated colon cancer (CAC). γ-Tocopherol (γT), a vitamin E form, has been reported to mitigate experimental colitis and CAC, prolong the anti-inflammatory activity of aspirin and alleviate aspirin-induced adverse effect. We therefore hypothesize that combining γT and aspirin is better than either compound singly for suppressing CAC. This hypothesis was tested in the murine azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced CAC model and with human HCT116 colon cancer cells. Compared to the control, combining aspirin (250 ppm) and γT (500 ppm) but not either compound alone significantly reduced AOM/DSS-induced tumor area and multiplicity of large-size tumors by 60% and 50%, respectively. Meanwhile, γT mitigated aspirin-promoted inflammation and stomach lesions in mice. Moreover, the combination appeared to cause favorable changes of gut microbiota compared to the control and synergistically suppressed the growth of HCT116 cells. Our study demonstrates that combining aspirin and γT improves anticancer effects and counteracts side effects compared to aspirin and may therefore be a novel combinatory chemopreventive agent against CAC.

An Aspirin a Day: New Pharmacological Developments and Cancer Chemoprevention

Chemoprevention refers to the use of natural or synthetic agents to reverse, suppress, or prevent the progression or recurrence of cancer. A large body of preclinical and clinical data suggest the ability of aspirin to prevent precursor lesions and cancers, but much of the clinical data are inferential and based on descriptive epidemiology, case control, and cohort studies or studies designed to answer other questions (e.g., cardiovascular mortality). Multiple pharmacological, clinical, and epidemiologic studies suggest that aspirin can prevent certain cancers but may also cause other effects depending on the tissue or disease and organ site in question. The best-known biological targets of aspirin are cyclooxygenases, which drive a wide variety of functions, including hemostasis, inflammation, and immune modulation. Newly recognized molecular and cellular interactions suggest additional modifiable functional targets, and the existence of consensus molecular cancer subtypes suggests that aspirin may have differential effects based on tumor heterogeneity. This review focuses on new pharmacological developments and innovations in biopharmacology that clarify the potential role of aspirin in cancer chemoprevention.

Aspirin and Primary Cancer Risk Reduction in Ischemic Cardiac or Cerebrovascular Disease Survivors: A Nationwide Population-Based Propensity-Matched Cohort Study

Ischemic cardiac or cerebrovascular disease (ICCD) survivors represent a subpopulation with a high cancer risk. Antiplatelet medications, such as aspirin, remain a fundamental therapy for the secondary prevention of ischemic attack in these patients. We conducted a population-based cohort study to investigate the association of long-term low-dose aspirin use with the risk of primary cancer in ICCD survivors. Patients aged ≥20 years with newly diagnosed ICCD (n = 98,519) between January 2000 and December 2013 were identified from the Taiwan National Health Insurance Research Database. The aspirin user and nonuser groups (each n = 24,030) were propensity-matched (1:1) for age, sex, comorbidities, prior medications, ICCD diagnosis year, and year of index dates. The incidence rate of primary cancer was significantly lower in the user group (6.49/1000 person-years) than in the nonuser group (14.04/1000 person-years). Multivariate Cox regression analysis indicated that aspirin use was an independent factor associated with a reduced risk of primary cancer (aHR (95% confidence interval) = 0.42 (0.38−0.45)) after adjustment. Kaplan−Meier curve analysis revealed that the cumulative incidence rate of primary cancer was significantly lower (p < 0.0001) in the user group than in the nonuser group over the 14-year follow-up period. Subgroup analyses demonstrated that this anticancer effect increased with duration of treatment and with similar estimates in women and men. In addition, aspirin use was associated with a reduced risk for seven out of the ten most common cancers in Taiwan. These findings suggest the anticancer effect of aspirin in ICCD survivors and provide information for assessing the benefit-to-risk profile of aspirin as an antiplatelet medication in these patients.

Medical Countermeasure Requirements to Meet NASA's Space Radiation Permissible Exposure Limits for a Mars Mission Scenario

The space radiation environment consists of a complex mixture of ionizing particles that pose significant health risks to crew members. NASA currently requires that an astronaut's career Risk of Exposure Induced Death (REID) for cancer mortality should not exceed 3% at the upper 95% confidence level. This career radiation limit is likely to be exceeded for even the shortest round-trip mission scenario to Mars. As such, NASA has begun to pursue more vigorously approaches to directly reduce radiation risks, despite the large uncertainties associated with such projections. A recent study considered cohort studies of aspirin and warfarin as possible medical countermeasures (MCMs) acting to reduce background cancer mortality rates used in astronaut risk projections. It was shown that such MCMs can reduce the REID for specific tissues in restricted time intervals over which the drugs were administered; however, the cumulative effect on total lifetime REID was minimal. As an extension, the present work addresses more general MCM requirements that would be needed to meet current NASA radiation limits for a Mars mission scenario. A sensitivity analysis is performed within the major components of the NASA cancer risk model that would likely be modified by MCM interventions. This includes the background cancer incidence and mortality rates, epidemiologically based hazard rates derived from acute terrestrial exposures, and radiation quality factors used to translate terrestrial exposures to space radiation. Relationships between possible MCMs and each of these components are discussed. Results from this study provide important information regarding MCM requirements needed to meet NASA limits for planned Mars missions. Insight into the types of countermeasures expected to yield greatest reductions in crew risk is also gained.

Modulation of Reactive Oxygen Species Homeostasis as a Pleiotropic Effect of Commonly Used Drugs

Age-associated diseases represent a growing burden for global health systems in our aging society. Consequently, we urgently need innovative strategies to counteract these pathological disturbances. Overwhelming generation of reactive oxygen species (ROS) is associated with age-related damage, leading to cellular dysfunction and, ultimately, diseases. However, low-dose ROS act as crucial signaling molecules and inducers of a vaccination-like response to boost antioxidant defense mechanisms, known as mitohormesis. Consequently, modulation of ROS homeostasis by nutrition, exercise, or pharmacological interventions is critical in aging. Numerous nutrients and approved drugs exhibit pleiotropic effects on ROS homeostasis. In the current review, we provide an overview of drugs affecting ROS generation and ROS detoxification and evaluate the potential of these effects to counteract the development and progression of age-related diseases. In case of inflammation-related dysfunctions, cardiovascular- and neurodegenerative diseases, it might be essential to strengthen antioxidant defense mechanisms in advance by low ROS level rises to boost the individual ROS defense mechanisms. In contrast, induction of overwhelming ROS production might be helpful to fight pathogens and kill cancer cells. While we outline the potential of ROS manipulation to counteract age-related dysfunction and diseases, we also raise the question about the proper intervention time and dosage.

Cellular Carcinogenesis: Role of Polarized Macrophages in Cancer Initiation

Simple Summary

Inflammation is a hallmark of many cancers. Macrophages are key participants in innate immunity and important drivers of inflammation. When chronically polarized beyond normal homeostatic responses to infection, injury, or aging, macrophages can express several pro-carcinogenic phenotypes. In this review, evidence supporting polarized macrophages as endogenous sources of carcinogenesis is discussed. In addition, the depletion or modulation of macrophages by small molecule inhibitors and probiotics are reviewed as emerging strategies in cancer prevention.

Abstract

Inflammation is an essential hallmark of cancer. Macrophages are key innate immune effector cells in chronic inflammation, parainflammation, and inflammaging. Parainflammation is a form of subclinical inflammation associated with a persistent DNA damage response. Inflammaging represents low-grade inflammation due to the dysregulation of innate and adaptive immune responses that occur with aging. Whether induced by infection, injury, or aging, immune dysregulation and chronic macrophage polarization contributes to cancer initiation through the production of proinflammatory chemokines/cytokines and genotoxins and by modulating immune surveillance. This review presents pre-clinical and clinical evidence for polarized macrophages as endogenous cellular carcinogens in the context of chronic inflammation, parainflammation, and inflammaging. Emerging strategies for cancer prevention, including small molecule inhibitors and probiotic approaches, that target macrophage function and phenotype are also discussed.

Aspirin's effect on kinetic parameters of cells contributes to its role in reducing incidence of advanced colorectal adenomas, shown by a multiscale computational study

Aspirin intake has been shown to lead to significant protection against colorectal cancer, for example with an up to twofold reduction in colorectal adenoma incidence rates at higher doses. The mechanisms contributing to protection are not yet fully understood. While aspirin is an anti-inflammatory drug and can thus influence the tumor microenvironment, in vitro and in vivo experiments have recently shown that aspirin can also have a direct effect on cellular kinetics and fitness. It reduces the rate of tumor cell division and increases the rate of cell death. The question arises whether such changes in cellular fitness are sufficient to significantly contribute to the epidemiologically observed protection. To investigate this, we constructed a class of mathematical models of in vivo evolution of advanced adenomas, parameterized it with available estimates, and calculated population level incidence. Fitting the predictions to age incidence data revealed that only a model that included colonic crypt competition can account for the observed age-incidence curve. This model was then used to predict modified incidence patterns if cellular kinetics were altered as a result of aspirin treatment. We found that changes in cellular fitness that were within the experimentally observed ranges could reduce advanced adenoma incidence by a sufficient amount to account for age incidence data in aspirin-treated patient cohorts. While the mechanisms that contribute to the protective effect of aspirin are likely complex and multi-factorial, our study demonstrates that direct aspirin-induced changes of tumor cell fitness can significantly contribute to epidemiologically observed reduced incidence patterns.

TUMOR CELL MALIGNANCY: A COMPLEX TRAIT BUILT THROUGH RECIPROCAL INTERACTIONS BETWEEN TUMORS AND TISSUE-BODY SYSTEM

Since the discovery of oncogenes and tumor suppressor genes in the late past century, cancer research has been overwhelmingly focused on the genetics and biology of tumor cells and hence has addressed mostly cell-autonomous processes with emphasis on traditional driver/passenger genetic models. Nevertheless, over that same period, multiple seminal observations have accumulated highlighting the role of non-cell autonomous effectors in tumor growth and metastasis. However, given that cell autonomous and non-autonomous events are observed together at the time of diagnosis, it is in fact impossible to know whether the malignant transformation is initiated by cell autonomous oncogenic events or by non-cell autonomous conditions generated by alterations of the tissue-body ecosystem. This review aims at addressing this issue by taking the option of defining malignancy as a complex genetic trait incorporating genetically determined reciprocal interactions between tumor cells and tissue-body ecosystem.

Lifestyle predictors for inconsistent participation to fecal based colorectal cancer screening

BACKGROUND

Consistent participation in colorectal cancer (CRC) screening with repeated fecal immunochemical test (FIT) is important for the success of the screening program. We investigated whether lifestyle risk factors for CRC were related to inconsistent participation in up to four rounds of FIT-screening.

METHOD

We included data from 3,051 individuals who participated in up to four FIT-screening rounds and returned a lifestyle questionnaire. Using logistic regression analyses, we estimated associations between smoking habits, body mass index (BMI), physical activity, alcohol consumption, diet and a healthy lifestyle score (from least favorable 0 to most favorable 5), and inconsistent participation (i.e. not participating in all rounds of eligible FIT screening invitations).

RESULTS

Altogether 721 (24%) individuals were categorized as inconsistent participants Current smoking and BMI ≥30 kg/m2 were associated with inconsistent participation; odds ratios (ORs) and 95% confidence intervals (CIs) were 1.54 (1.21-2.95) and 1.54 (1.20-1.97), respectively. A significant trend towards inconsistent participation by a lower healthy lifestyle score was observed (p < 0.05).

CONCLUSIONS

Lifestyle behaviors were associated with inconsistent participation in FIT-screening. Initiatives aimed at increasing participation rates among those with the unhealthiest lifestyle have a potential to improve the efficiency of screening.

Colorectal Cancer Survivors' Receptivity toward Genomic Testing and Targeted Use of Non-Steroidal Anti-Inflammatory Drugs to Prevent Cancer Recurrence

Genomic testing and targeted use of non-steroidal anti-inflammatory drugs (NSAIDs) may mitigate cancer recurrence risks. This study examines colorectal cancer (CRC) survivors' interest and receptivity to these strategies. Patients diagnosed with stage I-III CRC in 2004-2012 were recruited through the New Mexico Cancer Registry to complete a cancer survivorship experiences survey. We assessed interest in genomic testing, daily aspirin (ASA) and NSAID use, and receptivity to future daily ASA/NSAIDs. Descriptive statistics and multivariable logistic regression models estimated factors associated with genomic testing interest. Receptivity to future ASA/NSAIDs use was estimated for non-users of ASA/NSAIDs. Among CRC survivors (n = 273), 83% endorsed interest in genomic testing, 25% were ASA users and 47% ASA/NSAIDs users. In our final model, genomic testing interest was associated with being uncoupled [OR = 4.11; 95% CI = 1.49-11.35], low income [OR = 0.35, 95% CI: 0.14-0.88], smoking history [OR = 0.35, 95% CI: 0.14-0.90], low [OR: 0.33, 95% CI: 0.07-1.43] and moderate [OR: 0.26, 95% CI: 0.11-0.61] health literacy, and personal CRC risk worry [OR: 2.86, 95% CI: 1.63-5.02, p = 0.0002]. In our final model, ASA use was associated with age [OR: 1.05, 95% CI: 1.01-1.10] and cardiovascular disease history [OR: 2.42, 95% CI: 1.23-4.73, p = 0.010]. Among non-users ASA/NSAIDs, 83% reported receptivity to ASA/NSAIDs to reduce cancer risks, and no significant correlates were identified. The majority of survivors' expressed genomic testing interest and endorsed receptivity toward ASA/NSAIDs use for cancer risk management. Further research to optimize ASA/NSAIDs use guided by genomic testing is warranted.

Low-dose aspirin and incidence of lung carcinoma in patients with chronic obstructive pulmonary disease in Hong Kong: A cohort study

BACKGROUND

Evidence suggests that chronic obstructive pulmonary disease (COPD) is associated with a higher risk of lung carcinoma. Using a territory-wide clinical electronic medical records system, we investigated the association between low-dose aspirin use (≤160 mg) among patients with COPD and incidence of lung carcinoma and the corresponding risk of bleeding.

METHODS AND FINDINGS

This is a retrospective cohort study conducted utilizing Clinical Data Analysis Reporting System (CDARS), a territory-wide database developed by the Hong Kong Hospital Authority. Inverse probability of treatment weighting (IPTW) was used to balance baseline covariates between aspirin nonusers (35,049 patients) with new aspirin users (7,679 patients) among all eligible COPD patients from 2005 to 2018 attending any public hospitals. The median age of the cohort was 75.7 years (SD = 11.5), and 80.3% were male. Competing risk regression with Cox proportional hazards model were performed to estimate the subdistribution hazard ratio (SHR) of lung carcinoma with low-dose aspirin and the associated bleeding events. Of all eligible patients, 1,779 (4.2%, 1,526 and 253 among nonusers and users) were diagnosed with lung carcinoma over a median follow-up period of 2.6 years (interquartile range [IQR]: 1.4 to 4.8). Aspirin use was associated with a 25% lower risk of lung carcinoma (SHR = 0.75, 95% confidence interval [CI] 0.65 to 0.87, p = <0.001) and 26% decrease in lung carcinoma-related mortality (SHR = 0.74, 95% CI 0.64 to 0.86, p = <0.001). Subgroup analysis revealed that aspirin was beneficial for patients aged above or below 75 years, but was also beneficial among populations who were male, nondiabetic, and nonhypertensive. Aspirin use was not associated with an increased risk of upper gastrointestinal bleeding (UGIB) (SHR = 1.19, 95% CI 0.94 to 1.53, p = 0.16), but was associated with an increased risk of hemoptysis (SHR = 1.96, 95% CI 1.73 to 2.23, p < 0.001). The main limitations of the study were (i) that one group of patients may be more likely to seek additional medical attention, although this was partially mitigated by the use of propensity score analysis; and (ii) the observational nature of the study renders it unable to establish causality between aspirin use and lung carcinoma incidence.

CONCLUSIONS

In this study, we observed that low-dose aspirin use was associated with a lower risk of lung carcinoma and lung carcinoma-related mortality among COPD patients. While aspirin was not associated with an increased risk of UGIB, the risk of hemoptysis was elevated.

Appraising the contemporary role of aspirin for primary and secondary prevention of atherosclerotic cardiovascular events

INTRODUCTION

Although the role of aspirin for primary prevention of atherosclerotic cardiovascular disease (ASCVD) has been disputed, its use in secondary ASCVD prevention is well established. Recent trials of primary prevention do not suggest a significant net benefit with aspirin, whereas accruing evidence supports adopting aspirin-free strategies in the context of potent P2Y₁₂ inhibition for the secondary prevention of selected patients undergoing percutaneous coronary intervention.

AREAS COVERED

This updated review aims at summarizing and appraising the pharmacological characteristics and the contemporary role of aspirin for the primary and secondary prevention of ASCVD.

EXPERT OPINION

Recent trials and metanalyses in the context of primary prevention highlighted a modest reduction in ischemic events with aspirin use, counterbalanced by a significant increase in bleeding events. However, ongoing studies on cancer prevention could modify the current paradigm of the unfavorable benefit-risk ratio of aspirin in patients with no overt ASCVD. Conversely, aspirin use is crucial for secondary ASCVD prevention, both in chronic and acute coronary syndromes. Nevertheless, after a brief period of dual antiplatelet therapy, patients at high bleeding risk may benefit from discontinuation of aspirin if a P2Y₁₂ inhibitor is used, hence reducing the bleeding risk with no rebound in thrombotic events.

Diet and Genetic Risk Factors of Colorectal Cancer in Palestine: A Case-Control Study

To add evidence to the limited data available on colorectal cancer (CRC) from Palestine, we examine the risk factors associated with CRC using a matched hospital-based case-control study. A structured questionnaire was used to collect data from 105 cases and 105 controls. A multivariable conditional regression model was used to adjust for the association between study factors and CRC risk. In the model, compared with controls, cases from villages were significantly less likely to have CRC (Adjusted Odds Ratio, AOR = 0.194); taking aspirin lowered the likelihood of CRC by 24%; and having a multiple birth sibling by 33%. Also, the likelihood of CRC was lowered significantly by consuming five servings of fruits/vegetables per week or more (5-6 servings: AOR = 0.21, 7-8 servings per week: AOR = 0.04). However, cases had a significantly higher likelihood of CRC if they consumed 2-4 servings of grilled red meat per week (AOR = 4.25); smoked (AOR = 4.38); had a sedentary lifestyle (AOR = 2.53); reported parental consanguinity (AOR = 3.88); or had a family history of cancer (AOR = 6.39). Our results confirmed the association between CRC and red meat intake and smoking, and proved that parental consanguinity and family history of cancer are also risk factors for CRC.

Chemoprevention by aspirin against inflammation-related colorectal cancer in mice

Inflammation is a primary risk factor for cancer. Epidemiological studies previously demonstrated that aspirin decreased the incidence of cancer and specifically reduced the risk of colorectal cancer. However, the number of animal studies that have confirmed the efficacy of aspirin remains limited. Therefore, the purpose of the present study was to investigate the mechanisms by which aspirin prevents colorectal cancer in mice. ICR mice were treated with azoxymethane and the ulcerative colitis inducer, dextran sodium sulfate, to induce colorectal tumors. Aspirin was orally administered three times per week for 12 weeks. Aspirin significantly reduced the number and size of colorectal tumors. Aspirin also significantly decreased tumor necrosis factor alpha and reactive oxygen species (ROS) levels in the plasma. Immunohistochemical analyses and western blots showed that cyclooxygenase 2 (COX2), inducible nitric oxide synthase (iNOS), and the active form of Yes-associated protein 1 (YAP1), and cytosolic high mobility group box 1 (HMGB1) were strongly expressed at colorectal tumor sites and clearly suppressed by aspirin. An indicator of inflammation-related DNA damage, 8-nitroguanine, also accumulated in the colorectal tissues and was suppressed by aspirin. The present results suggest that the ingestion of aspirin suppressed carcinogenesis caused by inflammation through decreases in COX2 and ROS levels, resulting in reductions in DNA damage and oncogenic YAP1.

Medication use and risk of proximal colon cancer: a systematic review of prospective studies with narrative synthesis and meta-analysis

PURPOSE

Evidence of differences in the etiology of, and poorer survival from, proximal colon compared to the distal colorectum, necessitates research into its risk factors. This systematic review summarizes the evidence on medication use and proximal colon cancer risk.

METHODS

MEDLINE and EMBASE were searched for prospective studies investigating nine medication groups, namely non-steroidal anti-inflammatory drugs (NSAIDs), exogenous hormones, i.e., hormone replacement therapy (HRT) or oral contraceptives (OCs), statins, proton pump inhibitors, anti-hypertensives, metformin (an antidiabetic), antidiarrheals or laxatives, and the risk of proximal colon cancer. Narrative synthesis and meta-analyses, using random effects models to estimate risk ratios (RRs) and 95% confidence intervals (CIs), were conducted.

RESULTS

Twenty nine publications investigating NSAIDs (n = 13), exogenous hormones [HRT (n = 9) or OCs (n = 4)] statins (n = 5), anti-hypertensives (n = 1), and metformin (n = 1) were included. Summary RRs reported a protective effect of aspirin use (RR 0.80, 95% CI 0.73-0.89) but no associations between HRT (RR 0.92, 95% CI 0.83-1.02), OC (RR 1.06, 95% CI 0.98-1.14) or statin use (RR 0.94, 95% CI 0.67-1.31), and proximal colon cancer incidence compared to never/non-use. One study on metformin and one on anti-hypertensives reported no association. Sources of between-study heterogeneity included study design, period of exposure ascertainment, exposure source, and exposure comparison, but this exploration was hindered by the small numbers of studies.

CONCLUSION

Despite some studies on NSAID or HRT use, evidence on the impact of a range of medications on proximal colon cancer risk is limited. This highlights the need for more research to inform chemoprevention strategies.

Associations of Aspirin and Non-Aspirin Non-Steroidal Anti-Inflammatory Drugs With Colorectal Cancer Mortality After Diagnosis

BACKGROUND

Aspirin use reduces colorectal cancer (CRC) incidence, but there is limited evidence regarding associations of aspirin and non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs) with CRC-specific survival.

METHODS

This prospective analysis includes women and men from the Cancer Prevention Study-II Nutrition Cohort who were cancer free at baseline (1992 or 1993) and diagnosed with CRC during incidence follow-up through 2015. Detailed information on aspirin and non-aspirin NSAID use was self-reported on questionnaires at baseline, in 1997, and every 2 years thereafter. Pre- and postdiagnosis data were available for 2686 and 1931 participants without distant metastases, respectively, among whom 512 and 251 died from CRC during mortality follow-up through 2016. Secondary analyses examined associations between prediagnosis aspirin use and stage at diagnosis (distant metastatic vs localized or regional). All statistical tests were 2-sided.

RESULTS

Long-term regular use of aspirin (>15 times per month) before diagnosis was associated with lower CRC-specific mortality (multivariable-adjusted hazard ratio [HR] = 0.69, 95% confidence interval [CI] = 0.52 to 0.92). Postdiagnosis regular aspirin use was not statistically significantly associated with risk of CRC-specific mortality overall (HR = 0.82, 95% CI = 0.62 to 1.09), although participants who began regular aspirin use only after their diagnosis were at lower risk than participants who did not use aspirin at both the pre- and postdiagnosis periods (HR = 0.60, 95% CI = 0.36 to 0.98). Long-term aspirin use before diagnosis was also associated with lower odds of diagnosis with distant metastases (multivariable-adjusted odds ratio = 0.73, 95% CI = 0.53 to 0.99).

CONCLUSIONS

Our results suggest that long-term aspirin use before a diagnosis of nonmetastatic colorectal cancer may be associated with lower CRC-specific mortality after diagnosis, consistent with possible inhibition of micrometastases before diagnosis.

Contemporary Clinical Use of Aspirin: Mechanisms of Action, Current Concepts, Unresolved Questions, and Future Perspectives

The ability of aspirin to inhibit platelet aggregation has positioned this agent within the most frequently used drugs worldwide. The aim of this article is to review the contemporary clinical use of aspirin and also to discuss unresolved issues not yet translated into clinical practice. Results from several clinical trials have led to strong guideline recommendations for aspirin use in the acute management and secondary prevention of cardiovascular disease. On the contrary, guidelines regarding aspirin use as primary prevention of cardiovascular disease are almost conservative, supported by recent trials reporting that the bleeding risk outweighs the potential benefits in most patients. In pregnancy, aspirin has proved efficient in preventing preeclampsia and small-for-gestational-age births in women at high risk, and is hence widely recommended in clinical guidelines. Despite the vast amount of clinical data on aspirin, several unresolved questions remain. Randomized trials have reported that aspirin reduces the risk of recurrent venous thromboembolism, but the clinical relevance remains limited, because direct oral anticoagulants are more effective. Laboratory studies suggest that a twice-daily dosing regimen or evening intake may lead to more efficient platelet inhibition, and the potential clinical benefit of such strategies is currently being explored in ongoing clinical trials. Enteric-coated formulations of aspirin are frequently used, but it remains unclear if they are safer and as efficient as plain aspirin. In the future, aspirin use after percutaneous coronary interventions might not be mandatory in patients who also need anticoagulant therapy, as several trials support shorter aspirin duration strategies. On the other hand, new treatment indications for aspirin will likely arise, as there is growing evidence that aspirin may reduce the risk of colorectal cancer and other types of cancer.

Development of PET Radioligands Targeting COX-2 for Colorectal Cancer Staging, a Review of in vitro and Preclinical Imaging Studies

Colorectal cancer (CRC) is the second most common cause of cancer death, making early diagnosis a major public health challenge. The role of inflammation in tumorigenesis has been extensively explored, and among the identified markers of inflammation, cyclooxygenase-2 (COX-2) expression seems to be linked to lesions with a poor prognosis. Until now, COX-2 expression could only be accessed by invasive methods, mainly by biopsy. Imaging techniques such as functional Positron Emission Tomography (PET) could give access to in vivo COX-2 expression. This could make the staging of the disease more accurate and would be of particular interest in the exploration of the first metastatic stages. In this paper, we review recent progress in the development of COX-2 specific PET tracers by comparing the radioligands' characteristics and highlighting the obstacles that remain to be overcome in order to achieve the clinical development of such a radiotracer, and its evaluation in the management of CRC.

Can Cost-effectiveness Analysis Inform Genotype-Guided Aspirin Use for Primary Colorectal Cancer Prevention?

BACKGROUND

Inherited genetic variants can modify the cancer-chemopreventive effect of aspirin. We evaluated the clinical and economic value of genotype-guided aspirin use for colorectal cancer chemoprevention in average-risk individuals.

METHODS

A decision analytical model compared genotype-guided aspirin use versus no genetic testing, no aspirin. The model simulated 100,000 adults ≥50 years of age with average colorectal cancer and cardiovascular disease risk. Low-dose aspirin daily starting at age 50 years was recommended only for those with a genetic test result indicating a greater reduction in colorectal cancer risk with aspirin use. The primary outcomes were quality-adjusted life-years (QALY), costs, and incremental cost-effectiveness ratio (ICER).

RESULTS

The mean cost of using genotype-guided aspirin was $187,109 with 19.922 mean QALYs compared with $186,464 with 19.912 QALYs for no genetic testing, no aspirin. Genotype-guided aspirin yielded an ICER of $66,243 per QALY gained, and was cost-effective in 58% of simulations at the $100,000 willingness-to-pay threshold. Genotype-guided aspirin was associated with 1,461 fewer polyps developed, 510 fewer colorectal cancer cases, and 181 fewer colorectal cancer-related deaths. This strategy prevented 1,078 myocardial infarctions with 1,430 gastrointestinal bleeding events, and 323 intracranial hemorrhage cases compared with no genetic testing, no aspirin.

CONCLUSIONS

Genotype-guided aspirin use for colorectal cancer chemoprevention may offer a cost-effective approach for the future management of average-risk individuals.

IMPACT

A genotype-guided aspirin strategy may prevent colorectal cancer, colorectal cancer-related deaths, and myocardial infarctions, while minimizing bleeding adverse events. This model establishes a framework for genetically-guided aspirin use for targeted chemoprevention of colorectal cancer with application toward commercial testing in this population.

Aspirin inhibits prostaglandins to prevents colon tumor formation via down-regulating Wnt production

According to numerous epidemiological studies, aspirin is a non-steroidal anti-inflammatory drug (NSAID) that reduces the occurrence and mortality of colorectal cancer (CRC). However, the underlying mechanisms are not well identified. In an effort to fill these gaps, we administered aspirin on mice one day before induction in an azoxymethane (AOM)/dextran sulfate sodium (DSS) induced CRC model. In this study, we assessed the effects of aspirin on tumorigenesis and tumor cell proliferation. Multi-layer analyses were carried out to identify changes in cytokines, metabolites, level of gene expressions, and proteins associated with tumorigenesis and aspirin treatment. The results showed that aspirin-treated mice developed fewer colon tumors in response to AOM/DSS, and aspirin can actively block cyclooxygenase (COX) metabolism and reduce levels of pro-inflammatory cytokines. In addition, the transcriptomic and proteomic analyses both indicated that aspirin has an inhibitory effect on the Wnt pathway. The in vitro results further indicated that aspirin inhibits WNT6 production, possibly by suppressing its transcription factor NR4A2, which in turn is regulated by prostaglandin E2, thereby ultimately inhibiting the Wnt pathway. These findings improve our understanding of the mechanisms behind aspirin's chemoprevention effect on CRC.

Effect of Celecoxib vs Placebo Added to Standard Adjuvant Therapy on Disease-Free Survival Among Patients With Stage III Colon Cancer: The CALGB/SWOG 80702 (Alliance) Randomized Clinical Trial

Importance

Aspirin and cyclooxygenase 2 (COX-2) inhibitors have been associated with a reduced risk of colorectal polyps and cancer in observational and randomized studies. The effect of celecoxib, a COX-2 inhibitor, as treatment for nonmetastatic colon cancer is unknown.

Objective

To determine if the addition of celecoxib to adjuvant chemotherapy with fluorouracil, leucovorin, and oxaliplatin (FOLFOX) improves disease-free survival in patients with stage III colon cancer.

Design, Setting, and Participants

Cancer and Leukemia Group B (Alliance)/Southwest Oncology Group 80702 was a 2 × 2 factorial design, phase 3 trial conducted at 654 community and academic centers throughout the United States and Canada. A total of 2526 patients with stage III colon cancer were enrolled between June 2010 and November 2015 and were followed up through August 10, 2020.

Interventions

Patients were randomized to receive adjuvant FOLFOX (every 2 weeks) for 3 vs 6 months with or without 3 years of celecoxib (400 mg orally daily; n = 1263) vs placebo (n = 1261). This report focuses on the results of the celecoxib randomization.

Main Outcomes and Measures

The primary end point was disease-free survival, measured from the time of randomization until documented recurrence or death from any cause. Secondary end points included overall survival, adverse events, and cardiovascular-specific events.

Results

Of the 2526 patients who were randomized (mean [SD] age, 61.0 years [11 years]; 1134 women [44.9%]), 2524 were included in the primary analysis. Adherence with protocol treatment, defined as receiving celecoxib or placebo for more than 2.75 years or continuing treatment until recurrence, death, or unacceptable adverse events, was 70.8% for patients treated with celecoxib and 69.9% for patients treated with placebo. A total of 337 patients randomized to celecoxib and 363 to placebo experienced disease recurrence or died, and with 6 years' median follow-up, the 3-year disease-free survival was 76.3% for celecoxib-treated patients vs 73.4% for placebo-treated patients (hazard ratio [HR] for disease recurrence or death, 0.89; 95% CI, 0.76-1.03; P = .12). The effect of celecoxib treatment on disease-free survival did not vary significantly according to assigned duration of adjuvant chemotherapy (P for interaction = .61). Five-year overall survival was 84.3% for celecoxib vs 81.6% for placebo (HR for death, 0.86; 95% CI, 0.72-1.04; P = .13). Hypertension (any grade) occurred while treated with FOLFOX in 14.6% of patients in the celecoxib group vs 10.9% of patients in the placebo group, and a grade 2 or higher increase in creatinine levels occurred after completion of FOLFOX in 1.7% vs 0.5% of patients, respectively.

Conclusions and Relevance

Among patients with stage III colon cancer, the addition of celecoxib for 3 years, compared with placebo, to standard adjuvant chemotherapy did not significantly improve disease-free survival.

Trial Registration

ClinicalTrials.gov Identifier: NCT01150045.

Aspirin in the Prevention of Colorectal Neoplasia

High-quality evidence indicates that regular use of aspirin is effective in reducing the risk for precancerous colorectal neoplasia and colorectal cancer (CRC). This has led to US and international guidelines recommending aspirin for the primary prevention of CRC in specific populations. In this review, we summarize key questions that require addressing prior to broader adoption of aspirin-based chemoprevention, review recent evidence related to the benefits and harms of aspirin use among specific populations, and offer a rationale for precision prevention approaches. We specifically consider the mechanistic implications of evidence showing differences in aspirin's effects according to age, the potential role of modifiable mechanistic biomarkers for personalizing prevention, and emerging evidence that the gut microbiota may offer novel aspirin-associated preventive targets to reduce high-risk neoplasia.

Updates on the molecular mechanisms of aspirin in the prevention of colorectal cancer: Review

Colorectal cancer is one of the commonest malignancies worldwide. The estimated lifetime risk of the disease is about 5% with an incidence of one million new cases and 600,000 deaths worldwide every year. It is estimated that in 2019, approximately 134,490 new cases of colorectal cancer will be diagnosed with 49,190 mortalities. Though the disease is regarded as a disorder of the more developed world, the occurrence is steadily increasing in many developing countries. Since chronic inflammation is a known aggravating risk factor for colorectal cancer, anti-inflammatory agents such as aspirin have been used to prevent the development of colorectal cancer and related mortality. The potential mechanisms for the effect of aspirin in the prevention of colorectal cancer have been proposed and broadly classified as cyclooxygenase (COX) dependent and COX-independent. Some of the primary effectors of COX-dependent mechanisms in carcinogenesis are likely to be prostaglandins. In contrast to the reversible action of other nonsteroidal anti-inflammatory drugs, aspirin is known to irreversibly inactivate COX enzymes to suppress production of prostaglandins. COX-independent mechanisms of anticancer effects of aspirin include down-regulation of nuclear factor kappa B activity and Akt activation, modulation of Bcl-2 and Bax family proteins, suppression of vascular endothelial growth factor, induction of apoptosis, disruption of DNA repair mechanisms, and induction of spermidine/spermine N¹-acetyltransferase that modulates polyamine catabolism.

Aspirin for prevention of colorectal cancer in the elderly: friend or foe?

Cancer is the leading cause of death among men and women aged 60-79 years. Colorectal cancer is the third most common cancer in males and the second most common in females, with about 0.8 million deaths worldwide per year. Individuals older than 50 years account for 20-50% of colonic adenomas. Several measures have been proposed to decrease colorectal cancer risks, such as an increase in dietary fiber, use of aspirin, and physical activity. Nonsteroidal anti-inflammatory drugs have been proposed as protective agents against the development of colorectal cancer and colorectal adenomas. Aspirin was the first pharmacological agent endorsed by the United States Preventive Services Task Force screening for colorectal cancer chemoprevention. Although studies have shown up to 40% colorectal cancer risk reduction in individuals at average risk, data regarding this benefit are inconsistent. Several recent studies show that prophylactic use of aspirin in elderly subjects may not be beneficial in preventing the occurrence of colorectal cancers. Given the risks associated with aspirin, such as non-fatal and fatal bleeding events, aspirin's role should be redefined, especially in individuals at risk of bleeding. This review provides a discussion of the recent studies on the role of aspirin use in elderly individuals at risk of colorectal cancer.

Acetylsalicylic Acid Exerts Potent Antitumor and Antiangiogenic Effects in Cutaneous and Uveal Melanoma Cell Lines

Introduction

Acetylsalicylic acid (ASA) has been investigated for a potential anticancer role in several cancers, such as colorectal, ovarian, and endometrial cancer. Moreover, ASA has been shown to abrogate various processes that contribute to tumor growth and progression.

Objective

The aim of this study was to evaluate the effects of ASA on cutaneous melanoma (CM) and uveal melanoma (UM).

Methods

Human CM and UM cells were treated with 5 mM ASA and assessed for changes in cellular functions. Antiangiogenic effects of ASA were determined using an ELISA-based assay for 10 proangiogenic cytokines, and then validated by Western blot. Finally, proteomic analysis of ASA-treated cells was performed to elucidate the changes that may be responsible for ASA-mediated effects in melanoma cells.

Results

Treatment with ASA significantly inhibited the proliferation, invasion, and migration capabilities, and caused a significant decrease in angiogenin and PIGF secretion in both CM and UM. Mass spectrometry revealed 179 protein changes associated with ASA in the CM and UM cell lines.

Conclusions

These results suggest that ASA may be effective as an adjuvant therapy in metastatic CM and UM. Future studies are needed to determine the regulating targets that are responsible for the antitumor effects of ASA.

Targeting Lipid Metabolism in Liver Cancer

Cancer cells are highly dependent on different metabolic pathways for sustaining their survival, growth, and proliferation. Lipid metabolism not only provides the energetic needs of the cells but also provides the raw material for cellular growth and the signaling molecules for many oncogenic pathways. Mainly processed in the liver, lipids play an essential role in the physiology of this organ and in the pathological progression of many diseases such as metabolic syndrome and hepatocellular carcinoma (HCC). The progression of HCC is associated with inflammation and complex metabolic reprogramming, and its prognosis remains poor because of the lack of effective therapies despite many years of dedicated research. Defects in hepatic lipid metabolism induce abnormal gene expression and rewire many cellular pathways involved in oncogenesis and metastasis, implying that interfering with lipid metabolism within the tumor and the surrounding microenvironment may be a novel therapeutic approach for treating liver cancer patients. Therefore, this review focuses on the latest advances in drugs targeting lipid metabolism and leading to promising outcomes in preclinical studies and some ongoing clinical trials.

Microbiota and Cancer: The Emerging Beneficial Role of Bifidobacteria in Cancer Immunotherapy

Many intestinal bacteria are believed to be involved in various inflammatory and immune processes that influence tumor etiology because of their metabolic properties and their ability to alter the microbiota homeostasis. Although many functions of the microbiota are still unclear, there is compelling experimental evidence showing that the intestinal microbiota is able to modulate carcinogenesis and the response to anticancer therapies, both in the intestinal tract and other body sites. Among the wide variety of gut-colonizing microorganisms, various species belonging to the Bifidobacterium genus are believed to elicit beneficial effects on human physiology and on the host-immune system. Recent findings, based on preclinical mouse models and on human clinical trials, have demonstrated the impact of gut commensals including bifidobacteria on the efficacy of tumor-targeting immunotherapy. Although the underlying molecular mechanisms remain obscure, bifidobacteria and other microorganisms have become a promising aid to immunotherapeutic procedures that are currently applied to treat cancer. The present review focuses on strategies to recruit the microbiome in order to enhance anticancer responses and develop therapies aimed at fighting the onset and progression of malignancies.

Randomised clinical study: oral aspirin 325 mg daily vs placebo alters gut microbial composition and bacterial taxa associated with colorectal cancer risk

BACKGROUND

Aspirin is associated with decreased risk of colorectal cancer (CRC), potentially by modulating the gut microbiome.

AIMS

To evaluate the effect of aspirin on the gut microbiome in a double-blinded, randomised placebo-controlled pilot trial.

METHODS

Healthy volunteers aged 50-75 received a standard dose of aspirin (325 mg, N = 30) or placebo (N = 20) once daily for 6 weeks and provided stool samples every 3 weeks for 12 weeks. Serial measurements of gut microbial community composition and bacterial abundance were derived from 16S rRNA sequences. Linear discriminant analysis of effect size (LEfSe) was tested for between-arm differences in bacterial abundance. Mixed-effect regression with binomial distribution estimated the effect of aspirin use on changes in the relative abundance of individual bacterial taxa via an interaction term (treatment × time).

RESULTS

Over the study period, there were differences in microbial composition in the aspirin vs placebo arm. After treatment, four taxa were differentially abundant across arms: Prevotella, Veillonella, Clostridium XlVa and Clostridium XVIII clusters. Of pre-specified bacteria associated with CRC (n = 8) or aspirin intake (n = 4) in published studies, interactions were significant for four taxa, suggesting relative increases in Akkermansia, Prevotella and Ruminococcaceae and relative decreases in Parabacteroides, Bacteroides and Dorea in the aspirin vs placebo arm.

CONCLUSION

Compared to placebo, aspirin intake influenced several microbial taxa (Ruminococcaceae, Clostridium XlVa, Parabacteroides and Dorea) in a direction consistent with a priori hypothesis based on their association with CRC. This suggests that aspirin may influence CRC development through an effect on the gut microbiome. The findings need replication in a larger trial.

Terminal ileum intubation is not associated with colonoscopy quality measures

BACKGROUND AND AIM

Intubation of the terminal ileum (TI) demonstrates a complete colonoscopy, but its clinical value during screening exams is unknown. We aimed to determine whether TI intubation during screening colonoscopy is associated with colonoscopy quality measures or identifies subclinical pathology.

METHODS

We performed a retrospective cohort study examining average-risk screening colonoscopies performed at an academic health system between July 2016 and October 2017. Data were extracted from an internal colonoscopy quality registry and the electronic health record. Appropriate statistical tests were used for group comparisons, to correlate TI intubation rate (TIIR) with measures of colonoscopy quality and to examine factors associated with the likelihood of TI intubation.

RESULTS

There were 7799 colonoscopies performed with adequate prep quality by 28 gastroenterologists. Most patients were female (56.4%) with a median age of 58. The median TIIR was 37.0%, with significant variability among physicians (2-93%). The detection rates for all polyps, adenomas, and sessile serrated polyps were 62.1%, 45.5%, and 7.2%, respectively, and none correlated with TIIR. Intubation of the TI was associated with significantly longer withdrawal times. In a random 10% sample of cases with TI intubation, no clinically significant pathology was found.

CONCLUSIONS

There is wide variability in TIIR among endoscopists. Except to provide photodocumentation of exam extent when other images may be difficult to obtain, the lack of correlation between TI intubation and meaningful clinical outcomes together with the associated time costs suggest routine TI intubation during screening colonoscopy may not be warranted.

Aspirin and the chemoprevention of cancers: A mathematical and evolutionary dynamics perspective

Epidemiological data indicate that long-term low dose aspirin administration has a protective effect against the occurrence of colorectal cancer, both in sporadic and in hereditary forms of the disease. The mechanisms underlying this protective effect, however, are incompletely understood. The molecular events that lead to protection have been partly defined, but remain to be fully characterized. So far, however, approaches based on evolutionary dynamics have not been discussed much, but can potentially offer important insights. The aim of this review is to highlight this line of investigation and the results that have been obtained. A core observation in this respect is that aspirin has a direct negative impact on the growth dynamics of the cells, by influencing the kinetics of tumor cell division and death. We discuss the application of mathematical models to experimental data to quantify these parameter changes. We then describe further mathematical models that have been used to explore how these aspirin-mediated changes in kinetic parameters influence the probability of successful colony growth versus extinction, and how they affect the evolution of the tumor during aspirin administration. Finally, we discuss mathematical models that have been used to investigate the selective forces that can lead to the rise of mismatch-repair deficient cells in an inflammatory environment, and how this selection can be potentially altered through aspirin-mediated interventions. This article is categorized under: Models of Systems Properties and Processes > Mechanistic Models Analytical and Computational Methods > Analytical Methods Analytical and Computational Methods > Computational Methods.

Associations of Novel Dietary and Lifestyle Inflammation Scores with Incident, Sporadic Colorectal Adenoma

BACKGROUND

Colorectal carcinogenesis is mechanistically linked to inflammation and is highly associated with diet and lifestyle factors that may affect chronic inflammation. We previously developed dietary (DIS) and lifestyle (LIS) inflammation scores, comprising inflammation biomarker-weighted components, to characterize the collective contributions of 19 food groups and four lifestyle exposures to systemic inflammation. Both scores were more strongly directly associated with circulating inflammation biomarkers in three validation populations, including a subset of the study population described below, than were the previously reported dietary inflammatory index and empirical dietary inflammatory pattern.

METHODS

We calculated the DIS and LIS in three pooled case-control studies of incident, sporadic colorectal adenoma (N = 765 cases and 1,986 controls) with extensive dietary and lifestyle data, and investigated their associations with adenoma using multivariable unconditional logistic regression.

RESULTS

For those in the highest (more proinflammatory) relative to the lowest (more anti-inflammatory) quintiles of the DIS and LIS, the multivariable-adjusted ORs were 1.31 [95% confidence interval (CI), 0.98-1.75; P _trend = 0.09] and 1.98 (95% CI, 1.48-2.66; P _trend < 0.001), respectively. These associations were strongest for adenomas with high-risk characteristics and among men. Those in the highest relative to the lowest joint DIS/LIS quintile had a 2.65-fold higher odds (95% CI, 1.77-3.95) of colorectal adenoma.

CONCLUSIONS

These results support that diets and lifestyles with higher balances of pro- to anti-inflammatory exposures may be associated with higher risk for incident, sporadic colorectal adenoma.

IMPACT

Our findings support further investigation of the DIS and LIS in relation to colorectal neoplasms.

Metabolomics Analysis of Aspirin's Effects in Human Colon Tissue and Associations with Adenoma Risk

Although substantial evidence supports aspirin's efficacy in colorectal cancer chemoprevention, key molecular mechanisms are uncertain. An untargeted metabolomics approach with high-resolution mass spectrometry was used to elucidate metabolic effects of aspirin treatment in human colon tissue. We measured 10,269 metabolic features in normal mucosal biopsies collected at colonoscopy after approximately 3 years of randomized treatment with placebo, 81 or 325 mg/day aspirin from 325 participants in the Aspirin/Folate Polyp Prevention Study. Linear regression was used to identify aspirin-associated metabolic features and network analysis was used to identify pathways and predict metabolite identities. Poisson regression was used to examine metabolic features associations with colorectal adenoma risk. We detected 471 aspirin-associated metabolic features. Aside from the carnitine shuttle, aspirin-associated metabolic pathways were largely distinct for 81 mg aspirin (e.g., pyrimidine metabolism) and 325 mg (e.g., arachidonic acid metabolism). Among aspirin-associated metabolic features, we discovered three that were associated with adenoma risk and could contribute to the chemopreventive effect of aspirin treatment, and which have also previously been associated with colorectal cancer: creatinine, glycerol 3-phosphate, and linoleate. The last two of these are in the glycerophospholipid metabolism pathway, which was associated with 81 mg aspirin treatment and provides precursors for the synthesis of eicosanoids from arachidonic acid upstream of cyclooxygenase inhibition by aspirin. Conversely, carnitine shuttle metabolites were increased with aspirin treatment and associated with increased adenoma risk. Thus, our untargeted metabolomics approach has identified novel metabolites and pathways that may underlie the effects of aspirin during early colorectal carcinogenesis.

Chondroitin Sulphate and Glucosamine Use Depend on Nonsteroidal Anti-inflammatory Drug Use to Modify the Risk for Colorectal Cancer

BACKGROUND

A safe and effective colorectal cancer chemoprevention agent remains to be discovered. There is little evidence regarding the protective effect of chondroitin sulphate and glucosamine on colorectal cancer. We aimed to assess the association between colorectal cancer risk and the use of chondroitin sulphate and glucosamine using a large cohort with dispensed data.

METHODS

We performed a population-based case-control study in Catalonia using primary care reimbursed medication records (SIDIAP database). The study included 25,811 cases with an incident diagnosis of colorectal cancer and 129,117 matched controls between 2010 and 2015.

RESULTS

The prevalence of ever use was 9.0% (n = 13,878) for chondroitin sulphate, 7.3% (n = 11,374) for glucosamine, and 35% for regular use of nonsteroidal anti-inflammatory drugs (NSAID; n = 45,774). A decreased risk of colorectal cancer was observed among chondroitin sulphate use [OR: 0.96; 95% confidence interval (CI), 0.91-1.01], glucosamine use (OR: 0.92; 95% CI, 0.87-0.97), and concurrent use of chondroitin sulphate and glucosamine (OR: 0.83; 95% CI, 0.70-0.98). Especially for glucosamine, there was a dose-response association regarding duration and cumulative dose. The analysis stratified by simultaneous use with other NSAIDs showed that these drugs used without other NSAIDs do not reduce risk (OR: 1.06; 95% CI, 0.74-1.51). However, they may have a synergistic protective effect when used with other NSAIDs (OR: 0.80; 95% CI, 0.72-0.88).

CONCLUSIONS

This study does not provide strong support for an independent protective association of chondroitin sulphate or glucosamine on colorectal cancer risk in our population. However, these drugs may have a synergistic beneficial effect among NSAID users.

IMPACT

Chondroitin sulphate or glucosamine may contribute to the protective effect of NSAID use in colorectal cancer.

Calcium Permeable Channels in Cancer Hallmarks

Cancer, the second cause of death worldwide, is characterized by several common criteria, known as the “cancer hallmarks” such as unrestrained cell proliferation, cell death resistance, angiogenesis, invasion and metastasis. Calcium permeable channels are proteins present in external and internal biological membranes, diffusing Ca²⁺ ions down their electrochemical gradient. Numerous physiological functions are mediated by calcium channels, ranging from intracellular calcium homeostasis to sensory transduction. Consequently, calcium channels play important roles in human physiology and it is not a surprise the increasing number of evidences connecting calcium channels disorders with tumor cells growth, survival and migration. Multiple studies suggest that calcium signals are augmented in various cancer cell types, contributing to cancer hallmarks. This review focuses in the role of calcium permeable channels signaling in cancer with special attention to the mechanisms behind the remodeling of the calcium signals. Transient Receptor Potential (TRP) channels and Store Operated Channels (SOC) are the main extracellular Ca²⁺ source in the plasma membrane of non-excitable cells, while inositol trisphosphate receptors (IP₃R) are the main channels releasing Ca²⁺ from the endoplasmic reticulum (ER). Alterations in the function and/or expression of these calcium channels, as wells as, the calcium buffering by mitochondria affect intracellular calcium homeostasis and signaling, contributing to the transformation of normal cells into their tumor counterparts. Several compounds reported to counteract several cancer hallmarks also modulate the activity and/or the expression of these channels including non-steroidal anti-inflammatory drugs (NSAIDs) like sulindac and aspirin, and inhibitors of polyamine biosynthesis, like difluoromethylornithine (DFMO). The possible role of the calcium permeable channels targeted by these compounds in cancer and their action mechanism will be discussed also in the review.

Aspirin Protects Melanocytes and Keratinocytes against UVB-Induced DNA Damage In Vivo

UVR promotes skin cancer through multiple mechanisms, including induction of inflammation, oxidative stress, and DNA damage such as 8-oxoguanine and cyclobutane pyrimidine dimers. We investigated whether the anti-inflammatory activities of aspirin (acetylsalicylic acid [ASA]) could protect against UVB-induced DNA damage and skin carcinogenesis. ASA reduced UVB-induced 8-oxoguanine and cyclobutane pyrimidine dimers in Melan-A melanocytes and HaCaT keratinocytes. Skin from UVB-irradiated C57BL/6 mice receiving 0.4 mg ASA daily by gavage exhibited less inflammation, fewer sunburn cells, and reduced 8-oxoguanine lesions than skin from irradiated control animals. ASA similarly reduced UVB-induced sunburn cells, 8-oxoguanine, and cyclobutane pyrimidine dimer lesions in skin of melanoma-prone TN^61R mice, and this was associated with decreased prostaglandin E₂ in plasma and skin. These effects of ASA, however, did not delay melanoma onset in TN^61R mice exposed to a single neonatal dose of UVB. In SKH1-E mice prone to squamous cell carcinoma, ASA reduced plasma and skin prostaglandin E₂ levels and indices of UVB-induced DNA damage and delayed squamous cell carcinoma onset induced by chronic UVB. These results indicate that ASA can protect against UVB-induced inflammation in skin and reduce UVB-induced DNA damage in both melanocytes and keratinocytes. These effects translated into greater chemopreventive efficacy for UVB-induced squamous cell carcinoma than melanoma mouse models.

Do Aspirin and Flavonoids Prevent Cancer through a Common Mechanism Involving Hydroxybenzoic Acids?-The Metabolite Hypothesis

Despite decades of research to elucidate the cancer preventive mechanisms of aspirin and flavonoids, a consensus has not been reached on their specific modes of action. This inability to accurately pinpoint the mechanism involved is due to the failure to differentiate the primary targets from its associated downstream responses. This review is written in the context of the recent findings on the potential pathways involved in the prevention of colorectal cancers (CRC) by aspirin and flavonoids. Recent reports have demonstrated that the aspirin metabolites 2,3-dihydroxybenzoic acid (2,3-DHBA), 2,5-dihydroxybenzoic acid (2,5-DHBA) and the flavonoid metabolites 2,4,6-trihydroxybenzoic acid (2,4,6-THBA), 3,4-dihydroxybenzoic acid (3,4-DHBA) and 3,4,5-trihydroxybenzoic acid (3,4,5-THBA) were effective in inhibiting cancer cell growth in vitro. Limited in vivo studies also provide evidence that some of these hydroxybenzoic acids (HBAs) inhibit tumor growth in animal models. This raises the possibility that a common pathway involving HBAs may be responsible for the observed cancer preventive actions of aspirin and flavonoids. Since substantial amounts of aspirin and flavonoids are left unabsorbed in the intestinal lumen upon oral consumption, they may be subjected to degradation by the host and bacterial enzymes, generating simpler phenolic acids contributing to the prevention of CRC. Interestingly, these HBAs are also abundantly present in fruits and vegetables. Therefore, we suggest that the HBAs produced through microbial degradation of aspirin and flavonoids or those consumed through the diet may be common mediators of CRC prevention.