Aspirin and colorectal cancer: the promise of precision chemoprevention

Obesity Suppresses Cell-Competition-Mediated Apical Elimination of RasV12-Transformed Cells from Epithelial Tissues

Recent studies have revealed that newly emerging transformed cells are often eliminated from epithelial tissues via cell competition with the surrounding normal epithelial cells. This cancer preventive phenomenon is termed epithelial defense against cancer (EDAC). However, it remains largely unknown whether and how EDAC is diminished during carcinogenesis. In this study, using a cell competition mouse model, we show that high-fat diet (HFD) feeding substantially attenuates the frequency of apical elimination of RasV12-transformed cells from intestinal and pancreatic epithelia. This process involves both lipid metabolism and chronic inflammation. Furthermore, aspirin treatment significantly facilitates eradication of transformed cells from the epithelial tissues in HFD-fed mice. Thus, our work demonstrates that obesity can profoundly influence competitive interaction between normal and transformed cells, providing insights into cell competition and cancer preventive medicine.

Sasaki et al. demonstrate using a cell competition mouse model that high-fat diet feeding substantially attenuates the frequency of apical elimination of RasV12-transformed cells from intestinal and pancreatic epithelia. These results indicate that obesity can profoundly influence competitive interaction between normal and transformed cells at the initial stage of carcinogenesis.

Effects of Aspirin or Clopidogrel on Colorectal Cancer Chemoprevention in Patients with Type 2 Diabetes Mellitus

Background: The effect of clopidogrel, whose mechanism of action differs from that of aspirin, on CRC risk remains unknown. We investigated the effects of clopidogrel and aspirin, either as monotherapy or combined, on colorectal cancer (CRC) risk in patients with Type 2 diabetes mellitus (T2DM). Methods: We conducted a cohort study using Taiwan National Health Insurance Research Database. Four groups comprising 218,903 patients using aspirin monotherapy, 20,158 patients using clopidogrel monotherapy, 42,779 patients using dual antiplatelet therapy, and 281,840 nonuser matched controls were created using propensity score matching. Cox proportional hazards regression was used to evaluate the CRC risk during follow-up. Results: During the 13-year follow-up period, we found 9431 cases of CRC over 3,409,522 person-years. The overall incidence rates of CRC were 2.04, 3.45, 1.55, and 3.52 per 1000 person-years in the aspirin, clopidogrel, dual antiplatelet, and nonuser cohorts, respectively. The adjusted hazard ratios (aHRs) were 0.59 (95% confidence interval [CI], 0.56–0.61), 0.77 (95% CI, 0.68–0.87), and 0.37 (95% CI, 0.33–0.40) for the aspirin, clopidogrel, and dual antiplatelet cohorts, respectively. Dose- and duration-dependent chemopreventive effects were observed in the three cohorts.

AACR White Paper: Shaping the Future of Cancer Prevention - A Roadmap for Advancing Science and Public Health

The recent pace, extent, and impact of paradigm-changing cancer prevention science has been remarkable. The American Association for Cancer Research (AACR) convened a 3-day summit, aligned with five research priorities: (i) Precancer Atlas (PCA). (ii) Cancer interception. (iii) Obesity-cancer linkage, a global epidemic of chronic low-grade inflammation. (iv) Implementation science. (v) Cancer disparities. Aligned with these priorities, AACR co-led the Lancet Commission to formally endorse and accelerate the NCI Cancer Moonshot program, facilitating new global collaborative efforts in cancer control. The expanding scope of creative impact is perhaps most startling-from NCI-funded built environments to AACR Team Science Awarded studies of Asian cancer genomes informing global primary prevention policies; cell-free epigenetic marks identifying incipient neoplastic site; practice-changing genomic subclasses in myeloproliferative neoplasia (including germline variant tightly linked to JAK2 V617F haplotype); universal germline genetic testing for pancreatic cancer; and repurposing drugs targeting immune- and stem-cell signals (e.g., IL-1β, PD-1, RANK-L) to cancer interception. Microbiota-driven IL-17 can induce stemness and transformation in pancreatic precursors (identifying another repurposing opportunity). Notable progress also includes hosting an obesity special conference (connecting epidemiologic and molecular perspectives to inform cancer research and prevention strategies), co-leading concerted national implementation efforts in HPV vaccination, and charting the future elimination of cancer disparities by integrating new science tools, discoveries and perspectives into community-engaged research, including targeted counter attacks on e-cigarette ad exploitation of children, Hispanics and Blacks. Following this summit, two unprecedented funding initiatives were catalyzed to drive cancer prevention research: the NCI Cancer Moonshot (e.g., PCA and disparities); and the AACR-Stand Up To Cancer bold "Cancer Interception" initiative.

Effects of Colorectal Cancer Risk Factors on the Association Between Aspirin and Colorectal Cancer

BACKGROUND/AIM

We investigated the effect of aspirin on colorectal cancer (CRC) risk among subgroups of women with and without risk factors for CRC.

PATIENTS AND METHODS

Using data from the Women's Health Initiative, we estimated hazard ratios for CRC in association with aspirin use, with stratifications by cardiovascular disease (CVD) risk status, family history of CRC, and history of colorectal polypectomy.

RESULTS

Aspirin was associated with a lower risk of CRC among women with low/normal or high CVD-risk status; no family history of CRC; or a history of colonoscopy with polypectomy. Aspirin was not associated with CRC among women with a family history of CRC or a history of colonoscopy without polypectomy.

CONCLUSION

Aspirin was associated with a lower risk of CRC in women at all levels of CVD-risk, in those with a history of colonoscopy with polypectomy, and in those without a family history of CRC.

The Impending Epidemic of Cardiovascular Diseases in Patients With Cancer in Japan

Onco-cardiology, a new academic field, aims to improve the quality of life and prognosis of cancer patients and survivors with cardiovascular diseases (CVD). With the aging of the population, an epidemic of cancer with CVD is emerging in developed countries. Cancer and CVD share risk factors, pathophysiology, treatments, and preventive and rehabilitative measures. A multidisciplinary team-based approach is needed to support cancer treatment to maximize its effectiveness and minimize its cardiotoxic potential. Basic and clinical onco-cardiology are already being practiced harmoniously. However, systematization in academia and clinical practice and accumulation of evidence have just started. In this review, we present the epidemiology, common risk factors between cancer and CVD, future epidemic of CVD in patients with cancer, and the necessity for an onco-cardiological approach to managing the burden of CVD in cancer patients and survivors.

Use of Phosphodiesterase 5 Inhibitors Is Associated With Lower Risk of Colorectal Cancer in Men With Benign Colorectal Neoplasms

BACKGROUND & AIMS

Phosphodiesterase 5 (PDE5) inhibitors have been proposed to have chemopreventative effects on colorectal cancer (CRC), although data are needed from population-based studies. We performed a nationwide cohort study to investigate the association between the use of PDE5 inhibitors and the risk of CRC in men with benign colorectal neoplasms.

METHODS

We identified men who received a diagnosis of benign colorectal neoplasm from July 2005 through March 2015 who were listed in the Swedish Hospital Discharge Register. We linked data with those from other national Swedish registers to obtain information about the prescription of PDE5 inhibitors and CRC diagnoses. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

A total of 4823 patients were prescribed PDE5 inhibitors during the study period; the incidence rate of CRC was 2.64 per 1000 person-years for men prescribed PDE5 inhibitors compared with 4.46 per 1000 person-years for men without a prescription. We found a significant negative association between PDE5 inhibitor use and risk of CRC (adjusted HR, 0.65; 95% CI, 0.49-0.85); the decreased risk of CRC was associated with an increased cumulative dose of PDE5 inhibitors (P = .003). PDE5 prescription was associated with greater reduction in risk of advanced-stage CRC (adjusted HR, 0.61; 95% CI, 0.37-1.00) than early-stage CRC (adjusted HR, 0.70; 95% CI, 0.50-0.98), but the difference was not significant.

CONCLUSIONS

In a nationwide population-based study of men with a diagnosis of benign colorectal neoplasm in Sweden, we found evidence that use of PDE5 inhibitors is associated with a reduced risk of CRC. Further studies are needed to confirm the observed association.

Effect of low-dose aspirin administration on long-term survival of cirrhotic patients after splenectomy: A retrospective single-center study

BACKGROUND

Cirrhosis is a major risk factor for the development of hepatocellular carcinoma (HCC). Portal vein thrombosis is not uncommon after splenectomy in cirrhotic patients, and many such patients take oral anticoagulants including aspirin. However, the long-term impact of postoperative aspirin on cirrhotic patients after splenectomy remains unknown.

AIM

The main purpose of this study was to investigate the effect of postoperative long-term low-dose aspirin administration on the development of HCC and long-term survival of cirrhotic patients after splenectomy.

METHODS

The clinical data of 264 adult patients with viral hepatitis-related cirrhosis who underwent splenectomy at the First Affiliated Hospital of Xi’an Jiaotong University from January 2000 to December 2014 were analyzed retrospectively. Among these patients, 59 who started taking 100 mg/d aspirin within seven days were enrolled in the aspirin group. The incidence of HCC and overall survival were analyzed.

RESULTS

During follow-up, 41 (15.53%) patients developed HCC and 37 (14.02%) died due to end-stage liver diseases or other serious complications. Postoperative long-term low-dose aspirin therapy reduced the incidence of HCC from 19.02% to 3.40% after splenectomy (log-rank test, P = 0.028). Univariate and multivariate analyses showed that not undertaking postoperative long-term low-dose aspirin therapy [odds ratio (OR) = 6.211, 95% confidence interval (CI): 1.142-27.324, P = 0.016] was the only independent risk factor for the development of HCC. Similarly, patients in the aspirin group survived longer than those in the control group (log-rank test, P = 0.041). Univariate and multivariate analyses showed that the only factor that independently associated with improved overall survival was postoperative long-term low-dose aspirin therapy [OR = 0.218, 95%CI: 0.049-0.960, P = 0.044].

CONCLUSION

In patients with viral hepatitis-related cirrhosis, long-term post-splenectomy administration of low-dose aspirin reduces the incidence of HCC and improves the long-term overall survival.

Are Platelets the Primary Target of Aspirin's Remarkable Anticancer Activity?

Aspirin, when administered at low doses, has emerged as a powerful anticancer drug due to both chemopreventive activity against many forms of cancer and its ability to block metastases when administered postdiagnosis. Platelets, which are often elevated in circulation during the latter stages of cancer, are known to promote epithelial-mesenchymal transition, cancer cell growth, survival in circulation, and angiogenesis at sites of metastases. Low-dose aspirin has been demonstrated to block this procarcinogenic action of platelets. In this article, we present evidence that aspirin's unique ability to irreversibly inhibit platelet cyclooxygenase-1 is a key mechanism by which aspirin exerts anticancer activity.

Platelet count, aspirin use, and characteristics of host inflammatory responses in colorectal cancer

Background

Platelets not only contribute to hemostasis but also to the regulation of inflammatory reactions and cancer pathogenesis. We hypothesized that blood platelet count would be associated with systemic inflammation, the densities of tumor infiltrating immune cells, and survival in colorectal cancer (CRC), and these relationships could be altered by aspirin use.

Methods

We measured blood platelet count in a cohort of 356 CRC patients and analyzed its relationships with tumor and patient characteristics including aspirin use, markers of systemic inflammation (modified Glasgow Prognostic Score, mGPS; serum levels of CRP, albumin, and 13 cytokines), blood hemoglobin levels, five types of tumor infiltrating immune cells (CD3, CD8, FoxP3, Neutrophil elastase, mast cell tryptase), and survival.

Results

Platelet count inversely correlated with blood hemoglobin levels (p < 0.001) and positively correlated with serum levels of CRP and multiple cytokines including IL-1RA, IL-4, IL-6, IL-7, IL-8, IL-12, IFNγ, and PDGF-BB (p < 0.001 for all), while aspirin use was not associated with the levels of systemic inflammatory markers. High platelet count was also associated with high mGPS (p < 0.001) but did not show statistically significant multivariable adjusted associations with the densities of tumor infiltrating immune cells. Higher platelet counts were observed in higher tumor stage (p < 0.001), but platelet count or aspirin use were not associated with patient survival.

Conclusions

High platelet count is associated with systemic inflammation in CRC. This study could not demonstrate statistically significant associations between platelet count, aspirin use, and the densities of tumor infiltrating immune cells.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1950-z) contains supplementary material, which is available to authorized users.

Illuminating the Onco-GPCRome: Novel G protein-coupled receptor-driven oncocrine networks and targets for cancer immunotherapy

G protein-coupled receptors (GPCRs) are the largest gene family of cell membrane-associated molecules mediating signal transmission, and their involvement in key physiological functions is well-established. The ability of GPCRs to regulate a vast array of fundamental biological processes, such as cardiovascular functions, immune responses, hormone and enzyme release from endocrine and exocrine glands, neurotransmission, and sensory perception (e.g. vision, odor, and taste), is largely due to the diversity of these receptors and the layers of their downstream signaling circuits. Dysregulated expression and aberrant functions of GPCRs have been linked to some of the most prevalent human diseases, which renders GPCRs one of the top targets for pharmaceutical drug development. However, the study of the role of GPCRs in tumor biology has only just begun to make headway. Recent studies have shown that GPCRs can contribute to the many facets of tumorigenesis, including proliferation, survival, angiogenesis, invasion, metastasis, therapy resistance, and immune evasion. Indeed, GPCRs are widely dysregulated in cancer and yet are underexploited in oncology. We present here a comprehensive analysis of GPCR gene expression, copy number variation, and mutational signatures in 33 cancer types. We also highlight the emerging role of GPCRs as part of oncocrine networks promoting tumor growth, dissemination, and immune evasion, and we stress the potential benefits of targeting GPCRs and their signaling circuits in the new era of precision medicine and cancer immunotherapies.

Effects of 5-FU and anti-EGFR antibody in combination with ASA on the spherical culture system of HCT116 and HT29 colorectal cancer cell lines

The aim of this study was to examine the effects of 5‑fluorouracil (5‑FU), anti‑epidermal growth factor receptor (EGFR) antibody and aspirin (ASA) on the characteristics of two CRC cell lines, HCT116 and HT29, maintained in a spherical culture system. We observed that the morphology of both the HCT116 and HT29 cell‑derived spheres was significantly impaired and the size of the colonospheres was markedly reduced following treatment with the aforementioned three drugs. In contrast to adherent cultures, the spherical cultures were more resistant to the tested drugs, as was reflected by their capacity to re‑create the colonospheres when sustained in serum‑free medium. Flow cytometric analysis of the drug‑treated HCT116 cell‑derived spheres revealed changes in the fraction of cells expressing markers of cancer stem cells (CSCs), whereas the CSC phenotype of HT29 cell‑derived colonospheres was affected to a lesser extent. All reagents enhanced the percentage of non‑viable cells in the colonospheres despite the diminished fraction of active caspase‑3‑positive cells following treatment of the HT29 cell‑derived spheres with anti‑EGFR antibody. Increased autophagy, assessed by acridine orange staining, was noted following the incubation of the HT29‑colonospheres with ASA and 5‑FU in comparison to the control. Notably, the percentage of cyclooxygenase (COX)‑2‑positive cells was not affected by ASA, although its activity was markedly elevated in the colonospheres incubated with anti‑EGFR antibody. On the whole, the findings of this study indicate that all the tested drugs were involved in different cellular processes, which suggests that they should be considered for the combined therapeutic treatment of CRC, particularly for targeting the population of CSC‑like cells. Thus, cancer cell‑derived spheres may be used as a preferable model for in vitro anticancer drug testing.

Losartan and Vitamin D Inhibit Colonic Tumor Development in a Conditional Apc-Deleted Mouse Model of Sporadic Colon Cancer

Colorectal cancer is a leading cause of cancer deaths. The renin-angiotensin system (RAS) is upregulated in colorectal cancer, and epidemiologic studies suggest RAS inhibitors reduce cancer risk. Because vitamin D (VD) receptor negatively regulates renin, we examined anticancer efficacy of VD and losartan (L), an angiotensin receptor blocker. Control Apc^+/LoxP mice and tumor-forming Apc^+/LoxP Cdx2P-Cre mice were randomized to unsupplemented Western diet (UN), or diets supplemented with VD, L, or VD+L, the latter to assess additive or synergistic effects. At 6 months, mice were killed. Plasma Ca²⁺, 25(OH)D3, 1α, 25(OH)2D3, renin, and angiotensin II (Ang II) were quantified. Colonic transcripts were assessed by qPCR and proteins by immunostaining and blotting. Cancer incidence and tumor burden were significantly lower in Cre+ VD and Cre+ L, but not in the Cre+ VD+L group. In Apc^+/LoxP mice, VD increased plasma 1,25(OH)2D3 and colonic VDR. In Apc^+/LoxP-Cdx2P-Cre mice, plasma renin and Ang II, and colonic tumor AT1, AT2, and Cyp27B1 were increased and VDR downregulated. L increased, whereas VD decreased plasma renin and Ang II in Cre+ mice. VD or L inhibited tumor development, while exerting differential effects on plasma VD metabolites and RAS components. We speculate that AT1 is critical for tumor development, whereas RAS suppression plays a key role in VD chemoprevention. When combined with L, VD no longer increases active VD and colonic VDR in Cre- mice nor suppresses renin and Ang II in Cre+ mice, likely contributing to lack of chemopreventive efficacy of the combination.

Facing the future: challenges and opportunities in adoptive T cell therapy in cancer

INTRODUCTION

In recent years, immunotherapy for the treatment of solid cancer has emerged as a promising therapeutic alternative. Adoptive cell therapy (ACT), especially T cell-based, has been found to cause tumor regression and even cure in a percentage of treated patients. Checkpoint inhibitors further underscore the potential of the T cell compartment in the treatment of cancer. Not all patients respond to these treatments; however, many challenges remain.

AREAS COVERED

This review covers the challenges and progress in tumor antigen target identification and selection, and cell product manufacturing for T cell ACT. Tumor immune escape mechanisms and strategies to overcome those in the context of T cell ACT are also discussed.

EXPERT OPINION

The immunotherapy toolbox is rapidly expanding and improving, and the future promises further breakthroughs in the T cell ACT field. The heterogeneity of the tumor microenvironment and the multiplicity of tumor immune escape mechanisms pose formidable challenges to successful T cell immunotherapy in solid tumors, however. Individualized approaches and strategies combining treatments targeting different immunotherapeutic aspects will be needed in order to expand the applicability and improve the response rates in future.

Identification of potential carcinogenic and chemopreventive effects of prescription drugs: a protocol for a Norwegian registry-based study

INTRODUCTION

Surveillance of unintended effects of pharmaceuticals (pharmacovigilance or drug safety) is crucial, as knowledge of rare or late side effects is limited at the time of the introduction of new medications into the market. Side effects of drugs may involve increased or decreased risk of cancer, but these typically appear after a long induction period. This fact, together with low incidences of many cancer types, limits the usefulness of traditional pharmacovigilance strategies, primarily based on spontaneous reporting of adverse events, to identify associations between drug use and cancer risk. Postmarketing observational pharmacoepidemiological studies are therefore crucial in the evaluation of drug-cancer associations.

METHODS AND ANALYSIS

The main data sources in this project will be the Norwegian Prescription Database and the Cancer Registry of Norway. The underlying statistical model will be based on a multiple nested case-control design including all adult (~200 000) incident cancer cases within the age-range 18-85 years from 2007 through 2015 in Norway as cases. 10 cancer-free population controls will be individually matched to these cases with respect to birth year, sex and index date (date of cancer diagnosis). Drug exposure will be modelled as chronic user/non-user by counting prescriptions, and cumulative use by summarising all dispensions' daily defined doses over time. Conditional logistic regression models adjusted for comorbidity (National Patient Register), socioeconomic parameters (Statistics Norway), concomitant drug use and, for female cancers, reproduction data (Medical Birth Registry), will be applied to identify drug-use-cancer-risk associations.

ETHICS AND DISSEMINATION

The study is approved by the regional ethical committee and the Norwegian data protection authority. Results of the initial screening step and analysis pipeline will be described in a key paper. Subsequent papers will report the evaluation of identified signals in replication studies. Results will be published in peer-reviewed journals, at scientific conferences and through press releases.

Use of Low-Dose Aspirin and Mortality After Prostate Cancer Diagnosis: A Nationwide Cohort Study

BACKGROUND

Recent studies suggest that aspirin use may improve survival in patients with prostate cancer.

OBJECTIVE

To assess the association between postdiagnosis use of low-dose aspirin and prostate cancer mortality.

DESIGN

Nationwide cohort study.

SETTING

Denmark.

PATIENTS

Men with incident prostate adenocarcinoma between 2000 and 2011.

MEASUREMENTS

Nationwide registry data on tumor characteristics, drug use, primary prostate cancer therapy, comorbidity, and socioeconomic parameters. Postdiagnosis use of low-dose aspirin (75 to 150 mg) was defined as 2 or more prescriptions filled within 1 year after prostate cancer diagnosis. Follow-up started 1 year after prostate cancer diagnosis. In secondary analyses, low-dose aspirin use was assessed within exposure periods of 5 or 7.5 years after prostate cancer diagnosis.

RESULTS

Of 29 136 patients (median age, 70 years), 7633 died of prostate cancer and 5575 died of other causes during a median follow-up of 4.9 years (interquartile range, 3.1 to 7.2 years), through 2015. Postdiagnosis low-dose aspirin use was associated with adjusted hazard ratios (HRs) of 0.95 (95% CI, 0.89 to 1.01) for prostate cancer-specific mortality and 1.12 (CI, 1.05 to 1.20) for other-cause mortality. The secondary analyses showed that prostate cancer mortality was slightly reduced with low-dose aspirin use after the 5-year (HR, 0.91 [CI, 0.83 to 1.01]) and 7.5-year (HR, 0.84 [CI, 0.72 to 0.97]) postdiagnosis exposure periods, notably among patients filling prescriptions for a large quantity of low-dose aspirin tablets during the 7.5-year period.

LIMITATIONS

Data on over-the-counter aspirin use were unavailable. Some residual confounding was possible as a result of incomplete data on some prognostic factors.

CONCLUSION

The study did not support an overall effect of postdiagnosis low-dose aspirin use on prostate cancer mortality. However, results for extended exposure periods suggest that low-dose aspirin use might be inversely associated with prostate cancer mortality after 5 years from cancer diagnosis.

PRIMARY FUNDING SOURCE

Danish Cancer Society.

Harnessing the innate immune system and local immunological microenvironment to treat colorectal cancer

Significant progress in the development of new immunotherapies has led to successful clinical trials for malignant melanoma and non-small cell lung cancer; however, for the majority of solid tumours of the gastrointestinal tract, little or no progress has been seen. The efficacy of immunotherapies is limited by the complexities of a diverse set of immune cells, and interactions between the tumour cells and all other cells in the local microenvironment of solid tumours. A large fraction of immune cells present in and around solid tumours derive from the innate arm of the immune system and using these cells against tumours offers an alternative immunotherapeutic option, especially as current strategies largely harness the adaptive arm of the immune system. This option is currently being investigated and attempts at using the innate immune system for gastrointestinal cancers are showing initial results. Several important factors, including cytokines, chemotherapeutics and the microbiome, influence the plasticity and functionality of innate (myeloid) cells in the microenvironment, and this complexity of regulation has limited translation into successful trials so far. In this review, current concepts of the immunobiology of the innate arm in the tumour microenvironment are presented in the context of clinical translation.

Bioactive lipid metabolism in platelet "first responder" and cancer biology

Platelets can serve as "first responders" in cancer and metastasis. This is partly due to bioactive lipid metabolism that drives both platelet and cancer biology. The two primary eicosanoid metabolites that maintain platelet rapid response homeostasis are prostacyclin made by endothelial cells that inhibits platelet function, which is counterbalanced by thromboxane produced by platelets during activation, aggregation, and platelet recruitment. Both of these arachidonic acid metabolites are inherently unstable due to their chemical structure. Tumor cells by contrast predominantly make more chemically stable prostaglandin E₂, which is the primary bioactive lipid associated with inflammation and oncogenesis. Pharmacological, clinical, and epidemiologic studies demonstrate that non-steroidal anti-inflammatory drugs (NSAIDs), which target cyclooxygenases, can help prevent cancer. Much of the molecular and biological impact of these drugs is generally accepted in the field. Cyclooxygenases catalyze the rate-limiting production of substrate used by all synthase molecules, including those that produce prostaglandins along with prostacyclin and thromboxane. Additional eicosanoid metabolites include lipoxygenases, leukotrienes, and resolvins that can also influence platelets, inflammation, and carcinogenesis. Our knowledge base and technology are now progressing toward identifying newer molecular and cellular interactions that are leading to revealing additional targets. This review endeavors to summarize new developments in the field.

Aspirin in people with diabetes: Time to clean up the prescription list?

The effect of aspirin in primary cardiovascular (CV) prevention in people with diabetes is still a matter of debate. Recent results of ASCEND trial suggest that the absolute benefit on CV events is largely counter-balanced by the bleeding risk. However, one crucial question is whether aspirin should be maintained or withdrawn from the prescription list of those who are already under this therapy since a while ago. Indeed, large epidemiological data reported that the aspirin discontinuation was associated to an increased risk of CV events. Moreover, besides the CV outcome, potential positive impact of aspirin on cancer is still under investigation. To conclude, there is no more systematic indication for aspirin in people with diabetes free of CV disease, especially when diabetes and all other CV risk factors are optimally controlled. For those already on aspirin, data are not conclusive enough for a systematic approach and benefit/risk balance must be discussed with patients to take a shared decision.

Does low-dose aspirin use for cardiovascular disease prevention reduce colorectal cancer deaths? A comparison of two cohorts in the Florence district, Italy

Aspirin has been associated with reduced incidence and mortality of colorectal and a few other cancers. The aim of our paper was to study the effect of low-dose aspirin intake on cancer mortality in a population-based cohort study. The study included inhabitants of the Florence district (Italy) at the beginning of 2007. We considered two cohorts: patients who received prescriptions of low-dose aspirin for the whole year and patients who did not have any prescriptions over the same period. We followed the two cohorts until 31 December 2013. By linking with the Tuscany Mortality Registry, we analysed cause-specific mortality. We used a Cox semiparametric model to compare the mortality of the two cohorts. There was an 18% higher probability [hazard ratio (HR)=1.18, 95% confidence interval (CI): 1.12-1.23] for all causes of death among the cohort of aspirin users, almost completely caused by cardiovascular diseases (CVDs) (HR=1.39, 95% CI: 1.29-1.49). Colorectal cancer mortality was reduced by almost 30% (HR=0.71, 95% CI: 0.52-0.97). Death caused by major bleeding was 11% higher (HR=1.11, 95% CI: 0.86-1.44), but not statistically significant. Our results support the hypothesis that the use of low-dose aspirin for CVD prevention reduces colorectal cancer mortality. Given the growing ability to identify subgroups of individuals with an increased risk of developing cancer, further studies are needed to study the effectiveness of different cancer screening strategies tailored to these specific subgroups. Our study suggests the importance of focusing on this issue from the opposite perspective, that is, considering subgroups of individuals at decreased risk, such as the subgroup of individuals who take low-dose aspirin for CVD prevention. Thus, further assessments are needed to possibly identify subgroup-specific screening strategies that would be more effective than those developed for average-risk individuals.

Nitric oxide-donating aspirin (NO-Aspirin) suppresses lung tumorigenesis in vitro and in vivo and these effects are associated with modulation of the EGFR signaling pathway

Although regular aspirin use has been shown to lower the risk of colorectal cancer, its efficacy against lung cancer is weak or inconsistent. Moreover, aspirin use increases the risk of ulcers and stomach bleeding. In this study, we determined the efficacy of nitric oxide-donating aspirin (NO-Aspirin), a safer form of aspirin in which the parent drug is linked to a nitric oxide-releasing moiety through a spacer, to suppress lung tumorigenesis. Under in vitro conditions, NO-Aspirin significantly reduced the proliferation and survival of tumorigenic bronchial cell line (1170) and non-small cell lung cancer (NSCLC) cell lines (A549, H1650, H1975 and HCC827) and colony formation by NSCLC cells at sub- or low micromolar concentrations (≤1 µM for 1170 cells and ≤6 µM for NSCLC cells) in a COX-2 independent manner. These effects were paralleled by suppression of phospho-epidermal growth factor receptor (EGFR), -STAT3, -Akt and -ERK and enhanced caspase 3 and PARP cleavage. Among NSCLC cells, EGFR mutant cells (H1650, H1975 and HCC827) were more sensitive than cells expressing wild-type EGFR (A549) and H1650 cells were the most sensitive. Moreover, NO-Aspirin sensitized H1650 and H1975 cells to the antiproliferative effects of erlotinib, a tyrosine kinase inhibitor. In in vivo studies using 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) + lipopolysaccharide (LPS)-induced model of lung tumorigenesis, NO-Aspirin significantly reduced the number and size of lung tumors, expression of phospho-EGFR and -Akt as well as the pro-inflammatory molecules TNF-α and interferon-gamma. Overall, these results indicate the potential of NO-Aspirin for the chemoprevention of lung cancer in high risk populations.

Cancer prevention and screening: the next step in the era of precision medicine

A primary mode of cancer prevention and early detection in the United States is the widespread practice of screening. Although many strategies for early detection and prevention are available, adverse outcomes, such as overdiagnosis and overtreatment, are prevalent among those utilizing these approaches. Broad use of mammography and prostate cancer screening are key examples illustrating the potential harms stemming from the detection of indolent lesions and the subsequent overtreatment. Furthermore, there are several cancers for which prevention strategies do not currently exist. Clinical and experimental evidence have expanded our understanding of cancer initiation and progression, and have instructed the development of improved, precise modes of cancer prevention and early detection. Recent cancer prevention and early detection innovations have begun moving towards the integration of molecular knowledge and risk stratification profiles to allow for a more accurate representation of at-risk individuals. The future of cancer prevention and early detection efforts should emphasize the incorporation of precision cancer prevention integration where screening and cancer prevention regimens can be matched to one's risk of cancer due to known genomic and environmental factors.

IL-17R deletion predicts high-grade colorectal cancer and poor clinical outcomes

The IL-17 receptor (IL-17R) has a perplexing role in cancer, which may be explained by its yin-yang signaling pathways. Recently, the critical role of IL-17R in maintaining basal levels of A20-a key negative regulator of NF-κB and JNK-c-Jun pathways has been demonstrated in cancer cell lines. Cross-cancer analyses of somatic copy number alterations in IL-17RA, IL-17RC and A20 genes reveal that IL-17RA-deletion is common in colorectal cancer (CRC) patients, representing 24, 26, 37 and 49% of stage I, II, III and IV of patients, respectively, and mutually exclusive with patients displaying microsatellite instability. Importantly, patients with IL-17R-deletion or concurrent deletions of A20 show significantly reduced overall survival. Analysis of multiple published microarray studies confirms that IL-17RA expression is significantly reduced in CRC samples compared to normal counterparts, and its level is closely associated with A20 expression. Analyses of RNAseq data indicate that tumors with IL-17R-deletion express strong molecular markers of tumor invasion, growth and metastasis. Notably, approximately 20 genes responsible for protein synthesis and mitochondrial metabolism are inversely correlated with both IL-17RA and A20. Immunohistochemistry staining in human colorectal tissue arrays further reveals that high-grade tumors have significantly reduced IL-17RA staining compared to low-grade tumors. Thus, collective evidence strongly supports a previously unrecognized CRC-promoting mechanism triggered by IL-17RA-deletion and highlights its utility as a prognostic marker in CRC.

Self-antigen MASH2 combined with the AS15 immunostimulant induces tumor protection in colorectal cancer mouse models

Human achaete scute homolog 2 (HASH2) and its murine ortholog MASH2 are potential targets for colorectal cancer immunotherapy. We assessed immunogenicity and antitumor potential of recombinant MASH2 protein combined with AS15 immunostimulant (recMASH2+AS15) in CB6F1 and Apc^+/Min-FCCC mice. CB6F1 mice received 4 injections of recMASH2+AS15 or AS15 alone before challenge with TC1-MASH2 tumor cells (Tumor Challenge). Apc^+/Min-FCCC mice received 9 injections of recMASH2+AS15 or vehicle (phosphate buffer saline [PBS] or AS15 alone), before (two independent Prophylactic Studies) or after (Immunotherapy) colon adenomas were detectable by colonoscopy. CB6F1 mice immunized with recMASH2+AS15 had a significantly smaller mean tumor size and improved survival rate compared to controls (104 mm² vs. 197 mm² [p = 0.009] and 67% vs. 7% [p = 0.001], respectively). In Prophylactic Study 1, the mean number of colon adenomas was significantly lower in Apc^+/Min-FCCC mice receiving recMASH2+AS15 compared to PBS (1.8 [95% confidence interval 1.0–3.3] vs. 5.2 [3.7–7.4], p = 0.003). Fewer microadenomas were observed in recMASH2+AS15 groups compared to PBS in both Prophylactic Studies (Study 1: mean 0.4 [0.2–1.0] vs. 1.5 [0.9–2.4], p = 0.009; Study 2: 0.4 [0.2–0.6] vs. 1.1 [0.8–1.5], p = 0.001). In the Immunotherapy Study, fewer colon adenomas tended to be observed in recMASH2+AS15-treated mice (4.1 [2.9–6.0]) compared to controls (AS15 4.7 [3.3–6.6]; PBS 4.9 [3.5–6.9]; no significant difference). recMASH2+AS15 induced MASH2-specific antibody and CD4+ responses in both mouse models. recMASH2+AS15 partially protected mice against MASH2-expressing tumors and reduced spontaneous colorectal adenomas in Apc^+/Min-FCCC mice, indicating that MASH2/HASH2 antigens are targets for colorectal cancer immunotherapy.

Insights into Pathogenic Interactions Among Environment, Host, and Tumor at the Crossroads of Molecular Pathology and Epidemiology

Evidence indicates that diet, nutrition, lifestyle, the environment, the microbiome, and other exogenous factors have pathogenic roles and also influence the genome, epigenome, transcriptome, proteome, and metabolome of tumor and nonneoplastic cells, including immune cells. With the need for big-data research, pathology must transform to integrate data science fields, including epidemiology, biostatistics, and bioinformatics. The research framework of molecular pathological epidemiology (MPE) demonstrates the strengths of such an interdisciplinary integration, having been used to study breast, lung, prostate, and colorectal cancers. The MPE research paradigm not only can provide novel insights into interactions among environment, tumor, and host but also opens new research frontiers. New developments-such as computational digital pathology, systems biology, artificial intelligence, and in vivo pathology technologies-will further transform pathology and MPE. Although it is necessary to address the rarity of transdisciplinary education and training programs, MPE provides an exemplary model of integrative scientific approaches and contributes to advancements in precision medicine, therapy, and prevention.

Aspirin Inhibits Natural Killer/T-Cell Lymphoma by Modulation of VEGF Expression and Mitochondrial Function

Extranodal nasal-type natural killer/T-cell lymphoma (NKTCL) is an Epstein-Barr virus (EBV)-associated lymphoma with a strong tendency relapse or be refractory in response to chemotherapy. Development of a new strategy for NKTCL treatment is still quite necessary. In this study, we found that aspirin treatment suppresses VEGF expression in NKTCL SNK-6 cells. Further investigation showed that aspirin treatment increases histone methylation in the range of −100~0 that is proximal to the transcription start site on the VEGF promoter, subsequently decreasing the binding ability of Sp1 to the VEGF promoter with VEGF suppression. Furthermore, aspirin treatment modulates mitochondrial function with increased ROS formation and apoptosis in NKTCL cells. Aspirin treatment alone slightly inhibits NKTCL SNK-6 tumor growth and EBV replication; while in the presence of histone deacetylase inhibitor (HDACi) chidamide (CDM), aspirin significantly suppresses the VEGF signaling pathway with increased ROS overgeneration and EBV inhibition. We also showed that with the addition of chidamide, aspirin significantly suppresses NKTCL tumor growth in both in vitro cell culture and in vivo mouse model with prolonged mouse survival. This is the first time that the potential mechanism for aspirin-mediated VEGF suppression and anti-tumor effect has been discovered, and this study provides a new strategy for anti-tumor drug development for NKTCL treatment based on aspirin-mediated targeting of the VEGF signaling pathway and ROS formation.

Aspirin inhibits the proliferation of hepatoma cells through controlling GLUT1-mediated glucose metabolism

Aspirin can efficiently inhibit liver cancer growth, but the mechanism is poorly understood. In this study, we report that aspirin modulates glucose uptake through downregulating glucose transporter 1 (GLUT1), leading to the inhibition of hepatoma cell proliferation. Our data showed that aspirin significantly decreased the levels of reactive oxygen species (ROS) and glucose consumption in hepatoma cells. Interestingly, we identified that GLUT1 and HIF1α could be decreased by aspirin. Mechanically, we demonstrated that the -1008/-780 region was the regulatory element of transcriptional factor NF-κB in GLUT1 promoter by luciferase report gene assays. PDTC, an inhibitor of NF-κB, could suppress the expression of GLUT1 in HepG2 and H7402 cells, followed by affecting the levels of ROS and glucose consumption. CoCl₂-activated HIF1α expression could slightly rescue the GLUT1 expression inhibited by aspirin or PDTC, suggesting that aspirin depressed GLUT1 through targeting NF-κB or NF-κB/HIF1α signaling. Moreover, we found that GLUT1 was highly expressed in clinical HCC tissues relating to their paired adjacent normal tissues. Importantly, we observed that high level of GLUT1 was significantly correlated with the poor relapse-free survival of HCC patients by analysis of public data. Functionally, overexpression of GLUT1 blocked the PDTC-induced or aspirin-induced inhibition of glucose metabolism in HepG2 cells. Conversely, aspirin failed to work when GLUT1 was stably knocked down in the cells. Administration of aspirin could depress the growth of hepatoma cells through controlling GLUT1 in vitro and in vivo. Thus, our finding provides new insights into the mechanism by which aspirin depresses liver cancer.

Obesity-Linked Cancers: Current Knowledge, Challenges and Limitations in Mechanistic Studies and Rodent Models

The worldwide prevalence of obesity has doubled during the last 50 years, and according to the World Obesity Federation, one third of the people on Earth will be obese by the year 2025. Obesity is described as a chronic, relapsing and multifactorial disease that causes metabolic, biomechanical, and psychosocial health consequences. Growing evidence suggests that obesity is a risk factor for multiple cancer types and rivals smoking as the leading preventable cause for cancer incidence and mortality. The epidemic of obesity will likely generate a new wave of obesity-related cancers with high aggressiveness and shortened latency. Observational studies have shown that from cancer risk to disease prognosis, an individual with obesity is consistently ranked worse compared to their lean counterpart. Mechanistic studies identified similar sets of abnormalities under obesity that may lead to cancer development, including ectopic fat storage, altered adipokine profiles, hormone fluctuations and meta-inflammation, but could not explain how these common mechanisms produce over 13 different cancer types. A major hurdle in the mechanistic underpinning of obesity-related cancer is the lack of suitable pre-clinical models that spontaneously develop obesity-linked cancers like humans. Current approaches and animal models fall short when discerning the confounders that often coexist in obesity. In this mini-review, we will briefly survey advances in the different obesity-linked cancers and discuss the challenges and limitations in the rodent models employed to study their relationship. We will also provide our perspectives on the future of obesity-linked cancer research.

Low-dose aspirin use and risk of contralateral breast cancer: a Danish nationwide cohort study

Observational studies of aspirin use and breast cancer risk have provided inconsistent results. The occurrence of contralateral breast cancer (CBC) among breast cancer survivors may serve as a useful high-risk model to identify preventive drug effects. Using this model, we examined the association between post-diagnosis use of low-dose aspirin and risk of CBC. We identified all women recorded with a first primary breast cancer in the Danish Breast Cancer Cooperative Group Database between 1996 and 2012. Information on drug use, tumor and patient characteristics, treatment, and CBC was obtained from nationwide registries. In the main analysis, we defined time-varying post-diagnosis low-dose aspirin use as two or more prescriptions filled during follow-up and applied a one-year exposure lag. Cox proportional hazard regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between post-diagnosis low-dose aspirin use and CBC risk. Among 52,723 breast cancer patients, 1,444 women developed CBC during a median follow-up of 4.8 years. The adjusted HR for CBC associated with post-diagnosis use of low-dose aspirin was 0.91 (95% CI: 0.75-1.09). We observed no substantial variation in HRs according to pattern of low-dose aspirin use or estrogen receptor status of the first or the contralateral breast cancer. In conclusion, this large nationwide cohort study of breast cancer survivors does not provide strong evidence suggesting an association between post-diagnosis use of low-dose aspirin and risk of CBC.

p-21 Activated Kinase as a Molecular Target for Chemoprevention in Diabetes

Hypothesis: Anti-diabetic drugs modulate p-21 activated kinase (PAK) signaling. Introduction: Type 2 diabetes mellitus (T2DM) is a chronic inflammatory disease associated with increased cancer risk. PAK signaling is implicated in cellular homeostasis when regulated, and cancer when unrestrained. Recent reports provided a role for PAK signaling in glucose homeostasis, but the role of PAKs in the pathogenesis of T2DM is unknown. Here, we performed a mini-meta-analysis to explore if anti-diabetic drugs modify PAK signaling pathways, and provide insight regarding modulation of these pathways, to potentially reduce diabetes-associated cancer risk. Methods: PAK interacting partners in T2DM were identified using the online STRING database. Correlation studies were performed via systematic literature review to understand the effect of anti-diabetic drugs on PAK signaling. A mini-meta-analysis correlated multiple clinical studies and revealed the overall clinical response rate and percentage of adverse events in piogliazone (n = 53) and metformin (n = 91) treated patients with PAK-associated diseases. Results: A total of 30 PAK interacting partners were identified (10: reduced beta-cell mass; 10: beta-cell dysfunction; 10: obesity-insulin resistance), which were highly associated with Wnt, and G-protein signaling. The anti-diabetic drug metformin activated signaling pathways upstream; whereas pioglitazone inhibited pathways downstream of PAK. Overall, clinical response upon pioglitazone treatment was 53%. Seventy-nine percent of pioglitazone and 75% of metformin treated patients had adverse events. Pioglitazone reduced molecular-PAK biomarkers of proliferation (Ki67 and CyclinD1), and metformin had the opposite effect. Conclusions: PAK signaling in T2DM likely involves Wnt and G-protein signaling, which may be altered by the anti-diabetic drugs metformin and pioglitazone. Apart from the therapeutic limitations of adverse events, pioglitazone may be promising in chemoprevention. However long-term multi-centered studies, which initiate pioglitazone treatment early will be required to fully assess the full potential of these drugs.

Effect of Aspirin on All-Cause Mortality in the Healthy Elderly

BACKGROUND

In the primary analysis of the Aspirin in Reducing Events in the Elderly (ASPREE) trial, now published in the Journal, we report that the daily use of aspirin did not provide a benefit with regard to the primary end point of disability-free survival among older adults. A numerically higher rate of the secondary end point of death from any cause was observed with aspirin than with placebo.

METHODS

From 2010 through 2014, we enrolled community-dwelling persons in Australia and the United States who were 70 years of age or older (or ≥65 years of age among blacks and Hispanics in the United States) and did not have cardiovascular disease, dementia, or disability. Participants were randomly assigned to receive 100 mg of enteric-coated aspirin or placebo. Deaths were classified according to the underlying cause by adjudicators who were unaware of trial-group assignments. Hazard ratios were calculated to compare mortality between the aspirin group and the placebo group, and post hoc exploratory analyses of specific causes of death were performed.

RESULTS

Of the 19,114 persons who were enrolled, 9525 were assigned to receive aspirin and 9589 to receive placebo. A total of 1052 deaths occurred during a median of 4.7 years of follow-up. The risk of death from any cause was 12.7 events per 1000 person-years in the aspirin group and 11.1 events per 1000 person-years in the placebo group (hazard ratio, 1.14; 95% confidence interval [CI], 1.01 to 1.29). Cancer was the major contributor to the higher mortality in the aspirin group, accounting for 1.6 excess deaths per 1000 person-years. Cancer-related death occurred in 3.1% of the participants in the aspirin group and in 2.3% of those in the placebo group (hazard ratio, 1.31; 95% CI, 1.10 to 1.56).

CONCLUSIONS

Higher all-cause mortality was observed among apparently healthy older adults who received daily aspirin than among those who received placebo and was attributed primarily to cancer-related death. In the context of previous studies, this result was unexpected and should be interpreted with caution. (Funded by the National Institute on Aging and others; ASPREE ClinicalTrials.gov number, NCT01038583 .).

Current approaches to immunotherapy in noncolorectal gastrointestinal malignancies

Noncolorectal gastrointestinal (GI) malignancies are among the most frequently diagnosed cancers. Despite the undeniable progress in systemic treatments in recent decades, further improvements using cytotoxic chemotherapy seem unlikely. In this setting, recent discoveries regarding the mechanism underlying immune evasion have prompted the study of molecules capable of inducing strong antitumor responses. Thus, according to early data, immunotherapy is a very promising tool for the treatment of patients with GI malignancies. Noncolorectal GI cancers are a major public health problem worldwide. Traditional treatment options, such as chemotherapy, surgery, radiation therapy, monoclonal antibodies and antiangiogenic agents, have been the backbone of treatment for various stages of GI cancers, but overall mortality remains a major problem. Thus, there is a substantial unmet need for new drugs and therapies to further improve the outcomes of treatment for noncolorectal GI malignancies. "Next-generation" immunotherapy is emerging as an effective and promising treatment option in several types of cancers. Therefore, encouraged by this recent success, many clinical trials evaluating the efficacy of immune checkpoint inhibitors and other strategies in treating noncolorectal GI malignancies are ongoing. This review will summarize the current clinical progress of modern immunotherapy in the field of noncolorectal GI tumors.

The role of sphingosine-1-phosphate in inflammation and cancer progression

Many inflammatory mediators are involved in the process of carcinogenesis and cancer progression. In addition to cytokines and chemokines, lipid mediators have recently attracted attention as signaling molecules associated with inflammatory diseases. Sphingosine‐1‐phosphate (S1P) is a pleiotropic lipid mediator that regulates cell survival and migration, immune cell recruitment, angiogenesis and lymphangiogenesis. S1P also plays a significant role in inflammation and cancer. The gradation of S1P concentration in the blood, lymph and tissue regulates lymphocyte trafficking, an important component of inflammation. Furthermore, cancer cells produce elevated levels of S1P, contributing to the tumor microenvironment and linking cancer and inflammation. Future technological advances may reveal greater detail about the mechanisms of S1P regulation in the tumor microenvironment and the contribution of S1P to cancer progression. Considering the critical role of S1P in linking inflammation and cancer, it is possible that the S1P signaling pathway could be a novel therapeutic target for cancers with chronic inflammation.

Elimination of CD4lowHLA-G+ T cells overcomes castration-resistance in prostate cancer therapy

Androgen deprivation therapy (ADT) is a main treatment for prostate cancer (PCa) but the disease often recurs and becomes castration-resistant in nearly all patients. Recent data implicate the involvement of immune cells in the development of this castration-resistant prostate cancer (CRPC). In particular, T cells have been found to be expanded in both PCa patients and mouse models shortly after androgen deprivation. However, whether or which of the T cell subtypes play an important role during the development of CRPC is unknown. Here we identified a novel population of CD4^lowHLA-G⁺ T cells that undergo significant expansion in PCa patients after ADT. In mouse PCa models, a similar CD4^low T cell population expands during the early stages of CRPC onset. These cells are identified as IL-4-expressing T_H17 cells, and are shown to be associated with CRPC onset in patients and essential for the development of CRPC in mouse models. Mechanistically, CD4^lowHLA-G⁺ T cells drive androgen-independent growth of prostate cancer cells by modulating the activity and migration of CD11b^lowF4/80^hi macrophages. Furthermore, following androgen deprivation, elevated PGE₂-EP2 signaling inhibited the expression of CD4 in thymocytes, and subsequently induced the polarization of CD4^low naïve T cells towards the IL-4-expressing T_H17 phenotype via up-regulation of IL23R. Therapeutically, inactivating PGE₂ signaling with celecoxib at a time when CD4^lowHLA-G⁺ T cells appeared, but not immediately following androgen deprivation, dramatically suppressed the onset of CRPC. Collectively, our results indicate that an unusual population of CD4^lowHLA-G⁺ T cells is essential for the development of CRPC and point to a new therapeutic avenue of combining ADT with PGE₂ inhibition for the treatment of prostate cancer.

Oral hygiene might prevent cancer

Many evidences support that species from the Human Oral Microbiome Database such as Fusobacterium nucleatum or Bacteroides, linked previously to periodontitis and appendicitis, play a role in colorectal cancer (CRC), including metastasis. These typically oral species are invasive anaerobes that form biofilms in their virulent state. Aspirin (a NSAID) has been recently included into routine CRC prevention rationale. NSAIDs can prevent the growth of neoplastic lesions by inhibiting COX enzymes and another set of recently identified COX-independent targets, which include the WNT, AMPK and MTOR signaling pathways, the crosstalk between nucleoli and NF-κB transcriptional activity in apoptosis, and the biochemistry of platelets. These are signaling pathways related to tumor-promoting inflammation. In this process, pathogens or simple deregulation of the microbiota play an important role in CRC. Aspirin and other NSAIDs are efficient inhibitors of biofilm formation and able to control periodontitis development preventing inflammation related to the microbiota of the gingival tissue, so its seems plausible to include this pathway in the mechanisms that aspirin uses to prevent CRC. We propose arguments suggesting that current oral hygiene methods and other future developments against periodontitis might prevent CRC and probably other cancers, alone or in combination with other options; and that the multidisciplinary studies needed to prove this hypothesis might be relevant for cancer prevention.

Cancer Hallmarks Analytics Tool (CHAT): a text mining approach to organize and evaluate scientific literature on cancer

Motivation

To understand the molecular mechanisms involved in cancer development, significant efforts are being invested in cancer research. This has resulted in millions of scientific articles. An efficient and thorough review of the existing literature is crucially important to drive new research. This time-demanding task can be supported by emerging computational approaches based on text mining which offer a great opportunity to organize and retrieve the desired information efficiently from sizable databases. One way to organize existing knowledge on cancer is to utilize the widely accepted framework of the Hallmarks of Cancer. These hallmarks refer to the alterations in cell behaviour that characterize the cancer cell.

Results

We created an extensive Hallmarks of Cancer taxonomy and developed automatic text mining methodology and a tool (CHAT) capable of retrieving and organizing millions of cancer-related references from PubMed into the taxonomy. The efficiency and accuracy of the tool was evaluated intrinsically as well as extrinsically by case studies. The correlations identified by the tool show that it offers a great potential to organize and correctly classify cancer-related literature. Furthermore, the tool can be useful, for example, in identifying hallmarks associated with extrinsic factors, biomarkers and therapeutics targets.

Availability and implementation

CHAT can be accessed at: http://chat.lionproject.net. The corpus of hallmark-annotated PubMed abstracts and the software are available at: http://chat.lionproject.net/about

Supplementary information

Supplementary data are available at Bioinformatics online.

Clinically Relevant Anti-Inflammatory Agents for Chemoprevention of Colorectal Cancer: New Perspectives

Substantial efforts are underway for prevention of early stages or recurrence of colorectal cancers (CRC) or new polyp formation by chemoprevention strategies. Several epidemiological, clinical and preclinical studies to date have supported the chemopreventive potentials of several targeted drug classes including non-steroidal anti-inflammatory drugs (NSAIDs) (aspirin, naproxen, sulindac, celecoxib, and licofelone), statins and other natural agents—both individually, and in combinations. Most preclinical trials although were efficacious, only few agents entered clinical trials and have been proven to be potential chemopreventive agents for colon cancer. However, there are limitations for these agents that hinder their approval by the food and drug administration for chemoprevention use in high-risk individuals and in patients with early stages of CRC. In this review, we update the recent advancement in pre-clinical and clinical development of selected anti-inflammatory agents (aspirin, naproxen, sulindac, celecoxib, and licofelone) and their combinations for further development as novel colon cancer chemopreventive drugs. We provide further new perspectives from this old research, and insights into precision medicine strategies to overcome unwanted side-effects and overcoming strategies for colon cancer chemoprevention.

Regular aspirin use and gene expression profiles in prostate cancer patients

PURPOSE

Pharmacoepidemiology studies suggest prognostic benefits of aspirin in prostate cancer. We hypothesized that aspirin induces transcriptional changes in tumors or normal prostate tissue.

METHODS

We analyzed the prostatic transcriptome from men diagnosed with prostate cancer during follow-up of the Physicians' Health Study 1 (PHS, n = 149), initially a randomized controlled trial of aspirin. Aspirin target genes were identified through systematic literature review and a drug target database. We compared target gene expression according to regular aspirin use at cancer diagnosis and used whole-transcriptome gene set enrichment analysis to identify gene sets associated with aspirin use. Results were validated in the Health Professionals Follow-up Study (HPFS, n = 254) and in Connectivity Map.

RESULTS

Of 12 target genes identified from prior studies and 540 genes from the drug target database, none were associated with aspirin use. Twenty-one gene sets were enriched in tumor tissue of aspirin users, 18 of which were clustered around ribosome function and translation. These gene sets were associated with exposure to cyclooxygenase inhibitors in Connectivity Map. Their association with cancer prognosis was U-shaped in both cohorts. No gene sets were enriched in normal tissue. In HPFS, neither the target genes nor the gene sets were associated with aspirin use.

CONCLUSIONS

Regular aspirin use may affect ribosome function in prostate tumors. Other putative target genes had similar expression in tumors from aspirin users and non-users. If results are corroborated by experimental studies, a potential benefit of aspirin may be limited to a subset of prostate cancer patients.

Association Between Risk Factors for Colorectal Cancer and Risk of Serrated Polyps and Conventional Adenomas

BACKGROUND & AIMS

Serrated polyps (SPs) and conventional adenomas are precursor lesions for colorectal cancer (CRC), but they are believed to arise via distinct pathways. We characterized risk factor profiles for SPs and conventional adenomas in a post hoc analysis of data from 3 large prospective studies.

METHODS

We collected data from the Nurses' Health Study, the Nurses' Health Study 2, and the Health Professionals Follow-up Study on subjects who developed SPs or conventional adenomas. Our analysis comprised 141,143 participants who had undergone lower gastrointestinal endoscopy, provided updated diet and lifestyle data every 2-4 years, and were followed until diagnosis of a first polyp. We assessed 13 risk factors for CRC in patients with SPs or conventional adenomas and examined the associations according to histopathology features.

RESULTS

We documented 7945 SPs, 9212 conventional adenomas, and 2382 synchronous SPs and conventional adenomas during 18-20 years of follow-up. Smoking, body mass index, alcohol intake, family history of CRC, and height were associated with higher risk of SPs and conventional adenomas, whereas higher intake of vitamin D and marine omega-3 fatty acid were associated with lower risk. The associations tended to be stronger for synchronous SPs and conventional adenomas. Smoking, body mass index, and alcohol intake were more strongly associated with SPs than conventional adenomas (P for heterogeneity <.05), whereas physical activity and intake of total folate and calcium were inversely associated with conventional adenomas but not SPs. For SPs and conventional adenomas, the associations tended to be stronger for polyps in the distal colon and rectum, of 10 mm or larger or with advanced histology.

CONCLUSIONS

In an analysis of data from 3 large prospective studies, we found that although SPs and conventional adenomas share many risk factors, some factors are more strongly associated with one type of lesion than the other. These findings provide support for the etiologic heterogeneity of colorectal neoplasia.

Chemoprevention of Barrett's Esophagus and Esophageal Adenocarcinoma

Barrett's esophagus is common in Western countries, but progression to esophageal adenocarcinoma is uncommon. Chemoprevention therefore needs to consider whether benefits outweigh risks given an otherwise healthy population. This will depend on the particular population at risk and the relative safety of a potential preventive agent. Most evidence regarding the potential benefit of chemoprevention of Barrett's esophagus and prevention of progression to esophageal adenocarcinoma is based on observational studies such as case-control and cohort studies. Given the potential benefits and relatively low risks, patients with BE should receive once-daily PPI therapy, but routine use of twice-daily PPI is not recommended unless necessitated by poor control of reflux symptoms or esophagitis. Recent data suggest that the inverse associations between aspirin/NSAID use and esophageal adenocarcinoma may be the result of reducing neoplastic progression (from metaplasia to dysplasia and carcinoma) rather than initiation of Barrett's esophagus. While substantial associative data suggest a potential benefit of aspirin and nonaspirin NSAIDs in reducing the risk of progression of Barrett's esophagus, the low risk of progression and the potential risks (gastrointestinal bleeding, complicated ulcer disease, hemorrhagic stroke) do not warrant routine use, unless dictated by cardiovascular risk. Chemoprevention after mucosal ablation in those at highest risk of post-ablation recurrence (dysplastic Barrett's) is currently under investigation.

Precision Prevention and Early Detection of Cancer: Fundamental Principles

Prevention and early detection is critical for reducing the population cancer burden. Two approaches have been used: Population approaches change social norms (e.g., smoking bans) or impose incentives (e.g., cigarette taxes); high-risk strategies intervene upon individuals with elevated cancer risk (e.g., smoking cessation). Knowledge about carcinogenesis mechanisms, extreme exposures, and inherited susceptibility provides opportunities to develop precision prevention and early-detection (PPED) strategies. PPED aims to understand the basis of risk, identify groups that optimally benefit from interventions, characterize heterogeneity in intervention responses, optimize intervention timing, and minimize toxicities. We propose a framework around which PPED strategies can be developed. Currently available cancer prevention and early-detection approaches have the potential to reduce a large proportion of the cancer burden in the population. However, even if fully implemented, existing methods cannot fully eliminate the cancer burden. New PPED approaches that exploit the growing knowledge of molecular and biological cancer mechanisms should be developed and implemented. Cancer Discov; 8(7); 803-11. ©2018 AACR.

Integrative analysis of exogenous, endogenous, tumour and immune factors for precision medicine

Immunotherapy strategies targeting immune checkpoints such as the CTLA4 and CD274 (programmed cell death 1 ligand 1, PD-L1)/PDCD1 (programmed cell death 1, PD-1) T-cell coreceptor pathways are revolutionising oncology. The approval of pembrolizumab use for solid tumours with high-level microsatellite instability or mismatch repair deficiency by the US Food and Drug Administration highlights promise of precision immuno-oncology. However, despite evidence indicating influences of exogenous and endogenous factors such as diet, nutrients, alcohol, smoking, obesity, lifestyle, environmental exposures and microbiome on tumour-immune interactions, integrative analyses of those factors and immunity lag behind. Immune cell analyses in the tumour microenvironment have not adequately been integrated into large-scale studies. Addressing this gap, the transdisciplinary field of molecular pathological epidemiology (MPE) offers research frameworks to integrate tumour immunology into population health sciences, and link the exposures and germline genetics (eg, HLA genotypes) to tumour and immune characteristics. Multilevel research using bioinformatics, in vivo pathology and omics (genomics, epigenomics, transcriptomics, proteomics and metabolomics) technologies is possible with use of tissue, peripheral blood circulating cells, cell-free plasma, stool, sputum, urine and other body fluids. This immunology-MPE model can synergise with experimental immunology, microbiology and systems biology. GI neoplasms represent exemplary diseases for the immunology-MPE model, given rich microbiota and immune tissues of intestines, and the well-established carcinogenic role of intestinal inflammation. Proof-of-principle studies on colorectal cancer provided insights into immunomodulating effects of aspirin, vitamin D, inflammatory diets and omega-3 polyunsaturated fatty acids. The integrated immunology-MPE model can contribute to better understanding of environment-tumour-immune interactions, and effective immunoprevention and immunotherapy strategies for precision medicine.