Aspirin and colorectal cancer: the promise of precision chemoprevention

Hypoxia and Inflammation in Cancer, Focus on HIF and NF-κB

Cancer is often characterised by the presence of hypoxia and inflammation. Paramount to the mechanisms controlling cellular responses under such stress stimuli, are the transcription factor families of Hypoxia Inducible Factor (HIF) and Nuclear Factor of κ-light-chain-enhancer of activated B cells (NF-κB). Although, a detailed understating of how these transcription factors respond to their cognate stimulus is well established, it is now appreciated that HIF and NF-κB undergo extensive crosstalk, in particular in pathological situations such as cancer. Here, we focus on the current knowledge on how HIF is activated by inflammation and how NF-κB is modulated by hypoxia. We summarise the evidence for the possible mechanism behind this activation and how HIF and NF-κB function impacts cancer, focusing on colorectal, breast and lung cancer. We discuss possible new points of therapeutic intervention aiming to harness the current understanding of the HIF-NF-κB crosstalk.

Inhibition of HIF-1α by PX-478 suppresses tumor growth of esophageal squamous cell cancer in vitro and in vivo

The aim of this study is to investigate the clinical significance of hypoxia inducible factor-1α (HIF-1α) expression in esophageal squamous cell cancer (ESCC) and clarify the effects of PX-478, a selective HIF-1α inhibitor, on ESCC both in vitro and in vivo. HIF-1α, cyclooxygenase-2 (COX-2) and programmed death ligand-1 (PD-L1) were markedly overexpressed in ESCC tissue and associated with poorer survival. In vitro, both COX-2 and PD-L1 expression of ESCC cells were significantly induced by CoCl₂ treatment, but inhibited by HIF-1α knock-down or PX-478 treatment. Furthermore, PX-478 significantly inhibited tumor cell proliferation by inhibiting the G2/M transition and promoting apoptosis of ESCC cells. In addition, inhibited epithelial-mesenchymal transition was observed after PX-478 treatment. In vivo, PX-478 significantly decreased tumor volume following subcutaneous implantation. Together, our results indicated that PX-478 had significant antitumor activity against HIF-1α over-expressing ESCC tumors in vitro and in vivo. These results opened up the possibility of inhibiting HIF-1α for targeted therapy of ESCC.

Precancer Atlas to Drive Precision Prevention Trials

Cancer development is a complex process driven by inherited and acquired molecular and cellular alterations. Prevention is the holy grail of cancer elimination, but making this a reality will take a fundamental rethinking and deep understanding of premalignant biology. In this Perspective, we propose a national concerted effort to create a Precancer Atlas (PCA), integrating multi-omics and immunity - basic tenets of the neoplastic process. The biology of neoplasia caused by germline mutations has led to paradigm-changing precision prevention efforts, including: tumor testing for mismatch repair (MMR) deficiency in Lynch syndrome establishing a new paradigm, combinatorial chemoprevention efficacy in familial adenomatous polyposis (FAP), signal of benefit from imaging-based early detection research in high-germline risk for pancreatic neoplasia, elucidating early ontogeny in BRCA1-mutation carriers leading to an international breast cancer prevention trial, and insights into the intricate germline-somatic-immunity interaction landscape. Emerging genetic and pharmacologic (metformin) disruption of mitochondrial (mt) respiration increased autophagy to prevent cancer in a Li-Fraumeni mouse model (biology reproduced in clinical pilot) and revealed profound influences of subtle changes in mt DNA background variation on obesity, aging, and cancer risk. The elaborate communication between the immune system and neoplasia includes an increasingly complex cellular microenvironment and dynamic interactions between host genetics, environmental factors, and microbes in shaping the immune response. Cancer vaccines are in early murine and clinical precancer studies, building on the recent successes of immunotherapy and HPV vaccine immune prevention. Molecular monitoring in Barrett's esophagus to avoid overdiagnosis/treatment highlights an important PCA theme. Next generation sequencing (NGS) discovered age-related clonal hematopoiesis of indeterminate potential (CHIP). Ultra-deep NGS reports over the past year have redefined the premalignant landscape remarkably identifying tiny clones in the blood of up to 95% of women in their 50s, suggesting that potentially premalignant clones are ubiquitous. Similar data from eyelid skin and peritoneal and uterine lavage fluid provide unprecedented opportunities to dissect the earliest phases of stem/progenitor clonal (and microenvironment) evolution/diversity with new single-cell and liquid biopsy technologies. Cancer mutational signatures reflect exogenous or endogenous processes imprinted over time in precursors. Accelerating the prevention of cancer will require a large-scale, longitudinal effort, leveraging diverse disciplines (from genetics, biochemistry, and immunology to mathematics, computational biology, and engineering), initiatives, technologies, and models in developing an integrated multi-omics and immunity PCA - an immense national resource to interrogate, target, and intercept events that drive oncogenesis. Cancer Res; 77(7); 1510-41. ©2017 AACR.

Population-wide Impact of Long-term Use of Aspirin and the Risk for Cancer

IMPORTANCE

The US Preventive Services Task Force recently recommended the use of aspirin to prevent colorectal cancer and cardiovascular disease among many US adults. However, the association of aspirin use with the risk for other cancer types and the potential population-wide effect of aspirin use on cancer, particularly within the context of screening, remain uncertain.

OBJECTIVES

To examine the potential benefits of aspirin use for overall and subtype-specific cancer prevention at a range of doses and durations of use and to estimate the absolute benefit of aspirin in the context of screening.

DESIGN, SETTING, AND PARTICIPANTS

Two large US prospective cohort studies, the Nurses' Health Study (1980-2010) and Health Professionals Follow-up Study (1986-2012), followed up 135 965 health care professionals (88 084 women and 47 881 men, respectively) who reported on aspirin use biennially. The women were aged 30 to 55 years at enrollment in 1976; the men, aged 40 to 75 years in 1986. Final follow-up was completed on June 30, 2012, for the Nurses' Health Study cohort and January 31, 2010, for the Health Professionals Follow-up Study cohort, and data were accessed from September 15, 2014, to December 17, 2015.

MAIN OUTCOMES AND MEASURES

Relative risks (RRs) for incident cancers and population-attributable risk (PAR).

RESULTS

Among the 88 084 women and 47 881 men who underwent follow-up for as long as 32 years, 20 414 cancers among women and 7571 cancers among men were documented. Compared with nonregular use, regular aspirin use was associated with a lower risk for overall cancer (RR, 0.97; 95% CI, 0.94-0.99), which was primarily owing to a lower incidence of gastrointestinal tract cancers (RR, 0.85; 95% CI, 0.80-0.91), especially colorectal cancers (RR, 0.81; 95% CI, 0.75-0.88). The benefit of aspirin on gastrointestinal tract cancers appeared evident with the use of at least 0.5 to 1.5 standard aspirin tablets per week; the minimum duration of regular use associated with a lower risk was 6 years. Among individuals older than 50 years, regular aspirin use could prevent 33 colorectal cancers per 100 000 person-years (PAR, 17.0%) among those who had not undergone a lower endoscopy and 18 colorectal cancers per 100 000 person-years (PAR, 8.5%) among those who had. Regular aspirin use was not associated with the risk for breast, advanced prostate, or lung cancer.

CONCLUSIONS AND RELEVANCE

Long-term aspirin use was associated with a modest but significantly reduced risk for overall cancer, especially gastrointestinal tract tumors. Regular aspirin use may prevent a substantial proportion of colorectal cancers and complement the benefits of screening.

Molecular pathological epidemiology: new developing frontiers of big data science to study etiologies and pathogenesis

Molecular pathological epidemiology (MPE) is an integrative field that utilizes molecular pathology to incorporate interpersonal heterogeneity of a disease process into epidemiology. In each individual, the development and progression of a disease are determined by a unique combination of exogenous and endogenous factors, resulting in different molecular and pathological subtypes of the disease. Based on "the unique disease principle," the primary aim of MPE is to uncover an interactive relationship between a specific environmental exposure and disease subtypes in determining disease incidence and mortality. This MPE approach can provide etiologic and pathogenic insights, potentially contributing to precision medicine for personalized prevention and treatment. Although breast, prostate, lung, and colorectal cancers have been among the most commonly studied diseases, the MPE approach can be used to study any disease. In addition to molecular features, host immune status and microbiome profile likely affect a disease process, and thus serve as informative biomarkers. As such, further integration of several disciplines into MPE has been achieved (e.g., pharmaco-MPE, immuno-MPE, and microbial MPE), to provide novel insights into underlying etiologic mechanisms. With the advent of high-throughput sequencing technologies, available genomic and epigenomic data have expanded dramatically. The MPE approach can also provide a specific risk estimate for each disease subgroup, thereby enhancing the impact of genome-wide association studies on public health. In this article, we present recent progress of MPE, and discuss the importance of accounting for the disease heterogeneity in the era of big-data health science and precision medicine.

Tolfenamic acid-induced alterations in genes and pathways in pancreatic cancer cells

Non-steroidal anti-inflammatory drugs (NSAIDs) are being tested extensively for their role in the treatment and prevention of several cancers. Typically NSAIDs exhibit anti-tumor activities via modulation of cyclooxygenase (COX)-dependent mechanisms, however, an anti-cancer NSAID tolfenamic acid (TA) is believed to work through COX-independent pathways. Results from our laboratory and others have demonstrated the anti-cancer activity of TA in various cancer models including pancreatic cancer. TA has been shown to modulate certain cellular processes including, apoptosis, reactive oxygen species and signaling. In this study, molecular profiling was performed to precisely understand the mode of action of TA. Three pancreatic cancer cell lines, L3.6pl, MIA PaCa-2, and Panc1 were treated with TA (50 μM for 48 h) and the changes in gene expression was evaluated using the Affymetrix GeneChip Human Gene ST Array platform. Microarray results were further validated using quantitative PCR for seven genes altered by TA treatment in all three cell lines. Functional analysis of differentially expressed genes (2 fold increase or decrease, p < 0.05) using Ingenuity Pathway Analysis software, revealed that TA treatment predominantly affected the genes involved in cell cycle, cell growth and proliferation, and cell death and survival. Promoter analysis of the differentially expressed genes revealed that they are enriched for Sp1 binding sites, suggesting that Sp1 could be a major contributor in mediating the effect of TA. The gene expression studies identified new targets involved in TA's mode of action, while supporting the hypothesis about the association of Sp1 in TA mediated effects in pancreatic cancer.

Tailored Treatment of Colorectal Cancer: Surgical, Molecular, and Genetic Considerations

Colorectal cancer (CRC) is a complex cancer disease, and approximately 40% of the surgically cured patients will experience cancer recurrence within 5 years. During recent years, research has shown that CRC treatment should be tailored to the individual patient due to the wide variety of risk factors, genetic factors, and surgical complexity. In this review, we provide an overview of the considerations that are needed to provide an individualized, patient-tailored treatment. We emphasize the need to assess the predictors of CRC, and we summarize the latest research on CRC genetics and immunotherapy. Finally, we provide a summary of the significant variations in the colon and rectal anatomy that is important to consider in an individualized surgical approach. For the individual patient with CRC, a tailored treatment approach is needed in the preoperative, operative, and postoperative phase.

ASPirin Intervention for the REDuction of colorectal cancer risk (ASPIRED): a study protocol for a randomized controlled trial

BACKGROUND

Although aspirin is recommended for the prevention of colorectal cancer, the specific individuals for whom the benefits outweigh the risks are not clearly defined. Moreover, the precise mechanisms by which aspirin reduces the risk of cancer are unclear. We recently launched the ASPirin Intervention for the REDuction of colorectal cancer risk (ASPIRED) trial to address these uncertainties.

METHODS/DESIGN

ASPIRED is a prospective, double-blind, multidose, placebo-controlled, biomarker clinical trial of aspirin use in individuals previously diagnosed with colorectal adenoma. Individuals (n = 180) will be randomized in a 1:1:1 ratio to low-dose (81 mg/day) or standard-dose (325 mg/day) aspirin or placebo. At two study visits, participants will provide lifestyle, dietary and biometric data in addition to urine, saliva and blood specimens. Stool, grossly normal colorectal mucosal biopsies and cytology brushings will be collected during a flexible sigmoidoscopy without bowel preparation. The study will examine the effect of aspirin on urinary prostaglandin metabolites (PGE-M; primary endpoint), plasma inflammatory markers (macrophage inhibitory cytokine-1 (MIC-1)), colonic expression of transcription factor binding (transcription factor 7-like 2 (TCF7L2)), colonocyte gene expression, including hydroxyprostaglandin dehydrogenase 15-(NAD) (HPGD) and those that encode Wnt signaling proteins, colonic cellular nanocytology and oral and gut microbial composition and function.

DISCUSSION

Aspirin may prevent colorectal cancer through multiple, interrelated mechanisms. The ASPIRED trial will scrutinize these pathways and investigate putative mechanistically based risk-stratification biomarkers.

TRIAL REGISTRATION

This protocol is registered with the U.S. National Institutes of Health trial registry, ClinicalTrials.gov, under the identifier NCT02394769 . Registered on 16 March 2015.

Targeting cancer-related inflammation in the era of immunotherapy

Recent advances in cancer immunotherapy, particularly immune checkpoint blockade therapy have dramatically changed the therapeutic strategy against advanced malignancies. Still, only a subset of patients shows a good response to any single therapy. Moreover, it remains largely unsolved how we can maintain durable clinical responses, or how we can successfully treat a broader range of cancers by immunotherapy. Growing evidence suggests that the major barrier to more successful cancer immunotherapy is the tumour microenvironment (TME), where chronic inflammation has a predominant role in tumour survival and proliferation, angiogenesis and immunosuppression. Over the past decades, our understanding of cancer-related inflammation has significantly evolved, and now we have various therapeutic options tailored to the TME. These therapeutic strategies include inhibiting inflammatory mediators or their downstream signalling molecules, blocking the recruitment of myeloid cells, modulating immunosuppressive functions in myeloid cells and re-educating the TME. In this review, we discuss the role of cancer-related inflammation as a potential target in the era of immunotherapy.

Evaluation of the Effectiveness and Cost-Effectiveness of Personalized Surveillance After Colorectal Adenomatous Polypectomy

Lifetime risk of developing colorectal cancer is 5%, and 5-year survival at early stage is 92%. Individuals with precancerous lesions removed at primary screening are typically recommended surveillance colonoscopy. Because greater benefits are anticipated for those with higher risk of colorectal cancer, scope for risk-specific surveillance recommendations exists. This review assesses published cost-effectiveness estimates of postpolypectomy surveillance to consider the potential for personalized recommendations by risk group. Meta-analyses of incidence of advanced neoplasia postpolypectomy for low-risk cases were comparable to those without adenoma, with both rates under the lifetime risk of 5%. This group may not benefit from intensive surveillance, which risks unnecessary harm and inefficient use of often scarce colonoscopy capacity. Therefore, greater personalization through deintensified strategies for low-risk individuals could be beneficial. The potential for noninvasive testing, such as fecal immunochemical tests, combined with primary prevention or chemoprevention may reserve colonoscopy for targeted use in personalized risk-stratified surveillance. This review appraised evidence supporting a program of personalized surveillance in patients with colorectal adenoma according to risk group and compared the effectiveness of surveillance colonoscopy with alternative prevention strategies. It assessed trade-offs among costs, benefits, and adverse effects that must be considered in a decision to adopt or reject personalized surveillance.

Chemoprevention of colorectal cancer in individuals with previous colorectal neoplasia: systematic review and network meta-analysis

OBJECTIVE

 To assess the comparative efficacy and safety of candidate agents (low and high dose aspirin, non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs), calcium, vitamin D, folic acid, alone or in combination) for prevention of advanced metachronous neoplasia (that is, occurring at different times after resection of initial neoplasia) in individuals with previous colorectal neoplasia, through a systematic review and network meta-analysis.

DATA SOURCES

 Medline, Embase, Web of Science, from inception to 15 October 2015; clinical trial registries.

STUDY SELECTION

 Randomized controlled trials in adults with previous colorectal neoplasia, treated with candidate chemoprevention agents, and compared with placebo or another candidate agent. Primary efficacy outcome was risk of advanced metachronous neoplasia; safety outcome was serious adverse events.

DATA EXTRACTION

 Two investigators identified studies and abstracted data. A Bayesian network meta-analysis was performed and relative ranking of agents was assessed with surface under the cumulative ranking (SUCRA) probabilities (ranging from 1, indicating that the treatment has a high likelihood to be best, to 0, indicating the treatment has a high likelihood to be worst). Quality of evidence was appraised with GRADE criteria.

RESULTS

 15 randomized controlled trials (12 234 patients) comparing 10 different strategies were included. Compared with placebo, non-aspirin NSAIDs were ranked best for preventing advanced metachronous neoplasia (odds ratio 0.37, 95% credible interval 0.24 to 0.53; SUCRA=0.98; high quality evidence), followed by low-dose aspirin (0.71, 0.41 to 1.23; SUCRA=0.67; low quality evidence). Low dose aspirin, however, was ranked the safest among chemoprevention agents (0.78, 0.43 to 1.38; SUCRA=0.84), whereas non-aspirin NSAIDs (1.23, 0.95 to 1.64; SUCRA=0.26) were ranked low for safety. High dose aspirin was comparable with low dose aspirin in efficacy (1.12, 0.59 to 2.10; SUCRA=0.58) but had an inferior safety profile (SUCRA=0.51). Efficacy of agents for reducing metachronous colorectal cancer could not be estimated.

CONCLUSIONS

 Among individuals with previous colorectal neoplasia, non-aspirin NSAIDs are the most effective agents for the prevention of advanced metachronous neoplasia, whereas low dose aspirin has the most favorable risk:benefit profile.

REGISTRATION

 PROSPERO (CRD42015029598).

Regular Aspirin Use Associates With Lower Risk of Colorectal Cancers With Low Numbers of Tumor-Infiltrating Lymphocytes

BACKGROUND & AIMS

Aspirin use reduces colorectal cancer risk. Aspirin, a nonsteroidal anti-inflammatory drug, inhibits prostaglandin-endoperoxide synthase 2 (PTGS2 or cyclooxygenase-2); PTGS2 promotes inflammation and suppresses T-cell-mediated adaptive immunity. We investigated whether the inverse association of aspirin use with colorectal carcinoma risk was stronger for tumors with lower degrees of lymphocytic infiltrates than for tumors with higher degrees of lymphocytic infiltrates.

METHODS

We collected aspirin use data biennially from participants in the Nurses' Health Study and Health Professionals Follow-up Study. Participants were asked whether they took aspirin in most weeks, the number of tablets taken per week, and years of aspirin use. We collected available tumor specimens (n = 1458) from pathology laboratories in the United States. A pathologist confirmed the diagnosis of colorectal adenocarcinoma (excluding anal squamous cell carcinoma), and evaluated histopathology features, including patterns and degrees of lymphocytic infiltrates within and around tumor areas. Person-years of follow-up evaluation were accrued from the date of return of questionnaires until dates of colorectal cancer diagnosis, death, or the end of follow-up evaluation (June 2010). Duplication-method Cox proportional hazards regression was used to assess the association of aspirin with the incidence of colorectal carcinoma subgroups according to the degree of tumor-infiltrating lymphocytes (TILs), intratumoral periglandular reaction, peritumoral reaction, or Crohn's-like reaction.

RESULTS

We documented 1458 rectal and colon cancers. The inverse association between regular aspirin use and colorectal cancer risk significantly differed by concentrations of TILs (P_{heterogeneity} = .007). Compared with nonregular use, regular aspirin use was associated with a lower risk of tumors that had low levels of TILs (relative risk, 0.72; 95% confidence interval, 0.63-0.81), and strength of the association depended on aspirin dose and duration (both P_trend < .001). In contrast, aspirin use was not associated with a risk of tumors having intermediate or high levels of TILs. This differential association was consistent regardless of the status of tumor microsatellite instability, mutations in BRAF, or expression of PTGS2. Regular aspirin use was associated with a lower risk of tumors that contained low levels of CD3⁺ T cells, CD8⁺ T cells, or CD45RO (PTPRC)⁺ T cells (measured by immunohistochemistry and computer-assisted image analysis).

CONCLUSIONS

Based on data from the prospective cohort studies, regular use of aspirin is associated with a lower risk of colorectal carcinomas with low concentrations of TILs. These findings indicate that the immune response in the tumor microenvironment could be involved in the chemopreventive effects of aspirin.

Reproductive history and risk of colorectal adenocarcinoma in parous women: a Nordic population-based case-control study

Background:

Data are conflicting regarding the role of endogenous sex hormones in colorectal carcinogenesis. In this large population-based study, we pooled data from birth and cancer registries in four Nordic countries, to evaluate the risk of colorectal adenocarcinoma in relation to women's reproductive history.

Methods:

We conducted a population-based case–control study among women registered in Nordic birth registries. The study included colorectal adenocarcinoma cases diagnosed in Denmark, Finland, Norway, and Sweden during 1967–2013 and up to 10 matched controls per case, in total 22 185 cases and 220 246 controls. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were derived from conditional logistic regression models. We had limited information available on possible confounders.

Results:

We found no evidence for associations between colorectal adenocarcinoma and parity, age at first and last birth, and time since first and last birth. The risk estimates were also close to unity for specific cancer subsites (proximal and distal colon and rectum). As well, when the analyses were stratified on menopausal status, parity, and mother's year of birth, no indication of associations was found.

Conclusions:

In this large, Nordic population-based study, no evidence for associations was found between women's reproductive history and colorectal adenocarcinoma in parous women.

Genetic predisposition to colorectal cancer: Implications for treatment and prevention

Colorectal cancer (CRC) is the third most common cancer diagnosed in men and women and approximately 5% of cases are associated with identifiable germline mutations associated with hereditary cancer syndromes. Lifetime risks for CRC can approach 50%-80% for mutation carriers in the absence of endoscopic and/or surgical intervention, and early identification of at-risk individuals can guide clinical interventions for cancer prevention and treatment. Personal and family history and molecular phenotype of CRC tumors are used in determining which patients should be referred for clinical genetic evaluation. Outcomes of genetic testing performed using next-generation sequencing (NGS) multigene panels suggest there can be significant overlap in clinical features among the various hereditary cancer syndromes. This review summarizes new developments in diagnosis and management of patients with genetic predisposition to CRC.

Aspirin in pancreatic cancer: chemopreventive effects and therapeutic potentials

Pancreatic cancer is one of the most aggressive malignancies with dismal prognosis. Recently, aspirin has been found to be an effective chemopreventive agent for many solid tumors. However, the function of aspirin use in pancreatic cancer largely remains unknown. We herein argued that aspirin could also lower the risk of pancreatic cancer. Importantly, aspirin assumes pleiotropic effects by targeting multiple molecules. It could further target the unique tumor biology of pancreatic cancer and modify the cancer microenvironment, thus showing remarkable therapeutic potentials. Besides, aspirin could reverse the chemoradiation resistance by repressing tumor repopulation and exert synergistic potentials with metformin on pancreatic cancer chemoprevention. Moreover, aspirin secondarily benefits pancreatic cancer patients through modestly reducing cancer pain and the risk of venous thromboembolism. Furthermore, new aspirin derivatives and delivery systems might help to improve risk-to-benefit ratio. In brief, aspirin is a promising chemopreventive agent and exerts significant therapeutic potentials in pancreatic cancer.

Low-dose aspirin or other nonsteroidal anti-inflammatory drug use and prostate cancer risk: a nationwide study

PURPOSE

Increasing evidence suggests that aspirin use may protect against prostate cancer. In a nationwide case-control study, using Danish high-quality registry data, we evaluated the association between the use of low-dose aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) and the risk of prostate cancer.

METHODS

We identified 35,600 patients (cases) with histologically verified prostate cancer during 2000-2012. Cases were matched to 177,992 population controls on age and residence by risk-set sampling. Aspirin and nonaspirin NSAID exposure was defined by type, estimated dose, duration, and consistency of use. We used conditional logistic regression to estimate odds ratios (ORs), with 95 % confidence intervals (CIs), for prostate cancer associated with low-dose aspirin (75-150 mg) or nonaspirin NSAID use, adjusted for potential confounders.

RESULTS

Use of low-dose aspirin was associated with an OR for prostate cancer of 0.94 (95 % CI 0.91-0.97). Slightly lower ORs were seen with increasing cumulative amount, duration, and consistency of low-dose aspirin use (continuous use, ≥5 years: OR 0.89; 95 % CI 0.82-0.97; ≥10 years: OR 0.86; 95 % CI 0.70-1.06). Nonaspirin NSAID use was associated with a slightly increased OR for prostate cancer (1.13; 95 % CI 1.10-1.15); however, this association was confined to localized disease and did not vary materially with amount, duration, or consistency of nonaspirin NSAID use.

CONCLUSIONS

Our study indicates that long-term, consistent low-dose aspirin use may provide modest protection against prostate cancer. The slightly increased risk of only localized prostate cancer with nonaspirin NSAID use suggests a noncausal explanation of the observed association.

Cancer Prevention and Interception: A New Era for Chemopreventive Approaches

At several recent, internationally attended scientific meetings, including the American Association for Cancer Research (AACR)'s "Shaping the Future of Cancer Prevention: A Roadmap for Integrative Cancer Science and Public Health" summit in Leesburg (VA) and the AACR Annual Meeting in New Orleans, the focus on cancer prevention to reduce cancer-related deaths was extensively discussed with renewed attention and emphasis. Cancer prevention should be actively proposed even to healthy individuals, and not just to individuals with high cancer risk. We discuss evaluation of a high cancer risk versus the relatively low risk for side effects of chemopreventive agents. The concept of cancer interception, which is halting transformed cells from becoming malignant cancers, should be adopted for cancer prevention. Potential prevention/interception actions include adopting healthy life style and avoiding carcinogens, repressing inflammation and pathologic angiogenesis, controlling metabolism, correcting insulin resistance and other metabolic alterations. Current drugs with limited toxicity can be repurposed to reduce cancer incidence. Aspirin is now being recommended for the prevention of colorectal cancer and it prevents other neoplasms as well. Metformin and β-blockers could be valuable for reducing pancreatic and breast cancer onset. On the basis of the evaluation of cancer risk, we here call for personalized approaches for cancer prevention and preventive interception and we envisage a list of measures and potential guidelines for preventive and interceptive strategies to reduce cancer burden. Investment into translational research to bring these approaches into public health policies and in the clinic is urgently needed. Clin Cancer Res; 22(17); 4322-7. ©2016 AACR.

GUCY2C ligand replacement to prevent colorectal cancer

Despite advances in screening and prevention strategies, colorectal cancer (CRC) remains the second-leading cause of cancer-related death in the United States. Given this continued public health burden of CRC, there is a clear need for improved disease prevention. CRC initiates and progresses over decades, canonically proceeding via a series of stepwise molecular events that turn a normal epithelium into a dysfunctional epithelium, then subsequently into an adenoma, and finally an invasive adenocarcinoma. An emerging paradigm suggests that guanylyl cyclase C (GUCY2C) functions as a tumor suppressor in the intestine, and that the loss of hormone ligands for this receptor causes epithelial dysfunction and represents an important step in the disease process. In that context, GUCY2C ligand replacement therapy has been proposed as a strategy to prevent colorectal cancer, a translational opportunity that is underscored by the recent regulatory approval of the oral GUCY2C ligand linaclotide (Linzess™, Forest Laboratories and Ironwood Pharmaceuticals, Inc.).

Roles of NF-κB in Cancer and Inflammatory Diseases and Their Therapeutic Approaches

Nuclear factor-κB (NF-κB) is a transcription factor that plays a crucial role in various biological processes, including immune response, inflammation, cell growth and survival, and development. NF-κB is critical for human health, and aberrant NF-κB activation contributes to development of various autoimmune, inflammatory and malignant disorders including rheumatoid arthritis, atherosclerosis, inflammatory bowel diseases, multiple sclerosis and malignant tumors. Thus, inhibiting NF-κB signaling has potential therapeutic applications in cancer and inflammatory diseases.