Aspirin use after diagnosis improves survival in older adults with colon cancer: a retrospective cohort study

Exploring the Protective Role of Aspirin Use in Mitigating Colorectal Cancer (CRC) Metastasis: A Nationwide Analysis (2016 to 2020)

Despite advancements in treatment strategies, the mortality from colorectal cancer (CRC) remains high. Evidence suggests that aspirin (ASA) may have a protective effect on CRC incidence and metastasis through various mechanisms. The 2016 to 2020 National Inpatient Sample was used to identify adult patients (age above 18 y) with the principal diagnosis of CRC. Patients were stratified into 2 groups based on ASA use. The outcomes studied were in-hospital mortality and rates of total, gastrointestinal (GI), non-GI, and lymphoid metastasis. A multivariate logistic regression analysis was performed to evaluate the impact of ASA use on outcomes after adjusting for patient demographics, comorbidities, and the Elixhauser Comorbidity Index (ECI). Of the 814,270 patients, 88,620 (10.8%) used ASA, with the majority being aged above 65 years (78%), male (57%), white (77.6%), and had Medicare insurance (74.5%). There was a higher prevalence of Diabetes mellitus, Hypertension, Chronic pulmonary disease, Coronary artery disease, Chronic kidney disease, Chronic heart failure, Obesity, and Smoking among aspirin users than among non-ASA users. Patients who used ASA had a lower prevalence of total (47.3% vs. 32.5%, P<0.001), GI (22.2% vs. 32.4%, P<0.001), non-GI (9.9% vs. 15.3%, P<0.001), and lymphoid (9.3% vs. 10.9%, P<0.001) metastasis compared with those who did not use ASA. After adjusting for confounding factors, patients with ASA use had lower odds of total (aOR: 0.75, 95% CI: 0.72-0.78, P<0.001), GI (aOR: 0.74, 95% CI: 0.71-0.77, P<0.001), non-GI (aOR: 0.72, 95% CI: 0.68-0.77, P<0.1), and statistically insignificant odds of lymphoid (aOR: 0.95, 95% CI: 0.90-1.00, P=0.098) metastasis. The use of ASA is associated with a decrease in the prevalence of metastasis among individuals diagnosed with CRC, but additional studies are required to elucidate the mechanism and duration of therapy needed to be effective.

Overcoming Chemotherapy Resistance in Metastatic Cancer: A Comprehensive Review

The management of metastatic cancer is complicated by chemotherapy resistance. This manuscript provides a comprehensive academic review of strategies to overcome chemotherapy resistance in metastatic cancer. The manuscript presents background information on chemotherapy resistance in metastatic cancer cells, highlighting its clinical significance and the current challenges associated with using chemotherapy to treat metastatic cancer. The manuscript delves into the molecular mechanisms underlying chemotherapy resistance in subsequent sections. It discusses the genetic alterations, mutations, and epigenetic modifications that contribute to the development of resistance. Additionally, the role of altered drug metabolism and efflux mechanisms, as well as the activation of survival pathways and evasion of cell death, are explored in detail. The strategies to overcome chemotherapy resistance are thoroughly examined, covering various approaches that have shown promise. These include combination therapy approaches, targeted therapies, immunotherapeutic strategies, and the repurposing of existing drugs. Each strategy is discussed in terms of its rationale and potential effectiveness. Strategies for early detection and monitoring of chemotherapy drug resistance, rational drug design vis-a-vis personalized medicine approaches, the role of predictive biomarkers in guiding treatment decisions, and the importance of lifestyle modifications and supportive therapies in improving treatment outcomes are discussed. Lastly, the manuscript outlines the clinical implications of the discussed strategies. It provides insights into ongoing clinical trials and emerging therapies that address chemotherapy resistance in metastatic cancer cells. The manuscript also explores the challenges and opportunities in translating laboratory findings into clinical practice and identifies potential future directions and novel therapeutic avenues. This comprehensive review provides a detailed analysis of strategies to overcome chemotherapy resistance in metastatic cancer. It emphasizes the importance of understanding the molecular mechanisms underlying resistance and presents a range of approaches for addressing this critical issue in treating metastatic cancer.

Repurposing approved non-oncology drugs for cancer therapy: a comprehensive review of mechanisms, efficacy, and clinical prospects

Cancer poses a significant global health challenge, with predictions of increasing prevalence in the coming years due to limited prevention, late diagnosis, and inadequate success with current therapies. In addition, the high cost of new anti-cancer drugs creates barriers in meeting the medical needs of cancer patients, especially in developing countries. The lengthy and costly process of developing novel drugs further hinders drug discovery and clinical implementation. Therefore, there has been a growing interest in repurposing approved drugs for other diseases to address the urgent need for effective cancer treatments. The aim of this comprehensive review is to provide an overview of the potential of approved non-oncology drugs as therapeutic options for cancer treatment. These drugs come from various chemotherapeutic classes, including antimalarials, antibiotics, antivirals, anti-inflammatory drugs, and antifungals, and have demonstrated significant antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties. A systematic review of the literature was conducted to identify relevant studies on the repurposing of approved non-oncology drugs for cancer therapy. Various electronic databases, such as PubMed, Scopus, and Google Scholar, were searched using appropriate keywords. Studies focusing on the therapeutic potential, mechanisms of action, efficacy, and clinical prospects of repurposed drugs in cancer treatment were included in the analysis. The review highlights the promising outcomes of repurposing approved non-oncology drugs for cancer therapy. Drugs belonging to different therapeutic classes have demonstrated notable antitumor effects, including inhibiting cell proliferation, promoting apoptosis, modulating the immune response, and suppressing metastasis. These findings suggest the potential of these repurposed drugs as effective therapeutic approaches in cancer treatment. Repurposing approved non-oncology drugs provides a promising strategy for addressing the urgent need for effective and accessible cancer treatments. The diverse classes of repurposed drugs, with their demonstrated antiproliferative, pro-apoptotic, immunomodulatory, and antimetastatic properties, offer new avenues for cancer therapy. Further research and clinical trials are warranted to explore the full potential of these repurposed drugs and optimize their use in treating various cancer types. Repurposing approved drugs can significantly expedite the process of identifying effective treatments and improve patient outcomes in a cost-effective manner.

Repurposing Drugs in Small Animal Oncology

Repurposing drugs in oncology consists of using off-label drugs that are licensed for various non-oncological medical conditions to treat cancer. Repurposing drugs has the advantage of using drugs that are already commercialized, with known mechanisms of action, proven safety profiles, and known toxicology, pharmacokinetics and pharmacodynamics, and posology. These drugs are usually cheaper than new anti-cancer drugs and thus more affordable, even in low-income countries. The interest in repurposed anti-cancer drugs has led to numerous in vivo and in vitro studies, with some promising results. Some randomized clinical trials have also been performed in humans, with certain drugs showing some degree of clinical efficacy, but the true clinical benefit for most of these drugs remains unknown. Repurposing drugs in veterinary oncology is a very new concept and only a few studies have been published so far. In this review, we summarize both the benefits and challenges of using repurposed anti-cancer drugs; we report and discuss the most relevant studies that have been previously published in small animal oncology, and we suggest potential drugs that could be clinically investigated for anti-cancer treatment in dogs and cats.

Drug Repurposing, a Fast-Track Approach to Develop Effective Treatments for Glioblastoma

Glioblastoma (GBM) remains one of the most difficult tumors to treat. The mean overall survival rate of 15 months and the 5-year survival rate of 5% have not significantly changed for almost 2 decades. Despite progress in understanding the pathophysiology of the disease, no new effective treatments to combine with radiation therapy after surgical tumor debulking have become available since the introduction of temozolomide in 1999. One of the main reasons for this is the scarcity of compounds that cross the blood-brain barrier (BBB) and reach the brain tumor tissue in therapeutically effective concentrations. In this review, we focus on the role of the BBB and its importance in developing brain tumor treatments. Moreover, we discuss drug repurposing, a drug discovery approach to identify potential effective candidates with optimal pharmacokinetic profiles for central nervous system (CNS) penetration and that allows rapid implementation in clinical trials. Additionally, we provide an overview of repurposed candidate drug currently being investigated in GBM at the preclinical and clinical levels. Finally, we highlight the importance of phase 0 trials to confirm tumor drug exposure and we discuss emerging drug delivery technologies as an alternative route to maximize therapeutic efficacy of repurposed candidate drug.

A Postsurgical Prognostic Nomogram for Locally Advanced Rectosigmoid Cancer to Assist in Patient Selection for Adjuvant Chemotherapy

Background

The perioperative treatment model for locally advanced rectosigmoid junction cancer (LARSC) has not been finalized; whether this model should refer to the treatment model for rectal cancer remains controversial.

Methods

We screened 10,188 patients with stage II/III rectosigmoid junction adenocarcinoma who underwent surgery between 2004 and 2016 from the National Cancer Institute Surveillance, Epidemiology, and End Results database. Among them, 4,960 did not receive adjuvant chemotherapy, while 5,228 did receive adjuvant chemotherapy. Propensity score matching was used to balance the two groups for confounding factors, and the Kaplan-Meier method and log-rank test were used for survival analysis. Cox proportional hazards regression analysis was used to identify independent prognostic factors and build a predictive nomogram of survival for LARSC. X-tile software was used to divide the patients into three groups (low, medium, and high) according to their risk scores. 726 patients in our hospital were included for external validation.

Results

LARSC patients did not show a benefit from neoadjuvant radiotherapy (P>0.05). After further excluding patients who received neoadjuvant radiotherapy, multivariate analysis found that age, grade, tumor size, T stage, and log odds of positive lymph nodes were independent prognostic factors for patients without adjuvant chemotherapy and were included in the nomogram. The C-index of the model was 0.690 (95% confidence interval: 0.668–0.712). We divided the patients into low, moderate, and high risk subgroups based on prediction scores of the nomogram. We found that adjuvant chemotherapy did not improve the prognosis of low risk patients, while moderate and high risk patients benefited from adjuvant therapy. External validation data found that moderate, and high risk patients also benefited from AT.

Conclusion

Direct surgery plus adjuvant chemotherapy may be the best perioperative treatment for LARSC. Moreover, adjuvant chemotherapy is only recommended for moderate and high risk patients as it did not benefit low risk patients.

Timing of Aspirin Use Among Patients With Colorectal Cancer in Relation to Mortality: A Systematic Review and Meta-Analysis

Background

Exposure of aspirin has been associated with reduced risk of colorectal cancer (CRC) incidence, but aspirin use in relation to CRC patients' mortality remains undetermined. It is necessary to quantify the association between aspirin use and CRC mortality.

Methods

Two authors independently searched the electronic databases (PubMed, Embase, and the Cochrane Library) from 1947 through April 25, 2020. All observational studies assessing the association between different timing of aspirin use and CRC mortality were included. The effect size on study outcomes was calculated using random-effect model and presented as risk ratio (RR) with 95% confidence interval (CI). Heterogeneity, publication bias, and quality of included studies were also assessed.

Results

A total of 34 studies were included in this systematic review and meta-analysis. Prediagnosis aspirin use was not associated with CRC-specific mortality (RR = 0.91, 95% CI = 0.79 to 1.05) and all-cause mortality (RR = 0.87, 95% CI = 0.57 to 1.31). A statistically significant association between continued aspirin use and improvement in both CRC-specific mortality (RR = 0.76, 95% CI = 0.70 to 0.81) and all-cause mortality (RR = 0.83, 95% CI = 0.74 to 0.93) was observed. Postdiagnosis use of aspirin was associated only with reduced all-cause mortality (RR = 0.80, 95% CI = 0.69 to 0.94).

Conclusions

Continued aspirin use before and after CRC diagnosis has the most advantage regarding the improvement of CRC mortality. Nevertheless, further prospective trials and mechanistic studies are highly warranted.

Current Studies of Aspirin as an Anticancer Agent and Strategies to Strengthen its Therapeutic Application in Cancer

Aspirin has emerged as a promising intervention in cancer in the past decade. However, there are existing controversies regarding the anticancer properties of aspirin as its mechanism of action has not been clearly defined. In addition, the risk of bleeding in the gastrointestinal tract from aspirin is another consideration that requires medical and pharmaceutical scientists to work together to develop more potent and safe aspirin therapy in cancer. This review presents the most recent studies of aspirin with regard to its role in cancer prevention and treatment demonstrated by highlighted clinical trials, mechanisms of action as well as approaches to develop aspirin therapy best beneficial to cancer patients. Hence, this review provides readers with an overview of aspirin research in cancer that covers not only the unique features of aspirin, which differentiate aspirin from other non-steroidal anti-inflammatory drugs (NSAIDs), but also strategies that can be used in the development of drug delivery systems carrying aspirin for cancer management. These studies convey optimistic messages on the continuing efforts of the scientist on the way of developing an effective therapy for patients with a low response to current cancer treatments.

Integration of genetic variants and gene network for drug repurposing in colorectal cancer

Even though many genetic risk loci for human diseases have been identified and comprehensively cataloged, strategies to guide clinical research by integrating the extensive results of genetic studies and biological resources are still limited. Moreover, integrative analyses that provide novel insights into disease biology are expected to be especially useful for drug discovery. Herein, we used text mining of genetic studies on colorectal cancer (CRC) and assigned biological annotations to identified risk genes in order to discover novel drug targets and potential drugs for repurposing. Risk genes for CRC were obtained from PubMed text mining, and for each gene, six functional and bioinformatic annotations were analyzed. The annotations include missense mutations, cis-expression quantitative trait loci (cis-eQTL), molecular pathway analyses, protein-protein interactions (PPIs), a genetic overlap with knockout mouse phenotypes, and primary immunodeficiency (PID). We then prioritized the biological risk candidate genes according to a scoring system of the six functional annotations. Each functional annotation was assigned one point, and those genes with a score ≥2 were designated "biological CRC risk genes". Using this method, we revealed 82 biological CRC risk genes, which were mapped to 128 genes in an expanded PPI network. Further utilizing DrugBank and the Therapeutic Target Database, we found 21 genes in our list that are targeted by 166 candidate drugs. Based on data from ClinicalTrials.gov and literature review, we found four known target genes with six drugs for clinical treatment in CRC, and three target genes with nine drugs supported by previous preclinical results in CRC. Additionally, 12 genes are targeted by 32 drugs approved for other indications, which can possibly be repurposed for CRC treatment. Finally, analysis from Connectivity Map (CMap) showed that 18 drugs have a high potential for CRC.

Lactobacilli and bifidobacteria derived from infant intestines may activate macrophages and lead to different IL-10 secretion

In this study, three strains of lactobacilli and bifidobacteria originally isolated from healthy infants, were tested for their abilities to activate RAW264.7 cells. Gene expression and cytokine production of interleukin-10 (IL-10) of RAW264.7 cells were evaluated. The activation of extracellular regulated protein kinases 1/2 (ERK1/2), p38, and nuclear factor-κB (NK-κB) were also assessed. These results suggest lactobacilli and bifidobacteria in infants may promote production of IL-10 in macrophages, conferring a protective effect in hosts suffering from inflammation. Dimerization of TLR2 and MyD88 and subsequent phosphorylation of the key downstream signaling molecules, such as MAPKs and NK-κB, may be one of the key underlying mechanisms of activation of macrophages by these microbes. Bifidobacteria and lactobacilli induced macrophages to secrete IL-10 in a different manner, which may relate to their abilities to activate key signaling pathways mediated by TLR2 and MyD88.

Challenges of improving treatment outcomes for colorectal and anal cancers in Japan: the Colorectal Cancer Study Group (CCSG) of the Japan Clinical Oncology Group (JCOG)

Colorectal cancer is a major public health concern in Japan. While early-stage colorectal adenocarcinoma treatment entails radical resection of the primary tumor, the importance of perioperative treatment is growing as physicians seek to further improve treatment outcomes. For anal squamous cell carcinoma, definitive chemoradiotherapy is superior to radical surgery in terms of improved patient quality of life. The Colorectal Cancer Study Group of the Japanese Clinical Oncology Group was established in 2001 and has worked to provide answers to common clinical questions and improve treatment outcomes for colorectal and anal cancers through 15 large-scale prospective clinical trials. Here, we discuss the current state of perioperative treatment for early-stage colon, rectal and anal cancers in Japan and approaches taken by the Colorectal Cancer Study Group/the Japanese Clinical Oncology Group to improve treatment outcomes for these cancers.

Efficacy of aspirin for stage III colorectal cancer: a randomized double-blind placebo-controlled trial (JCOG1503C, EPISODE-III trial)

Adjuvant chemotherapy is the current standard treatment for stage III colorectal cancer after curative resection. However, the prognosis of stage III colorectal cancer is still poor even after curative resection and adjuvant chemotherapy. Several observational studies suggested that the anti-tumor effect of aspirin. Therefore, we planned a randomized double-blind placebo-controlled phase III trial, which commenced in Japan in March 2018, to confirm the superiority of aspirin over placebo added to adjuvant chemotherapy in terms of disease-free survival (DFS) for stage III colorectal cancer patients after curative resection. A total of 880 patients will be accrued from 20 Japanese institutions within 3 years. The primary endpoint is DFS and the secondary endpoints are overall survival, relapse-free survival, relative dose intensity, adverse events, and serious adverse events. This trial has been registered at Japan Registry of Clinical Trials as jRCTs031180009 (https://jrct.niph.go.jp/detail/589).

Treatment of actinic keratosis through inhibition of cyclooxygenase-2: Potential mechanism of action of diclofenac sodium 3% in hyaluronic acid 2.5

Cyclooxygenase‐2 (COX‐2) and its metabolic product prostaglandin E₂ (PGE₂) are induced in response to growth factors, inflammatory cytokines, tumor promoters, activated oncogenes, and, in the skin, ultraviolet (UV) radiation. Accumulating evidence suggests a role for the COX‐2/PGE₂ pathway in tumorigenesis in various tissue types including cutaneous squamous cell carcinoma. There is also strong evidence for a role in the development of actinic keratoses (AKs) — common dysplastic lesions of the skin associated with UV radiation overexposure — considered as part of a continuum with skin cancer. Non‐steroidal anti‐inflammatory drugs (NSAIDs) exert their anti‐inflammatory, analgesic, and antipyretic effects by reversibly or irreversibly acetylating COX isoforms, inhibiting downstream prostaglandins, and may have a chemopreventive role in malignancies, including skin cancer. Topical treatment of AK lesions with the NSAID diclofenac sodium 3% in combination with hyaluronic acid 2.5% has been shown to be effective and well tolerated, although the mechanism of action remains to be elucidated.

Combined neutrophil/platelet/lymphocyte/differentiation score predicts chemosensitivity in advanced gastric cancer

Background

Gastric cancer is common in developing regions, and we hope to find out an economical but practical prognostic indicator. It was reported that pre-treatment peripheral neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR), as well as differentiation status, were associated with cancer progression. Hence, we introduced a novel combined Neutrophil/platelet/lymphocyte/differentiation Score (cNPLDS) to improve the prediction value of palliative chemotherapeutic response in advanced gastric cancer.

Methods

According to statistical sample size estimation, 136 primary diagnosed unresectable advanced ptaients were included for a retrospective study. The follow-up end-point was progression free survival (PFS) during the first-line palliative chemotherapy. Differentiation stratified patients into well, medium and poor groups by score 1 to 3, while patients with neither elevated NLR and PLR, only one elevated, or both elevated were of the combined NLR-PLR score (cNPS) 1 to 3, respectively. The cNPLDS was calculated by multiplying the tumor differentiation score and cNPS.

Results

Determined by the receiver operating characteristic (ROC) curve, the optimal cut-off points for NLR and PLR were 3.04 and 223. Through univariate analysis and survival analysis, poor differentiation, high NLR, high PLR, high cNPS, and high cNPLDS respectively indicated inferior PFS during the first-line palliative chemotherapy. Patients were furhter classified into low to high risk groups by cNPLDS. Groups of elevated NLR, PLR, cNPS, and cNPLDS showed lower disease control rate. Compared to other parameters, cNPLDS significantly improved the accuracy in predicing the first-progression.

Conclusions

This study indicates that the novel parameter cNPLDS is superior to NLR or PLR alone, or even cNPS, in predicting the first-line chemosensitivity in advanced gastric cancer.

Exploring clinicians' attitudes about using aspirin for risk reduction in people with Lynch Syndrome with no personal diagnosis of colorectal cancer

Recent research has shown that aspirin reduces the risk of cancers associated with Lynch Syndrome. However, uncertainty exists around the optimal dosage, treatment duration and whether the benefits of aspirin as a risk-reducing medication (RRM) outweigh adverse medication related side-effects. Little is known about clinicians' attitudes, current practice, and perceived barriers to recommending aspirin as a RRM. To explore the attitudes of clinicians who discuss risk management options with patients with Lynch Syndrome towards using aspirin as a RRM. Clinicians were invited through professional organisations to complete an online survey. Topics included their clinical experience with Lynch Syndrome, views and practice of recommending aspirin as a RRM, and knowledge about clinical risk management guidelines for Lynch Syndrome. Comparison of attitudes was made between three professional groups. 181 respondents were included in the analysis: 59 genetics professionals (genetic counsellors and clinical geneticists, medical oncologists with specialist training in familial cancer), 49 gastroenterologists and 73 colorectal surgeons. Most clinicians (76 %) considered aspirin to be an effective RRM and most (72 %) were confident about discussing it. In all professional categories, those who were confident about discussing aspirin with patients perceived it to be an effective RRM (OR = 2.8 [95 % CI = 1.8-4.2], p < 0.001). Eighty percent (47/59) of genetics professionals reported having discussed the use of aspirin with Lynch Syndrome patients compared to 69 % of gastroenterologists and 68 % of colorectal surgeons. Those who considered aspirin as an effective RRM or who felt confident in their knowledge of the aspirin literature were more likely (OR = 10 [95 % CI = 1.5-65], p = 0.010, OR = 6 [95 % CI = 2.2-16], p < 0.001, respectively) to discuss it with their patients than other professionals in the study. Similarly health professionals who felt confident in their knowledge of literature of aspirin/confident in discussing with the patients were more likely (OR = 6 [95 % CI = 2.2-16], p < 0.001) to discuss with their patients. Health professionals who saw more than ten patients with Lynch Syndrome per year were more likely to be confident in their knowledge of the aspirin literature and discussing it with patients (OR = 4.1 [95 % CI = 1.6-10.2], p = 0.003). Explicit recommendations to take aspirin, was reported by 65/83 (78 %) of health professionals. Eighty-seven percent of health professionals reported a need for patient educational materials about aspirin. Continuing training is needed to increase clinicians' confidence in their knowledge of the literature on the use of aspirin as a RRM. Patient education materials may be helpful in improving consistency in patient care and facilitate communication between clinicians and people living with Lynch Syndrome.

Timing of Aspirin and Other Nonsteroidal Anti-Inflammatory Drug Use Among Patients With Colorectal Cancer in Relation to Tumor Markers and Survival

Purpose Regular use of aspirin is associated with improved survival for patients with colorectal cancer (CRC). However, the timing of and the subtype of CRC that would benefit the most from using aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) in relation to survival is unclear. Patients and Methods In all, 2,419 patients age 18 to 74 years with incident invasive CRC who were diagnosed from 1997 to 2008 were identified from population-based cancer registries in the United States, Canada, and Australia. Detailed epidemiologic questionnaires were administered at study enrollment and at 5-year follow-up. Survival outcomes were completed through linkage to national death registries. BRAF- and KRAS-mutation status, microsatellite instability, and CpG island methylator phenotype were also evaluated. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% CIs for overall survival (OS) and CRC-specific survival. Results After a median of 10.8 years of follow-up since diagnosis, 381 deaths (100 as a result of CRC) were observed. Compared with nonusers, postdiagnostic aspirin-only users had more favorable OS (HR, 0.75; 95% CI, 0.59 to 0.95) and CRC-specific survival (HR, 0.44; 95% CI, 0.25 to 0.71), especially among those who initiated aspirin use (OS: HR, 0.64; 95% CI, 0.47 to 0.86; CRC-specific survival: HR, 0.40; 95% CI, 0.20 to 0.80). The association between any NSAID use after diagnosis and OS differed significantly by KRAS-mutation status ( Pinteraction = .01). Use of any NSAID after diagnosis was associated with improved OS only among participants with KRAS wild-type tumors (HR, 0.60; 95% CI, 0.46 to 0.80) but not among those with KRAS-mutant tumors (HR, 1.24; 95% CI, 0.78 to 1.96). Conclusion Among long-term CRC survivors, regular use of NSAIDs after CRC diagnosis was significantly associated with improved survival in individuals with KRAS wild-type tumors.

Drug repurposing in cancer

Cancer is a major health issue worldwide, and the global burden of cancer is expected to increase in the coming years. Whereas the limited success with current therapies has driven huge investments into drug development, the average number of FDA approvals per year has declined since the 1990s. This unmet need for more effective anti-cancer drugs has sparked a growing interest for drug repurposing, i.e. using drugs already approved for other indications to treat cancer. As such, data both from pre-clinical experiments, clinical trials and observational studies have demonstrated anti-tumor efficacy for compounds within a wide range of drug classes other than cancer. Whereas some of them induce cancer cell death or suppress various aspects of cancer cell behavior in established tumors, others may prevent cancer development. Here, we provide an overview of promising candidates for drug repurposing in cancer, as well as studies describing the biological mechanisms underlying their anti-neoplastic effects.

Aspirin-Induced Chemoprevention and Response Kinetics Are Enhanced by PIK3CA Mutations in Colorectal Cancer Cells

This study was designed to determine how aspirin influences the growth kinetics and characteristics of cultured colorectal cancer cells that harbor a variety of different mutational backgrounds, including PIK3CA- and KRAS-activating mutations, and the presence or absence of microsatellite instability. Colorectal cancer cell lines (HCT116, HCT116 + Chr3/5, RKO, SW480, HCT15, CACO2, HT29, and SW48) were treated with pharmacologically relevant doses of aspirin (0.5-10 mmol/L) and evaluated for proliferation and cell-cycle distribution. These parameters were fitted to a mathematical model to quantify the effects and understand the mechanism(s) by which aspirin modifies growth in colorectal cancer cells. We also evaluated the effects of aspirin on key G₀-G₁ cell-cycle genes that are regulated by the PI3K-Akt pathway. Aspirin decelerated growth rates and disrupted cell-cycle dynamics more profoundly in faster growing colorectal cancer cell lines, which tended to be PIK3CA mutants. Additionally, microarray analysis of 151 colorectal cancer cell lines identified important cell-cycle regulatory genes that are downstream targets of PIK3 and were also dysregulated by aspirin treatment (PCNA and RB1). Our study demonstrated what clinical trials have only speculated, that PIK3CA-mutant colorectal cancers are more sensitive to aspirin. Aspirin inhibited cell growth in all colorectal cancer cell lines regardless of mutational background, but the effects were exacerbated in cells with PIK3CA mutations. Mathematical modeling combined with bench science revealed that cells with PIK3CA-mutations experience significant G₀-G₁ arrest and explains why patients with PIK3CA mutant colorectal cancers may benefit from aspirin use after diagnosis. Cancer Prev Res; 10(3); 208-18. ©2017 AACR.

Acetylsalicylic Acid Exhibits Antitumor Effects in Esophageal Adenocarcinoma Cells In Vitro and In Vivo

BACKGROUND AND AIM

Recent observational studies have shown therapeutic benefits of acetylsalicylic acid (ASA) in several types of cancer. We examined whether ASA exerts antitumor activity in esophageal adenocarcinoma (EAC).

METHODS

Human EAC cells (OE33) were treated with ASA (0-5 mM) to evaluate proliferation, apoptosis, and migration. In vivo model: OE33-derived tumors were subcutaneously implanted into athymic mice which were allocated to ASA (5 or 50 mg/kg/day)/vehicle (5-6 animals/group). Tumor growth was assessed every 2-3 days, and after 40 days, mice were euthanized. Plasma drug levels were determined by high-performance liquid chromatography. Histological and immunohistochemical (Ki67, activated caspase-3) analysis of tumors were performed. The effect of ASA on tumor prostaglandin E2 (PGE2) levels was also evaluated.

RESULTS

In vitro cell proliferation and migration were significantly inhibited while apoptosis increased (p < 0.05) by ASA. Although ASA did not induce tumor remission, tumor progression was significantly lower in ASA-treated mice when compared to non-treated animals (478 % in mice treated with 5 mg/kg/day ASA vs. 2696 % control; 748 % in mice treated with 50 mg/kg/day ASA vs. 2670 % control). Maximum tumor inhibition was 92 and 85 %, respectively. This effect was associated with a significant decrease of proliferation index in tumors. ASA 5 mg/kg/day did not modify tumor PGE2 levels. Whereas tumor PGE2 content in mice treated with ASA 50 mg/kg was lower than in control mice, the difference was not significant.

CONCLUSION

Although these results need to be confirmed in other EAC cells, our data suggest a role for ASA in the treatment of this tumor.

Aspirin As Secondary Prevention in Patients With Colorectal Cancer: An Unselected Population-Based Study

Purpose

Regular use of aspirin (acetylsalicylic acid) is associated with reduced incidence and mortality of colorectal cancer (CRC). However, aspirin as primary prevention is debated because of the risk of hemorrhagic adverse effects. Aspirin as secondary prevention may be more justified from a risk-benefit perspective. We have examined the association between aspirin use after the diagnosis of CRC with CRC-specific survival (CSS) and overall survival (OS).

Materials and Methods

An observational, population-based, retrospective cohort study was conducted by linking patients diagnosed with CRC from 2004 through 2011 (Cancer Registry of Norway) with data on their aspirin use (The Norwegian Prescription Database). These registries cover more than 99% of the Norwegian population and include all patients in an unselected and consecutive manner. Exposure to aspirin was defined as receipt of aspirin prescriptions for more than 6 months after the diagnosis of CRC. Multivariable Cox-proportional hazard analyses were used to model survival. The main outcome measures of the study were CSS and OS.

Results

A total of 23,162 patients diagnosed with CRC were included, 6,102 of whom were exposed to aspirin after the diagnosis of CRC (26.3%). The median follow-up time was 3.0 years. A total of 2,071 deaths (32.9%, all causes) occurred among aspirin-exposed patients, of which 1,158 (19.0%) were CRC specific. Among unexposed patients (n = 17,060), there were 7,218 deaths (42.3%), of which 5,375 (31.5%) were CRC specific. In multivariable analysis, aspirin exposure after the diagnosis of CRC was independently associated with improved CSS (hazard ratio [HR], 0.85; 95% CI, 0.79 to 0.92) and OS (HR, 0.95; 95% CI, 0.90 to 1.01).

Conclusion

Aspirin use after the diagnosis of CRC is independently associated with improved CSS and OS.

Risk of prostate cancer in low-dose aspirin users: A retrospective cohort study

A growing body of evidence indicates that use of low-dose aspirin (LDA) reduces the risk of certain adenocarcinomas. While there are several and consistent findings on the protective effect of LDA on colorectal and other cancers, few and conflicting evidence is available on prostate cancer (PCa). The aim of this study was to assess whether LDA reduces the incidence rate of PCa. We conducted a nationwide, population-based, retrospective cohort study by using Health Search IMS Health Longitudinal Patient Database (HSD). Patients with ischemic cardio- or cerebrovascular disease (index date) were identified. Time-dependent multivariable Cox proportional hazard models were adopted to estimate Hazard Ratios (HRs) and related 95% confidence intervals (95% CI) of PCa associated with use of LDA. The exposure was lagged by one year to consider the latency of drug effect on the outcome onset. Within a cohort 13,453 patients, the overall incidence rate of PCa was 2.5 per 1,000 person-years. Use of LDA was associated with a decreased incidence rate of PCa (HR = 0.64; 95% CI: 0.48-0.86), which was primarily driven by a frequency of LDA use equal to or higher than twice per week (HR = 0.60; 95% CI: 0.43-0.83). Such an association was more pronounced (HR = 0.43; 95% CI: 0.21-0.91) when LDA was used for five or more years. Our findings indicate that LDA use might be associated with a reduction of risk of PCa in patients with cardio- or cerebrovascular diseases.

Platelets in cancer. From basic research to therapeutic implications

Platelets are well-known for their major role in primary hemostasis and thrombosis. Cancer patients frequently manifest thrombotic events and present abnormalities in blood coagulation which appear to be linked to altered platelet function and turnover. Moreover, numerous studies indicate an intimate cross-talk between platelets and tumor growth, angiogenesis and metastatic dissemination. Finally, several experimental data and clinical trials suggest possible benefits of anti-platelet drugs on some cancers. Here, we will review the current state of basic biological research regarding the role of platelets in cancer progression. We also critically review the possible clinical applicability of some anti-platelet therapies to limit tumor growth and prevent metastatic dissemination.

Dissecting the Dual Role of AMPK in Cancer: From Experimental to Human Studies

The precise role of 5'AMP-activated kinase (AMPK) in cancer and its potential as a therapeutic target is controversial. Although it is well established that activation of this energy sensor inhibits the main anabolic processes that sustain cancer cell proliferation and growth, AMPK activation can confer on cancer cells the plasticity to survive under metabolic stress such as hypoxia and glucose deprivation, which are commonly observed in fast growing tumors. Thus, AMPK is referred to as both a "conditional" tumor suppressor and "contextual" oncogene. To add a further layer of complexity, AMPK activation in human cancer tissues and its correlation with tumor aggressiveness and progression appears to vary in different contexts. The current review discusses the different faces of this metabolic regulator, the therapeutic implications of its modulation, and provides an overview of the most relevant data available on AMPK activation and AMPK-activating drugs in human studies.

Mechanistic explanation for platelet contribution to cancer metastasis

Cancer-associated mortality is frequently caused by metastasis, however, our understanding of this process remains incomplete and therapeutic options are limited. Metastasis is a dynamic multi-step process involving intravasation of tumor cells into the host's blood and lymphatic vessels, their dissemination within the circulation, and finally arrest and extravasation in a distant organ where they establish secondary tumors. It is generally conceived that platelets contribute to all steps of hematogenous tumor dissemination. In this review, we provide an overview of the current knowledge of the platelet receptors involved in tumor cell-induced platelet aggregation, an essential immune surveillance escape mechanism of circulating tumor cells. We discuss how platelets prevent immunological attack, contribute to tumor cell extravasation and thereby facilitate colonization of distant organs.

Aspirin and COX-2 inhibitor use in patients with stage III colon cancer

We conducted a prospective, observational study of aspirin and COX-2 inhibitor use and survival in stage III colon cancer patients enrolled in an adjuvant chemotherapy trial. Among 799 eligible patients, aspirin use was associated with improved recurrence-free survival (RFS) (multivariable hazard ratio [HR] = 0.51, 95% confidence interval [CI] = 0.28 to 0.95), disease-free survival (DFS) (HR = 0.68, 95% CI = 0.42 to 1.11), and overall survival (OS) (HR = 0.63, 95% CI = 0.35 to 1.12). Adjusted HRs for DFS and OS censored at five years (in an attempt to minimize misclassification from noncancer death) were 0.61 (95% CI = 0.36 to 1.04) and 0.48 (95% CI = 0.23 to 0.99). Among 843 eligible patients, those who used COX-2 inhibitors had multivariable HRs for RFS, DFS, and OS of 0.53 (95% CI = 0.27 to 1.04), 0.60 (95% CI = 0.33 to 1.08), and 0.50 (95% CI = 0.23 to 1.07), and HRs of 0.47 (95% CI = 0.24 to 0.91) and 0.26 (95% CI = 0.08 to 0.81) for DFS and OS censored at five years. Aspirin and COX-2 inhibitor use may be associated with improved outcomes in stage III colon cancer patients.

Prevention and treatment of cancer with aspirin: where do we stand?

Aspirin is arguably the synthesized drug that has been used most commonly in human history. Aspirin was originally developed and marketed for the treatment of inflammatory disorders at the end of the 19th century, but its mechanism of action remained unknown until the second half of the 20th century. Since the latter part of the 20th century aspirin also has been used for the primary and secondary prevention of cardiovascular diseases given its anti-thrombotic properties. An association between intake of aspirin and decreased cancer risk was identified in the past decades. Whether aspirin can be used as an anticancer agent in patients with a diagnosis of cancer was unknown until recently. Recent studies suggest that aspirin might provide therapeutic benefit in the adjuvant treatment of certain forms of cancer. This review provides a critical update on this topic, which has potential implications for oncologists and their patients.

Low-dose aspirin use after diagnosis of colorectal cancer does not increase survival: a case-control analysis of a population-based cohort

BACKGROUND & AIMS

Individuals who began taking low-dose aspirin before they were diagnosed with colorectal cancer were reported to have longer survival times than patients who did not take this drug. We investigated survival times of patients who begin taking low-dose aspirin after a diagnosis of colorectal cancer in a large population-based cohort study.

METHODS

We performed a nested case-control analysis using a cohort of 4794 patients diagnosed with colorectal cancer from 1998 through 2007, identified from the UK Clinical Practice Research Datalink and confirmed by cancer registries. There were 1559 colorectal cancer-specific deaths, recorded by the Office of National Statistics; these were each matched with up to 5 risk-set controls. Conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI), based on practitioner-recorded aspirin usage.

RESULTS

Overall, low-dose aspirin use after a diagnosis of colorectal cancer was not associated with colorectal cancer-specific mortality (adjusted OR = 1.06; 95% CI: 0.92-1.24) or all-cause mortality (adjusted OR = 1.06; 95% CI: 0.94-1.19). A dose-response association was not apparent; for example, low-dose aspirin use for more than 1 year after diagnosis was not associated with colorectal cancer-specific mortality (adjusted OR = 0.98; 95% CI: 0.82-1.19). There was also no association between low-dose aspirin usage and colon cancer-specific mortality (adjusted OR = 1.02; 95% CI: 0.83-1.25) or rectal cancer-specific mortality (adjusted OR = 1.10; 95% CI: 0.88-1.38).

CONCLUSIONS

In a large population-based cohort, low-dose aspirin usage after diagnosis of colorectal cancer did not increase survival time.

Biomarkers in precision therapy in colorectal cancer

Colorectal cancer (CRC) is the most commonly diagnosed cancer in Europe. Because CRC is also a major cause of cancer-related deaths worldwide, a lot of research has been focused on the discovery and development of biomarkers to improve the diagnostic process and to predict treatment outcomes. Up till now only a few biomarkers are recommended by expert panels. Current TNM criteria, however, cause substantial under- and overtreatment of CRC patients. Consequently, there is a growing need for new and efficient biomarkers to ensure optimal treatment allocation. An ideal biomarker should be easily translated into clinical practice, to identify patients who can be spared from treatment or benefit from therapy, ultimately resulting in precision medicine in the future. In this review we aim to provide an overview of a number of frequently studied biomarkers in CRC and, at the same time, we will emphasize the challenges and controversies that withhold the clinical introduction of these biomarkers. We will discuss both prognostic and predictive markers of chemotherapy, aspirin therapy as well as overall therapy toxicity. Currently, only mutant KRAS, mutant BRAF, MSI and the Oncotype DX® Colon Cancer Assay are used in clinical practice. Other biomarker studies showed insufficient evidence to be introduced into clinical practice. Divergent patient selection criteria, absence of validation studies and a large number of single biomarker studies are possibly responsible. We therefore recommend that future studies focus on combining key markers, rather than analysing single markers, standardizing study protocols, and validate the results in independent study cohorts, followed by prospective clinical trials.