Alternate-day, low-dose aspirin and cancer risk: long-term observational follow-up of a randomized trial

Aspirin vs Placebo as Adjuvant Therapy for Breast Cancer: The Alliance A011502 Randomized Trial

Importance

Observational studies of survivors of breast cancer and prospective trials of aspirin for cardiovascular disease suggest improved breast cancer survival among aspirin users, but prospective studies of aspirin to prevent breast cancer recurrence are lacking.

Objective

To determine whether aspirin decreases the risk of invasive cancer events among survivors of breast cancer.

Design, Setting, and Participants

A011502, a phase 3, randomized, placebo-controlled, double-blind trial conducted in the United States and Canada with 3020 participants who had high-risk nonmetastatic breast cancer, enrolled participants from 534 sites from January 6, 2017, through December 4, 2020, with follow-up to March 4, 2023.

Interventions

Participants were randomized (stratified for hormone receptor status [positive vs negative], body mass index [≤30 vs >30], stage II vs III, and time since diagnosis [<18 vs ≥18 months]) to receive 300 mg of aspirin (n = 1510) or placebo once daily (n = 1510) for 5 years.

Main Outcomes and Measures

The primary outcome was invasive disease-free survival. Overall survival was a key secondary outcome.

Results

A total of 3020 participants were randomized when the data and safety monitoring committee recommended suspending the study at the first interim analysis because the hazard ratio had crossed the prespecified futility bound. By median follow-up of 33.8 months (range, 0.1-72.6 months), 253 invasive disease-free survival events were observed (141 in the aspirin group and 112 in the placebo group), yielding a hazard ratio of 1.27 (95% CI, 0.99-1.63; P = .06). All invasive disease-free survival events, including death, invasive progression (both distant and locoregional), and new primary events, were numerically higher in the aspirin group, although the differences were not statistically significant. There was no difference in overall survival (hazard ratio, 1.19; 95% CI, 0.82-1.72). Rates of grades 3 and 4 adverse events were similar in both groups.

Conclusion and Relevance

Among participants with high-risk nonmetastatic breast cancer, daily aspirin therapy did not improve risk of breast cancer recurrence or survival in early follow-up. Despite its promise and wide availability, aspirin should not be recommended as an adjuvant breast cancer treatment.

Trial Registration

ClinicalTrials.gov Identifier: NCT02927249.

Thromboxane biosynthesis and future events in diabetes: the ASCEND trial

BACKGROUND AND AIMS

Thromboxane (TX) A2, released by activated platelets, plays an important role in atherothrombosis. Urinary 11-dehydro-TXB2 (U-TXM), a stable metabolite reflecting the whole-body TXA2 biosynthesis, is reduced by ∼70% by daily low-dose aspirin. The U-TXM represents a non-invasive biomarker of in vivo platelet activation and is enhanced in patients with diabetes. This study assessed whether U-TXM is associated with the risk of future serious vascular events or revascularizations (SVE-R), major bleeding, or cancer in patients with diabetes.

METHODS

The U-TXM was measured pre-randomization to aspirin or placebo in 5948 people with type 1 or 2 diabetes and no cardiovascular disease, in the ASCEND trial. Associations between log U-TXM and SVE-R (n = 618), major bleed (n = 206), and cancer (n = 700) during 6.6 years of follow-up were investigated by Cox regression; comparisons of these associations with the effects of randomization to aspirin were made.

RESULTS

Higher U-TXM was associated with older age, female sex, current smoking, type 2 diabetes, higher body size, urinary albumin/creatinine ratio of ≥3 mg/mmol, and higher estimated glomerular filtration rate. After adjustment for these, U-TXM was marginally statistically significantly associated with SVE-R and major bleed but not cancer [hazard ratios per 1 SD higher log U-TXM (95% confidence interval): 1.09 (1.00-1.18), 1.16 (1.01-1.34), and 1.06 (0.98-1.14)]. The hazard ratio was similar to that implied by the clinical effects of randomization to aspirin for SVE-R but not for major bleed.

CONCLUSIONS

The U-TXM was log-linearly independently associated with SVE-R in diabetes. This is consistent with the involvement of platelet TXA2 in diabetic atherothrombosis.

Long-term aspirin use and cancer risk: a 20-year cohort study

BACKGROUND

Long-term use of aspirin has been shown to reduce colorectal cancer risk, but the association remains inconclusive for individual noncolorectal cancers. We examined the association between long-term aspirin use and cancer risk in Denmark.

METHODS

Using nationwide registries, we followed individuals aged 40-70 years at baseline (January 1, 1997) for cancer diagnoses through 2018. We assessed low-dose (75-150 mg) aspirin use according to continuity, duration, and cumulative amount. In addition, we explored associations with consistent high-dose (500 mg) aspirin use. Using Cox regression, we estimated multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) with aspirin use for overall and site-specific cancer.

RESULTS

Among 1 909 531 individuals, 422 778 were diagnosed with cancer during mean follow-up of 18.2 years. Low-dose aspirin use did not reduce the hazard ratio for cancer overall irrespective of continuity and duration of use (continuous use: HR = 1.04, 95% CI = 1.03 to 1.06). However, long-term (≥5 or ≥10 years) use was associated with at least 10% reductions in hazard ratios for several cancer sites: colon, rectum, esophagus, stomach, liver, pancreas, small intestine, head and neck, brain tumors, meningioma, melanoma, thyroid, non-Hodgkin lymphoma, and leukemia. Substantially elevated hazard ratios were found for lung and bladder cancer. In secondary analyses, consistent high-dose aspirin use was associated with reduced hazard ratios for cancer overall (HR = 0.89, 95% CI = 0.85 to 0.93) and for several cancer sites.

CONCLUSION

Long-term low-dose aspirin use was associated with slight to moderately reduced risks for several cancers but not for cancer overall owing to increased risk for some common cancers. Similar or slightly stronger inverse associations were observed for consistent use of high-dose aspirin.

Aspirin chemoprevention in colorectal cancer: network meta-analysis of low, moderate, and high doses

BACKGROUND

Colorectal cancer is the third most common cancer, with nearly 2 million cases worldwide and just under 1 million deaths in 2020. Several trials have demonstrated that aspirin has the potential to reduce the incidence and/or recurrence of colorectal cancer; however, the optimal aspirin dose is unclear.

METHODS

Relevant studies were identified by searching MEDLINE, Embase and the Cochrane Library from database inception to 2 February 2022. Data from RCTs in which the incidence of colorectal cancer in patients without active colorectal cancer assigned to aspirin versus control were included. Two investigators independently identified studies and abstracted data. Study quality was assessed using Cochrane Collaboration risk-of-bias 2 tool. The study was performed according to PRISMA guidelines. Aspirin dose was stratified into low (50-163 mg/day), mid (164-325 mg/day), and high (500-1200 mg/day).

RESULTS

Thirteen articles representing 11 RCTs (92 550 participants) were included, with studies assessing aspirin as primary prophylaxis in general or high-risk populations, and as secondary prophylaxis for metachronous colorectal cancer. There was a statistically significant reduction in colorectal cancer incidence in the high-dose aspirin group compared with the group that received no aspirin or placebo (OR 0.69, 95 per cent credible interval 0.50 to 0.96; surface under the cumulative ranking 0.82). There was no statistically significant difference between mid- and low-dose aspirin versus no aspirin/placebo.

CONCLUSION

In this network meta-analysis of RCTs, high-dose aspirin was associated with a reduction in colorectal cancer incidence. However, this was based on a limited number of trials. This study did not show a statistically significant risk reduction in colorectal cancer incidence with mid- or low-dose aspirin.

Human cytomegalovirus infection enhances 5‑lipoxygenase and cycloxygenase‑2 expression in colorectal cancer

Colorectal cancer (CRC) is one of the most common and fatal types of cancer. Inflammation promotes CRC development, however, the underlying etiological factors are unknown. Human cytomegalovirus (HCMV), a virus that induces inflammation and other cancer hallmarks, has been detected in several types of malignancy, including CRC. The present study investigated whether HCMV infection was associated with expression of the pro‑inflammatory enzymes 5‑lipoxygenase (5‑LO) and cyclooxygenase‑2 (COX‑2) and other molecular, genetic and clinicopathological CRC features. The present study assessed 146 individual paraffin‑embedded CRC tissue microarray (TMA) cores already characterized for TP53 and KRAS mutations, microsatellite instability (MSI) status, Ki‑67 index and EGFR by immunohistochemistry (IHC). The cores were further analyzed by IHC for the expression of two HCMV proteins (Immediate Early, IE and pp65) and the inflammatory markers 5‑LO and COX‑2. The CRC cell lines Caco‑2 and LS‑174T were infected with HCMV strain VR1814, treated with antiviral drug ganciclovir (GCV) and/or anti‑inflammatory drug celecoxib (CCX) and analyzed by reverse transcription‑quantitative PCR and immunofluorescence for 5‑LO, COX‑2, IE and pp65 transcripts and proteins. HCMV IE and pp65 proteins were detected in ~90% of the CRC cases tested; this was correlated with COX‑2, 5‑LO and KI‑67 expression, but not with EGFR immunostaining, TP53 and KRAS mutations or MSI status. In vitro, HCMV infection upregulated 5‑LO and COX‑2 transcript and proteins in both Caco‑2 and LS‑174T cells and enhanced cell proliferation as determined by MTT assay. Treatment with GCV and CCX significantly decreased the transcript levels of COX‑2, 5‑LO, HCMV IE and pp65 in infected cells. HCMV was widely expressed in CRC and may promote inflammation and serve as a potential new target for CRC therapy.

Colorectal polyp outcomes after participation in the seAFOod polyp prevention trial: Evidence of rebound elevated colorectal polyp risk after short-term aspirin use

BACKGROUND

The seAFOod polyp prevention trial was a randomised, placebo-controlled, 2 × 2 factorial trial of aspirin 300 mg and eicosapentaenoic acid (EPA) 2000 mg daily in individuals who had a screening colonoscopy in the English Bowel Cancer Screening Programme (BCSP). Aspirin treatment was associated with a 20% reduction in colorectal polyp number at BCSP surveillance colonoscopy 12 months later. It is unclear what happens to colorectal polyp risk after short-term aspirin use.

AIM

To investigate colorectal polyp risk according to the original trial treatment allocation, up to 6 years after trial participation.

METHODS

All seAFOod trial participants were scheduled for further BCSP surveillance and provided informed consent for the collection of colonoscopy outcomes. We linked BCSP colonoscopy data to trial outcomes data.

RESULTS

In total, 507 individuals underwent one or more colonoscopies after trial participation. Individuals grouped by treatment allocation were well matched for clinical characteristics, follow-up duration and number of surveillance colonoscopies. The polyp detection rate (PDR; the number of individuals who had ≥1 colorectal polyp detected) after randomization to placebo aspirin was 71.1%. The PDR was 80.1% for individuals who had received aspirin (odds ratio [OR] 1.13 [95% confidence interval 1.02, 1.24]; p = 0.02). There was no difference in colorectal polyp outcomes between individuals who had been allocated to EPA compared with its placebo (OR for PDR 1.00 [0.91, 1.10]; p = 0.92).

CONCLUSION

Individuals who received aspirin in the seAFOod trial demonstrated increased colorectal polyp risk during post-trial surveillance. Rebound elevated neoplastic risk after short-term aspirin use has important implications for aspirin cessation driven by age-related bleeding risk. ISRCTN05926847.

Association between use of low-dose aspirin and detection of colorectal polyps and cancer in a screening setting

BACKGROUND

The possible protective effect of aspirin on risk of colorectal cancer (CRC) is still highly debated.

METHODS

We used data from Bowel Cancer Screening in Norway, a trial randomizing individuals from general population, aged 50-74 years, to flexible sigmoidoscopy or faecal immunochemical test (FIT), to study the association between aspirin use and detection of CRC and two CRC precursors: adenomas and advanced serrated lesions (ASL). Prescriptions of low-dose aspirin were obtained from Norwegian prescription database. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among 64,889 screening participants (24,159 sigmoidoscopy, 40,730 FIT), 314 (0.5%) had CRC, 6,208 (9.6%) adenoma and 659 (1.0%) ASL. Overall and short-term use (<3 years) of low-dose aspirin, versus no use, were not associated with any colorectal lesion. Long-term use (≥3 years) was associated with lower detection of CRC (overall OR 0.66, 95%CI 0.46-0.93; sigmoidoscopy: 0.56, 0.33-0.97; FIT: 0.72, 0.45-1.15), adenomas in sigmoidoscopy arm (overall OR 0.95, 95%CI 0.87-1.03; sigmoidoscopy: 0.89, 0.80-0.99; FIT: 1.03, 0.89-1.18), but not ASLs. We did not observe significant differences in the effect of aspirin according to the location of colorectal lesions.

CONCLUSION

Our results suggest that long-term use of aspirin might have a protective effect against adenomas and colorectal cancer, but not ASLs.

Biology of Precancers and Opportunities for Cancer Interception: Lesson from Colorectal Cancer Susceptibility Syndromes

Hereditary gastrointestinal cancer is associated with molecular and neoplastic precursors which have revealed much about sporadic carcinogenesis. Therefore, an appreciation of constitutional and somatic events linked to these syndromes have provided a useful model for the development of risk models and preventative strategies. In this review, we focus of two of the best characterized syndromes, Lynch syndrome (LS) and familial adenomatous polyposis (FAP). Our understanding of the neoplasia-immune interaction in LS has contributed to the development of immune mediated therapies including cancer preventing vaccines and immunotherapy for cancer precursors. Chemoprevention in LS with aspirin and nonsteroidal anti-inflammatory drugs has also translated into clinical cancer, however the efficacy of such agents in FAP remains elusive when cancer is applied as an endpoint in trials rather than the use of 'indirect' endpoints such as polyp burden, and requires further elucidation of biological mechanisms in FAP. Finally, we review controversies in gastrointestinal surveillance for LS and FAP, including limitations and opportunities of upper and lower gastrointestinal endoscopy in the prevention and early detection of cancer.

[Esophageal Cancer]

Esophageal cancer has poor prognosis and high letality. With yearly 600,000 new cases worldwide it ist he sixt most common cancer worldwide and the eight most deadly. Squamous cell carcinoma is more common in Africa and Asia, whereas incidence of adenocarcinoma ist increasing in Norh America and Europe. Riskfactors include alcohol, smoking, obesity, esophageal stenosis or achalasia. Currently there are no recommendations for prevention strategies or cancer screening. Symptoms in early stages are unspecific, so diagnosis is made late. Diagnostics include gastroscopy, CT, PET and endosonography. Therapeutic approaches are depending on disease stage and patients general condition. In early stages endoscopic resection is the treatment of choice. In higher stages theraoy consists of surgical resection and radiochemotherapy. Generalised stade ist treated with palliative systemic therapy and local interventions.

The Application of Lag Times in Cancer Pharmacoepidemiology: A Narrative Review

With the increasing utilization of medications worldwide, coupled with the increasing availability of long-term data, there is a growing opportunity and need for robust studies evaluating drug-cancer associations. One methodology of importance in such studies is the application of lag times. In this review, we discuss the main reasons for using lag times. Namely, we discuss the typically long latency period of cancer concerning both tumor promoter and initiator effects and outline why cancer latency is a key consideration when choosing a lag time. We also discuss how the use of lag times can help reduce protopathic and detection bias. Finally, we present practical advice for implementing lag periods. In general, we recommend that researchers consider the information that generated the hypothesis as well as clinical and biological knowledge to inform lag period selection. In addition, given that latency periods are usually unknown, we also advocate that researchers examine multiple lag periods in sensitivity analyses as well as duration analyses and flexible modeling approaches.

Colorectal Cancer Chemoprevention: A Dream Coming True?

Colorectal cancer (CRC) is one of the deadliest forms of cancer worldwide. CRC development occurs mainly through the adenoma-carcinoma sequence, which can last decades, giving the opportunity for primary prevention and early detection. CRC prevention involves different approaches, ranging from fecal occult blood testing and colonoscopy screening to chemoprevention. In this review, we discuss the main findings gathered in the field of CRC chemoprevention, focusing on different target populations and on various precancerous lesions that can be used as efficacy evaluation endpoints for chemoprevention. The ideal chemopreventive agent should be well tolerated and easy to administer, with low side effects. Moreover, it should be readily available at a low cost. These properties are crucial because these compounds are meant to be used for a long time in populations with different CRC risk profiles. Several agents have been investigated so far, some of which are currently used in clinical practice. However, further investigation is needed to devise a comprehensive and effective chemoprevention strategy for CRC.

Antiplatelet drugs and breast cancer risk in a large nationwide Danish case-control study

Low-dose aspirin has been hypothesized to prevent cancer risk by inhibiting platelet aggregation. However, the anti-cancer effect of low-dose aspirin has recently been questioned and its effect on breast cancer development remains unclear. The impact of other antiplatelet drugs on breast cancer risk has rarely been evaluated. Thus, this study aimed to investigate the associations between breast cancer risk and antiplatelet drug use in a nationwide nested case-control study. From the Danish healthcare registries, we identified as cases all women with invasive breast cancer diagnosis between 2001 and 2018 (n = 68 852). The date of diagnosis corresponded to the index date. We matched cases to 10 population controls on age and calendar time, using risk set sampling. Controls were assigned the same index date as their matched case. We used the prescription registry to identify exposure to low-dose aspirin, clopidogrel and dipyridamole. We defined ever use of antiplatelet drugs as at least two prescriptions filled up to 1 year before the index date. We applied conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals for breast cancer associated with the use of antiplatelet drugs, overall, by breast cancer subtype and by cumulative dose. Twelve percent of women had ever been exposed to low-dose aspirin, 2% to clopidogrel and 2% to dipyridamole. In multivariable models, breast cancer risk was not associated with ever use of low-dose aspirin (OR = 1.00 [0.97-1.03]), clopidogrel (OR = 0.93 [0.87-1.00]), and dipyridamole (OR = 1.02 [0.94-1.10]), compared with never use, and there was no evidence of a dose-response relation. However, we found an inverse association between dipyridamole use and breast cancer risk among women aged <55 years old, with suggestion of a dose-response relationship (OR per 1000 Defined Daily Doses = 0.72 [0.54-0.95]). Associations did not differ by breast cancer histological type, estrogen receptor status or clinical stage at diagnosis. Overall, the findings from this study do not support the use of antiplatelet drugs for breast cancer prevention.

Low-dose aspirin does not lower the risk of colorectal cancer in patients with type 2 diabetes taking metformin

BACKGROUND

Low-dose aspirin and metformin have been individually associated with a reduced risk of cancer. Whether their concurrent use in adults with type 2 diabetes mellitus (T2DM) is associated with a reduced risk of colorectal cancer (CRC) is unclear.

OBJECTIVE

Among individuals with T2DM taking metformin, we sought to evaluate the association between low-dose aspirin versus no aspirin and the risk of CRC.

METHODS

A multiple-database new-user cohort study of patients with T2DM taking metformin was conducted between 2007 and 2010 (Clinical Data Analysis and Reporting System [CDARS], Hong Kong) and 2007-2016 (The Health Improvement Network [THIN], UK). The primary outcome was incident CRC. Patients were followed from index date of prescription until the earliest occurrence of an outcome of interest, an incident diagnosis of any cancer, death, or until 31 December 2019. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CI). Estimates were pooled using an inverse variance random effects model, and heterogeneity was assessed using I² .

RESULTS

After one-to-one propensity-score matching, 57,534 patients were included (CDARS = 16,276; THIN = 41,258). The median (IQR) follow-up was 9.3 (6.5-10.7) years in CDARS and 3.2 (1.1-5.8) years in THIN. The concurrent use of low-dose aspirin and metformin was not associated with a lower risk of CRC compared to metformin only (HR = 0.89, 95% CI 0.75-1.05, I²  = 0%).

CONCLUSION

Low-dose aspirin was not associated with a lower risk of CRC in patients with T2DM taking metformin. Our study does not support the routine use of low-dose aspirin in this population.

Acetylsalicylic Acid Effect in Colorectal Cancer Taking into Account the Role of Tobacco, Alcohol and Excess Weight

Excess weight, smoking and risky drinking are preventable risk factors for colorectal cancer (CRC). However, several studies have reported a protective association between aspirin and the risk of CRC. This article looks deeper into the relationships between risk factors and aspirin use with the risk of developing CRC. We performed a retrospective cohort study of CRC risk factors and aspirin use in persons aged >50 years in Lleida province. The participants were inhabitants with some medication prescribed between 2007 and 2016 that were linked to the Population-Based Cancer Registry to detect CRC diagnosed between 2012 and 2016. Risk factors and aspirin use were studied using the adjusted HR (aHR) with 95% confidence intervals (CI) using a Cox proportional hazard model. We included 154,715 inhabitants of Lleida (Spain) aged >50 years. Of patients with CRC, 62% were male (HR = 1.8; 95% CI: 1.6-2.2), 39.5% were overweight (HR = 2.8; 95% CI: 2.3-3.4) and 47.3% were obese (HR = 3.0; 95% CI: 2.6-3.6). Cox regression showed an association between aspirin and CRC (aHR = 0.7; 95% CI: 0.6-0.8), confirming a protective effect against CRC and an association between the risk of CRC and excess weight (aHR = 1.4; 95% CI: 1.2-1.7), smoking (aHR = 1.4; 95% CI: 1.3-1.7) and risky drinking (aHR = 1.6; 95% CI: 1.2-2.0). Our results show that aspirin use decreased the risk of CRC and corroborate the relationship between overweight, smoking and risky drinking and the risk of CRC.

Use of Nonsteroidal Anti-Inflammatory Drugs and Risk of Breast Cancer: Evidence from a General Female Population and a Mammographic Screening Cohort in Sweden

A link has been proposed between the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and the risk of breast cancer. There is, however, insufficient data regarding the subtype and stage of breast cancer, and few studies have assessed the interaction between the use of NSAIDs and breast density or previous breast disorders. There is also a lack of data from population-based studies. We first conducted a nested case-control study within the general female population of Sweden, including 56,480 women with newly diagnosed breast cancer during 2006-2015 and five breast cancer-free women per case as controls, to assess the association of NSAID use with the risk of incident breast cancer, focusing on subtype and stage of breast cancer as well as the interaction between NSAID use and previous breast disorders. We then used the Karolinska Mammography Project for Risk Prediction of Breast Cancer (Karma) cohort to assess the interaction between NSAID use and breast density in relation to the risk of breast cancer. Conditional logistic regression was used to estimate the hazard ratio (HR) and a 95% confidence interval (CI) was used for breast cancer in relation to the use of aspirin and non-aspirin NSAIDs. In the nested case-control study of the general population, exclusive use of aspirin was not associated with the risk of breast cancer, whereas exclusive use of non-aspirin NSAIDs was associated with a modestly higher risk of stage 0-2 breast cancer (HR: 1.05; 95% CI: 1.02-1.08) but a lower risk of stage 3-4 breast cancer (HR 0.80; 95% CI: 0.73-0.88). There was also a statistically significant interaction between the exclusive use of NSAIDs and previous breast disorders (p for interaction: <0.001). In the analysis of Karma participants, the exclusive use of non-aspirin NSAIDs was associated with a lower risk of breast cancer among women with a breast dense area of >40 cm² (HR: 0.72; 95% CI: 0.59-0.89). However, the possibility of finding this by chance cannot be ruled out. Overall, we did not find strong evidence to support an association between the use of NSAIDs and the risk of breast cancer.

Fifty years with aspirin and platelets

In 2021, we reached the 50th anniversary of the publication of Sir John Vane's seminal paper in Nature New Biology describing the experiments supporting his mechanistic hypothesis that inhibition of prostaglandin synthesis might explain the main pharmacological effects of aspirin and aspirin-like drugs, that is, reduction in pain, fever and inflammation. Bengt Samuelsson's subsequent discoveries elucidating the cyclooxygenase pathway of platelet arachidonic acid metabolism motivated my research interest towards measuring platelet thromboxane A₂ biosynthesis as a tool to investigate the clinical pharmacology of cyclooxygenase inhibition by aspirin in health and disease. What followed was a long, winding road of clinical research leading to the characterization of low-dose aspirin as a life-saving antiplatelet drug that still represents the cornerstone of antithrombotic therapy. Having witnessed and participated in these 50 years of aspirin research, I thought of providing a personal testimony of how things developed and eventually led to a remarkable success story of independent research.

Colorectal cancer chemoprevention: is aspirin still in the game?

Screening strategies have demonstrated their potential for decreasing the incidence and mortality of cancers, particularly that of colorectal cancer (CRC). Another strategy that has been developed to reduce CRC occurrence is the use of chemoprevention agents. Among them, aspirin is the most promising. Aspirin acts in colorectal tumourigenesis through several mechanisms, either directly in tumor cells or in their microenvironment, such as through its anti-inflammatory activity or its effect on the modulation of platelet function. Many retrospective studies, as well as follow-up of large cohorts from trials with primary cardiovascular end points, have shown that long-term treatment with daily low-dose aspirin decreases the incidence of adenomas and colorectal cancers. Therefore, aspirin is currently recommended by the United States Preventive Services Task Force (USPSTF) for primary prevention of CRC in all patients aged 50 to 59 with a 10-y risk of cardiovascular events greater than 10%. Furthermore, several studies have also reported that long-term aspirin treatment taking after CRC resection decreases recurrence risk and increases overall survival, especially in patients with PIK3CA-mutated tumors. This review summarizes current knowledge on the pathophysiological mechanisms of aspirin chemoprevention, discusses the primary clinical results on CRC prevention and highlights the potential biomarkers identified to predict aspirin efficacy.

Aspirin for Colorectal Cancer Prevention: Age Matters

Further data from the Aspirin in Reducing Events in the Elderly (ASPREE) trial heightens the concern regarding aspirin use for colorectal cancer prevention in elderly subjects. A 95-variant colorectal cancer polygenic risk score (PRS) failed to identify a subset of elderly individuals who could have benefited from aspirin preventive activity. Further research to define predictive biomarkers of aspirin preventive activity is needed. Meanwhile, the use of aspirin for colorectal cancer prevention in the elderly becomes more questionable. See Cancer Prev Res 15(7):447-53.

Cell-Cell Interactions Drive Metastasis of Circulating Tumor Microemboli

Circulating tumor cells are the cellular mediators of distant metastasis in solid malignancies. Their metastatic potential can be augmented by clustering with other tumor cells or nonmalignant cells, forming circulating tumor microemboli (CTM). Cell-cell interactions are key regulators within CTM that convey enhanced metastatic properties, including improved cell survival, immune evasion, and effective extravasation into distant organs. However, the cellular and molecular mechanism of CTM formation, as well as the biology of interactions between tumor cells and immune cells, platelets, and stromal cells in the circulation, remains to be determined. Here, we review the current literature on cell-cell interactions in homotypic and heterotypic CTM and provide perspectives on therapeutic strategies to attenuate CTM-mediated metastasis by targeting cell-cell interactions.

Aspirin and the Risk of Colorectal Cancer According to Genetic Susceptibility among Older Individuals

Although aspirin has been considered a promising agent for prevention of colorectal cancer, recent data suggest a lack of benefit among older individuals. Whether some individuals with higher risk of colorectal cancer may benefit from aspirin remains unknown. We used a 95-variant colorectal cancer polygenic risk score (PRS) to explore the association between genetic susceptibility to colorectal cancer and aspirin use in a prospective study of 12,609 individuals of European descent ages ≥70 years, enrolled in the ASPirin in Reducing Events in the Elderly (ASPREE) double-blinded, placebo-controlled randomized trial (randomized controlled trial; RCT). Cox proportional hazards models were used to assess the association of aspirin use on colorectal cancer, as well as the interaction between the PRS and aspirin treatment on colorectal cancer. Over a median of 4.7 years follow-up, 143 participants were diagnosed with incident colorectal cancer. Aspirin assignment was not associated with incidence of colorectal cancer overall [HR = 0.94; 95% confidence interval (CI), 0.68-1.30] or within strata of PRS (P for interaction = 0.97). However, the PRS was associated with an increased risk of colorectal cancer (HR = 1.28 per SD; 95% CI, 1.09-1.51). Individuals in the top quintile of the PRS distribution had an 85% higher risk compared with individuals in the bottom quintile (HR = 1.85; 95% CI, 1.08-3.15). In a prospective RCT of older individuals, a PRS is associated with incident colorectal cancer risk, but aspirin use was not associated with a reduction of incident colorectal cancer, regardless of baseline genetic risk.

PREVENTION RELEVANCE

There is strong evidence to support prophylactic aspirin use for the prevention of colorectal cancer. However recent recommendations suggest the risk of bleeding in older individuals outweighs the benefit. We sought to determine whether some older individuals might still benefit from aspirin based on their genetic susceptibility.

Challenges and Opportunities Associated With Platelets in Pancreatic Cancer

Pancreatic cancer is one of the most common malignant tumors in the digestive system with a poor prognosis. Accordingly, better understanding of the molecular mechanisms and innovative therapies are warranted to improve the prognosis of this patient population. In addition to playing a crucial role in coagulation, platelets reportedly contribute to the growth, invasion and metastasis of various tumors, including pancreatic cancer. This narrative review brings together currently available evidence on the impact of platelets on pancreatic cancer, including the platelet-related molecular mechanisms of cancer promotion, pancreatic cancer fibrosis, immune evasion, drug resistance mechanisms, thrombosis, targeted platelet therapy, combined radiotherapy and chemotherapy treatment, platelet combined with nanotechnology treatment and potential applications of pancreatic cancer organoids. A refined understanding of the role of platelets in pancreatic cancer provides the foothold for identifying new therapeutic targets.

Aspirin Use to Prevent Cardiovascular Disease and Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Low-dose aspirin is used for primary cardiovascular disease prevention and may have benefits for colorectal cancer prevention.

OBJECTIVE

To review the benefits and harms of aspirin in primary cardiovascular disease prevention and colorectal cancer prevention to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, Embase, and the Cochrane Central Register of Controlled Trials through January 2021; literature surveillance through January 21, 2022.

STUDY SELECTION

English-language randomized clinical trials (RCTs) of low-dose aspirin (≤100 mg/d) compared with placebo or no intervention in primary prevention populations.

DATA EXTRACTION AND SYNTHESIS

Single extraction, verified by a second reviewer. Quantitative synthesis using Peto fixed-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Cardiovascular disease events and mortality, all-cause mortality, colorectal cancer incidence and mortality, major bleeding, and hemorrhagic stroke.

RESULTS

Eleven RCTs (N = 134 470) and 1 pilot trial (N = 400) of low-dose aspirin for primary cardiovascular disease prevention were included. Low-dose aspirin was associated with a significant decrease in major cardiovascular disease events (odds ratio [OR], 0.90 [95% CI, 0.85-0.95]; 11 RCTs [n = 134 470]; I2 = 0%; range in absolute effects, -2.5% to 0.1%). Results for individual cardiovascular disease outcomes were significant, with similar magnitude of benefit. Aspirin was not significantly associated with reductions in cardiovascular disease mortality or all-cause mortality. There was limited trial evidence on benefits for colorectal cancer, with the findings highly variable by length of follow-up and statistically significant only when considering long-term observational follow-up beyond randomized trial periods. Low-dose aspirin was associated with significant increases in total major bleeding (OR, 1.44 [95% CI, 1.32-1.57]; 10 RCTs [n = 133 194]; I2 = 4.7%; range in absolute effects, 0.1% to 1.0%) and in site-specific bleeding, with similar magnitude.

CONCLUSIONS AND RELEVANCE

Low-dose aspirin was associated with small absolute risk reductions in major cardiovascular disease events and small absolute increases in major bleeding. Colorectal cancer results were less robust and highly variable.

Aspirin Use to Prevent Cardiovascular Disease: US Preventive Services Task Force Recommendation Statement

IMPORTANCE

Cardiovascular disease (CVD) is the leading cause of mortality in the US, accounting for more than 1 in 4 deaths. Each year, an estimated 605 000 people in the US have a first myocardial infarction and an estimated 610 000 experience a first stroke.

OBJECTIVE

To update its 2016 recommendation, the US Preventive Services Task Force (USPSTF) commissioned a systematic review on the effectiveness of aspirin to reduce the risk of CVD events (myocardial infarction and stroke), cardiovascular mortality, and all-cause mortality in persons without a history of CVD. The systematic review also investigated the effect of aspirin use on colorectal cancer (CRC) incidence and mortality in primary CVD prevention populations, as well as the harms (particularly bleeding) associated with aspirin use. The USPSTF also commissioned a microsimulation modeling study to assess the net balance of benefits and harms from aspirin use for primary prevention of CVD and CRC, stratified by age, sex, and CVD risk level.

POPULATION

Adults 40 years or older without signs or symptoms of CVD or known CVD (including history of myocardial infarction or stroke) who are not at increased risk for bleeding (eg, no history of gastrointestinal ulcers, recent bleeding, other medical conditions, or use of medications that increase bleeding risk).

EVIDENCE ASSESSMENT

The USPSTF concludes with moderate certainty that aspirin use for the primary prevention of CVD events in adults aged 40 to 59 years who have a 10% or greater 10-year CVD risk has a small net benefit. The USPSTF concludes with moderate certainty that initiating aspirin use for the primary prevention of CVD events in adults 60 years or older has no net benefit.

RECOMMENDATION

The decision to initiate low-dose aspirin use for the primary prevention of CVD in adults aged 40 to 59 years who have a 10% or greater 10-year CVD risk should be an individual one. Evidence indicates that the net benefit of aspirin use in this group is small. Persons who are not at increased risk for bleeding and are willing to take low-dose aspirin daily are more likely to benefit. (C recommendation) The USPSTF recommends against initiating low-dose aspirin use for the primary prevention of CVD in adults 60 years or older. (D recommendation).

Terapia endocrina para la prevención primaria del cáncer de seno: Revisión sistemática y metaanálisis actualizado

Introducción. Debido a que el cáncer de seno es una enfermedad asociada a una significativa tasa de morbilidad y mortalidad cuando se diagnostica en el período sintomático, se han hecho enormes esfuerzos orientados hacia la prevención primaria de esta enfermedad. Métodos. Se realizó una búsqueda de todos los experimentos clínicos aleatorizados que evaluaran la eficacia de la terapia endocrina para la reducción del riesgo de desarrollar cáncer de seno. La calidad metodológica de los estudios seleccionados fue valorada utilizando la herramienta de la Colaboración Cochrane para medir el riesgo de sesgo en ensayos aleatorizados. Se evaluó la heterogeneidad de los estudios primarios elegibles utilizando los estadísticos T², I², H². El sesgo de publicación fue evaluado mediante el test de Harbord y mediante la gráfica de funnel plot. La medida de efecto utilizada en este metaanálisis fue el riesgo relativo (RR) con el cálculo de los intervalos de confianza (IC) del 95%. Resultados. Encontramos doce experimentos clínicos aleatorizados que reclutaron a 68.180 mujeres, las cuales fueron asignadas al azar para recibir algún tipo terapia endocrina para reducir el riesgo de desarrollar cáncer de seno o placebo. La terapia endocrina en conjunto redujo el riesgo proporcional de cáncer de seno (invasivo más in situ) en un 42 %, resultado estadísticamente significativo RR 0,58 (IC95% 0,50 – 0,69). Conclusiones. La terapia endocrina es el manejo estándar de prevención en mujeres sanas con riesgo de desarrollar cáncer de seno no hereditario.

Aspirin Colorectal Cancer Prevention in Lynch Syndrome: Recommendations in the Era of Precision Medicine

Cancer prevention in the era of precision medicine has to consider integrated therapeutic approaches. Therapeutic cancer prevention should be offered to selected cohorts with increased cancer risk. Undoubtedly, carriers of hereditary cancer syndromes have a well-defined high cancer risk. Lynch Syndrome is one of the most frequent hereditary syndromes; it is mainly associated with colorectal cancer (CRC). Nonsteroidal anti-inflammatory drugs and, in particular, aspirin use, has been associated with reduced CRC risk in several studies, initially with contradictory results; however, longer follow-up confirmed a reduced CRC incidence and mortality. The CAPP2 study recruited 861 Lynch syndrome participants randomly assigned to 600 mg of aspirin versus placebo. Like sporadic CRCs, a significant CRC risk reduction was seen after an extended follow-up, with a median treatment time that was relatively short (2 years). The ongoing CAPP3 will address whether lower doses are equally effective. Based on pharmacology and clinical data on sporadic CRCs, the preventive effect should also be obtained with low-dose aspirin. The leading international guidelines suggest discussing with Lynch syndrome carriers the possibility of using low-dose aspirin for CRC prevention. We aim systematically promote this intervention with all Lynch syndrome carriers.

Safety and effectiveness of low-dose aspirin for the prevention of gastrointestinal cancer in adults without atherosclerotic cardiovascular disease: a population-based cohort study

OBJECTIVE

To assess the association between low-dose aspirin and the incidence of colorectal cancer (CRC), gastric cancer (GC), oesophageal cancer (EC) and gastrointestinal bleeding (GIB) in adults without established atherosclerotic cardiovascular disease.

DESIGN

Cohort study with propensity score matching of new-users of aspirin to non-users.

SETTING

Clinical Data Analysis and Reporting System database, Hong Kong.

PARTICIPANTS

Adults ≥40 years with a prescription start date of either low-dose aspirin (75-300 mg/daily) or paracetamol (non-aspirin users) between 1 January 2004 to 31 December 2008 without a history of atherosclerotic cardiovascular disease.

MAIN OUTCOME MEASURES

The primary outcome was the first diagnosis of gastrointestinal cancer (either CRC, GC or EC) and the secondary outcome was GIB. Individuals were followed from index date of prescription until the earliest occurrence of an outcome of interest, an incident diagnosis of any type of cancer besides the outcome, death or until 31 December 2017. A competing risk survival analysis was used to estimate HRs and 95% CIs with death as the competing risk.

RESULTS

After matching, 49 679 aspirin and non-aspirin users were included. The median (IQR) follow-up was 10.0 (6.4) years. HRs for low-dose aspirin compared with non-aspirin users were 0.83 for CRC (95% CI, 0.76 to 0.91), 0.77 for GC (95% CI, 0.65 to 0.92) and 0.88 for EC (95% CI, 0.67 to 1.16). Patients prescribed low-dose aspirin had an increased risk of GIB (HR 1.15, 95% CI, 1.11 to 1.20), except for patients prescribed proton pump inhibitors or histamine H2-receptor antagonists (HR 1.03, 95% CI, 0.96 to 1.10).

CONCLUSION

In this cohort study of Chinese adults, patients prescribed low-dose aspirin had reduced risks of CRC and GC and an increased risk of GIB. Among the subgroup of patients prescribed gastroprotective agents at baseline, however, the association with GIB was attenuated.

Analysis of Platelet Count and New Cancer Diagnosis Over a 10-Year Period

IMPORTANCE

Individuals with cancer often have an elevated platelet count at the time of diagnosis. The extent to which an elevated platelet count is an indicator of cancer is unclear.

OBJECTIVE

To evaluate the association of an elevated platelet count with a cancer diagnosis.

DESIGN, SETTING, AND PARTICIPANTS

This nested case-control study included Ontario residents enrolled in the provincial health insurance plan who had 1 or more routine complete blood count (CBC) tests performed between January 1, 2007, and December 31, 2017, with follow-up through December 31, 2018. Case patients were individuals with a new cancer diagnosis during the observation period. Eligible control individuals were cancer free before the date of diagnosis for a case patient to whom they were matched. One case patient was matched to 3 controls based on sex, age, and health care use patterns. Data were analyzed from September 24, 2020, to July 13, 2021.

EXPOSURES

Case patients and controls were assigned to 1 of 5 exposure groups based on age- and sex-specific platelet count distributions in the control population: very low (≤10th percentile), low (>10th to 25th percentile), medium (>25th to <75th percentile), high (75th to <90th percentile), and very high (≥90th percentile).

MAIN OUTCOMES AND MEASURES

Odds ratios (ORs) were estimated for specific cancer sites for each category of platelet count at intervals up to 10 years after a blood test.

RESULTS

Of the 8 917 187 eligible Ontario residents with a routine CBC record available, 4 971 578 (55.8%) were women; the median age at the first CBC was 46.4 years (IQR, 32.5-59.5 years). Among individuals with a routine CBC record available, 495 341 (5.6%) received a diagnosis of first primary cancer during the 10-year observation period. The OR for a solid tumor diagnosis associated with a very high platelet count vs a medium platelet count in the 6-month period before the diagnosis was 2.32 (95% CI, 2.28-2.35). A very high platelet count was associated with colon (OR, 4.38; 95% CI, 4.22-4.54), lung (OR, 4.37; 95% CI, 4.22-4.53), ovarian (OR, 4.62; 95% CI, 4.19-5.09), and stomach (OR, 4.27; 95% CI, 3.91-4.66) cancers. Odds ratios attenuated with increasing time from CBC test to cancer diagnosis.

CONCLUSIONS AND RELEVANCE

In this nested case-control study, an elevated platelet count was associated with increased risk of cancer at several sites. Our findings suggest that an elevated platelet count could potentially serve as a marker for the presence of some cancer types.

Aspirin use for cancer prevention: A systematic review of public, patient and healthcare provider attitudes and adherence behaviours

We undertook a systematic review to synthesise the data on attitudes and behaviour towards the use of aspirin for cancer prevention, and healthcare providers' attitudes towards implementing aspirin in practice. Searches were carried out across 12 databases (e.g. MEDLINE, EMBASE). We used the Mixed Methods Appraisal Tool to evaluate study quality, and conducted a narrative synthesis of the data. The review was pre-registered (PROSPERO: CRD42018093453). Thirty-eight studies were identified. Uptake and adherence data were all from trials. Trials recruited healthy participants, those at higher risk of cancer, and those with cancer. Four studies reported moderate to high (40.9-77.7%) uptake to an aspirin trial among people who were eligible. Most trials (18/22) reported high day-to-day adherence (≥80%). Three trials observed no association between gender and adherence. One trial found no association between adherence and colorectal cancer risk. Three studies reported moderate to high (43.6-76.0%) hypothetical willingness to use aspirin. Two studies found that a high proportion of healthcare providers (72.0-76.0%) perceived aspirin to be a suitable cancer prevention option. No qualitative studies were identified. The likelihood that eligible users of aspirin would participate in a trial evaluating the use of aspirin for preventive therapy was moderate to high. Among participants in a trial, day-to-day adherence was high. Further research is needed to identify uptake and adherence rates in routine care, the factors affecting aspirin use, and the barriers to implementing aspirin into clinical care.

Long-Term Statin Use, Total Cholesterol Level, and Risk of Colorectal Cancer: A Prospective Cohort Study

INTRODUCTION

Statin use has been examined as a potential chemopreventive strategy against colorectal cancer (CRC). Previous studies have not been able to investigate this topic with adequate follow-up time or disentangle the effects of statin use and total cholesterol level. We investigated prospectively this topic.

METHODS

Eligible participants (100,300 women and 47,991 men) in the Nurses' Health Study and Health Professionals Follow-Up Study were followed for up to 24 years. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals.

RESULTS

We documented 2,924 incident CRC cases during follow-up. In fully adjusted analyses, longer duration of statin use was associated with higher risk of colon cancer (hazard ratios, the 95% confidence interval was 1.09, 0.95-1.25 for 1-5 years; 1.16, 0.99-1.36 for 6-10 years; 1.08, 0.81-1.44 for 11-15 years; 1.85, 1.30-2.61 for >15 years; vs never users, P = 0.004 for trend) rather than rectal cancer. The risk elevation was driven by proximal colon cancer (1.16, 0.98-1.38 for 1-5 years; 1.19, 0.98-1.45 for 6-10 years; 1.25, 0.89-1.74 for 11-15 years; 2.17, 1.46-3.24 for >15 years; vs never users, P = 0.001 for trend) rather than distal colon cancer. The results remained robust in analyses among participants with hypercholesterolemia or who never received screening. Total cholesterol level was not associated with CRC risk.

DISCUSSION

This study does not support benefit of statin use in CRC chemoprevention or any association between total cholesterol level and CRC risk. On the contrary, long-term statin use may be associated with increased colon cancer risk (driven by proximal colon cancer).

Aspirin, metformin, and statin use on the risk of gastric cancer: A nationwide population-based cohort study in Korea with systematic review and meta-analysis

BACKGROUND/AIMS

Although several chemopreventive drugs against gastric cancer have been proposed, their effects have not been fully evaluated. We examined the impacts of aspirin, metformin, and statin use on gastric cancer development in a population-based cohort in Korea.

METHODS

We analyzed the association between potential chemopreventive drugs-aspirin, metformin, and statin-and gastric cancer through the Observational Medical Outcomes Partnership Common Data Model-based Korean nationwide cohort. Use of aspirin, metformin, and statin was defined by ≥365 days of prescriptions for each drug in the general population. To summarize the current evidence, we further performed a systematic review and meta-analysis of the impact of aspirin, metformin, and statin on gastric cancer development.

RESULTS

After propensity score matching, 31,839, 6764, and 10,251 subjects were observed for medians of 4.7, 4.2, and 4.2 years for aspirin, metformin, and statin analysis, respectively. Use of aspirin or statin was associated with lower risks of gastric cancer compared to their non-use, respectively (hazard ratio [HR] [95% confidence interval [CI]]: aspirin, 0.72 [0.60-0.85], p < 0.01; statin, 0.67 [0.49-0.92], p = 0.01). However, no association was observed between metformin use and gastric cancer development (HR [95% CI]: 0.85 [0.59-1.23], p = 0.40). A subgroup of subjects with diabetes mellitus showed a lower risk of gastric cancer development with statin use. The meta-analysis showed the highest effect size of gastric cancer development for statin, followed by aspirin and metformin.

CONCLUSIONS

Statin and aspirin use were associated with significantly reduced risks of gastric cancer development, while the use of metformin was not associated with the gastric cancer risk. The protective effect of statin against gastric cancer was also significant in patients with diabetes mellitus.

Salicylic Acid and Risk of Colorectal Cancer: A Two-Sample Mendelian Randomization Study

Salicylic acid (SA) has observationally been shown to decrease colorectal cancer (CRC) risk. Aspirin (acetylsalicylic acid, that rapidly deacetylates to SA) is an effective primary and secondary chemopreventive agent. Through a Mendelian randomization (MR) approach, we aimed to address whether levels of SA affected CRC risk, stratifying by aspirin use. A two-sample MR analysis was performed using GWAS summary statistics of SA (INTERVAL and EPIC-Norfolk, N = 14,149) and CRC (CCFR, CORECT, GECCO and UK Biobank, 55,168 cases and 65,160 controls). The DACHS study (4410 cases and 3441 controls) was used for replication and stratification of aspirin-use. SNPs proxying SA were selected via three methods: (1) functional SNPs that influence the activity of aspirin-metabolising enzymes; (2) pathway SNPs present in enzymes' coding regions; and (3) genome-wide significant SNPs. We found no association between functional SNPs and SA levels. The pathway and genome-wide SNPs showed no association between SA and CRC risk (OR: 1.03, 95% CI: 0.84-1.27 and OR: 1.08, 95% CI: 0.86-1.34, respectively). Results remained unchanged upon aspirin use stratification. We found little evidence to suggest that an SD increase in genetically predicted SA protects against CRC risk in the general population and upon stratification by aspirin use.

Clinical Applications of Aspirin as a Multi-potent Drug Beyond Cardiovascular Implications: A Proof of Concept for Anesthesiologists- A Narrative Review

To the best of our knowledge, aspirin (ASA) is known as a commonly used medication worldwide. Although the cardiovascular aspects of ASA are well-established, recently, it has been identified that ASA can yield multiple extra-cardiovascular therapeutic potencies in facing neurodegenerative disorders, various cancers, inflammatory responses, and the COVID-19 pandemic. In this review, we aimed to highlight the proven role of ASA administration in the variety of non-cardiovascular diseases, particularly in the field of anesthesiology.

Low-dose Aspirin for Primary Prevention of Cardiovascular Events in Postmenopausal Women with Type-2 Diabetes: The Prescriptive Approach in the Real World

BACKGROUND

The long-term efficacy of low-dose aspirin for primary prevention of cardiovascular (CV) events in postmenopausal women with type-2 diabetes is controversial. Therefore, it is recommended only on an individual basis, recommendation of grade C.

METHODS

We enrolled 275 consecutive postmenopausal women with type-2 diabetes, without an increased bleeding risk and without preexisting CV disease as coronary artery disease, stroke, and peripheral vascular disease, but with a high risk assessed by score >10%, aged 60-69 years. All were receiving aspirin (75-100 mg daily), aspirin group (AG). 170 postmenopausal women with type-2 diabetes and without preexisting cardiovascular (CV) disease, but not on aspirin treatment, despite a high risk assessed by score >10%, were control group (CG). Mean age was 66 ± 4 years for AG and 65 ± 7 years for CG. Our goal was to identify the prevalence of low-dose aspirin prescriptions in these populations according to different clinical conditions.

RESULTS

Women with only high risk were 41/275 (15%) on AG and 72/170 (42.3%) on CG, Chi-squared 41, Odds ratio 0.2, c.i. 95%, P < 0.0001. Women affected by metabolic syndrome were 105/275 (38.1%) on AG and 47/170 (27.6%) on CG, Chi-squared 5.1, Odds ratio 1.6, c.i. 95%, P < 0.02. Women affected by metabolic cardiomyopathy were 111/275 (40.3%) on AG and 44/170 (25.9%) on CG, Chi-squared 8, Odds ratio 1.8, c.i. 95%, P < 0.004. Women affected by diabetic cardiomyopathy were 18/275 (6.6%) on AG and 7/170 (4.2%) on CG, Chi-squared 1.2, Odds ratio 16, c.i. 95%, P < 0.2 n.s.

CONCLUSIONS

Low-dose aspirin in our population is prescribed preferentially in postmenopausal women with type-2 diabetes when affected by metabolic syndrome or metabolic cardiomyopathy, at the opposite women with only high risk have lower chance to receive aspirin.

Short-term aspirin and statin chemoprophylaxis did not reduce the risk of developing advanced adenomatous polyps in Black patients

BACKGROUND

Chemoprevention of colorectal neoplasia with aspirin and statins is under-investigated in Black patients. Since Black patients suffer disproportionately from colon cancer incidence and mortality compared to other populations, we investigated the utility of aspirin and statin in reducing advanced adenomatous polyp (AAP) risk in Black patients.

METHODS

We carried out a retrospective cohort study of screening colonoscopies performed at a large urban academic center from 1/1/2011 through 12/31/2019. We analyzed self-identified Black patients with > 1 colonoscopy and no personal history of either inflammatory bowel disease or colon cancer syndromes. Our primary endpoint was first AAP development after index colonoscopy among Black patients taking both aspirin and a statin compared to those taking one or neither medication. We used multivariate logistic regression modeling to investigate our outcomes.

RESULTS

We found data on chemoprophylaxis use in 560 patients. The mean observation period between index colonoscopy and AAP identification was 4 years. AAP developed in 106/560 (19%) of our cohort. We found no difference in AAP risk among Black patients taking both chemoprevention medications compared to partial or no chemoprophylaxis (20% vs 18% respectively, p = 0.49). This finding remained after adjusting for age, body mass index, and tobacco use (odds ratio 1.04, 95% CI 0.65-1.67; p = 0.87).

CONCLUSIONS

Short-term aspirin-statin chemoprevention did not reduce the risk of AAP development in our cohort of Black patients. Larger and long-term prospective investigations are needed to investigate the utility of chemoprophylaxis in this population.

TRIAL REGISTRATION

Not applicable.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Aspirin, ibuprofen, and reduced risk of advanced colorectal adenoma incidence and recurrence and colorectal cancer in the PLCO Cancer Screening Trial

BACKGROUND

Studying the differential impact of aspirin and other nonsteroidal anti-inflammatory drugs across the stages of colorectal neoplasia from early adenoma to cancer is critical for understanding the benefits of these widely used drugs.

METHODS

With 13 years of follow-up, the authors prospectively evaluated the association between aspirin and ibuprofen use and incident distal adenoma (1221 cases), recurrent adenoma (862 cases), and incident colorectal cancer (CRC; 2826 cases) among men and women in the population-based Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. With multivariable-adjusted models, odds ratio (ORs) and 95% confidence intervals (CIs) for adenoma incidence and recurrence and hazard ratios (HRs) and 95% CIs for incident CRC were determined.

RESULTS

The authors observed a significantly reduced risk of incident adenoma with ibuprofen use (≥30 vs <4 pills per month: OR, 0.76 [95% CI, 0.60-0.95]; Ptrend = .04), particularly advanced adenoma (OR, 0.48 [95% CI, 0.28-0.83]; Ptrend = .005). Among those with a previous adenoma detected through screening, aspirin use was associated with a decreased risk of advanced recurrent adenoma (≥30 vs <4 pills per month: OR, 0.56 [95% CI, 0.36-0.87]; Ptrend = 0.006). Both aspirin (HR, 0.88 [95% CI, 0.81-0.96]; Ptrend <.0001) and ibuprofen use (HR, 0.81 [95% CI, 0.70-0.93); Ptrend = 0.003) ≥30 versus <4 pills per month were significantly associated with reduced CRC risk.

CONCLUSIONS

In this large prospective study with long-term follow-up, a beneficial role for not only aspirin, but also ibuprofen, in preventing advanced adenoma and curbing progression to recurrence and cancer among older adults was observed.

Does aspirin reduce the incidence, recurrence, and mortality of colorectal cancer? A meta-analysis of randomized clinical trials

BACKGROUND

Colorectal cancer (CRC) is the third most common diagnosed cancer and the third leading cause of all cancer deaths in the USA. Some evidences are shown that aspirin can reduce the morbidity and mortality of different cancers, including CRC. Aspirin has become a new focus of cancer prevention and treatment research so far; clinical studies, however, found conflicting conclusions of its anti-cancer characteristics. This study is to summarize the latest evidence of correlation between aspirin use and CRC and/or colorectal adenomas.

METHODS

Databases were searched to identify randomized controlled trials (RCTs) in the salvage setting. The pooled relative risk (RR) with 95% confidence interval (CI) was used to estimate the effect of aspirin on colorectal cancer and/or colorectal adenomas. Subgroup analysis and sensitivity analysis were also conducted.

RESULTS

The result showed that aspirin use was not associated with incidence of CRC (RR 0.97; 95% CI 0.84-1.12; P = 0.66; I² = 34%), aspirin use was found to be associated with reduced recurrence of colorectal adenomas (RR 0.83; 95% CI 0.72-0.95; P = 0.006; I² = 63%) and reduced mortality of CRC (RR 0.79; 95% CI 0.64-0.97; P = 0.02; I² = 14%). Subgroup analysis found a statistically significant association in low dose with a pooled RR of 0.85 (95% CI 0.74-0.99; P = 0.03; I² = 31%).

CONCLUSIONS

This meta-analysis of randomized controlled trial data indicates that aspirin reduces the overall risk of recurrence and mortality of CRC and/or colorectal adenomas. Incidence of CRC was also reduced with low-dose aspirin. The emerging evidence on aspirin's cancer protection role highlights an exciting time for cancer prevention through low-cost interventions.

TRIAL REGISTRATION

Clinicaltrials.gov no: CRD42020208852; August 18, 2020; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020208852 ).

Influence of aspirin on prevention of colorectal cancer: an updated systematic review and meta-analysis of randomized controlled trials

PURPOSE

Colorectal cancer is the second most common cause of cancer death worldwide. Aspirin, due to its antineoplastic effects, has been suggested to have chemopreventive effects on colorectal cancer based on recent trials. We conducted this systematic review and meta-analysis to provide an updated evidence about the long-term efficacy of daily aspirin use in the prevention of colorectal cancer.

METHODS

We searched Medline/PubMed, Ovid, Web of Science, and Cochrane Library. We included randomized controlled trials (RCTs) that compared the efficacy of daily aspirin use to placebo in healthy individuals at the time of study entry. The desired outcomes of this review were the incidence of advanced lesions (i.e., adenomas with villous component, adenomas ≥1 cm in diameter, adenomas with high-grade dysplasia, and/or invasive cancer) and colorectal adenomas.

RESULTS

A total of 15 articles representing 11 RCTs were included. Overall, the results indicated that aspirin significantly reduced the risk of developing colorectal adenomas but not advanced lesions at 3 years (risk ratio (RR) = 0.84, P < 0.05 and risk ratio = 0.82, P = 0.10, respectively). At 5 years, the risk of advanced lesions but not adenomas was reduced by aspirin (RR = 0.68, P < 0.05 and RR = 0.87, P = 0.22, respectively). Aspirin was not found to have an effect on the risk of advanced lesions or adenomas beyond 5 years (hazard ratio (HR) = 0.82, P = 0.07 and HR = 0.99, P = 0.82, respectively).

CONCLUSION

Overall, aspirin (particularly high dose) only reduced the risk of advanced lesions up to 5 years.

Timing of Aspirin Use in Colorectal Cancer Chemoprevention: A Prospective Cohort Study

BACKGROUND

Prior epidemiological and intervention studies have not been able to separate independent effects of dose, timing, and duration of aspirin use in colorectal cancer (CRC) chemoprevention. We examined aspirin-based CRC chemoprevention according to timing in the Nurses' Health Study and Health Professionals Follow-Up Study.

METHODS

The exposures include cumulative average dose and total duration of aspirin use in more than 10 years before follow-up started (remote period) and in the immediate 10 years before follow-up started (recent period). Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for exposures and CRC risk.

RESULTS

Aspirin use of longer than 10 years before follow-up started (HR = 0.88, 95% CI = 0.83 to 0.94) per 5-year increment and the immediate 10 years before follow-up started (HR = 0.90, 95% CI = 0.84 to 0.96) were similarly important in CRC chemoprevention, though a 5-year lag was required for a clear benefit in the recent period. In the remote period, the association was not dose dependent; compared with less than 0.5 standard-dose (325 mg) tablets per week; hazard ratios were 0.78 (95% CI = 0.63 to 0.98), 0.81 (95% CI = 0.72 to 0.91), and 0.74 (95% CI = 0.64 to 0.86) for doses of 0.5 to less than 1.5, 1.5 to less than 5, and 5 and more tablets per week, respectively. However, there was dose dependency in the recent period (with respective HR = 0.91, 95% CI = 0.79 to 1.06; HR = 0.87, 95% CI = 0.77 to 0.98; and HR = 0.76, 95% CI = 0.64 to 0.91).

CONCLUSIONS

A suggestive benefit necessitates at least 6-10 years and most clearly after approximately 10 years since initiation of aspirin. Remote use and use within the previous 10 years both contribute independently to decrease risk, though a lower dose may be required for a benefit with longer term use.

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

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

Combined Use of Aspirin and Selective Serotonin Reuptake Inhibitors Is Associated With Lower Risk of Colorectal Cancer: A Nested Case-Control Study

INTRODUCTION

Chemoprevention against colorectal cancer (CRC) is greatly needed. As the development of CRC involves multiple dysfunctional pathways, it is thus reasonable to combine some agents that address several pathways to achieve better chemoprotection. We aimed to explore whether the use of aspirin and selective serotonin reuptake inhibitors (SSRIs)-either as monotherapy or combined-can have a clinical benefit against CRC.

METHODS

We performed a nested case-control study using nationwide Swedish registers. We recruited 24,786 CRC cases and randomly matched to 74,358 controls conditional on birth year and sex using incidence-density sampling. The conditional logistic regression model was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Additive interaction was calculated as the relative excess risk for interaction, and multiplicative interaction was calculated by including a product term in the regression model.

RESULTS

Both aspirin and SSRIs monotherapy were negatively associated with CRC risk, but the combined use of aspirin and SSRIs was associated with an even lower CRC risk (adjusted OR, 0.77, 95% CI, 0.67-0.89) than aspirin monotherapy (adjusted OR, 0.91, 95% CI, 0.87-0.97) or SSRI monotherapy (adjusted OR, 0.93, 95% CI, 0.86-1.00). A significant interaction was observed at the additive scale with a relative excess risk for interaction of -0.07 (P < 0.001), whereas no interaction was noted on the interactive scale. The inverse associations of CRC with aspirin and SSRIs showed a dose-dependent pattern.

DISCUSSION

This study suggests that the use of aspirin and SSRIs-either as monotherapy or combined-was associated with a reduced risk of CRC. The stronger chemoprevention of combined use of aspirin and SSRIs is innovative and calls for further studies to confirm the underlying mechanisms and the plausibility of clinical recommendation.

European guidelines from the EHTG and ESCP for Lynch syndrome: an updated third edition of the Mallorca guidelines based on gene and gender

BACKGROUND

Lynch syndrome is the most common genetic predisposition for hereditary cancer but remains underdiagnosed. Large prospective observational studies have recently increased understanding of the effectiveness of colonoscopic surveillance and the heterogeneity of cancer risk between genotypes. The need for gene- and gender-specific guidelines has been acknowledged.

METHODS

The European Hereditary Tumour Group (EHTG) and European Society of Coloproctology (ESCP) developed a multidisciplinary working group consisting of surgeons, clinical and molecular geneticists, pathologists, epidemiologists, gastroenterologists, and patient representation to conduct a graded evidence review. The previous Mallorca guideline format was used to revise the clinical guidance. Consensus for the guidance statements was acquired by three Delphi voting rounds.

RESULTS

Recommendations for clinical and molecular identification of Lynch syndrome, surgical and endoscopic management of Lynch syndrome-associated colorectal cancer, and preventive measures for cancer were produced. The emphasis was on surgical and gastroenterological aspects of the cancer spectrum. Manchester consensus guidelines for gynaecological management were endorsed. Executive and layperson summaries were provided.

CONCLUSION

The recommendations from the EHTG and ESCP for identification of patients with Lynch syndrome, colorectal surveillance, surgical management of colorectal cancer, lifestyle and chemoprevention in Lynch syndrome that reached a consensus (at least 80 per cent) are presented.

The diverse molecular profiles of lynch syndrome-associated colorectal cancers are (highly) dependent on underlying germline mismatch repair mutations

Lynch syndrome (LS) is a hereditary cancer syndrome that accounts for 3% of all new colorectal cancer (CRC) cases. Patients carry a germline pathogenic variant in one of the mismatch repair (MMR) genes (MLH1, MSH2, MSH6 or PMS2), which encode proteins involved in a post-replicative proofreading and editing mechanism. The clinical presentation of LS is highly heterogeneous, showing high variability in age at onset and penetrance of cancer, which may be partly attributable to the molecular profiles of carcinomas. This review discusses the frequency of alterations in the WNT/B-CATENIN, RAF/MEK/ERK and PI3K/PTEN/AKT pathways identified in all four LS subgroups and how these changes may relate to the 'three pathway model' of carcinogenesis, in which LS CRCs develop from MMR-proficient adenomas, MMR-deficient adenomas or directly from MMR-deficient crypts. Understanding the specific differences in carcinogenesis for each LS subgroup will aid in the further optimization of guidelines for diagnosis, surveillance and treatment.

Aspirin and antiplatelet treatments in cancer

Platelets have been hypothesized to promote certain neoplastic malignancies; however, antiplatelet drugs are still not part of routine pharmacological cancer prevention and treatment protocols. Paracrine interactions between platelets and cancer cells have been implicated in potentiating the dissemination, survival within the circulation, and extravasation of cancer cells at distant sites of metastasis. Signals from platelets have also been suggested to confer epigenetic alterations, including upregulating oncoproteins in circulating tumor cells, and secretion of potent growth factors may play roles in promoting mitogenesis, angiogenesis, and metastatic outgrowth. Thrombocytosis remains a marker of poor prognosis in patients with solid tumors. Experimental data suggest that lowering of platelet count may reduce tumor growth and metastasis. On the basis of the mechanisms by which platelets could contribute to cancer growth and metastasis, it is conceivable that drugs reducing platelet count or platelet activation might attenuate cancer progression and improve outcomes. We will review select pharmacological approaches that inhibit platelets and may affect cancer development and propagation. We begin by presenting an overview of clinical cancer prevention and outcome studies with low-dose aspirin. We then review current nonclinical development of drugs targeted to platelet binding, activation, and count as potential mitigating agents in cancer.

Aspirin at 120: Retiring, recombining, or repurposing?

During the past 20 years, we have witnessed the following trends in aspirin usage: (i) a "dropping" trend, characterized by the early discontinuation of low-dose aspirin from dual antiplatelet therapy or triple antithrombotic therapy (oral anticoagulation plus dual antiplatelet therapy in patients with atrial fibrillation) following an acute coronary syndrome or after percutaneous coronary intervention; (ii) a "combinatorial" trend, featuring the addition of a lower dose of a P2Y12 inhibitor or direct oral anticoagulant drug to low-dose aspirin for the long-term treatment of stable patients with atherosclerotic cardiovascular disease; and (iii) a "repurposing" trend, characterized by growing interest in the oncologic community to assess the chemopreventive effect of aspirin against certain types of cancers (particularly of the gastrointestinal tract), both as primary prevention and adjuvant therapy. The aim of this review is to present the mechanistic rationale underlying these trends, discuss the design and findings of trials testing novel treatments or new therapeutic applications of aspirin, and report on the ISTH Congress results on this topic.

A meta-analysis of the correlation between non-steroidal anti-inflammatory drugs and recurrent colorectal adenomatous polyps

AIM

The purpose of this study was to evaluate the effect of non-steroidal anti-inflammatory drugs (NSAIDs) on the recurrence risk of colorectal adenomas through a meta-analysis of published studies.

METHODS

A meta-analysis was performed to evaluate the effect of NSAIDs on the incidence rates of colorectal adenomatous polyps, using PubMed, Ovid, Elsevier, and other journal databases. Data were processed using Review Manager 5.3 and random errors were calculated using trial sequential analysis (TSA).

RESULTS

A total of 8 studies published between 2003 and 2014 were selected. In the data collected, the patients on long-term usage of low-dose NSAIDs were shown to have significantly lower risk of colorectal adenoma compared with those on placebos (RR=0.80, 95% CI=0.70-0.92), with relatively low random errors. Long-term usage of low-dose NSAIDs was also found to have inhibitory effects on advanced adenomas (RR=0.66, 95% CI=0.44-0.99), but with relatively high random errors. Besides, high-dose NSAIDs were also shown to have inhibitory but inconsistent effects on adenomas and advanced adenomas (RR=0.66, 95% CI=0.59-0.72), and the withdrawal was associated with increased risks of the disease.

CONCLUSION

These results suggest that low-dose NSAIDs have an inhibitory effect on recurrent adenomas, but the efficacy for late-stage adenomas remain inconclusive. The withdrawal of the drug might be associated with increased risks of the disease.

Patient Preferences of Low-Dose Aspirin for Cardiovascular Disease and Colorectal Cancer Prevention in Italy: A Latent Class Analysis

Background

Patients taking low-dose aspirin to prevent cardiovascular disease (CVD) may also benefit from a reduced risk of colorectal cancer (CRC).

Objective

The aim was to examine the preferences of people eligible for preventive treatment with low-dose aspirin and the trade-offs they are willing to make between CVD prevention, CRC prevention, and treatment risks.

Methods

A cross-sectional study using a discrete choice experiment (DCE) survey was conducted in Italy in 2019 to elicit preferences for three benefit attributes (prevention of ischemic stroke, myocardial infarction, and CRC) and four risk attributes (intracranial and gastrointestinal bleeding, peptic ulcer, and severe allergic reaction) associated with use of low-dose aspirin. Latent class logit models were used to evaluate variation in treatment preferences.

Results

The DCE survey was completed by 1005 participants eligible for use of low-dose aspirin. A four-class model had the best fit for the primary CVD prevention group (n = 491), and a three-class model had the best fit for the secondary CVD prevention group (n = 514). For the primary CVD prevention group, where classes differed on age, education level, type 2 diabetes, exercise, and low-dose aspirin use, the most important attributes were intracranial bleeding (two classes), myocardial infarction (one class), and CRC (one class). For the secondary CVD prevention group, where classes differed on various comorbidities, self-reported health, exercise, and CVD medication use, the most important attributes were intracranial bleeding (two classes), myocardial infarction (one class), and gastrointestinal bleeding (one class).

Conclusion

Patient preferences for the benefits and risks of low-dose aspirin differ significantly among people eligible for treatment as primary or secondary CVD prevention.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40271-021-00506-2.

Antiplatelet Drug Use and Breast Cancer Risk in a Prospective Cohort of Postmenopausal Women

BACKGROUND

Epidemiologic evidence is insufficient to draw conclusions on the impact of low-dose aspirin use on breast cancer risk, and the potential impact of other antiplatelet drugs such as clopidogrel needs to be explored.

METHODS

We investigated the association between breast cancer risk and low-dose aspirin or clopidogrel use in the E3N cohort, which includes 98,995 women, with information on breast cancer risk factors collected from biennial questionnaires matched with drug reimbursement data available from 2004. Women with at least two reimbursements of the drug of interest in any previous 3-month period were considered "ever" exposed. Exposure was considered as time-varying and multivariable Cox regression models were used to estimate HRs of breast cancer.

RESULTS

Among 62,512 postmenopausal women followed during 9 years on average, 2,864 breast cancer cases were identified. Compared with never use, a transient higher breast cancer risk was observed during the third year of low-dose aspirin use [HR2-≤3 years of use = 1.49 (1.08-2.07)], followed by a lower risk [HR4+ years of use = 0.72 (0.52-0.99)]. Clopidogrel ever use was associated with a higher breast cancer risk [HR, 1.30 (1.02-1.68)], restricted to estrogen receptor negative (ER-) tumors [HRER+ = 1.14 (0.83-1.57), HRER- = 3.07 (1.64-5.76), P homogeneity = 0.01].

CONCLUSIONS

Low-dose aspirin was associated with a lower breast cancer risk only after several years of use, while ever use of clopidogrel was associated with a higher ER- breast cancer risk.

IMPACT

Antiplatelet drugs are not good pharmacologic candidates for breast cancer prevention.