Summary Background High-dose aspirin (≥500 mg daily) reduces long-term incidence of colorectal cancer, but adverse effects might limit its potential for long-term prevention. The long-term ...effectiveness of lower doses (75–300 mg daily) is unknown. We assessed the effects of aspirin on incidence and mortality due to colorectal cancer in relation to dose, duration of treatment, and site of tumour. Methods We followed up four randomised trials of aspirin versus control in primary (Thrombosis Prevention Trial, British Doctors Aspirin Trial) and secondary (Swedish Aspirin Low Dose Trial, UK-TIA Aspirin Trial) prevention of vascular events and one trial of different doses of aspirin (Dutch TIA Aspirin Trial) and established the effect of aspirin on risk of colorectal cancer over 20 years during and after the trials by analysis of pooled individual patient data. Results In the four trials of aspirin versus control (mean duration of scheduled treatment 6·0 years), 391 (2·8%) of 14 033 patients had colorectal cancer during a median follow-up of 18·3 years. Allocation to aspirin reduced the 20-year risk of colon cancer (incidence hazard ratio HR 0·76, 0·60–0·96, p=0·02; mortality HR 0·65, 0·48–0·88, p=0·005), but not rectal cancer (0·90, 0·63–1·30, p=0·58; 0·80, 0·50–1·28, p=0·35). Where subsite data were available, aspirin reduced risk of cancer of the proximal colon (0·45, 0·28–0·74, p=0·001; 0·34, 0·18–0·66, p=0·001), but not the distal colon (1·10, 0·73–1·64, p=0·66; 1·21, 0·66–2·24, p=0·54; for incidence difference p=0·04, for mortality difference p=0·01). However, benefit increased with scheduled duration of treatment, such that allocation to aspirin of 5 years or longer reduced risk of proximal colon cancer by about 70% (0·35, 0·20–0·63; 0·24, 0·11–0·52; both p<0·0001) and also reduced risk of rectal cancer (0·58, 0·36–0·92, p=0·02; 0·47, 0·26–0·87, p=0·01). There was no increase in benefit at doses of aspirin greater than 75 mg daily, with an absolute reduction of 1·76% (0·61–2·91; p=0·001) in 20-year risk of any fatal colorectal cancer after 5-years scheduled treatment with 75–300 mg daily. However, risk of fatal colorectal cancer was higher on 30 mg versus 283 mg daily on long-term follow-up of the Dutch TIA trial (odds ratio 2·02, 0·70–6·05, p=0·15). Interpretation Aspirin taken for several years at doses of at least 75 mg daily reduced long-term incidence and mortality due to colorectal cancer. Benefit was greatest for cancers of the proximal colon, which are not otherwise prevented effectively by screening with sigmoidoscopy or colonoscopy. Funding None.
Summary Background Daily aspirin reduces the long-term incidence of some adenocarcinomas, but effects on mortality due to some cancers appear after only a few years, suggesting that it might also ...reduce growth or metastasis. We established the frequency of distant metastasis in patients who developed cancer during trials of daily aspirin versus control. Methods Our analysis included all five large randomised trials of daily aspirin (≥75 mg daily) versus control for the prevention of vascular events in the UK. Electronic and paper records were reviewed for all patients with incident cancer. The effect of aspirin on risk of metastases at presentation or on subsequent follow-up (including post-trial follow-up of in-trial cancers) was stratified by tumour histology (adenocarcinoma vs other) and clinical characteristics. Findings Of 17 285 trial participants, 987 had a new solid cancer diagnosed during mean in-trial follow-up of 6·5 years (SD 2·0). Allocation to aspirin reduced risk of cancer with distant metastasis (all cancers, hazard ratio HR 0·64, 95% CI 0·48–0·84, p=0·001; adenocarcinoma, HR 0·54, 95% CI 0·38–0·77, p=0·0007; other solid cancers, HR 0·82, 95% CI 0·53–1·28, p=0·39), due mainly to a reduction in proportion of adenocarcinomas that had metastatic versus local disease (odds ratio 0·52, 95% CI 0·35–0·75, p=0·0006). Aspirin reduced risk of adenocarcinoma with metastasis at initial diagnosis (HR 0·69, 95% CI 0·50–0·95, p=0·02) and risk of metastasis on subsequent follow-up in patients without metastasis initially (HR 0·45, 95% CI 0·28–0·72, p=0·0009), particularly in patients with colorectal cancer (HR 0·26, 95% CI 0·11–0·57, p=0·0008) and in patients who remained on trial treatment up to or after diagnosis (HR 0·31, 95% CI 0·15–0·62, p=0·0009). Allocation to aspirin reduced death due to cancer in patients who developed adenocarcinoma, particularly in those without metastasis at diagnosis (HR 0·50, 95% CI 0·34–0·74, p=0·0006). Consequently, aspirin reduced the overall risk of fatal adenocarcinoma in the trial populations (HR 0·65, 95% CI 0·53–0·82, p=0·0002), but not the risk of other fatal cancers (HR 1·06, 95% CI 0·84–1·32, p=0·64; difference, p=0·003). Effects were independent of age and sex, but absolute benefit was greatest in smokers. A low-dose, slow-release formulation of aspirin designed to inhibit platelets but to have little systemic bioavailability was as effective as higher doses. Interpretation That aspirin prevents distant metastasis could account for the early reduction in cancer deaths in trials of daily aspirin versus control. This finding suggests that aspirin might help in treatment of some cancers and provides proof of principle for pharmacological intervention specifically to prevent distant metastasis. Funding None.
Summary Background Treatment with daily aspirin for 5 years or longer reduces subsequent risk of colorectal cancer. Several lines of evidence suggest that aspirin might also reduce risk of other ...cancers, particularly of the gastrointestinal tract, but proof in man is lacking. We studied deaths due to cancer during and after randomised trials of daily aspirin versus control done originally for prevention of vascular events. Methods We used individual patient data from all randomised trials of daily aspirin versus no aspirin with mean duration of scheduled trial treatment of 4 years or longer to determine the effect of allocation to aspirin on risk of cancer death in relation to scheduled duration of trial treatment for gastrointestinal and non-gastrointestinal cancers. In three large UK trials, long-term post-trial follow-up of individual patients was obtained from death certificates and cancer registries. Results In eight eligible trials (25 570 patients, 674 cancer deaths), allocation to aspirin reduced death due to cancer (pooled odds ratio OR 0·79, 95% CI 0·68–0·92, p=0·003). On analysis of individual patient data, which were available from seven trials (23 535 patients, 657 cancer deaths), benefit was apparent only after 5 years' follow-up (all cancers, hazard ratio HR 0·66, 0·50–0·87; gastrointestinal cancers, 0·46, 0·27–0·77; both p=0·003). The 20-year risk of cancer death (1634 deaths in 12 659 patients in three trials) remained lower in the aspirin groups than in the control groups (all solid cancers, HR 0·80, 0·72–0·88, p<0·0001; gastrointestinal cancers, 0·65, 0·54–0·78, p<0·0001), and benefit increased (interaction p=0·01) with scheduled duration of trial treatment (≥7·5 years: all solid cancers, 0·69, 0·54–0·88, p=0·003; gastrointestinal cancers, 0·41, 0·26–0·66, p=0·0001). The latent period before an effect on deaths was about 5 years for oesophageal, pancreatic, brain, and lung cancer, but was more delayed for stomach, colorectal, and prostate cancer. For lung and oesophageal cancer, benefit was confined to adenocarcinomas, and the overall effect on 20-year risk of cancer death was greatest for adenocarcinomas (HR 0·66, 0·56–0·77, p<0·0001). Benefit was unrelated to aspirin dose (75 mg upwards), sex, or smoking, but increased with age—the absolute reduction in 20-year risk of cancer death reaching 7·08% (2·42–11·74) at age 65 years and older. Interpretation Daily aspirin reduced deaths due to several common cancers during and after the trials. Benefit increased with duration of treatment and was consistent across the different study populations. These findings have implications for guidelines on use of aspirin and for understanding of carcinogenesis and its susceptibility to drug intervention. Funding None.
Summary Background Daily aspirin reduces the long-term risk of death due to cancer. However, the short-term effect is less certain, especially in women, effects on cancer incidence are largely ...unknown, and the time course of risk and benefit in primary prevention is unclear. We studied cancer deaths in all trials of daily aspirin versus control and the time course of effects of low-dose aspirin on cancer incidence and other outcomes in trials in primary prevention. Methods We studied individual patient data from randomised trials of daily aspirin versus no aspirin in prevention of vascular events. Death due to cancer, all non-vascular death, vascular death, and all deaths were assessed in all eligible trials. In trials of low-dose aspirin in primary prevention, we also established the time course of effects on incident cancer, major vascular events, and major extracranial bleeds, with stratification by age, sex, and smoking status. Results Allocation to aspirin reduced cancer deaths (562 vs 664 deaths; odds ratio OR 0·85, 95% CI 0·76–0·96, p=0·008; 34 trials, 69 224 participants), particularly from 5 years onwards (92 vs 145; OR 0·63, 95% CI 0·49–0·82, p=0·0005), resulting in fewer non-vascular deaths overall (1021 vs 1173; OR 0·88, 95% CI 0·78–0·96, p=0·003; 51 trials, 77 549 participants). In trials in primary prevention, the reduction in non-vascular deaths accounted for 87 (91%) of 96 deaths prevented. In six trials of daily low-dose aspirin in primary prevention (35 535 participants), aspirin reduced cancer incidence from 3 years onwards (324 vs 421 cases; OR 0·76, 95% CI 0·66–0·88, p=0·0003) in women (132 vs 176; OR 0·75, 95% CI 0·59–0·94, p=0·01) and in men (192 vs 245; OR 0·77, 95% CI 0·63–0·93, p=0·008). The reduced risk of major vascular events on aspirin was initially offset by an increased risk of major bleeding, but effects on both outcomes diminished with increasing follow-up, leaving only the reduced risk of cancer (absolute reduction 3·13 95% CI 1·44–4·82 per 1000 patients per year) from 3 years onwards. Case-fatality from major extracranial bleeds was also lower on aspirin than on control (8/203 vs 15/132; OR 0·32, 95% CI 0·12–0·83, p=0·009). Interpretation Alongside the previously reported reduction by aspirin of the long-term risk of cancer death, the short-term reductions in cancer incidence and mortality and the decrease in risk of major extracranial bleeds with extended use, and their low case-fatality, add to the case for daily aspirin in prevention of cancer. Funding None.
Aims Respiratory infection may be associated with an increased risk of major cardiovascular events. This case-control study describes associations with these events of respiratory infection. Methods ...and results The IMS Disease Analyzer Mediplus primary care database was used to identify all cases of first-time diagnosis of myocardial infarction (MI) or stroke and single matched controls. Details were extracted on visits for respiratory infection over the preceding year. A total of 11 155 MI cases and 9208 stroke cases were identified. For MI and stroke respectively, there were 326 and 260 respiratory infections during the month preceding the index date. There was strong evidence of an increased risk of both events in the 7 days following infection, for MI adjusted odds ratio (OR) 2.10 (95% confidence interval 1.38–3.21), for stroke OR 1.92 (95% confidence interval 1.24–2.97). The strength of these associations fell over time. The associations for MI occurred at all levels of initial underlying cardiovascular risk. Conclusions There are strong associations between recent respiratory infection and major cardiovascular events, for MI at all levels of underlying risk. The benefits of reducing respiratory infection either through immunization or treating or preventing infection may be substantial.
Background The association between respiratory infection and risk of heart attacks and strokes is well established. However, less evidence exists for an association between respiratory infection and ...venous thromboembolism (VTE). In this article, we describe the associations between respiratory infection and VTE.
Methods All cases aged 18 years of first-time diagnosis of deep-vein thrombosis (DVT) or pulmonary embolism (PE) were identified together with single-matched controls from a primary care general practice database. In addition to the matching characteristics, information was collected on other potentially important confounding factors.
Results There were 457/11 557 (4.0%) DVT cases with respiratory infection in the year before the index date (73 in the preceding month) compared with 262/11 557 (2.3%) controls (24 in the preceding month). There was an increased risk of DVT in the month following infection adjusted odds ratio (OR) = 2.64, 95% confidence interval (95% CI) 1.62-4.29 which persisted up to a year. There were 180/5162 (3.5%) PE cases with respiratory infection in the year before the index date compared with 94/5162 (1.8%) controls excluding those in the preceding month to avoid the possible misdiagnosis of early PE. There was an increased risk of PE in the 3 months following infection (adjusted OR = 2.50, 95% CI 1.33-4.72) which may have persisted up to a year.
Conclusions There are strong associations between recent respiratory infection and VTE. There should be less distinction between venous and arterial events in decisions about preventing or aborting infections, especially in high-risk patients.
Daily treatment with aspirin for longer than 5 years reduces the long-term risk of colorectal cancer. A number of studies have suggested that long-term aspirin use may reduce the risk of several ...noncolorectal solid cancers, but clear evidence for a preventive effect is lacking.This study investigated the possible effect of aspirin on reducing the risk of fatal cancer among patients with gastrointestinal and nongastrointestinal cancers. Data were obtained from randomized trials with aspirin, originally conducted on prevention of vascular events. Eligible trials with median duration of scheduled trial treatment of at least 4 years were identified in the medical literature.Pooled results comparing the effect of aspirin and controls on deaths due to cancer showed 674 deaths due to cancer among 25,570 patients; aspirin significantly reduced the risk of cancer deaths (odds ratio, 0.79; 95% confidence interval CI, 0.68–0.92; P = 0.003). Analysis of data on time of death available from 7 trials (23,535 patients, 657 cancer deaths) showed that a reduction in risk of death was apparent only after 5 yearsʼ follow-up for all cancers (hazard ratio HR, 0.66; 95% CI, 0.50–0.87) and gastrointestinal cancers (HR, 0.46; 0.27–0.77; P values for both = 0.003). Three posttrial follow-up studies on the 20-year risk of death due to cancer (1634 deaths in 12,659 patients) showed that the reduction in risk by aspirin treatment compared with controls remained lower for all solid cancers (HR, 0.80; 95% CI, 0.72–0.88; P < 0.0001) and gastrointestinal cancer (HR, 0.65; 95% CI, 0.54–0.78; P < 0.0001). The greatest benefit was found with scheduled duration of trial treatment of ≥7.5 years for solid cancers (P = 0.003) and gastrointestinal cancers (P = 0.0001). Reductions in risk of death due to esophageal, pancreatic, brain, and lung cancer were evident only after a latent period of 5 years, whereas reductions in deaths due to stomach, colorectal, and prostate cancer were not observed until about 10 years. The benefit on the 20-year risk of death was limited to certain cancers, especially adenocarcinomas of lung (P = 0.04) and esophagus (P = 0.0001). The absolute reduction in risk of death due to cancer at 20 years increased with age, reaching 7.08% (95% CI, 2.42–11.74) at age 65 years or more. No increased benefit was found for aspirin doses greater than 75 mg daily and the effect was unrelated to gender or smoking.These findings provide evidence that daily aspirin reduces the risk of death due to several common noncolorectal cancers during and after the trials, with consistent effects across different populations and benefit increasing with duration of treatment.
Objective To assess the effect of combined hormone replacement therapy (HRT) on health related quality of life.Design Randomised placebo controlled double blind trial.Setting General practices in ...United Kingdom (384), Australia (94), and New Zealand (24).Participants Postmenopausal women aged 50-69 at randomisation; 3721 women with a uterus were randomised to combined oestrogen and progestogen (n=1862) or placebo (n=1859). Data on health related quality of life at one year were available from 1043 and 1087 women, respectively.Interventions Conjugated equine oestrogen 0.625 mg plus medroxyprogesterone acetate 2.5/5.0 mg or matched placebo orally daily for one year.Main outcome measures Health related quality of life and psychological wellbeing as measured by the women’s health questionnaire. Changes in emotional and physical menopausal symptoms as measured by a symptoms questionnaire and depression by the Centre for Epidemiological Studies depression scale (CES-D). Overall health related quality of life and overall quality of life as measured by the European quality of life instrument (EuroQol) and visual analogue scale, respectively.Results After one year small but significant improvements were observed in three of nine components of the women’s health questionnaire for those taking combined HRT compared with those taking placebo: vasomotor symptoms (P<0.001), sexual functioning (P<0.001), and sleep problems (P<0.001). Significantly fewer women in the combined HRT group reported hot flushes (P<0.001), night sweats (P<0.001), aching joints and muscles (P=0.001), insomnia (P<0.001), and vaginal dryness (P<0.001) than in the placebo group, but greater proportions reported breast tenderness (P<0.001) or vaginal discharge (P<0.001). Hot flushes were experienced in the combined HRT and placebo groups by 30% and 29% at trial entry and 9% and 25% at one year, respectively. No significant differences in other menopausal symptoms, depression, or overall quality of life were observed at one year.Conclusions Combined HRT started many years after the menopause can improve health related quality of life.Trial registration ISRCTN 63718836.
The added value of incorporating information from repeated blood pressure and cholesterol measurements to predict cardiovascular disease (CVD) risk has not been rigorously assessed. We used data on ...191,445 adults from the Emerging Risk Factors Collaboration (38 cohorts from 17 countries with data encompassing 1962-2014) with more than 1 million measurements of systolic blood pressure, total cholesterol, and high-density lipoprotein cholesterol. Over a median 12 years of follow-up, 21,170 CVD events occurred. Risk prediction models using cumulative mean values of repeated measurements and summary measures from longitudinal modeling of the repeated measurements were compared with models using measurements from a single time point. Risk discrimination (C-index) and net reclassification were calculated, and changes in C-indices were meta-analyzed across studies. Compared with the single-time-point model, the cumulative means and longitudinal models increased the C-index by 0.0040 (95% confidence interval (CI): 0.0023, 0.0057) and 0.0023 (95% CI: 0.0005, 0.0042), respectively. Reclassification was also improved in both models; compared with the single-time-point model, overall net reclassification improvements were 0.0369 (95% CI: 0.0303, 0.0436) for the cumulative-means model and 0.0177 (95% CI: 0.0110, 0.0243) for the longitudinal model. In conclusion, incorporating repeated measurements of blood pressure and cholesterol into CVD risk prediction models slightly improves risk prediction.
Objective To assess the long term risks and benefits of hormone replacement therapy (combined hormone therapy versus placebo, and oestrogen alone versus combined hormone therapy). Design Multicentre, ...randomised, placebo controlled, double blind trial. Setting General practices in UK (384), Australia (91), and New Zealand (24). Participants Postmenopausal women aged 50-69 years at randomisation. At early closure of the trial, 56 583 had been screened, 8980 entered run-in, and 5692 (26% of target of 22 300) started treatment. Interventions Oestrogen only therapy (conjugated equine oestrogens 0.625 mg orally daily) or combined hormone therapy (conjugated equine oestrogens plus medroxyprogesterone acetate 2.5/5.0 mg orally daily). Ten years of treatment planned. Main outcome measures Primary outcomes: major cardiovascular disease, osteoporotic fractures, and breast cancer. Secondary outcomes: other cancers, death from all causes, venous thromboembolism, cerebrovascular disease, dementia, and quality of life. Results The trial was prematurely closed during recruitment, after a median follow-up of 11.9 months (interquartile range 7.1-19.6, total 6498 women years) in those enrolled, after the publication of early results from the women's health initiative study. The mean age of randomised women was 62.8 (SD 4.8) years. When combined hormone therapy (n=2196) was compared with placebo (n=2189), there was a significant increase in the number of major cardiovascular events (7 v 0, P=0.016) and venous thromboembolisms (22 v 3, hazard ratio 7.36 (95% CI 2.20 to 24.60)). There were no statistically significant differences in numbers of breast or other cancers (22 v 25, hazard ratio 0.88 (0.49 to 1.56)), cerebrovascular events (14 v 19, 0.73 (0.37 to 1.46)), fractures (40 v 58, 0.69 (0.46 to 1.03)), and overall deaths (8 v 5, 1.60 (0.52 to 4.89)). Comparison of combined hormone therapy (n=815) versus oestrogen therapy (n=826) outcomes revealed no significant differences. Conclusions Hormone replacement therapy increases cardiovascular and thromboembolic risk when started many years after the menopause. The results are consistent with the findings of the women's health initiative study and secondary prevention studies. Research is needed to assess the long term risks and benefits of starting hormone replacement therapy near the menopause, when the effect may be different. Trial registration Current Controlled Trials ISRCTN 63718836
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