1438 - Low-dose aspirin and risk of gastric and oesophageal cancer: a population-based study

Background

Evidence suggests that low-dose aspirin is associated with a 30–40% protective effect against colorectal cancer (CRC) yet its effect on other gastrointestinal cancers has been less studied. We aimed to quantify the association between use of low-dose aspirin and risk of gastric/ oesophageal cancer using a population-based primary care database in the United Kingdom – The Health Improvement Network.

Methods

Among persons aged 40–89 years from 2005–2015, ∼200,000 new users of low-dose aspirin (75–300 mg/day) were each matched to a non-user by age, sex, time since study entry and number of primary care visits in the previous year. Individuals were followed (max. 18 years) to identify incident cases of gastric/oesophageal cancer. Nested case–control analyses were conducted using 5000 controls for both sets of cancer cases frequency matched by age, sex and calendar year. Adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for current vs. non-use of low-dose aspirin using logistic regression. Current use was when low-dose aspirin use lasted to 0–90 days before the index date (event date for cases, random date for controls) and total duration of use before the index date was >1 year; non-use was no use of low-dose aspirin ever before the index date or use that ended ≥1 year before the index date.

Results

We identified 727 incident cases of gastric cancer and 1394 incident cases of oesophageal cancer. As shown in the table, compared with non-use, current use of low-dose aspirin was associated with a significant 54% reduced risk of gastric cancer and a significant 41% reduced risk of oesophageal cancer. Protective effects were seen for both cancers irrespective of total previous duration of low-dose aspirin use.Table:

681PD Odds ratios (95% confidence intervals) for the association between use of low-dose aspirin (current vs non-use) and gastric/oesophageal cancer

Adjusted by age, sex and primary care practitioner visits in the year before the index date.

Conclusions

Our results indicate that use of low-dose aspirin is associated with a significantly reduced risk of gastric and oesophageal cancer as supported by mechanistic data.

Clinical trial identification

Editorial acknowledgement

Susan Bromley, EpiMed Communications Ltd (Oxford, UK).

Legal entity responsible for the study

Luis A Garcia Rodriguez.

Funding

Bayer AG.

Disclosure

L. Garcia Rodriguez: Honoraria (self), Research grant / Funding (institution), Travel / Accommodation / Expenses: Bayer AG. P. Vora: Full / Part-time employment: Bayer AG. M. Soriano-Gabarró: Full / Part-time employment: Bayer AG. L. Cea Soriano: Research grant / Funding (institution): Bayer AG.