Ye Xiaohua1, Yao Zhenjiang, Liu Weidong, Xun Pengcheng, Chen Sidong. 1. School of Public Health, Guangdong Key Laboratory of Molecular Epidemiology, Guangdong Pharmaceutical University, Guangzhou, China; School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China.
Abstract
BACKGROUND: The role of aspirin use in chemoprevention of esophageal adenocarcinoma (EAC) is still unclear. Previous meta-analyses have reported a beneficial effect of aspirin use, whereas it remains still under debate whether there are non-linear frequency-risk and duration-risk relations, such as a "threshold" effect. METHODS: Nine observational studies reporting the association between aspirin use and EAC risk were selected through a combined search with the PUBMED and EMBASE electronic databases of articles published before June 2013. Overall odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed-effects models, and the cubic spline regression models were performed for the study of frequency-risk and duration-risk relations. RESULTS: A monotonically decreasing relation was observed only for ≤ 4.5 times per week (OR=0.75, 95%CI 0.64-0.88, for twice per week; OR=0.59, 95%CI 0.45-0.78, for 4.5 times per week) and ≤ 6 years (OR=0.82, 95%CI 0.76-0.91, for 1 year; OR=0.53, 95%CI 0.37-0.75, for 3 years) of aspirin use using the non-users as the reference. Once the frequency is more than 4.5 times/week or the duration is longer than 6 years, no further benefit was observed. CONCLUSION: Our findings suggest that there may be non-linear threshold relations of frequency and duration of aspirin use with the risk of EAC. Further data from randomized clinical trials are required.
BACKGROUND: The role of aspirin use in chemoprevention of esophageal adenocarcinoma (EAC) is still unclear. Previous meta-analyses have reported a beneficial effect of aspirin use, whereas it remains still under debate whether there are non-linear frequency-risk and duration-risk relations, such as a "threshold" effect. METHODS: Nine observational studies reporting the association between aspirin use and EAC risk were selected through a combined search with the PUBMED and EMBASE electronic databases of articles published before June 2013. Overall odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using fixed-effects models, and the cubic spline regression models were performed for the study of frequency-risk and duration-risk relations. RESULTS: A monotonically decreasing relation was observed only for ≤ 4.5 times per week (OR=0.75, 95%CI 0.64-0.88, for twice per week; OR=0.59, 95%CI 0.45-0.78, for 4.5 times per week) and ≤ 6 years (OR=0.82, 95%CI 0.76-0.91, for 1 year; OR=0.53, 95%CI 0.37-0.75, for 3 years) of aspirin use using the non-users as the reference. Once the frequency is more than 4.5 times/week or the duration is longer than 6 years, no further benefit was observed. CONCLUSION: Our findings suggest that there may be non-linear threshold relations of frequency and duration of aspirin use with the risk of EAC. Further data from randomized clinical trials are required.