Artikel
Aspirin use and breast cancer risk – a meta analysis and meta regression of epidemiological studies from 2001 to 2005
Suche in Medline nach
Autoren
Veröffentlicht: | 6. September 2007 |
---|
Gliederung
Text
Background: Recent meta-analysis suggest that aspirin may reduce breast cancer risk, but failed to examine reasons for heterogeneity and to investigate a dose response relationship. Referring to this, our meta-analysis aimed to complete the current research.
Methods: We systematically searched for cohort studies and case-control studies in Medline, Cancerlit and Embase from 2001 to 2004, which evaluated the association between aspirin and breast cancer risk and reported a relative risk or odds ratio including confidence intervals or information to permit their calculation. We calculated a pooled estimate for the RR and investigated reasons for heterogeneity between the individual studies and analysed a dose response relationship considering frequency and duration of use using random effect models.
Results: We identified 10 studies (4 cohort studies and 6 case-control-studies) which met the inclusion criteria. The combined estimate of the RR was 0.75 (95 % CI=0.65-0.87) using the random effects model. Heterogeneity between the studies could not be explained by the covariates study type and study population. The combination of frequency and duration of aspirin use resulted in a significant dose-response-relationship between aspirin use and breast cancer risk. Each additional pillyear reduced the breast cancer risk about 7 %.
Conclusion: Our meta-analysis supports the current evidence, that aspirin may reduce breast cancer risk. Results dos not vary among different study types. Moreover, a dose-response-relationship seems to exist. However, results have to be interpreted carefully, as exposure categories were defined very heterogeneously among the studies which weakens the validity of the pooled estimates.