Meta-analysis on the association between nonsteroidal anti-inflammatory drug use and lung cancer risk.

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs), especially aspirin, have emerged as the most potential chemopreventive agents. However, epidemiologic studies reported a controversial association between NSAID use and lung cancer risk. We conducted a meta-analysis to summarize the evidence for such relationship.
METHODS: Eligible studies were identified by searching the electronic literature PubMed, Medline, Embase, and ScienceDirect databases for relevant reports and bibliographies. Studies were included if they designed as cohort study, case-control study, or clinical trial on the NSAID exposure and lung cancer with sufficient raw data to analyzes. Relative risk (RR) or odds ratio (OR) was used to evaluate the association between NSAIDs and lung cancer. Stratified analysis was also performed.
RESULTS: A total of 19 studies including 20,266 lung cancer cases met the inclusion criteria. To the effect of aspirin on lung cancer, the combined RR for cohort studies was 0.96 (95%confidence interval [CI]: 0.78-1.19) and OR for case-control studies was 0.87 (95%CI: 0.69-1.09). When restricted in exposure of aspirin use to 7 tablets per week, the OR was 0.80 (95%CI: 0.67-0.95). The summary risk estimates showed no significant association between non-aspirin NSAID or overall NSAID use and lung cancer risk.
CONCLUSIONS: Aspirin use with a dose of 7 tablets per week can significantly reduce lung cancer risk, whereas non-aspirin NSAIDs showed no chemopreventive value. Greater attention should be paid to identifying appropriate individuals for this new indication of aspirin and the optimal dose and duration as a chemopreventive agent.