[Aspirin against cancer].

PURPOSE: That aspirin as an anti-aggregative and anti-inflammatory compound might prevent tumor spread is an old concept that is still not of clinical relevance. To date, aspirin has been shown in several epidemiologic studies to be linked with a reduction of colorectal cancer incidence, as well as the incidence of lung and breast cancer. In this issue, we have summarized the mechanisms that support this hypothesis, and we have analysed the main clinical studies.

RESULTS

Only case-control studies and most of the prospective cohort studies showed a reduction of colorectal cancer incidence in regular aspirin users. Nevertheless, the minimum effective doses of aspirin and the duration of therapy remain unclear. To date, only one prospective randomized trial has evaluated the influence of aspirin in the prevention of colorectal cancer. Despite the inclusion of 22,000 subjects and a five-year follow-up, aspirin failed to show any protection. The mechanism of the potential role of aspirin in preventing cancer, primarily supposed to rely on the antiprostaglandin effect, is now under debate. Few studies have evaluated the prevention of other cancers, such as breast or lung cancers, by aspirin. Data remain too sparse to allow any conclusion.

CONCLUSION

The role of aspirin in the prevention of colorectal cancer still needs further studies, such as a prospective randomized study, which should be conducted in a high-risk population.