[Aspirin against cancer]

[What is the place of aspirin in venous thrombosis prophylaxis?]

Since Virchow triade, it is well established that venous thrombosis is a multifactorial process involving various cellular and plasmatic protagonists. Aspirin antihrombotic efficacy seems not only due to its antiplatelet effects and thromboxane A2 synthesis inhibition. Anti-Platelet Trialists Collaboration metaanalysis stressed in 1994 the interest of aspirin treatment leading to 40% reduction of thrombosis relative risk. Regarding studies heterogeneity and outcomes criteria variety, its use in such context remains a matter of debate. Is the recent publication of PEP trial showing a significant decrease of pulmonary embolism mortality (0.6 versus 0.3%, p = 0.03) able to reinforce aspirin use in venous thrombosis prophylaxis? Were numerous and consecutive criticisms justified? Is there still a potential indication for aspirin in this setting? The experts of the last ACCP consensus conference recommended not to recommend aspirin in venous thrombosis prophylaxis with the highest level of evidence (grade A).

[Pharmacology of aspirin]

Aspirin (acetylsalicylic acid) is the best-known salicylate and belongs to the non steroid anti-inflammatory drug class. Despite wide use being made since more than 100 years, knowledge about mechanism of action and therapeutic issues continually evolves. The main mechanism of action is prostaglandin synthesis inhibition. This is achieved through inhibition of prostaglandin endoperoxide synthase (PGHS) or cyclooxygenase (COX) synthesis. Most of the therapeutic uses of aspirin are explained by this mechanism. Nevertheless aspirin uses change as time goes by: if the main one during the first fifty years was an analgesic, anti-pyretic and anti-inflammatory one, the last fifty years saw aspirin being used mainly as an anti-thrombotic agent, in primary and secondary thrombo-embolic prevention. Better knowledge of mechanism of action points today at, on one hand, more selective and therefore better tolerated molecules, and, on the other hand, at new therapeutic applications, such as anti-cancer and neurodegenerative diseases prevention.