Monday, December 13, 2010


Last week I forgot to post the article from Lancet 7th on aspirin and cancer deaths.
We all know well that aspirin was first discovered in the 17 century as a pain killer and also an anti-pyretic ( reduces fever ). It was the drug of choice for reduction of fever and joint pains in kids suffering from acute rheumatic fever. Later, in the 19th century, we learn that low dose aspirin ( half the pain killing dose ) reduces the incidence of heart attacks and heart attacks related deaths in those would were at high risk of heart attacks. Later, we found that this was also true for strokes. That low dose aspirin was a very effective anti-atherothrombotic agent. Of course now we have many more potent anti-atherothrombotic agents, like ticlopidine, clopidogrel, prasugrel, ticagrelol, and I am sure many more to come. We also know that low dose aspirin reduces stroke rates in people with low risk atrial fibrillation.
Now in a 7th Dec article in Lancet, we learn that low dose aspirin may confer a protective effect from cancer deaths, especially cancer of the colon. In a long term study, 4-8 years with follow-up till 20 years, aspirin was shown by the Oxford Research group, to reduce cancer deaths by 20-25%. We are talking about 100-75mg of aspirin daily ( the pain killing dose is nearer 325 mg or more. With cancer of the colon, the death rates can be reduced by up to 40%. I must say that this is very good. Actually, we suspected this all along, since the new millenium when we found that COX 2 inhibitors could reduce cancer rates in patients with polyposis coli. It looks like all anti-inflammatories may have this common benefit, and aspirin is probably the best studied and the best of the lot.
The why is more difficult to understand, probably because there are so many mechanisms for the formation of cancers. The most popular theories ( and it remains much a theory ), remains that aspirin is able to reduce mutation of the cells to form cancer cells. They also have some properties of improving program cell deaths ( apoptosis ) so that old cells will die on time and naturally. There is some suggestion that aspirin also lessens neo-vascularisation and vasculogenesis. All these remain theories that researchers are still working on. They probably all have some truths with some cancers, but probably not with all cancers.
Say what you may, it is very appealing that perhaps all middle age men ( the data on females are scarce ), should take 75 mg of aspirin a day. However, this is not without its risk.
The biggest risk with aspirin therapy is gastro-toxicity. Aspirin is acidic and can irritate the stomach. Gastric pain is perhaps bearable, but gastric bleeding can be life threatening. The average middle age men has an 0.1% chance of a gastric bleed, and some one on low dose aspirin has double that risk ( about 0.2% risk of bleed ).
That means that before you go out and buy low dose aspirin to take, you should consult your own doctor. That is also why we cannot lobby the government to add aspirin to drinking water. Gastric bleed is life threatening, but cerebral hemorrhage ( another potential risk with aspirin ), can be life threatening and very incapacitating.
So although aspirin is a very good friend, it can also be e very bad enemy. Be careful.
All things said and done, aspirin has proven to be a marvellous molecule, certainly a good candidate for the award of " molecule of the century ), if ever that is such an award.

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