Well, if you're one of the people who gets to live an extra 30 years because your colorectal cancer didn't kill you, i'd say that's a pretty damn big difference.
I wonder if this may be related to Aspirin's effect on inflammation.
Long term inflammation is supposed to be "bad thing". Taking low doses of Aspirin for long time may help with silent inflammations throughout the body.
This should be testable by comparing effects of Aspirin with other anti-inflammatory drugs (taken in similar regime).
I don't think so, low dose aspirin has little effect on inflammation.
Aspirin (ASA)is special WRT NSAID, in that it inhibits the Cyclo-oxygenase (COX) enzymes irreversibly.
COX are a family of enzymes that transform arachidonic acid to various inflamatory mediators called the prostaoids (comprising prostaglandins, prostacyclin and thromboxanes). There are two subtypes, present in different tissues, but since ASA inhibits both kinds.
Platelets contain COX and uses it produce Thromoxane A2, a potent vasoconstrictor and platelet activator. Since platelets don't have a nucleus, the effect inhibitory effect is permanent in them. New platelets have to be produced in order to restore a normal clotting activity. Since the platelet have an half life of more than a week, the effect is long lasting.
Other cells can synthesize COX as needed. Low dose aspirin has thus little effect on them. You need a much higher dose to get a clinically noticeable anti-inflamatory response.
In blood vessels, activated platelets use COX to synthesize Thromoxane A2 (TXA). TXA further promotes vasoconstriction, platelet activation and aggregation, leading to the formation of a blood clot [1].
On the other hand, endothelial cells (the inner layer of blood vessels) use COX to synthesize a prostaglandin (PGI2), which antagonizes TXA (vasodilatation, platelet inhibition).
ASA disrupts the TXA2/PGI2 equilibrium in favor of PGI2, inhibiting platelet activation.
Other NSAID also have an anti-aggregation activity, but it is far more short lived, and requires anti-inflammatory doses to do so.
That said, I can't prove that a chronic, subclinical anti-inflammatory effect isn't at play here too.
EDIT:
A Google scholar search confirms that TXA2 is involved in carcinogenesis [2-3].
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[1] Such a clot is fragile. It is then stabilized by the coagulation process: the irreversible binding of fibrinogen into a fibrine mesh.
That's what I was thinking when I read this. I'd bet you would get even more benefit from taking a low dose of hemp oil, because not only is that a stronger (and less toxic) anti-inflammatory, but it's also anti-angiogenic. In any event though total morbidity is much more interesting than cancer risk.
Interesting finding, but I wonder: did they allow those patients to opt-in to the aspirin regimen?
If so, it could potentially be related to other confounding variables -- eating healthier or avoiding certain chemicals or some such. Basically, allowing opt-ins suggests that people who do so could already be more vigilant about their health.
If not, given the previous indication of benefits from an aspirin regimen, I wonder if there was an ethical concern in not giving it to all patients.
I took 100 milligrams a day for prophylactic purposes for about 5 years. It caused severe gastritis, to the extent that I had to go to hospital last year. Since having to discontinue taking it for a medical procedure, I discovered that my stomach is much better and have never taken a single pill since.
Thanks for the link. Nice quote: "In fact, if you believe what you read in the scientific literature, you shouldn’t believe what you read in the scientific literature."
I think we can do better than "a good reason to not pop it like mints".
Aspirin Myocardial Infarction Study
"Doses of 1,000 mg per day of aspirin caused gastrointestinal symptoms and bleeding that, in some cases, were clinically significant. In the largest postinfarction study (the Aspirin Myocardial Infarction Study (AMIS) with 4,500 people), the percentage of incidences of gastrointestinal symptoms for the aspirin (1,000 mg of a standard, solid-tablet formulation) and placebo-treated subjects, respectively, were stomach pain (14.5%, 4.4%), heartburn (11.9%, 4.8%), nausea and/or vomiting (7.6%, 2.1%), hospitalization for GI disorder (4.9%, 3.5%). In the A.I. and other trials, aspirin-treated patients had increased rates of gross gastrointestinal bleeding. Symptoms and signs of gastrointestinal irritation were not significantly increased in subjects treated for unstable angina with buffered aspirin in solution. "
So for men the lifetime risk of dying from some kind of cancer goes from about 23% to around 19% based on the 21% reduction in overall cancer deaths found in the study.
Specfically for 'death due to gastrointestinal cancers' dropping 54%. Assuming that statistic would be paired with the chance of death from stomach cancer at the above site, happy to be corrected if more of the cancers described there should be included. However if is just that then your chance of dying from that specific cancer goes from 0.53% to about 0.25%.
Your tone is a bit suspect (what is not "real" about aspirin after all) but I liked your link. Especially "Physical inactivity: People who are physically active are at lower risk of developing colorectal cancer."
It's a single isolated new study while the prevention on Wikipedia's article is amply supported and accepted. And instead of taking aspirins a healthier lifestyle will help with many other problems.
There are many side effects to taking aspirin regularly, even for a low dose. Gastrointestinal ulcers, blood acidity (calcium withdrawn from bones to compensate), and all the coagulation issues.
It's annoying high profile studies promoting quick fixes with a pill get all the attention while more important work is ignored. A healthy lifestyle can't be replaced with snake oil.
Unfortunately, that means we hackers with desk jobs had better be taking our aspirin (or getting a lot of colorectal activity, I suppose--refuse the scanner next time you fly).
It is still quite significant, but it does not actually prevent the cancers, just reduces their fatality rate.