

Daily Aspirin Linked to Steep Drop in Cancer Risk - aneth
http://www.businessweek.com/lifestyle/content/healthday/647054.html

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bd
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).

~~~
pygy_
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].

\--

[1] Such a clot is fragile. It is then stabilized by the coagulation process:
the irreversible binding of fibrinogen into a fibrine mesh.

[2]
[http://scholar.google.be/scholar?hl=nl&q=pgi2+neoplasm&#...](http://scholar.google.be/scholar?hl=nl&q=pgi2+neoplasm&btnG=Zoeken&lr=&as_ylo=&as_vis=1)

[3] [http://scholar.google.be/scholar?hl=nl&q=txa2+neoplasm&#...</a>

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rue
To be precise, it apparently cuts the risk of _death_ by 60% for colorectal
cancers, and 21% overall for cancers.

It is still quite significant, but it does not actually prevent the cancers,
just reduces their fatality rate.

~~~
swombat
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.

~~~
rue
I am not sure where I disagreed.

~~~
swombat
I don't think you disagreed either. Not sure why you got downvoted there... I
upvoted you back.

~~~
lkrubner
The downvoting on Hacker News has become erratic.

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c0riander
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.

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swombat
Is the statistical analysis behind this sound or does it suffer from the
problems outlined in
[http://www.sciencenews.org/view/feature/id/57091/title/Odds_...](http://www.sciencenews.org/view/feature/id/57091/title/Odds_Are,_Its_Wrong)

Also, are there any side-effects to eating an aspirin every day?

~~~
tickle_me_elmo
It can cause bleeding.

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melling
A low dosage of 75 milligrams is still a problem?

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pygy_
It's actually the dose used in cardiovascular prophylaxis to prevent
clotting...

You need a much higher dose to get an NSAID effect.

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wildmXranat
And on the other hand, it may and mostly does increase the chance of stomach
bleed. Isn't that the case and a good reason to not pop it like mints ?

~~~
aantix
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. "

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robinwarren
see the actual chance of dying from cancer here:
[http://www.cancer.org/Cancer/CancerBasics/lifetime-
probabili...](http://www.cancer.org/Cancer/CancerBasics/lifetime-probability-
of-developing-or-dying-from-cancer)

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%.

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ugh
Now if only Aspirin wasn’t so damn expensive in Germany (and other European
nations):
[http://andrewhammel.typepad.com/german_joys/2007/09/prescrip...](http://andrewhammel.typepad.com/german_joys/2007/09/prescription-
dr.html)

~~~
thibaut_barrere
In France, a box of 20x1g pills is around 3 euros, so you can get 1g per day
at 4.5€ per month (~0,15€ per day).

I find this rather cheap personally.

~~~
ugh
Most will be able to pay it but it is still obscenely expensive compared to
what you pay elsewhere for completely stupid reasons.

~~~
thibaut_barrere
I understand your point about the difference between places etc.

But locally, calling 4.5€ per month "obscenely expensive" is really far-
stretched. One baguette cost 1€ here (~ 30€ per month).

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alecco
How about real prevention:

<http://en.wikipedia.org/wiki/Colorectal_cancer#Risk_factors>

~~~
danteembermage
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."

~~~
khafra
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).

~~~
alecco
That's not necessarily true. Eat healthier, take a bike, run or walk on your
commute. With just that your chances improve significantly.

~~~
khafra
Sadly, exercise does not overcome the effects of prolonged sitting:
[http://www.sciencedaily.com/releases/2010/07/100722102039.ht...](http://www.sciencedaily.com/releases/2010/07/100722102039.htm)

