Atrial fibrillation General Medicine

Warfarin as a life-saver…

In cancer treatment, detection of a tumor in an early stage markedly increases the chance of favorable outcomes.  

Can the much-maligned blood thinner, warfarin, occasionally help in early detection of cancer?

Few pharmacologic agents receive more bad press than warfarin.  Stories, which are too numerous to count, like “Did warfarin kill my father,” can be widely found on internet forums, search engines, and are often quoted by reluctant patients–whose numerator of bad warfarin experiences is one.

It is true that warfarin has a narrow therapeutic window–a small difference between an effective dose and dangerous dose.


Here is the story of two recent patients I have seen who may have had their life saved by the blood-thinning effect of warfarin.  Both were older patients taking warfarin for stroke prevention: one had some minor GI bleeding and the other some GYN-type bleeding. Upon evaluation of both patient’s bleeding episodes, an early-stage malignancy was found.  Each have undergone appropriate treatment and both told me their cancer had not spread.   Although there will never be proof that warfarin prevents cancer–as it doesn’t–this is not the first time I have seen a malignancy discovered, perhaps at an earlier stage because of warfarin-induced bleeding.

No, I am not saying that warfarin should be used for the purpose of early stage cancer prevention, but rather, this may be an occasional “favorable” side effect of its blood thinning properties.

Paradoxically, in these two cases, a seemingly unfavorable effect (bleeding) turned out to be a positive.

Without dismissing the importance of bleeding issues with warfarin, I try and convince most patients that bleeding is statistically far better than stroke.  And the science of warfarin’s efficacy in appropriately selected patients is incontrovertible.

Be informed.



Anecdotes do not always make for sound medical practice.  

Warfarin is a highly effective agent for stroke prevention in appropriately selected patients.  Its efficacy requires the maximal amount of time in the therapeutic range of INR (International Normalized Ratio).  The INR measures the degree of blood-thinning effects.  If the blood is too thin (high INR) there is an enhanced risk of bleeding, and if the blood is too thick (INR<2.0), there is no benefit.  Maximizing the time in therapeutic range requires a motivated, well-educated patient along with skillful monitoring. A well-informed doctor is the best person to provide counseling on the risk-benefit ratio of any medical therapy.

6 replies on “Warfarin as a life-saver…”

I, too, have seen early cancer detection and cure as a result of Coumadin. Thanks for bringing this to light.

The most notable benefit of Coumadin, of course, is stroke prevention. It's unfortunately impossible to prove to anyone that all the effort and problems that go into taking Coumadin have actually done any good.

I don't think I've ever gotten so much as a "pat on the back" from a patient for preventing a stroke with Coumadin. On the other hand, if I had a dollar for every time I was hassled about prescribing this drug, I could probably retire today. Sometimes I envy the oncologists. Everybody accepts how evil their drugs are.

It's going to get really interesting when direct thrombin inhibitors are approved in the near future. You know that they'll be ungodly expensive and promoted so heavily, it will make the Multaq roll-out look like child's play. Hold your breath, it's going to be a bumpy ride.


Great points, Jay.

The direct thrombin inhibitor tug-of-war will be a window onto the the new health-care paradigm. Here, we will have more than a warfarin substitute; a drug superior in both its efficacy (stroke prevention) and safety (lower bleeding risk), but yet it will cost much more. Four dollars per month for warfarin, and many hundreds for the new direct thrombin inhibitor du jour.

Will the government, or insurers pay oodles more for the superior new drug? Will the NNT (numbers needed to treat) justify the added drug expense? Will the huge numbers of previously hesitant warfarin patients now become less reluctant when faced with 400/month versus warfarin's 4/month price tag?

"You pay…No, you pay…No you pay," and so on…

Who will pay; surely the government cannot pay for everyone to get first -line treatments. Not to pick on only the VA, but it was only a few years ago, when I recall that veterans were unable to get clinically proven, but yet to reach generic status drugs like, carvedilol and plavix.

We shall see.


It's also very effective for those with Factor V Leiden and allows me to continue with my passions – running and biking.

No doubt about it, I’m confident that warfarin has been a friend of mine preventing a possible stroke during an AF event not to mention that warfarin smoked out bladder stone that led to the detection of a very enlarged prostate. Dr John M there’s no telling how many times you may have saved me when you put me on warfarin. Thanks a lot! Santa Walt

I have mixed feelings about coumadin, like many people . My dad took it for years, first after having a heart valve replaced with a pig valve, and then 10 years later when the pig valve was replaced with a mechanical valve. There is no doubt in my mind that coumadin, in tandem with heart surgeries, not only saved his life but allowed him to live much longer than he would have otherwise. And perhaps it also prevented a stroke.

And yet Dad died about two weeks after slipping off a kitchen chair (he was tying his shoes) and banging his head on the floor. He had a lump there, but after the initial impact, it didn't hurt him. Mom tried to get him to go to the ER and have it checked, but he refused, saying he was just fine. The following day he had a bad headache. Continued doing all the things he normally did — he was a very active 77-year-old — but as time passed, the headache got worse. Finally — three nights after the injury — his pain became so severe that he let Mom take him to the hospital. It turned out he had a bleed between the skull and the lining of the brain, and the pooled blood was pressing on his brain.

Had he not been on coumadin, chances are that bleed wouldn't have happened. And perhaps if he'd gone to the ER immediately after bumping his head, they might have caught that bleed before it became so large. We'll never really know. Dad died in the hospital about 10 days later. By that time, he'd lost a great deal of his motor and cognitive skills; had he lived, he would have been helpless, and I know (he and Mom had both made it clear, long before) that he would not have wanted to live that way.

What can you say? Dad probably would have died much younger without his heart surgeries and coumadin, and I'm so grateful that we got to have so many wonderful years with him. And yet, I am so sad we lost him because of a simple bump on the head.


I am sorry to hear your Dad's story. Life balances on such a narrow precipice.

It is good that he got to experience the extra years, though.

And many thanks to you for sharing such a moving story.


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