August 23, 2005

BUT I JUST KNOW WE'RE BETTER OFF....:

Warned, but Worse Off (STEVEN WOLOSHIN, LISA SCHWARTZ and H. GILBERT WELCH, 8/22/05, NY Times)

[W]e just don't know if lung cancer screening does more good than harm. While the benefits of screening are unproven, the harms - one familiar, the other less so - are certain.

The familiar harm is caused by false alarms. CT scans are great at finding abnormal areas of the lung. But while relatively few people have lung cancer, many have other lung abnormalities. After a positive CT scan, many are biopsied, and most will turn out not to have cancer. A lung biopsy is not a trivial procedure. Although serious complications are rare, the procedure may result in hospitalization (largely for a collapsed lung), and there have been deaths.

The less familiar, but more worrisome, harm comes from overdiagnosis and overtreatment. In the largest study to date, Japanese researchers using CT scans found almost 10 times the amount of lung cancer they had detected in a similar group of patients using X-rays. Amazingly, with CT screening, almost as many nonsmokers were found to have lung cancer as smokers.

Given that smokers are 15 times as likely to die from lung cancer, the CT scans had to be finding abnormalities that were technically cancer (based on their microscopic appearance), but that did not behave in the way most people think of cancer behaving - as a progressive disease that ultimately kills. So here's the problem. Because we can't distinguish a progressive cancer from a nonprogressive cancer on the CT scan, we tend to treat everybody who tests positive. Obviously, the patients with indolent cancers cannot benefit from treatment; they can only experience its side effects. Treatment - usually surgery, but sometimes chemotherapy or radiation therapy - is painful and risky. Some 5 percent of patients older than 65 die following partial lung removal, and nearly 14 percent die with complete removal.

But wait a minute. Don't those compelling five-year survival statistics of 80 percent vs. 15 percent prove that CT screening works? The short answer is no. You have to consider exactly how a five-year survival rate is figured. It is a fraction. Imagine 1,000 people diagnosed with lung cancer five years ago. If 150 are alive today, the five year survival is 150/1000, or 15 percent. Yet even if CT screening raised the five-year survival rate to 80 percent, it is entirely possible that no one gets an extra day of life.


Dr. Welch is a hero.

Posted by Orrin Judd at August 23, 2005 12:00 AM
Comments

Rather than trust statistics and those who explicate them, I'll go for the tests hoping that should some anomaly be found, it may be caught while it's still treatable. If this is na´ve and jejune, so be it.

Posted by: erp at August 22, 2005 3:08 PM

erp: Um, did you even read the article?

Posted by: b at August 22, 2005 3:12 PM

As b points out, you don't necessarily want "it" found precisely because they'll treat it.

Posted by: oj at August 22, 2005 3:14 PM

Don't get your cholesterol checked, either.

Posted by: carter at August 22, 2005 4:28 PM

Actually, I did read the article and assumed it was a spoof, but was too polite to say so in case I was wrong and they are merely crazy.

Posted by: erp at August 22, 2005 5:59 PM

erp:

The Wife works with them and not only are they not crazy but their work is brilliant.

Posted by: oj at August 22, 2005 6:04 PM

"Because we can't distinguish a progressive cancer from a nonprogressive cancer on the CT scan, we tend to treat everybody who tests positive. Obviously, the patients with indolent cancers cannot benefit from treatment; they can only experience its side effects."

In other words, that old surgeon's motto ("when in doubt, cut it out") hasn't changed in the last few decades, despite all the changes in how problems are detected.

Posted by: Raoul Ortega at August 22, 2005 6:36 PM

Sorry for being flippant.

This is a highly disturbing. Obviously, Dr. Mrs. Judd knows more by quantum leaps about medicine than I, however, this means changing everything. The entire thrust of modern medicine has been prevention, which made a lot more sense to me than seeing a physician only after symptoms have appeared.

I've read that lung cancer is so deadly because it's usually not the first place that cancer has struck so by the time it gets to the lungs a lot of damage has already been done. Quite a few friends and relatives, interestingly all men, have succumbed to lung cancer at about age 70.

How is one to manage their family's health with this new point of view. No tests at all? Are we to stop pap smears, mammograms? My husband takes half a dozen meds to lower cholesterol and blood pressure and diuretics, etc. These levels are periodically tested and his meds adjusted accordingly. Actually he's a poster child for the over weight under exercised retired male.

We're both scheduled for annual checkups in the next two weeks. Should we change our strategy?

Posted by: erp at August 22, 2005 7:04 PM

erp -

If the hubby is interested in disease prevention he should lose some weight and get some exercise - it would go a lot further towards prevention than seeing the doctor.

I thought all this was well known - we have known for at least 5 years that regular mammograms do not increase the likelihood of breast cancer detection. Our bodies have a good method of letting us know when some thing is really wrong - pain.

Posted by: Shelton at August 22, 2005 7:14 PM

Raoul:

The changes in detection only give them more opportunity to cut.

Posted by: oj at August 22, 2005 7:17 PM

erp:

Exercising and dropping some weight matter more--especially as a lifetime strategy, than frequent testing.

Posted by: oj at August 22, 2005 7:19 PM

Of course, but his capacity for self delusion is even larger than his waist line.

Posted by: erp at August 22, 2005 8:05 PM

Get lung caner and die, it's that simple. If that growth is malignant and progressive it dosn't matter if they got it early or not 99% of the time, it's very presence means it's already spread.

But if it's a false positive, which apparently happens alot with CT scans, they'll butcher you like a hog trying to cut it out, and maybe cripple or kill you. Therefor your odds are better just not getting tested, grim though that sounds.

That, I think, is the gyst of this article, though I could be wrong.

Posted by: Amos at August 22, 2005 9:26 PM

OK, here's the deal...
First of all, consider the bigger point of screening tests. First, they're supposed to be designed as a relatively easy test to apply to a general population to screen for a disease that's either A: relatively common (think hypertension, elevated cholesterol), or B: particularly nasty (think cancers). Second, to be a good screening test, they have to have good testing characteristics which basically translated, means a low rate of false positive results and a low rate of false negatives (and this is hard to do). Third, you need to show that there is some meaningful end-point to screening a general population and presumably treating the folks who have been found to have disease. So, for example, it's worthwhile to screen for hypertension because it's pretty clear that longstanding hypertension is associated with increased risk of heart attack, stroke, etc and furthermore, decreasing blood pressure is associated with decreases in risk. Cancer screening is a very different situation. These guys are saying a few things. One is that catching a cancer earlier does not necessarily change the ultimate endpoint, mortality, due to things like lead-time bias associated with earlier diagnosis. Another issue is that not all cancers behave the same in all people - a small focus of cancer cells may continue to grow and spread, they may have already spread even though the focus was already small, they may grow at a very slow rate, not spread and never cause you a problem or they may even regress. So, while it's entirely possible that in an individual person you may catch an early cancer that was going to spread if you didn't whack it out, this just has not been demonstrated in larger population studies. Finding a cancer earlier does not necessarily translate to increased survival and better quality of life. Furthermore, treating a cancer unnecessarily CAN cause signficant disease and angst. Personally, I don't want a hunk of lung whacked out (or any other body part) if it didn't need to be. Gil Welch et al are not advocating no screening - they're advocating knowing what you're getting yourself into, knowing the limitations of the test and knowing that you may not be changing your ultimate endpoint.

Posted by: The Wife at August 23, 2005 8:48 AM

The Wife: All well and good, but it's a little late for a lot of us to go to medical school to learn "what you're getting yourself into, .... " I've already been advised by a couple of people that I do too much research and bring more information than I need to medical discussions. Of course, these are people I no longer see, but nevertheless, my concern is that I don't have the information needed to make informed decisions.

That's why I'd like my physician to advise me on my best choices, not lay them all out and ask me to pick the ones I like best.

Posted by: erp at August 23, 2005 11:58 AM

erp: My brother in law's father just died. He had a lung abnomality, and foolishly chose to have it removed, even though he was fine. Everyone told him to let it be, but no...he's dead now. You may want to rethink that test.

Posted by: Xiaoding at August 23, 2005 2:37 PM
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