Wednesday, January 18, 2017

#9 Screen for Everything! Every Day!

Welcome to my new blog! After much internecine struggle, the staff at Dr Tumoriffic's Inappropriate Guide got fed up with staff at and left in a huff. On the way out the door, they copied all of the old posts and they built this new blog.

(Most of the above is a complete lie. I have no staff for either blog. I started this one because it made sense to put the advice posts in a different place than the updates on my own health. Hopefully, it will be a long time before I have to write one of those.)

Dear Dr. Tumorific, 

Why can't I be screened for all cancers?


Dear Z,

You can! Get every lab test anyone ever heard of and more! Get a head-to-toe CT (a.k.a CAT) scan! Get more mammographies that you have boobs! Have an entire gastroenterology department climb down your throat and up your colon! Get ultrasounds in all your most awkward places! And do all of them all over again every year! *

These and more are available if you have the bucks. For instance, do a quick Google of "executive physical" paired with the name of nearly any prominent medical center, and you can find a program on which the world's worried wealthy can blow big bucks. These come with all sorts of non-medical luxuries, so, if you want something less fancy but just as medically extravagant, find a functional medicine clinic! There, you will get all sorts of tests and all sorts of expensive remedies!

So, are miserly death panels and insurance companies withholding state-of-the-art prevention from the masses? Are in-the-know doctors sneaking off to exclusive clinics for a yearly inspection? Are you missing out? No. No. NO.

These testing programs are like buying a thousand lottery tickets where the second through hundredth prizes are pointless surgeries with possible complications, radiation-induced cancers, and a whole lot of uncomfortable tests and unnecessary anxiety. Worse, when you win first prize--an early, curable cancer--it may have been harmless in the first place. But you will never know for sure. The one thing you can be sure of is that your wallet will be a lot emptier.

"But Dr. Tumoriffic," you say, "isn't screening and prevention good all the time? Don't you want to know in advance and treat early?" Ah, now there's the rub. Not all tests are good screening tests, and not all screening tests are appropriate for all people.

What is screening?

To screen is to test a patient for a condition for which they have no signs or symptoms. For instance, a routine colonoscopy is a screening test. Doing the same test once there is a problem is not screening. So doing a colonoscopy to look for why a patient who has blood in their stool is a diagnostic test, not a screening test.

Problems with overscreening:

To understand why your doctor should not overscreen you, the first thing that you must admit is that you are abnormal. For instance, the definition of 'normal' for any single lab test is that 95% of patients tested have a value within the 'normal' range. That means that 5% of healthy patients will have a value that is 'abnormal.' If I do enough lab tests on you, it is all but inevitable that one of those tests will be abnormal.** Only occasionally will one of those 'abnormal'' tests have any importance at all.***

False Positives: Unfortunately, at the current state of medical technology, most of our tests are liable to ring alarm bells when their is nothing really wrong. What's important is the context. If I do a chest CT scan on a 3 pack-a-day smoker with weight loss who is coughing up blood and struggling to breath, whatever abnormality shows up in their lung is probably worth worrying about.

If I do a whole body CT on healthy 24-year-old with no history of bad habits, I can guarantee you that there will be something strange there. And the older the patient, the more of those strange things there will be.*** Very occasionally, there may be something meaningful. But the overwhelming majority of the time, I'll just scare the heck out of the patient. Very likely, I will expose the patient to unnecessary and potentially cancer-causing radiation following a meaningless abnormality with subsequent scans, and, sometimes the patient will have dangerous and useless surgery to evaluate what turns out to be nothing. And I will make my healthcare system lots of money

Overdiagnosis: This one is really thorny. As we have done more and more screening for cancer, we have discovered that not all cancers are created equal. For instance, an article in the October 13, 2016 issue of the New England Journal of Medicine noted that, after the advent of regular screening mammography, the incidence (number of cases detected per 100,000 patients) of large breast cancers (> 2cm) decreased by 30 per 100,000. That means that, presumably, in a group of 100,000 patients, those 30 cancers were detected and cured as small cancers. Sounds pretty good, right?

Yes and no. During the same period, the number of small (< 2cm) breast cancers increased by 162 per 100,000. If mammography were perfect, you would expect the increase to be 30 per hundred thousand. Instead, there are 132 extra cases of small breast cancer per 100,000. The most likely explanation is that those 132 cancers would disappear by themselves had those patients never had mammograms!

That is not to say that mammograms are useless. They may be accountable for the 2/3 of the substantial reduction in breast cancer mortality since testing began. (The other 1/3 comes from improved treatment.) On balance, mammograms may do more good than harm. But for every 30 large tumors avoided, there are still probably 132 out of 100,000 women who had breast surgery and sometimes worse even when they didn't need it. All of them and their doctors probably consider those surgeries lifesaving, but there may be no way to tell for sure. *****

The worst of both worlds: The prostate specific antigen (PSA) test is the most troubling of common cancer screening tests. There are 26,100 prostate cancer deaths per year in the United States. A good prostate cancer screening test would be a great thing. However, the test we have is very flawed.

On average, if I tested 1000 men for PSA levels, I would find about 150 whose PSAs were high. Of those, between 40 and 50 would actually have prostate cancer. Of those, I might or might not (the two leading studies disagree on this) prevent a single (!!!) death from prostate cancer. Meanwhile, by treating those 40 or 50 prostate cancers, I will have caused a lot of men to be forever impotent, forever incontinent, or both. I will also have caused other painful complications.

But how can this be? Why did 150 of those men have high PSAs? What happened to all those guys whom I didn't save?

  1. Most men with high PSAs do not have prostate cancer. They have benign prostatic hypertrophy. That is a nonmalignant enlargement of the prostate that eventually affects all men and may or may not raise the PSA.****** 
  2. Most prostate cancers grow so slowly, men with prostate cancer are much more likely to grow old and die of something else. Prostate cancer is incredibly common. Most of the time, though, it grows very very slowly. Autopsies of men over 55 who die of other causes show that 30% of them had prostate cancer. Autopsies of men over 80 show that 2/3 of them have prostate cancer.*******

Is the PSA a useless test? Far from it. The PSA is very useful in watching men who have had prostate cancer to see if they are having a recurrence. It also is useful in men at high risk for developing dangerous prostate cancer. Otherwise, I skip it.

Also, there are other tests which are completely useless, many of which are offered by various quacks. But that is a topic for another time.

So what should Tumoriffic readers take away from this? Medicine is always getting better, but it's not perfect. Doctors promising to screen for everything are likely more concerned with your money than your health.

Oh, boy. Next post should be something less complicated!

Be well,

Dr. Tumoriffic

* And cancer screening is just the beginning. You can get stress tests and coronary calcium CT scans for your heart, ultrasounds for your carotid arteries, and more!

** Thus, every single person who reads this blog is a weirdo in some way or other. Even if all your lab values are normal, that's weird too.

*** If you do an MRI scan of MY head and see something suspicious that is new, chances are pretty high that it's cancer. Even so, not always. (See and, more recently, the post starting with

**** Generally, a functional medicine doc will tell you these 'abnormal' tests are causing your back pain, your headaches, your dizziness, your fatigue, your angst, etc. with all sorts of useless nostrums that relieve you of nothing but your money. If you don't feel better, there must be more things wrong, and you win another round of testing and so on. If no remedies work, then you're doing it wrong, but the functional medicine doctor is never wrong. (See (And if you get better, chances are that had nothing to do with the 'treatment.' Minor problems tend to get better on their own. But that's fodder for a whole other post.)


****** I tell my male patients that the only things that grow for your entire life are your ears, your nose, your feet, and your prostate. If men live to be 200 years old, we'll all be walking around with basketballs between our legs.

******* All stats come from an UptoDate Prostate Cancer Screening article. Unfortunately, it's behind a paywall, so you can't have it!

The only kind of CAT scan everyone should get:

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