Our videos and the most recent newsletter explore various aspects of health screening, assessing the risks and benefits of tests such as mammograms, colonoscopies, PSA’s, stress tests, and even basic blood work. The idea of screening is to find problems before they become untreatable, such as mammograms discovering early breast cancer before it can spread or a heart stress test finding heart blockages before they lead to heart attacks. Virtually everything we do as medical providers can be construed as screening, from listening to your heart to checking vital signs to ordering blood tests. Screening occurs in the absence of symptoms. In other words, if you come to see us with chest pain or heart palpitations and we order heart tests, that’s not screening. Nor is it screening to check blood tests to monitor your medicines or because you are tired or don’t feel well. Screening constitutes the exam and testing we do in the absence of symptoms. You come to us feeling well, and we order a bunch of tests.
Does it work? If we thoroughly dig into your body and reveal a problem you didn’t know about, then try to fix that problem, will you live longer and better? Well, it’s complicated, kind of yes and know, which is not the absolutism that most people seek. Studies have shown that the more your life is medicalized—the more specialists you see and tests you get—the worse your outcome will be. In the Blue Zones, where health screening is anathema, people live the longest by staying away from doctors and simply adhering to healthy habits.
There are some screening tests that have been shown to save lives, but not to the extent that people are led to believe. Certainly, Pap smears in women under 65 can prevent cervical cancer death, but that is a rare lethal cancer and so it takes several thousand pap smears to save a life. Mammograms before age 75 too have been shown to be beneficial, but not miraculous. Although it is touted that there is a 20% reduction in breast cancer deaths among women who have regular mammograms, that number is somewhat deceptive. In fact, out of 1000 women who get regular mammograms, 4 will die of breast cancer, while out of 1000 women who never get mammograms, 5 will die of breast cancer. That is a 20% reduction, but it translates to 1/1000 lives saved, and almost as many women dying of breast cancer who get mammograms than those who don’t. The numbers are similar with colonoscopies.
And of course, all screening tests have complications. First there is stress: having an abnormal test can trigger fear and anxiety, and it can even impair someone’s life. Most abnormal tests are false positives, meaning that the test shows that something can be wrong but only with more testing and with time can we ascertain if it’s serious. That’s scary stuff, and some people don’t want to go through that. And too a positive test can lead us in several dangerous directions that cause more harm than good. For instance, many breast cancers are not lethal, they sit there or recede, but if we find a cancer we will treat it with aggressive therapies, meaning that you would not have died of the cancer but you may well die or be injured by the treatment. Also, the very tests needed to determine if your abnormal screening test is a false positive, such as biopsies and high radiation scans, can cause direct harm, even death. The worst thing is to have a doctor tell you: “I have good news and bad news. On the good side, we found you don’t have cancer. On the bad side, we popped your lung and you’ll need to have a tube in and get more testing.” I have seen many people get colonoscopies that popped their colons and caused severe harm and disability, even though the test was normal. And my grandfather died of the colonoscopy prep, which itself can cause damage to frail people.
And those are the screening tests that are helpful! We have several videos on our website to demonstrate this, and I recommend everyone watch our mammogram video that was made by Kaiser Health News and featured on NPR.
Then there are the litany of screening tests that save no lives and that cause harm. Virtually every aspect of the physical exam fits into this category, from listening to carotid arteries to sticking our fingers into the rectum. In fact, studies clearly indicate that apart from checking the heart rhythm and blood pressure periodically, every other part of the physical exam should be geared toward a patient’s symptoms, not done to find and fix things that don’t bother the patient. Similarly, EKGs receive an F from the US Preventive Service Task Force because—like listening to the neck—people who get these tests are more likely to die or be harmed than those who don’t. Even the much-praised skin exam does not reduce the chance of someone dying of skin cancer but does often lead to harm by identifying and removing lesions that were best left alone. Yes, we will find skin cancers, but the majority are benign, and the bad ones have likely already spread. Our videos explain this better. Labs, too, are not effective for the most part if done to screen for diseases. If someone is tired, or loses weight or feels lousy then labs can help us, but to just order pages of labs and hope to fish for problems is a recipe for disaster. We’ll find stuff and you’ll be glad we did the tests, but it’s more likely than not that “fixing” those problems will send you down a very rocky road that could have been avoided by a wiser doctor.
In terms of cancer screening, only mammograms, colonoscopies, some lung cancer screening (as noted in our previous blog), and pap smears have demonstratable benefit. As we discuss in a video, PSA blood tests for prostate cancer cause far more harm than good. Sure, we may find prostate cancer, we may fix it and (by dousing the body with chemo, radiation, and hormones) push the PSA down to zero, but are we helping you? A third of men have prostate cancer by the time they die, but only 1% of men die of prostate cancer. And it’s such a slow growing cancer (we call it a turtle) that treatment rarely impacts its outcome. Even with aggressive treatment, 1% of men still die of prostate cancer, but the treatment can lead to impotence, incontinence or worse. It’s a bad test that is very profitable to the health care system—over $10 billion a year—but gives you the illusion that your life is saved at a great cost to your body and soul. Other turtle cancers like kidney and non-melanoma skin (squamous and basal) similarly are not impacted by screening; the very few that are lethal are already on the path to killing people before they are discovered and removed. In the last 30 years we have found 4 times the number of kidney cancers than we had prior because we are doing so many CT scans, but the death rate from kidney cancer is unchanged. This is true of skin cancer too. Sure, if you have bleeding in the urine we will look for cancer in the absence of other causes, and if you come to us with an ugly mole growing on your nose we will address it, but these are not screening tests; these are done based on your symptoms and observations, and thus the testing is addressing something you complained about, which by definition means it’s not a screen. Aggressive cancers like melanoma, ovarian, and pancreatic similarly are difficult to screen for. These are called rabbits because they spread so quickly. Once we find them, it’s usually too late.
Screening for non-cancers is similarly more deleterious than helpful. Many patients who see cardiologists gets ekg’s, stress tests (sometimes with radioactive dye), echocardiograms, and even carotid ultrasounds in the absence of any symptoms just to see if anything is wrong. Sounds good in theory, and it pays these doctors quite well, but again there is no evidence to back them up. Let’s say, for instance, your thorough cardiologist gives you a nuclear stress test even though you’re feeling well. The $15,000 cost seems worth it if she tells you that she found a problem. Then you get a $15,000 catheter that finds an 80% blockage, then a $35,000 stent is put in to open the “deadly” blockage and you hug that doctor for saving your life by being conscientious enough to screen you even though you had no complaints. “If you had come in even a few days later you may have died,” the brave doctor says to you with a smile. But is she right? Absolutely not, and ample evidence shows how misleading and deceptive this screening test is. Most people who have heart attacks—up to 90% of them—would have had a normal stress test the day before because most heart attacks don’t occur in parts of our hearts with blockages. In fact, if you have a blockage, it’s very likely that your body has already bypassed it. The catheter she puts into you to find the blockage causes strokes in 1% of people who get them and can also damage our kidneys and lead to severely damaging bleeding in the leg. The stent itself can increase the risk of heart attack and stroke, not lower it. In fact, stents have been shown not to save any lives or prevent any meaningful heart attacks. But they can kill you. So, again, you have the illusion of a saved life from a well-meaning doctor who performed a screening test, but in fact you were put in more danger than if you had never gone to the doctor at all. The same is true for screening carotid ultrasounds and echocardiograms; we may find and fix stuff and let you think that your life was saved, but nothing is farther from the truth.
Whether it’s a bone density test, or labs to pick up hidden cancer, or rectal exams or full body CT scans the result is the same. We may find some stuff, we may tell you that we got to you just in time, we may fill you up with diagnoses and medicines and surgeries, but we are not helping you. We are just medicalizing you, turning you into a collection of numbers and illnesses that we can “fix” at your expense and our profit.
Many books look at this, from Shannon Brownlee’s Overtreated to multiple books by Nortin Hadler and H. Gilbert Welch and John Abramson, to my own books Curing Medicare and Interpreting Health Benefits and Risks, and the data is clear: this form of snake-oil screening helps pad the pockets of doctors and the health industry, and gives you the illusion of cure, but it is dangerous and unethical.
As we age, the problems with screening become far worse. Even beneficial screening tests such as mammograms and colonoscopies and pap smears are harmful over age 75; we may find cancers, we may fix them, but most of them will have been harmless if left alone and those that are lethal will have spread before we find them, while our “fixes” cause elders great harm. Screening later in life can divulge a litany of problems since the older body is cluttered by cancers and blocked blood vessels and calcified heart valves and thin damaged bones. We may tell you we picked up a heart blockage or prostate/breast cancer, we may find a squamous cell skin cancer that was hidden from your view, we may tell you you have osteoporosis or that your labs show stage three kidney disease. But in the absence of symptoms, none of these are going to be helped by medical intervention, which is far more likely to cause harm than benefit.
The data about health screening is clear. At a young age, a few screening tests make sense, but even they are wrought with uncertainty, can lead to harm, and are not as life-saving as the medical community will let you think. But as we age, screening is frankly dangerous and medically negligent. It feeds the medical system, it gives you the illusion of cure, but it is not the best path to a long and happy life.