Over-diagnosis in medicine

Sometimes it can be better to do nothing.

Some in the American medical profession are concerned about the dangers of overzealous medicine. There has been a trend towards detecting health problems too early, convincing healthy people they are sick, and treating them too aggressively.

The latest research, published in December in the Journal of the American Medical Association, is a pointer. It found that in US hospital regions with high rates of CT scans – which are typically ordered to check the lungs and abdomen – many more kidneys are removed. Doctors can see the kidneys too, and often stumble on innocuous cancers that are never going to bother the patient. 1 in 50 of those who undergo the surgery die within a month.

With biomedical companies designing ever more tests, such as breath-tests for cancer, the problem is only going to worsen. A person who presents with, say hoarseness of voice, gets a CT scan that finds a minor tumor somewhere else in the body, which might merit close watching over a period, but is promptly removed in unrelated surgery.

Cancers can grow quickly and some slowly; some even vanish on their own. There are the cancers, which have already spread before tests notice them, and cancers that can be treated before they spread if caught early – and cancers that never spread at all. A new test (liquid biopsy) will tell you that you have cancer, somewhere, but can’t tell you where. This then poses question, ”How many fruitless tests will you have to go through to find the growth that may never do you any harm?”

Take breast cancer: some doctors think mammograms are over-used. Screening in the US has found many non-progressing breast cancers, but has helped very little in catching fast-progressing cancers early on. Among 1000 women who are screened every year for a decade from the age of 50, roughly one will avoid death through breast cancer, more than 500 will have at least one false alarm and 10 will be treated needlessly. Meanwhile, women are naturally anxious as they wait for a biopsy and about the risk of undergoing chemotherapy for a cancer that is basically benign. (Based on an article by Wendy Glauser, New Scientist)

There is a temptation to blame the medical profession alone for over-diagnosis. After all, they have, in America (in contrast to Europe), a heavy financial incentive to treat as much as possible. But the truth is more complicated. Many (not all!) patients, too, want to treat every condition they are subject to. A huge part of Medicare expenditure is given over to treating a small number of rich, old people to keep them alive, come what may. It must be hard to say “no”. Do people want doctors to deal just with pressing, acute problems, or use the modern power of medical technology to search diligently for something, anything, wrong? I fear – the latter. And up go the premiums!