An example of testing run amok

In his book, Overdiagnosed, Dr. Welch tells the following story:

As part of her annual checkup, a sixty-five-year-old woman was screened for osteoporosis. She was told that her bone density was a little below average for her age and that she was at risk for bone fractures (she did not actually have osteoporosis.) Her doctor started her on hormone replacement therapy until it was learned that such therapy increased the risk of heart attack and stroke as well as breast cancer. So she was put on a different medication and developed a terrible pain when swallowing. As a result, she was sent to a gastroenterologist, who performed an endoscopy and found that she had severe inflammation and ulcers in her esophagus—a known side effect of the drug she had been taking. She was switched to another medicine and the problem with her esophagus went away, but she developed a painful rash and was referred to a dermatologist who suggested she stop the medication. The rash went away, but treatment continued.

Next she was referred to an endocrinologist who did a thorough evaluation of all her glands and hormones, including a careful physical exam of her thyroid gland, on which the doc thought he felt a lump. So she was sent to a radiologist, who did an ultrasound exam of her thyroid and found three lumps. To check for cancer of her thyroid, she had needles stuck in all the lumps to remove some fluid (containing cells) from each. Under the microscope, the pathologist thought some of the cells looked suspicious. He thought that perhaps her thyroid should be removed, so she was referred to a surgeon. Luckily for her, the surgeon put a stop to the whole business, knowing that nearly all adults have some evidence of thyroid cancer. The woman, who was fine before the disastrous bone density screening, is again fine.

No sooner had I written this example, than I came across a study reported in the November 6, 2014 issue of The New York Times with the headline: “Study Points to Overdiagnosis of Thyroid Cancer.” The story refers primarily to South Korea, where they began screening for thyroid cancer 15 years ago. (In the US, thyroid cancer rates have more than doubled since 1994, again, because of overdiagnosis.)

Next week: Over-diagnosing thyroid cancer.

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.