Screening for thyroid cancer should be discouraged to prevent an “epidemic of diagnosis”—like the one occurring in South Korea—from happening in the United States and other countries, according to the authors of an analysis of the South Korean screening program. That study was published in The New England Journal of Medicine.1
In an op-ed piece in The New York Times,2 one of the study’s authors, H. Gilbert Welch, MD, MPH, further explained the implications of the study. Dr. Welch, Professor of Medicine at the Dartmouth Institute for Health Policy and Clinical Practice, Hanover, New Hampshire, cautioned readers, “Having doctors not look too hard for early cancer is in your interest.”
That message might seem jarring to patients used to hearing that early detection is their best defense against cancer. What they need to understand, Dr. Welch said in an interview with The ASCO Post, is that the vast majority of cancers discovered by thyroid cancer screening are papillary thyroid cancers, many of which will never become evident during a person’s lifetime except through screening or as incidental findings from imaging tests near the thyroid.
Once found, these cancers are usually treated with radical thyroidectomy, requiring lifelong thyroid replacement. Hypoparathyroidism and vocal-cord paralysis has occurred as a surgical complication in a small percentage of patients.
Makes Sense in Some Cases
“Of course, screening makes sense in some situations: in particular for people who are at a genuinely high risk for the cancer—those with multiple cancer deaths in their family history. People at average risk who expect to live long enough to experience the potential benefit in the future—and who are willing to accept the chance of harm from unneeded treatment now—may also decide that the screening makes sense for them,” Dr. Welch wrote in The New York Times.2
“It is not that all early detection is bad,” he told The ASCO Post. “The question is: how early? If we always go in the same direction, looking for smaller and smaller lesions, it is a recipe for finding something wrong with all of us. So we have to understand that this question of how early is going to become more important as we are increasingly able to identify tiny perturbations in immune function or biochemical information, or genetic marker or imaging structural abnormalities.”
Understanding the Balances
“When we are talking about screening, we are talking about trying to get ahead of symptoms. And whenever you try to get ahead of symptoms, you are going to be treating some people for something that is never going to bother them. That treatment may lead to anxiety. It may cost them a lot of money, and can even lead to death,” Dr. Welch said.
“There are balances, and it is a matter of having people understand those balances, and also having the system understand those balances—so we are not always going to the most extreme, looking for the smallest abnormality, trying to find the most abnormalities, and turning the most people into patients.” ■
Disclosure: Dr. Welch reported no potential conflicts of interest.
References
1. Ahn HS, Kim HJ, Welch HG: Korea’s thyroid-cancer “epidemic”—screening and overdiagnosis. N Engl J Med 371:1765-1767, 2014.
2. Welch HG: An epidemic of thyroid cancer? New York Times, November 5, 2014.
