Over-diagnosis of thyroid cancer in Korea

February 13th, 2015

February 13, 2015

By Sang Won Shin, MD
For the Lown Institute

In 1997, in the small town of Young-kwang in the southwest, a doctor opened a private internal medicine clinic. For some reason, he decided to provide patients ultrasonography screening for thyroid cancer. It did not take long for him to be admired for saving many lives by detecting early thyroid cancers. The news rapidly spread to the nearby towns and cities. And clinics in other areas subsequently joined in the frenzy of detecting thyroid cancers with ultrasonography screening. It was not a bad thing for doctors to detect early cancers since that supports them and they gain a reputation for saving lives.

Suddenly the incidence of thyroid cancer in Jeon-nam Province, where Young-kwang is located, drastically soared. However, an epidemiologist, Dr. Choi at the Jeon-nam National University School of Medicine in Kwnag-ju, the regional center of Jeon-nam Province, suspected that the rising incidence of thyroid cancer may be related to the nuclear power plant operating just 30 km away from Young-kwang. He immediately began epidemiological studies but found nothing that implicated the plant as the real culprit. His conclusion was that the rising incidence of thyroid cancer was a direct result of wide spread screening of ultrasonography of thyroid. But his assessment did not receive much attention from the medical community or the general public. Many people reasoned it is not a bad idea to detect early thyroid cancer since it would help save lives.

Another turning point came when the Korean government initiated an ambitious nationwide cancer screening program, targeting stomach, liver, breast and colon cancers. It recommended that every adult have annual cancer screenings, starting in 1999, and a campaign for it kept mentioning the mantra, “early detection saves lives.” More fuel on the fire. And more thyroid cancers found.

Many private and government clinics specializing in cancer screenings mushroomed, and they started offering thyroid and breast ultrasonography screening as an optional choice. Surely the proximity of the breast and thyroid would lead women to undergo simultaneous thyroid and breast cancer ultrasonography screenings. As expected, soon the incidence of thyroid cancer soared in whole country.

Since last year, the incidence of thyroid cancer in Korea has increased at an alarming rate and it is unprecedented in the medical history of the world. It increased by almost 25% annually from over the last 10 years and almost 30 fold during the last two decades. According to latest Korean government statistics (2012), the incidence rate was 81/100,000 which is almost 10 fold higher than average global incidence rate, 15 fold higher than in England, six folds higher than in United States. Today, it seems almost everyone or someone they know has had his or her thyroid removed. Every week in the news, we learn that celebrities, like singers and movie stars, are having their thyroids removed, many of them in their 30s, 20s and younger.

Nearly every university hospitals has “specialized thyroid cancer centers,” with lavishly decorated interiors, offering full courses of therapy within a week from thyroid screening, including surgery and radiotherapy. These resemble a factory assembly line.

More than 90 percent of those diagnosed with this cancer are treated with surgery and 10 percent experience complications, such as voice change, periodic spasm due to hypoparathyroidism and even death. Moreover, as the thyroid is the essential organ for sustaining life, most patients need lifelong thyroid hormone replacement therapy with varying degrees of effectiveness. Other concerns include psychological stress and the waste of more than $2 billion in healthcare resources–unnecessary care.

Since 2012, Korea is the only country in the world where thyroid cancer is the most common cancer, comprising 30 percent of all cancer. Because Korea’s cancer statistics are seriously skewed with more thyroid cancer data included, the government decided to provide two kinds of cancer statistics: one with thyroid data and one without.

On March 18, 2014, a group of eight physicians, including myself, formed a group called  “The Coalition of Doctors to Prevent Over-diagnosis of Thyroid Cancer.” We held a press conference to urge that ultrasonography screening for thyroid cancer be discontinued in Korea. What followed were more than a dozen public debates on the issue of over-diagnosis of thyroid cancer, which took place in the public broadcasting system. Several hearings were also held by Korea’s health ministry and national congress.

Recently, articles on over-diagnosis of thyroid cancer in Korea were published in NEJM (“Epidemic” – Screening and Overdiagnosis,” November 6, 2014) and the Lancet (“Korea’s Thyroid-Cancer and “Overdiagnosis and screening for thyroid cancer in Korea, November 22, 2014).  Yet the attitude of most endocrinologists and thyroid surgeons did not change and they even condemn the Coalition, publishing several books advocating their views and strongly asserting that ultrasonography screening for thyroid cancer saves lives.

The majority of people still believe in doctors, and they cannot say no to those who treat their thyroid cancer. Because of the government policy advocating “early detection of cancer saves lives,” thyroid cancer screening is still going strong. Above all, the Korean government, waiting timidly to see which way the wind is blowing, has taken no action against this tragic modern disaster.

Over-diagnosis and overtreatment of thyroid cancer in Korea shows how abusive this modern technology can harm people, in an extreme form. As we see the incidence of thyroid cancer rising in other parts of the globe, without declining o mortality, it should be regarded as a serious warning signal of worldwide overuse of medical technology.

Appendage: It is noted that Cho, Young-jung, a program director of Korea Broadcast System (KBS), helped me write this essay.

Sang Won Shin MD is a physician in the Department of Medical Oncology, Korea University Hospital, Seoul, Korea