As much as 1.5 trillion won ($1.4 billion) is spent every year on thyroid cancer examinations in Korea, a report showed Thursday, as concerns grow about overdiagnosis of the disease.

According to a report released by the National Evidence-based Healthcare Collaborating Agency, Koreans were estimated to have spent somewhere between 120 billion won to 1.5 trillion won a year ultrasonic tests for thyroid cancer.

The research agency made this calculation based on a survey of 800 hospitals across the country. Neighborhood doctors conducted the thyroid examination on 30-60 patients on average last month and large hospitals did so on 80-130 patients, the report said. The average medical fee for an ultrasonic wave examination was 38,000 won, it added.

According to the agency’s survey conducted on some 3,600 citizens, 23.3 percent received an ultrasonic test to check for the disease. For 71 percent of them, the test found no abnormalities. The rest were found to have thyroid nodules, with 2 percent found to have cancer.

Concerns have recently grown that thyroid cancer is being diagnosed excessively, after a group of eight medical doctors claimed that Korean doctors were boosting the number of thyroid cancer patients by conducting an excessive number of ultrasonic wave tests to boost hospital income.

They argued that the large number of tests creates a large number of “false positives” ―- patients that test positive for the cancer but do not actually have the disease. They added that even with genuine cancer patients, the harms of treatment often outweighed the benefits.

The prevalence of thyroid cancer in Korea surged by 30 times in the last 30 years. The rate is now 10 times the global average rate, the group of doctors said. They argued that, barring natural disasters or radiation leaks, such a sharp rise was likely to have come through overdiagnosis.

As of 2011, thyroid cancer was the most common type of cancer among Korean patients, with 40,500 cases, followed by stomach cancer and colorectal cancer, according to the National Cancer Information Center. While thyroid cancer was the sixth most common form of cancer among men, it came first among female patients. The mortality rate for thyroid cancer, however, remained one of the lowest.

While some argue that early detection will help treatment, the group of doctors said that it would not usually be helpful due to the characteristics of the disease.

“The progression of thyroid cancer is very slow, as it (usually) takes over 15 years. Symptoms are rarely shown and the disease does not affect the health in many cases,” said Catholic University of Korea professor of medicine Lee Jae-ho, one of the eight doctors who spoke out against the overdiagnosis of thyroid cancer.

“Meaningful early detection is nearly impossible, as the progression of harmful thyroid cancer, which accounts for 0.2 percent of all cases, is very rapid, happening in less than a year,” he added.

The eight doctors claimed that unnecessary thyroid cancer surgery may cause permanent side effects such as vocal cord paralysis. Patients are also forced to take thyroid hormones for the rest of their lives after the operation.

The Korean Thyroid Association denied that the high occurrence rate resulted from overdiagnosis.

“Unlike other countries, Korea offers the checkup for a low cost (to patients), and all comprehensive medical examination programs of hospitals include a thyroid cancer check,” said a KTA official.

But both the doctors and the KTA said it was premature to decide whether to recommend the ultrasonic test for thyroid cancer due to a lack of research.

The Health and Welfare Ministry pledged late last month to draft up a guideline for thyroid cancer checkups as public concerns have escalated. The eight doctors, however, are pessimistic about the government’s plan.

“The ministry is taking action as if the guideline never existed before. It already exists but it’s not being used. The new statement just seems like an attempt to relieve public anxiety,” said Lee.

By Lee Hyun-jeong (rene@heraldcorp.com)