Thyroid cancer is extremely difficult to beat and requires vigorous and painful treatment. So how would you feel if you were diagnosed with thyroid cancer, and endured all of the treatment necessary to beat it only to find out that you never had the cancer to begin with?
The New York Times reports on a study that focuses on the over diagnosis of thyroid cancer.
Where is over-diagnosis happening the most? It is actually happening all over the world. One expert called it a ‘tsunami of thyroid cancer’.
The study shows that from South Korea to Europe to the U.S. doctors are over-diagnosing thyroid cancer. Researchers found that the number of thyroid cancer cases in the United States has more than doubled in the last twenty years.
Is the number of thyroid cancer cases actually going up or are physicians mistaken?
“Cancer experts agree that the reason for the situation in South Korea and elsewhere is not a real increase in the disease. Instead, it is down to screening, which is finding tiny and harmless tumors that are better left undisturbed, but that are being treated aggressively,” according to The Times.
What type of testing goes on in the United States for thyroid cancer? There is no formal screening in the United States and Europe. But widely used screening programs for thyroid cancer, scans for other conditions, (such as ultrasound exams of the carotid artery in the neck or CT scans of the chest) are finding small thyroid tumors.
Are these tumors harmful?
These tumors are often not harmful yet physicians are prescribing aggressive treatment to patients for them.
Are there more fatalities now from thyroid cancer? “Although more and more small thyroid cancers are being found, however, the death rate has remained rock steady, and low. If early detection were saving lives, death rates should have come down,” according to The New York Times.
What did researchers realize?
The study showed that there were more cancers detected and treated but no change in the death rate. This showed researchers that many of the cancers they are finding and treating were not harmful. Researchers are calling this phenomenon over-diagnosis, finding cancers that did not need treatment because they were increasing very slowly or not at all.
Would these cancers ever cause a problem if they went untouched?
No. Researchers say if left alone, they would most likely never cause problems. Over-diagnosis is extremely hard to fight. The study showed that pathologists cannot tell which small tumors are harmful and most people hear the word ‘cancer’ and do not want to take a risk. They want the possible cancer eradicated.
In South Korea doctors are over-screening and now thyroid cancer is the most common cancer in the country, but in most cases the cancer isn’t even harmful. Cancer experts say that other countries should look at this issue and learn from it. Experts are worried about how many perfectly healthy people are being harmed.
Dr. Brawley, the chief medical officer of the American Cancer Society, told The Times, “It’s a warning to us in the U.S. that we need to be very careful in our advocacy of screening. We need to be very specific about where we have good data that it saves lives.” He also said that colon, lung and breast cancer cases are also often a result of over-diagnosis.
The paper on the surprising increase in thyroid cancer diagnoses was published in the New England Journal of Medicine last week. The authors of the study say that not only did the number of diagnoses escalate as screening became popular, but also that the newly detected cancers were very tiny ones in most cases. These small cancers, which are called papillary thyroid cancers, are the most common type and are the sort usually discovered with screening. These small cancers are known to be the least aggressive or harmful.
What is causing this trend?
Dr. Welch from Dartmouth co-authored the paper and said an environmental toxin or infectious agent did not cause the over-diagnosis epidemic. “An epidemic of real disease would be expected to produce a dramatic rise in the number of deaths from disease. Instead we see an epidemic of diagnosis, a dramatic rise in diagnosis and no change in death,” according to Dr. Welch.
Why are thyroid cancers difficult to detect?
Thyroid cancer is usually indolent. The research showed that on autopsy, around one third of people have tiny thyroid cancers that went undetected in their lifetime.
What happens once a cancer is found?
Treatment is onerous and usually the thyroid is removed. Patients have to then take thyroid hormones for the remainder of their lives. For some people the replacement hormones are not completely effective. They often end up with chronically low thyroid hormone levels, which lead to feeling depressed and without energy. This is why experts are emphasizing the importance of ensuring that the cancer is harmful before taking irreversible steps to treat it.