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Thyroid cancer is overdiagnosed and overtreated, say Mayo doctors

Dr. Juan Brito discusses the Mayo findings.

New imaging technologies have led to the overdiagnosis of thyroid cancer, exposing thousands of people to unnecessary, costly, and potentially harmful treatments, according to a new analysis from three doctors at the Mayo Clinic in Rochester.

The problem is especially acute here in the United States.

Because of their concern, the Mayo doctors are recommending that a new term be used to describe low-risk thyroid lesions — a term that will better convey the minimal risk that such lesions pose to a patient’s health and that will steer both patients and doctors away from unnecessarily treating them.

“We need to rename them,” said Dr. Juan Brito, an endocrinologist and one of the authors of the analysis, in a phone interview Monday. “We need to put them in a different category.”

The analysis was published Tuesday in the journal BMJ.

A perplexing rise in diagnoses

During the past 30 years, the incidence of diagnosed cases of thyroid cancer has tripled in the United States, from 3.6 cases per 100,000 people in 1973 to 11.6 cases in 2009.

“It’s become one of the fastest-growing cancer diagnoses,” said Brito.

The rising incidence rate has been observed worldwide, but not uniformly, he added. Sweden, Japan and China, for example, have experienced a minimal increase in the incidence of this particular cancer.

Furthermore, almost all of the new cases of thyroid cancer being diagnosed — 90 percent — involve small papillary tumors, which studies have shown are very slow-growing and highly unlikely to go on to cause symptoms much less death.

That factor most likely explains why the death rate for thyroid cancer has remained the same while the diagnosis of new papillary thyroid cancers as skyrocketed.

Key factors behind the rise

As Brito and his colleagues, Dr. John Morris and Dr. Victor Montori, explain in their paper, more papillary lesions are being diagnosed because of advances in high-tech imaging technologies, such as ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI), which can now detect thyroid nodules as small as 2 millimeters.

Another factor are reimbursement policies that reward physicians for the use of those technologies, the Mayo doctors add. The routine use of neck ultrasonography has increased at least 80 percent since 1980.

Research has also shown that higher-income Americans — particularly those with good health insurance — are much more likely to be diagnosed with thyroid cancer than those in lower income brackets.

“The access to technology as well as the use and sometimes the abuse of that technology is driving the overdiagnosis,” said Brito.

Unnecessary treatments

Overdiagnosis often leads to overtreatment, including unnecessary surgery, Brito and his colleagues point out in their paper. Indeed, the number of thyroidectomies (surgeries that remove all or part of the thyroid gland) rose 60 percent in the United States between 1996 and 2006.

The thyroidectomy procedure is costly and associated with several serious and permanent complications, including nerve injury to the larynx. People who’ve had a total thyroidectomy — or even, in some cases, a partial one — must also take thyroid replacement therapy for the remainder of their lives, a treatment that poses its own health risks.

Radioactive iodine treatment is also being increasingly prescribed in the United States for low-risk papillary lesions. In 1973, one in 300 patients with thyroid cancer received these treatments. In 2006, that number had grown to two in five patients. Yet radioactive iodine treatments are not recommended for people with low-risk thyroid lesions. The treatments are associated with a reduced quality of life and a risk of developing other types of cancer, including leukemia and cancer of the salivary gland.

Need for new nomenclature

Brito and his colleagues acknowledge that there may be yet-unidentified reasons for the rapid rise in the incidence of thyroid cancer — radiation exposure from the widespread use of CT scans, for example. But the discrepancy between the incidence and death rates and the varying country-by-country incidence rates point most strongly to overdiagnosis as the reason behind the rise.

They call for doctors to engage their patients in more decision-making, and to explain to their patients that in many cases active surveillance rather than surgery is the most appropriate treatment for thyroid lesions.

“Patients can be reassured that if nodules later show more aggressive behavior the evidence suggests no additional harm from delayed surgical treatment,” the Mayo doctors write.

They also recommend that small papillary lesions be renamed macropapillary lesions of indolent course (micro PLICs) to more accurately reflect their minimal health risk to the patient.

Most thyroid lesions that are found “are not destined or meant to cause harm,” said Brito.

“But it’s very difficult not to do something when you have the label of cancer,” he added. “By removing that label, we can reframe the level of care for them.”

The analysis by Brito and his colleagues can be read in full on the BMJ’s website. The Mayo Clinic has also released a video in which Brito discusses the paper’s findings and recommendations.

Comments (1)

  1. Submitted by Cindy Lafferty on 07/24/2014 - 09:04 pm.

    Thyroid Cancer Overdiagnosed and Overtreated

    I am a perfect example of why Papillary Thyroid cancer should be treated because I am also an example of the wait and see approach. I was under the care of an incompetent endocrinologist who told me that my thyroid nodules were benign for over 8 yrs. He said,”We would just keep an eye on them with ultrasounds”.

    Meanwhile, I developed a rare and progressive form of Idiopathic Chronic Erythema Multiforme. I blistered throughout my entire digestive tract with my tongue sloughing off in large sheets. My tongue would then swell while a yeast infection set in each time it peeled. My eyes blistered and my corneas dried out. It was extremely painful.My hands also blistered and peeled in large sheets until they bled. Thankfully a dermatologist at the University Of Pennsylvania was able to stop the blisters with high doses of oral steroids,steroid creams and eye drops,and Plaquenil (an antimalarial drug).

    Quite by accident,I saw another endocrinologist (filling in for my usual endo) for an unrelated issue, who suspected my nodules were cancerous. The biopsy was positive. This time, I made sure I found the best doctors in my region. My surgeon was the head of endocrinology/oncology surgery and said that it was cancer all along after viewing all of my scans from the previous 8 years. A total thyroidectomy was performed. The surgery took an hour longer than expected because the surgeon had to chisel the cancerous rock off my left vocal cord. Full pathology staged my cancer as a T3 Papillary Carcinoma with a Tall Cell variant.

    Before I went for RAI treatment, my dermatologist told me that I would have to stop the Plaquenil. I feared the return of the blisters. I am happy to say that I had one very small flare and never blistered again. It wasn’t until a couple of months later that the correlation was discovered. While paraneoplastic (another disorder caused by cancer) conditions are not linked with thyroid cancer, my dermatologist firmly believes this was the case for me.

    So, you see, technically that wait and see attitude was detrimental to my health. I suffered physically and emotionally for almost 8 yrs.The cost for medicines and treatments, for doctors trying to diagnose and stop the EM,for multiple trips to the ER for IV steroids for a swollen tongue and throat, among countless more bills and hours lost was astronomical.

    Rather than limit your belief that thyroid cancer (and particularly Papillary thyroid cancer) is overdiagnosed, why not expand your mind to,”What are the causes of why we are having epidemic cases of Thyroid Cancer?”. Maybe we should be looking at radiation exposure and other causes.
    I am just grateful that my new doctors acted in my best interest and did not take the easy way out like my old endocrinologist. I encourage the doctors in this article to open their minds and seek answers to deeper issues. That will truly be in their patient’s best interest, not a wait and see approach.

    Dr. Brito gave many recommendations. I recommend that Dr. Brito’s patients view this video and report. I have no doubt that if they see this, Dr. Brito will not only be a doctor with no patience for Thyroid Cancer but also, a doctor with no patients.

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