Low-Risk Thyroid Cancer Overdiagnosed, Overtreated

Megan Brooks

August 28, 2013

"Zealous" imaging is fueling the overdiagnosis and overtreatment of subclinical low-risk thyroid cancer in the United States, researchers warn in a new report.

"There has been an increase in low-risk thyroid cancer worldwide, but in the United States, the increase has been much more dramatic," said the report's first author, Juan P. Brito, MD, from the knowledge and evaluation research unit at the Mayo Clinic in Rochester, Minnesota.

Dr. Juan Brito

The incidence of thyroid cancer in the United States has tripled in the past 30 years, from 3.6 per 100,000 in 1973 to 11.6 per 100,000 in 2009, making it one of the fastest growing diagnoses, Dr. Brito and colleagues note in their report, which was published online August 27 in BMJ.

The vast majority of these incident cancers are small low-risk papillary thyroid cancers that are unlikely to ever progress enough to cause symptoms or death, they note.

The fact that the death rate for these cancers has remained stable (0.5 per 100,000 in 1979 and in 2009) in the face of rising incidence provides "the most compelling evidence" of overdetection and overtreatment, they point out.

Technology and Policy to Blame

"These indolent thyroid cancers are being discovered because we have the technology to see nodules as small as 2 mm. The fact that we can do biopsies at the bedside is triggering overdiagnosis and overtreatment of papillary thyroid cancer," Dr. Brito told Medscape Medical News.

"Ready access to portable ultrasound machines together with policies which reimburse physicians for imaging have promoted the routine use of neck ultrasonography, which has increased by 80% in general endocrinological services over the past few decades," the authors write.

"Ultrasound has become so inexpensive that you can scan everybody that comes in just like you listen to their heart," said Damian Dupuy, MD, director of tumor ablation at Rhode Island Hospital and professor of diagnostic imaging at The Warren Alpert Medical School of Brown University in Providence. He was asked by Medscape Medical News to comment on the report.

"Are you helping them by doing that? No. But if you can charge for it, you're helping your own pocketbook. That's really what's happening. It's the fee-for-service model that is pushing testing, follow-up, and biopsy, because you get paid to do that," he explained.

Otis Brawley, MD, chief medical officer for the American Cancer Society, told Medscape Medical News that "overdiagnosis of thyroid cancer is a huge problem, and overtreatment of thyroid cancer is an even greater problem. Overdiagnosis is finding something that looks like cancer that will never kill someone. A lot of these quiet things are found because we are an imaging-crazy society right now."

Dr. Brawley explained that "we do not have a single study showing that thyroid cancer screening saves lives, and we don't have a single professional or medical organization that recommends thyroid cancer screening. The American Cancer Society, for 20 years, has recommended against it."

Dr. Brito and colleagues warn that increased detection of indolent papillary thyroid cancer sets the stage for exposing patients to unnecessary, potentially harmful, and costly treatment that is not consistent with their prognosis.

Thyroidectomy, for example, is not only costly but carries the risk for complications such as permanent hypoparathyroidism, hypocalcemia, and laryngeal nerve injury. In the United States, the number of thyroidectomies for thyroid cancer has risen by 60% during the past 10 years, at an estimated cost of $416 million, the authors report.

In addition, the use of radioactive iodine in patients with low-risk thyroid cancer increased from 1 in 300 patients to 2 in 5 patients between 1973 and 2006, despite recommendations against using it, they point out.

"There is some evidence to suggest that the majority of patients who have very small indolent thyroid tumors might not actually benefit from aggressive treatment," Dr. Brito told Medscape Medical News.

Dr. Brito and colleagues say the uncertainty about the benefits and harms of immediate treatment for low-risk papillary thyroid cancer "should spur clinicians to engage patients in shared decision making."

"We need to discuss with patients whether they actually need surgery or not, putting the patient in the center of the decision-making process," Dr. Brito said in an interview. "If you discuss the benefits and harms, sometimes they might not choose surgery; they might be willing to have active surveillance."

Change in Nomenclature?

Dr. Brito and colleagues say that the cancer label for indolent papillary cancer is a problem. "Cancer raises fear and anxiety in patients and clinicians, and labeling indolent lesions as papillary thyroid cancer causes unnecessary distress," they write.

"Let's face it, if you are a patient and it comes back cancer, you want it out," Dr. Dupuy added.

Dr. Brito and colleagues propose renaming small indolent thyroid lesions to something that conveys their favorable prognosis. "We suggest micro papillary lesions of indolent course, or microPLIC," Dr. Brito said. MicroPLIC would describe low-risk lesions (smaller than 20 mm in patients with no family history or radiation exposure and no ultrasound evidence of extraglandular invasion).

A change in nomenclature could reframe the care of these patients and prevent their overtreatment, he said. It might also improve recruitment into trials in which 1 group entails active surveillance rather than immediate treatment. "We need a randomized clinical trial of active surveillance in microPLIC; changing the name now will help," Dr. Brito said.

Dr. Brawley cautions that although "it's a little premature to start using the term, I do think it's time to start having that discussion."

Renaming a disease is not a novel concept. It has already occurred in other "cancers," including papillary urothelial neoplasia of low malignant potential (from grade 1 papillary transitional cell carcinoma of the bladder), atypical lipomatous tumor (from well-differentiated liposarcoma), and cervical intraepithelial neoplasia (from cervical cancer).

More recently, there have been proposals to remove the term "cancer" from early lesions in the breast (such as ductal carcinoma in situ) and the prostate, and to instead use a term such as "indolent lesions of an epithelial origin."

The analysis by Dr. Brito and colleagues is part of a series looking at the risks and harms of overdiagnosis in a range of common conditions, which is part of the BMJ Too Much Medicine campaign, designed to help tackle the threat to health and the waste of money caused by unnecessary care, according to the journal.

Dr. Brito and colleagues, Dr. Dupuy, and Dr. Brawley have disclosed no relevant financial relationships.

BMJ. Published online August 27, 2013. Abstract


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