Skip to content

Tag: thyroid cancer

Published on Leave a comment on Overdiagnosed and Overtreated For Thyroid Cancer

The problem of overdiagnosis and overtreatment has been discussed in a number of posts on this site. And back in April 15, 2016 I posted that a type of noninvasive thyroid cancer had just been reclassified as a noncancer. Now a study in the prestigious New England Journal of Medicine finds that looking at 12 countries (including the USA): "Overall, we estimate that more than 470,000 women and 90,000 men may have been overdiagnosed with thyroid cancer over two decades in these 12 countries..."

The researchers further state that the "vast majority" of these patients received a diagnosis of small, low-risk papillary carcinomas, and they underwent surgery and other treatments, but these interventions have not shown "benefits in terms of improved survival". In fact, studies show that watchful waiting is just as effective. From Medscape:

Thyroid Cancer Overdiagnosis in Half a Million Patients

A large fraction of thyroid cancer cases represent overdiagnoses, and at least half a million patients, most of them women, may have received unnecessary surgery and other cancer treatments, say researchers from the the International Agency for Research on Cancer (IARC), in Lyons, France.

Their warning about an epidemic of thyroid cancer overdiagnosis comes from an analysis of cancer registry data from 12 countries published August 17 in the New England Journal of Medicine . Salvatore Vaccarella, PhD, and colleagues at the IARC estimate that more than 470,000 women and 90,000 men may have been overdiagnosed withthyroid cancer in 12 "high-income" countries (Australia, Denmark, England, Finland, France, Italy, Japan, Norway, Republic of Korea, Scotland, Sweden, and the United States) from 1987 to 2007.

Most of these thyroid cancers were small, low-risk papillary carcinomas, they note. The "vast majority" of these patients underwent total thyroidectomy, and a "high proportion" also received neck lymph-node dissection and radiotherapy, but these interventions do not have "proven benefits in terms of improved survival," the researchers point out...."However, if we take the most recent available period, 2003 - 2007, as typical of current practice, we estimate that overdiagnosis in women accounts for 90% of thyroid-cancer cases in South Korea; 70 to 80% in the United States, Italy, France, and Australia; and 50% in Japan, the Nordic countries, and England and Scotland."

The overdiagnosis is blamed on increasing medical surveillance and the introduction of new diagnostic techniques, such as neck ultrasonography (since the 1980s) and, more recently, CTscanning and MRI. This new technology has led to the detection of a large number of indolent, nonlethal diseases that exist in abundance in the thyroid gland of healthy people of any age, the researchers comment, adding that most of these tumors are very unlikely to cause symptoms or death....."It is fair to say that the large number of thyroid cancers being diagnosed represent an epidemic of diagnosis, or an epidemic of medical testing, rather than an epidemic of true disease."

These results also mean that most patients are receiving treatment that does not benefit them and that subjects them to risks of injury to the voice, permanent hypoparathyroidism, as well as the attendant risks of radioactive iodine treatment, he pointed out.  

The researchers caution against systematic screening for thyroid cancer and overtreatment of nodules <1 cm. "Watchful-waiting approaches should be considered a research priority and a preferable option for patients with low-risk papillary thyroid cancers," they say. Studies from Japan suggest that immediate surgery and watchful waiting are equally effective in preventing mortality, Dr Vaccarella said. One study showed that of 1235 patients with papillary microcarcinomas, only 3.5% experienced clinical progression of disease during a 75-month follow-up, and there were no deaths.

At Memorial Sloan Kettering Cancer Center, active surveillance has been offered to patients with low-risk, small, intrathyroidal cancers for several years, Dr Morris said. "Our results have mirrored the Japanese results, and fewer than 5% of patients end up showing any signs of tumor growth under close observation," he said.

Published on Leave a comment on Noninvasive Thyroid Cancer Is No Longer Cancer

For the first time ever, one type of cancer has been reclassified as a non-cancer. An international panel of pathologists and clinicians has reclassified a type of thyroid cancer to reflect that it is noninvasive and has a low risk for recurrence.The panel renamed encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). There has been concern for a while of the costs (financial, physical, and mental) of the overdiagnosis and overtreatment for something that won't spread (it's "indolent" and "low-risk").

There have been discussions for some time now in the medical community regarding the move away from the word "cancer" in the description of early stages of both breast and prostate cancer. In 2013, a medical team sanctioned by the National Cancer Institute proposed that a number of premalignant conditions, including ductal carcinoma in situ and high-grade prostatic intraepithelial neoplasia, should no longer be called "cancer." Instead, the conditions should be labeled something more appropriate, such as indolent lesions of epithelial origin (IDLE), the group suggested. " Use of the term 'cancer' should be reserved for describing lesions with a reasonable likelihood of lethal progression if left untreated," the group said at the time.

From Futurity: NONINVASIVE THYROID ‘CANCER’ ISN’T CANCER

The reclassification of a noninvasive type of thyroid cancer that has a low risk of recurrence is expected to reduce the fears and the unnecessary interventions that come with a cancer diagnosis, experts say. The incidence of thyroid cancer has been rising partly due to early detection of tumors that are indolent or non-progressing, despite the presence of certain cellular abnormalities that are traditionally considered cancerous, says senior investigator Yuri Nikiforov, professor of pathology at the University of Pittsburgh.

“This phenomenon is known as overdiagnosis,” Nikiforov says. “To my knowledge, this is the first time in the modern era a type of cancer is being reclassified as a non-cancer. I hope that it will set an example for other expert groups to address nomenclature of various cancer types that have indolent behavior to prevent inappropriate and costly treatment.”

In particular, a tumor type known as encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) has increased in incidence by an estimated two- to three-fold over the past 20 to 30 years and makes up 10 to 20 percent of all thyroid cancers diagnosed in Europe and North America. Although studies have shown EFVPTC is not dangerous, it is typically treated as aggressively as other types of thyroid cancer. At the recommendation of the National Cancer Institute, the panel sought to revise the terminology and to see if the word “cancer” could be dropped from its name.

As reported in JAMA Oncology, two dozen experienced pathologists from seven countries and four continents independently reviewed 268 tumor samples diagnosed as EFVPTC from 13 institutions....In a group of more than 100 noninvasive EFVPTCs, there were no recurrences or other manifestations of the disease at a median follow-up of 13 years. They decided to rename EFVPTC as “noninvasive follicular thyroid neoplasm with papillary-like nuclear features” or NIFTP. The new name cites key features to guide pathologists in diagnosis, but omits the word “cancer,” indicating that it need not be treated with radioiodine or other aggressive approaches.

“We determined that if NIFTP is carefully diagnosed, the tumor’s recurrence rate is extremely low, likely less than 1 percent within the first 15 years,” Nikiforov says. “The cost of treating thyroid cancer in 2013 was estimated to exceed $1.6 billion in the US. Not only does the reclassification eliminate the psychological impact of the diagnosis of ‘cancer,’ it reduces the likelihood of complications of total thyroid removal, and the overall cost of health care.”

Published on Leave a comment on Overdiagnosis of Thyroid Cancer?

The issue of overdiagnosis and overtreatment rears its head again - this time in a study looking at thyroid cancer detection and death rates. The death rate from thyroid cancer has stayed the same since 1935, as has the number of thyroid cancers presenting with symptoms of thyroid cancer. But...the number of new cases of silent thyroid cancer -- the kind where patients have no symptoms -- almost quadrupled in recent years, and these are the tiny cancers that probably won't cause a problem in the person's lifetime. The researchers then discuss how NOT to find these tiny silent thyroid cancers, so as to avoid overdiagnosis and the harms of overtreatment. From Science Daily:

Increased detection of low-risk tumors driving up thyroid cancer rates, study finds

Low-risk cancers that do not have any symptoms and presumably will not cause problems in the future are responsible for the rapid increase in the number of new cases of thyroid cancer diagnosed over the past decade, according to a Mayo Clinic study published in the journal Thyroid. According to the study authors, nearly one-third of these recent cases were diagnosed when clinicians used high-tech imaging even when no symptoms of thyroid disease were present.

"We are spotting more cancers, but they are cancers that are not likely to cause harm," says the study's lead author, Juan Brito Campana, M.B.B.S., an assistant professor of medicine at Mayo Clinic. "Their treatment, however, is likely to cause harm, as most thyroid cancers are treated by surgically removing all or part of the thyroid gland. This is a risky procedure that can damage a patient's vocal cords or leave them with lifelong calcium deficiencies." Dr. Brito says harm is not limited to physical suffering. "Treatment can cause financial hardship for patients and their families and for society as a whole, as millions of dollars are spent for unnecessary and problematic surgeries," he says....At the same time, the incidence of thyroid cancer is increasing more rapidly than that of any other cancer and is on track to become the third most common cancer in women.

In this study, Dr. Brito and his colleagues drew on data from the Rochester Epidemiology Project. They analyzed the records of 566 men and women who were diagnosed with thyroid cancer in Olmsted County, Minnesota, between 1935 and 2012. Specifically, they examined the number of new cases of thyroid cancer, the deaths due to the disease, and the method of diagnosis.

Researchers found that the number of new cases of thyroid cancer doubled in recent years -- from 7.1 per 100,000 people from 1990 to 1999 to 13.7 per 100,000 people from 2000 to 2012. Over the same period, the number of new patients with thyroid cancer presenting with symptoms of thyroid cancer remained the same. In contrast, the number of new cases of silent thyroid cancer -- the kind where patients have no symptoms -- almost quadrupled. The proportion of patients with thyroid cancer who die of the disease has not changed since 1935.

The study found that the most frequent reasons for identifying silent thyroid cancer were review of thyroid tissue removed for benign conditions (14 percent); incidental discovery during an imaging test (19 percent); and investigations of patients with symptoms or palpable nodules that were clearly not associated with thyroid cancer, but triggered the use of imaging tests of the neck (27 percent)."We are facing an epidemic of diagnosis in thyroid cancer," says Dr. Brito. 

Researchers say one approach to curtail the detection of these lesions would be to limit the use of certain imaging technologies. Another tactic would be to engage patients in deliberating their treatment options. In many cases, active surveillance may be preferred over surgery by patients with small, relatively benign cancers that could take decades to grow to any appreciable size or cause life-threatening problems. Dr. Brito thinks something as simple as not using the word "cancer" to refer to these small and silent thyroid lesions could reduce the number of unnecessary treatments for patients with a more favorable prognosis. Rather than calling these lesions thyroid cancer, he would recommend a less emotionally charged term, such as papillary lesions of indolent course.

Thyroid gland. Credit: Mayo Foundation for Medical Education and Research