Thyroid Cancer Treatment Remains Too Aggressive, Introduces Avoidable Risks

Further evidence suggests need for reevaluation of treatment for most thyroid nodules, challenging the preference for total thyroidectomy over lobectomy or active surveillance in thyroid cancer.

With Pablo Valderrabano, MD, PhD, and  H. Gilbert Welch, MD, PhD 

The theme of evolving treatment for thyroid cancer seems to be less is more. It appears that the data may be have reached a tipping point in the controversy over recommended approaches to to the management of low-risk differentiated thyroid tumors.

Findings, published in JAMA Otolaryngology-Head & Neck Surgery, support lobectomy as a preferable and equally effective treatment to total thyroidectomy for indeterminate thyroid tumors.1

Less drastic options afford same outcomes for most cases of thyroid cancer.

In a second paper,2 appearing in the New England Journal of Medicine, researchers suggests that when faced with the choice of a lobectomy or a complete thyroidectomy for small papillary thyroid cancer, patients and physicians should also choose the less radical procedure.

Currently, the American Thyroid Association guidelines favor a total thyroidectomy as the recommended treatment for large (> 4 cm) solitary thyroid nodules that are considered indeterminate for cancer.3

Lobectomy Proves Sufficient in Majority of Indeterminate Thyroid Tumors

According to Valderrabano et al,1 more than 90 percent of large solitary thyroid nodules with indeterminate cytology were sufficiently treated with surgical removal of the involved lobe ( lobectomy) rather than by total thyroidectomy.

This research team set out to determine whether clinical outcomes of patients with indeterminate thyroid nodules greater than 4 cm were worse than for nodules smaller than 4 cm, following lobectomy to justify the more aggressive approach.

“We found that tumor size in thyroid nodules with indeterminate cytology was not associated with the probability of the nodule being cancerous,” said Pablo Valderrabano, MD, PhD, a postdoctoral fellow in the Department of Head and Neck-Endocrine Oncology at H. Lee Moffitt Cancer Center and Research Institute. “Furthermore, we were able to establish no association between tumor size and the aggressiveness of the cancer,” he told EndocrineWeb.

The investigators examined a total of 652 indeterminate thyroid nodules grouped according to size.1 The mean age of the patients was 53.1 years old with about 76% of subjects being female.

They found that tumor size was neither associated with rate of malignancy nor the aggressiveness of the cancer, and that most cancerous tumors were considered of low risk in both groups of patients.

Averting Total Thyroidectomy Reduces Others Risks with Same Outcomes

 “Most malignancies, regardless of tumor size, were deemed low-risk cancers and [the patients] had excellent outcomes,” said Dr. Valderrabano. “Almost 85% of the patients with cancer in this series had no evidence of disease at the last follow-up visit, including those presenting with tumors larger than 4 cm in size.”

“Tens of thousands of unnecessary operations are performed each year for diagnostic purposes in patients with cytologically indeterminate thyroid nodules,” said Dr. Valderrabano. This is a problem because, as he pointed out, thyroidectomy also carries increased and avoidable risks.4

“A thyroidectomy not only doubles the chances that a patient may experience surgical complications, such as nerve damage, but it also leads to a lifelong reliance on thyroid replacement therapy as well as transient or permanent hypothyroidism, which translates into low calcium levels, in 20% and 2-3% of patients, respectively,” Dr. Valderrabano said, “This is compared to only 20-30% of patients needing such treatment following a thyroid lobectomy,” he said, and the patients who undergo total thyroidectomy will then be at increased risk for osteoporosis, and added to that are concerns of likely hypoparathyroidism.4

The operation can also affect voice function by injuring one or both of the laryngeal nerves whereas the election of lobectomy will avoid the need for the radioactive iodine treatment that typically follows a thyroidectomy, he said.

“Virtually no patients who received a lobectomy had to face any of these added problems,” said Dr. Valderrabano.

Time to Address Over-diagnosis and Over-treatment of Thyroid Nodules   

When it comes to thyroid cancer, “we have an epidemic of over-diagnosis and over-treatment,” said H. Gilbert Welch, MD, PhD, professor of medicine at the Dartmouth Institute for Health Policy and Clinical Practice in Lebanon, New Hampshire, who co-authored a commentary: Saving thyroids–Overtreatment of small papillary cancers with Gerald M. Doherty, MD, surgeon in chief at Brigham and Women’s Hospital and Dana-Farber Cancer Institute and professor of surgery at Harvard Medical School in Boston, Massachusetts. 

In part, this is due to increased screening and “incidental diagnosis” such as when a thyroid neck module is noticed during an ultrasound of the carotid artery ordered for other reasons.2

But, Dr. Welch said, “although the rate of thyroid cancer has increased by three-fold since the mid 1990s, the death rate has remained remarkably stable.”

Based on the data, there is a twenty-five year risk of death due to thyroid cancer in patients with papillary thyroid cancer who were treated with surgery—either thyroidectomy or lobectomy—which  is extremely low (2%) and that rate isn’t affected by the choice of procedure, he said.

Over-diagnosis of thyroid Cancer Endemic in Younger Women

“The median age of thyroid cancer in women is currently lower than breast cancer,” said Dr. Welch. “Yet, women are three times more likely than men to get a diagnosis of thyroid cancer while equally likely to die from it.” The reason is simple:  Women are at a higher risk of over-diagnosis because they tend to see doctors more often than men.”

“The point of our paper is that if you’re going to do something about thyroid cancer you should be doing a lobectomy, not a total thyroidectomy,” Dr. Welch told EndocrineWeb. “There’s not any advantage to doing the more complete surgical procedure, in most cases, and there are real reasons not to do it given the associated risks.”

Despite this recommendation “the rate of total thyroidectomy is accelerating faster than lobectomy with about 80 percent of patients who have surgery for localized papillary cancer undergoing a total thyroidectomy,“ he said.

“It’s a combination of ignorance, true belief, preference for completeness, and financial incentive,” said Dr. Welch.

He further noted:

  • Historically, physicians have tended to believe more surgery is better.
  • Providers are simply not aware of emerging data that lobectomy is an equivalent procedure for small papillary thyroid cancers.
  • Surgeons who does not do many thyroid surgeries annually may not be sufficiently up-to-date with the current guidelines for thyroid treatments.
  • While surgeons are paid basically the same rate for a surgery be it thyroidectomy or lobectomy, a total thyroidectomy paves the way for radioactive iodine treatment that may be an important source of income for endocrinologists and nuclear medicine specialists.

Embracing Active Surveillance as Firstline Treatment for Small Thyroid Tumors

One answer to the problem of overtreatment, said Dr. Welch, might be to avoid looking so intensely for early thyroid cancers.

“We’ve been taught that the best way to treat cancer is the find it early, but ironically one of the solutions for overdiagnosis of thyroid cancer is not to look so hard for these types of small cancers,” he said.  

“That said, the next best level of patient care is to counter over-diagnosis—as is common in both prostate and thyroid cancers—to provide active surveillance for these patients, which means to watch the tumors to see if they are growing, Dr. Welch said, “It’s now pretty standard practice for prostate cancer management and can now be offered more often for small papillary thyroid cancers.”

 “I think that would be a step in the right direction,” Dr. Welch said.

No financial conflicts were indicated for either physician.

Continue Reading:
Clinical Tool Introduces Active Surveillance for Papillary Thyroid Cancer
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