ENDO2020 Presentations: International Thyroid Research

New studies from Japan and Italy showed surprising findings

With Lori J. Wirth MD and Roberto Cesareo MD

Both international thyroid studies presented at ENDO2020 had unexpected conclusions.

Radiofrequency ablation found superior to laser ablation 

An Italian trial pitting two kinds of ablation therapy against each other for the treatment of benign thyroid nodules had a distinctly positive outcome. The results were published shortly after being delivered by Roberto Cesareo MD, the director of metabolic disease at S.M. Goretti Hospital in Latina, Italy.

The open-label randomized study looked at the differences among participants in target nodule volume at 6 months after treatment, and how many in each group had nodule reduction of more than 50%. A secondary endpoint, never before studied, was whether the histopathology of a nodule could predict the response to treatment. Sixty patients were enrolled.

Patients were assessed for thyroid stimulating hormone, free thyroxin, and calsitonin levels, as well as TgAb and TPOAb. Baseline and 6-month measurements were taken. Researchers asked patients to rate their compression symptoms and cosmetic concerns – the former on a 10 point scale and the latter on a 4 point scale. Mean levels at the start of treatment were 4.5 for symptoms and 3.4 for cosmetic concerns.

Investigators used ultrasound to calculate baseline volume, and core needle biopsies to determine histological architecture of the nodules. Laryngoscopy determined the impact on vocal cord mobility.

Currently, radiofrequency ablation is considered to have the same efficacy as alcoholizaiton treatment with ethanol, Cesareo says, but “the literature provides poor and week evidence” that it is a superior treatment option. It is, however, a cheaper option, and has represented the gold standard of treatment thus far. Radioiodine treatment and surgery are used for hot thyroid nodules and are considered the gold standard for those. Recently, Cesareo says, there have been both retrospective and prospective studies that support ablation therapy for such autonomously functioning thyroid nodules.

In this study, radiofrequency ablation was found to be superior to laser ablation, although in nodules with higher cellular component, laser ablation seems to work better. Both treatments were well tolerated and effective at reducing nodule volume. The radiofrequency patients had a mean reduction in volume of 64.3%, compared to 53.2% for the laser ablation group. Both groups saw a reduction in symptoms and cosmetic concerns that were not significantly different for either treatment. A mean reduction in compression symptoms of 3 points vs. 2.8 points was found for radiofrequency versus laser, and a mean reduction of 1.9 points vs. 2 points in cosmetic symptoms. Neither group showed a change in thyroid stimulating hormone levels after the procedures. More than three quarters of the patients experienced at least 50% reduction in nodule volume.

“The need of re-treating your subject is quite similar between the two techniques,” Cesareo tells Endocrine Web. There may be a cost differential, however. “Using laser ablation, the larger the nodule volume, the higher the number of fibres you need. For the radiofrequency ablation, the cost would not change with the size because you use the same needle," says Cesareo.

What makes this study different is that it is a single center, single treatment, randomized, controlled trial, and the first one aimed at determining which of the two ablation treatments is better. It also included just a single type of nodule: solid or predominantly solid. Previous studies haven’t been randomized, included retreatments, nor included different types of nodules.

The team is still looking at data with an eye to publishing the 1-year figures in the near future. For now, physicians shouldn’t change what they do with patients who have these nodules. “Our findings point out that radiofrequency ablation is more effective than laser ablation in reducing thyroid nodules volume, and that both procedures are clinically effective and safe.”

Research presented by the International Thyroid Oncology Group

A group of international researchers from the International Thyroid Oncology Group looked at the use of lenvatinib as part of a phase 2 trial. ATC is aggressive and has a 5-year survival rate of just 7%. Existing treatments have been ineffective, with their efficacy usually lasting less than 6 months, says Lori J. Wirth MD, the Elizabeth and Michael Ruane Chair of Endocrine Oncology and medical director of head and neck cancers at Massachusetts General Hospital.

Lenvatinib had been more successful, with 24% response rate, in a small study in Japan. This one involved a broader population with the disease. The study authors wanted to see a response in more than 15% of the 34 patients at the interim point of 6 weeks or the study would be halted. As only 3 patients achieved a reduction of more than 30% in the target lesion, they decided to end it.

“Sure, we were disappointed that we did not see a stronger signal with lenvatinib in ATC,” Wirth tells Endocrine Web. “That said, I think this study will provide very useful information going forward. There are currently combination lenvatinib/immunotherapy single arm trials underway. The results of our study will provide an important benchmark for these new trials.”

She notes that while the drug has some antitumor activity as a single drug, it is not enough. "We are hoping that combining it with immunotherapy or other agents will result in better activity,” says Wirth. Already, the combination of lenvatinib and pembrolizumab is approved for other tumors in other cancers.

Though somewhat surprising, the results remain important. “I think negative results should be made public first and foremost so that we can learn from therm,” Wirth says. “Did the negative data result from a therapy that was not effective as hoped, or was it because of a trial design that was less that optimal? It’s challenging to do clinical trials in ATC. The lenvatinib study showed that a well-designed trial can be done, and will be a foundation for futher study."

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