Treating Thyroid Nodules and Thyroid Cancers
Dr. Insoo Suh, an endocrine surgeon at UCSF Medical Center, talks about new developments in the treatment and management of thyroid nodules and thyroid cancer.
Thyroid cancer is one of the most common cancers. Why is the incidence rising?
The main reason is that imaging studies are both improving in resolution and being used much more frequently by clinicians. Doctors are screening and finding thyroid nodules more now when people get imaged for other medical problems.
Recently, the question of over-diagnosis and over-treatment of disease has come more into the forefront — the idea that maybe it's not always a great idea to find the smallest things that may otherwise not affect a person's life in the long run.
How is thyroid cancer usually treated?
The classic answer is to have surgery to remove the entire thyroid, and then potentially be treated with radioactive iodine. But that is no longer the right answer for everyone, especially in patients with low-risk tumors.
Sometimes it is reasonable to remove only half of the thyroid and hold off on radioactive iodine. And it may even be reasonable to forego treating the lowest-risk tumors at all and instead provide active surveillance to make sure they don't grow or spread with time.
But if you're a young person just diagnosed with a small, low-risk thyroid cancer, is the right answer to subject you to an endless regimen of surveillance for the rest of your life? Those types of nuanced questions and discussions are what we see much more often now.
What kinds of thyroid cancers can be safely monitored without surgery?
Basically, only a select group of low-risk papillary thyroid cancers less than 1 centimeter in size. It has to be the only abnormality in the thyroid gland. It can't be located in certain high-risk areas, such near the back of the thyroid, where an important nerve called the recurrent laryngeal nerve resides.
There can't be other features that would classify the cancer as high-risk, such as a family history of thyroid cancer or a significant history of radiation exposure.
Only a select group of people fit into that category, but for that group of folks, it is actually a very valid way of managing thyroid cancer, again provided that they are followed diligently.
Can molecular testing clarify whether cancer is present when a thyroid biopsy shows uncertain results?
In the next 10 to 15 years, I believe molecular testing of thyroid nodules is going to fundamentally alter the way we approach these diseases. However, at the moment there's much room for improvement.
There are basically three main providers of these molecular tests on the market today, and none of them are 100-percent foolproof. In addition, often patients will have these tests when they're not really indicated, which can potentially muddy the clinical picture.
In the longer term, molecular testing is going to be more accurate and useful in a broader group of patients. Right now, it's of real benefit in only a select number of cases, certainly fewer than the number of times it is actually used.
How are benign thyroid nodules treated?
Whether or not a benign nodule is functioning and making thyroid hormone can determine which way you go. If it's functioning, surgery is a valid method to treat the hyperthyroidism caused by the nodule.
A benign, nonfunctioning nodule can be safely managed by observation over time. Endocrinologists or primary care providers usually coordinate this. You want a surveillance program that consists of an ultrasound and some blood tests to make sure the thyroid function doesn't worsen.
If the nodule tends to grow or develop any suspicious characteristics, those would be indications to get a repeat biopsy or consider surgical removal.
Are there any new endocrine surgical techniques on the horizon?
Some of the stuff that's really exciting to me is an increase in technologies to better identify delicate structures in the neck that we're normally trying to protect during surgery. For example, the recurrent laryngeal nerve is one of the structures most at risk for damage after thyroid or parathyroid surgery.
Is that the nerve that, if damaged, can make a person lose her voice?
Yes, it can cause a person's voice to go hoarse because the vocal cord that the nerve controls can get weak or become paralyzed. The nerve is intimately associated with the back of the thyroid and can be very difficult to identify or preserve.
The other main structures that are at risk during a thyroidectomy are the parathyroids, which are tiny little glands next to the thyroid that control calcium in your body.
There are several exciting technologies meant to try to visualize these structures better during surgery. They involve a variety of different camera techniques, detection of different wavelengths outside the typical visible spectrum, things like that.
What does visualization using different wavelengths pick up?
If you switch on a camera with light at a certain wavelength, you can potentially identify parathyroid tissue without having anything else light up.
There is also a wide variety of fluorescent tracers that can be injected into the bloodstream that light up different structures at different intensities, which could for example help with detection of the recurrent laryngeal or other nerves. I don't think these technologies are quite ready for prime time yet even in the next few years, but they are certainly stuff to keep an eye out for.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.
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