Will Thyroid Cancer Come Back?

Thyroid cancer is sometimes described as a "good" cancer because the prognosis is very good for most patients, meaning that you are unlikely to die from the thyroid cancer. However, there is no such thing as a "good" cancer. One of the reasons that cancer is scary is because it can come back, even years after you have completed treatment. Let's talk about thyroid cancer coming back and what you can do to prevent thyroid cancer from coming back.

First, when thyroid cancer comes back, it is called a recurrence. Recurrence is not common, but some studies have found that thyroid cancer can come back as often as 28% of the time after the initial treatment. That means that as many as one in four people who are treated for thyroid cancer will need more treatment in the future. The American Thyroid Association classifies people on their risk of recurrence into 3 categories based on labs after surgery, type of cancer that the patient had, and what the ultrasound after surgery demonstrates (low risk, intermediate risk, and high risk are the 3 categories).

Second, even when thyroid cancer does come back, the prognosis remains excellent. In North America, most thyroid cancers are caught very early. Because we catch these cancers so early, we are able to minimize the treatment and we try to do as little initial treatment as is safely possible. This does allow for more recurrence (see below), but it does minimize the complications of surgery or other treatments. It also means that treatment for any of these recurrences is less complicated and also less likely to have problems. Overall, this is great news for patients because the second round of treatment is also often simple.

Third, thyroid cancer recurrence rates depend quite a bit on the initial stage of your cancer. Smaller cancers and cancers that have not started to spread have a much better chance of being treated completely with the first round of treatment. FOr that reason, sometimes doctors will talk about earlier treatment of small cancers and nodules that could become cancer- because we know that patients do better in the long run if they have treatment early.

Fourth, removing all of your thyroid so that you can have radioactive iodine doesn't seem to help with your long-term survival of a cancer, but it might affect your risk of a recurrence. This makes intuitive sense: thyroid cancer can spread to the other side of your thyroid. Treating one side (just a thyroid lobectomy) is almost always all the surgery and treatment that a person will need for most thyroid cancers. BUT, if the other side of the thyroid is still present, then there is a risk that the cancer will come back on the other side. You decrease this risk by removing the entire thyroid (also known as a total thyroidectomy). Despite this small benefit, the risks of a total thyroidectomy are greater, and so it's not the right choice for most patients with a small thyroid cancer.

Fifth, no matter where thyroid cancer spreads to or where it comes back, it will always be thyroid cancer. This means that, even in the horrible situation in which it spreads to your lungs or even your brain, it will always be thyroid cancer in your lungs or in your brain. That's usually really good news, because thyroid cancer usually grows more slowly than lung or brain cancer, and so the prognosis is usually better even in those scary situations. It also means that we can continue to use treatments such as radioactive iodine and targeted thyroid therapies against these cancers. And those treatments tend to work quite well even for patients with advanced cancer recurrences.

Finally, the best thing that you can do to prevent cancer from coming back is having the right surgery and the right surgeon involved the first time. Why? Because an experienced surgeon is more likely to do the most complete surgery on each individual side, while also having a lower complication rate. They are also more likely to be able to discuss all of the other options, such as radiofrequency ablation or "scarless" thyroid surgery. A new program from the American Board of Surgery can help you to find a surgeon who has focused their practice on thyroid and parathyroid surgery- and ideally would help you to have the best outcome. These surgeons are known as Focused Practice Designation (FPD) surgeons.