5 Things To Know About Thyroid Nodules

It’s common for people with thyroid and autoimmune thyroid conditions to have thyroid nodules.  It’s also common for people to be concerned about them, and to wonder whether their nodules are malignant, if there is a way to shrink nodules, etc.  While I have written a few articles in the past on this topic, I figured I’d put together an updated post that discusses five things anyone with thyroid nodules should know.

1. Many people have thyroid nodules.  As I mentioned in the opening paragraph, it is very common for people to have thyroid nodules.  One journal article mentioned that while 4 to 7% of the population have palpable thyroid nodules, ultrasonography reveals that up to 67% of the population has them (1).  Another study mentioned that up to 35% of the population have thyroid nodules show up on an ultrasound (2).  Even if we go with the lower number, 35% is quite high, as this means that roughly one third of the population has thyroid nodules.  The incidence of thyroid nodules increases as we age, and the prevalence is higher in women (2), although they are more likely to be malignant in men, especially those over 70 years of age (3).

2. Most thyroid nodules are benign.  Only around 5% of thyroid nodules that are detected through palpation are malignant (1).  But most thyroid nodules are not detected through palpation.  And for those thyroid nodules evaluated by a biopsy, the prevalence of malignancy ranges from 4% to 6.5% (4).  So while at least one third of people reading this will test positive for thyroid nodules, only a very small percent of these nodules will be malignant.

With that being said, the incidence of thyroid cancer has increased substantially in the United States over the last four decades (5), as the American Cancer Society estimated that 62,450 people in the United States were diagnosed with thyroid cancer in 2015 (6).  Most people with thyroid cancer are diagnosed with papillary thyroid cancer.  According to the American Cancer Society, both stage one and stage two papillary thyroid cancer have a 5-year relative survival rate of nearly 100%, and in stage three it’s 93% (7).  In stage four, the 5-year relative survival rate drops down to 51%.

Follicular thyroid cancer also has a near 100% 5-year relative survival rate in stage one and two, with a 71% 5-year relative survival rate in stage three, and a 50% 5-year relative survival rate in stage four (7).  Medullary thyroid cancer has a pretty good 5-year relative survival rate in stages one through three, but only a 28% survival rate in stage four.  Anaplastic thyroid cancer has a 5-year relative survival rate of only 7%, but fortunately only 1-2% of all thyroid cancers are anaplastic.

The reason why I’m talking about these statistics is to show you that while there without question is a risk of untreated thyroid cancer, the progression is much slower when compared to other cancers, and overall the 5-year relative survival rate is pretty good.  By comparison, the 5-year relative survival rate for the four most common malignancies in developed countries is 73-89% for breast cancer, 50-99% for prostate cancer, 43-63% for colorectal cancer, and only 12-18% for lung cancer (8).

If you’re wondering when a biopsy is necessary, please read an article I wrote in the past entitled “Is It Necessary To Get A Biopsy For Thyroid Nodules?”

3. A radioactive iodine uptake test won’t confirm or rule out malignant nodules.  For those are diagnosed with hyperthyroidism, a radioactive iodine uptake test is commonly recommended.  One reason is to confirm or rule out Graves’ Disease, as most people with this condition will have a high uptake of radioactive iodine, although I’ll add that testing positive for thyroid stimulating immunoglobulins is not only a better way of diagnosing Graves’ Disease, but is less invasive.

Besides trying to confirm a diagnosis of Graves’ Disease, another reason why endocrinologists will recommend this test is to detect thyroid nodules, as well as to differentiate between benign and malignant nodules.  And the way it tries to accomplish this is by looking at “hot” and “cold” nodules.  About 80 to 85% of thyroid nodules show up as being cold on the uptake test, and about 10% of these nodules are malignant (9).  Hot nodules account for only 5% of nodules, although the likelihood of these being malignant is less than 1%.  So essentially you’re hoping to see a hot nodule, but are far more likely to see a cold nodule, and 90% of these will be benign.

I’m not suggesting that the radioactive iodine uptake test has no value, but in my opinion it makes more sense to first get a thyroid ultrasound.  First of all, this is less invasive than the radioactive iodine uptake test.  Second, it can provide an accurate measurement of the size of the nodule, which isn’t the case with the uptake test.  And third, other characteristics of the nodule on an ultrasound can give an indication if it is potentially malignant, and thus warrants a biopsy.  It’s also worth mentioning that for those who don’t have health insurance, a thyroid ultrasound usually costs a lot less than a radioactive iodine uptake test.

The truth is that neither an uptake test or a thyroid ultrasound are perfect methods for confirming or ruling out malignant nodules.  But since the uptake test is more invasive and costs more, it makes sense to start with the thyroid ultrasound.

4. Problems with estrogen metabolism is a common cause of thyroid nodules.  According to the research, estrogen is a potent growth factor both for benign and malignant thyroid cells (10) (11).  Estrogen is also a factor with uterine fibroids, and one study involving 1144 participants looked at the relationship between thyroid nodules and uterine fibroids (12).  The authors concluded that uterine fibroids in women were definitely associated with the presence of thyroid nodules, and that estrogen might play a pivotal role in the occurrence of both of these.

As a result, if you have one or more thyroid nodules, doing things to support estrogen metabolism is a good idea.  One of the best ways to accomplish this is by eating plenty of cruciferous vegetables, as these help to support estrogen metabolism due to the compounds Indole-3-Carbinol and 3,3′-diindolylmethane (DIM) (13) (14).  Another option is to take DIM in supplement form.

For those women who are taking estrogen, I came across one study involving 33 women who received estrogen therapy for one year, and it did not seem to increase the growth of thyroid nodules (15).  While I can’t say that I’m a big fan of estrogen therapy, I realize that some women can benefit from taking estrogen (preferably bioidentical estrogen).

5. There are no specific herbs or supplements to shrink thyroid nodules.  Although supporting estrogen metabolism can help to shrink thyroid nodules, the truth is that this isn’t always effective.  Shrinking thyroid nodules can be challenging, but here are a few other factors to consider:

An iodine deficiency can cause thyroid nodules.  A few studies show a relationship between iodine deficiency and thyroid nodules (16) (17) (18).  Of course iodine is very controversial in the world of thyroid health, which I have discussed in past articles and blog posts.  Although many people with thyroid and autoimmune thyroid conditions don’t do well with iodine, at the same time we can’t ignore an iodine deficiency.  This doesn’t mean that everyone with thyroid nodules should supplement with iodine, but it probably would be wise for those with thyroid nodules to do a urinary iodine spot test, and if they are iodine deficient they should work with a healthcare practitioner who can help them correct this deficiency over time.

The main reason some people don’t do well with iodine, even when they have an iodine deficiency, is because they are also deficient in antioxidants.  While some doctors will recommend for their patients to take antioxidants while administering iodine supplementation simultaneously, I have found that a safer approach is to first increase the person’s antioxidant status over the course of a few months before having them supplement with iodine.  And when the person starts supplementing with iodine they should start with smaller doses.

Thyroxine may help to suppress thyroid nodules.  It is thought that levothyroxine-induced suppression of TSH secretion can shrink thyroid nodules, as it prevents the growth-promoting effect of TSH on thyroid cells (19).  Of course this would only be an option for those people with hypothyroidism and Hashimoto’s Thyroiditis, as you wouldn’t want a person with hyperthyroidism to take thyroid hormone.  I’ll also add that this treatment isn’t always effective, as a study involving 40 patients with confirmed benign nodules showed that suppressive therapy with levothyroxine didn’t decrease the size of benign nodules (20).

Ethanol ablation.  Percutaneous ethanol ablation for cystic thyroid nodules was introduced in 1989.  Yes, injecting ethanol into thyroid nodules can actually shrink thyroid nodules (21) (22).  This wouldn’t be my first option if I had thyroid nodules, but I would probably consider this procedure before surgery.  Ethanol ablation has been reported to have a success rate of 82-85% reduction after an average of two sessions in the management of thyroid cysts (23) (24).  However, it doesn’t seem to be as effective in shrinking solid thyroid nodules.

Laser thermal ablation.  This is a relatively new treatment option, and it can be effective with minimal complications (25).  In addition, while ethanol ablation seems to be more effective for shrinking cystic nodules, laser ablation can help with solid nodules.  It also seems to be less costly than other procedures.

I came across a journal article on laser therapy (26) which discussed a study involving 1531 patients who underwent laser ablation for 1534 nodules.  According to the study, 83% of the nodules were treated with a single session of laser ablation, and the average reduction in nodule volume at 12 months was 72% (26).  There were 17 complications, with 8 of them being major, although all of them recovered completely after they were treated with steroids.  So there are some risks, but of course this is also the case with the surgical removal of the thyroid gland, which is what many doctors recommend when someone has nodules.  A more recent meta-analysis from 2017 showed that percutaneous laser ablation was safe and useful in shrinking benign thyroid nodules, improving thyroid function, and relieving symptoms related to pressure (27).

While laser ablation for thyroid nodules seems promising, I’m not sure where someone would go to get this procedure done.  Not surprisingly, it doesn’t seem like there are many of practitioners who offer this type of treatment.  In addition, we need to keep in mind that this treatment doesn’t do anything to address the cause of the problem.  On the other hand, if someone takes a natural treatment approach but the thyroid nodules don’t shrink, then they might want to consider this procedure.

So hopefully you learned a few new things you didn’t already know about thyroid nodules.  Although many people have thyroid nodules, the good news is that most of these are benign.  Problems with estrogen metabolism and an iodine deficiency are common causes of thyroid nodules, and while addressing these imbalances is essential, there are other treatment options to consider.  Thyroid surgery is an option, but should be the last resort.  Other options include thyroxine therapy, ethanol ablation, and laser ablation.