The thyroid is very sensitive to subtle assaults. That one sentence explains most of what follows, and it is why the first thing I ask anyone with a thyroid nodule is not about the nodule. It is about where they have lived and what they have done for work, because radiation exposure is the most common identifiable cause of papillary thyroid cancer.
Key takeaways
- Radiation therapy to the head, neck or chest is the most common identifiable cause of papillary thyroid cancer.
- Populations downwind of nuclear production or test sites, in New Mexico, Nevada, eastern Washington around Hanford, Chernobyl and Fukushima, show clusters of thyroid cancer and deserve careful screening for life.
- Uranium mining and nuclear waste handling count as occupational radiation exposure, and anyone with that history should be screened.
- With a known gene mutation that raises thyroid cancer risk, the first step is a thyroid ultrasound, and a RET oncogene finding triggers screening for other family members.
- After removal of half the thyroid, function is checked at about thirty days, and many people never need thyroid hormone.
Does radiation exposure increase your thyroid cancer risk?
Yes. Radiation exposure is the most common identifiable cause of papillary thyroid cancer. The clearest case is radiation therapy to the head, neck or chest for some other reason, which happens to expose the thyroid as well. That is how I got mine. I had chest radiation as a child, and ten years later, surprise! I had thyroid cancer.
Environmental and occupational exposure matters too. Around every site where nuclear material was made, tested or released, there are cluster effects for thyroid cancer and other thyroid conditions. Those populations need to be screened carefully, and the index of suspicion for ongoing problems stays high for life.
If this is the question you came in with, it is the one we answer in your first hour here. New patients are seen within two weeks and you do not need a referral. Call or text (817) 380-4880.
Who are the “Downwinders”?
The “Downwinders” are the people who lived downwind of the first atomic bomb test in New Mexico in July 1945 and received the fallout without warning. The name came up when someone wrote to say they had just been diagnosed with chronic fibrous thyroiditis, and that they were born in New Mexico during the period of highest radiation fallout.
I did my fellowship in New Mexico, and we were taught very carefully that a thyroid history has to include two questions. Have you ever lived anywhere you were exposed to radiation? Have you ever worked a job that exposed you to radiation? In New Mexico, some people work in uranium mines. And there are the Downwinders.
In July 1945 the first atomic bomb was tested near White Sands, in what the people running the test assumed was the middle of nowhere. It was not nowhere. There were small towns and native communities living in that desert, and none of them were warned. They woke up to a blinding light.
There was a small summer camp not far from Alamogordo. The girls there were woken in their cabins by the flash. Later that day they went outside and it was snowing. Black snow. They caught it, and it was warm. The flakes were hot. They did not know what it was, so they played in it all day and swam in the water. None of them lived to see their thirtieth birthday.
That is the downwind population. A similar pattern is seen around the Hanford site in eastern Washington, where enriched uranium and plutonium were produced and some of the waste reached the groundwater. It is the same pattern across the eastern borders of Europe after Chernobyl, and in Japan after Fukushima, where the fallout even crossed the Pacific and was detectable on the west coast of the United States. Some parts of the United States, like Michigan, have a lot of background environmental radiation, such as from radon.
Which places and jobs raise thyroid cancer risk?
Thyroid cancer risk rises anywhere with a history of nuclear production or testing, and with any job involving radiation exposure. New Mexico and Nevada, where atomic testing was done. Eastern Washington, around Hanford. Eastern Europe in the 1980s, downwind of Chernobyl. Japan after Fukushima. Michigan, where the geology produces a lot of radon. Uranium mining. Nuclear waste handling.
Three Mile Island never had a meltdown, so we are not aware of an exposure in Pennsylvania from that event.
Watch what a cardiologist wears into a heart catheterization. A lead apron, and that apron includes a thyroid shield. That is how sensitive this gland is to radiation.
So when I take a history, I ask where you have lived. Have you always been in Texas? Where else? What did you do for work? Anyone with occupational or environmental radiation exposure should be carefully assessed by an endocrinologist, and someone with chronic fibrous thyroiditis after that kind of exposure I would ultrasound at least once a year, looking for nodules with unusual features.
I have a gene mutation that raises thyroid cancer risk. What should I ask?
Knowing you carry a gene mutation that raises thyroid cancer risk is genuinely useful, because it changes what we do. The first thing that should happen is a thyroid ultrasound. If the ultrasound shows nodules, our ears are up. We are paying close attention, and we are not going to miss or delay anything.
You may want to be followed by endocrinology from the beginning rather than waiting for something to be found.
Does thyroid cancer run in families?
Some types of thyroid cancer do run in families. There are inherited conditions, the multiple endocrine neoplasias, with family patterns for very specific thyroid cancers. Papillary thyroid cancer, the common one, does not tend to follow that pattern. Family history is still one of the standard questions I ask anyone with nodules.
If someone carries a particular genetic finding such as the RET oncogene, we have a plan in place to notify other family members, because they probably need screening too. The questions I ask: any thyroid cancer in the family? Who, when, how many, what kind? The answers change surveillance and sometimes change intervention.
Should a 70 year old treat papillary thyroid cancer or leave it?
Seventy is a little young to default to no treatment for papillary thyroid cancer. Generally it is slow growing and indolent, and in people in their late seventies and eighties we may not biopsy or treat it, because it is unlikely to affect their health span or lifespan and not many surgeons want to operate at that age.
But what matters is the patient, not the number. If you have several serious chronic conditions, you have bigger problems than a papillary thyroid cancer. If you are spry, active and living well at 70, then you should be treated, because you may live to 90 or 100 and we do not want this to be the thing that impairs that.
Can you live with half a thyroid and no medication?
Yes, a fair number of people do. If half the thyroid is removed, we do not automatically start thyroid hormone. We wait to see whether the remaining half picks up the slack. At about thirty days after surgery we check function. If it is dwindling, you may need something. If it is holding, you move on with your life.
The body tells us, and we adapt.
Where this leaves you
Radiation therapy to the head, neck or chest is the most common identifiable cause of papillary thyroid cancer. Living downwind of a test site, near Hanford, in Michigan’s radon environment, or working in a uranium mine puts you in a population that needs careful, lifelong screening. None of that is on your ultrasound report. It is in your history, and somebody has to ask for it.
See your own numbers, not a guess. If you have lived or worked near any of the places above, your history changes the plan, and it only changes it if someone asks. Bring it to a consultation. An hour, $400, first follow up included, in person in Mansfield or by video. To book your consultation, call or text (817) 380-4880.
Frequently asked questions
Does radiation exposure increase thyroid cancer risk?
Yes. Radiation therapy to the head, neck or chest is the most common identifiable cause of papillary thyroid cancer, and populations near nuclear production or test sites show clusters of thyroid cancer and thyroid disease.
Who are the Downwinders?
People who lived downwind of the 1945 atomic test in New Mexico and received fallout without warning. Similar populations exist around Hanford, Chernobyl and Fukushima. They need careful, lifelong thyroid screening.
Which jobs raise thyroid cancer risk?
Uranium mining, nuclear waste handling, and any work with occupational radiation exposure raise thyroid cancer risk. Anyone with that history should be assessed by an endocrinologist, and I ask every patient with a nodule where they have lived and what they have done for work.
Does thyroid cancer run in families?
Some types do, through inherited conditions such as the multiple endocrine neoplasias and findings such as the RET oncogene. Papillary thyroid cancer usually does not. Family history still changes how closely we watch you.
Should papillary thyroid cancer be treated at 70?
Usually yes, if the patient is otherwise well. In the late seventies and eighties we often leave it, because it is slow growing and unlikely to affect lifespan. At 70 the decision depends on overall health, not the birthday.
Can you live without thyroid medication after a partial thyroidectomy?
Yes, many people do. After removal of half the thyroid, we do not automatically start thyroid hormone. Function is checked about thirty days after surgery. If the remaining half keeps up, no medication is needed. If it is dwindling, you may need something.
Related reading
- TI-RADS score explained: what your thyroid nodule report actually says
- Atypia on a thyroid biopsy: what the result means
- Thyroidectomy recovery: what to expect after thyroid surgery
Dr. Lindsey M. VanDyke, DO, FACOI, FEAA, is dual board certified in internal medicine and in endocrinology, diabetes and metabolism. She founded the Advanced Institute for Diabetes and Endocrinology in Mansfield, Texas, where new patients are typically seen within two weeks. She completed her endocrinology fellowship in New Mexico and is herself a thyroid cancer survivor.
In person in Mansfield, or by video in Texas, Oklahoma, New Mexico, Colorado, California, Oregon and Washington.
Book your consultation. Call or text (817) 380-4880.