Thyroid cancer might be one of the most common types of cancer for all people, but is it more common in one gender?
The answer? Yes. Thyroid disorders, cancer included, are more common in women. A staggering 80% of women are affected by thyroid nodules, but only five to 15% of those turn out to be cancer.
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Glenda Callender, MD, is medical director of endocrine surgery for Hartford HealthCare’s Fairfield Region and an endocrine surgical oncologist at St. Vincent’s Medical Center in Bridgeport, where she treats a many women for thyroid issues.
Often, she said, women will live their whole lives with small papillary thyroid cancers without being aware of it. Autopsy studies of individuals who did not die of thyroid cancer found between 20 and 30% of them had such tumors at the time of their death.
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What are the types of thyroid cancer?
Different types of thyroid cancer include:
- Differentiated thyroid cancers. This broad category includes types of thyroid cancer that start in the follicular cells, which produce and store thyroid hormones. Papillary thyroid cancer and follicular thyroid cancer are the two types of differentiated thyroid cancer.
- Papillary thyroid cancer. This is the most common type of thyroid cancer. It most often affects people ages 30 to 50. Most papillary thyroid cancers are small and respond well to treatment, even if the cancer cells spread to the lymph nodes in the neck. A small portion of papillary thyroid cancers are aggressive and may grow to involve structures in the neck or spread to other areas of the body.
- Follicular thyroid cancer. This less common type of thyroid cancer usually affects people older than 50. Follicular thyroid cancer most often spreads to the lungs and bones.
- Hurthle cell thyroid cancer. Hurthle cell thyroid cancers are a subtype of follicular thyroid cancer. They can be more aggressive and can grow to involve structures in the neck, or spread to other parts of the body.
- Poorly differentiated thyroid cancer. This rare type of thyroid cancer is more aggressive than differentiated thyroid cancers and often doesn’t respond to the usual treatments.
- Anaplastic thyroid cancer. This very rare type of thyroid cancer, which is found mostly in people over 60, grows quickly and can be difficult to treat. However, treatments can help slow the progression of the disease.
- Medullary thyroid cancer. This rare type of thyroid cancer begins in thyroid cells called C cells, which produce the hormone calcitonin. Some medullary thyroid cancers are genetic.
Callender said she will find tiny papillary thyroid cancers in women when she removes their thyroid because of Graves disease or other benign thyroid issues about 30% of the time.
“Most larger thyroid cancers these days are also incidental findings,” she said. A patient could be having a CT scan or ultrasound for an unrelated issue in the same area of the body (such as a carotid duplex), and nodules are discovered in the thyroid. “That’s how the vast majority of thyroid cancers today are diagnosed – before there are any actual advanced symptoms.”
It’s more common to find thyroid cancer in women in part “because women tend to go to the doctor more. Plus, everything related to the thyroid is more common in women than in men.”
Concerns about overtreatment
One issue that can stem from the more frequent discovery of small papillary thyroid cancers is that too much treatment might be prescribed for a cancer that more often than not isn’t fatal.
Previous protocol, Callender said, was that “any time you had a diagnosis of thyroid cancer, you removed the whole thyroid.” But in post World War II Japan, large studies were done on thyroid cancer patients that showed that although huge numbers of people had these micro-carcinomas, it wasn’t necessary to remove the whole thyroid as treatment. A group of patients was followed with close surveillance instead of surgery.
“In two-thirds of them, the thyroid cancers were tiny when they were discovered and they stayed tiny,” she said. “In the one-third that did have something change or grow, they had the standard surgery.” No one in either group died of thyroid cancer.
Treatment options available to me
Callender said based on all the studies done abroad and in the U.S., patients with small thyroid cancers are typically offered:
- Surveillance, in which the cancers are checked regularly for any changes or growth.
- Thyroid lobectomy, in which one lobe (one half) of the thyroid is removed.
- Total thyroidectomy, in which the entire thyroid is removed, followed by thyroid hormone treatment for life.