Thyroid cancer, the two most common types of which are generally among the most treatable cancers, is on the rise. Incidences of thyroid cancer in the United States and Europe have doubled in the last ten years. If incidence of the disease continues to rise at the present rate, thyroid cancer could become one of the top three cancers in the country.
Why is thyroid cancer on the rise? There is no single clear answer to that question but there are several theories. While some thyroid cancers are related to heredity, the majority are related to mutations in one or more genes controlling the growth of thyroid cells. The reasons for these mutations, and how they relate to the severity of thyroid cancer, is the subject of current research. Until we have better information, I think it is advisable to simply keep a watchful eye out for thyroid cancer.
Types of Thyroid Cancer
Thyroid cancer originates in the thyroid gland, which is located inside the front of your lower neck. The thyroid gland produces hormones and is responsible for regulating the way your body uses energy. A properly functioning thyroid gland is important to ensuring that your body works normally.
There are four types of thyroid cancer: papillary, follicular, anaplastic and medullary. The two most common types are papillary and follicular. The good news about papillary and follicular thyroid cancer is that they are both very treatable and have excellent survival statistics. Approximately 85% of all thyroid cancer diagnoses will be papillary or follicular. Within that group, approximately 60% of occurrences are papillary and about 25% are follicular. Anaplastic and medullary are rarer and have less postive long-term prognoses. Papillary and follicular thryoid cancer, however, respond very well to treatment and have a 90% survival rate at ten years.
Causes, Risk Factors and Symptoms of Thyroid Cancer
Thyroid cancer can occur at any age and it is not clear what causes it. There are some risk factors, however. There is a higher risk of developing thyroid cancer starting in your 20‘s through your 60‘s and 70‘s. People who underwent radiation therapy to the neck, especially as children, are at higher risk for developing thyroid cancer. So are people who were exposed to radiation during a nuclear disaster. People with a family history of thyroid cancer may be at higher risk, as well.
There are a number of symptoms of thyroid cancer that include:
- Swallowing difficulty
- Englarged thryoid gland
- Lump (or nodule) on the neck, that is sometimes visible
Lumps in the thyroid are common. Approximately 50% of people will develop a lump in their thyroid at some point in their lifetime. When it reaches a certain size, it becomes visible and can be seen moving up and down when you swallow.
It is important to note that the vast majority of these lumps are benign. However, if you have developed a visible lump or if your doctor has felt a lump in your neck during a regular general check-up, you may be advised to investigate further to confirm that it is, in fact, benign.
Diagnosis and Treatment
If a lump has been detected on your thryoid, there is a standard diagnostic process in place that will likely begin with an ultrasound to determine exactly its location and size. From there, your doctor will likely recommend a biopsy of the lump to determine whether it is benign or malignant. During a biopsy, you receive a local anesthetic and then a small needle is inserted into the lump to withdraw some cells. Those cells are then studied under a microscope and provide some very good information.
If the biopsy is benign, there is about a 95% chance that no cancer is present. If the cells are “very suspicious” for cancer, in those cases, papillary cancer is typically present. In some cases, the results are indeterminate - meaning there are more questionable cells than would be present if the lump was clearly benign. In these cases, removing the part of the thyroid containing the lump is usually necessary to determine if it is benign or malignant.
As I stated at the beginning of this article, thyroid cancer is one of the most treatable forms of cancer with very good results. That’s very important to remember, especially in light of the increased number of cancers we are seeing.
Surgery is generally the first line of treatment for papilary and follicular thyroid cancer. Typically, the entire thryoid gland is removed. If lymph nodes surrounding the thyroid gland are affected, they will be removed as well. If the affected lymph nodes are not involved with cancer, they may be left in place so as to avoid complications that may arise from removing them. For instance, it is possible to damage the parathyroid gland, which affects the body’s ability to absorb calcium. Additionally, it is possible to damage two nerves that run behind the thyroid that control the vocal cords. Both of these complications are very uncommon with an experienced surgeon.
In addition to surgically removing the thryoid, radioactive iodine may be recommended. Using radioactive iodine helps doctors to see if the cancer has spread to other parts of the body. In some cases that merit more aggressive treatment, a higher dose of radioactive iodine may be administered to kill the cancer.
If the thryoid gland is removed, people are placed on medication that replicates the function of the thyroid. Patients who have had their thyroid removed generally do very well on the medication and take it for the rest of their lives.
The Bottom Line
My advice is simply to be watchful for some of the signs of thyroid cancer, in light of its recent rise in occurrence. Keep an eye out for changes in your neck; watch for visible lumps. Visit your doctor regularly -- during a standard check-up, your doctor will feel your neck for lumps. If you notice a lump, yourself, or believe you have some of the other symptoms, go to your doctor with your concerns. Rest assured -- if you do have a lump, it is probably benign. But it’s best to know for sure.
Michael Zdon is an MD of General Surgery at Advocate Condell Medical Center.