Very few people can point to where their thyroids are, let alone explain what the organ does – and most probably wouldn’t suspect that their recent cough and scratchy voice could be the symptoms of something much worse than a summer cold. While thyroid cancer has a fairly favorable survival rate, about 36,000 people worldwide die of this condition each year – and the sooner it’s caught, the less likely it is to be fatal.
Slide your finger from your chin down to your Adam’s apple, and stop when you find the next ridge in your throat. This is the cricoid cartilage, and it’s the home of your thyroid gland. The thyroid produces hormones that help to regulate the body’s metabolism and to control the amount of calcium in the bloodstream.
Because the thyroid performs multiple functions, it is made up of multiple types of cells. Although any type of thyroid cancer starts as one or more small nodules in the gland, each of the four main cell groups will give rise to a slightly different form of thyroid cancer.
The type of thyroid cancer with the best prognosis is papillary carcinoma; this is also the most frequent type to appear, especially in children with thyroid cancer and in young to middle-aged women. While papillary carcinoma is fairly likely to spread to lymph nodes in the vicinity, it rarely invades blood vessels to make its way to the rest of the body.
Follicular carcinoma makes up about 10% of thyroid cancer cases, and is most likely to appear in older women. This type of cancer originates in the cells responsible for the thyroid’s production of metabolism-controlling hormones, and while the prognosis isn’t as good as for papillary carcinoma, 85% follicular carcinoma patients are able to survive ten years or more following their diagnosis.
The third most common type of thyroid cancer is medullary thyroid carcinoma, or MTC. The cells affected by MTC produce the hormone calcitonin, which helps to regulate the body’s blood calcium supply. Because of this, other symptoms than the characteristic thyroid nodules may appear as the body’s calcium supply runs out. Many patients find themselves experiencing diarrhea and extensive itching as their calcitonin supply bottoms out.
Finally, the least common but most deadly of the four main types of thyroid cancer is Hurthle cell carcinoma. This is a specific type of follicular cell carcinoma that involves a much higher risk of the cancer spreading to other organs, and its more aggressive nature warrants a more aggressive treatment plan. While there are other types of thyroid cancer than these four, they are much more rare, and comprise only about 1% of cases.
Diagnosis & Treatment
If thyroid nodules or other suspicious symptoms have been noted, an ultrasound scan can be used to visualize the thyroid and detect any lesions present. Such a scan may be done in combination with measurements of blood hormone levels in order to rule out other glandular diseases.
Once the presence of cancer has been confirmed, surgery is often part of the treatment plan. If the cancer has not spread outside the thyroid, the surgeon may try to remove the cancer while leaving unaffected parts of thyroid itself in place. Otherwise, the entire gland may need to be removed.In order to ensure that all cancerous cells are wiped out, radiation therapy may be given following the surgery.
Because two of the important hormones produced by the thyroid contain iodine, the body’s iodine tends to concentrate in the gland. This means that radioactive iodine can be used to localize treatment to this region alone, and prevent the radiation from damaging other parts of the body. (Treatment of this kind is especially effective in the case of follicular carcinoma, because this is the type of cell where the iodine is used to build those specific hormones.) Chemotherapy may be a treatment of last resort if both surgery and radiotherapy fail to control the spread of the disease.
While the prognosis for most forms of thyroid cancer is very positive compared to many other types of cancer, complications may arise either from the disease itself or from the treatment. As nodules increase in size, they can damage other tissues in the area (such as the voice-box and local nerves), causing voice changes. Post-surgical scarring can also do some damage to the vocal cords.
Another complication, especially in the case where the entire thyroid is removed, is the loss of hormone production. Usually the patient can achieve hormone levels close to normal by taking replacements orally in pill form, so that she experiences a similar quality of life to what she had before diagnosis.