The thyroid gland is a large endocrine gland found in the neck below the thyroid cartilage that forms the adams apple. The gland controls how rapidly the body uses energy, how the body responds to hormones and it makes proteins. The thyroid gland does these things by producing thyroid hormones including triiodothyronine (T3) and tetraiodothyronine (T4). These hormones affect the growth rate and function of many parts of the body and manipulate the rate of metabolism within the body.
Symptoms of Thyroid Cancer
The technical description for Thyroid cancer is a malignat thyroid neoplasm with comes from parafollicular or follicular cells. Typically the thyroid cancer is often first detected as a nodule in the thyroid which can found by an examination from your doctor. Nodules are somewhat commonplace though, with 95% of nodules not malignant. Other early symptoms include an enlarged lymph node, pain in the neck and possibly a change in voice.
Symptoms of hyperthyroidism can sometimes be associated with a large metastatic tumor. Nodules in the thyroid are more serious for younger patients because they are less common in people below 20. If a young person has nodules it is far more likely to be malignant.
Diagnosis of Thyroid Cancer
After a general practitioner locates a thyroid nodule during a physical exam, the patient is usually forwarded to an endocrinologist or thyroidologist who normally perform an ultrasound to confirm the presence of the nodule. They then assess the condition of the thyroid and do tests on the strength of thyroid hormones and anti-thyroid antibodies. That helps them determine if a thyroid disease is present and has caused the nodule.
To finally determine if cancer is present, a fine needle aspiration cytology test is performed.
Thyroid Cancer Classification
Thyroid cancer is classified into the following categories:
- Papillary thyroid cancer – The most common form of thyroid cancer usually found in young females. Makes up about 75%-80% of cases, it has a very good prognosis
- Follicular thyroid cancer – makes up 10% to 20% of cases
- Medullary thyroid cancer – makes up 5% to 8% of cases
- Poorly differentiated thyroid cancer
- Anaplastic thyroid cancer – makes up less than 5%
The follicular and papillary types of thyroid cancer have a much better prognosis than medullary and undifferentiated thyroid cancer types.
Thyroid Cancer Treatment
Thyroid cancer is similar to prostate cancer in that it is very common in older adults, is slow growing and often doesn’t even require treatment. Slow growing thyroid cancer may not even produce any symptoms, so the patient isn’t aware of any problems and can pass away from another illness before the thyroid cancer becomes a concern. For this reason, a slow growing thyroid cancer is rarely treated.
For faster growing thyroid cancer there are a number of options. Surgery is sometimes used with the thyroidectomy and lobectomy procedures being two of the most common approaches.
Radioactive Iodine-131 is often used post-surgery to treat patients who have papillary or follicular thyroid cancer. It is used for ablation of residual thyroid tissue after the surgical work has been performed. Some types of thyroid cancer, including medullary, anaplastic, and many Hurthle cell cancers do not benefit from radioactive iodine-131 treatment.
Occasionally external radiation is also used to help relieve pain or when the cancer is unable to be removed by surgery.
Some new drugs including Sorafenib and Sunitinib have shown promising results for the treatment of thyroid cancer.
Prognosis for Thyroid Cancer
For the most common form of thyroid cancer, papillary, the prognosis is very good with an overall 5 year survival rate of around 97%. There are 4 stages of development of thyroid cancer and if caught at stage I or stage II, papillary thyroid cancer has a 100% 5 year survival rate. At stage III that shortens to 93% and at stage IV that becomes 51%. There is currently a greater trend towards early detection of thyroid cancer, which has led to a boost in the survival rates.
The follicular and medullary have similar 5 year survival rates, however stage IV medullary thyroid cancer patients have a much lower 5 year survival rate ay 28%.
Anaplastic thyroid cancer is always stage 4 and has a poor 5 year survival rate at 7%. This relatively rare form of thyroid cancer is very aggressive and has shown resistance to the traditional forms of thyroid cancer treatment. Anaplastic thyroid cancer usually spreads into the surrounding tissue rapidly, also explaining the poor survival rate.
Thyroid cancer is much less common in men than it is in women, with women being three times more likely to be afflicted.