What is cancer of the thyroid?
Thyroid cancer is a disease in which cancer cells are found in the thyroid gland tissues. The thyroid gland is located at the base of the throat. It comprises of two lobes- one on the left and the other one on the right. The gland is responsible for making very important hormones that help the body in its normal functioning.
Thyroid cancer is common among women than men. Patients with this type of cancer are normally between the age of 25 and 65 years. The most affected people are those who have been exposed to large quantities of radiation, or have been treated of radiation medical problems in their heads and necks, and have higher chances of getting the cancer again. This cancer type may not occur until after a period of 20 years or longer after the radiation treatment.
One should seek medical advice from a qualified doctor if there is a swelling or lump in front of the neck or any other part of the neck. A doctor will feel the patient’s thyroid and then check for lumps around the neck if there are any signs or symptoms. One may be required to undergo some blood tests or special scans to identify if the lump in the thyroid is making excessive hormones. The doctor may carry out biopsy- taking a small amount of tissues from the thyroid to see if it contains cancer.
Types of Thyroid Cancer
Based on how the cancer cells look when studied under a microscope, thyroid cancer can be classified into four main types: papillary, medullary, follicular and anaplastic. Prognosis (chance of recovery), depends entirely on the type of thyroid cancer, if it is found in the thyroid or has spread to other body parts (stage), and the age and overall health of the patient. The growth of these types of cancers is different- some grow faster than others.
Cancer arises from cells undergoing malignant transformation and begin to divide and multiply abnormally. Normally, tumor may grow slowly and progress rapidly and spread or invade other tissues. The four types of thyroid cancer are discussed below.
This is the common thyroid cancer type, accounting for about 70-80% of reported cases. It is a slow-growing and differentiated type that develops from follicular cells. It can develop in both or one lobe of the thyroid gland. Papillary carcinoma may spread to the lymph nodes around the neck, but with proper prognosis, it can easily be treated. It is usually diagnosed in younger people, between the age of 30 and 50 years. It affects females mostly, about three times often than men. The development of the tumor can be related to exposure to radiation from acne treatment for instance or adenoid problems during childhood.
The 2nd most common thyroid cancer type, accounting for approximately a tenth of reported cases. It is common in countries where there is insufficient intake of iodine. This cancer type of the thyroid glands is also differentiated form. It is in most cases, associated with good prognosis, though it is aggressive compared to papillary cancer. The Follicular carcinomas don’t spread to other areas of the neck or lymph nodes. They however, spread to nearby organs such as the lungs or bones.
Medullary Thyroid Carcinoma
This type develops from C-cells found in the thyroid gland. Medullary thyroid cancer is aggressive but less differentiated than the other two types of cancers already discussed above. Approximately 4% thyroid cancer cases are likely to be of this sub-type. These cancers spread more to nearby organs, and more so to the lymph nodes as compared with the other more differentiated cancers of the thyroid. In most cases, they release high levels of calcitonin as well as carcino-embryonic antigen (CEA), which is easily detectable by blood tests. It can be easier to control medullary thyroid cancer if it is found before and treated before it can spread to other body parts.
Anaplastic Thyroid Cancer
Not more than 1 person out of 20 thyroid cancer diagnosed people have this cancer type, accounting about 5%. It is usually diagnosed in older people, patients older than 65 years. Most reported cases are female related than men. Anaplastic thyroid cancer is aggressive and invasive and has the least responsive to treatment. Since it is very aggressive, it spreads quickly to other body parts- the neck and the body.