The thyroid is a gland located at the bottom of the neck. Its function is to manufacture hormones responsible for controlling many aspects of a person's metabolism. Thyroid cancer occurs when abnormal cells begin to grow. There are four kinds of thyroid cancer and different stages to describe how advanced a particular type of cancer has become. Staging for thyroid cancer is important because treatment for the disease varies.
Papillary and follicular thyroid cancer
Seven out of 10 thyroid cancer cases involve papillary cancer, in which tumors form in the thyroid tissue--usually after exposure to a radiation source. This form of thyroid cancer does not normally spread far from the thyroid region and is very treatable. Fifteen percent of thyroid cancers are follicular cancers. This kind of cancer can spread to distant places in the patient, such as the lungs and liver, but is still curable. Follicular cancer will spread through the blood vessels rather than the lymph nodes, which is how papillary cancer spreads. Both of these types of thyroid cancers have similar stages.
Medullary and anaplastic thyroid cancer
Medullary thyroid cancer comes in two forms. One causes cancer on both sides of the gland and is called sporadic, while the other, known as familial, results in tumors that can bring any number of symptoms. Meduallary thyroid cancer is staged initially by the size of the cancer. When it is less than half an inch in size, it is at stage I--when it grows to between half an inch and an inch and a half, it is considered to be at stage II. Stage III medullary thyroid cancer has made its way into the lymph nodes, and stage IV sees the disease spread to other regions. A rare form of thyroid cancer, anaplastic cancer, spreads quickly.
Stages I and II
For papillary and follicular thyroid cancer, stages I and II are when the disease is limited to the thyroid. At this stage it is treatable with surgery. Even when the cancer has spread to the lymph nodes in the vicinity of the thyroid, the cancer is still at stage I or II in patients 45 or younger.
Stage III
In Stage III papillary and follicular thyroid cancer, the cancer has grown to be greater than 4 centimeters across. It is still confined to the thyroid or has spread a bit outside, with perhaps the lymph nodes near the trachea being affected. Again, the chances for recovery in patients under 45 in stage III are not lessened by this spread of the disease, unless it has made its way into the surrounding blood vessels or tissues in the neck.
Stage IV
At stage IV, in most cases the bones and the lungs are the targets for the spread of cancer, which is called metastasizing. Papillary cancer of the thyroid will usually travel to the lymph nodes and doesn't move too far from the thyroid. Follicular cancer can wind up anywhere in the body.
Tags: thyroid cancer, thyroid cancer, lymph nodes, follicular thyroid, follicular thyroid cancer, form thyroid, blood vessels