Thyroid cancer occurs in the cells of the thyroid, which is a butterfly-shaped gland located at the base on the neck. The thyroid produces hormones that regulate the heart rate, body temperature and weight.
There are many types of thyroid cancer. Some grow very slowly and others can be very aggressive. Most thyroid cancer cases can be cured with treatment.
This is the most common kind of thyroid cancer, accounting for about 75% of cases. Papillary thyroid cancers are usually slow growing, but they tend to spread to the lymph nodes in the neck. Most of these cancers can be treated successfully.
There are many subtypes of papillary thyroid cancer. Some less common subtypes of this cancer (follicular variant, tall cell, insular, diffuse sclerosing) tend to be more aggressive and may grow and spread more quickly.
Follicular thyroid cancer is the second most common type of thyroid cancer which accounts for about 15% of cases. This cancer type tends to spread via the bloodstream to other parts of the body such as the lungs and bones.
Medullary thyroid cancer is much less common, accounting for about 5% of thyroid cancers. These cancers arise from the parafollicular C cells in the thyroid. These cells are usually responsible for producing a hormone called calcitonin, which helps to control the level of calcium in the body. Although the outcome of treatment for medullary thyroid cancer is not as good as for papillary and follicular thyroid cancers, many patients can still be treated successfully.
Anaplastic thyroid cancer is the most rare and accounts for about 2% of thyroid cancers. These cancers tend to be very aggressive and grow very quickly and spread rapidly to other parts of the body.
Thyroid cancer is more common in women than men. In Singapore, it is the 8th most common cancer diagnosed in women. Thyroid cancer is commonly diagnosed at a younger age than most other cancers, with most cases occurring in patients below the age of 60 years.