The treatment and course of the disease depend on the type of thyroid cell the cancer originates from. Thyroid cancer affects more women than men and the average age at diagnosis is 45-50 years.
Differentiated carcinomas are the most common type of thyroid cancer (>90% of cases) and include papillary and follicular types. Their cell structures most closely resemble that of normal thyroid tissue, so they are usually less aggressive. Like normal thyroid tissue, differentiated thyroid carcinoma cells have the ability to take up iodine and can be selectively treated with surgery followed by therapy with radioactive iodine.
Medullary carcinomas account for <5% of all thyroid carcinomas. This type of thyroid cancer is often genetic and originates from the so-called parafollicular cells (C cells). Found in small clusters in the thyroid, these are cells that produce the hormone calcitonin which is especially important for bone health.
Undifferentiated or anaplastic carcinomas
Undifferentiated or anaplastic carcinomas are one of the rarer forms of thyroid cancer, accounting for around 1% of cases. This is the most aggressive form of thyroid cancer and neighbouring organs are often already affected by the time it is diagnosed.