Thyroid cancer: what is it?
Thyroid cancer is a rather rare cancer. There are 4000 new cases in France per year (for 40 breast cancers). It concerns women at 000%. Its incidence is increasing in all countries.
In Canada in 2010, thyroid cancer was diagnosed in approximately 1 men and 000 women. This cancer comes at 4e rank of female cancers (4,9% of cases), but accounts for only 0,3% of cancer mortality in women. the diagnostic Usually occurs in people between the ages of 25 and 65.
This cancer is often detected at an early stage. The treatment is then very effective with a cure in 90% of cases. Improved screening techniques could also explain why the diagnosis is more frequent. Indeed, we can now detect small tumors that were once invisible.
Risk factors
Thyroid cancer is promoted by exposure of the thyroid to radiation, either from radiation therapy to the head, neck or upper chest, especially in childhood, or by due to radioactive fallout in areas where nuclear tests have been carried out, either after a nuclear accident such as the one at Chernobyl. Cancer can appear several years after exposure.
The increase in thyroid cancer.
There is sometimes a family history of thyroid cancer or a genetic syndrome (such as familial adenomatous polyposis). A gene mutation has been identified that promotes medullary thyroid cancer.
Thyroid cancer can develop on a goiter or thyroid nodule (about 5% of nodules are cancerous).
Several types of cancer
The thyroid is made up of three types of cells: follicular cells (which secrete thyroid hormones), parafollicular cells located around them and secreting calcitonin (involved in calcium metabolism), as well as unspecialized cells (supporting tissues or blood vessels) .
Cancers develop from follicular cells in more than 90% of cases; depending on the appearance of the cancer cells, we speak of either papillary cancers (in 8 out of 10 cases) or vesicular cancers. These cancers grow slowly and are sensitive to radioactive iodine treatments.
More rarely (10% of cases), medullary cancer develops from parafollicular cells or from immature cells, these tumors being said to be undifferentiated or anaplastic. Spinal cord and anaplastic cancers grow faster and are more difficult to treat.