Thyroid cancer: What is it? What are the signs and symptoms of thyroid cancer ? How to prevent thyroid cancer?

Thyroid cancer: What is it?

Thyroid cancer is a rather rare cancer. It is recorded in France 4000 new cases per year (for 40 000 breast cancers). It concerns women at 75%. Its incidence is increasing in all countries.

In Canada, in 2010, thyroid cancer was diagnosed in approximately 1 000 males and 4 100 females. This cancer is ranked 5th in female cancers (4.9% of cases), but represents only 0.3% of female cancer mortality. The diagnosis usually occurs in people aged 25 years to 65 years.

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 that diagnosis is more common. In fact, we can now detect small, previously invisible tumors.

Risk factors.

Thyroid cancer is favored by exposure of the thyroid to radiation, either due to radiotherapy treatments at the head, neck or upper thorax, especially during childhood, or due to fallout Radioactive in areas where nuclear tests were carried out or after a nuclear accident such as that of Chernobyl. Cancer can occur several years after exposure.

The increase in thyroid cancer.

A family history of thyroid cancer or genetic syndrome (such as the Adenomatous family Polypose) is sometimes found. We’ve identified a gene mutation that promotes medullary thyroid cancer.
Thyroid cancer may develop on a goiter or a thyroid nodule (about 5% of the nodules are cancerous).

Several types of cancer.

The thyroid comprises three types of cells: follicular (which secretes thyroid hormones), parafolliculars located around them and secreting calcitonin (involved in calcium metabolism), as well as non- Specialized (supporting tissues or blood vessels).

Cancers develop from follicular cells in more than 90% of cases; Depending on the appearance of cancer cells, one speaks of either papillary (in 8 of 10 cases) or vesicular cancers. These cancers evolve slowly and are susceptible to treatment with radioactive iodine.

More rarely (10% of cases), medullary cancer-develops from parafollicular cells or from non-mature cells, these tumors being said to be undifferentiated or anaplastic. Medullary and anaplastic cancers evolve faster and are more difficult to treat.

What are the signs and  symptoms of thyroid cancer ?

At the onset of the disease, thyroid cancer usually does not cause any signs or symptoms. It can be discovered then “by chance ” During palpation of the neck or a cervical ultrasound performed for another cause.

It can also be discovered when monitoring a goiter or a benign nodule.

With its evolution, one or the other of the following symptoms may appear, but they are in the vast majority of cases related to benign thyroid abnormalities (95% of the thyroid masses are benign nodules) or to other more banal pathologies:

• More or less painful discomfort at the neck or throat level
• palpable or visible mass at the front of the neck or on the sides and corresponding to adenopathies (enlarged lymph nodes;
• Change of voice, which becomes hoarser;
• Difficulty swallowing or breathing
• More or less painful discomfort at the neck or throat level
• Modification of a known nodule or goiter.

Can we prevent thyroid cancer?

There is no real prevention in itself, but people who have been treated by irradiation at the head and neck level or those living in areas where nuclear tests have been carried out should be given regular, simple monitoring (palpation of the thyroid region).

The few people who are at very high risk of thyroid cancer due to a genetic mutation can discuss with their doctor the interest of a possible preventive thyroidectomie, in order to remove the thyroid gland. The pros and cons of this option must be weighed well.

For people living in the vicinity of a nuclear power plant, emergency measures to protect the thyroid gland are foreseen in the event of an accident that would be accompanied by discharges of nuclear waste. Potassium iodide, also known as “stable iodine”, is a drug that blocks the effects of radioactive iodine on the thyroid. The thyroid gland sets the iodine, whether radioactive or not. By saturating the gland with a non-radioactive iodine, the risk of damage can be reduced.

The methods of distribution of this medicine vary from one municipality to another and from one country to another. People who live in the vicinity of a power plant can get information from their municipality.