Share on FacebookShare on Google+Tweet about this on TwitterShare on LinkedInPin on PinterestShare on RedditShare on TumblrShare on StumbleUponDigg thisEmail this to someoneBuffer this page

Thyroid cancer is a disease that you get when abnormal cells begin to grow in your thyroid gland . The thyroid gland is shaped like a butterfly and is located in the front of your neck. It makes hormones that regulate the way your body uses energy and that help your body work normally. The most common symptom of cancer of the thyroid is a painless lump or swelling that develops in the neck

Types of Thyroid Cancer

here are several different types of thyroid cancer, which are classified based on how similar they look to normal thyroid cells under a microscope and by the type of cell from which they develop.

  • Papillary carcinoma is the most common type of thyroid cancer, accounting for approximately 80 percent of cases. Papillary carcinomas are slow growing, differentiated cancers that develop from follicular cells and can develop in one or both lobes of the thyroid gland. This type of cancer may spread to nearby lymph nodes in the neck, but it is generally treatable with a good prognosis (outlook for survival).
  • Follicular carcinoma is the second most common type of thyroid cancer, and accounts for approximately one out of 10 cases. It is found more frequently in countries with an inadequate dietary intake of iodine. Follicular carcinoma is also a differentiated form of thyroid cancer. In most cases, it is associated with a good prognosis, although it is somewhat more aggressive than papillary cancer. Follicular carcinomas do not usually spread to nearby lymph nodes, but they are more likely than papillary cancers to spread to other organs, like the lungs or the bones.
  • Hürthle cell carcinoma, also known as oxyphil cell carcinoma, is a subtype of follicular carcinoma, and accounts for approximately 3 percent of all thyroid cancers.
  • Medullary thyroid carcinoma develops from C cells in the thyroid gland, and is more aggressive and less differentiated than papillary or follicular cancers. Approximately 4 percent of all thyroid cancers will be of the medullary subtype. These cancers are more likely to spread to lymph nodes and other organs, compared with the more differentiated thyroid cancers. They also frequently release high levels calcitonin and carcinoembryonic antigen (CEA), which can be detected by blood tests.
  • Anaplastic carcinoma is the most undifferentiated type of thyroid cancer, meaning that it looks the least like normal cells of the thyroid gland. As a result, it is a very aggressive form of cancer that quickly spreads to other parts of the neck and body. It occurs in approximately 2 percent of thyroid cancer cases.

Causes of Thyroid cancer

The main risk factors for developing thyroid cancer are:

  • having a thyroid condition
  • having a family history of thyroid cancer (in the case of medullary thyroid cancer)
  • having a bowel condition known as familial adenomatous polyposis (FAP)
  • acromegaly (a rare condition where the body produces too much growth hormone)
  • having previous benign (non-cancerous) breast conditions
  • weight and height
  • radiation exposure

Symptoms of Thyroid Cancer

The most common early sign of thyroid cancer is an unusual lump, nodule or swelling in the neck.

Other possible symptoms of thyroid cancer include:

  • Neck pain: In many cases, neck pain starts in the front. In some cases the neck pain may extend all the way to the ears.
  • Voice changes: Experiencing hoarseness or other voice changes that do not go away could be a sign of thyroid cancer.
  • Breathing problems: Sometimes thyroid cancer patients say it feels like they are breathing through a straw. This breathing difficulty is often a symptom of the disease.
  • Coughing: A cough that continues and is not related to a cold.
  • Trouble swallowing: A growth or nodule on the thyroid gland may interfere with swallowing

Stages of Thyroid cancer

The number staging depends on the type of thyroid cancer you have. There are different systems for:

Papillary and follicular thyroid cancer

The number stages for papillary and follicular thyroid cancer are the same. These types are classed as differentiated thyroid cancers. There are 4 number stages. These cancers are staged differently depending on your age. These types of thyroid cancer tend to respond well to treatment, particularly if you are younger.

If you are under 45

Stage 1 means you have thyroid cancer which may or may not have spread to nearby lymph nodes. The tumour can be any size but has not spread to distant areas of the body. In TNM staging, this is the same as Any T, Any N, M0.

Stage 2 means your cancer has spread to other parts of the body (Any T, Any N, M1).

If you are over 45

Stage 1 means your cancer is only inside the thyroid and is less than 2cm across (T1, N0, M0).

Stage 2 means your cancer is between 2cm and 4cm across, and is only inside the thyroid (T2, N0, M0).

Stage 3 means the tumour is

  • larger than 4 cm or has grown slightly outside the thyroid, but it has not spread to nearby lymph nodes or other parts of the body (T3, N0, M0)
  • any size within the thyroid gland or has started to grow slightly outside the thyroid. It has spread to lymph nodes close to the thyroid in the neck but not to other parts of the body (T1-T3, N1a, M0)

Stage 4 is divided into 3 groups from A to C

Stage 4A means the tumour

  • has grown beyond the thyroid gland and into nearby tissues in the neck. It may or may not have spread to nearby lymph nodes but has not spread to other parts of the body (T4a, N0 or N1a, M0) OR
  • is any size and may have grown into nearby tissues in the neck. It has spread to certain lymph nodes in the neck (cervical nodes) or to lymph nodes in the upper chest (the superior mediastinal nodes) or behind the throat (retropharyngeal nodes) but not to other parts of the body (T1-T4a, N1b, M0)

Stage 4B means the tumour has grown into the area surrounding the bones of the spine or into nearby large blood vessels. It may or may not have spread to nearby lymph nodes, but it has not spread to other parts of the body (T4b, Any N, M0).

Stage 4C means the cancer has spread to other parts of the body (Any T, Any N, M1).

Medullary thyroid cancer

There are 4 number stages for people of any age with medullary thyroid cancer.

Stage 1 means that the tumour is 2 cm or less across and has not grown outside the thyroid. It has not spread to nearby lymph nodes or other parts of the body. In TNM staging, this is the same as T1, N0, M0.

Stage 2 means the tumour is

  • between 2 cm and 4cm across and has not grown outside the thyroid at all (T2, N0, M0) OR
  • larger than 4 cm or has grown slightly outside the thyroid, but has not spread to nearby lymph nodes or other parts of the body (T3, N0, M0)

Stage 3 means that the tumour is any size within the thyroid gland or has started to grow slightly outside the thyroid. It has spread to lymph nodes close to the thyroid in the neck but not to other parts of the body (T1-T3, N1a, M0).

Stage 4 is divided into 3 groups from A to C

Stage 4A means the tumour

  • has grown beyond the thyroid gland and into nearby tissues of the neck. It may or may not have spread to nearby lymph nodes but has not spread to other parts of the body (T4a, N0 or N1a, M0) OR
  • is any size and may have grown into nearby tissues in the neck. It has spread to the cervical lymph nodes in the neck or to nodes in the upper chest (the superior mediastinal nodes) or behind the throat (retropharyngeal nodes), but not to other parts of the body (T1 to T4a, N1b, M0)

Stage 4B means the tumour has grown into the area surrounding the bones of the spine or into nearby large blood vessels. It may or may not have spread to nearby lymph nodes, but it has not spread to other parts of the body (T4b, Any N, M0).

Stage 4C means the cancer has spread to other parts of the body.

Anaplastic (undifferentiated) thyroid cancer

All anaplastic thyroid cancers are considered to be stage 4 when they are diagnosed. This stage is divided into 3 groups from A to C.

Stage 4A means the tumour is still within the thyroid gland. It may or may not have spread to nearby lymph nodes, but has not spread to other parts of the body (T4a, Any N, M0).

Stage 4B means the tumour has grown outside the thyroid gland. It may or may not have spread to nearby lymph nodes, but has not spread to other parts of the body (T4b, Any N, M0).

Stage 4C means the cancer has spread to other parts of the body (Any T, Any N, M1).

Diagnosis of Thyroid Cancer

Apart from Physical and Medical examination , following test are also conducted

Biopsy

The actual diagnosis of thyroid cancer is made with a biopsy, in which cells from the suspicious area are removed and looked at under a microscope

Imaging tests

Imaging tests may be done for a number of reasons, including to help find suspicious areas that might be cancer, to learn how far cancer may have spread, and to help determine if treatment is working

Ultrasound

Ultrasound uses sound waves to create images of parts of your body. For this test, a small, wand-like instrument called atransducer is placed on the skin in front of your thyroid gland. It gives off sound waves and picks up the echoes as they bounce off the thyroid. The echoes are converted by a computer into a black and white image on a computer screen. You are not exposed to radiation during this test.

This test can help determine if a thyroid nodule is solid or filled with fluid. (Solid nodules are more likely to be cancerous.) It can also be used to check the number and size of thyroid nodules

Radioiodine scan

Radioiodine scans can be used to help determine if someone with a lump in the neck might have thyroid cancer. They are also often used in people who have already been diagnosed with differentiated (papillary, follicular, or Hürthle cell) thyroid cancer to help show if it has spread

Chest x-ray

If you have been diagnosed with thyroid cancer (especially follicular thyroid cancer), a plain x-ray of your chest may be done to see if cancer has spread to your lungs

Computed tomography (CT) scan

The CT scan is an x-ray test that produces detailed cross-sectional images of your body. It can help determine the location and size of thyroid cancers and whether they have spread to nearby areas, although ultrasound is usually the test of choice. A CT scan can also be used to look for spread into distant organs such as the lungs.

Magnetic resonance imaging (MRI) scan

Like CT scans, MRI scans can be used to look for cancer in the thyroid, or cancer that has spread to nearby or distant parts of the body

Positron emission tomography (PET) scan

For a PET scan, a radioactive substance (usually a type of sugar related to glucose, known as FDG) is injected into the blood. The amount of radioactivity used is very low. Because cancer cells in the body grow quickly, they absorb more of the sugar than normal cells. After waiting about an hour, you lie on a table in the PET scanner for about 30 minutes while a special camera creates a picture of areas of radioactivity in the body

Blood tests

Blood tests alone can’t tell if a thyroid nodule is cancerous. But they can help show if the thyroid is working normally, which may help the doctor decide what other tests may be needed.

Thyroid-stimulating hormone (TSH)

Tests of blood levels of thyroid-stimulating hormone (TSH or thyrotropin) may be used to check the overall activity of your thyroid gland. Levels of TSH, which is made by the pituitary gland, may be high if the thyroid is not making enough hormones

T3 and T4 (thyroid hormones)

These are the main hormones made by the thyroid gland. Levels of these hormones may also be measured to get a sense of thyroid gland function. The T3 and T4 levels are usually normal in thyroid cancer.

Thyroglobulin

Thyroglobulin is a protein made by the thyroid gland. Measuring the thyroglobulin level in the blood can’t be used to diagnose thyroid cancer, but it can be helpful after treatment

Calcitonin: For the body to use calcium efficiently, calcitonin hormone is released in the thyroid gland. On examining the levels of Calcitonin, possible detection of Medullary thyroid cancer can be done. Recurrence of the cancer after treatment can also be checked by testing the levels of Calcitonin.

Other tests

Vocal cord exam (laryngoscopy)

Thyroid tumors can sometimes affect the vocal cords. If you are going to have surgery to treat thyroid cancer, a procedure called a laryngoscopy will probably be done first to see if the vocal cords are moving normally. For this exam, the doctor looks down the throat at the larynx (voice box) with special mirrors or with a laryngoscope, a thin tube with a light and a lens on the end for viewing.

Treatment of Thyroid Cancer

After thyroid cancer is found and staged, your cancer care team will discuss your treatment options with you. It is important to take the time to consider each of your options. In choosing a treatment plan, factors to consider include the type and stage of the cancer and your general health. The treatment options for thyroid cancer might include.

Surgery

Surgery is the main treatment in nearly every case of thyroid cancer, except for some anaplastic thyroid cancers. If thyroid cancer is diagnosed by a fine needle aspiration (FNA) biopsy, surgery to remove the tumor and all or part of the remaining thyroid gland is usually recommended.

Lobectomy

This operation is sometimes used to treat differentiated (papillary or follicular) thyroid cancers that are small and show no signs of spread beyond the thyroid gland. First, the surgeon makes an incision (cut) a few inches long across the front of the neck and exposes the thyroid. The lobe containing the cancer is then removed, usually along with the isthmus (the small piece of the gland that acts as a bridge between the left and right lobes).

Thyroidectomy

Thyroidectomy is surgery to remove the thyroid gland. As with lobectomy, this is typically done through an incision a few inches long across the front of the neck

Lymph node removal

If cancer has spread to nearby lymph nodes in the neck, these will be removed at the same time surgery is done on the thyroid. This is especially important for treatment of medullary thyroid cancer and for anaplastic cancer (when surgery is an option).

Radioactive iodine (radioiodine) therapy

Thyroid gland absorbs nearly all of the iodine in your body. When radioactive iodine (RAI), also known as I-131, is taken into the body in liquid or capsule form, it concentrates in thyroid cells. The radiation can destroy the thyroid gland and any other thyroid cells (including cancer cells) that take up iodine, with little effect on the rest of your body.

Thyroid hormone therapy

Taking daily pills of thyroid hormone (thyroid hormone therapy) can serve 2 purposes:

  • It can help maintain the body’s normal metabolism (by replacing missing thyroid hormone after surgery).
  • It can help stop any remaining cancer cells from growing (by lowering TSH levels).

After a thyroidectomy, the body can no longer make the thyroid hormone it needs, so patients must take thyroid hormone (levothyroxine) pills to replace the loss of the natural hormone.

Taking thyroid hormone may also help prevent some thyroid cancers from returning.

External beam radiation therapy

External beam radiation therapy uses high-energy rays (or particles) to destroy cancer cells or slow their growth. A carefully focused beam of radiation is delivered from a machine outside the body. Generally, this type of radiation treatment is not used for cancers that take up iodine (that is, most differentiated thyroid cancers), which are better treated with radioiodine therapy. It is more often used as part of the treatment for medullary thyroid cancer and anaplastic thyroid cancer.

Chemotherapy

Chemotherapy (chemo) uses anti-cancer drugs that are injected into a vein or muscle, or are taken by mouth. Chemotherapy is systemic therapy, which means that the drug enters the bloodstream and travels throughout the body to reach and destroy cancer cells.

Targeted therapy

Targeted therapy is a type of treatment that uses dru Tyrosine kinase inhibitor therapy is a type of targeted therapy that blocks signals needed for tumors to grow gs or other substances to identify and attack specific cancer cells without harming normal cells.