Thyroid cancer: What you need to know

Associate Professor Luke Tan of the ENT-Head & Neck Cancer and Thyroid Surgery Centre talks about lumps in the neck and thyroid cancer.

Does having a lump in the neck mean you have cancer?

No. Neck lumps usually arise because of one of two reasons, an enlargement of the lymph node or a lump in the thyroid. In both cases, it could be a sign of cancer but this is not always the case.

Lymph node enlargement is usually caused by infection, whether viral or bacterial. For example, it could be caused by a chronic infection like tuberculosis. If the cause is not infection, then cancer could be a possible cause. The cancer could be a primary cancer like lymphoma, or the result of a metastatic cancer of the lymph nodes that affect the nose, the throat, tongue, tonsils or voice box.

Thyroid lumps are caused by a thyroid cyst or a solid thyroid lump. Thyroid cysts are usually benign. The risk of cancer from a thyroid cyst is less than one per cent and usually, it is only removed when it causes problems.

Solid thyroid lumps have a higher risk of being cancerous, and are thus of greater concern. A solid mass of the thyroid can be a single mass, or it can be made up of multiple smaller masses, known as a multi-nodular goiter. A single mass has a higher risk of cancer whereas a multi-nodule mass has a low risk of cancer.

How do doctors determine what kind of lump it is?

To see if a thyroid lump is caused by a cyst or nodule, doctors use ultrasound. Ultrasound is also used to determine if a solid thyroid lump is a single mass or a multi-nodule one.

If it is a cyst, the doctor will use a fine needle to remove the fluid and examine it for cancer cells. Sometimes, this procedure decompresses the cyst completely, and if there is no cancer then nothing else needs to be done. Decompressing the cyst is an outpatient procedure.

If it is a multi-nodular lump, the likelihood that it is cancerous is low but the doctor will still look for signs of cancer such as the lump drawing blood, or if there is micro calcification (little white dots within the lump), or if the edges of the lumps are irregular which shows that it is invading nearby tissue rather than expanding. If there is a dominant nodule within the multi-nodule, then a fine needle biopsy will be done to extract cells to confirm if it is cancerous or not.

If the biopsy confirms that it is not cancerous, then it safe to leave the lump alone unless it is causing problems like interfering with breathing or speech.

If it is a single solid nodule, the likelihood of cancer is one in 10. The doctor will do a fine needle biopsy to determine if it is cancerous or not.

What are the causes of thyroid cancer?

No one knows for sure what the causes are. However, there are certain well-known risk factors. One of them is radiation exposure, specifically to ionising radiation. Thyroid cancer among children is one of the major results of exposure to radiation following the disaster at Cherynobyl in 1986.

Some people have a family history of thyroid cancer, but this is a minority.

No one is sure why but thyroid cancer affects women more than men. About 60 percent of people with thyroid cancer are women, two-thirds of whom are between 20 and 40 years old.

Many times, there are no symptoms beyond the lump – so it is safer to have a lump checked even if there are no other symptoms. This is so that you can catch it when it is small.

What is the treatment for thyroid cancer?

If the biopsy indicates that the lump or cyst is cancerous, the predominant treatment is surgery. The good news is that the majority of thyroid cancers are well differentiated cancers, which means that they grow slowly, over one to two years.

The surgery is a relatively straightforward procedure that usually takes one to two hours and patients will be able to leave the hospital in three days. There is a risk of injury to the nerve to the vocal cords, which would cause hoarseness. However, an experienced surgeon will be able to lower this risk considerably.

Open surgery is usually recommended, but robotic surgery is available if cosmetic considerations are important. The scar is usually hidden in the armpit or the hairline. During the surgery, the surgeon also removes lymph nodes that are enlarged.

After surgery to remove a cancerous tumour, radioiodine will be given, in liquid or capsule form, to see if the cancer has spread, and to wipe out all remnant thyroid cancer cells. Patients will also need to go on thyroid hormone therapy to replace their missing thyroid. It is an inexpensive tablet that is taken daily.

Because it is a relatively slow growing cancer, about 95 per cent of patients who seek treatment are in Stage 1. The 25-year survival rate is over 90 per cent.

By Jimmy Yap

POSTED IN Cancer Treatments
TAGS cancer diagnosis, cancer lump, cancer ultrasound, cancerous cyst, dr luke tan, head & neck (ENT) cancer, robotic surgery, swollen lymph node, thyroid cancer
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