Coming up next week is National Thyroid Cancer Awareness Week, mandated by Republic Act 10786 which sets the fourth week of September as the time dedicated to inform the public of this condition. Thyroid cancer is the most prevalent endocrine-related cancer in the Philippines.

The thyroid is a small butterfly-shaped gland just above your collarbone in the front of the neck. It makes thyroid hormone, a substance that controls your metabolism.

Any enlargement of the thyroid is called a goiter. The whole thyroid can be enlarged, or just a small part which can be a cyst that is filled with fluid, or a nodule if it is a solid mass. Thyroid nodules are common and can go undetected until they grow large enough to be visible or felt in the neck, or they may be found incidentally when another test is done like a CT scan or X-ray of the head and neck or the chest, done for other reasons.

Most thyroid cancers don't cause any signs or symptoms early in the disease. Concerning signs and symptoms include rapid growth of thyroid nodules; changes to your voice, including increasing hoarseness; difficulty swallowing; and swollen lymph nodes on the side of the neck.

Risk factors for thyroid cancer include:

•Exposure of the head and neck to radiation in childhood

•Genetic mutations, such as medullary thyroid carcinoma, which can run in families

•Iodine deficiency may make patients with goiter be more susceptible to some types of thyroid cancer

•Significantly more females than males are diagnosed with thyroid cancer

Most thyroid nodules are usually benign masses and not cancer. But once a thyroid nodule is discovered it should be evaluated to check that it is not cancer. A neck ultrasound is the best test to evaluate a thyroid nodule. The size and appearance of these nodules are described and a scoring system is used to assess the possibility of the presence of cancer.