Thyroid Cancer – An Overview

Thyroid is a butterfly shaped gland at the base of neck. It secrets thyroxine hormone which is essential for body functions. Thyroid cancers are relatively low incidence cancers with relative frequency of 0.1 to 0.2 % amongst all cancers. Risk factors for cancer of thyroid are female sex, exposure to high dose of radiation in neck area and certain genetic syndromes.

Thyroid cancer is most common after age of 30 and aggressiveness increases with increasing age. Approximately 1.2 % of all women and men will be diagnosed with thyroid cancer in their whole life. Thyroid cancers can be differentiated into well differentiated cancers which include papillary variant, follicular variant and hurthle cell variant , medullary thyroid cancer and anaplastic cancer.

Most common group are well differentiated cancers out of which papillary cancer is the most common which constitutes about 77% of all thyroid cancers. Most common presentation is with swelling in lower neck. Sometimes findings is a nodule detected incidentally on neck ultrasound. Only 1% of thyroid nodules are cancerous.

Patient is investigated with ultrasound of neck and ultrasound guided FNAC. Hurthle cell variant and follicular variant cannot be diagnosed with FNAC . CECT scan and MRI neck are used for evaluation and staging of locally advanced disease.

Treatment of all kinds of thyroid cancers is removal of thyroid gland with dissection of lymph nodes if involved. Medullary cancer requires complete bilateral neck nodal dissection.. the surgical removal should only be done by a surgeon well versed in the art of head and neck cancer surgery for achieving optimum cure.

Most common complication of surgery is injury to parathyroid glands which lead to hypocalcemia needing life long calcium therapy. Patients may need postoperative radioiodine therapy depending on the final pathological staging of the disease..

Anaplastic type has the worst prognosis. In fact it is one of the most incurable cancers found in human body. It usually presents in a very advanced stage and leads to rapid progression and rapid and untimely death . Only this type of thyroid cancer requires chemotherapy and radiation.

The survival rates of well differentiated thyroid cancers is around 80% over a period of 20 yrs with survival of 98% of patients who present with early disease in patients aged less than 45 years.