An estimated 42 million people in India suffer thyroid diseases including goiter. Thyroid is a small gland in the neck that contains cells called Follicular Cells. These cells are responsible for making Thyroxine (T4) and Triiodothyronine (T3), which keeps the body functioning normally. C cells are also present in the Thyroid gland that makes a hormone which helps to control the level of calcium in the body.
However, unlike in the developing countries, Thyroid Cancer in India is rare. With the wider availability of scans and other diagnostic modalities, increasing number of patients are diagnosed with Thyroid nodule. Challenges in diagnosing Thyroid Cancer is equated to `detecting a needle in haystack’, that is, a large number of people have thyroid nodule, of which only a small proportion are cancerous.
Many people develop Thyroid Cancer for no particular reason. However, certain risk factors increase its chances. These include people who have pre-existing thyroid diseases such as Goiter or Inflammation. However, it is important to note that having Hypothyroidism and Hyperthyroidism does not increase the risk of Thyroid Cancer. Family history is another risk factor that cannot be ruled out.
Cancers of the Thyroid gland are divided into three main types, namely, Differentiated Thyroid Cancers, Anaplastic Thyroid Cancers, and Medullary Thyroid Cancers. Each one behaves differently from the other and foreshadow contrasting fates for the respective sufferers.
Differentiated Thyroid Cancer (or DTC) is, luckily, the most common Thyroid malignancy. Although there is no such thing as a good cancer, DTCs can be considered as a `good cancer’ as rarely patients die of this cancer; especially in those patients who are diagnosed at an early stage and are of a younger age group. By contrast, Anaplastic Thyroid Cancer (or ATC), are rare but one of the most aggressive human cancers. The disease progresses rapidly, and patients do poorly in spite of the best treatment available. The third type of thyroid malignancy, namely Medullary Thyroid Cancer (or MTC) is often familial.
The commonest and often the earliest symptom of Thyroid Cancer is a painless swelling in the neck. Rarely, patients can present with other symptoms such as change in voice, difficulty in eating. For the diagnosis of Thyroid Cancer the first test to perform is to estimate Thyroid hormone level, which is often normal in Thyroid Cancer. The next important test to be performed is an Ultrasound examination. This examination will allow the doctor to suspect the possible cancer.
Any suspected cancer nodule should undergo a needle biopsy examination, preferably under Ultrasound guidance so as not to miss suspicious areas of the nodule. If Thyroid Cancer is detected, few other tests may be recommended to assess the spread from Thyroid region. The final decision for treatment is taken putting the results of all the three test together to reach a working diagnosis. Knowing the type of cancer from the biopsy examination helps the doctors to recommend the most suitable treatment option.
Surgery is the main stay of treatment for Thyroid Cancer but it may be supplemented by Radio-Iodine Therapy and Thyroid Hormone Therapy. Considering the indolent nature of this cancer, there is a recent trend towards its management by limited surgery (known as Lobectomy) and using Radio-Iodine Therapy sparingly. Several minimally-invasive approaches also are now in use to limit both the side effects of surgery and to avoid a visible surgery scar.
The two main side effects of surgery are change in voice and low blood calcium. It has been demonstrated that these side effects are 20-fold lower in specialized centers treating high-volume of Thyroid Cancers.
In cancer patients, follow-up is as important as the treatment itself. Periodic clinical and Ultrasound examination along with blood testing is important since it allows early detection of disease relapse. Overall, if the cancers are diagnosed early and treated appropriately one can expect excellent chances of getting cured and a good quality of life.
The author, Dr. Vivek Shetty, is a Consultant Head and Neck Onco-Surgeon at Mazumdar Shaw Cancer Centre, Narayana Health City, Bangalore.
