It is not just curable with this surgery, but even your quality of life will be unhampered and you will live as long as you would have, if you had not developed this disease." As I concluded my counselling to Eliz, a 25-year-old emerging architect who had come to me with a recent diagnosis of thyroid cancer, I saw rays of hope in her wet eyes. She thanked me and agreed for the surgery. Now, two years later, she is disease-free, has progressed in her career and life, with a will much stronger than before. As I reminisce her case and of others treated for thyroid cancer with similar outcomes, I can only thank the consistent effort of generations of medical scientists who have worked to bring about excellent outcomes in thyroid cancer treatment, for any disease of thyroid requiring surgery was considered doomed not long before.
Thyroid gland removal or thyroidectomy is one of the safest and most effective surgeries at present. Cancers of thyroid can be cured in about 90 per cent of patients by way of surgery and adjuvant therapy. It would be hard to believe that thyroidectomy was one of the most condemned surgeries till the latter part of 19th century, due to extremely high procedure-related mortality and morbidity rates. Cancers which have spread to distant parts of the body are usually treated with a palliative intent, as most of these are considered incurable. But in case of thyroid cancer, it is possible to treat and control disease which has spread to distant parts of the body with radio iodine therapy, which is a major leap and milestone in the treatment of any cancer. This change, from 75 per cent of patients dying from any form of thyroid surgery even for a non-cancer disease, to reaching the present cure rate with zero procedure-related death and extremely low morbidity, represents the battle waged by generations of medical scientists against this problem.
What is thyroid gland
Thyroid, the small butterfly-shaped gland situated in front of our neck, is essential for most of our bodily functions.
It may be hard to imagine that this small gland which weighs just about 25gm has control over almost all major functions of the body by way of its control over metabolism and protein synthesis. This starts right when you are in your mother's womb, for a deficiency of thyroxin, the hormone it produces, can severely hamper intellectual development.
It derives its name from the Greek 'Thyroideus', which means 'shield like', probably due to its shape. But by way of its function in shielding the body against numerous problems, thyroid gland justifies the meaning of that name. It plays an important role in controlling the basal metabolic rate of the body, cardiac rhythm, ensuring normal development, maintaining normal sexual function, sleep, thought patterns.
There has been an appreciable increase in the incidence of thyroid cancer in most parts of the world, including India, in the past few decades. There is an ongoing debate among physicians whether this is a real increase or an apparent increase in detection due to increasing imaging investigations. Though this is not clear, it is generally considered to be an increase in detection. However, mortality from thyroid cancer has seen a steady decline over the years. It is at present one of those cancers with the highest cure rates.
Treatment of thyroid cancer requires a multi modality approach, with surgery being the mainstay. Other treatment modalities like radioactive iodine, hormonal suppression and rarely external beam radiotherapy or chemotherapy may also be required as adjuvant.
At present, the five-year survival of differentiated thyroid cancer, which forms 90 per cent of all thyroid cancers, is close to 95 per cent. Complications of thyroid surgery are an injury to the recurrent laryngeal nerve, the voice nerve, which is very rare these days in expert hands, and mortality from surgery is almost unheard of. And today there are debates concerning ambulatory thyroid surgery and endoscopic thyroid surgery.
A major leap
Thyroid gland concentrates most of the iodine in the body, iodine being the essential ingredient for thyroid hormone production. The discovery of radioactive iodine made it possible to target even microscopic remnants of thyroid tissue, left after surgery, without significantly affecting any other organ in the body, as almost 80 per cent of the iodine is absorbed by thyroid tissue alone. Also, radio iodine made it possible to treat thyroid cancer which has spread to distant parts of the body. This was a paradigm shift in the treatment of cancer, as cancers which have spread to distant parts of the body are usually considered extremely difficult to treat. The role of external beam radiation in thyroid cancer has significantly come down after the emergence of radioactive iodine therapy.
Now we have emerging drugs which can act on molecular level targets involved in the causation of recurrent and advanced thyroid cancer. It may not be long before we can cure differentiated thyroid cancer of any stage with molecular targeted therapy.
Dr Shawn T. Joseph is head & neck surgical oncologist, VPS Lakeshore hospital, Kochi, Kerala.