May 25 is World Thyroid Day.
Excerpt from Dr Umanath Nayak’s book “Enduring Cancer – Stories of Hope”. Dr Nayak is a Head and Neck Cancer surgeon, Apollo Cancer Hospitals, Hyderabad
‘Doctor, what do you think is the problem?’
The creases of worry on Deepa’s forehead made me hesitate. I told her about a couple of benign conditions to explain the swelling that had suddenly developed on her throat over the past few weeks. Though the thought of cancer did cross my mind, at that point of time I was not willing to consider cancerous lymph nodes as my first diagnosis. The swelling was diffuse and not well defined. My answer, however, did not seem to reassure Deepa. Especially since her brother, an orthopaedician known to me, had been quite insistent that she see me and the implications of that were not lost on her. As an oncologist, this is a problem I often face in my practice. Though I also see and operate on a good number of patients who do not have cancer—mostly those with benign thyroid nodules and tuberculous lymph glands—patients not already diagnosed with cancer are initially wary when they are referred to me. So in a way, my reputation precedes me!
In Deepa’s case, I was wrong and she did turn out to have cancer—cancer of the thyroid gland. The swelling in her neck was due to secondaries (metastasis) in the lymph nodes. She took the diagnosis quite well and listened calmly to the details of the treatment and the prognosis.
Cancer of the thyroid gland is an uncommon cancer and accounts for just about 1%–1.5% of all cancers. In the USA, the incidence of this cancer has shown a 2.4-fold increase in the last three decades (from 3.6 per 100,000 of the population in 1973 to 8.7 per 100,000 in 2004). This is believed to be due more to better diagnostic facilities such as ultrasound, which can pick up thyroid nodules much earlier, rather than any true increase in the incidence of the cancer. Exposure to ionizing radiation is one of the known risk factors for the development of thyroid cancer and the cancer often develops decades after the exposure has occurred. It is interesting to note that after the atomic bomb explosion in Hiroshima and Nagasaki, the incidence of thyroid cancer among the survivors increased by 200 times compared to the population which was not exposed to the effects of the bombing. Even today, after over six decades, the survivors of the bomb, known in Japan as ‘hibakusha’, continue to be regularly diagnosed with not only cancer of the thyroid, but also with leukaemias, lymphomas and other cancers. Following the Chernobyl nuclear disaster, too, a study of 1000 inhabitants exposed to the radiation found that 62 developed thyroid cancer in the first 10 years after the exposure.
Fortunately, the regular type of thyroid cancer (commonly referred to as well-differentiated thyroid cancer) is one of the most curable cancers known and provided that adequate surgery is performed, most young patients with this cancer live their normal lifespan. Surprisingly, older patients with this cancer do not do so well. This is the only cancer in which the age of the patient is a very important factor determining the aggressiveness of the cancer and survival. One variant of thyroid cancer, the medullary carcinoma of thyroid or MCT, has a genetic basis and a sub-group of patients with this condition have been found to carry an abnormal gene, the RET proto-oncogene. The identification of this gene in subjects at risk (first-degree relatives of those with familial MCT) can predict with 100% accuracy the future development of thyroid cancer. Those who express this gene are advised a preventive thyroidectomy, sometimes even in childhood, before the clinical development of cancer. In certain cases in which the mutation indicates a very high risk, it is even recommended that the person undergo thyroidectomy as early as six months of age, though in practice, the majority of those identified with this gene undergo thyroidectomy at the age of around five years.
Deepa Tiwari is an example of the many young patients that I see with cancer of the thyroid. Young, smart, recently married to her steady boyfriend, Deepa works as a HR coordinator in Microsoft and loves to party. Not surprisingly, as her husband happens to be a DJ and likes to take her along for his professional engagements. In fact, the night before she was admitted to the hospital for her surgery, Deepa was seen at her favorite pub, dancing away her fears and apprehensions.
Deepa underwent a marathon five-hour operation to remove her thyroid gland and all the affected lymph nodes in her neck. During surgery, I was amazed to see that almost every possible site in her neck had enlarged nodes, and it was quite a challenge to remove all malignant disease and preserve the important nerves and other structures at the same time. Cancerous nodes had to be meticulously dissected from the large vein in the neck—the internal jugular vein, which drains blood from the head and neck region—at the same time taking care not to injure it. Damage to this vein could result in major haemorrhage. Any injury to the delicate nerves running along the sides of her thyroid gland could result in permanent hoarseness. These nerves were intimately surrounded by enlarged nodes and removing them while still leaving the nerves intact required all my skill and experience. She withstood this assault on her boldly and recovered well. The long scar running across the length of her neck was the only stigma of the extensive surgery she had undergone. High-dose radioactive iodine treatment was administered to her a month later. This treatment is routinely given post-operatively to all high-risk thyroid cancer patients to destroy any microscopic cancer that may be lurking unseen in any part of the body. Thyroid tissue (cancerous or otherwise) concentrates iodine and the radioactivity in the administered iodine destroys it. Following this treatment, Deepa was kept isolated for 72 hours, since the radioactivity she was emitting could be harmful to others around her. According to her, this was the most difficult part of her entire treatment—being in isolation and unable to see and talk to anyone for three entire days.
When I saw Deepa again three months after her surgery, she appeared quite cheerful, though philosophical. She continued with her parties and had her fun, but now took life somewhat more seriously. She valued certain things she had earlier taken for granted, such as spending time with her aged parents. She and her husband also took time out to be with each other more often. Thanks to supportive colleagues at work, she was able to cope with work pressures quite well. When asked if the scars on her neck bothered or embarrassed her, she dryly replied that there were far more important issues than that in life. She preferred not to dwell much on the uncertainties of the future and apprehensions about recurrence of the disease and survival.