KOCHI: It has become important to detect thyroid diseases earlier to avoid further complications including cancer. This is especially significant in India since there are about 5 crores of Indians with goitre.Thyroid disease can be due to congenital, infective, inflammatory or neoplastic causes. Thyroid cancer although common is diagnosed late because many patients are asymptomatic except for a thyroid swelling or lump in the thyroid.
Of all cancers, thyroid cancer constitutes only 3.5%, but it is the 2nd commonest cancer in women according to the Cancer Registry published by RCC, Trivandrum (1982-2011). Globally there are 32 L of thyroid cancer patients and the incidence of new cases per year is 3 lakh. 32,000 patients with thyroid cancer die annually.
In Kerala, the number of thyroid cancer patients seen in RCC over the last 30 years is about 12,000 ie. about 400/year. But there is a rising number of thyroid cancer patients in the period between 2007 – 2011 (950) as compared to 1982 – 1986 (123). The maximum number is seen in the age group 15.-34 (36%) and then in the age group 35-64 (22%), while the incidence is rare after the age of 65 years. Thyroid cancer is more common in women (3:1).
Since the survival rate is 98% after 5 years, thyroid cancer is considered as a benign disease. The cause of thyroid cancer is genetic in 10% of patients. Smoking, autoimmunity, previous external radiation (therapeutic or accidental) and pre-existing thyroid nodules constitute the rest. People who are exposed to external radiation of neck (as in older days for TB lymphadenitis) or after a nuclear reactor disaster (after Chernobyl accident in Ukraine, Fukushima in Japan) are susceptible for thyroid cancer. People residing in the adjoining areas of nuclear explosion sites had developed thyroid cancer, especially in children due to the radiation.
Treatment of the disease is always surgical – total removal of the thyroid gland and then supplemented with thyroxin for life. Survival depends on the type of thyroid cancer, the most fatal is ‘anaplastic thyroid carcinoma’. Another type of thyroid cancer is familial – Medullary Carcinoma thyroid, in which family members of the patient have to be investigated by testing blood for tumour markers. After surgery, these patients are subjected to ‘whole body scanning’ and then given oral radioactive iodine after admission in special isolation rooms to avoid radiation exposure to others. These inpatient facilities are available only in very few centres in Kerala, the first one was started in RCC in 1978 by the author.
Lumps or nodules in thyroid have to be subjected to further tests like ultrasound scan followed by fine needle aspiration cytology which is an OP procedure to exclude thyroid cancer. Recent research has proved that there is an increased prevalence of thyroid cancer in patients with ‘autoimmune thyroiditis’ in which thyroid antibodies are present in the patients’ blood. Nodules in the thyroid should not be left alone without further investigations especially in children.
These nodules may not have any tenderness or other signs or symptoms. Sometimes thyroid cancer can affect the vocal cord resulting in hoarseness of voice. Thyroid lumps or nodules are painless but dangerous. There is an adage among the public now -’ Given a chance to choose my cancer, I will pick only thyroid cancer’.
“Palpate the thyroid as you palpate the breast”
Dr K P PoulosePrincipal Consultant in Medicine
SUT Hospital, Pattom, Thiruvananthapuram
(The views expressed by the author are his own)