Thyroid & Endocrine Cancers
Endocrine cancers are malignancies that affect the endocrine system, a network of glands responsible for producing and secreting hormones. The most common type is thyroid cancer, which originates in the thyroid gland, a butterfly-shaped gland at the base of the neck. Other endocrine cancers are much rarer and include those of the adrenal glands, pancreas (some types), and pituitary gland. While many endocrine cancers, especially thyroid cancer, are highly treatable, they can vary in their aggressiveness.
Key Risk Factors
Risk factors for thyroid and other endocrine cancers often involve a combination of genetic and environmental factors.
Radiation Exposure: This is the most established risk factor for thyroid cancer, particularly exposure during childhood or adolescence from medical treatments (like radiation for head and neck cancers) or environmental sources.
Genetics: A family history of thyroid cancer or certain inherited genetic syndromes significantly increases the risk. For example, the MEN2 (Multiple Endocrine Neoplasia type 2) syndrome is a key risk factor for medullary thyroid cancer.
Gender and Age: Thyroid cancer is about three times more common in women than in men. It can occur at any age but is most frequently diagnosed in women in their 40s and 50s and men in their 60s and 70s.
Iodine Intake: Inadequate iodine intake can increase the risk of follicular thyroid cancer, whereas excess iodine intake can also be a risk factor.
Epidemiology
In India, the epidemiology of thyroid cancer has some specific characteristics.
Rising Incidence: The incidence of thyroid cancer in India is rising, particularly in urban areas. This trend is believed to be due to improved diagnostic techniques, which can detect smaller tumours, as well as a greater awareness among the population.
Female Predominance: As in other parts of the world, thyroid cancer in India has a strong female predominance.
Geographic Variations: Studies in India have shown regional variations, with a higher incidence of thyroid cancer in coastal areas, which may be related to differences in iodine intake.
Histology: The most common type of thyroid cancer in India is papillary carcinoma, which generally has an excellent prognosis.
Typical Symptoms
Early-stage thyroid cancer often doesn't cause any symptoms. As the cancer grows, it can manifest with the following signs:
A Lump in the Neck: This is the most common symptom. The lump or nodule is typically painless and can be felt through the skin at the base of the neck.
Changes in Voice: Hoarseness or a change in voice that persists and is not due to a cold or infection.
Difficulty Swallowing or Breathing: As the tumour grows, it can press on the oesophagus or windpipe, making it difficult to swallow or causing a feeling of something being "stuck" in the throat.
Neck Pain: Pain in the front of the neck that may radiate up to the ears.
Swollen Lymph Nodes: Enlarged lymph nodes in the neck can be a sign that the cancer has spread.
Treatment Approaches
The treatment for thyroid cancer is highly effective, and the approach depends on the type and stage of the cancer.
Surgery: This is the primary treatment for most thyroid cancers. A thyroidectomy (removal of the entire thyroid gland) or a lobectomy (removal of one lobe of the thyroid) is performed to remove the tumour.
Radioactive Iodine (RAI) Therapy: Used after surgery for differentiated thyroid cancers (papillary and follicular) to destroy any remaining thyroid tissue or cancer cells.
External Beam Radiation Therapy: High-energy rays are used to kill cancer cells, often reserved for more aggressive or advanced cancers that do not respond to RAI therapy.
Thyroid Hormone Therapy: After a thyroidectomy, patients need to take thyroid hormone replacement pills for life to maintain normal metabolism and suppress the production of TSH, which can stimulate the growth of some thyroid cancers.
Targeted Therapy and Immunotherapy: For advanced or rare types of endocrine cancers, newer treatments that specifically target cancer cells or boost the body's immune system may be used.