The Connecting Links Between Thyroid Nodules and Cancer

An estimated 42 million people in India suffer from thyroid problems, an autoimmune condition that has grown very common. The most frequent cause is thought to be iodine deficiency brought on by insufficient food consumption, which can result in diseases like goiter and hypothyroidism. Additionally, endocrine disorders are more common in women.

Thyroxine (T4) and triiodothyronine (T3) are produced by the thyroid, a butterfly-shaped gland situated in the neck beneath the Adam’s apple. These hormones are crucial for many biological processes, such as digestion, mood and excitability, body temperature, pulse and heart rate, and metabolism. However, terminology like thyroid cancer and thyroid nodules are becoming more popular these days, so it’s important to grasp how they relate to one another.

According to research, the prevalence of thyroid cancer is rising gradually globally, but the death rate has stayed the same. In India, there are 5.4 cases of thyroid cancer for every lakh people.

Understanding Thyroid Nodules

These are growths of small lumps on the thyroid glands. Thyroid nodules are classified as: Solitary (a single nodule), Multiple (more than one nodule), Cystic (fluid-filled), and Solid.

Causes of Thyroid Nodules

The following factors increase the risk of thyroid nodules: a history of head and neck radiation; a genetic predisposition to thyroid nodules or thyroid cancer; aging; iron-deficiency anemia; smoking; obesity; metabolic syndrome; alcohol use; elevated levels of the hormone insulin-like growth factor-1; and uterine fibroids. Thyroid nodules typically don’t warrant concern. Thyroid cancer can be found in some thyroid nodules, although the great majority of thyroid nodules are benign.

The majority of thyroid nodules arise for unknown reasons. Nodules can develop for many reasons, such as:

• One or more overgrowths of normal thyroid tissue are called colloid nodules. These growths are benign and not malignant. They don’t spread past your thyroid gland, even though they could get big. These thyroid nodule kinds are the most prevalent.
• Growths that are partially solid and partially filled with fluid are known as thyroid cysts. There is little chance of cancer (malignancy) from cystic nodules.
• Your thyroid gland’s continuous swelling (inflammation) leads to the development of inflammatory nodules. It’s possible that these growths won’t hurt.
• An enlarged thyroid, or multinodular goiter, is composed of several nodules, most of which are benign.
• The development of hyperthyroidism may result from the excess thyroid hormone produced by these nodules.
• Thyroid cancer occurs in less than 6.5 percent of thyroid nodules, making it extremely uncommon.

Symptoms of Thyroid Nodules

Thyroid nodules typically don’t show any symptoms. You might, however, be able to notice your nodules if you have a lot of them or if they are big. Rarely, nodules may expand to the point that they produce vocal abnormalities or hoarseness, difficulty swallowing or breathing, neck pain, and goiter, an enlargement of the thyroid gland.

Types of Thyroid Cancer

1. Papillary thyroid cancer is the most prevalent (80%), slow-growing, and frequently curable. Variants that grow more quickly, such as tall cells and columnar, may require more intensive treatment.
2. Follicular thyroid cancer spreads to the lungs or bones but has a fair prognosis and is associated with iodine deficit.
3. Oncocytic Carcinoma: less common (3%), more difficult to find and cure.
4. Medullary Thyroid Cancer (MTC) develops from C cells, generates calcitonin, and has the potential to spread before being discovered.
5. 2% of cases are Anaplastic thyroid cancer, aggressive, and frequently derived from other tumors that had already undergone differentiation.
6. Sarcoma, SCC, and Thyroid Lymphoma are uncommon and different from other thyroid cancers.
7. Parathyroid Cancer, uncommon cancer of the parathyroid glands results in elevated calcium levels, which can lead to symptoms like kidney stones, bone pain, and exhaustion. The main course of treatment is surgery.

A lump in the neck that may get bigger over time, neck pain or swelling, hoarseness or trouble speaking trouble swallowing or breathing, and a persistent cough that isn’t related to the flu or a cold are all signs of thyroid cancer.

Diagnosis and Management

Doctors can recommend an ultrasound if they find any tumors or anomalies in the thyroid during a physical examination to make the diagnosis. Finding out if a nodule is solid or filled with fluid might be aided by this imaging technique. Thyroid status can be determined via blood testing. Another technique that takes cells from a nodule for microscopic analysis is called fine-needle aspiration biopsy (FNAB).
Thyroid hormone therapy, radioactive iodine therapy, and surgery are available forms of treatment. For more advanced cases, external radiation or targeted therapy may be employed.

Prevention and Regular Screening

Thyroid nodules and cancer cannot always be avoided, but early identification and treatment can be aided by eating a diet high in iodine, limiting needless radiation exposure, and getting frequent checkups. Reduced consumption of white salt and preference for alternative salts, such as pink, etc., that are deficient in iodine, are among the factors contributing to the rise in thyroid cases.

(Dr. Manjunath Malige, Director – Diabetes & Endocrinology, Sakra World Hospital, Bengaluru)