Answering The ‘Why’ Of Thyroid Cancer and Treatment Options

When cancer strikes, the question on many people’s minds is, “why me?”. Thyroid cancer, like many cancers, is complex. As World Thyroid Day approaches on the May 25th, this is an opportune moment to shed light on what affects thyroid health.

Talking Thyroid

The thyroid is a small gland located at the base of the neck, and it forms part of our endocrine system. It refers to the glands that produce hormones to regulate our metabolism, growth, and development. Furthermore, these glands are responsible for our tissue function, sexual function, reproduction, sleep, and even our mood.

“The thyroid, as small as it is, is crucial” says Dr Fatima Hoosain, a specialist surgeon in a super- specialist breast and thyroid health centre.

“It affects, directly or indirectly, almost every function in our bodies. The thyroid releases two important hormones into our bloodstream, triiodothyronine (T3) and tetraiodothyronine (T4). These hormones are produced with iodine, which is derived from the foods we eat and is a necessary constituent of our diets.”

What might contribute to thyroid dysfunction and cancer?

Environmental factors such as exposure to endocrine-disrupting chemicals (EDCs) like bisphenols, phthalates, and perchlorate can interfere with thyroid hormone synthesis, release, and action. They can also mimic or disrupt thyroid function and lead to potential health issues[1].

Bisphenol A (BPA) is found in food packaging, plastic bottles, and the lining of canned foods. BPA can mimic oestrogen in the body, raising concerns about its potential health effects[2].  Phthalates are chemicals used to make plastics more flexible and are commonly found in cosmetics, food packaging, and household items. Research suggests that prolonged exposure may interfere with hormone function, potentially affecting reproductive health[3].  Perchlorate is a chemical found in fireworks, bleach, and contaminated water and primarily impacts thyroid health by interfering with iodide uptake, potentially leading to reduced thyroid hormone production.

“There are ways to minimise your exposure to EDCs,” says Hoosain. “BPA-free food packaging and containers are available in some countries. BPA has been banned in baby bottles in this country, and most domestically manufactured plastic food packaging is also BPA-free. You can also look for phthalate-free labelling on cosmetics, personal care items and household products, limit the excessive use of bleach and filter your water,” she advises.

Your thyroid and you

Lifestyle choices such as diet, exercise, and stress management play a role in maintaining thyroid function. Chronic stress can impact thyroid hormone levels and exacerbate thyroid disorders. Says Hoosain:

“A diet low in pro-inflammatory foods, such as added sugars and ultra-processed foods; may be beneficial for hypothyroidism. Consuming foods rich in iodine, selenium, zinc, vitamin B12, magnesium, and iron also supports thyroid health. Stress in today’s world is multi-faceted and stress relief tools such as exercise, meditation and prioritizing work-life balance are important, not only for the thyroid but for overall health.”

Like many cancers, thyroid cancer can have a genetic component. People with a family history of thyroid cancer, particularly medullary thyroid cancer, or the rare pheochromocytoma tumor (a tumor that develops in the adrenal gland)), have higher chances of developing thyroid cancer. As in the case of breast cancer, a genetic test can be advised in selected individuals to determine if the patient carries genes that increase the potential risk of having the disease. Furthermore, risk reduction options are available if a mutation is found in the RET gene.

Treating thyroid cancer

The choice of treatment depends on the type of thyroid cancer, the size of the cancer, the patient’s age, and whether the cancer has spread to lymph nodes or other organs.

“Surgery is generally the main treatment for thyroid cancer. Thyroid cancer is diagnosed by using a combination of a fine needle biopsy and ultrasound. Surgery to remove half or all of the thyroid gland is recommended if the diagnosis is confirmed. Except for medullary and anaplastic thyroid cancers, it is rare for thyroid cancers to require more aggressive treatments such as radiation and chemotherapy. Biologicals are reserved for patients with metastatic disease or who do not respond to radioactive iodine therapy,” says Hoosain.

Most thyroid cancers behave similarly to normal thyroid tissue, which can be exploited by adding radioactive iodine to the treatment plan. The iodine concentrates in the cancer cells and slowly destroys them. “The slow growth of most thyroid cancers also means that if treated properly, they have an excellent prognosis,” explains Hoosain.

Longe term treatment

Long-term treatment consists of administering thyroid hormones in the form of pills to replace the function of the removed thyroid gland and to suppress growth of residual thyroid tissue. However, this too is individualized and is reserved for patients who have had their entire thyroid removed.

According to Hoosain, once the primary treatment is completed, the vast majority of patients will lead a normal life.

“Follow-up consists of annual visits to the doctor for a physical examination, an ultrasound of the neck and blood tests to check for thyroid hormone levels and markers for recurrent cancer,” she adds.

Takeaway

Thyroid cancer is relatively rare, but it is still one of the more common cancers, and early diagnosis and treatment are crucial for better survival chances. It is also important to note that while thyroid dysfunction is fairly common, diseases of the thyroid are rarely cancerous and can usually be well-managed. These functional abnormalities include hypothyroidism (lack of thyroid hormones secreted) and hyperthyroidism (increase in thyroid hormones secreted).

References

[1]  [Silent Disruptors: How Environmental Chemicals Threaten Thyroid Health] (https://endocrinenews.endocrine.org/silent-disruptors-how-environmental-chemicals-threaten-thyroid-health-and-development/)

[2]  [Bisphenol A (BPA) – National Institute of Environmental Health Sciences] (https://www.niehs.nih.gov/health/topics/agents/sya-bpa)

[3] [Are Phthalates Safe? – Cleveland Clinic Health Essentials] (https://health.clevelandclinic.org/what-are-phthalates)