Silent Gland, Loud Impact: Understanding And Addressing Thyroid Cancer In Malaysia

KUALA LUMPUR, May 21 (Bernama) -- The thyroid gland, butterfly-shaped and often overlooked, sits at the base of the neck, quietly regulating metabolism, energy, and temperature.

But when cancer strikes this small organ, symptoms are often subtle until they’re not.

According to the Malaysia National Cancer Registry Report 2017-2021, thyroid cancer ranks as the 8th most common cancer among women, with an incidence rate of 4.2 per 100,000 population.

Often dubbed a silent disease, thyroid cancer can develop without obvious symptoms. In many cases, a persistent neck lump or subtle voice changes are the first signs.

While awareness has improved and more cases are now caught early through routine health screenings, confusion between thyroid cancer and common thyroid issues like hypothyroidism, goitre, and cancer continues to delay timely action.

In a statement today, Sunway Medical Centre (SMC), Sunway City Consultant Breast and Endocrine Surgeon Dr Wong Mei Wan, and SMC Consultant Nuclear Medicine Physician Dr Tan Heik Hin share their perspectives on the nature of thyroid cancer, from early signs and diagnosis to the modern treatment options available and the importance of long-term follow-up.

“The thyroid produces thyroxine, a hormone essential for metabolism. Too much makes you restless and energetic, too little and you feel sluggish and cold,” said Dr Wong.

However, thyroid cancer isn’t about hormones.

“Most patients with thyroid cancer have normal thyroid function. The cancer usually presents as a physical nodule in the thyroid gland. It does not typically cause hyperthyroidism or hypothyroidism and is not caused by them either,” Dr Tan clarified.

Unlike many other cancers, she said thyroid cancer in Malaysia is not strongly linked to lifestyle factors like smoking. Family history can be a factor.

“There are some hereditary types, but not every thyroid cancer is genetic. We only test when the family pattern is evident,” says Dr Wong. About two-thirds of her patients are women, which reflects a global trend.

Meanwhile, Dr Tan said early symptoms are often subtle, with many cases only detected when patients notice a persistent lump in the neck or experience voice changes, difficulty swallowing or swollen lymph nodes.

“Most thyroid cancers are detected at an early stage today, often through routine health screenings. A decade ago, we used to see more late-stage cases (stage 3 or 4). This shift is very encouraging,” he said.

Dr Tan noted that about 85 per cent of thyroid cancers are slow-growing and mainly consist of papillary or follicular types, which generally respond well to treatment. However, he cautioned that survival rates drop significantly once the disease spreads to distant organs.

“Once it reaches Stage 4 and spreads to the lungs or bones, survival falls to below 50 per cent,” he said.

On treatment pathways, Dr Tan said that treatment typically begins with surgery to remove the tumour, followed in higher-risk cases by radioactive iodine (RAI) therapy, which targets residual cancer cells and helps detect any remaining disease.

“RAI serves both treatment and diagnostic purposes. It clears out any leftover cancer cells and lets us scan for hidden spread. RAI is chemically identical to iodine in the body. It is safe, well-tolerated and rarely causes allergies, and not comparable to external beam radiation therapy,” he said.

While prognosis is generally favourable, both specialists stressed the importance of long-term monitoring, as recurrence can occur years after treatment, often in the lymph nodes.

Dr Wong noted that patients who undergo a total thyroidectomy usually require lifelong thyroid hormone replacement therapy, which functions similarly to daily supplements to maintain the body's metabolic balance.

To ensure early detection of any recurrence, Dr Tan recommends that early-stage patients undergo follow-up medical evaluations every six months for the first two years, then annually for up to five years.

He added that newer targeted therapies, such as tyrosine kinase inhibitors (TKIs), are also available, providing critical treatment options for advanced or treatment-resistant cases where radioactive iodine therapy is no longer effective.

“These are used when RAI is no longer effective. They shrink tumours before surgery or manage metastatic disease,” he said, while noting that patients must be monitored closely for potential side effects such as fatigue, skin problems, proteinuria and hypertension.

Both doctors agreed that while thyroid screening is not routine in Malaysia, public education remains vital.

“If you feel a persistent lump in your neck, don’t wait to get it checked. An ultrasound and blood test are simple, accessible, and can be done at most clinics,” added Dr Wong. 

-- BERNAMA