Thyroid cancer may have a low incidence rate worldwide but here in the Philippines it is the 7th leading form of cancer among Filipinos with an estimated 3,024 new cases in 2012.
According to the World Health Organization’s International Agency for Research, in 2012 the country has recorded at least 865 deaths due to thyroid cancer, which accounts for the 1.5 percent of cancer related deaths, and in five years new thyroid cancer cases will reach to 11,280 each year.
Though it can occur in any age group, thyroid cancer is most common among women between 20 to 44 years old. It is three times more common in females than in males and its aggressiveness significantly increases at age 30 and in older patients1.
Importance of early diagnosis and treatment
Thyroid cancer is a malignant growth of tumor in the thyroid gland. The thyroid is a small, butterfly-shaped gland located at the front of the neck right below the throat. The thyroid gland secretes thyroxine, a hormone responsible for the regulation of metabolic rate, blood sugar, heartbeat and renal functions.
According to the Thyroid Cancer Association, Inc., (TCAI), “Many patients, especially in the early stages of thyroid cancer, do not experience symptoms. However, as the cancer develops, symptoms can include a lump or nodule in the front of the neck, hoarseness or difficulty speaking, swollen lymph nodes, difficulty swallowing or breathing, and pain in the throat or neck.”
Although thyroid cancer is generally slow-growing and curable,2,3 up to 30% of patients can still experience recurrence4. Together with early diagnosis and appropriate treatment, life-long compliance to follow-up is critical to detect persistent and recurrent disease.5
There are different types of thyroid cancer, the most common being the Papillary variant, which accounts for around 80% of cases. The other types are Follicular (around 10% of cases), Medullary (around 4%) and Anaplastic (2%).
The primary treatment for thyroid cancer is thyroidectomy, which is the surgical removal of the thyroid gland.
After the removal of the thyroid, to effectively wipe out remnants of cancer tissues and any other thyroid gland tissue, doctors usually advise radioactive iodine (RAI) treatment.
To effectively monitor for persistence and recurrence of disease, patients undergo follow-up using Thyroglogulin (Tg) blood tests, neck ultrasound tests and diagnostic RAI whole-body scans.6
It must be noted that since patients already have the thyroid gland removed, the body will no longer produce thyroid hormones, hence patients will need thyroid hormone replacement therapy with levothyroxine to prevent hypothyroidism for the rest of their lives, in order to compensate for the loss of thyroxine in their bodies.7
However, in preparation for procedures involving RAI (treatment and diagnostic whole-body scan), doctors require patients to undergo thyroid hormone withdrawal (THW), or the suspension of levothyroxine, in order to elevate levels of thyroid stimulating hormone or TSH. Elevated levels of TSH enables effective absorption of RAI in the thyroid bed. RAI destroys remnant tissues and is useful in monitoring for cancer tissue recurrence THW for patients usually takes 4-6 weeks.5
With the absence of a national consensus across the different healthcare professionals involved in thyroid cancer management, approaches in the care of patients vary per institution and per clinic. Hence, standardized and optimized treatment might not be offered to all thyroid cancer patients.
Symptoms to watch out for during THW9
Aside from health consequence, hypothyroidism may affect a patient’s life in different ways —work performance, decision making, self-image, social activities, and the long term effect on the patient’s body.
The most common symptoms to watch out for are:
– Less energy, fatigue
– Cold intolerance
– Drier skin and coarser hair
– Mild weight gain (5-20 lbs)
– Puffiness around the face (especially the eyes), hands, ankles, due to fluid build up
– Slower mental function, irritability
– New or worsening depression
– Slowing of heart rate
– Slightly higher blood pressure
– Higher cholesterol levels
Hypothyroidism does not just cause symptoms; it can make other health conditions worse.
To avoid the consequences of hypothyroidism, patients have the option to use synthetic TSH* to keep them on levothyroxine thus preventing the symptoms and complications caused by hypothyroidism4,5,10. The effect of synthetic TSH is the same as the natural elevation of TSH following THW. It can stimulate remnant thyroid cells (whether normal or malignant) and to absorb iodine that is found in the blood stream, including RAI.11
*Synthetic TSH is a prescription medicine which can only be given by a doctor after assessments are done to patients in order to determine disease condition, suitability and other relevant factors.