Understanding thyroid cancer
Thyroid cancer may have a low incidence rate worldwide but in the Philippines, it is the seventh 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. In five years, new thyroid cancer cases will reach 11,280 each year.
Though it can occur in any age group, thyroid cancer is most common among women between 20 and 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 patients.
Thyroid cancer is a malignant growth of tumor in the thyroid gland. The thyroid is a small, butterflyshaped 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.”
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 the disease, patients undergo follow-up using Thyroglogulin (Tg) blood tests, neck ultrasound tests, and diagnostic RAI whole-body scans.
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.
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 the thyroid-stimulating hormone or TSH. Elevated levels of TSH enable effective absorption of RAI in the thyroid bed. RAI destroys remnant tissues and is useful in monitoring cancer tissue recurrence. THW for patients usually takes four to six weeks.
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.
The most common symptoms to watch out for are: physical — 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 buildup; mental— slower mental function, irritability, new or worsening depression; cardiovascular — 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 hypothyroidism. 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.
Synthetic TSH is a prescription medicine which can only be given by a doctor after assessments are done on patients in order to determine the disease condition, suitability, and other relevant factors.