Follicular thyroid cancer (FTC) accounts for about 10% to 15% of all thyroid cancers. It is more common in iodine-deficient areas and often occurs in middle-aged and older adults in their 50s. The causes may include low iodine intake, radiation therapy to the head and neck, or exposure to high levels of ionizing radiation.
Symptoms
Usually an asymptomatic nodule or mass in the neck. The mass tends to grow progressively larger with poorly defined borders, and later may show symptoms of local organ compression or invasion such as hoarseness and difficulty breathing.
Clinical features
FTC is a differentiated type of thyroid cancer with relatively low malignancy. Compared with papillary thyroid carcinoma (PTC), the other most common differentiated type of cancer, it is less likely to have lymph node metastases (FTC: approximately 10% to 20%; PTC: 30% to 60%) and more likely to have hematologic metastases (FTC: 7% to 28%; PTC: 1%-4% occurring at initial diagnosis and 2.5%-5% after initial surgery), often metastasizing to lung and bone. Once extensive metastases occur, mortality may reach 50%.
Staging and treatment
The staging of FTC is age-dependent, with a “watershed” age of 55 years, with patients under 55 years of age usually having a more optimistic outcome and being staged as stage I or II, and those over 55 years of age being staged as stage I-IV.
If you want to know exactly how it is staged, click below:
The standard treatment of differentiated thyroid cancer is mainly surgery, and the subsequent treatment plan is determined by tumor stage and risk of recurrence after surgery, which consists of the following three parts:
- Surgical resection of the primary site and potentially resectable metastatic lesions.
- A subset of patients require radioactive iodine (RAI) therapy to destroy residual thyroid tissue after surgery and occult or inoperable metastatic lesions.
- Most patients need to take thyroid hormone pills for life to replenish thyroxine and inhibit tumor recurrence and growth.
If you would like more information about the above treatments, please click below:
Co-written by Dr. Kai Qian, Fudan University Cancer Hospital Dr. Kai Guo