Papillary thyroid cancer is the most frequently diagnosed form of thyroid cancer, accounting for approximately 75% to 85% of all thyroid cancer cases. This type of cancer originates in the follicular cells of the thyroid gland, which is a butterfly-shaped organ located at the base of the neck. It is considered a differentiated cancer, meaning its cells resemble normal thyroid cells.
About Papillary Thyroid Cancer
Papillary thyroid cancer is known for its generally slow-growing nature and often remains localized within the thyroid gland. While it can occur at any age, it is more commonly observed in individuals between 20 and 55 years old, and it affects women about three times more often than men. Despite its tendency to spread to nearby lymph nodes in the neck, it typically responds well to treatment.
Risk factors for developing papillary thyroid cancer include exposure to significant ionizing radiation, particularly during childhood. This exposure could stem from therapeutic radiation treatments or environmental incidents, such as nuclear fallout. A family history of thyroid cancer or certain inherited conditions, like familial adenomatous polyposis, also slightly increases an individual’s risk, although most patients do not have identifiable risk factors.
Detection and Diagnosis
Papillary thyroid cancer often does not cause noticeable symptoms in its early stages and is frequently discovered incidentally during routine physical examinations or imaging tests performed for other health concerns. When symptoms do appear, they may include a painless lump or swelling in the front of the neck, sometimes accompanied by hoarseness or difficulty swallowing if the tumor is large enough to press on the windpipe or esophagus. Enlarged lymph nodes in the neck can also be a sign.
The diagnostic process typically begins with a physical examination of the neck, followed by imaging tests such as an ultrasound of the thyroid gland. Ultrasound helps determine if a nodule is solid or fluid-filled, with solid nodules having a higher chance of being cancerous. While blood tests to assess thyroid hormone levels are usually performed, thyroid function often remains normal in individuals with thyroid cancer.
The definitive diagnosis of papillary thyroid cancer is made through a fine needle aspiration (FNA) biopsy. During an FNA, a thin, hollow needle is inserted into the thyroid nodule, often guided by ultrasound, to collect a small sample of cells. These cells are then examined under a microscope by a pathologist to identify cancerous changes.
Treatment Options
The primary treatment for papillary thyroid cancer is surgery, with the specific type depending on the tumor’s size, spread, and other individual factors. A total thyroidectomy, which involves removing the entire thyroid gland, is a common approach, especially for larger tumors, cancer in both lobes, or when cancer has spread beyond the thyroid. In some cases, for very small, low-risk tumors confined to one side of the thyroid, a thyroid lobectomy (removal of half the thyroid) may be an option. If cancer cells are found in nearby lymph nodes, a neck dissection to remove these nodes is also performed.
Following surgery, radioactive iodine (RAI) therapy may be recommended, particularly if there is a risk of remaining cancer cells or spread. This treatment involves swallowing a capsule with radioactive iodine. Thyroid cancer cells can absorb iodine, allowing radioactive iodine to target and destroy residual thyroid tissue or cancer cells throughout the body.
External beam radiation therapy is less common for initial papillary thyroid cancer treatment but may be considered for larger, aggressive cancers or those that have spread to nearby tissues and are not responsive to RAI. For very low-risk cases, particularly small tumors, active surveillance may be an alternative to immediate surgery. This approach involves regular monitoring with ultrasounds to watch for any changes, delaying surgery unless the tumor shows signs of growth or progression.
Life After Diagnosis
Papillary thyroid cancer generally carries an excellent prognosis, with high survival rates, especially when localized. The five-year survival rate for localized cancer is nearly 100%.
Long-term management involves regular follow-up care to monitor for any signs of recurrence. This typically includes periodic blood tests to measure thyroid-stimulating hormone (TSH) and thyroglobulin levels, which can indicate the presence of remaining thyroid tissue or cancer cells. Imaging tests, such as neck ultrasounds, are also part of the routine follow-up.
After a total thyroidectomy, individuals will need to take thyroid hormone replacement therapy, usually in the form of levothyroxine, for the rest of their lives. This medication replaces hormones the thyroid gland no longer produces, maintaining normal metabolism and potentially reducing recurrence risk by suppressing TSH levels. Dosage is adjusted to individual needs.