Thyroid cancer often appears as a lump or nodule within the thyroid gland and usually does not cause any symptoms.
Blood tests are not helpful in diagnosing thyroid cancer, thyroid function tests such as TSH are usually normal. Physical examination is the most common way of detecting thyroid nodules and thyroid cancer. On physical examination, a single, firm nodule is usually palpated.
Thyroid nodules are usually detected incidentally by imaging methods such as neck ultrasound or tomography scans performed for other reasons. Sometimes it is found by chance by patients.
Thyroid cancers and nodules may rarely cause symptoms such as neck, jaw, or ear pain. If the nodule is large enough to press on the breath or esophagus, symptoms such as shortness of breath (dyspnea), difficulty swallowing (dysphagia), or a “tickling in the throat” may develop. More rarely, it can also cause hoarseness by pressing on the nerve that controls the vocal cords.
Although it is not known specifically why thyroid cancer develops, there are some identified risk factors: Thyroid cancers are more common in people who have a history of high-dose radiation exposure, have a family history of thyroid cancer, and are older than 40 years of age.
Diagnosis of thyroid cancer usually begins with palpation of a single, hard nodule on physical examination and evaluation of the patient’s history. Diagnosis is made by FNAB from the mass in the thyroid gland or lymph node.
The primary treatment for all thyroid cancer is surgery. The size of the thyroid tissue to be surgically removed for differentiated thyroid cancers will depend on the size of the tumor and whether the tumor is limited to the thyroid. Thyroid lobectomy surgery, in which only the lobe with the tumor is removed, is considered sufficient for cancers limited to the thyroid, very small (<1 cm) and without lymph node involvement.
On the other hand, total thyroidectomy is a better option if the tumor has spread to surrounding tissues or lymph nodes are involved. If the lymph nodes are involved by the disease at the time of first diagnosis (lymph node metastasis), a neck dissection is performed during the first thyroid surgery and the lymph nodes are also removed. If lymph node metastases occur later, it is necessary to remove the lymph nodes with an additional surgical intervention.
In recent studies, it has been suggested that small tumors called micropapillary thyroid cancers can be followed without surgery depending on their location in the thyroid.
After surgery, most patients will need to use thyroid hormone every day for the rest of their life. In addition, radioactive iodine therapy can be used after surgery in cases where the tumor is large, has spread to the lymph nodes, or has a high risk of recurrence.
Radioactive iodine therapy. (-131 treatment).
Thyroid cells and most differentiated thyroid cancers retain and concentrate iodine in it. Therefore, radioiodine can be used to remove all remaining normal thyroid tissue (radioactive iodine ablation) and to destroy any cancer cells that may potentially remain after thyroidectomy.
Because other tissues and cells in the body generally do not retain iodine, the radioactive iodine used during the ablation procedure usually has little or no effect on tissues other than the thyroid. However, in some patients receiving higher doses of radioiodine for the treatment of thyroid cancer metastases, the radioactive iodine may affect the salivary glands and cause complications such as dry mouth. There may be a slight increase in the risk of developing cancer in the long term when higher doses of radioactive iodine are used. Although this risk is high, it increases as the dose of radioactive iodine increases. It is important to balance the benefits of radioactive iodine therapy with the potential risks.
Thyroid hormone pills may need to be discontinued for 3-6 weeks before radioactive iodine treatment, as TSH levels need to be increased. In addition, you will need to follow a low-iodine diet for 1-2 weeks before treatment in order to increase the uptake of radioactive iodine and to maximize the treatment effect.
In general, the prognosis of differentiated thyroid cancer is excellent, especially for patients younger than 45 years of age and patients with a small tumor size. Patients with papillary thyroid cancer that has not protruded beyond the thyroid gland have an excellent prognosis. Ten-year survival for such patients is 100%, and death from thyroid cancer at any time thereafter is extremely rare. The prognosis for patients older than 45 years, patients with larger or more aggressive tumors is also very good, but the risk of cancer recurrence is higher. The prognosis may not be very good in patients whose cancer is more advanced, cannot be completely removed by surgery or completely removed with radioactive iodine therapy.