A number of factors affect the prognosis for papillary and follicular thyroid cancers. A better prognosis can be expected with a pure papillary carcinoma in younger patients (women under 50 and men under 40), a tumor smaller than 2 cm (¾ in.), no distant metastases, female sex and low-grade lesions.
A worse prognosis is related to age over 40, the degree of invasion (vascular and thyroid capsule) in follicular carcinoma, distant metastasis , a large tumor (especially over 5 cm/2 in.), large nodular metastases, male sex and high-grade lesions (aneuploid).
Surgery The primary treatment of thyroid cancer is surgery, but there are some differences in
opinion about the extent of thyroid resection required for the best prognosis. A near-total thyroidectomy—removing almost all the thyroid— offers the best chance for cure, especially if the cancer is in several places within the gland. The removal of all functioning thyroid tissue also makes it possible to scan for metastatic disease with radioactive iodine and to use serum thyroglobulin values to detect persistent disease.
One of the risks of a total thyroidectomy is the inadvertent removal of the parathyroid glands, which are situated, two on each side, at the edge of the thyroid. When a total thyroidectomy is done, an attempt is usually made to leave all four parathyroid glands in place. The surgeon must maintain an adequate supply of blood to the parathyroid glands to prevent the symptoms and signs of hypoparathyroidism or parathyroid hormone deficiency. Thyroid operations also have some risk of damage to the nerves in the neck that supply the larynx (voice box).
