Reprinted with permission from Dr. Rubenfeld's book Could It Be My Thyroid?
2nd edition, 2002, copyright 1996 and 2002 by Sheldon Rubenfeld.
3rd edition available through bookstores early in 2004.
The outlook for patients with papillary or follicular thyroid cancer is very good. In general, patients with papillary cancer, the most common type of thyroid cancer, have a better prognosis than patients with follicular cancer have. With the appropriate treatment, more than 90% of all patients will be cured.
While cure rates have been determined for groups of patients with papillary or follicular thyroid cancer, it is nearly impossible to predict the outcome for an individual patient….Nonetheless, medical scientists have made several attempts either to predict the prognosis of patients with differentiated thyroid cancers or to classify these patients into low- or high-risk categories.
A patient’s prognosis is determined by multiple factors. The most important patient factor is age, although gender is also important. The most important characteristics of the cancer are size, type, extent of local invasion, and distant metastasis, although the number of tumors in the thyroid gland also influences the patient’s prognosis. For example, the risk of a thirty-five-year-old woman dying from a papillary cancer smaller than 1.0 centimeter (occult thyroid cancer, or microcarcinoma) is very low. On the other hand, the risk of death is increased for a sixty-five-year-old male with a 5-cm (centimeter) follicular cancer that has extended beyond the thyroid gland.
A patient’s prognosis determines, in large part, the extent of surgery and the follow-up treatment. For example, a thirty-five-year-old woman with a papillary cancer smaller than 1.5 cm may have only a lobectomy and isthmusectomy as opposed to a subtotal or total thyroidectomy since the prognosis for such a patient is excellent. On the other hand, a sixty-five-year-old man with a 5-cm follicular cancer will have either a subtotal or total thyroidectomy followed by radioactive iodine. Once again, each patient must be treated individually, taking into account both the prognosis and the patient’s personal preferences.
Although it would be ideal to classify a patient into either a low-risk or a high-risk category for the purposes of determining an accurate prognosis and the proper treatment, it is not always possible to do so. A low-risk patient with a high-risk cancer (for example, a thirty-five-year-old woman with a 5-cm follicular cancer and distant metastases) or a high-risk patient with a low-risk cancer (for example, a fifty-five-year-old man with a 3-cm papillary cancer without distant metastases) may fall into an intermediate-risk group. The outcome of this group is less favorable than the low-risk group but better than the high-risk group. When it is possible, classifying a patient into a risk group is useful in deciding how aggressive to be with surgery and other treatments.
Favorable Prognostic Factors for Patients with Differentiated Thyroid Cancers
- age less than 45
- tumor size less than or equal to 4 cm
- papillary cancer, including follicular variant, with well-defined capsule
- follicular cancer with minimal imvasion of the capsule
- absence of local invasion
- absence of blood vessel invasion
- absence of lymph node metastasis
- absence of distrant metastasis
- single thyroid cancer
- female gender
- presence of Hashimoto’s thyroiditis
Less Favorable Prognostic Factors for Patients with Differentiated Thyroid Cancer
- age 45 or greater
- papillary cancer with anaplastic transformation
- poorly differentiated follicular cancer
- tall-cell, columnar, or diffuse sclerosing variants of papillary cancer
- Hurthle cell type
- distant metastasis
- local invasion
- blood vessel invasion
- multiple papillary cancers (multifocal papillary cancer)
- insufficient surgery
- delay in therapy
- no levothyroxine therapy
- no radioactive iodine treatment in some patients
- male gender
- presence of Graves’ disease
Last updated: October 23, 2006