CLINICAL THYROIDOLOGY FOR PATIENTS
A publication of the American Thyroid Association
Only a few thyroid cancer patients have a cancer recurrence within 8 years of initial therapy
ABBREVIATIONS & DEFINITIONS
Papillary thyroid cancer: the most common type of thyroid cancer.
Papillary microcarcinoma: a papillary thyroid cancer smaller than 1 cm in diameter
Thyroglobulin: a protein made only by thyroid cells, both normal and cancerous. When all normal thyroid tissue is destroyed after radioactive iodine therapy in patients with thyroid cancer, thyroglobulin can be used as a thyroid cancer marker in patients that do not have thyroglobulin antibodies.
Radioactive iodine (RAI): this plays a valuable role in diagnosing and treating thyroid problems since it is taken up only by the thyroid gland. I-131 is the destructive form used to destroy thyroid tissue in the treatment of thyroid cancer and with an overactive thyroid. I-123 is the non-destructive form that does not damage the thyroid and is used in scans to take pictures of the thyroid (Thyroid Scan) or to take pictures of the whole body to look for thyroid cancer (Whole Body Scan).
Cancer recurrence: this occurs when the cancer comes back after an initial treatment that was successful in destroying all detectable cancer at some point.
Thyroid cancer is the fastest rising cancer in women and the most common type of thyroid cancer is papillary cancer. The majority of patients with papillary thyroid cancer do well after the treatment which includes surgery and often radioactive iodine therapy. While only a small number of patients with papillary cancer die from their cancer, recurrence of the cancer is relatively common and patients are followed for many years for recurrence of the cancer. However, it is not clear how long and how often patients with papillary cancer need a follow up. This study was done to find out the time and rate of recurrence in patients with papillary thyroid cancer to improve the management of these patients.
THE FULL ARTICLE TITLE:
Durante C et al, Papillary thyroid cancer: time course of recurrences during postsurgery surveillance. J Clin Endocrinol Metab 2013;98:636-42. Epub January 4, 2013.
SUMMARY OF THE STUDY
This study looked at 2010 patients with papillary cancer seen at 8 Italian Centers between 1990 and 2012. In all patients, the entire thyroid was removed by surgery and radioactive iodine was performed in 88% of patients. Yearly follow up included ultrasound and blood tests for thyroglobulin. The average size of the cancer was 15 mm. More than one cancer in the thyroid was found in 1/3rd of patients. Extension of cancer outside of the thyroid was found in 245 patients and spread of cancer to the lymph nodes in the neck in 255 patients. A total of 61.3% of patients were classified as low risk, 35.5% were intermediate risk and 3.2% were high risk.
During the first year after surgery 72 (7%) of the patients had persistent cancer. Only 2.5% of 625 low risk patients had persistent cancer as compared to 11.3% of the 362 patients with intermediate risk and 69.7% of the 33 patients with high risk. During 8 years of follow up, cancer recurrence was found only in 13 (1.4%) of the 948 patients considered to be disease-free after surgery and half of them recurred during the first 3 years. Of these 13 patients, 5 were low-risk and 8 were intermediate-risk patients.
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study shows that cancer recurrence is very low in patients with papillary thyroid cancer that are classified as low or intermediate risk. These patients can likely be followed less often. However, high-risk patients still need more frequent careful follow up.
— Jamshid Farahati, MD
ATA THYROID BROCHURE LINKS
Thyroid cancer: http://www.thyroid.org/cancer-of-the-thyroid-gland
Radioactive Iodine Therapy: http://www.thyroid.org/radioactive-iodine
Thyroid Surgery: http://www.thyroid.org/patients/patient_brochures/surgery.html