Click here for Frequently Asked Questions on the Treatment of Thyroid Cancer.
A surgical procedure is required for the treatment of patients with thyroid cancer. The extent of surgery will depend on the suspected pathological diagnosis and the size of the nodule (putative tumor), and is often influenced by the results of the preliminary tumor analysis intra-operatively during a 'quick-section' analysis of tumor histology. The nature and extent of thyroid surgery for thyroid cancer may vary from center to center and should be discussed prior to surgery with an experienced thyroid surgeon. Patients should be aware that a diagnosis made at quick section is not always accurate. It is uncommon for a diagnosis of benign adenoma to be made at quick section, only to have the final pathology report come back as thyroid cancer. In such instances, an additional operation may then be required to remove the remaining thyroid tissue.
Complications and risks of removing most of the thyroid (subtotal thyroidectomy) include the risks of general anesthesia, damage to local nerves, including the recurrent laryngeal nerve that innervates the vocal cords, and hypocalcemia (low levels of calcium in the blood), if extensive damage to or resection of all 4 parathyroid glands occurs. In some instances, a search for lymph nodes surrounding the thyroid may also be carried out (lymph node dissection). As is the case with many surgical procedures, the experience of the thyroid surgeon will greatly influence the complication rate during surgery. Wherever possible, patients are advised to seek a surgeon with extensive experience in thyroid surgery. Depending on the type of operation, stay in hospital may range from several hours to a few days. In many centers, patients undergoing a partial or hemi-thyroidectomy, may be discharged home several hours after the surgical procedure. In contrast, patients undergoing more extensive surgery may be hospitalized for several days, especially if hypocalcemia (low calcium) develops postoperatively. For more information, see the section on Thyroid Surgery.
Radioactive iodine is often administered to ablate or destroy the few normal remaining normal thyroid cells that were not removed at the time of surgery. Radioactive iodine may also destroy any remaining clusters of thyroid cancer cells. The amount of radioactive iodine administered depends on the type and size of tumor, the initial extent of surgery, and the presence or absence of suspected residual tumor. In some instances, radioactive iodine for thyroid remnant ablation may be administered as an outpatient. In other treatment indications or regimens, patients may be administered a somewhat larger radioactive iodine dose that may require hospitalization for 48-72 hrs or so, depending on the dose administered.
Following surgery and radioactive iodine treatment, patients will usually take thyroid hormone in the form of thyroxine in a dose sufficient to keep their TSH level in the suppressed range. Thyroid cancer may present and be treated somewhat differently in children Childhood Thyroid Cancer Treatment (PDQ®): Health Professional Version PDQ Cancer Information Summaries [Internet]. Bethesda (MD): National Cancer Institute (US); 2002-. 2019 Aug 16
I have a small thyroid cancer less than 10 mm in size. Does it have to be treated?
Most thyroid cancer experts would recommend traditional treatment involving at least surgical removal of the thyroid gland. However, some patients have elected not to be treated and have been followed by their physicians. It appears that many patients with very small thyroid cancers will have minimal growth of the small thyroid cancers over several years observation, however there is no scientific randomized clinical trial data available to support decision making in this area. See An observation trial without surgical treatment in patients with papillary
microcarcinoma of the thyroid. Thyroid. 2003 Apr;13(4):381-7.
Although the prognosis is clearly excellent for patients with small
tumors, the required extent of surgery and the potential need for
radioactive iodine has not been clearly defined in randomized studies Papillary
thyroid microcarcinoma (PTMC): Prognostic factors, management and
outcome in 403 patients. Eur
J Surg Oncol. 2006 Jul 25; [Epub ahead of print]. However
patients with small tumors confined to the thyroid appear to do well
independent of whether they receive radioactive iodine, as outlined in Outcomes
of patients with differentiated thyroid carcinoma following initial
2006 Dec;16 (12):1229-42. Interestingly, although lymph node
involvement may be detected in 305 of patients with microcarcinomas less
than 10 mm in size, the prognosis for patients with small tumors is
generally excellent, irrespective of the extent of initial surgery or the
use of radioactive iodine Papillary
thyroid microcarcinoma: a study of 900 cases observed in a 60-year period Surgery.
I have heard that some less well differentiated more aggressive thyroid tumors that don't take up radioactive iodine can be treated with Vitamin A?
A subset of tumors appear to respond to the class of drugs known as retinoids. In some studies, patients treated with Patients with advanced thyroid cancer and without the therapeutic options of operation or radioiodine therapy were treated with 13- cis-retinoic acid at a dosage of 1.5 mg/kg body weight daily appear to show a response, with tumor regression and in some cases, increased radioactive iodine uptake by the tumors. A response was detected in about 38 % of cases in a pilot study over 5 weeks. See Clinical impact of retinoids in redifferentiation therapy of advanced thyroid cancer: final results of a pilot study. Eur J Nucl Med Mol Imaging. 2002 Jun;29(6):775-82. Subsequent observational studies of larger patients have shown less impressive results using this type of "differentiation therapy" as shown in Retinoic acid for redifferentiation of thyroid cancer - does it hold its promise? Eur J Endocrinol. 2003 Apr;148(4):395-402.
Has the outcome and survival statistics for well differentiated thyroid cancer (WDTC) changed over the last few years?
A study at the Mayo clinic documents trends in the diagnosis, treatment and outcome of patients with WDTC. The prognosis for this disease was excellent in most patients several decades ago, and remains comparably favorable over recent years. See Papillary Thyroid Carcinoma Managed at the Mayo Clinic during Six Decades (1940-1999): Temporal Trends in Initial Therapy and Long-term Outcome in 2444 Consecutively Treated Patients. World J Surg. 2002 May 21.
I had thyroid cancer in my lymph nodes-what does this mean?
For many younger patients less than 45 years of age, the presence of well-differentiated papillary thyroid cancer in local lymph nodes in the neck does not change the excellent prognosis associated with this disease as outlined in The impact of lymph node involvement on survival in patients with papillary and follicular thyroid carcinoma Surgery. 2008 Dec;144(6):1070-7
Is it always necessary to have surgery for cancer in the lymph nodes?
Traditional initial treatment of thyroid cancer has involved removal of half or the entire thyroid gland, with removal of any lymph nodes that appear suspicious at the time of initial surgery, and consideration of radioactive iodine for patients with cancer in lymph nodes. Subsequent detection of thyroid cancer (residual or recurrent disease) in lymph nodes has usually been treated by surgical removal of the lymph nodes; emerging reports suggest that ultrasound-guided injection of the cancerous lymph nodes with alcohol may be an effective treatment in reducing thyroglobulin levels and decreasing the size and presence of cancer cells in lymph nodes for many patients with isolated lymph node recurrence. However, the mean follow-up of patients in one Norwegian study was just over 3 years, hence we do not yet have long term data informing us about the efficacy or safety of this approach. Efficacy of ultrasound-guided percutaneous ethanol injection treatment in patients with a limited number of metastatic cervical lymph nodes from papillary thyroid carcinoma J Clin Endocrinol Metab. 2011 Sep;96(9):2750-5
I have only had half my thyroid removed and the pathology report showed cancer. Do I need to have a second operation or can radioactive iodine be used in my situation?
The answer to this question is a matter of some debate. If the pathology report shows a large tumor, with aggressive features such as lymph node involvement, most physicians would strongly recommend completion thryoidectomy and removal of the remaining thyroid lobe. On the other hand, if the pathology shows a small well differentiated thyroid cancer, there is some evidence that low dose outpatient radioactive iodine can be used to ablate the remaining thyroid lobe, as outlined in Radioactive iodine lobe ablation as an alternative to completion thyroidectomy for follicular carcinoma of the thyroid. Thyroid. 2002 Nov;12(11):989-96.
What stage is my thyroid cancer?
There are various staging or classification systems used by different experts, some of which are reproduced below. Note that even with the use of these staging systems, there may be tremendous variability in assigning a meaningful classification-for example, see one study describing the different prognostic implications of macroscopic vs. microscopic extrathyroidal tumor extension; Extrathyroidal extension is not all equal: Implications of macroscopic versus microscopic extent in papillary thyroid carcinoma Surgery. 2008 Dec;144(6):942-7
T - primary tumor
T0 - no palpable tumor
T1 - single tumor confined to the gland; no deformity
T1 - multiple tumors confined to the gland; no deformity
T2 - multiple tumors or a single tumor producing deformity of the gland
T3 - tumor extending beyond the gland
N - regional lymph nodes
N0 - no palpable nodes
N1 - movable homolateral nodes
N2 - movable contralateral or bilateral nodes
N3 - fixed nodes
M - distant metastases
M0 - no evidence of distant metastases
M1 - distant metastases present
|Clinical Stage||TNM Classification|
|I: Intrathyroidal||T0, T1, T2, N0, M0|
|II: Cervical adenopathy (lymph nodes)||T0--T2, N0--N2, M0|
|III: Locally invasive disease||T3, N3, M0|
|IV: Distant metastases (cancer spread outside neck)||M1|
(Only applicable for papillary cancer)
Large retrospective studies have been carried out and analyzed statistically. One of these studies emanates from the Mayo Clinic (Predicting outcome in papillary thyroid carcinoma: development of a reliable prognostic scoring system in a cohort of 1779 patients surgically treated at one institution during 1940 through 1989. Surgery. 1993 Dec;114(6):1050-7;).
M stands for metastasis, A for Age, C for complete resection, I for invasive and S for Size.
|M||+ 3 if Metastasis is found|
|A||<= 39 years of age = 3.1. = 40 = Age (y) x 0.08|
|C||+ 1 if resection is inComplete|
|I||+ 1 if Invasive growth (pathologists report)|
|S||0.3 x largest diameter in centimeters (Size)|
|Prognostic score||20 year survival|
|< 6||99 %|
|6 - 6||89 %|
|7 - 8||56 %|
|> 8||24 %|
Thyroid cancer is viewed as a disease of younger people. Can older individuals get thyroid cancer also?
Thyroid cancer is not uncommon in older patients. In one study, subset analysis of thyroid cancer presentation and outcomes suggested that the disease presents with similar features in older patients, with a slightly higher rate of metastatic disease at the time of initial diagnosis. See Long-term results in elderly patients with differentiated thyroid carcinoma. Cancer. 2003 Jun 1;97(11):2736-42.
Are there therapies available for patients with disease that is poorly responsive to radioactive iodine?
There are a number of trials underway designed to test new agents. For example, see a study of the investigational agent Motesanib diphosphate in the treatment of differentiated thyroid cancer Motesanib diphosphate in progressive differentiated thyroid cancer N Engl J Med. 2008 Jul 3;359(1):31-42. The MD Anderson cancer center experience with newer agents for the treatment of thyroid cancer was published in January 2013 The Noninvestigational Use of Tyrosine Kinase Inhibitors in Thyroid Cancer: Establishing a Standard for Patient Safety and Monitoring J Clin Endocrinol Metab. 2013
An updated overview of new targeted therapies for thyroid cancer is found here Targeted Therapy for Advanced Thyroid Cancer: Kinase Inhibitors and Beyond Endocrine Reviews, Volume 40, Issue 6, December 2019, Pages 1573–1604
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