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thyroid carcinoma

Etiology: 1) papillary thyroid carcinoma (most common, 75-85%) 2) follicular thyroid carcinoma (10-20%) 3) oncocytic thyroid carcinoma (3%) 4) medullary thyroid carcinoma 5) anaplastic thyroid carcinoma 6) primary thyroid lymphoma 7) metastatic cancer 8) risk factors a) family history of thyroid cancer b) history of radiation therapy to head & neck - other radiation exposure in childhood Epidemiology: - incidence has increased since 1980 due to an increase in diagnosis of small non-invasive cancers [2] Genetics: - implicated genes AMIGO2, SIRT7, DUSP26, FCGBP, SLC5A8, CD97, CDH1, BRAF Clinical manifestations: 1) enlargement of a goiter 2) nodular, firm 3) may become attached to adjacent structures 4) hoarseness may result from compression of the recurrent laryngeal nerve a) virutally pathognomonic of thyroid carcinoma b) vocal cord paralysis 5) enlarged regional lymph nodes [2] Laboratory: 1) fine needle aspiration cytology (FNAC) 2) serum TSH should be determined in all patients with thyroid nodules 3) serum calcitonin is recommended if: a) the FNAC results are inconclusive b) clinically the conclusion is suspicious or unclear c) preoperative diagnosis is unclear for other reasons 4) TSH-stimulated serum thyroglobulin 6 months after surgery & ablative 131I therapy 5) follow-up unstimulated serum thyroglobulin > 1 ng/mL (1.5 pmol/L) should initiate work-up of recurrence 6) anti-thyroglobulin antibodies in parallel with serum thyroglobulin 7) see ARUP consult [3] Special laboratory: - fine needle aspiration (FNA) a) thyroid nodules > 1 cm b) analyze aspirate for BRAF mutation when diagnosis is indeterminate Radiology: 1) ultrasound a) detect or exclude extrathyroidal disease b) identify ultrasonographic features of the index nodule c) 6 month follow-up ultrasound after surgery & ablative 131I therapy 2) scintigraphy a) not recommended for use in the primary diagnosis of thyroid carcinoma b) may reveal isolated areas of non-functioning thyroid tissue 3) whole body radioiodine uptake scanning Complications: - compression of the recurrent laryngeal nerve - men with a history of thyroid cancer have a higher cardiovascular risk compared with women [8] Management: 1) hemithyroidectomy is recommended for - unifocal papillary thyroid carcinoma < 1 cm if there is no indication of lymph node metastases [3] - unilateral differentiated thyroid cancers with 1-4 cm thyroid nodules if local or regional spread is not suspected - low-risk tumors are probably unnecessarily treated [5] - micropapillary lesions of indolent course need only observation [5] 2) total thyroidectomy followed by 131-I ablation if a) resection is not radical b) multifocal papillary carcinoma is found in the resected specimen from hemithyroidectomy, or c) there is an increased risk of malignancy in the contralateral thyroid lobe d) minimally invasive follicular thyroid carcinoma e) thyroid cancer not eligible for hemithyroidectomy 3) vocal cord assessment a) preoperative vocal cord assessment using laryngoscopy is indicated for patients with voice alterations or priorsurgery in the thyroid region b) postoperative vocal cord assessment, ~ one week after thyroid surgery, is indicated for patients with voice alterations or pronounced shortness of breath 4) levothyroxine suppression therapy following thyroidectomy or thyroid ablation a) serum TSH value < 0.1 mIU/L for 1st 2 years afer ablation b) after 2 years of TSH suppression (TSH <0.1 mIU/L), treatment may be adjusted to target a TSH value of 1 mIU/L 5) chemotherapy a) may be considered for patients with metastatic thyroid carcinoma who have failed all other therapeutic options & have indications of rapidly progressing disease b) does not prolong or improve quality of life for patients with metastatic thyroid carcinoma [2] c) sorafenib may extend progression-free survival in patients with metastatic thyroid carcinoma (10.8 months vs 5.8 months for placebo) [4] 6) treated well differentiated thyroid carcinoma has good long-term survival [2] 7) USPSTF recommends against screening for thyroid cancer [7] - even after thyroid irradiation (despite increased risk of cancer) [2]

Interactions

disease interactions

Specific

follicular thyroid carcinoma medullary thyroid carcinoma nonmedullary thyroid carcinoma oncocytic thyroid carcinoma; Hurthle cell carcinoma papillary thyroid carcinoma

General

carcinoma malignant endocrine neoplasm thyroid neoplasm (nodule)

References

  1. Williams Textbook of Endocrinology, 8th ed, JD Wilson & DW Foster (eds), WB Saunders Co, Philadelphia PA, 1992, pg 478
  2. Medical Knowledge Self Assessment Program (MKSAP) 14, 17, 18, 19. American College of Physicians, Philadelphia 2006, 2015, 2018, 2019. - Medical Knowledge Self Assessment Program (MKSAP) 19 Board Basics. An Enhancement to MKSAP19. American College of Physicians, Philadelphia 2022
  3. ARUP Consult: Thyroid Cancer The Physician's Guide to Laboratory Test Selection & Interpretation https://arupconsult.com/content/thyroid-cancer
  4. Physician's First Watch, June 3, 2013 David G. Fairchild, MD, MPH, Editor-in-Chief Massachusetts Medical Society http://www.jwatch.org - Brose MS et al Sorafenib in locally advanced or metastatic patients with radioactive iodine-refractory differentiated thyroid cancer: The phase III DECISION trial. 2013 ASCO Meeting Abstract J Clin Oncol 31, 2013 (suppl; abstr 4) http://meetinglibrary.asco.org/content/112795-132
  5. Brito JP et al Thyroid cancer: zealous imaging has increased detection and treatment of low risk tumours. BMJ 2013;347:f4706 PMID: 23982465 http://www.bmj.com/content/347/bmj.f4706
  6. Jonklaas J, Sarlis NJ, Litofsky D et al Outcomes of patients with differentiated thyroid carcinoma following initial therapy. Thyroid. 2006 Dec;16(12):1229-42. PMID: 17199433
  7. U.S. Preventive Services Task Force (USPSTF) Draft Recommendation Statement. Nov 2016 Thyroid Cancer: Screening https://www.uspreventiveservicestaskforce.org/Page/Document/draft-recommendation-statement169/thyroid-cancer-screening1 - US Preventive Services Task Force Screening for Thyroid Cancer. JAMA. 2017;317(18):1882-1887. PMID: 28492905 http://jamanetwork.com/journals/jama/fullarticle/2625325 - Lin JS, Aiello Bowles EJ, Williams SB, Morrison CC. Screening for Thyroid Cancer. Updated Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2017;317(18):1888-1903 PMID: 28492904 http://jamanetwork.com/journals/jama/fullarticle/2625324 - Cappola AR How to Look for Thyroid Cancer. JAMA. 2017;317(18):1840-1841 PMID: 28492886 http://jamanetwork.com/journals/jama/fullarticle/2625305
  8. Park J, Blackburn BE, Ganz PA et al Risk factors for cardiovascular disease among thyroid cancer survivors: Findings from the Utah cancer survivors study. J Clin Endocrinol Metab 2018. May 29 PMID: 29850817 https://academic.oup.com/jcem/advance-article-abstract/doi/10.1210/jc.2017-02629/5005948
  9. Haugen BR, Alexander EK, Bible KC et al 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. 2016 Jan;26(1):1-133. Review. PMID: 26462967 Free PMC Article
  10. Vaccarella S, Franceschi S, Bray F et al Worldwide Thyroid-Cancer Epidemic? The Increasing Impact of Overdiagnosis. N Engl J Med. 2016 Aug 18;375(7):614-7. PMID: 27532827