Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Thyroid Cancer
Document related concepts
no text concepts found
Transcript
Thyroid Cancer Steven W. Harris MHS, PA-C Epidemiology Annual Incidence of 23,600 3:1 female to male ratio Increases with age 2% of clinically detected malignancies 14th Most common malignancy in the US Falls behind: Lung Breast Prostate Colon Pancreas Bladder 2003 Estimated US Cancer Cases* Men 675,300 Women 658,800 32% Breast Prostate 33% Lung & bronchus 14% Colon & rectum 11% Urinary bladder 6% 6% Melanoma of skin 4% Non-Hodgkin lymphoma Kidney 3% Oral Cavity 3% Leukemia 3% Pancreas 2% All Other Sites 17% 12% Lung & bronchus 11% Colon 4% & rectum Uterine corpus 4% Ovary 4%Non-Hodgkin lymphoma 3% Melanoma of skin 3% Thyroid 2% Pancreas 2% Urinary bladder 20% All Other Sites *Excludes basal and squamous cell skin cancers and in situ carcinomas except urinary bladder. Source: American Cancer Society, 2003. So WHY are we discussing this today? Additional epidemiology Incidence of thyroid cancer is growing faster than any other malignancy Treatment is highly effective 3.8 % annual increases from 1992 to 2001 > 95 % of all patients survive > 300,000 thyroid cancer survivors in the US All require monitoring for recurrent disease PLUS… So WHY are we discussing this today? Thyroid Gland Anatomy Largest endocrine gland, very vascular Anterior and lateral sides of trachea 2 large lobes connected by isthmus Thyroid Physiology thyroid hormone secretion controlled by TSH hormones: Thyroxine (3,5,3’,5- Tetraiodothyronine) T4 greatest amount of thyroid hormone Triiodothyronine ( 3,5,3’, L-triidothyronine) T3 most biologically active liver also converts T4 into T3 (80% of T3 via liver) Reverse-Triiodothyronine active thyroid hormone RT3 minor biologically Thyroid Anatomy & Physiology thyroid hormone production strictly dependent on Iodine 90% of body stores of Iodine found in thyroid gland most of which is bound to thyroglobulin from dietary sources ~700ug day thyroglobulin in thyroid gland traps iodide and oxidizes into iodine Thyroid Hormone Effects General Characteristics Papillary carcinoma 76% Follicular carcinoma 16% Medullary carcinoma 4% Lymphoma/metastatic 3% Anaplastic carcinoma 1% Distinguishing Characteristics. Papillary carcinoma Follicular carcinoma Hematogenous metastasis Medullary carcinoma Lymphatic Metastasis Least aggressive Associated with increased dietary iodine flushing, pruritus, and diarrhea Associated with MEN-II Anaplastic carcinoma Generally pts over 60 Most Aggressive Etiology and Pathogenesis Genetic Predisposition Familial syndrome Familial adenomatous polyposis (APC gene mutation) Cowden syndrome: hamartoma (PTEN gene mutation) Familial isolated papillary thyroid cancer Familial Multiple Endocrine Neoplasia MEN-II 10 % of all thyroid cancers Etiology and Pathogenesis Thyroid irradiation Accidental radioiodine exposure Radiotherapy: tonsillitis, lymphoma Radioactive iodine fallout (I-131) Common prior to 1950s http://www.cancer.gov/cancer_information/doc.aspx?vie wid=4ea8b4a2-b6d8-44b3-8e2f-7ce624a130d2 Unknown Controversial Evidence Preexisting benign thyroid conditions Parity Estrogen therapy Therapeutic radioiodine exposure Dietary Factors Iodine intake more papillary cancers in populations with generous dietary iodine content. Presentation Common Painless neck swelling Palpable solitary nodule Fixed Stony/hard Euthyroid Incidental finding Ipsilateral cervical lymphadenopathy Less common Pain Hoarseness anaplastic Hemoptysis Dysphagia A nodule or a NODULE? Nodules found in 6% of females and 2% of males 5% - 10% are malignant Increased suspicion Enlargement over weeks to months Decreased suspicion Stable size Sudden appearance: hemorrhage Workup of a nodule TFT Ultrasound solid or cystic Thyroid scan usually normal hot or cold FNAB histology Thyroid Ultrasonography dimensions of thyroid lobes or nodules down to 1 mm <1 cm no clinical significance solid, cystic, or mixed suggests if papillary adenocarcinoma used for monitoring nodules growth (i.e. not “normal tissue”) during TSH suppression, may prompt repeat biopsy or surgery Thyroid Imaging: Radionuclide Scanning technetium (99mTc) or isotope of iodine (131I) 99mTc can be concentrated, but not bound to TBG and thus not stored in colloid, so some cold nodules can appear warm 131I –both concentrated & organified to TBG; scan 24 hours after oral 131I qualitative-size quantitative-uptake used to determine if nodule “Hot” or “Cold” almost all cancers are cold however most benign lesions cold also replaced by fine needle biopsy as TOC for nodule work-up FNAB Cold Nodule Treatment: Papillary/Follicular Total or near-total thyroidectomy selective lymph nodes vs. radical neck dissection Adjunctive Radioactive Iodine ablation Residual disease TSH stimulation thyroid hormone withdrawal Recombinant TSH Increased TSH, increases residual thyroid tissue uptake of Iodine Treatment cont. TSH suppressing thyroid hormone therapy Euthyroid Suppression of tumor recurrence Long-term follow-up to detect recurrent disease Circulating serum thyroglobulin Thyroid ultrasound CT of chest Whole body scan Repeat surgery Treatment: Medullary Thyroidectomy Thyroid replacement therapy Not TSH suppression Monitor with serial serum markers Calcitonin CEA Repeat surgery External beam radiotherapy Treatment Lymphoma Lymphoma combined chemotherapy and radiation therapy Anaplastic typically nonresectable treated with combined external-beam radiotherapy and chemo therapy. Only in exceptional cases, however, do these interventions significantly alter the grim prognosis. Complications Natural Course Hoarseness Dysphagia Dyspnea Esophageal strangulation Malnutrition Pulmonary failure Paresis Bony fractures Neurological cons. Thyrotoxicosis Treatment Hoarseness Hypoparathyroidism Radioiodine Gastritis Sialoadenitis Dental caries Dry mouth leukemia Prognosis: post therapy High survival rates 98% Papillary 92% Follicular 80% Medullary 33% of papillary tumors recur Extracervical medullary CA is incurable Slow progression Anaplastic cancers unfortunately can be among the most aggressive and treatment-resistant malignancies known Monitoring Evaluate thyroglobulin serum levels every 6-12 months for at least 5 years Repeat the nuclear scan 6-12 months after ablation and, thereafter, every 2 years. Before the scan, levothyroxine must be withdrawn for approximately 4-6 weeks to maximize thyrotropin (TSH) stimulation of the eventual remaining thyroid tissue OR rTSH two days before scan Check those thyroids!
