Thyroid Cancer1 Flashcards
What is the lifetime risk for developing thyroid cancer in women and men?
The lifetime risk of developing thyroid cancer in the United States is estimated to be 0.8% for women and 0.3% in men.ﾠ
How is thyroid cancer categorized?
It is categorized into follicular cell-derived and non-follicular cell derived variants.
Follicular cell derived malignancies include papillary thyroid cancer, follicular cancer, Hurthle cell cancer, andﾠanaplastic cancer.
Non-follicular cell derived malignancies include medullary thyroid cancer, lymphoma, and metastases.
What inherited syndromes are associated with thyroid cancer?
Multiple endocrine neoplasia (MEN) 2A and 2B
Isolated familial medullary thyroid cancer
Gardner syndrome
Familial adenomatous polyposis
Carney complex
Cowden syndrome
Familial nonmedullary thyroid cancer
In which patients, a fine needle aspiration is indicated?
Patient with nodules of 1 cm or larger and nodules smaller than 1 cm with suspicious sonographic features.
If a FNA identifies medullary thyroid carcinoma, what should be next step in management?
Obtain a baseline serum calcitonin level and screened the paitent for pheochromocytoma and hyperparathyroidism.
What is the overall 10-year survival rate for papillary thyroid cancer?
93%
What is the most common thyroid cancer associated with previous history of radiation?
Papillary thyroid cancer
In papillary thyroid canrcinoma, how common is to find cervical lymph node involvement?
Common and occurs in up to 50% of patients.
Why a total thyroidectomy can be considered an optimal therapy in patients with low-risk papillary thyroid carcinoma?
- Total thyroidectomy is associated with the lowest incidence of local and regional recurrence.
- It also allows for the most effective use of serum thyroglobulinﾠand radioiodine for detection of recurrent disease and high-dose radioiodine for treatment of metastatic disease.
- Total thyroidectomy also eliminates a 1% incidence of anaplastic dedifferentiation.
Mention the criteria for distinguishing a low-risk well-differentiated thyroid carcinoma.
Women < 4cm in diameter
Tumor confined to thyroid
No distant metastases
Mention the criteria for distinguishing a high-risk thyroid carcinoma?
Women >50 years Men >40 years Poorly differentiated tumor Tumor > 4cm in diameter Local invasion Distant metastases
A central neck dissection consists of?
Consists of removal of all lymph nodes and fibrous fatty tissue from the hyoid bone superiorly to the brachiocephalic artery inferiorly and between the common carotid arteries laterally. The prelaryngeal, pretracheal, and paratracheal lymph nodes, which comprise the level VI nodes, are removed.ﾠ
How the recommendations for central neck dissection from the American Thyroid Association (ATA) varies from the National Comprehensive Cancer Network (NCCN)?
The ATA recommends that a routine central neck dissection be considered for patients with papillary thyroid carcinoma, whereas the NCCN only recommends central neck dissection for grossly positive lymph node metastases. The rationale for prophylactic central neck dissection is that the likelihood of occult microscopic disease is high, and reoperation for a recurrence in the central neck may be associated with a high complication rate.ﾠ
What percentage of follocular thyroid patient have lymph node metastases?
less than 10%
What is the overall 10-year survival rate for follicular thyroid cancer?
85%
Of all the well differentiated thyroid cancers, which has the highest incidence of metastases?
Hurthle cell carcinoma
T/F: Hurthle cell carcinoma is radioresistant and has a worse prognosis than papillary or follicular thyroid carcinoma, with a 10 year survival rate of approximately 75%.
TRUE
Which patients should undergo radioiodine ablation and why is helpful?
Should be recommended for patients with incomplete tumor resection, extrathyroidal tumor spread, nodal or distant metastases, or aggressive histology (tall cell, columnar cell, or diffuse sclerosing carcinoma).
It helps to optimize the use of serum thyroglobulin and radioiodine whole-body scanning for detection of recurrent disease.
What is the preparation needed for the patient prior ablation therapy?
Patients are placed on short-acting triiodothyronine (T3) postoperatively, 25 ﾵg twice a day, to minimize the period of hypothyroidism. Two weeks before receiving iodine, T3 is discontinued, and the patient is placed on a low-iodine diet to maximize the uptake and retention of radioiodine by the remnant tumor cells. Prior to proceeding with radioiodine ablation, the patientﾒs serum TSH level should be greater than 30 ﾵIU/mL to enhance radioiodine uptake by the residual normal follicular cells and tumor cells.
What are the recommendations for the TSH level postoperatively in patients following radioiodine therapy?
Following radioiodine ablation, patients are started on levothyroxine 2 ﾵg/kg per day, and serum TSH is measured 5 to 6 weeks later. The goal is to maintain the serum TSH level between 0.1 to 0.5 ﾵIU/mL, for patients with high-risk differentiated thyroid cancer (DTC) who are free of disease, and between 0.3 to 2.0 ﾵIU/mL for patients with low-risk DTC. In patients with metastatic disease, maintain a serum TSH level less than 0.1 ﾵIU/mL.
