Week 3 - F - Week 3 -Differentiated thyroid cancer Flashcards
What are the 4 types of thyroid cancer? (that we need to know) Which are differentiated and which are undifferentiated?
Papillary carcinoma - differentiated
Follicular carcinoma - differentiated
Medullary carcinoma - differentiated
Anaplastic carcinoma - undifferntiated
Does a differentiated or undifferentiated thyroid cancer have a better prognosis?
Differentiated thyroid cancer has a better prognosis
Exposure to what increases the risk of a thyroid cancer? What gender is thyroid cancers more common in?
Iodine radiation exposure
More common in females
Does smoking have any association to thyroid cancer?
No known association
What autoimmune condition is papillary thyroid cancer associated with? How does it tend to spread? Tends to have a good prgnosis
Associated with Hashimoto’s thyroditis
Spreads via lymphatics or haematogenous spread
95% survival at 10 years
What is the second most common thyroid cancer? How does it spread and what people does it more commonly affect?
Follicular thyroid cancer
Spreads via haemategenous route
Slightly more common in areas with an iodine deficiency
How is a biopsy of the thyroid usually taken? Are CT or MRI used?
Usually ultrasound-guided fine needle aspiration
No role for CT or MRI
Due to the fact fine needle aspiration only examines cells and not the capsule, what type of thyroid carcinoma can FNA not be used in?
follicular carcinoma
– hence distinction between follicular adenoma and carcinoma cannot be made by FNA as it is invasion through the capsule that helps distinguish the follicular carcinoma from the follicular adenoma
What is the substance that medullary thyroid cancers deposit in the tumour as amyloid?
Calcitonin
Due to the high levels of calcitonin prduced by the medullary thyroid cancer, what may this do to calcium levels?
May cause hypocalcaemia
What does parathyroid hormone do to calcium levels in the blood and how?
PTH increases the osteoclastic activity of bone causing calcium to be released into the blood therefore increasing calcaemia
What age is an indicator of thyroid cancer?
Red flag age is similar to red flag for back pain
A new thyroid nodule at the age of less than 20 or greater than 50
Other risk factors of thyroid cancer include: History of head and neck irradiation Vocal cord palsy
What size of nodule is a risk factor of thyroid cancer?
lesion > 4cm in diameter
What is the treatment of choice in a thyroid cancer?
Surgery
What is the classifaction system for low and high risk patients used by ninewells for people with tyroid cancer?
Age
Malignancy
Extent of primary tumour
Size of primary tumour
If there is no capsular invasion in the patient, is this high risk or low risk?
This is a low risk patient
In people with thyroid cancer All patients with distant metastases are high or low risk?
All patients with distant metastases are high risk
Why are sub-total thyroidectomys carried out instead of total thyroidectomy?
Subtotal thyroidectomy is a surgical procedure, in which the surgeon leaves a small thyroid remnant in situ to preserve thyroid function, thereby preventing lifelong thyroid hormone supplementation therapy.
When continuing post-operative care, what mineral level must be checked within 24 hours and why?
Check calcium levels as this can drop due to parathyroid glands also being removed
How should calcium be administered if calcium levels fall below 1.8mmol/L? (normal range - 2.2 to 2.7 mmol/L)
Give intravenous calcium
Why are whole body iodine scans carried out?
If the patient is suspected of metastases carry this out to see if there are any tumours elsewhere
Why do TSH levels need to be high for a whole body iodine scan ? (preferably above 20)
Aim is to make cancer cells hungry for iodine this is done by increasing TSH levels which is increased by giving rhTSH (recombinant human TSH)
TSH causes T3 and T4 production by uptaking iodine and therefore any metastases will show clearly if TSH level is high
Surgery is gold standard for thyroid cancer What is carried out following surgery?
Thyroid radiation ablation (with radioiodine) - Pre-treated with rhTSH as before
What percentage of the thyroid radiation ablation (TRA) is excreted in the first 24 hours?
80%
To ensure the uptake of iodine in the thyroid bed is now less than 0.1%, showing malignancy has been removed, what procedure is re-performed?
Re-perform the whole body iodine scan
What is produced by thyroid cells and thyroid cancer cells that can be used as a tumour marker? – nothing else produces this, therefore after total thyroidectomy, if there level isn’t 0 as no thyroid cells exist, then there is cancer cells somewhere
Thyroglobulin
If the patient has the gold standard, surgery, TRA and follow up, what disease can this increase the risk of by double?
Doubles risk of leukaemia
(Acute myeloid leukemia (AML) is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal white blood cells that accumulate in the bone marrow and interfere with the production of normal blood cells.)
What is the recurrence rate of thyroid cancer after the treatment?
30%
(Difficult group are those with rising Tg but negative whole body I-131 scan )
