9: Differentiated thyroid cancer Flashcards
Rank the types of thyroid cancer from most common to least common.
Papillary (absolutely most common)
Follicular
Medullary (C cells)
Anaplastic (killer)
Papillary and follicular thyroid cancers are described as ___.
differentiated
Differentiated thyroid cancers secrete ___ and take up ___.
secrete thyroglobulin (used as a tumour marker)
take up iodine (so iodine can be used to both investigate and kill the cancer)
Which hormone drives papillary and follicular thyroid cancer?
TSH
Differentiated thyroid cancers have a (good / bad) prognosis.
good prognosis
Thyroid cancer is more common in (males / females).
females
Thyroid cancer is strongly associated with exposure to what?
Radiation
Thyroid cancer incidence increases following what type of accidents?
Nuclear incidents
e. g Chernobyl, Fukushima
www. theguardian.com/world/2014/mar/09/fukushima-children-debate-thyroid-cancer-japan-disaster-nuclear-radiation
How long does it take for thyroid cancer to develop following nuclear incidents?
4 years - several decades
What is found on thyroid examination in the majority of thyroid cancers?
Palpable nodules
Thyroid cancer is a chance finding following what procedure?
Thyroidectomy
for say hyperthyroidism secondary to Graves disease
What is the most common type of thyroid cancer?
Papillary
Papillary thyroid cancer spreads via which system?
Lymphatic system
Papillary thyroid cancer is associated with what type of thyroiditis?
Hashimoto’s thyroiditis
Follicular thyroid cancer tends to spread how?
Haematogenously
How are suspected thyroid cancers investigated?
Ultrasound-guided FNA
How is thyroid cancer initially treated?
Surgery
What are the surgical options for treating thyroid cancer?
Lobectomy (including the isthmus)
Sub-total thyroidectomy
Total thyroidectomy
Why isn’t lobectomy commonly carried out anymore?
Leaves half the thyroid intact, skewing thyroid function tests, drug doses etc.
Depending on the risk calculated following surgery, what treatment is added on for thyroid cancer?
Thyroid remnant ablation (TRA)
using radioiodine
Which risk stratification tool is used post-op in thyroid cancer?
AMES system
Age, Metastases, Extent of primary tumour, Size of primary tumour
The AMES system divides post-op thyroid cancer patients into which two groups?
Low risk (cancer is/was confined to the thyroid)
High risk (spread outwith the thyroid)
Which group of patients receive radioactive iodine treatment post-op?
High risk patients
In which type of cancer would lymph node surgery be considered in addition to surgery and TRA?
Papillary
because it tends to spread lymphatically
Why can patients become hypocalcaemic following thyroid surgery?
Removal of parathyroid glands
Following thyroid surgery, what drug are patients discharged with?
Thyroxine tablets
Calcium / recombinant PTH if parathyroids removed
What test is carried out 3-6 months post-op to detect remnants of thyroid cancer?
Whole body iodine scanning
to check for metabolically active cells, i.e cancer
What needs to be elevated before a patient recieves a whole body iodine scan?
TSH
to stimulate the metabolism of the cancer cells so they show up on the scan
How are a patient’s TSH levels raised prior to their whole body iodine scan?
Stop taking their thyroxine for 2-4 weeks (produces hypothyroid symptoms)
rhTSH injections (don’t need to stop thyroxine, but very expensive)
If thyroid cancer is still active following surgery, what treatment is given to patients?
Thyroid remnant ablation
using radioactive iodine
Patients undergoing thyroid remnant ablation need to have a (raised / suppressed) TSH and undergo treatment (at home / in isolation).
raised TSH
in isolation (as their necks are really radioactive)
What protein is used as a tumour marker for differentiated thyroid cancer?
Thyroglobulin
as it is produced by papillary and follicular carcinomas
thyroxine precursor
Following treatment for differentiated thyroid cancer, you want to keep a patient’s TSH (high / low).
low
remember that it drives the cancer
so high to investigate, low post-op
What is an uncommon disease which can be caused by thyroid remnant ablation?
Acute myeloid leukaemia (AML)
patients must be informed of this (1 : 10000 chance)
How often are thyroid cancer patients followed up in clinic post-treatment?
Every 2 months
Following treatment for thyroid cancer, what are patients put on?
Thyroxine tablets
How can you tell if thyroid cancer has recurred?
Raised thyroglobulin
Metastasis to other parts of the body
If a patient has suspected recurrence of thyroid cancer, what test would you do?
Whole body iodine scan
again
What is the recurrence rate of differentiated thyroid cancer?
30%
Apart from whole body iodine scanning, what other imaging may be used to identify areas of active cancer i.e in metastatic disease?
PET scan
What is the general timeline of investigation and treatment in a patient presenting with DTC?
Ultrasound-guided FNA
Surgery
Whole body iodine scan –> Thyroid remnant ablation
Thyroxine and regular follow-up
