ANAPLASTIC THYROID CANCER Dr. TALAL MGBOULR(2)

DefinitionExtremely aggressive undiffrentiated tumor of thyroid follicular epithelium.

Epidemiology 1-2person per million person . Account 0.9 – 9.8 % of all thyroid cancer. Usually patient with anaplastic cancer

older than those with diffrentiated cancer. Mean age at diagnosis is 65 years and

less than 10% are younger than 50 years. 60-70% of cases occurs in women. 20% of patient have history of

diffrentiated thyroid cancer.

Transformation from diffrentiated to anaplastic cancer has been prescribed in patient who was followed with serial biopsies.

Up to have of patient have ahistory of multinodular goiter and some have history of partial thyroidectomy.

Study regarding ATC 1st study : Done in mayo clinic for 82 cases with ATC . Result: most common manifistation is rapid growth of

thyroid mass frequently in preexisting goiter. Favourable prognostic feature seem to be with

unilateral tumor diameter of tumor less than 5cm with no invasion of adjacent tissue and absence of nodal involvment.

For resectable lesions thyroid lobectomy with wide margin of adjacent soft tissue on the side to tumor seem to be safe.

Total thyroidectomy & radical neck dissection result in increase complication rate and have no advantage over more conservative approach.

2nd study was done in university of texas for 120 case of anaplastic cancer .

Result: Significant percetage of 35% of patient

had areas of well diffrentiated thyroid cancer.

Papillary thyroid carcinoma is the most common type associated with ATC.

This 2 study support the hypothesis that anaplastic tyroid carcinoma arises from preexisting well diffrentiated thyroid carcinoma.

Disease presentation :nearly all presented with thyroid mass.

Clinical manifistation: Rapidly inlarged mass 85%. Neck pain and tenderness from thyroid mass. Dyspnea in case of compression to

aerodigetive tract 35%. Dysphagia 30%. Hoarsness 25%. Chest pain &bone pain & headache&

confusion &abd pain (metastases).

Physical examination Most of patient with bilateral but

assymetric thyroid enlargment ,goiter is typically hard & nodular .

50% may have enlarged cervical lymph nodes.

Diagnosis FNA: Spindle cell & pleomorphic giant cell

tumor. Surgical biopsy: Used if FNA show necrotic or inflammed

tissue without specific diagnosis.

Metastases : Regional nodal metastasis & vocal cord

paralysis seen in upto 30-40%.Distant spread in present in about 75%of

cases at the time of diagnosis.Lung 80%Bone 6-15%Brain 5-15%

Staging : TNM CLASSIFICATION: All anaplastic carcinoma is stage IVStage IV contains 3 stages:IV A ; Tumor is limited to the thyroid and

surgically resected.IV B : Tumor extending beyond thyroid and

considered surgically unresected.IV C: Tumor presented with distant

metastasis.

TREATMENTMant therapeutical options:1) surgery.2) External radiotherapy3) Chemotherapy4) Mutlimodality therapy5) New therapies

Surgery: Most patients present at an advanced stage, making

curative surgical resection not feasible Some studies suggest that in a select subset of

patients with localized disease, survival can be improved by achieving complete resection of all gross disease.

Palliative management One of the central issues in the management of

ATC is palliation. Palliative management is meant to prevent death from asphyxiation.

Securing a safe airway is a critical component of this effort.

Airway management may be elective or emergent, depending on the patient’s presentation

Airway obstruction occurs by one of three mechanisms

1) external compression of the trachea (the

most common cause)

2)intraluminal tumor extension

3) bilateral vocal cord paralysis Patient with either stridor or rapid tumor

growth should considered for tracheostomy since further airway compromised is expected.

RADIOTHERAPYAchieving local control is important since death from

ATC is usually a consequence of uncontrolled local disease.

Although ATC is relatively radioresistant, some studies have shown palliative local control in 68% to 80% of patients.

Fractioned dose: 1,6 Gy/session, twice a day, triweekly, for a total dose of 57,6 Gy in 40 days.

CHEMOTHERAPY: Chemotherapy plays an important role in the

management of ATC since the majority of patients present with or develop distant metastases

NEW THERAPIES 1) Anti Tumor vascular targeting agent : One target,two way both inhibit tumor

blood supply. A) Antiangiogenic approach Prevent new vessel formation Acts slowly – weeks Promiscuous for all angiogenesis; impairs

wound-healing Tolerability issues

Vascular-disrupting approach Collapse and occlude pre-existing tumor

vessels Acts rapidly – hours Highly selective for abnormal vasculature Well tolerated

2)Tyrosine kinase inhibitors: s a pharmaceutical drug that inhibits 

tyrosine kinases. Tyrosine kinases are enzymesresponsible for the activation of many proteins by signaltransduction cascades. The proteins are activated by adding aphosphate group to the protein (phosphorylation). TKIs are typically used as anti-cancer drugs.

Sorafenib (tyrosine kinase inhibitor)

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