451 Thyroid cancer.ppt classification and treatment

Classification
Treatment
Staging

1. Thyroid
Cancer
Dr.AwadAlqahtani
Md,MSc.FRCSC(G.Surgery)FRCSC(Surgical Oncology)
Laparoscopic and Bariatric Surgery

2. Outlines
•Anatomy and Blood Supply
•Epidemiology
•Causes and Risk Factors
•Classification
•Clinical Presentation
•Diagnosis
•Management

6. Epidemiology
•Commonest endocrine malignancy
o1% of all malignancies
o0.5-1 per 100000
•Good prognosis
•Extent of treatment is hotly debated
oNo randomized trials
•Annual Incidence is 3.7 per 100,000
•Sex Ratio is 3:1 (Female:Male)
•Can occur at any age group

7. Causes and Risk Factors
•Genetics:
oAbnormal REToncogene may cause MTC.
oMEN 2A, 2B Syndrome.
•Family History:
oHx of goiters increase risk for Papillary Ca.
oGardner’s Syndrome and FAP increase risk for Papillary Ca.
•Radiation Exposure:
oRadiation therapy to Head or Neck.
oExposure to Radioactive Iodine during childhood, or other radioactive substances
(Chernobyl) ↑ risk for particularly Papillary carcinoma.

8. Causes and Risk Factors
•Chronic Iodine deficiency ↑ risk for Follicular carcinoma.
•Gender:
oFemale > Males.
•Age:
oMore common at young adults.
oMTC usually diagnosed after 60.
•Race:
oWhite race > Black race.

9. Thyroid Neoplasm
Benign Malignant
SecondaryPrimary
Follicular
Cells
Parafollicular
Cells
Lymphoid
Cells
LymphomaMedullary
Differentiated Undifferentiated
Anaplastic
Follicular
Papillary
Hurthle Cell

10. Presentation
•Solitary or Multiple thyroid nodules
•Neck Nodes
•Hoarse voice of recent onset
•Mediastinal adenopathy
•Bone or lung metastasis

11. Important History
•Radiation to neck / chest
•MEN syndrome
oFamily history
oDiarrhoea
oAdrenal tumour
•Recent change in a pre-existing goitre
oSize change/nodularity
oVocal cord palsy

12. Evaluation
•Thyroid profile
•Serum Thyroglobulin
•Serum Calcitonin
•Thyroid scan
oHot/warm/cold nodule 20% malignant
•Serum Ca
++

13. Diagnosis
•Laboratory:
oTSH
oT3, T4
oSerum Thyroglobulin
oSerum Thyroid Antibodies
oFNA
•Imaging
oU/S
oC.T
oMRI
oScintigraphy

14. Laboratory
•Most patients are Euthyroid.
•Hyperfunctioning nodule 1% chance of malignancy.
•Serum Tg cannot differentiate between benign and Malignant
nodules
•Tg is used for:
oF/U after total thyroidectomy
oSerial F/U for non-operative treatment
•Serum Calcitonin patients with MTC, or with family hx of
MTC (MEN2)

15. FNA Cytology
•Single most important test.
•U/S guidance improve the sensitivity.
•Accuracy ranges from 70 –95%.
•Nodules
•FNAC cannot differentiate between Benign and Malignant
Follicular Neoplasia

17. Imaging
•U/S is the investigation of choice.
•C.T Regional and distant metastases
•MRI Limited role in the diagnosis
Useful in detecting cervical LN metastases
•Scintigraphy (I-123)
•Characterizing funtioning nodules
•Staging of follicular and papillary Ca

18. Prognostic Indicators
•AGESscore:
•Age
•Hisological Grade
•Extrathyroidal invasion
•Metastasis
•MACISscore (post-operative):
•Distant Metastasis
•Age
•Completeness of original surgical resection
•Extrathyroidal Invasion
•Size of original lesion

21. Management
•Medical
oRadioactive Iodine ablation therapy.
oChemotherapy (Adriamycin, Cisplatin).
oPost-operative Thyroid hormone.
•Replacement therapy.
•Suppression of TSH release. (↓ recurrence)
•Surgical
•Treatment of choice.
•Extent of resection is still controversial.

22. Thyroid Surgeries
•Relates to the management of contralateral lobe.
•Types
Ipsilateral lobectomy
Subtotal Thyroidectomy
Near-total Thyroidectomy
Total Thyroidectomy

23. Papillary Carcinoma
Most common Thyroid carcinoma (80%)
Related to radiation exposure in I-sufficient areas.
Female:male ratio is 2:1
Mean age of presentation is 30 to 40 yrs.
Slow growing painless mass. Euthyroid-status.
LN metastases is common, may be the presenting
symptom (Lateral Aberrant Thyroid).
Distant metastases is uncommon at initial presentation.
Develop in 20% of cases. (Lungs, liver, bones,brain)

24. Papillary Carcinoma
•FNA biopsy is diagnostic.
•Treatment
•Ipsilateral Lobectomy + Isthmusectomy (No LN metastasis)
•Near-total or Total Thyroidectomy + Modified-radical or
Functional neck dissection (+ve LN metastasis).
•Prophylactic LN dissection is unnecessary.

25. Follicular Carcinoma
•Account for 10% of all thyroid cancers.
•More common in I-deficient areas.
•Female:male ratio is 3:1
•Mean age at presentation is 50 yrs.
•Solitary thyroid nodule, rapid increase in size and long-
standing goiter.
•Cervical LN metastasis is uncommon at presentation (5%),
distant metastasis may be present.
•Hyperfunctioning < 1%. (S&S of Thyrotoxicosis)

26. Follicular Carcinoma
•FNA biopsy cannot differentiate between benign and
malignant follicular tumors.
•Pre-operative diagnosis of malignancy is difficult unless there is
distant metastasis.
•Large follicular tumor > 4 cm in old individual CA.
•Treatment:
•Thyroid Lobectomy (at least 80% are benign adenomas)
•Total-Thyroidectomy in older individual with tumor > 4cm (50%
chance of malignancy).
•Prophylactic nodal dissection is unnecessary.

28. Post-operative
Management
•Thyroid hormone
oReplacement therapy
oSuppression of TSH release
•At 0.1 μU/L in Low-risk group
•< 0.1 μU/L in High-risk group
•Thyroglobulin measurement
oAt 6-months interval then annually when disease-free
o< 2ng/mL in total or near-total + Hormones
o< 5ng/mL in hypothyroid patients.
oLevel > 2ng/mL = Recurrence/Persistent thyroid tissue

29. Post-operative
Management
•Radioiodine Therapy:
oControversial (No prospective RCTs).
oLong-term cohort studies by Mazzaferri and Jhiang and DeGroot:
•Small improvement in survival rate and less recurrence when RAI
is used, even with Low-risk group.
oRAI is less sensitive than Tg in detecting metastatic disease.
oI-131 detect and treat 75% of metastatic differentiated thyroid tumors.

30. Medullary Carcinoma
•5% of all thyroid malignancies.
•Arise from Parafollicular cells, concentrated in superolateral
aspect of thyroid lobes.
•Most cases are sporadic, 25% are inherited (Germline mutation
in REToncogene).
•Female:Male ratio is 1.5:1
•Most patients present between 50 and 60 yrs.
•Neck mass + palpable cervical LN (15-20%).
•Local pain or aching is common.

31. Medullary Carcinoma
•MTC secrets a range of compounds:
oCalcitonin, CEA, CGRP, PG A2and F2α, Seritonin.
oMay develop flushing and diarrhoea, Cushing’s syndome (ectopic ACTH).
•Diagnosis
oHx and P/E (Family hx of similar tumors).
o↑ Serum Calcitonin, ↑ CEA
oFNAC
•Screen patient for:
oRETpoint mutation.
oCoexisting Pheochromocytoma (24-hour urinary level of VMA, catecholamine,
metanephrine).
oHyperparathyroidism (Serum calcium).

33. Medullary Carcinoma
•Treatment:
o> 50% are bilateral, ↑ Multicentricity.
oTotal Thyroidectomy + :
•Bilateral central node dissection as routine (No LN involvement)
•Bilateral Modified-Radical Neck dissection (palpable LN)
•Ipsilateral Prophylactic nodal dissection in tumor size > 1.5cm.
oExternal Beam radiation for unresectable residual or recurrent tumor.
oNo effective Chemotherapy.

34. Medullary Carcinoma
•Prophylactic Thyroidectomy in RETmutation detection
oBefore age of 6 yrs for MEN2A
oBefore age of 1 yr for MEN2B

35. Anaplastic Carcinoma
•1% of all thyroid malignancies.
•Women > Men.
•Majority present at 7
th
-8
th
decade of life.
•Long-standing neck mass, rapidly enlarging in size.
•May be painful, with dyphonia, dyspnea, dysphagia.
•LN are usually involved at presentation.
•±Distant metastasis.

36. Anaplastic Carcinoma
•FNAC is diagnostic.
•Treatment:
oMost aggressive thyroid tumor.
oTotal Thyroidectomy if resectable.
oAdjuvant Chemotherapy + Radiotherapy slightly improve long-term survival.

37. Other Types
•Thyroid Lymphoma:
o1% of all Thyroid Ca.
oMost are Non-Hodgkin B-cell
Lymphoma.
oUnderlying chronic lymphocytic
thyroiditis.
oFNAC is diagnostic.
oCombined Chemotherapy (CHOP) +
Radiotherapy.
•Hurthle-Cell Carcinoma:
o3% of all Thyroid Ca.
oSubtype of Follicular Ca.
oMore multicenteric and bilateral (30%).
oFNAC is not conclusive.
oLobectomy + isthmusectomy (unilateral)
oTotal Thyroidectomy (bilateral)

38. Prognosis
Tumor Prognosis
PapillaryCa.
74-93%long-term survival
rate
Follicular Ca.
43-94% long-term survival
rate
HurthleCell Ca.
20% mortality rate at 10
years
MedullaryCa.
80% 10-year survival rate
45%with LN involvement
AnaplasticTumor
Median survival of 4 to 5
months at time of diagnosis