Download thyroid cancer

Thyroid Malignancies
In Children
Bhaskar N. Rao, M.D.
St. Jude Children’s Research
Hospital
10/03
THYROID CANCER
Staging
T0
T1
T2
T3
T4
No evidence of tumor
tumor <1 cm
tumor 1-4 cm
tumor >4 cm
tumor any size beyond capsule
N0
N1
N1a
N1b
No nodal mets
regional nodes
ipsilateral cervical nodes
bilateral or mediastinal
M0 N0 distant mets M1 distant mets
THYROID CANCER
Staging (Pap/follicular)
Age <45
Stage 1
Any T
Any N
M0
Age >45
Stage 1
T1
N0
M0
Stage 2
T2/T3
N0
M0
Stage 3
T4 or
T1-4
N0
N1
M0
M0
Stage 4
T1-4
Any N
M1
Anaplastic
All cases are stage IV
Staging (Medullary)
Stage
1
T1
N0
M0
2
T2-4
N0
M0
3
Any T
N1
M0
4
Any T
Any N
M1
Thyroid Cancer
Epidemiology
• 20,000 new cases/year in the US
– more often in women and whites
• Peak incidence: 40 (women), 60 (men)
• Lifetime risk: 1%
• Histology: Papillary - 80%
Follicular - 11%
Hurthle cell - 3%
Medullary - 4%
Anaplastic - 2%
Thyroid Cancer
Epidemiology - Children
• Low incidence in childhood
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1.5% of all tumors < 15 years
peak 7-12 years
10% of all head and neck cancer
10% are diagnosed in childhood
2/3 in girls
• Indolent course, even with metastases
– Survival > 90%
• Up to 8% of secondary pediatric cancers
Thyroid Cancer
Epidemiology - Children
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Low dose RT used for Thymus, Hemang, Acne
Average dose 600cgy. One million people at risk
One fourth will develop nodules
Most (75%) Benign Hyperplasia, Adenoma, Fibrosis
Treatment Lobectomy – Post-op Hormones
Thyroid Cancer
Epidemiology - Children
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Increased risk of Carcinoma
Most are Papillary Carcinomas (20-50%)
Latency median 20 years
Most are multicentric, with lymph nodes
Other tumors – Salivary Gland, Parathyroid, Bone,
Soft tissue Sarcomas, Thyroid lymphomas
Thyroid Cancer Histology
• Papillary
– 80% incidence increases with younger age
– High incidence of bilaterality, regional nodes
• Follicular
– Rare in children
– Distinguished from adenoma by vascular or capsular invasion
• Medullary
– arise from calcitonin-secreting c-cells
• Anaplastic
– Extremely aggressive, high mortality
Tumor Variable Affecting Prognosis
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Histology
Size
Local invasion
Lymph node
Distant metastases
Thyroid Cancer
Epidemiology - Children
• Thyroid cancer has proven to be a common SNM
• Between 1980 & 1987 58 centers in Europe reported
239 SMN’s
• 18 of 239 (7.5%) were thyroid cancers
• 6 / 18 primary was Hodgkins all received chemo +
RT (25-42gy)
• 7 / 18 primary was ALL all had CS RT (18-24gy)
• 2 Ewings, 1 Wilms, 1 NB and 1 NPC
Thyroid nodules
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By far most thyroid nodules are benign
and are either colloid nodules,
adenomas or manifestations of
thyroiditis
They may be cystic or solid
Most cystic are generally benign
(degenerated colloid)
They may be toxic or non toxic
Thyroid Cancer
Pediatric vs. Adult
• Thyroid masses more likely to be cancer
– 50% of solitary nodules are malignant
– More often larger, multicentric
• Higher rate of metastasis at diagnosis
– regional lymph nodes: 65% (35% adult [papillary])
– distant: 20% (10% adult [follicular])
• Higher rate of recurrence
– 40% <20y (also >60y); 20% adults
– 80% locoregional, 20% distant (similar)
Thyroid Cancer
Diagnostic Imaging
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Traditionally I131 Now I123 or Technitium scans
Nodules hyperfunctional (hot) with increased avidity
Functional cold same as rest of gland
Minimum 1 cm diameter for cold nodules
Hot functional nodules practically benign
Cold – incidence of malignancy higher
Thyroid Cancer
Diagnostic Imaging
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USG – differentiate multinodular vs solitary
CT or MRI – invasive lesion or sub-sternal location
Specific / sensitive is F.N.A.
Malignant, suspicious, benign or inadequate
If it is suspicious I123 , hot, rarely malignant
cold 20% or higher
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Thyroid Cancer
Pediatric vs. Adult
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Better overall survival
– >95% for children
– 75-90% for adults
Better survival with metastases
– 86% of children
– 32% of adults
Thyroid malignancies in pediatric population – how is it different?
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Papillary ca. constitutes 85-90% of all malignant lesions with medullary
second, forming 5%
Unlike adults follicular not as common and when present it is usually in the
adolescent population
Thyroid lymphomas and metastasis are hardly ever seen in pediatric
population
In familial medullary ca. prophylactic thyroidectomy is done in kids before
they attain age 5yr
PARADOX:
– often presents with extensive disease and progression or
recurrence in a significant number of patients
– is rarely fatal
Suggests biologic rather than treatment factors have a greater
effect on outcome
Approach to a malignant thyroid nodule
Clinically suspicious nodule >1cm
• Increased suspicion • Highly suspicious
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Male
Nodule > 4cm
Age < 15 yr
H/O XRT exposure
H/O
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Pheochromocytoma
Hyperparathyroidism
Gardner’s
FAP
Carney’s complex
Cowden’s syndrome
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Rapid nodule growth
Fixation
Family history
V.C paralysis
Lymph nodes
Neck invasion
TSH
FNA of nodule/ lymph nodes
If insufficient FNA → repeat FNA (imparts 50% extra chance)
US
solid or cystic and assist in FNA and determining the size of the
nodule
Cystic nodules may be followed
Thyroid Carcinoma
• Fine needle aspiration important
• Distinguishing benign/malignant follicular difficult
• Thyroid nodules containing follicular cytopathologic
features have 20-30% malignancy
• Thyroid malignancy rate is 6.8% without atypia and
44-50% with atypia
•Allows for conservative approach in selected patients
Thyroid Cancer
Surgical Options
• Total Thyroidectomy in patients with invasive or
metastatic or bilateral or previous RT
• For others – controversy varies with surgery and
complication rates
• Unilateral P.C. or F.C. < 1.5 cm lobectomy + isthmus
• If > 1.5 cm opposite lobe 30-80% recurrence rate is
10%
• Recurrence associated with 30% mortality with 50%
desease found in central neck
• Total Thyroidectomy recurrence less than 5%
sup. parathyroid
recurrent laryngeal n.
Thyroid Cancer
Surgery Risk vs. Benefit
• Total Thyroidectomy
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High risk groups: radiation, MTC, Anaplastic
Simplifies use of radioiodine
Follow thyroglobulin levels
Increased risk without increased survival benefit
• 15% each-recurrent laryngeal nerve injury, hypoparathyroidism
• 30% higher than lobectomy
Thyroid Cancer in Childhood
sup. parathyroid
Challenges of Thyroid
Cancer Management
recurrent laryngeal n.
• No prospective randomized trials of treatment
• The prognosis is generally excellent
Thyroid Carcinoma
Minimally Invasive Surgery
Criteria by Niccoli et al. (Am J Surg, 2001)
• Nodules less than 3.5 cm
• Total thyroid volume less than 15ml
• No previous neck surgery or irradiation
• Absence of thyroiditis/invasion
• Total 336 pts. One-third total thyroidectomy
• Conversion 4.5%
Yamashita et al.
•25-30 mm transverse upper lateral neck
• Total 39 pts.
Recurrent nerve injury one
• Tumor size
1.9 – 5.5 cm
• Surgery
56 mm (36-90 minutes)
• Other approaches described
Axillary Approach
Approach to a thyroid nodule
(Papillary on FNA-high risk)
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Papillary ca. (dx. By FNA) and high
risk
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Total thyroidectomy
If L.N positive
– Central neck disec
– Lateral neck disec.(level II-IV,
sparing spinal accessory nerve,
int. jugular, SCM)
Management post lobectomy for
papillary (<1cm- low risk)
• Their recurrence and cancer specific
mortality rates are almost zero
• Supress TSH with thyroxine
• Tg and whole body I scan are insensitive
• Physical exam with local neck US seem to
be the best suggested follow up
Follow up papillary
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P/E q 3-6 mo for 2yrs with periodic US
Tg @ 6 & 12mo then annually
RI scans q 12mo
Periodic CXR/ CT chest
For locoregional recurrences → surgery
followed by RI
• Tg rise >10ng/ml → RI therapy with 100150mCi
Thyroid Carcinoma
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Follicular carcinoma represent 10-20%
• Prognostic factors include size, age, metastasis
• Witte et al., report L.N., size, stage, mets, sex
Advised total thyroidectomy + L.N. dissection and
ipsilateral or bilateral L.N. dissection for T3, T4
Follicular lesion
Follicular
TSH high → Thyroxine/Surg
TSH normal → Surgery
TSH low → Thyroid scan hot
cold
Approach to thyroid nodule
(Follicular on lobectomy)
< 1cm → observe/ reresect
Invasive
Follicular carcinoma
on lobectomy
Further local and metastatic
work up
> 1 cm → completion
thyroidectomy
followed by I 131
Approach to a thyroid nodule
Medullary carcinoma
Medullary on FNA
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Calcitonin levels
CEA
Pheo screening
Serum calcium
Screen for RET protooncogene
• Neck US