Maria Chiara Zatelli

1
Ferrara, 20 gennaio 2012
Analisi genetica del nodulo tiroideo implicazioni
per lesecuzione del linfonodo sentinella
Maria Chiara Zatelli
Sezione di Endocrinologia Dip. di Scienze
Biomediche e Terapie Avanzate Università di
Ferrara Direttore Prof. Ettore degli Uberti
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molecular marker?
a molecular marker (genetic marker) is a DNA
sequence associated to a part of the genome, used
in molecular biology and biotechnology
experiments to identify a very highly specific
DNA sequence
What relevance in thyroid nodules?
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Fine-needle aspiration biopsy (FNAB) is currently
the most sensitive and specific tool for the
presurgical differential diagnosis of thyroid
malignancy but has also substantial limitations
Eszlinger et al. Mol Cell Endocrinol 201032229
75 benign lesions
5 malignant lesions
20 follicular proliferation
FA
FTC
fvPTC
thyroid surgery
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MOLECULAR BIOLOGY study of biology at molecular
level
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Highly feasible in clinical settings
somatic mutation analysis
rearrangement studies
BRAF N-RAS H-RAS K-RAS
RET/PTC1 RET/PTC3 PPARg/PAX8
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PAPILLARY CARCINOMA
DNA
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• do they improve diagnosis?

genetic tests
BRAFV600E molecular test Cytology Cytology BRAF BRAF Cytology BRAF Cytology BRAF
Sensitivity 100 77.3 89.6 64.0 89.6 86.7
Specificity 36.4 98.8 95.5 100 95.5 98.8
PPV 92.9 92.1 99.4 100 99.4 92.9
NPV 100 95.9 52.5 93.7 52.5 97.5
Accuracy 93.3 95.4 90.2 95.4 90.2 96.9
K value 0.510.11 0.810.02 0.630.07 0.760.05 0.630.07 0.880.01
Kim et al. J Clin Endocrinol Metab, 2011, 96658
Zatelli et al . Eur J Endocrinol 2009, 161467
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• do they improve diagnosis?

genetic tests
BRAFV600E molecular test
Kim et al. J Clin Endocrinol Metab, 2011, 96658
BRAF mutation analysis may help especially in
small nodules
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BRAFV600E molecular test
Section of Endocrinology University of Ferrara
1856 pz
(1436 ? 420 ?) age 52 0,32 (12-73)
Biomolecular analysis
suspected 829
2421 FNAs
US clinical evaluation
NON suspected 1529
Pathology
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cytology S NS
tot 829 34,2 1592 65,7
Malignant rate 115 13,9 103 6,5
PTC/malignant 112 97,4 98 95,1
BRAF 64 7,7 50 3,1
BRAF / Malignant 64/115 55,7 50/103 48,5
FNAB per se detects a high percentage of
malignant lesions in unsuspected nodules
Martina Rossi et al. submitted
All nodules should undergo FNAB
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BRAFV600E molecular test Cytology Cytology BRAF BRAF Cytology BRAF Cytology BRAF
  S NS S NS S NS
Sensitivity 76,8 69,4 56,6 51 92,9 84,7
Specificity 99,7 99,9 100 100 99,7 99,9
PPV 97,7 98,6 100 100 98,1 98,8
NPV 96,5 98 93,6 96,9 98,9 99
Accuracy 96,6 98,1 94,1 97 98,8 99
BRAF testing significantly increases FNAB
sensitivity also in nodules clinically non
suspected
Martina Rossi et al . submitted
15 PTC patients rescued by BRAF analysis
BRAFV600E molecular test increases diagnostic
sensitivity for PTC
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  BRAFV600E molecular test S NS
ACUS 26 3,1 78 4,9
PTC 6 75,0 10 37,0
BRAF 5 19,2 0 0,0
FN 35 4,2 62 1,2
PTC 5 25,0 9 23,7
BRAF 2 5,7 6 9,7
BRAF testing identifies as malignant 10 of FN
Martina Rossi et al . submitted
Indication to total thyroidectomy
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CONCLUSION -1
Thyroid molecular markers increase diagnostic
sensitivity of cytology for PTC and influence
surgical approach
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genetic tests

• any prognostic value?

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BRAFV600E molecular test
Xing et al. J Clin Oncol. 2009272977-82
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BRAFV600E molecular test PTC persistence/recurrence prediction PTC persistence/recurrence prediction
All PTC Conventional PTC
sensitivity 68 79
specificity 66 60
PPV 36 34
NPV 88 92
Xing et al. J Clin Oncol 2009 272977-82
BRAF mutationpositive patients are significantly
more likely to have PTC persistence/recurrence
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BRAF V600E genetic test
significantly reduced disease-free probability
in BRAF patients
Xing et al. J Clin Oncol. 2009272977-82
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BRAF V600E genetic test
significantly increased mortality in BRAF
patients
Elisei et al. J Clin Endocrinol Metab.
2008933943
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CONCLUSION -2
Thyroid molecular markers may predict patients
outcome
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genetic tests

• any surgical relevance ?

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BRAF mutation
103 PTC
lymph node metastases may show de novo mutations
60
50
? is not necessary for locoregional lymph node
metastasis
40
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n. of PTC
? is a significant risk factor for locoregional
lymph node metastasis
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10
Vasko et al. J Clin Endocrinol Metab 2005 90
5265
0
!! also in microPTC !!
BRAF (-) 69
BRAF () 34
20/26 BRAF LN
Lin et al. Ann Surg Oncol 2010173294
Kim et al. Ann Surg 2006244 799
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lobectomy
BRAF mutation
? surgical strategy
total thyroidectomy
lymph node dissection
no dissection
better staging
what lymphnode dissection?
High prognostic impact
extrathyroidal invasion lymph node
metastasis local neck recurrence PTC
recurrence complications
Xing Endocrine Reviews 2007 28 742
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BRAF mutation
PREDICTOR OF LYMPHNODE METASTASES
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BRAFV600E molecular test
less aggressive surgery
more aggressive surgery
neck lymph node dissection
BRAF mutation-based
decision making
risk stratification
PTC management
Xing et al. J Clin Oncol. 2009272977-82
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CONCLUSION -3
Positivity of thyroid molecular markers as
indication for sentinel lymphnode procedure
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BRAF V600E genetic test
May address patients with persistent/recurrent
disease to therapy with BRAF-specific inhibitors
Cantwell-Dorris et al. Mol Cancer Ther 2011, 10
385
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CONCLUSIONS
Thyroid molecular markers

• increase cytology diagnostic sensitivity for PTC
  
• may predict patients outcome
• influence surgical approach
• their positivity is an indication for sentinel
  lymphnode procedure

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THANKS
Section of Endocrinology Dept. of Biomedical
Sciences and Advanced Therapies University of
Ferrara
Ettore degli Uberti
Personale Medico Tecnico Infermieristico Assegni
sti di ricerca Dottorandi Studenti
Degenza Day Hospital Ambulatori
Ambulatorio Ecografia/ Agoaspirati
Laboratorio di Fisiopatologia Endocrina