Transcript FNA-TG of Neck Nodes in Patients with PTC is Affected by Serum

FNA-TG of Neck Nodes in the Patients
with PTC is Affected by Serum
Concentration of TSH And
Thyroglobulin
JH Moon1, YI Kim2, JA Lim3, HS Choi3, SW Cho3, KW Kim4, JC
Paeng2, YJ Park3, KH Yi5, DJ Park3, J-K Chung2
1Department
of Internal Medicine, Seoul National University Bundang Hospital, Seoul National
University College of Medicine
2Department
of Nuclear Medicine, Seoul National University College of Medicine
3Department
of Internal Medicine, Seoul National University Hospital, Seoul National University
College of Medicine
4Seoul
National University Healthcare System Kangnam Center, Seoul National University
College of Medicine
5SMG-SNU
Boramae Medical Center, Seoul National University College of Medicine
Statement of interest: None
FNA-Tg
• Measuring the concentration of thyroglobulin directly in
the washout of the needle used in FNAC
Various cut-off value (0.93-50 ng/ml)
•
Factors affecting FNA-Tg and resulting in the
discrepancy between the final diagnosis and FNA-Tg
Study objectives
• To suggest an optimal cut-off value of FNA-Tg to
determine malignant LN with a large number of cases
from PTC patients
• To find out parameters affecting FNA-Tg and the
diagnosis using FNA-Tg
- Evaluation of discrepant results
Subjects and Methods
Patient characteristics and FNA-Tg
according to the final diagnosis
Final diagnosis
p-value
Malignancy
Benign
190
338
30.5/69.5
24.3/75.7
0.228*
52.6 ± 15.0
49.5 ± 12.4
0.017†
18.0 ± 10.9
13.5 ± 11.4
< 0.001†
Multiplicity (yes/no, %)
69.5/30.5
63.1/36.9
0.203*
Lymph nodes metastasis (yes/no, %)
87.0/13.0
59.3/40.7
< 0.001*
Lymphatic invasion (yes/no, %)
51.0/49.0
27.2/72.8
< 0.001*
Vascular invasion (yes/no, %)
32.3/67.7
15.7/84.3
< 0.001*
Extrathyroid extension (yes/no, %)
90.3/9.7
71.6/28.4
< 0.001*
521.2 (3676.8)
0.1 (0.2)
< 0.001‡
1.4 (9.5)
0.2 (0.4)
< 0.001‡
333.3 (2397.7)
0.0 (0.3)
< 0.001‡
Lymph nodes (n)
Patients
Sex (male/female, %)
Age (year)
Primary tumor
Size (mm)
FNA-Tg (ng/ml)
Serum Tg (ng/ml)
FNA-Tg - Serum Tg (ng/ml)
Data are expressed as mean ± SD or median (interquatile range).
FNA-Tg, thyroglobulin in the needle washout fluid of fine-needle aspiration cytology
*Derived from a Chi-square test.
†
Derived from a Student's T test.
‡
Derived from a Mann-Whitney U test.
Validation of Cut-off value
(FNA-Tg vs. FNA-Tg – serum Tg)
Cut-off value
Included lymph nodes
FNA-Tg
(ng/ml)
Sensitivity (%)
Specificity (%)
93.8
88.9
87.4
89.7
94.1
95.0
87.3
95.3
94.2
95.5
87.7
96.1
93.2
95.9
85.7
96.7
FNA-Tg - serum Tg
(ng/ml)
1.11
Surgically resected LNs only (n =165)
0.15
Surgically resected LNs and
LNs F/U for 36 months or more (n = 255)
Surgically resected lymph nodes and
LNs F/U for 24 months or more (n = 377)
Surgically resected lymph nodes and
LNs F/U for 12 months or more (n = 528, all cases)
1.11
0.40
0.99
0.40
1.0
0.48
Diagnostic performance
Diagnosis modality
Sensitivity (%)
Specificity (%)
FNAC
83.6*
98.2*
FNA-Tg (cut off value, 1.0 ng/ml)
93.2*
95.9*
FNA-Tg (1.0 ng/ml) + FNAC
98.4
94.4
*p < 0.05 vs. FNA-Tg + FNAC, derived from a McNemar test.
ROC of FNA-Tg for Dx of malig. LN. in all cases
Optimal cut-off value: 1.0 ng/ml
AUC: 0.967 (95% CI 0.949-0.984)
The cut-off value of FNA-Tg according
to the presence of thyroid gland
Prior to thyroidectomy
After thyroidectomy
2.24 ng/ml (95.0%, 96.3%)
1.09 ng/ml (90.8%, 96.5%)
AUC: 0.987 (95% CI 0.975-0.999)
AUC: 0.956 (95% CI 0.932-0.980)
FNA-Tg, serum Tg and TSH according to
the presence of thyroid gland
FNA-Tg
201.0 (3884.77)
0.1 (2.90)
Correlation of FNA-Tg with serum Tg or
TSH
All cases
Malignant cases
Benign cases
Serum Tg
Correlated
ρ = 0.383
p < 0.001
Correlated
ρ = 0.228
p = 0.004
Correlated
ρ = 0.210
p < 0.001
Serum TSH
Correlated
ρ = 0.210
p < 0.001
Correlated
ρ = 0.335
p < 0.001
Not correlated
ρ = 0.075
p = 0.183
Correlation of FNA-Tg with TgAb
0.1 (7.15)
TgAb -
0.3 (71.46)
TgAb +
Serum TSH and Tg on the diagnosis from
FNA-Tg
Logistic regression analysis of serum TSH and Tg with the diagnosis using FNA-Tg cut-off
value 1.0 ng/ml
Odd ratio
95% confidence interval for odds ratio
Lower
Upper
p-value
Serum TSH
1.171
1.038
1.321
0.01
Serum Tg
1.035
1.012
1.059
0.003
The dependent variable was the diagnosis using ENA-Tg cut off value 1.0 ng/ml, and the independent variables
were serum TSH and Tg levels.
Logistic regression analysis of serum TSH suppression and serum Tg presence with the
diagnosis using FNA-Tg cut-off value 1.0 ng/ml
Odd ratio
95% confidence interval for odds ratio
Lower
Upper
p-value
No serum TSH suppression
2.871
1.794
4.595
< 0.001
Serum Tg presence
1.980
1.261
3.109
0.003
The dependent variable was the diagnosis using ENA-Tg cut off value 1.0 ng/ml, and the independent variables
were no serum TSH suppression (serum TSH ≥ 0.4 mU/l) and serum Tg presence (serum Tg ≥ 0.2 ng/ml).
Clinical implications
Summary
• Optimal cut-off value of FNA-Tg was 1.0 ng/ml
• FNA-Tg + FNAC showed better diagnostic rate than FNAC
or FNA-Tg alone.
• FNA-Tg was correlated with serum Tg and TSH, not with
TgAb.
• The diagnosis using FNA-Tg can be affected by serum TSH
and Tg levels.
Conclusion
• The combination of FNAC and FNA-Tg can
complement the low sensitivity of FNAC alone.
• TSH suppression and the presence of serum Tg
should be considered for accurate FNA-Tg-based
diagnosis of metastatic malignant LNs in PTC
patients.