1. Hua G, Hier M, Forest VI, Mlynarek A, Payne R.
One-year experience after adapting to the 2015 American Thyroid Association guidelines for differentiated thyroid cancer at the Jewish General Hospital
Hua G, Hier M, Forest VI, Mlynarek A, Payne R.
Otolaryngology – Head & Neck Surgery
Faculty of Medicine, McGill University, Montreal, QC, Canada
Introduction
Results
Conclusions
In the 2015 American Thyroid Association (ATA) guidelines for differentiated thyroid carcinoma, several new recommendations pertaining to the indications for biopsy of a thyroid nodule were suggested.
The guidelines now recommend abstaining from performing a biopsy in thyroid nodules <1.5cm unless the ultrasound examination identifies suspicious characteristics – whereas the previous 2009 guidelines recommended a biopsy for all nodules ≥1cm.
Fig. 1 Algorithm for evaluation and management of patients with thyroid nodules based on US pattern and FNA cytology; ATA Thyroid Nodule/DTC Guidelines 2015.
This study suggests that, at our institution, patients with nodules <1.5cm who are selected for thyroidectomy are at a higher risk for malignancy and more aggressive disease when compared to patients with larger nodules.
These findings may be a result of adapting to the 2015 ATA guidelines for differentiated thyroid carcinoma.
Contact:
Richard J. Payne, MD, MSc, FRCSC
Jewish General Hospital and McGill University
3755 Côte Ste Catherine, Suite E903
Montreal, QC H3T 1E2 Canada
Table 1. Patient and Nodule Characteristics of the Study Cohort
Variable
All
Nodules ≥1.5cm
Nodules <1.5cm
p-value
Total (%)
313
258 (82.43)
55 (17.57) -
Mean age (range), years
(20-89)
(20-89)
(24-75)
0.1761
Sex (%) Male
72 (23.00)
60 (23.26)
12 (21.82)
Female
241 (77.00)
198 (76.74)
43 (78.18)
1.0000
Mean nodule size on U/S (range), cm
2.836 ( )
3.203 ( )
1.115 ( )
<0.0001
Bethesda Classification (%) I (Non-diagnostic)
8 (2.56)
8 (3.10)
0 (0)
0.3588
II (Benign)
33 (10.54)
31 (12.02)
2 (3.64)
0.0880
III (AUS/FLUS)
74 (23.64)
67 (25.97)
7 (12.73)
0.0366
IV (FN/SFN)
34 (10.86)
32 (12.40)
0.0589
V (Suspicious for malignancy)
67 (21.41)
58 (22.48)
9 (16.36)
0.3688
VI (Malignant)
97 (30.99)
62 (24.03)
35 (63.64)
Extent of Surgery (%) Hemi-/Subtotal Thyroidectomy
147 (46.96)
133 (51.55)
22 (40.00)
Total Thyroidectomy
166 (53.04)
125 (48.45)
33 (60.00)
0.1382
Final Pathology (%) Benign
85 (27.16)
79 (30.62)
6 (10.91)
Malignant
228 (72.84)
179 (69.38)
49 (89.09)
0.0024
Single nodule
137 (43.77)
113 (43.79)
24 (43.64)
Multifocal disease
176 (56.23)
145 (56.20)
31 (56.36)
Aggressive Features
65 (20.77)
47 (18.22)
18 (32.73)
0.0266
AUS/FLUS: atypia of undetermined significance/follicular lesion of undetermined significance; FN/SFN: follicular neoplasm/suspicious for follicular neoplasm.
“Aggressive Features” denote the presence lymph node metastasis and/or extra-thyroidal extension.
References
Haugen BR, Alexander EK, Bible KC, Doherty GM, Mandel SJ, Nikiforov YE, et al American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid : official journal of the American Thyroid Association. 2016;26(1):1-133.
Roti E, degli Uberti EC, Bondanelli M, Braverman LE. Thyroid papillary microcarcinoma: a descriptive and meta-analysis study. European journal of endocrinology. 2008;159(6):
Roh JL, Kim JM, Park CI. Central cervical nodal metastasis from papillary thyroid microcarcinoma: pattern and factors predictive of nodal metastasis. Annals of surgical oncology. 2008;15(9):
Ito Y, Miyauchi A, Inoue H, Fukushima M, Kihara M, Higashiyama T, et al. An observational trial for papillary thyroid microcarcinoma in Japanese patients. World journal of surgery. 2010;34(1):28-35.
Giordano D, Gradoni P, Oretti G, Molina E, Ferri T. Treatment and prognostic factors of papillary thyroid microcarcinoma. Clinical otolaryngology : official journal of ENT-UK ; official journal of Netherlands Society for Oto-Rhino-Laryngology & Cervico-Facial Surgery. 2010;35(2):
Chow SM, Law SC, Chan JK, Au SK, Yau S, Lau WH. Papillary microcarcinoma of the thyroid-Prognostic significance of lymph node metastasis and multifocality. Cancer. 2003;98(1):31-40.
Table 2. Nodule Characteristics Stratified by Size and Bethesda Classification n
Malignant (%)
Aggressive Features (%)
Bethesda
Nodules <1.5cm
Nodules >1.5cm
p-value I 8
0.3588
0 (-)
4 (50.00) -
0 (0) II 2 31
0.0880
5 (16.13)
1.0000
III 7 67
0.0366
3 (42.86)
39 (58.21)
0.4570
3 (4.48) IV 32
0.589
2 (100)
21 (65.63) V 9 58
0.3688
9 (100)
48 (82.76)
0.3353
3 (33.33)
12 (20.69)
0.4075 VI 35 62
<0.0001
35 (100)
62 (100)
15 (42.86)
32 (51.61)
0.5261
Total 55
258
49 (89.09)
179 (69.38)
0.0024
18 (32.73)
47 (18.22)
0.0266
Aim
The aim of this study was to present the experience at the Jewish General Hospital since the guidelines’ implementation.
Fig. 2 Artist’s Rendition of a Thyroid Gland; verymom.com.
Methods
Of 313 patients, 228 (72.8%) were malignant on final pathology. 55 of 313 (17.6%) had a nodule <1.5cm.
These smaller nodules were also more likely to present aggressive features than larger ones (32.7% vs. 18.2%; p=0.0266).
Nodules <1.5cm were more likely to be malignant on biopsy (63.6% vs. 24.0%; p<0.0001) and on final pathology (89.1% vs. 69.4%; p=0.0024), compared to nodules ≥1.5cm.
46 of 46 (100%; 95% CI [0.908, 1.000]) nodules <1.5cm with Bethesda IV-VI were malignant on final pathology, compared to 131 of 152 (86.2%) of nodules ≥1.5cm with Bethesda IV-VI (p=0.0047).
A retrospective study of 313 consecutive patients undergoing thyroidectomy from 2015 to 2016 was performed.
Patients’ final pathology was compared to their thyroid nodule size on pre-operative ultrasound, biopsy result, age, sex, and extent of surgery.