J Endocr Surg.  2019 Mar;19(1):11-17. 10.16956/jes.2019.19.1.11.

Impact of Minimal Extrathyroidal Extension on Recurrence in Papillary Thyroid Carcinoma Measuring 4 cm or Less without Clinical Lymph Node Metastasis

• Park JW
• Lee OJ
• Son SM
• Woo CG

• KMID: 2442156
• DOI: http://doi.org/10.16956/jes.2019.19.1.11

Abstract

PURPOSE
American Thyroid Association's guidelines (2015) recommend that papillary thyroid carcinomas (PTCs) ≤4 cm without extrathyroidal extension (ETE) and clinical lymph node metastasis (cLNM) can be treated by a unilateral procedure if a slightly higher risk of locoregional recurrence is accepted. The aim of the present study is to evaluate impact of minimal ETE (mETE) on locoregional recurrence in PTCs ≤4 cm without cLNM.
METHODS
The medical records of patients who underwent thyroidectomy for PTC ≤4 cm between January 1, 2007 and December 31, 2013 were retrospectively reviewed. Patients who had PTC with gross ETE and/or cLNM were excluded.-Patients with papillary thyroid microcarcinoma (PTMC) without ETE (group I; n=381) were compared with three other groups of patients: PTC 1-4 cm without ETE (group II; n=150); PTC ≤1 cm with mETE (group III; n=186); and PTC 1-4 cm with mETE (group IV; n=121). Mean follow-up period was 72.2±26.4 months.
RESULTS
Multiplicity, bilaterality, LNM, and total thyroidectomy were more common in group III and IV. Five-year disease-free survival (DFS) was 100%, 97.9%, 95.9%, and 94.9% in group I, II, III, and IV, respectively. DFS rates were significantly higher in group I compared to the other groups (P<0.01). There were no significant differences among group II, III, and IV.
CONCLUSION
Compared to PTMC without ETE, mETE in PTC ≤4 cm without cLNM may be associated with more aggressive biological behavior and increased risk of recurrence, although the increments may be relatively small.

Keyword

Papillary thyroid carcinoma; Extrathyroidal extension; Lymph node metastasis; Disease-free survival

MeSH Terms

Disease-Free Survival
Follow-Up Studies
Humans
Lymph Nodes*
Medical Records
Neoplasm Metastasis*
Recurrence*
Retrospective Studies
Thyroid Gland*
Thyroid Neoplasms*
Thyroidectomy

Figure

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  Fig. 1 Comparison of DFS of patients in control, group I, II, and III. Group I, PTC ≤1 cm without ETE; group II, 1–4 cm without ETE; group III, ≤1 cm with mETE; group IV, 1–4 cm with mETE. DFS = disease free survival; PTC = papillary thyroid carcinoma; ETE = extrathyroidal extension; mETE = minimal extrathyroidal extension. *P<0.05; †Statistically not significant.

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