Does Extracapsular Extension Impact the Prognosis of Papillary Thyroid Microcarcinoma?
Extracapsular (EC) extension is a pejorative factor in papillary thyroid carcinoma (PTC). However, the impact of EC extension in microcarcinoma (micro-pT3) remains controversial, and all pT3 patients are currently considered to be at high risk of recurrence.
This study sought to determine the risk of recurrence in patients with micro-pT3 and to compare their outcomes with other pT3 (macro-pT3) and low-risk patients.
Patients and Methods
All consecutive patients who received surgery for PTC in our department from January 1978 to December 2011 were included in this study. We compared three patient groups: micro-pT3 (≤10 mm with EC extension), macro-pT3, and low risk, including pT1a-b s N0-x, pT1a-b m N0-x, and pT2 N0-x. Total thyroidectomy was performed with lymph node (LN) dissection in most cases, and radioiodine therapy was administered as needed. The median follow-up period was 6.7 years.
A total of 2,482 patients were included in this study, including 178 micro-pT3 patients, 533 macro-pT3 patients, and 1,771 low-risk PTC patients. Recurrence was documented in 14 (7.9 %) micro-pT3 patients, 124 (23.3 %) macro-pT3 patients, and 36 (2 %) low-risk PTC patients. The micro-pT3 patients with LN metastases (N1) demonstrated a higher recurrence rate than the N0-x patients (14.8 vs. 4.8 %; p < 0.01), whereas the risk of recurrence among the T2 N0-x (5 %) and micro-pT3 N0-x (4.8 %) patients was similar (p = 0.95).
Micro-pT3 N1 patients are at high risk of recurrence and should be treated aggressively. Because the outcomes of the micro-pT3 N0-x patients were similar to those of the low-risk PTC patients (pT2 N0-x), we suggest that micro-pT3 N0-x should be treated in a similar manner, with low-dose iodine-131 and recombinant human thyrotropin.
KeywordsPapillary Thyroid Carcinoma Total Thyroidectomy Multinodular Goiter Radioiodine Therapy Papillary Thyroid Carcinoma Patient
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