Authors: Yasuhiro Ito Chisato Tomoda Takashi Uruno Yuuki Takamura Akihiro Miya Kaoru Kobayashi Fumio Matsuzuka Kanji Kuma Akira Miyauchi
Publish Date: 2006/01/12
Volume: 30, Issue: 5, Pages: 780-786
Abstract
Extrathyroid extension has been recognized as a prognostic factor in papillary thyroid carcinoma In the most recent version of the UICC TNM classification system extrathyroid extension has been classified into two grades minimal extension extension to sternothyroid muscle or perithyroid soft tissues and massive extension extension to subcutaneous soft tissue larynx trachea esophagus or recurrent laryngeal nerve In this study we investigated the prognostic significance of each of the two types of extensionOne thousand and sixtyseven patients with papillary thyroid carcinoma without distant metastasis at surgery who underwent surgical treatment in Kuma hospital between 1990 and 1995 and had been followed postoperatively for 60 months or more were enrolled in this study The grading of extrathyroid extension was based on both pathological findings and intraoperative surgical findingsIn univariate analysis although patients with massive extension showed a significantly worse relapsefree survival RFS rate than those with no or minimal extension P 00001 there was no difference in the RFS rate between patients with no extension and those with minimal extension Among patients with massive extension the RFS rate tended to be worse in those with posterior extension than in those with anterior extension P = 00562 Furthermore the RFS rate of patients with massive posterior extension only to the recurrent nerve demonstrated a better RFS rate than those with extension to other posterior organs P = 00052 Multivariate analysis demonstrated that massive extrathyroid extension is recognized as an independent prognostic factor for RFS P = 00003These findings suggest that 1 upgrading of T category for tumors with massive extension is appropriate whereas that for tumors with only minimal extension is not and 2 careful surgical treatment and postoperative followup are required for tumors with massive extension to posterior organs other than the recurrent laryngeal nerve
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