Papillary thyroid cancer: Factors involved in restaging n1 disease after total thyroidectomy and radioactive iodine treatment

Adi Guy, Dania Hirsch, Tzippy Shohat, Gideon Bachar, Amit Tirosh, Eyal Robenshtok, Ilan Shimon, Carlos A. Benbassat

Research output: Contribution to journalArticlepeer-review


Context: The presence of cervical lymph node metastases is a strong predictor of persistent disease in papillary thyroid cancer (PTC).

Objective: The objective of the study was to investigate factors associated with improved outcome in patients with PTC and lymph node metastases.

Design: Retrospective Cohort Setting The study was conducted at a tertiary university-affiliated medical center.

Patients: Patients treated for PTC and N1 disease since 1995 participated in the study. Partial thyroidectomy, distant metastases, and poor differentiation were the exclusion criteria.

Interventions: The intervention was a data search of the Thyroid Registry.

Main Outcome Measures: Significant association of clinical and disease-related factors with persistent disease was measured.

Results: Of 800 patients treated for PTC during the study period, 182 (69% female; mean age at diagnosis 46.5± 15 y) had N1 disease (47% N1a, 53% N1b). Most (93.4%) had a classical/follicular variant; 65% had T1-2 disease; and 42.6% had extrathyroid extension. All patients were treated with total thyroidectomy and radioactive iodine (mean first dose 147± 26 mCi). Lateral neck dissection was performed in 53% patients. Mean follow-up was 9.2± 4.5 years. On regression analysis, factors significantly and independently associated with persistent disease at 1 year (94 of 182, 52%; 40% of N1a group, 59% of N1b group) were primary tumor size, focality, and extrathyroid extension and at the last follow-up (62 of 182, 34%; 27% of N1a group, 33% of N1b group), primary tumor size, 1-year stimulated thyroglobulin level, and cumulative I131 dose. Stimulated thyroglobin less than 2.1 ng/mL at 1 year predicts the absence of disease at the last follow-up with an 86% negative predictive value.

Conclusion: Patients with PTC and N1 disease treated with total thyroidectomy and radioactive iodine have a significant risk of persistent disease at early and late follow-up. The extension of the primary tumor at diagnosis appears to be the only significant predictor of persistency in these patients.

Original languageEnglish
Pages (from-to)4167-4173
Number of pages7
JournalJournal of Clinical Endocrinology and Metabolism
Issue number11
StatePublished - 1 Nov 2014


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