Adi Guy1, Dania Hirsch, Tzippy Shohat, Gideon Bachar, Amit Tirosh, Eyal Robenshtok, Ilan Shimon, Carlos A Benbassat. 1. Endocrine Institute (A.G., D.H., A.T., E.R., I.S., C.A.B.), Department of Otolaryngology Head and Neck Surgery (G.B.), and Statistics Unit (T.S.), Rabin Medical Center, Beilinson Campus, Petah Tiqwa, Israel 49100; and Sackler Faculty of Medicine (A.G., D.H., G.B., A.T., E.R., I.S., C.A.B.), Tel Aviv University, Tel Aviv, 69978, Israel.
Abstract
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 I(131) 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.
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 I(131) 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.