Prognostic Value of Cervical Lymph Node Metastases in Papillary Thyroid Carcinoma.
Michael Rivera, Ian Ganly, Nora Katabi, Weimin Fu, Ashok Shaha, Jatin P Shah, James Fagin, Michael Tuttle, Ronald Ghossein. Memorial Sloan-Kettering Cancer Center, NYC, NY; Memorial Sloan-Kettering Cancer Center, NY, NY
Background: The impact of cervical lymph node (LN) metastases (M) on survival in papillary thyroid carcinoma (PTC) is controversial. Our aim is to assess the prognostic value of multiple histologic parameters associated with LNM in PTC in order to better stratify patients for therapy.
Design: All PTC patients with LNM at presentation identified between 1980 and 2000 were analyzed. A meticulous histopathologic examination of the primary tumor and associated LNM was undertaken. The histopathologic data was correlated with outcome.
Results: 246 patients satisfied the inclusion criteria with a median age of 36 years and a median primary tumor size of 1.9 cm.There were 136 (55.5%) classical PTC, 23 (9.5%) follicular variant PTC, 44 (18%) tall cell PTC, 35 (14%) microcarcinoma PTC and 8 (3%) PTC of other subtype. Extra-thyroid extension was found in 156 (64%) of cases and positive margins in 46 (19%).The median number of metastatic LN was 6. The median size of the largest metastatic LN was1.3 cm. Extra-nodal extension was present in 75 (32%) of cases. Median follow up was 10.8 years. In the whole study population, the presence of >3 metastatic nodes was along with older age and extensive extra-thyroid extension an independent predictor of decreased recurrence free survival (RFS) (p=0.03). The number of metastatic nodes (>3) remained an independent prognostic factor for RFS in young individuals (<45 years) lowering RFS from 97% to 88% at 10 years (p=0.05). In patients < 45 years, none of 45 cases with 1-2 metastatic LN recurred including 26 patients without radioactive iodine (RAI) therapy with a median follow up of 12.99 years. In patients 45 years and older, the presence of >5 metastatic LN was an independent predictor of neck RFS (p=0.04) decreasing RFS from 94% to 75% at 10 years. In this older population, patients with extra-nodal extension had a lower disease specific survival (90% at 10 years) than those without (100% at 10 years, p=0.008).
Conclusions: 1) The number of metastatic LN is an independent predictor of recurrence in all patients and identifies a subset of young patients with excellent prognosis who do not need RAI therapy. 2) Extra-nodal extension predicts DSS in older individuals 3) The number of metastatic LN and the presence of extra-nodal extension should be included in the pathology report of PTC in order to help guide therapy.
Monday, February 28, 2011 8:00 AM
Platform Session: Section H 1, Monday Morning