Prognostic Factors for Recurrence of Papillary Thyroid Carcinoma in the Lymph Nodes, Lung, and Bone: Analysis of 5,768 Patients with Average 10‐year Follow‐up

Large lymph node metastasis showed a strong prognostic impact on carcinoma recurrence not only to the lymph nodes but also to the lung and bone, and carcinoma death. Extrathyroid extension also independently predicted these recurrences and carcinoma death, although hazard ratios were lower than for large node metastasis. Age 55 years or older, in contrast, was the strongest predictor of carcinoma death. Extranodal tumor extension did not independently affect recurrence, but it had prognostic significance for carcinoma death. These findings suggest that recurring PTC lesions of older patients and/or extranodal tumor extensions are difficult to control and very progressive.