Overall Survival of Papillary Thyroid Carcinoma Patients: A Single-Institution Long-Term Follow-Up of 5897 Patients

INTRODUCTION: Papillary thyroid carcinoma (PTC) generally shows an excellent prognosis except in cases with aggressive backgrounds or clinicopathological features. Although the cause-specific survival (CSS) of PTC patients has been extensively investigated, the overall survival (OS) of these patients is unclear. We herein investigated both the OS and CSS of a large PTC patient series. MATERIALS AND METHODS: We enrolled 5897 PTC patients who underwent initial surgery between 1987 and 2005 (658 males and 5339 females; median age 51 years). Their median postoperative follow-up period was 177 months. Univariate and multivariate analyses for OS and CSS assessed the effects of gender, older age (≥55 years), distant metastasis at diagnosis (M1), significant extrathyroid extension, tumor size (cutoffs 2 and 4 cm), large node metastasis (N ≥ 3 cm), and extranodal tumor extension. RESULTS: To date, 387 patients (7%) in this series have died from various causes, including 117 (2%) due to PTC. The 10-, 15-, and 20-year OS rates are 97, 95, and 90%, respectively. Older age and M1 were important prognostic factors for OS and CSS. Older age was a more significant factor than M1 for OS and vice versa for CSS. In the older patients, M1 was a prominent prognostic factor for both OS and CSS. In the young patients, M1 had less prognostic impact than in the older patients, and the prognostic values of M1 and N ≥ 3 cm for OS and CSS were identical and similar, respectively. CONCLUSIONS: The most important prognostic value for OS was patient age, indicating that PTC is generally indolent. However, the control of distant metastasis in older patients remains a future challenge in order to further improve their OS and CSS. PTC of ≥3 cm in young patients should be carefully followed, even in the absence of metastases, and these patients should undergo aggressive therapies for recurrent lesions and metastases.