Prognostic significance of young age in papillary thyroid carcinoma: analysis of 5,733 patients with 150 months' median follow-up.

Among the several prognostic factors of papillary thyroid carcinoma (PTC), age is the most prominent. It is well known that elderly PTC patients have poorer prognoses. Here we investigated the prognostic impact of young age in univariate and multivariate analyses. We retrospectively analyzed 5,733 PTC patients without distant metastasis at presentation, who underwent initial surgery at Kuma Hospital. The median follow-up period was 150 months. We classified the patients into three groups: young (< 30 years), middle-aged (30-59), and older patients (≥ 60 years). The tumor size was larger and clinical node positivity was higher in the young patients, and significant extrathyroid extension was higher in the older patients compared to the other two groups. In the univariate analysis, the young patients showed poorer extrathyroidal locoregional and distant recurrence rates than the middle-aged patients, but not cause-specific survival rates. In the multivariate analysis, age < 30 years was an independent or marginal predictor of extrathyroidal locoregional and distant recurrence, but not of carcinoma-related death. Age ≥ 60 years independently affected PTC recurrence and death. Taken together, we should carefully treat young PTC patients because of the likeliness of extrathyroidal locoregional and distant recurrence, which may not be life-threatening.