Natural history and clinical outcome of differentiated thyroid carcinoma: a retrospective analysis of 1503 patients treated at a single institution

Abstract

BackgroundThe study evaluates clinical presentation and outcome of differentiated thyroid cancer (DTC) on a large series of patients homogeneously managed. Patients and methodsA cohort of 1503 DTC followed according to a standardized protocol entered the study. Main outcome measures were clinical presentation at the diagnosis, survival, morbidity and prognostic risk factors. ResultsMedian age at diagnosis was 46 years. Papillary cancer and low pathological tumor–node–metastasis stages represented >80% of cases. Cancer specific survival at 5, 10 and 15 years was 98.6%, 94.7% and 87.4%; 10-year disease-free and progression-free survivals were 96.8% and 17.1%, respectively. Cancer-specific mortality rate was 2.5% [95% confidence interval (CI) 1.7% to 3.4%], recurrence rate was 0.6 % while morbidity rate was 12.6% (95% CI 11% to 14%). Response to radioiodine treatment is the strongest predictor of a good outcome in multivariate analysis (hazard ratio 211, P < 0.0001). Other independent predictor variables are sex, age, histology and distant metastases for survival and metastases for morbidity. ConclusionsA rigorous initial therapeutic approach leads to a better survival and a very low morbidity. Patients who do not respond to radioiodine treatment have a worse prognosis.