Papillary thyroid microcarcinoma: Prognostic factors and treatment

Background and Objectives: Within the group of patients with papillary thyroid microcarcinoma (PTMC), the prognostic factors have not been well defined and the optimal treatment has not been proved. The aim of this study was to find out the factors associated with the tumor recurrence in the patients with PTMC. Methods: A total of 228 patients with PTMC (189 females, 39 males; age 14-85 years, median 46 years) were treated at our Institute between 1975 and 2006. The data on patients' gender, age, extent of disease, pathomorphological characteristics, therapy, locoregional control, disease-free survival and disease-specific survival were collected. Statistical correlation between possible prognostic factors and the duration of disease-free interval was analyzed by univariate and Cox's multivariate survival analysis. Results: The tumor diameter ranged from 0.1 to 10 mm (mean 6.1 mm). The median length of observation was 84 months (range 1-385). During the follow-up period, the recurrence was diagnosed in 7 patients (6 locoregional and I distant). Multivariate analysis showed that tumor size and lymph node metastases were independent prognostic factors for disease-free interval. Conclusions: Longer disease-free interval was found in the patients with a tumor diameter <= 6 mm and without lymph-node metastases.