Prognostic factors for intrathyroidal papillary carcinomas – a multivariate analysis

Aim: to examine prognostic significance of patient-related, tumor-related and treatment-related factors for intrathyroidal papillary thyroid carcinomas (PTC), via multivariate analysis.

Material and methods. This study included 153 patients with intrathyroidal PTCs (pT1/pT2/pT3) surgically treated in our Institution during two-decade period. Patients with locally invasive tumors (pT4) and initial distant metastases (M1) were excluded. Parameters of interest were: gender (male; female), age (<=45; >45 years), tumor size (pTNM classification WHO 1984), multifocality (no; yes), histological type of PTC (pure; microcarcinoma; follicular; poorly differentiated), presence of lymphonodal metastases (pN1a; ipsilateral-pN1b; contralateral-pN1b; total), surgery extent (total thyroidectomy; total thyroidectomy with lymphonodal dissections). Univariate and multivariate analysis of all parameters was performed in order to distinguish factors of significance for disease-free survival (DFS) and cancer-specific overall survival (cs-OS).

Results. In the follow-up, 10% of patients had locoregional or distant relapse, while 5.2% died due to PTC. Univariate analysis distinguished older age, male gender, tumors over 4cm in diameter, multifocality and poorly differentiated PTC-types as unfavorable prognostic factors for cs-OS. DFS was significantly shorter in males vs. females, as well as in patients with multifocal vs. solitary PTC. Tumor multifocality was unfavorable prognostic factor for both DFS and cs-OS. Independent prognostic factors for intrathyroidal PTCs, based on Cox multivariate analysis, were multifocality and gender for DFS, and multifocality and age at diagnosis for cs-OS.

Conclusions. Prognostic factors define risk groups within population of differentiated PTCs providing timely, adequate treatment and opportunity for longer quality life of patients with PTCs.