Prognostic factors for differentiated thyroid carcinoma and review of the literature.

OBJECTIVE: Prognostic factors of differentiated thyroid carcinoma (DTC) are analyzed to justify the diagnostic and therapeutic modalities of DTC in current practice.

METHODS: Patients undergoing curative resection for histologically diagnosed DTC (n = 150) were consecutively enrolled, and the clinical and pathological data were retrospectively reviewed.

RESULTS: The DTC patient cohort consisted of 113 females (75.3%; mean age at the time of onset, 40.1 ± 12.0 yr) and 37 males (24.7%; 47.5 ± 16.2 yr). The pathological types of DTC included papillary thyroid carcinoma (n = 131, 87.3%) and follicular thyroid carcinoma (n = 19, 12.7%). The follow-up period ranged from 4.2 to 31 years, in which period 140 (93.3%) patients survived, 30 (20.0%) patients relapsed, and 10 (6.7%) patients died of DTC. Surgical procedures used for the curative resection consisted of near-total or subtotal thyroidectomy (n = 83, 55.3%), partial thyroidectomy (n = 64, 42.7%) and total thyroidectomy (n = 3, 2.0%). Out of those patients undergoing concomitant lymph node dissection (n = 63, 42.0%), 45 patients (71.4%) had detectable lymph node metastases. Postoperatively, 12 patients (8.0%) received external beam radiotherapy, 16 patients (10.7%) received chemotherapy, 37 patients (24.7%) received 131I therapy, and 66 patients (44.0%) received additional long-term L-T4 or thyroid hormone treatment. Age of onset, tumor size at initial visit, and rate of early metastasis showed statistically significant differences between the mortality group and the survival group (P <0.05) and between the recurrence group and the recurrence-free group (P <0.05).

CONCLUSIONS: Age, tumor size at initial visit, and early metastasis are prognostic factors for DTC, requiring a stratified management in clinical practice.