Survival of differentiated thyroid carcinoma studied in 500 patients.

PURPOSE: To analyze the factors that influence survival of patients with differentiated thyroid carcinoma treated by surgical thyroidectomy, radioactive iodine, and early surgical reintervention with compartment-oriented lymphadenectomy in the case of locoregional recurrence.
METHODS: The survival of 500 patients with differentiated thyroid carcinoma was analyzed retrospectively with regard to mortality and survival rate (Kaplan-Meier). A total of 301 patients had papillary and 199 follicular thyroid carcinoma. The mean age of the 380 women and 120 men was 46.8 +/- 16.4 years at presentation. All patients were treated by surgical thyroidectomy, high-dose radioactive iodine, and early surgical reintervention with compartment-oriented lymphadenectomy in cases of locoregional recurrence, without routine adjuvant external radiotherapy of the neck. Patients were monitored up to 23 years, with a median follow-up time of 5.6 years.
RESULTS: Twenty-nine of 500 patients died, 19 of thyroid cancer. The corrected overall 5-year survival rate (Kaplan-Meier) was 0.92. Among patients with tumor stage pT1-3NO-1MO (low risk), none died of thyroid carcinoma (5-year survival rate, 0.97); in patients with tumor stage pT4 and/or M1 (high risk), the 5-year survival rate was 0.83. The cause of death was locoregional recurrence in eight and metastatic disease in 11. Using multivariate analysis, risk factors that significantly influence survival were local invasion (pT4), metastatic disease (M1), and age.
CONCLUSION: In differentiated thyroid carcinoma, the use of total surgical thyroidectomy followed by high-dose radioiodine therapy and early surgical reintervention in case of locoregional recurrence yields high survival rates, even without adjuvant external radiotherapy of the neck.