Aggressiveness of therapy and prognosis of patients with Hürthle cell papillary thyroid carcinoma.

Hürthle cell papillary thyroid carcinoma (HCPTC) has been studied separately from other types of thyroid carcinoma in relatively few studies. The aim of our study was to determine the factors associated with the survival of patients with HCPTC in Slovenia, an iodine-deficient region. A total of 1552 patients with thyroid carcinoma were seen at our institute during the period of 1976-2003; of them, 42 patients (33 females, 9 males; age 10-85 years, median 56.5 years) had histopathologically verified HCPTC. The data on the patients' gender, age, disease history, extent of disease, morphologic characteristics, therapy, locoregional control, disease-free interval, and survival were collected. The statistical correlation between possible prognostic factors and the disease-free interval and survival was analyzed by chi2 test and log rank analysis. The tumor diameter ranged from 1 to 9 cm (median, 3 cm). Extrathyroid tumor growth was found in 19 patients, lymph node metastases in 13 patients, and distant metastases in 2 patients. Primary treatment consisted of total or near-total thyroidectomy (39 patients), lobectomy (2 patients), radioiodine ablation of the thyroid remnant (37 patients), external irradiation (14 patients), and chemotherapy (3 patients). Locoregional recurrence was diagnosed in four patients, and dissemination in 1 patient during the follow-up period of 0.75-20 years (median, 5.5 years). Three patients died of thyroid carcinoma during the follow-up period. The 5-year and 10-year survivals were 94% and 87%, respectively. The 5-year and 10-year disease-free intervals were 93% and 81%, respectively. The factors correlated with the survival were: age, extrathyroid tumor growth, primary tumor stage, and regional and distant metastases. Although extrathyroidal tumor growth was found in 45% of the patients with HCPTC, our patients had a favorable prognosis. Long-term survival and locoregional control of disease are likely after the radical tumor resection, radioiodine ablation of the thyroid remnant, and external irradiation.