Prognostic factors in anaplastic carcinoma of the thyroid-a multivariate survival analysis of 188 patients.

Background: Multivariate studies concerning the prognosis of patients with anaplastic carcinoma of the thyroid gland are scarce. The aim of our study was to determine the prognostic factors associated with survival of patients with anaplastic carcinoma in Slovenia, an iodine-deficient region.

Methods: This retrospective study was carried out on a group of 188 patients (130 female, 58 male; median age 68 years) with anaplastic carcinoma of the thyroid who had been treated at a tertiary care centre from 1972 to 2003. For each patient, data on gender, age, disease history, extent of disease, morphological characteristics, mode of therapy, and survival were collected. Statistical correlation between possible prognostic factors and survival was analysed by univariate and Cox's multivariate analysis. Treatment modality was not included in the analysis to avoid selection bias.

Results: The median survival of all the patients was 3 (+/-0.36) months. Overall 1-year survival of our patients was 13%, and 2-year survival was 6%. Multivariate analysis showed that the patients' age, performance status, tumour growth, tumour extension and distant metastases were independent prognostic factors for the survival.

Conclusion: Patients younger than 71 years, with a good performance status and slowly growing tumours confined to the thyroid, and without distant metastases, had the best prognosis.