Preablative serum thyroglobulin as predictor of disease-free survival in differentiated thyroid cancer Importancia de la tiroglobulina sérica preablativa en la predicción de sobrevida libre de enfermedad en cancer diferenciado de tiroides

Abstract

Background: Serum thyroglobulin (sTg) is an excellent marker of persistence or recurrence of disease in differentiated thyroid cancer (DTC), however its role as prognostic factor has not been fully established. Aim: To assess the value of the prea-blative thyroglobulin (pTg) as predictor of disease-free survival in DTC. Patients and Methods: Retrospective study of 104 patients with low and intermediate risk DTC subjected to total thyroidectomy and 131iodine ablation. TSH, pTg and thyro-globulin antibodies (AbTg) were determined by chemiluminescence. Patients with distant metastases or presence of AbTg were excluded. Results were analyzed using receiving operating characteristic (ROC) curves. Results: During the 40 ± 29 months of follow-up (range 6-132), 14 of 104 (13%) patients had recurrence of disease. pTg was an independent indicator to predict disease-free survival. Using a pTg cutoff of < 10 ng/ml the negative predictive value was 99%, sensitivity 93%, specificity 82%, positive li