Prognostic Value of Early Clinical Characteristics to Predict Refractory Papillary Thyroid Cancer: An Attempt to...

Papillary thyroid cancer (PTC) is the most common form of differentiated thyroid cancer (DTC). While most cases respond to standard treatments, a subset becomes refractory to radioiodine therapy (RAIR). This study aims to develop a clinically applicable scoring system based on baseline characteristics to predict RAIR in PTC patients.

A retrospective analysis of 150 PTC patients (50 RAIR and 100 responders) was conducted at a tertiary center between 2011 and 2023. Patients were classified as RAIR if they received ≥ 600 mCi of cumulative radioiodine but exhibited disease progression. Baseline clinical, histopathological, and laboratory data were extracted. Univariate and multivariate logistic regression analyses identified significant predictors of RAIR status. A predictive scoring system was developed based on weighted odds ratios (OR), and its diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis.

Age ≥ 50 years (OR = 12.85), early serum thyroglobulin (Tg) ≥ 15 ng/mL (OR = 20.95), lateral lymph node metastasis (OR = 4.13), and early distant metastasis (OR = 29.95) were independent predictors of RAIR. The proposed 10-scale scoring system demonstrated high diagnostic accuracy (AUC = 0.94), with a score ≥ 3 predicting RAIR with 94% sensitivity and 85% specificity. A score ≥ 6 achieved 100% specificity and positive predictive value.

Our practical scoring system, based on readily available clinical and laboratory parameters, offers a clinically oriented tool for the early identification of RAIR PTC patients. Prospective multi-center validation is needed to confirm its utility in guiding treatment decisions and improving patient outcomes.