The role of thyroglobulin as a preoperative predictive marker for total thyroidectomy in thyroid cancer patients

Objective: This study aimed to investigate the predictive diagnostic role of thyroglobulin (Tg) as a preoperative tumor marker among patients at the National Cancer Center in Yemen. Analysis of 323 cases (141 malignant, 182 benign) demonstrated high diagnostic accuracy with an area under the curve (AUC) of 0.913 (95% CI: 0.879–0.946, P < 0.001). Various threshold values were evaluated, with optimal diagnostic performance observed at different cutoff points, suggesting Tg’s potential as a valuable preoperative screening tool. Method: A prospective study of 323 patients of thyroid nodule was conducted between January 2013 and March 2025. A diagnostic accuracy study was performed to analyzing the high level of preoperative Tg in 323 patients presenting with thyroid nodules in comparison with post total thyroidectomy histopathological results, where 141 patients subsequently confirmed had malignant nodule and 182 cases confirmed as benign nodule Results: Of all results of preoperative Tg level of 323 cases, we were performed the receiver operating characteristic (ROC) curve analysis to evaluate the diagnostic accuracy Tg. Multiple cutoff points were analyzed to determine optimal threshold values for clinical application. Statistical significance was set at P < 0.001. The result of The ROC curve analysis revealed excellent discriminatory power with an AUC of 0.913 (95% CI: 0.879–0.946, SE: 0.017, P < 0.001). This indicates strong diagnostic capability of Tg as a preoperative marker. Conclusion: This study demonstrates that preoperative serum Tg is a highly effective biomarker for differentiating malignant from benign thyroid nodules, supported by an AUC of 0.913 in 323 histopathological confirmed cases. While Tg’s adaptability across cutoff thresholds enhances its diagnostic utility, optimal values require context specific validation. The findings advocate integrating Tg into preoperative screening to improve risk stratification and reduce unnecessary interventions. However, broader multicenter studies are needed to confirm generalizability and establish standardized thresholds, particularly beyond the studied Yemeni cohort, to refine thyroid cancer management globally.