Improving the prediction of persistent and recurrent differentiated thyroid cancer using the American Thyroid Association 2015 risk stratification system

• Published in: Hormones (Athens, Greece) Greece), 2021-12, Vol.20 (4), p.761-768
• Main Authors: Markantes, Georgios K., Karakioulaki, Meropi, Papanikolopoulou, Stavroula, Theodoropoulou, Anastasia, Markou, Kostas B., Vagenakis, Apostolos G., Spyridonidis, Trifon, Goulis, Dimitrios G., Michalaki, Marina A.
• Format: Article
• Language: English
• Subjects: Endocrinology; Female; Humans; Iodine Radioisotopes; Medicine; Medicine & Public Health; Metabolic Diseases; Neoplasm Recurrence, Local; Original Article; Retrospective Studies; Risk Assessment; Thyroglobulin - physiology; Thyroid Neoplasms - surgery; Thyroid Neoplasms - therapy; Thyroidectomy
• ISSN: 1109-3099; 2520-8721
• DOI: 10.1007/s42000-021-00313-2

Purpose The 2015 American Thyroid Association risk stratification system (ATA RSS) is used in patients with differentiated thyroid carcinoma (DTC) to assess their risk of persistent/recurrent disease. Our aims were to validate the 2015 ATA RSS in a registry of DTC patients and to examine whether the addition of factors not included in it, such as pre-radioactive iodine therapy stimulated thyroglobulin (pre-RAI sTg), gender, and age could increase its predictive ability. Methods We studied 403 patients with DTC, treated at a tertiary center from 1990 to 2018 and subjected to total thyroidectomy. All patients had received RAI therapy, except those with low-risk papillary microcarcinoma. Results Of our patients, 81.9% were women and 91.1% had papillary thyroid carcinoma. After a median follow-up of 5.0 years, 53 cases of persistent and 21 cases of recurrent disease were recorded. The proportion of variance explained (PVE) regarding the outcome (presence or absence of recurrent/persistent disease) using the 2015 ATA RSS alone was 18.3% (persistence) and 16.9% (recurrence), increasing to 74.4% and 52.0%, respectively, when pre-RAI sTg was added to the logistic regression model. Gender and age were not associated with the disease outcome. In ROC analysis, pre-RAI sTg had a high predictive value for persistent (AUC 0.983, 95% CI 0.962–1.000) and recurrent disease (AUC 0.856, 95% CI 0.715–0.997). The optimal cut-offs and sensitivity, specificity, and positive and negative predictive value for pre-RAI sTg were the following: for persistence 12.75 ng/ml, 100%, 90.5%, 64%, and 100%, and for recurrence 8.05 ng/ml, 77.8%, 85.5%, 36.8%, and 97%. Conclusions The 2015 ATA RSS displayed moderate performance in predicting recurrent/persistent disease in patients with DTC, which improved with the inclusion of pre-RAI sTg values; pre-RAI sTg was an independent predictor of the disease outcome, with high negative prognostic value.