부산대학교 도서관

Background: The joint Union International Contre le Cancer and American Jo int Committee on Cancer (UICC/AJCC) Tumor, Node, Metastasis (TNM) staging system for differentiated thyroid cancer (DTC) involves a single age cutoff as a prognostic criterion. Because a single cutoff is a dichotomizati on of what might be a sliding scale, using multiple age cutoffs might result into a better stage definition. The aim of o ur study was to investigate if using a two-step age-based cutoff would improve the TNM staging system regarding disease-sp ecific survival (DSS). Methods: We retrospectively studied two cohorts of adult DTC patients f rom The Netherlands and Germany. DSS was analyzed for papillary (PTC) and follicular thyroid cancer (FTC ) separately, investigating several two-step age-based cutoffs for those with distant metastases; below lower threshold classified as stage I, between lower and upper threshold as stage II, and above upper threshold as stage IV. Results: We included 3074 DTC patients (77% PTC). For PTC, an age cutoff of 45 with 50 years had the best statistical model performance, while this was 25 with 40 years for FTC. How ever, differences with the optimal single age cutoffs of 50 years for PTC and 40 years for FTC were small. Conclusions: The optimal two-step age-based cutoff to predict DSS is 45 with 50 years for PTC and 25 with 40 years for FTC, rather than 55 years currently used for DTC. Although thes e two-step age-based cutoffs were marginally better from a statistical point of view, from a clinical point of view, the recently defined optimal single age cutoffs of 50 years for PTC and 40 years for FTC might be preferable. [ABSTRACT FROM AUTHOR]