The use of receiver operating characteristic (ROC) curves analysis in the evaluation of the diagnostic efficiency of serum pseudouridine as a tumor marker

The biochemical parameters used in this study were: (1) serum pseudouridine, expressed as nmols/mL; (2) pseudouridine index, expressed as mol to mol ratio of serum pseudouridine versus serum creatinine concentration. The receiver operating characteristic (ROC) analysis has been used to exemplify the selection of discriminant values or "cut-off points" to maximize the diagnostic utility of a biochemical tumor marker, serum pseudouridine. This marker has been used in a variety of group population samples, i.e., normal subjects, subjects affected by several nonneoplastic diseases, subjects with neoplastic disorders in less advanced or more advanced stages, and finally in a sample population of patients affected by lymphomas and leukemias of different types. An analysis of the relative ROC curves allowed the selection of cut-off values that maximize the diagnostic efficiency or, alternatively, the diagnostic sensitivity or the diagnostic specificity for pseudouridine parameters, and has allowed the comparison of the two tests to answer the same clinical question.