Evaluation to Prognostic Staging System of Multiple Myeloma in Novel Agent Era

Abstract Purpose This study was to evaluate existing staging system of multiple myeloma (MM) in the real world. Methods We retrospectively analyzed 886 newly diagnosed MM from two institutions. Results The overall survival (OS) of eligible patients was 61.0 months. R-ISS held a larger receiver operating characteristic curve (ROC) area (0.603) than that of ISS (0.573) and DS staging system (0.567). In the group of immunomodulatory agents-based regimens, the median OS was 92.0 months in R-ISS I, 63.0 months in R-ISS II and 18.0 months in R-ISS III (p<0.0001). In the group of proteasome inhibitors-based regimens, the median OS was 102.0 months in R-ISS I, 63.0 months in R-ISS II and 22.0 months in R-ISS III (p<0.0001). In different subgroups grouped according to Age, HGB, CREA and Ca, R-ISS also had a good stratification effect. Patients in R-ISS II were further analyzed, which accounted for 69.9% of all R-ISS patients. Using univariable and multivariable Cox analysis, Age>65 years (p=0.001), HGB<100g/L (p<0.001), elevated LDH (p=0.001) and Ca (p=0.010) were independent factors indicating worse prognosis for R-ISS II. Conclusion R-ISS remains a valuable staging system in the real world of new drug era. But patients classified in R-ISS II still have large heterogeneity.