Validation of the prognostic value of the Mayo MASS and R2-ISS staging systems in patients newly diagnosed with multiple myeloma: A single-center study

Abstract

Objective: To evaluate the prognostic value of Mayo MASS and R2-ISS staging systems in patients newly diagnosed with multiple myeloma (MM) . Methods: A total of 371 patients newly diagnosed with MM in Jiangsu Province Hospital were included in the study. Cytoplasmic light chain immunofluorescence with fluorescence in situ hybridization (cIg-FISH) was performed to detect cytogenetic abnormality. Clinical characteristics were combined to analyze the disease stage and evaluate the prognosis. Results: There were 37 (10.0%), 264 (71.0%), and 70 (18.8%) patients in R-ISS stage Ⅰ, Ⅱ, and Ⅲ, respectively. The median progression-free survival (PFS) times were 37, 25, and 14 months (P<0.001). The median overall survival (OS) times were not reached (NR), 66, and 30 months (P<0.001). There were 71 (19.1%), 140 (37.7%), and 160 (43.2%) patients in Mayo MASS stages Ⅰ, Ⅱ, and Ⅲ, and the median PFS times periods were 43, 27, and 19 months (P<0.001), and the median OS times were NR, NR, 35 months, respectively (P<0.001). There were, 23 (6.2%), 69 (18.6%), 222 (59.8%), and 57 (15.4%) patients in R2-ISS stages Ⅰ, Ⅱ, Ⅲ, and Ⅳ, respectively. The median PFS times were 47, 31, 25, and 15 months (P=0.001), and the median OS times were NR, NR, 49, and 55 months, respectively (P<0.001) . Conclusion: Based on the R-ISS staging system, Mayo MASS, and R2-ISS prognostic staging system incorporated 1q21+, which allows a better stratification. However, the proportion of stage Ⅲ patients in Mayo MASS and R2-ISS staging systems is relatively high, which is considered related to the high incidence of 1q21+ and ISS Ⅲ in the Chinese population.