Clinical value of new staging systems for multiple myeloma

We wanted to investigate the validity of the recently introduced Southwest Oncology Group (SWOG) staging system and the International Staging System (ISS) by comparing both systems with the widely accepted Durie/Salmon (DS) system for multiple myeloma patients. Between 1992 and 2005, 85 multiple myeloma patients (men: women 41:44, median age: 63 years (range: 36~87)) with available baseline values of albumin and beta(2)-microglobulin were enrolled. The clinical and laboratory data were retrospectively obtained. According to the ISS, 11 patients were stage I (12.9%), 30 patients stage II (35.3%) and 44 patients stage III (51.8%). The median survivals of the ISS stages I, II and III were 78.6 months, 31.8 months and 15.1 months, respectively (p=0.015). The DS staging system was not able to predict the survival. For the SWOG staging system, 14 patients were stage I (16.4%), 27 patients stage II (31.8%), 27 patients stage III (31.8%) and 17 patients were stage IV (20.0%). The median survivals of the SWOG staging system stage I, II, III and IV were 78.6 months, 31.8 months, 11.6 months and 24.8 months, respectively (p=0.0075). The ISS staging system showed better reliability, simplicity and predictability for survival than the DS and SWOG staging systems for multiple myeloma patients.