Prognostic value of the revised international staging system for newly diagnosed multiple myeloma patients

Objective: To assess the prognostic value of revised international staging system (R-ISS) for multiple myeloma (MM) in real world. Methods: A total of 202 newly diagnosis symptomatic MM patients were enrolled from May 2010 to April 2015 and the clinical data were retrospectively analyzed. All the patients received at least four courses of bortezomib-based or thalidomide-based induction therapy. Results: With a median follow-up of 31 months, the cohort included 56 cases in R-ISSⅠ, 108 in R-ISS Ⅱ, and 38 in R-ISS Ⅲ, and the median OS was not reached/61/38 months, respectively (P=0.001). According to the ISS system, 62 patients were classified in ISS-Ⅰ, 70 in ISS-Ⅱ and 70 in ISS-Ⅲ, with the median OS was 58, 52 and 40 months, respectively (P=0.001). The relative risk (HR) of R-ISS stage Ⅲ vs Ⅰ, Ⅱ vs Ⅰ were 9.606 (P=0.008) and 4.038 (P=0.029). The HR of Ⅲ vs Ⅰ, Ⅱ vs Ⅰ of ISS system were 4.127 (P=0.070) and 2.877 (P=0.005). In the subgroup analysis, R-ISS predicted survival for patients who were not transplanted (P=0.003) , receiving bortezomib-based therapy (P=0.010) , and patients younger than 65 years (P=0.001). Conclusion: R-ISS system could better predict prognosis for OS in unselected nonclinical trial myeloma patients than ISS system, especially for the younger patients, patients with bortezomib-based therapy, and patients without transplantation.