Prognostic value of immunophenotyping in multiple myeloma:: A study by the PETHEMA/GEM cooperative study groups on patients uniformly treated with high-dose therapy

Purpose To analyze the prognostic impact of immunophenotyping in patients with multiple myeloma ( MM). Patients and Methods We have prospectively analyzed the prognostic impact of antigenic markers, assessed by multiparametric flow cytometry, in a series of 685 newly diagnosed MM patients that were uniformly treated according to the GEM 2000 protocol. Results Our results show that expression of both CD19 and CD28 as well as the absence of CD117 were associated with a significantly shorter progression free-survival ( PFS) and overall survival ( OS). Interestingly, the CD28 expression correlated with t(14; 16) and del(17p), while CD117-negative patients were associated with t( 4; 14) and del( 13q). Simultaneous assessment of CD28 and CD117 antigens allowed stratification of patients with MM into three risk categories: poor risk ( CD28 positive CD117 negative), intermediate ( either both markers negative or both positive), and good risk ( CD28 negative CD117 positive), with PFS rates of 30, 37, and 45 months, respectively ( P =.01), and OS rates of 45, 68, and not reached, respectively ( P =.0001). Conclusion To the best of our knowledge, this is the first prospective analysis in which the prognostic impact of a relatively high number of antigenic markers has been simultaneously analyzed in a large series of uniformly treated patients, showing that the expression of several antigens ( particularly CD28 and CD117) on bone marrow plasma cells from patients with MM can help to identify patients at high risk of progression.