Prognostic significance of apoptotic index in multiple myeloma patients treated by conventional therapy and novel agents,thalidomide and bortezomib

Objective: To assess the outcome of the measurement of apoptotic index in myeloma patients treated by conventional chemotherapy and novel drugs with biological mechanism of action, thalidomide and bortezomib. Patients and methods: In a cohort of 189 patients with newly diagnosed multiple myeloma from November 1997 through February 2008, we assessed the prognostic significance of plasma cell apoptotic index (PC‐AI) using annexin‐V. The whole group was subsequently divided according to treatment approach (conventional chemotherapy only vs. inclusion of novel drugs, thalidomide and bortezomib), and curves of overall survival were constructed. Results: In the whole group (n = 189), low levels of PC‐AI <4.5% significantly separated patients with unfavorable prognosis (median OS 16 vs. 38 months, P = 0.004). In patients treated with conventional chemotherapy only (n = 139) the results were similar (median OS 10 vs. 25 months, P = 0.02), and the apoptotic index maintained its significance even within the group of 50 patients treated also with novel drugs (median OS 30 vs. 54 months, P = 0.027). PC‐AI was found to be independent on both Durie‐Salmon staging system and the International Prognostic Index. Conclusion: Presented results suggest the use of apoptotic index by flow cytometry measurement as a fast and accessible method for prognostic stratification of myeloma patients in routine practice.