Objective: To explore the clinical characteristics of multiple myeloma (MM) patients with overall survival (OS) less than 24 months so as to stratify high-risk population.
Methods: A total of 177 newly diagnosed MM inpatients were recruited from July 2008 to July 2012. Clinical parameters at diagnosis of international staging system (ISS), lactic dehydrogenase (LDH), serum calcium, extramedullary involvement and amyloidosis were collected and cytogenetic abnormalities were detected by fluorescence in situ hybridization (FISH). Response and death were recorded as endpoints. Otherwise the follow-up period was over 24 months.
Results: And 73 patients dying within 24 months were classified into high-risk group while another 104 survivors for over 24 months into control group. Age and gender at baseline were comparable. However, OS of high-risk group was only 8 months while it was not attained during a median follow up of 38 months in control group (P < 0.001). The most common cause of death was progressive disease in both groups. The pre-treatment percentages of the following parameters were significantly higher in high-risk group, including ISS stage III (76.71% (56/73) vs 50.00% (52/104), P = 0.002), renal dysfunction (47.95% (35/73) vs 31.73% (33/104), P = 0.029), elevated LDH (20.55% (15/73) vs 7.69% (8/104), P = 0.015) and plasma cell leukemia (PCL, 5.48% (4/73) vs 0 (0/104), P = 0.016). Conversely, extramedullary involvement, plasmacytoma, amyloidosis and hypercalcemia were similar. Despite comparable chemotherapeutic regimens, the rate of deep response, including complete response (CR) and very good partial response (VGPR), was significant lower in high-risk group than that in control group (12.33% (9/73) vs 53.85% (56/104), P < 0.001). Overall response rates (ORR, i.e. CR+VGPR+ partial response (PR)) were markedly different (38.36% (28/73) vs 86.54% (90/104), P < 0.001). Univariate analysis of cytogenetic abnormalities indicated a higher proportion of 1q21 amplification in high-risk group (35.62% (26/73) vs 25.15% (22/104), P = 0.033). Multivariate Logistic regression revealed that ISS, LDH and primary response worse than PR independently affected early death (P = 0.046, 0.005, < 0.001).
Conclusions: MM patients with OS less than 24 months have distinct clinical characteristics. And aggressive regimens are needed to improve the outcomes of high-risk population.