Clinical value of absolute lymphocyte counts before bortezomib-dexamethasone therapy in relapsed multiple myeloma patients.

A high absolute lymphocyte count (ALC) at diagnosis is known as a surrogate marker of favorable prognosis in newly diagnosed multiple myeloma (MM). Recent studies showed tumor sensitization and enhanced cytotoxicity of bortezomib. We hypothesized that a high ALC before bortezomib treatment would contribute to tumor sensitization and activated cytotoxicity of bortezomib in relapsed MM. Ninety-seven relapsed MM patients who underwent bortezomib-dexamethasone (Vel-Dex) therapy were analyzed. Median follow-up duration was 21 months and median age was 61 years. Complete response (CR) and very good partial response (VGPR) after 2 cycles of Vel-Dex therapy were higher in the high-ALC group (>or=1.1 x 10(9)/l) (CR + VGPR 50.0% in the high-ALC group vs. 10.4% in the low-ALC group, p = 0.001), and stable disease (SD) rate was lower in the high-ALC group (SD 11.8% in the high-ALC group vs. 44.8% in the low-ALC group, p < 0.001). In the univariate analysis, the low-ALC group before therapy was associated with shorter progression-free survival (PFS) [hazard ratio (HR), 2.780; 95% confidence interval (95% CI) 1.703-4.536, p < 0.001]. Multivariate analysis revealed that a low ALC represented an independent predictive factor for PFS (HR 1.937, 95% CI 1.168-3.212, p = 0.010). A low ALC just before Vel-Dex therapy was associated with a poor prognosis in relapsed MM. Copyright 2010 S. Karger AG, Basel.