Use of absolute lymphocyte counts to predict response to chemotherapy and survival in diffuse large B-cell lymphoma

Abstract

8082 Background: Absolute lymphocyte counts (ALCs) at diagnosis has been shown to be an independent prognostic factor in patients with follicular lymphoma (FL) although the precise mechanism was not fully elucidated. The current study evaluated the impact of Absolute lymphocyte counts (ALCs) at diagnosis in patients with diffuse large B-cell lymphoma (DLBCL) on the response to chemotherapy and survival. Methods: The treatment outcomes of the patients receiving CHOP (n=101) or R-CHOP chemotherapy (n=122) were compared according to ALCs at diagnosis (<1.0 vs. = 1.0×109/L). Results: Forty-two patients (19%) had a lower ALC count at diagnosis (CHOP, 23 [23%]; R-CHOP, 19 [16%]). The lower ALCs showed a good correlation with IPI (p<0.001), performance (p<0.001), LDH (p<0.001), stage (p=0.004), extranodal involvement (p=0.011), but not with age or sex. A significant difference of response rate was noted according to ALCs in favor of a higher ALCs (CR: 80% vs. 60%, p=0.005; ORR: 93% vs. 78%, p=0.003). In addition, event-free survival (EFS) was worse in a lower ALC group than higher ALC group: median duration of EFS, 1,773 days vs. 326 days (p<0.001). The OS was also in favor of a higher ALC group: median duration of OS, 3,000 days vs. 695 days (p<0.001). In multivariate analysis, ALC at diagnosis was an independent predictive factor for CR (HR 2.717, p=0.009) and prognostic factor for EFS (HR 2.148, p=0.004) or OS (HR 2.863, p=0.002). Conclusion: The ALCs at diagnosis appears to predict the survival of DLBCL patients. Our findings suggested that the ALCs at diagnosis may reflect host's immune status against DLBCL, implying that immune system of host will play a critical role on survival of DLBCL patients. No significant financial relationships to disclose.