Peripheral blood lymphocyte/monocyte ratio at the time of first relapse predicts outcome for patients with relapsed or primary refractory diffuse large B-cell lymphoma

BACKGROUND: Despite the use of modern immunochemotherapy regimens, a significant proportion of diffuse large B-cell lymphoma (DLBCL) patients will relapse. We proposed absolute lymphocyte count/absolute monocyte count ratio (ALC/AMC ratio) as a new prognostic factor in relapsed or primary refractory DLBCL. METHODS: We retrospectively analyzed 163 patients who have been diagnosed with relapsed or primary refractory DLBCL. The overall survival (OS) and progression-free survival (PFS) were measured from the time of first relapse. The Cox proportional hazards model was used to evaluate ALC/AMC ratio as prognostic factors for OS and PFS. RESULTS: On univariate and multivariate analysis performed with factors included in the saaIPI, early relapse, prior exposure to rituximab and autologous stem-cell transplantation (ASCT), the ALC/AMC ratio at the time of first relapse remained an independent predictor of PFS and OS (PFS: P < 0.001; OS: P < 0.001). Patients with lower ALC/AMC ratio (<2.0) had lower overall response rate, 1-year PFS and 2-year OS rate compared with those with higher ALC/AMC ratio (≥2.0). Moreover, the ALC/AMC ratio can provide additional prognostic information when superimposed on the saaIPI. CONCLUSIONS: Lower ALC/AMC ratio at the time of first relapse is a adverse prognostic factor for OS and PFS in relapsed or primary refractory DLBCL, and leads to the identification of high-risk patients otherwise classified as low/intermediate risk by the saaIPI alone.