Peripheral blood lymphocyte/monocyte ratio at diagnosis and survival in classical Hodgkin's lymphoma

Abstract

BACKGROUND: Lymphopenia and tumor-associated macrophages are negative prognostic factors for survival in classical Hodgkin's lymphoma. We, therefore, studied whether the peripheral blood absolute lymphocyte count/absolute monocyte count ratio at diagnosis affects survival in classical Hodgkin's lymphoma. DESIGN AND METHODS: We studied 476 consecutive patients with classical Hodgkin's lymphoma followed at the Mayo Clinic from 1974 to 2010. Receiver operating characteristic curves and area under the curve were used to determine cut-off values for the absolute lymphocyte count/absolute monocyte count ratio at diagnosis, while proportional hazards models were used to compare survival based on the absolute lymphocyte count/absolute monocyte count ratio at diagnosis. RESULTS: The median follow-up period was 5.6 years (range, 0.1-33.7 years). An absolute lymphocyte count/absolute monocyte count ratio at diagnosis of 1.1 or more was the best cut-off value for survival with an area under the curve of 0.91 (95% confidence interval, 0.86 to 0.96), a sensitivity of 90% (95% confidence interval, 85% to 96%) and specificity of 79% (95% confidence interval, 73% to 88%). Absolute lymphocyte count/absolute monocyte count ratio at diagnosis was an independent prognostic factor for overall survival (hazard ratio, 0.18; 95% confidence interval, 0.08 to 0.38, P<0.0001); lymphoma-specific survival (hazard ratio, 0.10; 95% confidence interval, 0.04 to 0.25, P<0.0001); progression-free survival (hazard ratio, 0.35; 95% confidence interval, 0.18 to 0.66, P<0.002) and time to progression (hazard ratio, 0.27; 95% confidence interval, 0.17 to 0.57, P<0.0006). CONCLUSIONS: The ratio of absolute lymphocyte count/absolute monocyte count at diagnosis is an independent prognostic factor for survival and provides a single biomarker to predict clinical outcomes in patients with classical Hodgkin's lymphoma.