Impact Of Peripheral Blood Absolute Lymphocyte Count On Survival In Adult Patients With Acute Lymphoblastic Leukemia

Objective:To study the impact of peripheral blood absolute lymphocyte count(ALC)on survival in adult patients with acute lymphoblastic leukemia(ALL)at multiple time points during the induction chemotherapy.Methods:We conducted a retrospective review of 122 adult patients with ALL between January 2001 and December 2017 in the Second Hospital of Shanxi Medical University.To analyze the impact of ALC at different time points(ALC-1,ALC-8,ALC-15,ALC-22,ALC-28)and ALC ratios for RFS and OS of adult ALL.Results:1.To Select the critical value by ROC curve.The area under the curve of ALC was less than 0.5 at ALC of initial diagnosis,ALC-1,ALC-8,ALC-15,and ALC-8/ALC-1,there was no meaningful critical point,no follow-up comparison.2.The study cohort was divided into two groups according ALC-22 values(<580 cells/μL and ≥580 cells/μL).There was no significant difference in RFS and OS.The study cohort was divided into two groups according ALC-28 values(<675 cells/μL and ≥675 cells/μL).The median RFS(8 months VS 12 months,P=0.001),median OS(16 months VS 23 months,P=0.010),the difference was statistically significant.3.ALC-15/ALC-1 with 28% cut-off was relatively insignificant.ALC-22/ALC-1 with 18.5% cut-off was only meaningful for RFS.ALC-28/ALC-1 was bordered by 43%.The RFS and OS in the low ratio group were shorter than the high ratio group,which was significant(P=0.008,P=0.008).4.ALC-15/ALC-8 was divided into two groups with 101% cut-off and ALC-22/ALC-8 with 78% cut-off.There was no statistically significant difference between RFS and OS.ALC-28/ALC-8 was compared with 86% cut-off.Longer RFS and OS in higher ALC-28/ALC-8 group(P=0.022,P=0.013).5.CR rate of four weeks was higher in the high ALC-28 group.Bone marrow remission rate of two weeks,CR rate of four weeks and normal karyotype were higher in the high ALC-28/ALC-1 group,but WBC of ininitial diagnosis was lower.In the high ALC-28/ALC-8 group,there were more females,B-ALL,and standard-risk patients.Bone marrow remission of two weeks,no leukemia in peripheral blood,and CR of four weeks were high.6.Bone marrow leukemia cell ratio of two weeks,CR rate of four weeks,with or without extramedullary infiltration,ALC-28,ALC-28/ALC-1,ALC-28/ALC-8 and ALC-22/ALC-1 were RFS-related factors.Bone marrow leukemia cells of two weeks ≥ 5%,extramedullary infiltration,and low ALC-28 were independent risk factors for RFS.Bone marrow leukemia cell ratio of two weeks,age,CR rate of four weeks,ALC-28,ALC-28/ALC-1 and ALC-28/ALC-8 were OS related factors.Among them,old age,low ALC-28,and low ALC-28/ALC-1 were independent risk factors of OS.7.ALC-28 of Low-risk(LR),intermediate-risk(IR),and high-risk(HR)were(809.27±472.68),(919.11±632.43)and(649.31±400.27)cells/μL.The ALC-28 value was smaller in the HR group,but not statistically significant(P=0.204).ALC-28/ALC-1 was(49.73±48.56),(37.08±32.65)and(26.47±72.42)%,ALC-28/ALC-8 was(162.25±217.39),(157.73±166.55)and(64.32±53.20)%,both values decreased with increasing risk,which was statistically significant.The proportions of high ALC-28,high ALC-28/ALC-1,and high ALC-28/ALC-8 in the LR and IR groups was large,and the proportion in the HR was low,with statistical significance.Conclusion:1.ALC-28,ALC-28/ALC-1,and ALC-28/ALC-8 were associated with RFS and OS of adult ALL.ALC-22/ALC-1 was significant in RFS.The higher the value,the longer the survival time.2.In the analysis of clinical characteristics of patients,high ALC and high ratio groups tend to have better influencing factors.3.Many factors were associated with RFS and OS.Bone marrow leukemia cells of two weeks ≥ 5%,extramedullary infiltration,and low ALC-28 were independent risk factors for RFS.Older age,lower ALC-28 and lower ALC-28/ALC-1 were independent risk factors for OS.4.Patients with high ALC and their ratios were large proportion in LR and IR,which represent a lower risk and may become a new indicator for evaluating risk stratification.