Correlations Of The Percentage Of Peripheral Blood Blasts On Day7of Induction Chemotherapy With Therapeutic Efficacy In Patients With Acute Myeloid Leukemia

Objective: To discuss the correlation of the percentage of peripheralblood blasts on day7of induction chemotherapy predicts response to therapyand survival in AML patients, and further clarify it can judge individualsensitivity to chemotherapy.Methods: Seventy-three consecutive patients with de novo AML(excluding acute promyelocytic leukemia) were enrolled in this study. Thepatients were treated with DA/IA induction course. Flow cytometry wasperformed to identify cells with a leukemia-associated aberrantimmunophenotype in the initial bone marrow aspirate and in peripheral bloodon day7of induction therapy.Results: After a single DA/IA course,41patients achieved CR,11patients achieved PR, and21patients failed. The CR rate was56.16%(41/73),the overall response rate was71.23%(52/73). The follow-up time ranged from3to48months, the median follow-up time was18months,23patients had diedand24patient had relapsed. The mortality rate was31.51%, the relapsed ratewas32.88%. The median OS and RFS were14.5months (range,4-48) and8months (range,3-45), respectively. The peripheral blood blasts percentage onday7(D7PBBP) was significantly lower in the patients who achieved CR[0.025%(0.0%,12.47%)] than those did not [2.09%(0%,80.74%)]; u=-3.803,P <0.001). Spearman analysis showed that the D7PBPP was significantlycorrelated with CR after the first course (r=0.388, P <0.001). ROC curveanalyzed, at a cutoff value of0.945%(the AUC was0.755, P <0.001), the sensibility was66.7%, and specificity was77.5%. The D7PBBP was correlatedwith the bone marrow clearance on day14after induction chemotherapy (r=0.253, P=0.031). In addition, the D7PBBP was correlated with WBC (r=0.388,P <0.05) and bone marrow blast cell (r=0.279, P <0.05) before inductiontherapy, but it was irrelevant to cytogenetic risk groups (P=0.725), AML1/ETO(P>0.05)，gene mutation (P>0.05). In univariate analysis, ROC curve wasused to determine that the strongest univariate predictor to OS and RFS was0.43%, and AUC was0.796. Survivorship curve showed that OS and RFS weresignificant higher in patients with a D7PBBP <0.43%than in those with aD7PBBP≥0.43%(P=0.003and P=0.002). Multivarable analysis showed thatachieving CR after one induction course and the D7PBBP level were theindependent prognostic risk factors.Conclusions:1.The D7PBPP is significantly correlated with CR after the first course,the strongest cutoff is0.945%, and can predict the response to the inductiontherapy.2. The D7PBBP is correlated with WBC and bone marrow blast cellbefore induction therapy inAML patients.3. The D7PBBP is correlated with bone marrow residual intermittent14days.4. D7PBBP level may be the independent prognostic risk factors in acutemyeloid leukemia.