Prognostic Significance Of Platelet Count At Initial Diagnosis,after First Induction Therapy And Its Recovery Time In Children With Acute Myeloid Leukemia

Objective To analyse the prognostic significance of PLT count at initial diagnosis after first induction therapy and its recovery time in children with AML and explore easily available indicators for predicting the prognosis of children with AML.Methods Fifty-eight patients under the age of 18 with AML diagnosed by bone marrow cytology,flow cytology,immunology,cytogenetics,and molecular biology and treated with chemotherapy in the General Hospital of Ningxia Medical University from January 1,2000 to January 31,2017(except for acute early childhood Myeloid leukemia,M3)were studied.All patients were treated with standard induction therapy.The patients were subdivided into death group(44 cases)and survival group(14 cases)according to survival outcome,as well as non-relapsed group(13 cases)and relapsed group(45 cases).The impact of age,sex,WBC count,HGB,PLT count,PLT on the 28th day after the first induction therapy and the time after induction of PLT recovery to 110×10~9/L,risk stratification,the myeloproliferative level at complete response(CR),the status of CR after the first induction were analyzed,so as to look for clinical indicators that affect the prognosis,and determine whether PLT at different periods is of statistical significance for the prognosis.SPSS 22.0 software was used for statistical analysis,and Cox proportional hazards regression model was used to analyze the prognostic factors.Results1.Grouped by survival outcome,the comparison of the general clinical characteristics between the two groups showed statistical significance in age,PTL count at day 28 after the first induction therapy,and the time for PLT to recover to 110×10~9/L after induction(P=0.017,P=0.033,P=0.024,respectively).Univariate analysis showed statistical significance in age,PLT at initial diagnosis and PLT at day 28 after the first induction therapy(P=0.024,P=0.043,P=0.003,respectively).Multivariate analysis showed that age?14 years(HR=1.883),PLT(<50×10~9/L or>110×10~9/L)at initial diagnosis(HR=2.270)were risk factors while PLT(>110×10~9/L)was a protective factor for survival outcomes(HR=0.401)with statistical significance(P=0.042,P=0.018,P=0.004,respectively).2.Grouped by recurrence,the comparison of the general clinical characteristics between the two groups showed that the PLT level on day 28 after the first induction therapy in the relapsed group was significantly lower than that in the non-relapsed group(P=0.037).Univariate analysis showed significant differences in age,PLT at initial diagnosis,and PLT at day 28 after the first induction therapy(P=0.027,P=0.014,P=0.004,respectively).Multivariate analysis showed that age?14 years(HR=2.084),PLT at initial diagnosis(<50×10~9/L or>110×10~9/L)(HR=3.042)were risk factors for relapse while PLT(>110×10~9/L)was a protective factor against relapse(HR=0.393)with statistical significance(P=0.019,P=0.002,P=0.004,respectively).Patients with PLT at 50-110×10~9/L had longer disease free survival(DFS)than that with<50×10~9/L or>110×10~9/L at initial diagnosis(P=0.009).Patients with PLT>110×10~9/L had better DFS than those with?110×10~9/L at day 28 after the first induction(P=0.002).3.The time to PLT recover to 110×10~9/L after induction could not be used as a prognostic indicator,and multivariate analysis is needed in more patients.Conclusion1.AML patients with a PLT count of 50-110×10~9/L initial diagnosis had significantly longer OS and DFS,which could be used as independent influencing factors for good prognosis.2.AML patients with PLT count>110×10~9/L at day 28 after the first induction chemotherapy,which could be used as independent influencing factors for good prognosis.