The Clinical Significance Of Platelet Count Trajectories After The First Cycle Of Induction Chemotherapy In AML Patients

BackgroundPlatelet counts varied over time after induction chemotherapy.We aimed to investigate the different trajectories of platelet counts after the first cycle of induction chemotherapy in patients newly diagnosed with acute myeloid leukemia.MethodsData of 149 newly diagnosed acute myelogenous leukemia patients(acute promyelocytic leukemia and secondary acute myelogenous leukemia were excluded)between May 1,2013 and May 1,2021 admitted in Qianfoshan Hospital of Shandong Province were evaluated retrospectively,and all patients were followed up until July 1,2021.The baseline characteristics,including age,gender,white blood cell count,hemoglobin,platelet counts,and bone marrow blasts at the time of diagnosis,were collected.Using group-based trajectory modeling method,we investigated the univariate trajectories of platelet counts.The characteristics across different platelet count groups were compared using statistical analysis.To study the association between diverse trajectories of platelet counts and overall survival,the Kaplan-Meier survival curve of each platelet trajectory group was plotted.The log-rank test was used to determine whether statistical differences exist in survival rate among platelet count trajectories.The Cox proportional hazard model was used to evaluate the association between the groups and overall survival.Results(1)In total,149 individuals were included in this study.We identified four distinct trajectories using a group-based trajectory model:low-stability group(n=27,18.12%),low-level decrease-medium elevation group(n=42,28.19%),low-level decrease-high elevation group(n=60,40.27%),and high-level decrease-medium elevation group(n=20,13.42%).(2)There were statistical significance in mortality rate per 1,000 person-days,overall survival time,hemoglobin,platelet count and complete remission of first induction chemotherapy among groups with different platelet trajectories.(3)In the Cox proportional hazard model adjusted for age and sex,compared with low-stability group,the platelet count trajectories of the low-level decrease-medium elevation group,low-level decrease-high elevation group and high-level decrease-medium elevation group were related to an decreased risk of mortality,and the corresponding hazard ratio(95%confidence interval)were 0.32(0.15-0.68),0.31(0.16-0.63)and 0.35(0.14-0.91).(4)After adjusting for age,sex,white blood cell count,hemoglobin and bone marrow blasts,both low-level decrease-medium elevation group(hazard ratio=0.34,95%confidence interval 0.15-0.79)and low-level decrease-high elevation group(hazard ratio=0.33,95%confidence interval 0.15-0.73)were associated with a decreased risk of death compared with low-stability group.(5)After adjusting for age,sex,white blood cell count,hemoglobin,bone marrow blasts and platelet counts,both low-level decrease-medium elevation group(hazard ratio=0.35,95%confidence interval 0.15-0.82)and low-level decrease-high elevation group(hazard ratio=0.32,95%confidence interval 0.14-0.72)were associated with a decreased risk of death compared with low-stability group.Conclusion(1)The dynamic trajectory of platelet counts after the first cycle of induction chemotherapy is a significant predictor of prognosis in patients with acute myeloid leukemia.(2)The low-stability group was an independent risk factor.(3)The low-level decrease-medium elevation and low-level decrease-high elevation groups were independent protective factors.