A Retrospective Study to Determine If Early Platelet Recovery Correlates with Improved Prognosis in Acute Myeloid Leukemia
Authors: Parekh Deevyashali , Batayneh Osama , Bassir Ali , Olojakpoke Eloho , Sandhu Michael , Bou Zerdan Maroun , Vishwakarma Unnati , Gentile Teresa 
Published: December 2024

Introduction:
Prognostication in Acute Myeloid Leukemia (AML) is based on pre-treatment variables such as cell counts at diagnosis and risk stratification. However, recent studies have shown that an early platelet recovery may correlate with improved disease prognosis. Robust data to this effect is currently lacking and clear cut-offs for ‘early platelet recovery’ are not universally defined. We investigated a cohort of AML patients at our institution to determine if early platelet recovery did correlate with better prognosis.
Methods:
A retrospective analysis was performed on a cohort of AML patients treated at Upstate Medical University between January 2010 to June 2024. The subjects were at least 18 years of age or older and had a confirmed diagnosis of AML. Patients who did not receive any treatment or were diagnosed with other secondary subtypes of AML were excluded. Overall survival was measured from the day of initiation of induction treatment to date of death or last follow up. SPSS was used for data analysis, overall survival was measured using Kaplan Meier curves, significance measured using log rank test. Days to platelet recovery was measured from the initiation of induction chemotherapy to 3 consecutive days of platelet count &gt; 20 x 10^9/L. The 50th percentile for platelet recovery was 23.11 days hence this was taken as a cut-off for platelet recovery. Early platelet recovery was defined as recovery between 1-23 days, the comparison group was platelet recovery after 24 or more days or no platelet recovery.
Result:
The overall cohort included 183 patients. The mean age was 63.3 years (Range 21 to 96 years). 51.4% (n=94) were male. 77 patients achieved ‘early platelet recovery’. The comparison group had 106 patients. 28 out of 77 patients (36.4%) in the early platelet recovery group were deceased at the time the data was censored while 65 of 106 (61.3%) in the comparison group were deceased. The early platelets recovery group correlated to a better overall survival (p=&lt;0.001). The mean overall survival (OS) was 2045 days (95% CI 1477 - 2613) for the early platelet recovery group and 1088 days (95%CI 574 - 1602) in the late platelet recovery or no recovery comparison group.
Further subgroup analysis was done for induction with intensive chemotherapy and non-intensive chemotherapy.
131 patients were induced with ‘intensive’ chemotherapy. The early platelet recovery group correlated to a better overall survival (p=0.002) in patients induced with intensive chemotherapy. The mean overall survival (OS) was 2374 days (95% CI 1698 - 3049) for the early platelet recovery group and 1302 days (95%CI 665 - 1940) in the late platelet recovery or no recovery comparison group.
52 patients were induced with ‘non intensive’ chemotherapy. The early platelet recovery group correlated to a better overall survival (p=0.004) in patients induced with non intensive chemotherapy. The mean overall survival (OS) was 729 days (95% CI 477 - 980) for the early platelet recovery group and 271 days (95%CI 150 - 393) in the late platelet recovery or no recovery comparison group.
Conclusion
In the patient cohort with confirmed AML treated at our institution, early platelet recovery, measured as recovery in 23 days or fewer, correlated with an improved overall survival. This correlation was statistically significant even within the subgroups of induction with intensive chemotherapy and induction with non-intensive chemotherapy.