Comparative efficacy and prognostic analysis of non-intensive chemotherapy in symptomatic versus asymptomatic newly diagnosed Acute Myeloid Leukemia

Abstract Background: Acute myeloid leukemia (AML) is a malignant hematologic tumor originating from hematopoietic stem/progenitor cells in the bone marrow and is the most common type of leukemia in adults. Common clinical manifestations include anemia, bleeding, infections, hepatosplenomegaly, lymphadenopathy, bone pain, and more. However, some patients show no obvious clinical symptoms at the time of AML diagnosis and are identified solely through abnormal findings in routine blood tests during physical examinations. Currently, there is no relevant research on whether there are differences in treatment efficacy and prognosis between symptomatic-onset and asymptomatic AML patients. Aims: This study aims to compare treatment efficacy and long-term prognosis between symptomatic-onset AML patients versus asymptomatic AML patients detected through physical examination, all receiving non-intensive chemotherapy. Furthermore, it seeks to identify prognostic factors influencing outcomes in asymptomatic AML groups. Methods: This was a retrospective, single-center study for asymptomatic/symptomatic newly diagnosed AML patients who received non-intensive chemotherapy treatment in Qilu Hospital of Shandong University from January 2018 to December 2023. Data were analyzed using SPSS 25.0 and GraphPad Prism 10.4.1. The median overall survival (OS) was estimated using the Kaplan-Meier method. Results: A retrospective cohort of 91 patients with newly diagnosed AML was enrolled in this study. In the baseline data, a statistically significant difference was observed between the asymptomatic and symptomatic groups in WBC count and ANC (p<0.001 and p=0.04, respectively). Furthermore, significant differences were also found in the proportion of blasts in peripheral blood and bone marrow (p<0.001 and p=0.014, respectively).Patients in the symptomatic group were more likely to have leukocytosis and blasts. All patients in both cohorts received non-intensive induction chemotherapy regimens due to advanced age and/or high-risk features at diagnosis, including severe granulocytopenia. Using the ELN 2022 criteria for risk stratification, these patients were stratified into intermediate-risk, high-risk, lower-risk (including low- and intermediate-risk) and higher-risk (comprising high- and intermediate-risk). Following one cycle of low-intensity induction therapy, no significant differences in complete remission (CR) rate, minimal residual disease (MRD) negativity rate, duration of neutropenia(days), or length of hospital duration(days) were observed between the symptomatic and asymptomatic groups among these risk-stratified patients. However, regardless of risk stratification, the asymptomatic group exhibited a lower rate of upper respiratory infections and longer overall survival (OS)(p<0.01). In the asymptomatic cohort, univariate Cox regression analysis evaluated the following covariates: sex, age, neutrophil count, monocyte count, hemoglobin level, platelet count, peripheral blast percentage, bone marrow blast percentage, length of hospitalization(days), duration of neutropenia (days), first complete response (CR1) status, MRD1 status, ELN 2022 risk classification, and upper respiratory tract infection incidence. Variables demonstrating statistical significance at p<0.1 were selected for multivariate analysis. The subsequent multivariate Cox model identified two independent prognostic factors for survival: increasing age (HR 1.06 [95% CI 1.02–1.11]; p=0.007) and achievement of CR1 (HR 0.27 [95% CI 0.08–0.95]; p=0.04). Summary/Conclusion: The analysis above demonstrates significant differences between asymptomatic and symptomatic AML in peripheral white blood cell counts and blast percentages (both peripheral blood and bone marrow). Although no statistically significant differences were observed between the two groups in hospitalization duration, neutropenia duration, CR rates, or MRD negativity rates, the asymptomatic subgroup exhibited superior survival outcomes and lower incidence of adverse events. These findings underscore the critical importance of timely diagnosis and early intervention for individuals with potential AML detected through abnormal routine blood tests during physical examinations.