[Prognostic Factors and Predictive Value of MRD before Consolidation Therapy in Middle-risk Newly Diagnosed Young and Middle-aged Patients with AML]

Abstract

Objective: To explore the prognostic factors of young and middle-aged patients with acute myeloid leukemia (AML) and the predictive value of minimal residual disease (MRD) before consolidation therapy.

Methods: The clinical data of 262 middle-risk young and middle-aged patients with AML treated in our hospital from January 2010 to December 2018 were selected retrospectively. All the patients were reached morphological leukemia-free state (MLFS) after induction chemotherapy, the overall and subgroup clinical data of the selected patients were analyzed. Cox regression model was used to evaluate the independent prognostic factors of middle-risk newly diagnosed young and middle-aged patients.

Results: Among the patients less than 40 years old treated by consolidation therapy with PR-CT and allo-HSCT regimens, the 5-year cumulative leukemia-free survival(LFS) rates were 40.92% and 63.51%（P=0.01）respectively, while those over 40 years old were 23.61% and 49.14%（P=0.00）, respectively. The 5-year cumulative LFS rates of the patients treated by chemotherapy and achieved early remission and late remission were 63.51% and 41.33% （P=0.01）, respectively. The 5-year cumulative overall survival(OS) rates of the patients treated by PR-CT and allo-HSCT regimens were 23.65% and 69.32% (P=0.00), respectively, and the 5-year cumulative LFS rates were 26.44% and 52.30% (P=0.01). Among the patients treated by PR-CT consolidation treatment, the MRD-negative and MRD-positive cases were 74 and 60 cases, respectively. The 5-year cumulative incidence of relapse rate in the MRD-negative subgroup was significantly lower than those in the MRD-positive subgroup (P<0.05), the 5-year LFS rate and OS rate of the patients in MRD-negative subgroup were significantly higher than those in MRD-positive subgroup (P<0.05). For the patients treated by allo-HSCT consolidation treatment, the MRD-negative and MRD-positive cases were 66 and 62 cases, respectively. The 5-year cumulative incidence of relapse rate of the patients in MRD-negative subgroup was significantly lower than those in MRD-positive subgroup（P<0.05）, and the 5-year LFS and OS rates of the patients in MRD-negative subgroup were significantly higher than those in MRD-positive subgroup (P<0.05). The univariate analysis results showed that age, chromosome karyotype, MRD status after reaching MLFS, and consolidation treatment regime were all related to the prognosis of patients (P<0.05). The multivariate analysis results showed that age, MRD status after reaching MLFS, and consolidation therapy were the independent factors affecting the cumulative OS rate of the patients (P<0.05). Chromosome karyotype was an independent factor affecting the cumulative LFS rate of the patients (P<0.05). MRD status and consolidation treatment plan after reaching MLFS were the independent factors affecting the cumulative recurrence rate of the patients (P<0.05).

Conclusion: The OS rate of middle-risk young and middle-aged patients with newly diagnosed AML is independently related to age, MRD status after MLFS and consolidation therapy, while chromosome karyotype is independently related to cumulative LFS, and allo-HSCT consolidation therapy is recommended for middle-risk young and middle-aged AML patients after induction chemotherapy for MLFS, especially for those less than 40 years old and MRD positive before consolidation therapy.