Background: Definite prognostic clinical factors of benefit for decitabine-based induction chemotherapy in elderly patients newly diagnosed with acute myeloid leukaemia (AML) are not identified. This study was designed to explore the potential biomarker, especially regeneration of haematopoiesis, of treatment response and survival in elderly patients with newly diagnosed AML.
Method: We analysed the clinical data of 117 elderly AML patients who were treated with a decitabine dose of 15 mg/m2 for 5 days, granulocyte colony-stimulating factor of 300 μg/d for priming, plus cytarabine 10 mg/m2 q12h for 7 days and aclarubicin 10 mg/d for 4 days (D-CAG).
Results: After initial induction chemotherapy, the overall response rate and complete remission (CR) were 71.8% and 58.1%, respectively. Patients responding to the D-CAG regimen achieved higher platelet counts on day 14 after initial treatment (p < 0.001). Median counts were 59.5 × 109/L in the CR group, 37 × 109/L in the partial remission group and 28 × 109/L in the non-responsive group. We then classified patients into those who achieved platelet counts≥60 × 109/L or 100 × 109/L on day 14 after D-CAG vs. those who did not. Platelet counts≥60 × 109/L or 100 × 109/L on day 14 were significantly associated with superior CR, overall survival and disease-free survival (80.9% vs. 45.3% p < 0.001,16.5 vs. 9.1 months p = 0.009 and 16.3 vs. 7.4 months p = 0.024; 85.2% vs. 50% p = 0.001, 31 vs. 10.1 months p = 0.003 and 16.9 vs. 8.9 months p = 0.006). Multivariate analysis confirmed that poor cytogenetics (p = 0.010) and FLT3-ITD mutation (p = 0.007) were identified as independent factors of OS, but not platelet count (p = 0.091). However, platelet count≥100 × 109/L on day 14 was an independent prognostic factor of CR and DFS.
Conclusion: Platelet count recovery on day 14 after D-CAG induction chemotherapy is associated with response.
Trial registration: D-CAG regimen was registered on ChicTR with number 11001700 .
Keywords: Acute myeloid leukaemia; Decitabine; Elderly; Platelet recovery; Prognostic indicator.