The loss or absence of minimal residual disease of <0·1% at any time after two cycles of consolidation chemotherapy in CBFB-MYH11-positive acute myeloid leukaemia indicates poor prognosis.

No consensus has been reached on the relationship between CBFB-MYH11 copies and prognosis. Of 1525 acute myeloid leukemia (AML) patients, 58 with CBFB-MYH11-positive AML (16/58 patients with c-kit mutation) were retrospectively analyzed with a median follow-up duration of 29.8 (range: 4.8-74.4) months. Of these, 25/58 (43.1%) patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT), 10 of whom had the c-kit mutation. Of the 33 patients who did not undergo allo-HSCT, recurrence in patients with CBFB-MYH11/ABL level >0.1% at any time after two consolidation cycles was significantly higher than in patients with CBFB-MYH11/ABL level <0.1% (61.9% vs. 0%, P = 0.001); further, the 3-year relapse-free survival (RFS; 31.4% vs. 100%, P = 0.004) and event-free survival (EFS; 33.1% vs. 100%, P = 0.004) were significantly decreased in patients with CBFB-MYH11/ABL level >0.1% at any time after two consolidation cycles. The 3-year RFS and EFS rates were lower in patients who did not receive allo-HSCT than in those who did (31.4% vs 84.6%, P = 0.000; 31.4% vs. 80.8%, P = 0.001). CBFB-MYH11-positive AML patients with CBFB-MYH11/ABL level >0.1% at any time after two cycles of consolidation had poor prognoses, and allo-HSCT could improve their survival.