Long-term survival can be achieved in a significant fraction of older patients with core-binding factor acute myeloid leukemia treated with intensive chemotherapy

Abstract

Acute myeloid leukemia (AML) is mainly a disease of the elderly: however, knowledge about the outcomes of treatment of core-binding factor (CBF) AML in an older population is limited. We retrospectively collected data on 229 patients with CBF-AML followed long-term in the last two decades. The 5-year overall survival was 44.2% (95% confidence interval [95% CI]: 39.9-47.5) and the 5-year event-free survival was 32.9% (95% CI: 25.5-40.1). In a subgroup of patients ≥70 years old who completed intensive therapy (induction + ≥3 courses of consolidation including autologous stem cell transplantation: 10 patients) the median event-free survival was 11.8 months (95% CI: 9.4-15.2) and overall survival was 40.0% (95% CI: 36.4- 44.1) at 5 years. In univariate analysis, age ≥70 years (hazard ratio [HR]=1.78, 95% CI: 1.15-2.54, P=0.008), failure to achieve remission following induction (HR=8.96, 95% CI: 5.5-13.8; P<0.0001), no consolidation therapy (HR=0.75, 95% CI: 0.47-1.84, P=0.04) and fewer than three cycles of consolidation (HR=1.48, 95% CI: 0.75-3.2; P=0.0004) predicted poorer event-free survival. Our study shows that intensive therapy, in selected older CBF-AML patients, leads to longer survival. Achieving a complete remission seems to be the most important first step and at least three cycles of consolidation, an important second one. The analysis suggests that these patients should not be excluded from studies with intensive therapies.

Figure 1.

Flow-chart of the disposition of the patients analyzed in the study. CHT: chemotherapy; HSCT: hematopoietic stem cell transplantation; AutoHSCT: autologous HSCT; AlloHSCT: allogeneic HSCT.

Figure 2.

Overall survival and event-free survival according to age and core-binding factor translocation. (A) Overall survival of the whole study population. (B) Overall and event-free survival of patients divided according to age: <70 years versus ≥70 years. (C) Overall and event-free survival of patients divided according to core-binding factor translocation: t(8;21) versus inv(16).

Figure 3.

Event-free survival according to frontline treatment and age. (A) Event-free survival of patients divided according to frontline treatment. (B) Event-free survival of patients divided according to both frontline treatment and age (<70 years vs. ≥70 years). autoHSCT: autologous hematopoietic stem cell transplantation.