Feasibility of Autologous Peripheral Blood Stem Cell Transplantation in Elderly Patients with Acute Myeloid Leukemia.

Autologous stem cell transplantation (ASCT) is commonly used as postremission therapy for young adult patients with acute myeloid leukemia (AML). However, AML predominantly affects elderly people, more than half of the cases being currently diagnosed in patients over 60 years. Either registry data or single institutions studies have clearly shown that ASCT is feasible in older individuals with encouraging results in terms of transplant related mortality and disease free survival. Nonetheless, most of these studies referred to highly selected patients considered as eligible to ASCT after complete remission (CR) achievement and successful bone marrow harvest or peripheral blood stem cell (PBSC) mobilization. Till now, few studies have specifically addressed the issue of feasibility of APBSCT in consecutive series of elderly patients with AML. In this study we evaluated the feasibility of ASCT from a series of 155 consecutive AML patients aged over 60 years, observed from 2001 to 2005 at our Institution and programmed to receive ASCT by using PBSCs in the case of eligibility to intensive induction therapy followed by CR achievement. The median age was 72 years (range: 61–94). Overall, 90 out of 155 patients (58%) were judged as eligible to receive aggressive chemotherapy aimed at CR achievement. Reasons of exclusion were age by itself (≥ 80 years) in 25 patients (16%) and severe concomitant disease in 40 (26%). Among 90 patients who received intensive induction therapy (fludarabine + cytarabine in 79 patients and idarubicin + cytarabine in 11 patients), 45 (50%) obtained CR. Of these, 36 (80% of the remitters) received the programmed consolidation course and 32 (89% of consolidated patients) were monitorized for CD34 positive (CD34+) cell mobilization. Main reasons for the exclusion from consolidation therapy were: early relapse (n= 3) and toxicity due to induction therapy (n=6), while 4 patients died from sepsis during the severe neutropenic phase after consolidation. A successful collection of CD34+ cells (>2x10E6/kg) was registered in 25 out of 32 patients (78% of monitorized patients). Patients not mobilizing received one further course of consolidation therapy. Finally, 20 patients were actually given ASCT and there was no transplant related mortality. Reasons for not autografting 5 mobilizing patients were relapse pre-ASCT (n=2), toxicity (n=2: left foot ischemic gangrene due to uncontrolled diabetes and cardiac failure, respectively), refusal of the patient (n=1). The median survival was 27 months for autografted patients and 9 months for those not autografted (p:0.01). Overall, 20 out of 90 patients accrued into intensive chemotherapy (22%) and 20 out of the whole elderly AML patient population observed in the period of the study (13%) underwent ASCT. We conclude that APBSCT can result in an improvement of therapeutic results in AML of the elderly, but it is feasible in a small minority of patients. In our experience, only 22% of patients enrolled into trials based on aggressive chemotherapy and 13% of the whole patient population did actually receive the procedure.