Late Platelets Recovery after Autografting (ASCT) in Patients with Acute Myeloid Leukemia (AML) Is A Prognostically Favourable Factor for Long-Term Remission

Althought favourable results with ASCT in patients with AML in first CR have been reported, there are no definitive data indicating that this approach is superior to chemotherapy alone. We have recently reviewed our 23 years experience with ASCT in AML in Genoa. From January 1984 to December 2007, 79 patients in first CR, aged 18–65 years, who did not have a sibling donor, were autografted. These patients had been previously treated in induction with Ara-C 200 mg/m²/d × 7 days and DNR 50 mg/m²/d × 3 days. Soon after, they had received consolidation therapy with 4 courses of DAT therapy (DNR 50 mg/m²/d1, Ara-C 200 mg/m² c.i. day 2–5, thioguanine 80 mg/m² days 2–5). Fifty patients were autografted with bone marrow and 29 patients with peripheral blood stem cells. High-dose therapy consisted of Cyclophosphamide and single dose TBI (n=50) or high-dose busulfan and cyclophosphamide (n=29). At a median of 11 years, 15 patients (19%) are still alive and well. At that time genetic aberrations combined or not with cytogenetics were not available; therefore we have retrospectively analyzed the patients according to age, sex, WBC count, time to CR and conditioning regimen. None of these factors was predictive for long-term remission. On the contrary, we found that late platelets recovery was predictive. The median time to recover platelets > 50 × 10⁹/L was 72 days (45–115 days) in long-term remission patients versus ≤ 30 days in the other patients who relapsed. During the presentation details of this retrospective study will be discussed. In conclusion, the late recovery of platelets after autografting is in our experience the most predictive factor for long-term remission duration in autografted AML patients.