Role of autotransplantation in the treatment of acute promyelocytic leukemia patients in remission: Fukuoka BMT Group observations and a literature review.

ABSTRACT

We retrospectively analyzed the outcomes of 26 patients with acute promyelocytic leukemia (APL) in the first CR (CR1) or second CR (CR2), who underwent autologous PBSCT (auto-PBSCT) between 1992 and 2008. All patients received all-trans retinoic acid-based induction therapy. After two courses of consolidation chemotherapy, upfront auto-PBSCT was performed in 20 patients in the CR1. Five patients had a high WBC count of more than 10 × 10(9)/L (high risk), while 15 patients had a count of less than 10 × 10(9)/L (low risk) at initial presentation. In addition, six patients, who were considered as low-risk patients at presentation, had a relapse after three cycles of consolidation and 2 years of maintenance therapy, but gained the molecular remission after re-induction and consolidation, and underwent auto-PBSCT in the CR2. In 26 recipients, engraftment was rapid and no TRM was documented. All 20 patients autotransplanted in CR1 were still in CR at a median of 133 months (73-193 months), and six patients who underwent auto-PBSCT in CR2 were also still in CR at a median of 41 months (2-187 months) without maintenance therapy. PML/RARα chimeric mRNA was undetectable in PBSC or BM samples examined before auto-PBSCT. Despite a small number of cases studied, our retrospective observations suggest that auto-PBSCT may be an effective treatment option to continue durable CR in the treatment of high-risk APL. We review previous reports and discuss the role of autotransplantation in the treatment of APL patients in CR.