Myeloablative allografting for chronic lymphocytic leukemia: evidence for a potent graft-versus-leukemia effect...

Area of Science:

• Hematology
• Oncology
• Transplantation Medicine

Background:

• Chronic lymphocytic leukemia (CLL) is a mature B-cell malignancy.
• Allogeneic bone marrow transplantation (BMT) is a potential curative therapy for eligible CLL patients.
• Limited data exists on long-term outcomes of myeloablative allogeneic BMT in CLL.

Purpose of the Study:

• To evaluate the long-term efficacy and safety of myeloablative allogeneic BMT in patients with chronic lymphocytic leukemia (CLL).
• To assess the impact of donor type and graft-versus-host disease (GVHD) on survival and relapse rates.

Main Methods:

• Retrospective analysis of 30 CLL patients undergoing myeloablative allogeneic BMT between 1989 and 2001.
• Data collected on patient characteristics, preparative regimens, donor types, GVHD, and outcomes (survival, relapse, mortality).
• Statistical analysis including actuarial survival and cumulative incidence of NRM and relapse.

Main Results:

• 47% of patients (14/30) were alive at a median follow-up of 4.3 years, all in complete remission.
• 5-year event-free survival (EFS) was 39%, with overall survival (OS) of 48% for related donors and 20% for unrelated donors.
• Acute and chronic GVHD were associated with a decreased risk of relapse, suggesting a graft-versus-leukemia (GvL) effect.
• Unrelated donor BMT was associated with increased nonrelapse mortality (NRM) and decreased OS.

Conclusions:

• Allogeneic BMT can achieve long-term event-free survival in approximately 40% of CLL patients.
• A significant graft-versus-leukemia effect is observed, mediated by GVHD, which substantially reduces relapse risk.
• Unrelated donor transplantation carries higher risks of mortality and lower survival rates compared to related donor transplantation.