Risk factors that influence outcomes for acute leukemia patients with relapse after hematopoietic stem cell transplant.

This study aimed to investigate risk factors that influence the outcome of acute leukemia patients who experience relapse after hematopoietic stem cell transplant.

This study concluded that certain factors, such as older age and not acheiving remission after relapse treatment, are associated with worse survival outcomes.

A hematopoietic stem cell transplant (HSCT) is a common treatment option for patients with acute leukemia (AL). It involves taking stem cells from a matched donor and transferring them to the patient. Post-transplantation relapse can occur and AL can come back. Patients who relapse after HSCT have poor prognosis, and require further treatment. It is not known what risk factors influence the outcome for these patients.

This study involved 234 AL patients who underwent HSCT. Patients from this group who experienced a post-transplantation relapse received post-relapse treatment and were evaluated after 6 months. Remission status and survival were assessed. The risk factors influencing post-relapse overall survival (prOS, time from treatment until death from any cause), complete remission (CR, no sign of active disease) and non-relapse mortality (NRM, death not due to AL) were analyzed.

17.9% of all patients experienced post-transplantation relapse.  When these patients were treated, 25.6% had post-relapse remission (no evidence of cancer). The 6-month prOS rate was 20.9% and the NRM rate was 25.6%.

Older age and failure to experience remission after relapse treatment were associated with lower prOS.

Female sex, post transplantation extramedullary relapse (recurrence of AL in sites other than the bone marrow) and absence of post-relapse graft-versus-host-disease (GVHD is where the body attacks cells that have been transplanted) were associated with lower CR rate.

The presence of extramedullary relapse was associated with lower risk of NRM. Treatment of post-transplantation relapse with donor lymphocyte infusion (white blood cells are transferred to patient after HSCT) with or without chemotherapy and occurrence of post-relapse GVHD were associated with higher risk of NRM.

This study concluded that survival of AL patients who relapse after HSCT is poor, especially in elderly patients and those who do not have remission after relapse treatment. The authors suggest that research into new treatment options is needed, and that these risk factors can help to guide treatment.

The limitations to this study are that there was a short follow up period and small sample size.