Effects of aGVHD and cGVHD on Survival Rate in Patients with Acute Myeloid Leukemia after Allogeneic Stem Cell Transplantation

Background: Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) is a curative treatment option for many patients with Acute Myeloid Leukemia (AML); however, it can lead to complications of Graft-Versus-Host-Disease (GVHD) which can affect the quality of life and overall survival. The aim of this study was to assess the effects of both acute and chronic GVHD on survival rate in patients with AML who received HSCT. Subjects and Methods: In a longitudinal study, 587 patients with AML who underwent bone marrow transplantation in Tehran-Iran between1991 and 2011 were recruited. All patient records were analyzed for the occurrence of adverse events including acute and chronic GVHD and leukemia relapse. Data were analyzed using Log-rank, Kaplan-Meier, Univariate and Multivariate Cox Regression models. Results: The five-year overall survival (OS) was found to be 71.9% (95% CI: 67.40-76.41). Also there was a significant relationship between cGVHD and OS (P=0.001, HR = 0.476, 95%). Hazard of death in these patients was less than those who did not experience an occurrence of cGVHD and aGVHD (HR= 0.629, P= 0.078). A significant relationship between cGVHD and relapse was observed (P< 0.001) indicating that patients who developed cGVHD experienced a better survival rate. A significant relationship was also found between overall survival and aGVHD grade (P< 0.001). Hazard of death (HD) for cGVHD and relapse variables were estimated to be 0.554 and 3.869. Discussion: This study is one of the largest studies (regarding the number of participants) done to date in the Middle East with quite a long duration (20 years). cGVHD appears to have a positive influence on survival rate in patients with AML who received HSCT. It is recommended that further studies investigate the underlying reason or mechanisms behind this.