Trend in Survival in Patients Undergoing Allogeneic Stem Cell Transplantation: An Institutional Experience

Introduction: Allogeneic hematopoietic stem cell transplantation (allo-SCT) is a potentially curative treatment for many hematological malignancies and disorders. However, this potential is often impeded by several factors including relapse of the underlying disease, graft-vs-host disease (GVHD) and infectious complications. Specifically, acute GVHD continues to be a major factor in the morbidity and mortality of patients. Hence, the practice of allo-SCT is continuously evolving to mitigate these factors. In particular, advances in the conditioning regimens, GVHD prophylaxis, infectious disease monitoring and prophylaxis and supportive care not only have resulted in improved outcomes, but also have expanded potential indications for allo-HSCT. Therefore, we conducted a retrospective analysis on patients who underwent allo-SCT at The Ohio State University from 1986-2018 to better understand how survival has changed longitudinally in accordance with these therapeutic advancements. Method: We analyzed data from 1943 consecutive patients who received an allo-SCT. Patients were divided into seven groups based on the year of transplant: groups (gp) 1: 1984-1988, 2: 1989-1993, 3: 1994-1998, 4: 1999-2003, 5: 2004-2008, 6: 2009-2013, and 7: 2014-2018. The primary endpoints were overall survival (OS) and progression free survival (PFS), and log-rank test was used to compare across transplant years. The Kaplan-Meier method was used to estimate OS and PFS. The secondary endpoints were the cumulative incidences of grade II-IV and grade III-IV acute GVHD (aGVHD), chronic GVHD (cGVHD), and non-relapse mortality (NRM). Cumulative incidence rates were estimated and compared using Gray's test accounting for competing risks. Results: Across the years (1984-2018), the median age was 50.0 (range: 18-76) with 59.6% of the patients being male. Acute myeloid leukemia accounted for 36.3% of transplants, followed by non-Hodgkin lymphoma (14.2%), acute lymphoid leukemia (11.8%), chronic myeloid leukemia (10.1%), and myelodysplastic syndrome (10.0%). Fifty-five percent of patients received myeloablative conditioning. Across the groups, statistically significant improvements in PFS and OS were observed (p