Improved overall survival for pediatric patients undergoing allogeneic hematopoietic stem cell transplantation - A comparison of the last two decades

Abstract

Pediatric protocols for allogeneic hematopoietic SCT have been altered during the last two decades. To compare the outcomes in children (<18 yr old), who underwent SCT at our center during 1992-2002 (P1) and 2003-2013 (P2). We retrospectively analyzed 188 patients in P1 and 201 patients in P2. The most significant protocol changes during P2 compared with P1 were a decrease in MAC protocols, particularly those containing TBI, an increase in RIC protocols, and altered GvHD prophylaxis. In addition, P2 had more patients with nonmalignant diagnoses (p = 0.002), more mismatched (MM) donors (p = 0.01), and more umbilical CB grafts (p = 0.03). Mesenchymal or DSCs were used for severe acute GvHD during P2. Three-yr OS in P1 was 58%, and in P2, it was 78% (p < 0.001). Improved OS was seen in both malignant disorders (51% vs. 68%; p = 0.05) and nonmalignant disorders (77% vs. 87%; p = 0.04). Multivariate analysis showed that SCT during P2 was associated with reduced mortality (HR = 0.57; p = 0.005), reduced TRM (HR = 0.57; p = 0.03), unchanged relapse rate, similar rate of GF, less chronic GvHD (HR = 0.49; p = 0.01), and more acute GvHD (HR = 1.77, p = 0.007). During recent years, OS has improved at our center, possibly reflecting the introduction of less toxic conditioning regimens and a number of other methodological developments in SCT.

Keywords: allogeneic stem cell transplantation; pediatric hematopoietic stem cell; survival.