Hematopoietic cell transplantation (HCT) for acute lymphoblastic leukemia (ALL): 25-year experience at the University of Minnesota

Abstract

7001 Background: HCT is frequently used for management of ALL. Methods: We reviewed the records of 623 consecutive patients (63% male, median age 13 years) treated with myeloablative TBI-containing conditioning and either autologous or allogeneic transplantation between 1980 and 2005 at the University of Minnesota. Donor types were autologous (34%), related (45%), unrelated (16%) or cord (11%). Disease status at transplant was CR1 (24%), CR2 (50%), CR3 (18%) and relapse (8%). Univariate and multivariate analyses were performed for clinical endpoints including overall survival (OS), progression free survival (PFS), relapse, treatment-related mortality (TRM), and Grades II-IV acute and chronic graft versus host disease (GVHD). Results: Median follow-up among survivors was 8.3 years (1.0–22.9). The estimated incidence of acute GVHD was 42% and chronic GVHD was 16%. At 5 years, OS, PFS, and relapse were estimated at 29%, 26%, and 43% respectively. 5-year OS for each group: autologous (17%, 12–22%), related (35%, 29–41%), matched unrelated (42%, 29–55%), mismatched unrelated (21%, 11–33%), and cord blood (46%, 33–59%). TRM at 2 years was 28%. Multivariate analysis for OS, PFS, relapse and TRM for donor type is shown ( Table ). Acute GVHD was more frequent with unrelated donors (p<0.01) but similar for related donors and cords. Presence of acute GVHD led to improved PFS (RR 0.6, 0.4–0.7, p<0.01) and decreased relapse (RR 0.5, 0.3–0.8, p<0.01) at 1 year. 5-year OS improved significantly from 1980–1984 (28%, 20–37%) to 2000–2005 (45%, 33–56%), p < 0.01. Conclusions: Allogeneic HCT results in a durable PFS, although TRM is increased with unrelated mismatched donors. As expected, autologous HCT results in increased relapse rates. Despite significant mismatch, umbilical cord HCT led to similar OS, PFS, relapse, TRM and chronic GVHD compared to related donor HCT. Development of acute GVHD decreases relapse, resulting in improved PFS. No significant financial relationships to disclose. [Table: see text]