Long Term Outcomes Of Allogeneic Stem Cell Transplantation For Chronic Lymphocytic Leukemia

Allogeneic Stem Cell Transplantation (Al-SCT) remains an option for patients with advanced Chronic Lymphocytic Leukemia (CLL) with high risk features. We performed a retrospective analysis of our patients with CLL/Pro-lymphocytic leukemia (PLL) who underwent Al-SCT at our center between August 1989 and February 2009. The objective of this study is to evaluate the overall survival (OS), relapse free survival (RFS), acute and chronic graft versus host disease (aGVHD, cGVHD). We also compared the intensity of conditioning regimens (conventional: CIC Vs reduced: RIC), donor type, (matched sibling: MSD vs matched unrelated: MUD), graft source (bone marrow: BM vs peripheral blood: PB) and their impact on OS, RFS, aGVHD and cGVHD. There are 59 patients available for review. Patients characteristics are listed in table 1. There were a variety of conditioning regimens; for the CIC, 36 pts. received Busulfan based regimens and 10 pts. Total Body Irradiation based regimens, for the RIC 13 pts. received different fludarabine based regimens. Donor types were 48 MSD and 11 MUD. Source was BM in 27 and PB in 32 pts. Most (43/59 pts) received CyA-MTX as the GvHD prophylaxis but 12 and 4 pts. received Mycophenolate and Campath with CyA respectively. The median follow up is 45 months (7-237). The median survival time is 115 months with a 5 year survival probability of 57% (95% CI: 0.43-0.68). OS was not statistically significantly different when comparing type of conditioning or graft source, however a significant improvement in OS with MSD type over MUD, (P value=0.0007). The 3-year RFS is 48% (95% CI: 0.35-0.60) with no statistically significant difference according to regimen intensity and graft source, with a significant superior outcome for MSD Vs MUD (P value=0.002). Grade 2-4 aGvHD was seen in 40 cases. The cumulative rates of aGvHD 2-4 are not different between the conditioning, donor type and graft source. Forty-one cases (68%) experienced cGvHD (18% limited,50% extensive) with no difference according to regimen intensity and donor type, although a significantly increased incidence in the PB group (P value=0.03). Causes of death include infection (40%), GVHD (33%), relapse (18%) and VOD (9%). Acceptable survival post Al-SCT is possible in CLL although TRM is significant. This retrospective analysis demonstrates inferior survival for MUD recipients and similar outcomes when comparing RIC and CIC regimens.Table 1Patients characteristicsPts studied , n.59Diagnosis : CLL / PLL54 / 5Mean age (range), y46 (27-67)Gender (F /M), n.19 / 40Number of prior regimens, mean (range)4 (1-9)Prior Purine analogue84 %Prior Rituximab11 % Open table in a new tab