Purging of bone marrow in autologous bone marrow transplantation for non-Hodgkin's lymphoma: a case-matched comparison with unpurged cases by the European Blood and Marrow Transplant Lymphoma Registry.

Abstract

The use of in vitro purging of bone marrow in autologous bone marrow transplantation (ABMT) for non-Hodgkin's lymphoma (NHL) has been a controversial issue; its benefit is as yet unproven. Its effect on the clinical outcome of ABMT in these patients is still unclear. We look at this issue using data from the European Blood and Marrow Transplant (EBMT) Lymphoma Registry. Seventeen hundred twenty-six patients with NHL have been reported to the EBMT registry, of whom 270 had bone marrow purged at transplant. Two hundred twenty-four of these patients were compared with a case-matched group of 224 unpurged patients who had undergone the same procedure. The case matching was made following selection of the main prognostic factors for progression-free survival (PFS) by multivariate analysis. Response, complications, and outcome in ABMT were analyzed. Time to hematologic engraftment, response to ABMT, and number of procedure-related deaths were similar in purged and unpurged patients. The overall survival (OS) rate was 54% at 5 years in purged patients and 48.3% in unpurged patients (P = .1813). The PFS rate was 44.3% and 44.6%, respectively (P = .1961). Patterns of relapse, including bone marrow relapse, were similar in both groups. Patients with low-grade lymphoma did not have a significantly improved PFS if the bone marrow was purged (P = .1757); however, they did have a significantly improved OS (P = .00184). This increased OS was found to be associated with non-totalbody irradiation (TBI) conditioning and also with the purged patients undergoing transplantation at large transplant centers (P = .0016). Purging of bone marrow in ABMT for NHL does not affect the rate of hematologic engraftment or risk of procedure-related death (PRD). There is no significant difference in PFS for patients whose bone marrow is purged as compared with unpurged.