Background and objectives: The risk of relapse after autologous bone marrow transplantation (ASCT) is high and is related to the type of malignancy and phase of the disease. The outcome for the patient who relapses after an autologous transplant is poor. Some of these patients achieve a remission with conventional chemotherapy, but it is usually short-lasting. Most of them succumb to the original disease. One further therapeutic possibility is an allogeneic transplant which would confer the potential advantage of a graft-versus-leukemia effect in addition to the lack of tumor contamination of the graft and to a high-dose intensity conditioning regimen.
Design and methods: We have studied the outcome of 31 patients with hematologic malignancies who underwent an allogeneic hematopoietic stem cell transplant (HSCT) after failing an autologous transplant because of relapse (n=29) or persistent aplasia (n=2). The median age at allograft was 36 years (18-55) and the interval from autograft to allograft was 21 months (3-141). The source of stem-cells was unmanipulated bone marrow (n=26) or growth-factor-mobilized peripheral blood (n=5). The donor was an HLA-identical sibling (n=7), or an alternative donor (n=24) (family mismatched n=11, or matched unrelated n=13). The conditioning regimen was cyclophosphamide and thiotepa (n=22), or cyclophosphamide and total body irradiation (n=9) Graft-versus-host disease (GvHD) prophylaxis consisted of cyclosporine (CyA) + methotrexate (MTX).
Results: Acute GvHD was scored as 0-I, II, or III-IV in 39%, 48%, and 13% of the patients, respectively. Sixteen patients died of transplant-related complications and one of progressive disease. With a median follow-up of 220 days (9-2104) the actuarial 2-year transplant-related mortality (TRM) was 51%, the actuarial relapse risk 37%, the actuarial survival 46%. Fifteen patients (48%) are alive in complete remission, with a median follow-up of 32 months (range 2-71).
Interpretation and conclusions: These data suggest that patients relapsing after an autotransplant should be screened for potential related or unrelated donors: although TRM remains high there is a definite chance of long-term disease-free survival if these patients are allografted.