High-dose BEAM chemotherapy with autologous haemopoietic stem cell transplantation for Hodgkin's disease is unlikely to be associated with a major increased risk of secondary MDS/AML

Hodgkin's disease is curable in the majority of patients, although a proportion of patients are resistant to or relapse after initial therapy. High-dose therapy with autologous stem cell support has become the standard salvage therapy for patients failing chemotherapy, but there have been reports of a high incidence of myelodysplasia/acute myeloid leukaemia (MDS/AML) following such treatment Patients who receive such therapy form a selected group, however, who have already been subjected to other leukaemogenic factors, such as treatment with alkylating agents. In order to ascertain the true risk of MDS/AML, comparison must be made with other patients subjected to the same risks but not undergoing transplantation. We report a retrospective comparative study of 4576 patients with Hodgkin's disease from the BNLI and UCLH Hodgkin's databases, which includes 595 patients who have received a transplant. Statistical analysis including Cox's proportional hazards multivariate regression model with time-dependent covariates was employed. This analysis reveals that the risk of developing MDS/AML was dominated by three factors, namely quantity of prior therapy (relative risk [RR] 2.01, 95% confidence intervals [CI] 1.49-2.71, for each treatment block, P < 0.0001) and whether the patient had been exposed to MOPP (RR 3.61, 95% CI 1.64-7.95, P = 0.0009) or lomustine chemotherapy (RR 4.53, 95% CI 1,96-10,44, P = 0.001). Following adjustment for these factors in the multivariate model the relative risk associated with transplantation was 1.83 (95% CI 0.66-5.11, P = 0.25). This study provides no evidence of a significantly increased risk of MDS/AML associated with BEAM therapy and autologous transplantation in Hodgkin's disease. Concern over MDS/AML should not mitigate against the timely use of this treatment modality. (C) 1999 Cancer Research Campaign.