Survival of patients with chronic myelogenous leukaemia relapsing after bone marrow transplantation: comparison with patients receiving conventional chemotherapy

The occurrence of Philadelphia chromosome (Ph) negative leukemia after hematopoietic stem cell transplantation for Ph positive chronic myeloid leukemia: implications for disease monitoring and treatment

Chronic myeloid leukemia (CML) is a clonal neoplastic disorder, characterized by t(9;22)(q34;q11) that results in the formation of the Philadelphia chromosome (Ph) and the BCR/ABL fusion gene. Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for CML. Much of its therapeutic efficacy is attributed to a graft-versus-leukemia (GVL) effect exerted by donor-derived lymphoid cells against the Ph positive (Ph+) clone. Post-HSCT monitoring by cytogenetic and molecular detection of the Ph+ clone is necessary, so that pre-emptive immunologic or pharmacologic treatment may be administered at an early stage of relapse. However, under rare circumstances a second Ph negative (Ph-) leukemia may evolve post-HSCT. The pathogenetic possibilities included leukemia arising from donor-derived hematopoietic stem cells (HSCs), or transformation of residual recipient-derived Ph- HSCs that have survived the conditioning chemotherapy and radiotherapy. Recipient-derived Ph- leukemia may be related to genetic alterations that precede the onset of CML, or myelotoxic effects of the HSCT conditioning regimen. The diagnosis of Ph- relapses requires detailed investigations by conventional karyotyping, fluorescence in-situ hybridization (FISH), and molecular analysis; as well as chimerism studies that help to document the donor or recipient origin of the leukemia. Although uncommonly reported in the past, Ph- relapses may in fact be more frequent if leukemic relapses post-HSCT are more thoroughly evaluated with these investigations. The recognition of Ph- relapses are important in several ways. Ph- relapses cannot be identified by monitoring investigations targeting the Ph+ clone, so that the early detection of Ph- leukemia is usually not possible. Furthermore, Ph- relapses will not respond to therapeutic strategies effective against the Ph+ CML clone.

Factors associated with survival in patients with progressive disease following autologous transplant for lymphoma

Our objectives were to assess survival and predictors for survival among lymphoma patients whose disease had progressed after autologous bone marrow (ABMT) or stem cell transplantation (ASCT). Patients transplanted at Hadassah University Hospital between October 1983 and February 1999 were included. We compared survival of patients with Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) after relapse or progression. Predictors for survival were assessed in a multivariate model. Of 88 transplanted patients with HD and 152 with NHL, relapse/progression occurred in 27 (31%) and 75 (49%), respectively. Median survival postrelapse was 25 months for HD and 7.5 months for NHL (P=0.12). Seven relapsed patients with HD (26%) and 10 (13%) with NHL survived >4 years. In NHL, longer postrelapse survival was associated with indolent histologies (P=0.007). On multivariate analysis, factors associated with survival included attainment of remission postrelapse (for both diseases), use of prophylactic immunotherapy (for HD), LDH level and time from transplant to relapse (for NHL). The short-term prognosis for patients with disease progression postautologous transplant may be somewhat better for HD compared to NHL. Long-term survival is poor in both diseases. However, the survival times in the current study are twice as long as those previously reported. Treatment regimens with the potential for achieving remission may have an impact on survival.