Stem cell transplantation in patients with chronic myelogenous leukemia: when should it be used?

Is survival in myeloid malignancies really improving? A retrospective 15-year population-based study

Myeloid malignancies (MMs) are heterogeneous groups of diseases which present different prognoses. Using data from the population-based Girona Cancer Registry, we estimated the relative survival (RS) rates and relative excess risk of death among patients with MMs in the province of Girona between 1994 and 2008. The 5-year RS rate was 49.7%, ranging from 20.2% for acute myeloid leukemia (AML) to 75.3% for myeloproliferative neoplasms (MPN). Marked differences in RS were observed when the age of patients was considered: an increase in RS was mainly found in younger patients with myelodysplastic syndromes and MPN. Furthermore, cases of chronic myeloid leukemia treated with imatinib had a significantly better outcome compared with those that were untreated. Despite the slight improvement in the survival rate of younger patients with AML, RS remained stable for 15 years, as no significant improvements were made in the management of the disease during that period.

Hematologic abnormalities following renal transplantation

Recipients of renal allografts are surviving longer and, consequently, may experience a variety of complications related not only to the transplanted kidney, but also to the hematopoietic system. Common hematologic complications in the renal transplant patient include abnormalities of one cell line, such as post-transplantation erythrocytosis or anemia, that are often treatable with simple measures. Conversely, pathologies involving the leukocyte and platelet population often exist in the context of pancytopenia, which may be a manifestation of systemic infection (e.g., cytomegalovirus, human herpesvirus 8) or malignancy (post-transplantation lymphoproliferative disorders). Uncommon, but life-threatening, processes complicating renal transplantation include hepatosplenic gammadelta T-cell lymphoma and viral-induced hemophagocytic syndrome, both of which are associated with severe pancytopenia and, often, death. Since this patient population is often managed in a multidisciplinary fashion by nephrologists, infection specialists, transplant surgeons, hematologists, and internal medicine physicians, a succinct review of this topic is warranted.

The role of blood services and regulatory bodies in stem cell transplantation

Advances in stem cell research over the past few decades have coincided with large increases in haemopoietic stem cell transplantation (HSCT) using either bone marrow, peripheral blood or cord blood-derived stem cells. Alongside this growth has come an increase in the role played by regulatory bodies, both governmental and professional, to ensure that those undertaking such procedures do so in a manner so as to minimize the risk to patients. Interestingly, government legislation encompasses not only cellular therapies, but also the use of tissues and organs, as many of the processes and procurement procedures involved are similar. In this review, we analyse the trends in HSCT, describe the development and impact of legislation within Europe on this practice and outline the vital role played by the UK blood services in providing robust and high-quality HSCT services.

Early allogeneic stem cell transplantation for chronic myelogenous leukemia in the imatinib era: A preliminary assessment

We have examined the role of early allogeneic hematopoietic stem cell transplantation in patients with chronic phase chronic myelogenous leukemia (CML) who enter a complete cytogenetic remission with imatinib mesylate. Three kinds of data were used to examine the effect of the outcome of current BCR-ABL inhibitor treatment compared to early allogeneic stem cell transplantation: (1) the life expectancy of the general population of the United States as a function of age, (2) the life expectancy of CML patients as a function of the age of patients treated with imatinib mesylate (imatinib) who achieve a complete cytogenetic remission, and (3) the life expectancy of patients with CML treated with matched-related or matched-unrelated stem cell transplantation as a function of age, derived from data provided by the Center for International Blood and Marrow Transplant Research (CIBMTR). We also considered separately the transplant results of the Fred Hutchinson Cancer Research Center (FHCRC), which are substantially better than the "average" outcome from the CIBMTR. We have calculated the projected life expectancy from the age at which patients with CML enter complete cytogenetic remission with imatinib and that of those who receive allogeneic stem cell transplantation. The outcome with imatinib therapy of newly diagnosed patients with CML has been documented for only 4 and 1/2 years, whereas transplant data were available for up to 25 years. Thus, in order to compare life expectancy and 10-year survival probability, it was necessary to extrapolate the imatinib data. A basis for extrapolation is offered and conservative estimates have been used for comparison. Our best estimate is that patients receiving imatinib who have a complete cytogenetic remission have a higher projected probability of 10-year survival than patients who are transplanted, based on results provided by the CIBMTR, and have about the same probability compared to the data from the Fred Hutchinson Cancer Center for patients in the 30- to 60-year-old range. The mathematical approach used here permits reexamining the analysis using future data on BCR-ABL inhibitor therapy or allogeneic stem cell transplantation therapy or both.