Adult Type Chronic Myelomonocytic Leukemia is part of the spectrum of myelogenous leukemias that may have findings that simulate typical chronic myelogenous leukemia (CML) such as anemia, high white cell count and enlargement of the spleen but is often also calssified as a type of myelodysplasia. However, the cells do not contain the Ph chromosome, or BCR-ABL oncogene, that characterizes chronic myelogenous leukemia. The age and general health of the patient are factors when determining the intensity of CMML treatment. Cytarabine, either standard or low-dose, etoposide, hydroxyurea, and other approaches used for the low-blast count myelogenous leukemias have been tried with little success. Stem cell transplantation can be considered in younger patients (<50 years) with a matched donor. Median survival in CMML is about 20 months, with a range from about 10 to over 60 months.
The first MUD transplant in CMML was reported in 1986. Mulltiple series and cases were subsequently reproted as well as retrospective reviews but no prospective randomized studies have been done.Various chemotherapy regimens for CMML have been used with only modest success.
Bone marrow or stem cell transplantation appears to be the only current treatment that alters the natural history of CMML. In a review of 118 young MDS patients (median age 24, age range 0.3–53 years) who received allogeneic bone marrow transplants from matched unrelated donors, the actuarial probability of survival at 2 years for the 12 patients with CMML was 10%. Transplant-related mortality was influenced by the age of the patient (i.e., <18 years, 40%; 18–35 years, 61%; >35 years, 81%). This study included patients who received transplants as early as 1986, which may have influenced the patient survival data.[Level of evidence: 3iiiA] In a recent review of 50 allogeneic transplantations for CMML (i.e., median age 44, age range 19–61 years) from related (n = 43) or unrelated (n = 7) donors, the 5-year-estimated overall survival was 21%. The 5-year estimated probability of relapse was 49%. The data showed a trend for a lower relapse probability of acute graft versus host disease grade II through grade IV and for a higher relapse rate in patients with T cell-depleted grafts, suggesting a graft-versus-CMML effect. This latter series represents the largest cohort of patients with adult CMML and allogeneic stem cell transplantation to date.[Level of evidence: 3iiiA
The references article by Onida et al makes the recommendation that allogeneic stem cell transplantation in this disease should only be preformed in clinical trials.
Francesco Onida, Giovanni Barosi, Giuseppe Leone, Luca Malcovati, Enrica Morra, Valeria Santini, Giorgina Specchia, Sante Tura, Management Recommendations For Chronic Myelomonocytic Leukemia: Consensus Statements From The SIE, SIES, GITMO Groups
Haematologica September 2013 98: 1344-1352
Eric Padron, MD, Rami Komrokji, and Alan F. List, The Clinical Management of Chronic
Myelomonocytic Leukemia. MDClinical Advances in Hematology & Oncology Volume 12, Issue 3 March 2014
Kröger N, Zabelina T, Guardiola P, Runde V, Sierra J, Van Biezen A, Niederwieser D, Zander AR, De Witte T.Allogeneic stem cell transplantation of adult chronic myelomonocytic leukaemia. A report on behalf of the Chronic Leukaemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT).Br J Haematol. 2002 Jul;118(1):67-73.