Juvenile myelomonocytic leukemia natural history

Prognosis
Prognosis refers to how well a patient is expected to respond to treatment based on their individual characteristics at time of diagnosis. In JMML, three characteristic areas have been identified as significant in the prognosis of patients:

Without treatment, the survival of children with JMML is approximately 5%. Only Hematopoietic Stem Cell Transplantation (HSCT), commonly referred to as a bone marrow or (umbilical) cord blood transplant, has been shown to be successful in curing a child of JMML. With HSCT, recent research studies have found the survival rate to be approximately 50%. Relapse is a significant risk after HSCT for children with JMML. It is the greatest cause of death in JMML children who have had stem cell transplants. Relapse rate has been recorded as high as 50%. Many children have been brought into remission after a second stem cell transplant.

Relapse
After bone marrow transplant, the relapse rate for children with JMML may be as high as 50%. Relapse often occurs within a few months after transplant and the risk of relapse drops considerably at the one-year point after transplant. A significant number of JMML patients do achieve complete remission and long-term cure after a second bone marrow transplant, so this additional therapy should always be considered for children who relapse.