Interpreting data on transplant selection and outcome in adult acute lymphoblastic leukemia (ALL)

Until 10 to 15 years ago allogeneic transplants were performed in acute lymphoblastic leukemkia (ALL) mostly for advanced disease. They were rarely performed in first remission except for patients who were positive for the Philadelphia chromosome. Over the past decade, allogeneic transplants are being increasingly performed also for select patients in first remission, and the use of matched unrelated donors has vastly increased the availability of the donor pool for ALL patients. The data for reduced-intensity conditioning (RIC) transplants are at their infancy for ALL, but are likely to come into their own over the next decade, given the vast potential of offering this also to older patients or those with comorbidities. Despite the plethora of data, reports from various study groups differ in their enthusiasm for transplantation in many instances, and published data are often contradictory. Much of the data may have inherent selection biases and their interpretation may be confusing and difficult. The study conditions should be carefully described for physicians and patients to be able to adequately interpret the data.