Deciding to Use Stem Cell Transplantation for Leukemia, Lymphoma, or Myeloma Two central questions should be answered when considering a transplant for a patient in remission: Does the current evidence indicate that stem cell transplantation will be more likely to cure the disease than other forms of therapy? Is there a compatible donor available as a source of stem cells? Other important factors that influence the decision include the patient’s age, the specific disease being treated, biologic features at the time of diagnosis that indicate a poor prognosis, and the presence of com- plicating medical conditions (see Figure 3). The age of the patient is a compelling factor in the decision to do a trans- plant. About three-quarters of individuals who develop leukemia, lym- phoma, or myeloma are over 50 years of age. Patients over that age are less likely to have a favorable outcome after transplantation. Indeed, the results of transplantation are best in children and become less favorable with each advancing decade. Older individuals are: 1) more susceptible to graft versus host disease ; 2) more likely to have complicat- ing medical problems; and 3) more likely to have a decreased tolerance for the accumulated effects of the prior intensive chemotherapy and the conditioning treatments required for transplantation. These are generaliza- tions and allogeneic transplantation can be used in older individuals when judgment favors that decision. Moreover, new techniques that require less harsh conditioning therapy are being explored for certain types of leukemia and lymphoma.