Radiation-free regimens result in similar outcomes of allogeneic hematopoietic progenitor cell transplantation in patients aged ≥50 years compared to younger adults with low-risk disease

Age greater than or equal to50 years has been reported to be an adverse risk factor for allogeneic BMT, and consequently many of these patients are either not transplanted or treated on nonmyeloablative protocols. To study if older patients perform poorly relative to younger adults following myeloablative allogeneic transplants, we compared the outcomes of consecutive adults aged greater than or equal to50 years (n = 51) to those <50 years (n = 262) who received BU, CY+/- etoposide and allogeneic transplantation for AML, CML, MDS and NHL from 1984 to 2000. Median ages were 53 (range 50-66) and 35 (range 18-49) years for older and younger patients, respectively. Patients were low-risk if they had AML in CR1, CML in first chronic phase, refractory anemia, or NHL in remission or sensitive relapse at the time of transplantation. All others were high-risk. In patients with low-risk disease, there was no significant difference in overall survival (OS) between older and younger adults (P=0.64), while older patients tended to have a shorter OS among high-risk patients (P = 0.06). The 3-year OS was 53% (95% CI, 29-77%) compared to 60% (95% CI, 50-69%) for older and younger patients with low-risk disease, respectively. The corresponding 3-year OS were 27% (95% CI, 11-43%) and 37% (95% CI, 25-45%) for high-risk patients. In low-risk patients, the incidence of acute and chronic graft-versus-host disease, and treatment-related mortality were similar in older and younger patients, while older patients experienced more treatment-related deaths by day 100. On multivariable analysis, age greater than or equal to50 years was a significant adverse factor only when high-risk patients were considered. We conclude that when radiation-free conditioning is used, age greater than or equal to50 years is not a significant adverse risk factor for allogeneic BMT in patients with low-risk disease, and that such patients should not be excluded from conventional myeloablative approaches until the efficacy of nonmyeloablative transplantation is better established.