Differences attributed to patient age and conditioning. Cumulative incidence of IPS among allogeneic HSCT recipients stratified by patient age and conditioning regimen. Cumulative incidence rates of IPS at 120 days after conventional conditioning were 11% and 5.7% for patients older than 40 years (solid line; n = 481) or aged 40 years or younger (broken line; n = 436), respectively (P = .005). Cumulative incidence rate of IPS after nonmyeloablative conditioning was 2.0% for patients older than 40 years (dotted line; n = 152).