Investigators from multiple institutions conducted a retrospective study to assess the rate of late mortality in children after autologous blood or marrow transplantation (autoBMT). Study participants were patients <22 years old who survived at least 2 years after autoBMT performed at City of Hope or the University of Minnesota between 1980 and 2010. Clinical data, including demographics and primary diagnosis, were obtained from institutional databases. Various vital statistics databases, including the National Death Index Plus, were reviewed to identify participants who died or were still alive as of December 31, 2016. For patients who had died, the investigators classified the cause of death as related to the primary disease, subsequent neoplasm, infection, or other. Kaplan-Meier techniques were used to evaluate the overall survival rates. The standardized mortality ratio (SMR, the ratio of observed to expected deaths) was calculated using death rates in the general US population among the same age group as that of the study cohort. Cox regression analyses were used to identify risk factors for late mortality; multiple confounding variables were included in the regression models.
Data were analyzed in 345 patients who survived >2 years after autoBMT. The median age of study participants at the time of autoBMT was 16 years, and the most common primary diagnoses were Hodgkin lymphoma (26% of patients), neuroblastoma (23%), acute myeloid leukemia (13%), acute lymphoblastic leukemia (13%), and non-Hodgkin lymphoma (9%). After a median follow-up of 14.2 years, there were 103 deaths among the cohort for a late mortality rate of 29.9%. The survival rates at 5, 10, and 15 years after autoBMT were 81.2%, 73.8%, and 70.3%. Among those who died, 50.0% of deaths were related to the primary diagnosis (ie, relapse related), 21.4% were due to subsequent neoplasms, and 18.4% were from infections. Compared to the general US population of the same age, the SMR among those who survived >2 years after autoBMT was 21.8 (95% CI, 17.9–26.3). Compared to that in patients receiving autoBMT prior to 1990, the risk of death was significantly lower in those who received autoBMT between 1990 and 1999 (hazard ratio [HR], 0.47; 95% CI, 0.26–0.86) and in those treated between 2000 and 2010 (HR, 0.33; 95% CI, 0.15–0.73). Female patients were also at a significantly increased risk of late mortality compared to male patients (HR, 1.82; 95% CI, 1.19–2.78).
The authors conclude that youth receiving autoBMT are at increased risk of late mortality compared to the general population, but late mortality rates have decreased since 1980.
Dr Hogan has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
Autologous hematopoietic cell transplantation involves rein-fusing patient-derived progenitor cells from blood or marrow...