A national study of allogeneic stem cell transplantation for adults with acute myeloid leukemia: Do gender and age above 70 years matter?

Abstract

e19020 Background: Allogeneic stem cell transplantation (alloSCT) is increasingly being offered to older patients with acute myeloid leukemia (AML) due to availability of reduced-intensity conditioning regimens and better supportive care. Though studies have shown improving alloSCT survival outcomes in older age groups, it is still not known if older age confers higher mortality and morbidity during transplant hospitalization. We queried a national inpatient database to evaluate in-hospital mortality and resource utilization during alloSCT for AML in patients >70 years compared to a younger age group. Methods: We conducted a retrospective study of alloSCT for AML patients ≥ 18 years using the 2018 National Inpatient Sample database. Hospitalizations were selected using International Classification of Disease, tenth revision (ICD-10) codes. Demographics, comorbidities, transplant, and outcome variables were compared between a reference age group (18-70 years) and a comparator group (> 70 years). Study outcomes were in-hospital mortality, length of stay (LOS) and transplant complications. Regression models were fit to assess the association between predictors and outcomes. Results: During the study period, 2610 alloSCT met the inclusion criteria. This cohort consisted of 50% males and 77% Caucasians. Only 7% of these alloSCT were performed for patients > 70 years. Patients >70 yrs had a lower proportion of females compared to the reference age group (32% versus 52%, p<0.01). There were no significant differences in racial distribution, Charlson comorbidity index or median income between the 2 age groups. In-hospital mortality rates for the reference age group versus >70 years were 3% and 5% respectively (p=0.35). In a multivariable model, we found no association between age >70 years and in-hospital transplant mortality. Acute graft versus host disease was more frequent among the reference age group (14% versus 2%, p=0.04), but there were no differences in LOS or rates of graft failure, respiratory failure, sepsis, and acute renal failure between the 2 groups. Conclusions: Despite similar in-hospital transplant outcomes as their younger counterparts, patients >70 years comprised only a small proportion of alloSCT performed for AML in our study. Females were more disproportionately affected by this age disparity. More studies are necessary to identify barriers to alloSCT for older AML patients, more so for older females.