Disease Risk Index is Important Prognostic Factor for Older HCT Patients

A study of 196 patients age 60-75 years with hematologic malignancies undergoing reduced-intensity conditioning (RIC) hematopoietic cell transplantation (HCT) has found that the Disease Risk Index (DRI) score is a significant prognostic factor for post-transplant relapse, treatment failure and mortality.

The DRI classified 12 patients (6.1%) as low risk (LR), 146 patients (74.5%) as intermediate risk (IR), and 38 patients (19.4%) as high risk (HR). All patients in this single-center study were transplanted between 2000 and 2014.

The table below shows 2-year outcomes for all patients, plus a univariate comparison of LR/IR vs. HR patients. Results indicate that a high-risk DRI score predicted significantly higher relapse incidence, in addition to worse overall and disease-free survival.

2-year HCT outcomes
  All patients LR/IR patients HR patients p-value
 Overall survival 47% 52% 29% <0.01
 Disease-free survival 39% 44% 21% <0.01
 Relapse incidence 30% 26% 44% <0.01

In a multiple regression analysis, HR DRI was significantly associated with increased risk of relapse (HR, 2.07; 95% CI, 1.34-3.33; p=0.02) and treatment failure (HR, 2.07; 95% CI, 1.35-3.18; p<0.01) and decreased overall survival (HR, 2.11; 95% CI, 1.34-3.33; p<0.01).

Two-year treatment-related mortality (TRM) was 29%, which was similar for all DRI groups. Survival and TRM results were also similar between age groups 60 to 64 vs. ≥65.

The authors noted that the limitations of using DRI include a lack of evaluation for minimal residual disease status and molecular subtype of disease, which previous research has shown to be prognostic of HCT outcomes in patients with acute myeloid leukemia and myelodysplastic syndromes.

The researchers conclude that despite the limitations of the DRI, their study “supports continued use of RIC transplantation as a potentially curative therapy for elderly patients with good performance status and comorbidity scores.”

He F, et al. Biol Blood Marrow Transplant

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