Lymphocyte recovery and infused CD34+ cells dose: Effect on the evolution after stem cell autotransplantation

Outcome of autologous hematopoietic stem cell transplant in older patients with B cell lymphoma when selected for fitness and chemosensitive disease

BACKGROUND

Autologous hematopoietic stem cell transplantation (AHSCT) in the older population is associated with an increased risk of morbidity and mortality. Determination of the hematopoietic cell transplant comorbidity index (HCT-CI) has contributed to improve patient selection while allowing prediction of their non-relapse mortality (NRM). The goal of this study was to identify factors influencing both safety and efficacy of AHSCT in an older non-Hodgkin lymphoma (NHL) population to better select those who will benefit from this intervention in the Canadian context of a single-payer government healthcare program.

METHODS

This single center, retrospective study, examined clinical outcomes in 90 consecutive older patients (≥60 years old) with B-cell NHL treated with AHSCT between 2008 and 2014.

FINDINGS

Median age was 63 (60-69) at time of transplantation. The HCT-CI risk score was low, intermediate and high in 34%, 40% and 26% of patients, respectively. NRM was 1% at 100 days and one-year post transplant and not influenced by age. At a median follow-up of 52 months, median progression-free survival (PFS) was 56 months while median overall survival (OS) was still not reached. Stable and progressive disease status at time of transplantation were associated with a lower PFS (HR 2.94) and OS (HR 3.91). BEAC conditioning and a graft cell dose  5 × 10⁶ CD34+/kg led to faster recovery, decreased toxicity and resource consumption.

INTERPRETATION

In the older population, AHSCT is safe and optimal when restricted to fit chemosensitive patients.