Impact of PET-CT status on progression-free survival for relapsed follicular lymphoma patients undergoing autologous stem cell transplant

Abstract

The optimum management approach for patients with relapsed or refractory (R/R) follicular lymphoma (FL) remains uncertain. Autologous stem cell transplantation (autoSCT) is considered a standard option in suitable, younger patients with relapsed FL. AutoSCT is associated with very durable remissions in a minority but also significant, wellestablished toxicities. Although PET status pre-autoSCT is established in diffuse large B-cell lymphoma and Hodgkin lymphoma, no data exists in FL. We describe survival outcomes according to pre-autoSCT PET status according to Lugano criteria (complete metabolic remission (CMR) vs non-CMR) in 172 R/R FL patients within a national, multicentre, retrospective BSBMTCT registry study. Median number of prior lines pre-autoSCT was 3 (range 1-6). Median follow-up post-autoSCT was 27 months (range 3-70). Median progression-free survival (PFS) for all patients post-autoSCT was 28 months (interquartile range 23-36). There was no interaction between age at autoSCT, sex, number of months since last relapse, Karnofsky performance status or comorbidity index (HCT-CI) and achieving CMR pre-autoSCT. Superior progression-free survival was observed in 115 (67%) patients obtaining CMR versus 57 (33%) non-CMR patients (3-year PFS 50% vs. 22%, p=0.011) and by Deauville score pre-autoSCT (continuous variable 1-5, hazard ratio (HR) 1.32, p=0.049). PETstatus was independently associated with PFS (non-CMR HR 2.02, p=0.003), overall survival (non-CMR HR 3.08, p=0.010) and risk for relapse (non-CMR HR 1.64, p=0.046) post autoSCT by multivariable analysis. Our data suggests PET-status pre-autoSCT provides clear prognostic value and may help improve patient selection for autoSCT.