Hematopoietic cell transplantation for mantle cell lymphoma: Predictive value of pretransplant positron emission tomography/computed tomography and bone marrow evaluations for outcomes

Background The prognostic roles of 18F-fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging and marrow involvement evaluation on outcomes following autologous and allogeneic hematopoietic cell transplantation (HCT) for mantle cell lymphoma (MCL) are uncertain and require more data. Patients and Methods We categorized 66 patients with MCL who received HCT (38 autologous and 28 allogeneic) on the basis of pre-HCT residual disease (RD) status as assessed by marrow MCL morphology and flow/molecular analysis and PET/CT imaging to RD positive (RD⁺) (either or both measures positive) and RD^- (both negative). We analyzed the predictive value of these RD detection methods on transplant outcomes. Results The 2-year relapse rate after autograft was significantly higher in pre-HCT RD⁺ patients (46% [95% CI 16-77%]) than in patients who were RD^- (19% [95% CI 0-42%]; P =.02), leading to worse 5-year disease-free survival (DFS) in RD⁺ patients (46% [95% CI 14%-73%] vs. 68% [95% CI 33-87%], P =.04). In multivariate analysis, RD⁺ status was associated with a reduction in DFS (hazard ratio, 5.6; P =.02). Most allogeneic HCT recipients had advanced disease and most were RD⁺ (12 PET/CT⁺; 5 marrow-positive). The 5-year DFS and relapse rates after allogeneic HCT were 34% and 25% for all patients and 40% and 33% for RD⁺ recipients, suggesting that active disease at the time of allograft does not preclude long-term remissions in advanced MCL. Conclusion Both autologous and allogeneic HCT lead to promising long-term survival. RD detected prior to autograft was associated with increased relapse and worse 5 year DFS. Allograft recipients had favorable long-term outcomes even in presence of pre-HCT detectable disease.