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.