Prompt Autologous Hematopoietic Stem Cell Transplant in Patients with Large B-Cell Lymphoma Is Associated with Lower Rates of Progression of Disease Prior to Transplant

Introduction Timely autologous hematopoietic stem cell transplantation (ASCT) is considered to be of the essence when used as consolidation therapy in large B-cell lymphoma (LBCL). It is common practice for patients awaiting ASCT to continue receiving chemotherapy to ensure disease control. Objectives The purpose of this study is to evaluate this common practice, for which evidence is lacking, in relation to the timing of transplants. Methods We retrospectively reviewed the records of patients with LBCL who were considered for ASCT at our institution between 2011 and 2022. A transplant was described as “delayed” by the treating physician. Receipt of “additional” chemotherapy in patients pending ASCT was defined as the continuation of therapy past the number of minimum planned cycles ± radiologic confirmation of partial or complete response (PR/CR) at the treating physician's discretion. Patient groups were compared by Fisher's exact test. Results Included were 87 patients with LBCL who had achieved either PR or CR to their latest chemoimmunotherapy and were being evaluated for ASCT. Median age was 61 (range, 18-77) years and 55 (63%) were men. The majority, 62 (71%), of patients had advanced stage (III-IV) lymphoma with the most common entity identified as diffuse large B-cell lymphoma, not otherwise specified, diagnosed in 60 (69%) patients. ASCT was used for relapsed/refractory LBCL in 74 (85%) patients. Transplant was delayed in 20 (23%) patients (12 due to medical issues, 5 due to administrative issues, 3 due to both), 22 (25%) patients (6 delayed) received additional chemotherapy, and 14 (16%) patients (13 in CR, 1 in PR) had progression of disease (PD) while awaiting transplant. After their initial evaluation, 12 patients did not undergo transplant: 7 experienced PD requiring another line of therapy, 3 failed stem cell mobilization/collection, and 2 were ineligible due to high-risk comorbidities. For those who underwent a non-delayed transplant (n= 58), the median time between initial ASCT consult and ASCT was 79 (range, 30-305) days, while for those who underwent a delayed transplant (n= 17) 144 (range, 55-415) days. Delay of transplant was associated with significantly higher PD prior to transplant (OR= 4.61, P= 0.015) (Figure 1). Additional chemotherapy use did not predict significantly lower PD prior to transplant (OR= 1.83, P= 0.33) (Figure 2), including in patients whose transplant was delayed (OR= 0.9, P= 0.99). Conclusion Timely ASCT is associated with less progression of disease prior to transplant in patients with LBCL, while additional chemotherapy while awaiting ASCT is not. The role of chemotherapy continuation past PR/CR status in this group of patients needs to be studied prospectively.