Outcomes of Adult Burkitt Lymphoma Patients Undergoing Hematopoietic Stem Cell Transplantation (HSCT) in CR1 Versus ≥ CR2 - a Single Institution Retrospective Analysis

Abstract

Introduction Burkitt lymphoma (BL) is a rare, aggressive B-cell lymphoma with protean clinical presentation accounting for Methods After regulatory approval, clinical and outcome data for BL patients who underwent HCT from 2000-2019 were collected. Survival outcomes were compared between patients who achieved complete response (CR1), ≥ CR2 and partial response (PR) prior to HCT. Patients who achieved CR after induction chemotherapy were considered CR1; patients requiring more than 1 line of chemotherapy to achieve CR were considered ≥CR2. Results Twenty three patients were identified; the median age was 51 (range: 17-71) years. 10 (43%) patients were identified as low-risk, 11(47%) were high-risk at diagnosis, and risk status was unknown in 2 patients. At the time of diagnosis 5(22%) patients had stage I-II disease, 17 (74%) patients had stage III-IV disease. Four (17%) patients had BM involvement at presentation and 1 had CNS disease. CODOX-M/IVAC-rituximab (2-4 cycles) was the most common first-line chemotherapy regimen (n = 10; 43%). Eight (34.7%) patients achieved CR1, 6 (26%) patients attained CR2 and 9 (39%) patients had a PR or refractory disease after more than 2 lines of chemotherapy. Median time to relapse from diagnosis was 8 months (IQR was 4-78). Median time from diagnosis to HCT was 7 months (IQR 5-9). 22 patients underwent autologous HCT with BEAM conditioning; 8 in CR1, 5 in CR2 and 9 in PR. One patient underwent matched sibling donor allogeneic HCT in CR2. The median follow up for the entire cohort was 35 months (IQR 4-92). Median PFS calculated from D0 of HCT to disease progression, last follow up or death was not reached (NR) for patients in CR1 and CR2, and 6 months in the PR cohort (p = 0.05). Median OS was not reached in patients who were in CR1 and CR2 as compared to 19 months in partial responders (p=0.055). Conclusion In our limited series, autologous HCT in CR1 is associated with an excellent outcome. About 50% of chemo sensitive patients in CR2 can also achieve long term remission after HCT. This finding needs to be validated in a larger cohort.