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

Burkitt lymphoma (BL) is a rare, aggressive B-cell lymphoma with protean clinical presentation accounting for < 1% of adult non-Hodgkin lymphomas in the United States. High dose, intensive chemotherapy regimens like CODOX-M/IVAC, HyperCVAD, and DA-REPOCH achieve a 5-yr OS rate of 60-80%. However, HCT remains the only curative option in relapsed patients. Herein, we describe our single center experience of BL patients who underwent HCT. 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. 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). 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. [ABSTRACT FROM AUTHOR]