Abstract 3430: Toxicity and long-term outcomes of elderly patients with refractory or relapsed diffuse large B cell lymphoma undergoing autologous stem cell transplantation

Proceedings: AACR 106th Annual Meeting 2015; April 18-22, 2015; Philadelphia, PA Background: High-dose immunochemotherapy followed by autologous stem cell transplantation (Auto-SCT) is the standard treatment for fit individuals with refractory or relapsed diffuse large B cell lymphoma (DLBCL). We conducted a retrospective study to investigate toxicities and long-term clinical outcomes of elderly pts with relapsed or refractory DLBCL undergoing Auto-SCT. Methods: All pts with relapsed or refractory DLBCL undergoing Auto-SCT at our institution between November 2008 and November 2013 were included in the analysis. Prior treatment, secondary age-adjusted international prognostic index (saa-IPI), response to salvage treatment, Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI), Cumulative Illness Rating Scale for Geriatrics (CIRS-G), and stem cell collection yields were recorded for each patient. Treatment complications and long-term clinical outcomes were compared between two age groups (65+ vs. <65 years). Results: 81 individuals underwent Auto-SCT for refractory or relapsed DLBCL. The median age was 60.1 years (24-75 years) and 26 individuals were over 65 years at the time of transplantation. The majority of pts (77%) received salvage therapy with rituximab, ifosfamide, carboplatin, and etoposide followed by AutoSCT with carmustine, cyclophosphamide, and etoposide conditioning. Pts aged greater than 65 years had similar baseline CIRS-G comorbidity scores compared to the younger cohort, but they were more likely to have HCT-CI scores of 3 or more (45% vs. 20%, p = 0.015). The advanced aged group had fewer stem cells collected (4.2 vs 6.1 x106 cells, p = 0.01), despite a trend toward higher number of apheresis sessions (3.2 vs 2.7 days, p = 0.13). However, the two groups experienced similar duration of Auto-SCT hospitalization (21.3 vs 20.9 days), time to neutrophil recovery (10.6 vs 10.4 days), and time to platelet recovery (13.1 vs. 13.1 days). The two groups also experienced similar frequency of blood stream infections, pneumonia, ICU transfers, and hospital readmissions (p = 0.61). One death occurred in each group within the first 100 days (100-day TRM 2.5%), with two additional aged individuals experiencing late deaths due to myeloid neoplasms. After adjusting for age, comorbidities and saa-IPI, response to salvage immunochemotherapy (CR vs. non-CR) remained the only significant predictor of PFS using proportional hazard modeling (HR 0.32, p = 0.002). Conclusions: While prospective clinical trials utilizing Auto-SCT for relapsed large B cell lymphomas have excluded pts over the age of 65, our results suggest selected individuals with advanced age experience an acceptable level of treatment toxicity and have clinical outcomes comparable to younger counterparts. Response to salvage immunochemotherapy, not age, appears to be the strongest predictor of long-term outcomes following Auto-SCT in the setting of relapsed DLBCL. Citation Format: Scott F. Huntington, Boyu Hu, Daniel J. Landsburg, Anthony R. Mato, Sunita D. Nasta, Stephen J. Schuster, Edward A. Stadtmauer, Jakub Svoboda. Toxicity and long-term outcomes of elderly patients with refractory or relapsed diffuse large B cell lymphoma undergoing autologous stem cell transplantation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3430. doi:10.1158/1538-7445.AM2015-3430