Outcomes of Eam Conditioned Autologous Haematopoietic Stem Cell Transplantation for Lymphoma. A Matched Pairs Retrospective Single Centre Study Analysis.
Authors: Loke Justin Ching Ting , Ward Janice , Mahendra Prem , Chaganti Sridhar , Malladi Ram 
Published: October 2019

Abstract
Abstract 3088

Background:
High dose chemotherapy followed by autologous stem cell rescue is superior to salvage chemotherapy alone in relapsed Hodgkin's Lymphoma (HL) and Non-Hodgkin's lymphoma (NHL). A commonly used regimen is BEAM (BCNU, Etoposide, Cytarabine and Melphalan). Unfortunately, BCNU is associated with potentially lethal pulmonary interstitial toxicity, in a dose dependent manner. Therefore, it is often omitted in conditioning regimens for patients who have pre-existing impaired lung function. We aimed to determine the outcomes of patients given this EAM (Etoposide, Cytarabine, Melphalan) schedule in our centre.

Method:
At our unit, from 2000–2010, 338 patients had been transplanted with BEAM conditioning and 23 patients with an EAM regimen. BEAM chemotherapy involved cumulative doses of BCNU at 300 mg/m2, etoposide at 800 mg/m2, cytarabine at 1600 mg/m2 and melphalan at 140 mg/m2. The EAM regimen was the same, except for the omission of BCNU. We wanted to compare overall survival, event free survival and transplant related mortality between the two groups of patients. A matched-pair analysis based on age and sex on a 1:1 basis was conducted. Survival rates were estimated by the Kaplan-Meier method. Differences between the survival distributions were compared with the log-rank test.

Results:
23 patients transplanted with an EAM regimen was matched with an equal number transplanted with a BEAM conditioning regimen. The median age was 53 in both groups. The median follow-up for patients alive was 3.2 years. Further baseline characteristics of the two groups are described in table 1. Other than a slight predominance of more advanced disease in the BEAM cohort, the two groups were evenly matched.
Survival estimates were statistically significantly poorer for the EAM group compared to the BEAM group. The median overall survival for the EAM cohort was 29 months compared to 77 months (p=0.03) for the matched BEAM cohort. The median event free survival for the EAM cohort was 11 months compared to 63 months (p=0.02) for the BEAM cohort. The 100 day transplant related mortality was 8.7% for both cohorts. During the follow-up period 11 patients died of disease related causes in the EAM group compared to 6 in the BEAM group.

Conclusion:
Despite the prevalence of pre-existing lung disease in the EAM group of patients, the conditioning was reasonably well tolerated. Our analysis suggests that patient transplanted with an EAM regimen had an inferior survival outcome to patients treated with the standard BEAM regimen. This data provides evidence for the importance of BCNU in lymphoma control; consideration should be given to a reduction in BCNU dosage, rather than simple omission, for patients with borderline lung function results. Collaboration with other centres is warranted to determine if this experience with EAM is replicated elsewhere.

Disclosures:
No relevant conflicts of interest to declare.