2022 EBMT Voice of China TBI conditioning regimen can improve survival in patients with T-LBL treated with allo-HSCT

The optimal consolidation regimen for adults with T-lymphoblastic lymphoma (T-LBL) has not been established
.

Autologous hematopoietic stem cell transplantation (auto-HSCT) has been used for consolidation therapy to reduce the risk of disease recurrence, but the risk of recurrence remains high, with a 5-year recurrence rate of 26.
5%-56%
.

A previous study (Liu et al.
) showed that compared with chemotherapy alone or single auto-HSCT, tandem auto-HSCT could reduce the progression/relapse rate, but the 3-year progression/relapse rate was still as high as 26.
5%
.

Consolidation of allogeneic HSCT (allo-HSCT) for T-LBL can reduce recurrence rates, especially in high-risk patients, but may increase non-relapse mortality (NRM) compared with auto-HSCT
.

Previous reports (Levine JE et al.
) showed that the cumulative recurrence rate (CIR) at 1 and 5 years after allo-HSCT in T-LBL patients was significantly lower than that in auto-HSCT (32% vs 46%, respectively, P=0.
05; 34% vs 56%, P=0.
004), but NRM at 6 months after allo-HSCT was higher than auto-HSCT (18% vs 3%, P=0.
002)
.

Over the past few decades, the optimization of graft-versus-host disease (GVHD) prevention strategies and the prevention and control of complications such as infection has resulted in a significant decline in NRM
.

There is a clinical need to explore the optimal conditioning regimen for allo-HSCT to reduce the risk of recurrence and improve survival in adult T-LBL patients
.

Methods This study retrospectively analyzed 40 T-LBL patients who underwent allogeneic peripheral blood stem cell transplantation (allo-PBSCT) in the First People's Hospital of Shanghai Jiaotong University.
BU) two pretreatment schemes to determine the best pretreatment scheme
.

The results suggest that a TBI-based regimen can reduce the risk of recurrence and improve survival in adult high-risk T-LBL patients
.

Results 23/40 (57.
5%) patients received total body irradiation (TBI)-based conditioning regimen, and 17/40 (42.
5) patients received BU-based conditioning regimen
.

The time to neutrophil and platelet engraftment was similar in the TBI and BU groups (P=0.
283 and P=0.
368)
.

 The cumulative incidence (CI) of grade II-IV acute GVHD was significantly increased in the TBI group compared with the BU group (13.
04% vs 0%, P=0.
000)
.

The risk of recurrence after transplantation was significantly lower in the TBI group, with a 2-year CIR of 9.
11% and 49.
58%, respectively (P=0.
006)
.

 The 2-year overall survival (OS) and recurrence-free survival (RFS) rates in the TBI group were 83.
0% (95%CI, 63.
4-100%) and 74% (95%CI, 54.
4-93.
6%), respectively, which were higher than those in the BU group 35.
0% (95%CI, 0.
0%-72.
2%) and 50.
0% (95%CI, 24.
5-75.
4%) (P=0.
020; P=0.
081)
.

 In multivariate analysis, TBI-based conditioning regimen, as an independent prognostic factor, significantly reduced recurrence risk (SHR 0.
030; 95% CI, 0.
002-0.
040; P=0.
000) and improved OS (HR 0.
121; 95%) CI, 0.
021-0.
683; P=0.
017)
.

 Figure (A) Cumulative recurrence rate (CIR) of CR patients at the time of transplantation; (B) CIR of all patients; (C) NRM (P=0.
140) and recurrence-related mortality (P=0.
11) of all patients.
showed that adult T-LBL patients who achieved a CR at transplant may have a favorable prognosis when using a TBI-based conditioning regimen
.

This suggests that a TBI-based conditioning regimen may be the optimal regimen for adult T-LBL patients undergoing allo-HSCT
.

However, this study is a retrospective study with a relatively small sample size and short follow-up time, which has certain limitations
.

Therefore, further studies with larger sample size and longer follow-up time are needed to validate this conclusion
.

 References: J.
Niu, Z.
Chen, H.
Qiu et al.
TOTAL BODY IRRADIATION BASED CONDITIONING REGIMEN IMPROVE THE SURVIVAL OF PATIENTS WITH T-CELL LYMPHOBLASTIC LYMPHOMA AFTER ALLOGENEIC PERIPHERAL BLOOD STEM CELL TRANSPLANTATION The 48th Annual Meeting of the EBMT.
Abstract P024.
Editor: Uni Reviewer: Mia Typesetting: Quinta pokes "read the original text", let's make progress together