Optimal timing and impact of allogeneic peripheral blood stem cell transplantation in adult T-cell lymphoblastic lymphoma: insights from a large cohort multi-center real-world study in Shanghai.

In this real-world study, 153 adult T-cell lymphoblastic lymphoma (T-LBL) patients from sixteen centers in Shanghai were enrolled. Out of them, 103 (67.3%) achieved complete remission (CR). The 2-year overall survival (OS) and progression-free survival (PFS) were 56.3% and 47.6%, respectively. In multivariate analysis, CR after induction treatment significantly improved the OS (p = 0.002) and PFS (p = 0.001). Among CR patients, allogeneic peripheral blood stem cell transplantation (allo-PBSCT) significantly lowered the cumulative incidence of relapse (CIR) compared to autologous PBSCT (p = 0.043) and non-SCT (p = 0.001). Among patients undergoing allo-PBSCT in CR, early (within four induction courses) and late CR (after four induction courses) didn't impact the prognosis with similar 2-year OS (p = 0.590), PFS (p = 0.858), CIR (p = 0.50), and non-relapse mortality (NRM) (p = 0.110). Early and deferred allo-PBSCT for early CR patients also yielded similar 2-year OS (p = 0.640), PFS (p = 0.970), CIR (p = 0.994), and NRM (p = 0.974). As a time-dependent covariate, allo-PBSCT presented a positive effect on PFS (p = 0.018) and had a trend toward better OS (p = 0.064). These data suggested that allo-PBSCT should be considered for T-LBL patients upon achieving CR to enhance survival and reduce relapse risk.