Comparison of efficacies of haploidentical transplantation and matched sibling donor transplantation in treating T-cell lymphoblastic lymphoma.

OBJECTIVE: To investigate the differences in efficacy and safety between haploidentical donor hematopoietic stem cell transplantation (HID-HSCT) and matched sibling donor HSCT (MSD-HSCT) in patients with T-cell lymphoblastic lymphoma (T-LBL).

METHODS: In this retrospective analysis, we enrolled 38 patients who had undergone allogeneic HSCT at our institution between 2013 and 2021. The study participants included 28 patients who underwent HID-HSCT and 10 patients who underwent MSD-HSCT. We compared the patient characteristics and treatment effectiveness and safety between the two groups and evaluated potential prognostic variables for patients with T-LBL.

RESULTS: The median follow-up durations in the HID-HSCT and MSD-HSCT groups were 23.5 (range: 4-111) and 28.5 (range: 13-56) months, respectively. All patients showed full-donor chimerism after hematopoietic stem cell transplantation (HSCT). Except for two patients in the HID-HSCT cohort who developed poor graft function, all patients showed neutrophil and platelet engraftments after HSCT. The cumulative incidences of grades III-IV acute graft-versus-host disease were 37.5% and 28.57% in the HID-HSCT and MSD-HSCT groups, respectively (p = 0.84). The cumulative incidences of limited (34.13% vs. 28.57%, p = 0.82) and extensive (31.22% vs. 37.50%, p = 0.53) chronic graft-versus-host disease did not differ between the two cohorts. In the HID-HSCT and MSD-HSCT cohorts, the estimated 2-year overall survival rates were 70.3% (95% confidence interval [CI]: 54.9%-90.0%) and 56.2% (95% CI: 31.6%-100%), respectively (p = 1.00), and the estimated 2-year progression-free survival (PFS) rates were 48.5% (95% CI: 32.8%-71.6%) and 48.0% (95% CI: 24.6%-93.8%), respectively (p = 0.94). Furthermore, the Cox proportional-hazards model showed that a positive positron emission tomography/computed tomography (PET/CT) status before HSCT in patients who had completed chemotherapy was an independent risk factor for PFS in the multivariate analysis (p = 0.0367).

CONCLUSION: This study showed that HID-HSCT had comparable effectiveness and safety to MSD-HSCT in treating T-LBL. HID-HSCT could serve as an alternate treatment option for T-LBL in patients without an eligible identical donor. Achievement of the PET/CT-negative status before HSCT may contribute to better survival.