[Outcome of 126 adolescent and adult T-cell acute leukemia/lymphoma patients and the prognostic significance of early T-cell precursor leukemia subtype]

Comparison of characteristics and outcomes on ETP-ALL/LBL and non-ETP ALL patients receiving allogeneic hematopoietic stem cell transplantation

Objective

This study aims to compare the characteristics of early T-cell precursor acute lymphoblastic leukemia/lymphoma (ETP-ALL/LBL) and non-ETP ALL patients and the outcomes of these patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT).

Method

A total of 57 patients with T-cell acute lymphoblastic leukemia/lymphoma receiving allo-HSCT at our center between January 2016 and March 2022 were enrolled in the study. Twenty-eight patients were diagnosed as ETP-ALL/LBL (28/57, 49.12%) in the cohort.

Results

The baseline characteristic was not significantly different between the two groups. The median time for myeloid engraftment was 14 days (ranged from 11 to 21) versus 14 days (ranged from 10 to 20) (P = 0.067) and 18 days (ranged from 12 to 27) versus 15.5 days (ranged from 12 to 72) (P = 0.183) for platelet engraftment in the ETP-ALL/LBL and non-ETP ALL groups, respectively. There was no significant difference in 5-year overall survival (54.74% ± 10.33% vs. 64.20% ± 10.30%, P = 0.786), relapse-free survival (56.22% ± 10.11% vs. 57.17% ± 12.71%, P = 0.841), cumulative incidence of relapse (30.14% ± 9.85% vs. 22.79% ± 8.24%, P = 0.774), and non-relapse mortality (19.52% ± 8.99% vs. 25.95% ± 14.44%, P = 0.967) between the two groups. The incidence of acute graft versus host disease (aGVHD) (P = 0.922), II-IV aGVHD (P = 0.940), III-IV aGVHD (P = 0.664), cytomegalovirus infection (P = 0.862), Epstein-Barr virus infection (P = 0.610), and severe bacterial infection (P = 0.145) was also similar.

Conclusion

The prognosis of patients with ETP-ALL/LBL was similar to non-ETP ALL patients when they received allo-HSCT.

Relevance of flow cytometry categorization and end-of-induction measurable residual disease assessment in pediatric and adult T-lymphoblastic leukemia patients

Background

T-lymphoblastic leukemia (T-ALL) patients expressing myeloid/stem cell antigens are classified as early T-cell precursor lymphoblastic leukemia (ETP-ALL) or near-ETP-ALL.

Methods

Clinico-laboratory profiles, flow cytometric end-of-induction measurable residual disease (EOI-MRD), and survival of treatment naïve T-ALL patients were analyzed according to their immunophenotypic subtypes.

Results

Among 81 consecutive T-ALL patients diagnosed, 21% (N=17) were ETP-ALL and 19% (N=15) were near-ETP-ALL. EOI-MRD was detectable in 39% of the 59 samples tested (31.6% of pediatric samples and 52.4% of adult samples). The frequency of EOI-MRD positivity was significantly higher among ETP-ALL (75%, P=0.001) and near-ETP-ALL (71%, P=0.009) patients compared to that in conventional-T-ALL (con-T-ALL) patients (22.5%). CD8 (P=0.046) and CD38 (P=0.046) expressions were significantly upregulated in the EOI blasts of con-T-ALL and ETP-ALL samples, respectively. The 2-year rates of overall (OS), relapse-free (RFS), and event-free survival (EFS) among the T-ALL patients (pediatric vs. adult) was 79.5% vs. 39.8% (P<0.001), 84.3% vs. 60.4% (P=0.026), and 80.3% vs. 38% (P<0.001), respectively. Univariate analysis revealed that 2-year EFS and RFS of pediatric T-ALL patients was independent of T-ALL subtype and was influenced only by EOI-MRD status. However, 2-year OS, RFS, and EFS among adult T-ALL patients were EOI-MRD independent and influenced only by the near-ETP-ALL phenotype.

Conclusion

Two-year survival among pediatric and adult T-ALL patients is attributed to EOI-MRD status and near-ETP-ALL phenotype, respectively.

Comparison of Early T-Cell Precursor and Non-ETP Subtypes Among 122 Chinese Adults With Acute Lymphoblastic Leukemia

Background: Adult T-cell acute lymphoblastic leukemia (T-ALL) is a rare hematological malignancy and significantly linked to poor outcomes. Early T-cell precursor (ETP) leukemia is a unique subtype of T-ALL. The aim of this study is to compare the differences between ETP and non-ETP ALLs in China.

Methods: We retrospectively analyzed the records of 122 adult T-ALL patients diagnosed and treated at our center between January 2014 and June 2019. All the patients enrolled were categorized into ETP and non-ETP ALL by immunophenotype, and further statistical analyses about clinical data and prognostic factors were performed.

Results: Among the 122 cases, the male-to-female ratio was 2.8:1, and the median age is 29 (range, 16–82) years. Except for 10 patients with insufficient immunophenotyping results, 47.3% (53/112) are ETP and 52.7% (59/112) are non-ETP. Compared with non-ETP patients, ETP-ALL patients had lower white blood cell counts and lactate dehydrogenase levels, while they were older and had higher platelet counts and fibrinogen levels (all p < 0.05). Complete remission (CR) was achieved in 68.0% (83/122) of patients, 64.2 and 76.3% in ETP and non-ETP, respectively (p = 0.160). In total, 44.6% (37/83) of patients relapsed. Allogeneic stem cell transplantation (allo-SCT) was successfully performed in 36.1% (44/122) of patients, of which 79.5% (35/44) were in CR1. With a median follow-up of 9.1 (range, 0.5–70.3) months, the estimated 2-year overall survival (OS) and relapse-free survival (RFS) rates for the cohort were 38.0 ± 5.1 and 39.1 ± 6.3%, respectively. In the ETP group, the 2-year OS rate was 40.7 ± 8.2% and the RFS rate was 47.2 ± 10.7%, while in the non-ETP group, the 2-year OS rate was 37.9 ± 7.0% and the RFS rate was 39.2 ± 8.3% (both p > 0.05). In the landmark analysis of CR1 patients who had a survival of more than 6 months, the allo-SCT group had significantly better survival outcomes than the chemotherapy group, and the 2-year OS rates and RFS rates were 80.1 ± 7.3 vs. 28.4 ± 8.4% and 68.9 ± 8.8 vs. 12.8 ± 7.2%, respectively (both p < 0.0001). A multivariate analysis suggests that allo-SCT acts as an independent prognostic factor for both OS and RFS.

Conclusions: Our results revealed that ETP accounted for a high proportion of T-ALL in Chinese. There are no CR rates and prognosis differences between ETP and non-ETP. Allo-SCT in CR1 can significantly improve patients' survival.