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

Abstract

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 TALL. 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 TALL 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. Zhang et al. Adult TALL in Chinese Conclusions: Our results revealed that ETP accounted for a high proportion of TALL in Chinese. There are no CR rates and prognosis differences between ETP and non-ETP. Allo-SCT in CR1 can significantly improve patients' survival.

Impact of disease status at allogeneic stem cell transplantation on adolescent and young adult patients with early T‐cell precursor acute lymphoblastic leukemia

“…In this study, patients in CR had a 2‐year OS of 61.7%, and even high‐risk CR patients had a 2‐year OS of 58.7%. This result is similar to that from other reports, supporting a survival benefit for allo‐HSCT in AYA patients with ETP‐ALL 7,10,14 . In fact, the rate of allo‐HSCT was believed to be the main reason for the prognostic variance of patients with the ETP immunophenotype between different studies.…”

“…Previous studies have demonstrated that allo‐HSCT results in superior outcomes compared with chemotherapy alone 12,13 . Most studies show that ETP‐ALL patients also benefit from allo‐HSCT, but the number of published studies is limited and all studies only include a relatively small number of patients 7,10,14 . To date, the largest report has been from GRAALL (Group for Research on Adult Acute Lymphoblastic Leukemia) 7 .…”

Expression of aberrant markers in acute leukemia at South Egypt Cancer Institute: A retrospective study

“…From our T-ALL patients, ETP-ALL represented 12.7%, which agrees with the results of many studies in which ETP-ALL ranged from 9.7% to 20% of their T-ALL cases (43)(44)(45)(46)(47). But a different study in adult Chinese T-ALL patients by Zhang et al, (2020), ETP-ALL was found in 47.3% (48). This variation in frequency may be due to difference in sample size, ethinity and age groups.…”

The Clinical Characteristics and Prognosis of AYA and Older Adult ETP-ALL/LBL: A Real-World Multicenter Study in China

“…Similar results were found in other studies ( 3 , 7 ). However, recently, some studies have found that the prognosis of ETP-ALL was not significantly different from that of typical T-ALL ( 5 , 8 , 9 ). The largest published report on ETP was from Zhang et al., in which 53 ETP-ALL patients were included.…”

“…ETP-ALL has been reported in 13~16% of T cell acute lymphoblastic leukemia (T-ALL) cases in children ( 1 , 2 ) and 17~32% in adults ( 3 , 4 ). In China, ETP-ALL accounts for approximately 45% of adult T-ALL ( 5 ). ETP-ALL/LBL has a unique gene mutation expression profile, mainly manifested as a higher incidence of mutations in genes regulating cytokine receptor and RAS signaling, which was similar to the mutational spectrum of myeloid tumors ( 6 ).…”