Therapy-related B-lymphoblastic leukemia associated with Philadelphia chromosome and MLL rearrangement: Single institution experience and the review of the literature

Mutational patterns in therapy-related acute lymphoblastic leukemia subgroups: one step closer to unveiling the genetic odyssey

There is increasing evidence that therapy-related acute lymphoblastic leukemia (trALL) resulting from chemo- and/or radiotherapy represents a distinct entity. However, apart from KMT2A rearrangements, which have been repeatedly reported in this subgroup, the relevance of other aberrations remains controversial due to divergent study results and sparse molecular analyses. Within our ALL patient cohort, 15% (n = 19/131) met the criteria for trALL with a high proportion of Ph + and KMT2A rearrangements. On the molecular level, the most frequently observed mutation was KMT2D, followed by CDKN2A, KRAS and DNMT3A. No TP53 mutation was detected. Outcome was particularly poor in Ph + trALL compared to Ph+ de novo ALL, which seemed to be mitigated by allogeneic stem cell transplantation. Our findings further define trALL as a distinct entity but highlight the need for further molecular genome sequencing of somatic and germline variants to advance our understanding of trALL.

A Case of Therapy-Related Acute Lymphoblastic Leukemia Following the treatment of Acute Myeloid Leukemia

Therapy-related acute lymphoblastic leukemia represents a distinct entity associated with inferior survival compared with de novo acute lymphoblastic leukemia. It consists of a subset of patients who have had exposure to chemotherapy or radiation for a previous malignancy. Here, we describe a case of acute myeloid leukemia who later developed precursor B cell acute lymphoblastic leukemia and discuss the current relevant literature. Our case highlights the importance of classifying therapy-related acute lymphoblastic leukemia as a separate as entity based on its biologic and clinical features.

Outcomes of therapy-related acute lymphoblastic leukemia in adults after allogeneic stem cell transplantation

INTRODUCTION

Therapy-related acute lymphoblastic leukemia (t-ALL) is an increasingly recognized subset of therapy-related acute leukemia. There are limited data on the role of allogeneic hematopoietic stem cell transplantation (HSCT) in t-ALL. Recent reports suggest comparable outcomes of t-ALL with de novo ALL after HSCT.

PATIENTS AND METHODS

We retrospectively reviewed all patients of t-ALL who underwent HSCT at our center. Patients were analyzed for prior malignancy, therapy, time to diagnosis of t-ALL, clinical, laboratory characteristics, transplant details, relapse-free survival (RFS), and overall survival (OS).

RESULTS

Eighteen patients (M:F ratio 1:1; Median age 44 years) underwent HSCT for t-ALL. Median latent period from primary malignancy to t-ALL was 44.8 months. 11q23 rearrangement and t(9;22) were present in 33.3% and 22.2% patients, respectively. Stem cell donors were matched related, matched unrelated, and haploidentical in 27.8% (n = 5), 55.6% (n = 10), and 16.7% (n = 3) patients, respectively. Five patients died before D+ 100 (27.8%). Estimated 2-year RFS and OS were 47.1% and 51.8%, respectively. We did not find any pretransplant and post-transplant risk factors that were predictive of improved OS or RFS after multivariate analysis.

CONCLUSIONS

Allogeneic HSCT outcomes in t-ALL were comparable to HSCT outcomes in de novo ALL. Multicenter studies with more patients and longer follow-up may provide factors affecting outcome and survival.

Co-existence of IL7R high and SH2B3 low expression distinguishes a novel high-risk acute lymphoblastic leukemia with Ikaros dysfunction

Acute lymphoblastic leukemia (ALL) remains the leading cause of cancer-related death in children and young adults. Compared to ALL in children, adult ALL has a much lower cure rate. Therefore, it is important to understand the molecular mechanisms underlying high-risk ALL and to develop therapeutic strategies that specifically target genes or pathways in ALL. Here, we explored the IL7R and SH2B3 expression in adult ALL and found that IL7R is significantly higher and Sh2B3 lower expressed in B-ALL compared to normal bone marrow control, and the IL7R^highSH2B3^low is associated with high-risk factors, and with high relapse rate and low disease-free survival rate in the patients. We also found that Ikaros deletion was associated with the IL7R^highSH2B3^low expression pattern and Ikaros directly binds the IL7R and SH2B3 promoter, and suppresses IL7R and promotes SH2B3 expression. On the other hand, casein kinase inhibitor, which increases Ikaros function, inhibits IL7R and stimulates SH2B3 expression in an Ikaros dependent manner. Our data indicate that IL7R^highSH2B3^low expression distinguishes a novel subset of high-risk B-ALL associated with Ikaros dysfunction, and also suggest the therapeutic potential for treatment that combines casein kinase inhibitor, as an Ikaros activator, with drugs that target the IL7R signaling pathway.