Therapy-related acute lymphoblastic leukemia: Where do we stand with regards to its definition and characterization?

Therapy-Related B-cell Acute Lymphoblastic Leukemia: A Case Series and Literature Review

Therapy-related B-cell acute lymphoblastic leukemia (B-ALL) is a rare disease associated with poor cytogenetics and inferior survival outcomes. In this case series, we present two cases of B-ALL following treatment for invasive ductal carcinoma of the breast and squamous cell carcinoma of the tongue, respectively, along with a third case of B-ALL arising in a patient with chronic lymphocytic leukemia after treatment. The most common cytogenetic abnormalities observed in these patients were t(9;22) and monosomy 7. This case series underscores the importance of recognizing therapy-related B-ALL as a distinct clinical entity, which plays a crucial role in ALL risk classification and the long-term management of both solid and hematologic cancer survivors.

Pediatric therapy-related hematologic neoplasms show enrichment for KMT2A rearrangement and lymphoblastic phenotype

In children, therapy-related hematologic neoplasms (t-HN) are uncommon. Many are driven by genetic events independent of clonal hematopoiesis. We sought to understand the clinical and genetic factors of pediatric t-HN in a large independent cohort. Fifty-six t-HN were retrospectively identified. Chromosome microarray, next-generation and/or RNA sequencing were performed. Patients had primary hematologic, solid, or central nervous system tumors. t-HN included myeloid (t-MN) and lymphoblastic (t-ALL) phenotypes. Approximately half of the cases harbored KMTA2A rearrangement (KMT2Ar). Among t-HN without KMT2Ar, genetic drivers were heterogeneous, including diverse fusions or aneuploidy. Approximately 18% harbored 17p deletions and/or TP53 mutations. EFS/OS was not associated with t-HN lineage or KMT2Ar, but HSCT was associated with improved EFS and OS. We detail one of the largest cohorts to date of pediatric t-HN, confirming frequent KMT2Ar and t-ALL.

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.

Management of ALL in adults: 2024 ELN recommendations from a European expert panel

ABSTRACT

Experts from the European Leukemia Net (ELN) working group for adult acute lymphoblastic leukemia have identified an unmet need for guidance regarding management of adult acute lymphoblastic leukemia (ALL) from diagnosis to aftercare. The group has previously summarized their recommendations regarding diagnostic approaches, prognostic factors, and assessment of ALL. The current recommendation summarizes clinical management. It covers treatment approaches, including the use of new immunotherapies, application of minimal residual disease for treatment decisions, management of specific subgroups, and challenging treatment situations as well as late effects and supportive care. The recommendation provides guidance for physicians caring for adult patients with ALL which has to be complemented by regional expertise preferably provided by national academic study groups.

A case report of secondary B-cell acute lymphoblastic leukemia treated with a combination of FLT3 inhibitor and decitabine

Secondary acute lymphoblastic leukemia (s-ALL) refers to acute lymphoblastic leukemia that occurs after a previous malignant tumor, including therapy-related acute lymphoblastic leukemia (t-ALL) and prior malignant tumor acute lymphoblastic leukemia (pm-ALL). We report a case of a 51-year-old female patient who developed acute lymphoblastic leukemia 14 years after being diagnosed with diffuse large B-cell lymphoma (DLBCL). The patient was unresponsive to conventional chemotherapy for acute lymphoblastic leukemia (ALL) and achieved remission with a combination of sorafenib and decitabine based on the molecular biology characteristics of her B-ALL.

Allogeneic hematopoietic cell transplantation is equally effective in secondary acute lymphoblastic leukemia (ALL) compared to de-novo ALL-a report from the EBMT registry

Secondary acute lymphoblastic leukemia (s-ALL) comprises up to 10% of ALL patients. However, data regarding s-ALL outcomes is limited. To answer what is the role of allogeneic hematopoietic cell transplantation (HCT) in s-ALL, a matched-pair analysis in a 1:2 ratio was conducted to compare outcomes between s-ALL and de novo ALL (dn-ALL) patients reported between 2000-2021 to the European Society for Blood and Marrow Transplantation registry. Among 9720 ALL patients, 351 (3.6%) were s-ALL, of which 80 were in first complete remission (CR1) with a known precedent primary diagnosis 58.8% solid tumor (ST), 41.2% hematological diseases (HD). The estimated 2-year relapse incidence (RI) was 19.1% (95%CI: 11-28.9), leukemia-free survival (LFS) 52.1% (95%CI: 39.6-63.2), non-relapse mortality (NRM) 28.8% (95%CI: 18.4-40), GvHD-free, relapse-free survival (GRFS) 39.4% (95%CI: 27.8-50.7), and overall survival (OS) 60.8% (95%CI: 47.9-71.4), and did not differ between ST and HD patients. In a matched-pair analysis, there was no difference in RI, GRFS, NRM, LFS, or OS between s-ALL and dn-ALL except for a higher incidence of chronic GvHD (51.9% vs. 31.4%) in s-ALL. To conclude, patients with s-ALL who received HCT in CR1 have comparable outcomes to patients with dn-ALL.

'Secondary' acute lymphoblastic/lymphocytic leukemia - done playing second fiddle?

Acute lymphoblastic/lymphocytic leukemia (ALL) occurring post-cancer diagnosis (secondary ALL - sALL) is increasingly recognized as a discrete entity, constituting up to as much as 5-10% of all new ALL diagnoses, and carrying its own biologic, prognostic and therapeutic significance. In this review, we will outline the history and current state of research into sALL. We will explore the evidence for differences underlining its existence as a distinct subgroup, as well as examining what might be driving such differences etiologically, including prior chemotherapy. We will examine these distinctions on population-, chromosomal-, and molecular-levels, and we will consider whether they translate to differences in clinical outcome, and whether they do - or should - warrant differences in treatment selection.

Treatment-Associated Acute Lymphoblastic Leukemia Following Autologous Hematopoietic Stem Cell Transplant and Lenalidomide Maintenance in Patients With Multiple Myeloma

Secondary malignancies including leukemia are an increasing concern in patients with prior primary malignancies treated with alkylating agents or topoisomerase II inhibitors. These can also be referred to as therapy-related leukemia. Therapy-related leukemia most commonly results in myelodysplastic syndrome or acute myeloid leukemia. The alkylating agent can cause chromosomal aberrations typically manifest as deletions in chromosome 11 or loss of part of complete loss of chromosomes 5 and 7. Conversely, acute lymphoblastic leukemia (ALL) has been described following maintenance therapy with immunomodulatory (IMiD) drugs pomalidomide, thalidomide, and lenalidomide. We present a case of a 71-year-old man with a history of multiple myeloma (MM) maintained on lenalidomide after stem cell transplant who presented with treatment-associated ALL. At time of leukemic presentation, chromosomal analysis showed a near-triploid clone consistent with masked double low hyplodiploidy which is associated with a poor prognosis. The patient had a deletion of the long arm of chromosome 5 which has been described in prior case reports with ALL secondary to lenalidomide therapy. There are explicit mechanisms in the literature, which have been attributed to development of ALL after exposure to thalidomide or lenalidomide. At time of submission, there are 20 cases described in the literature linking ALL to IMiD drugs. We describe a case and review the mechanisms of lenalidomide-associated ALL.

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.

Comparative study of therapy-related and de novo adult b-cell acute lymphoblastic leukaemia

We report a comparative analysis of patients with therapy‐related acute lymphoblastic leukaemia (tr‐ALL) vs de novo ALL. We identified 331 patients with B‐ALL; 69 (21%) were classified as tr‐ALL. The most common prior malignancies were breast (23·2%) and plasma cell disorders (20·3%). Patients with tr‐ALL were older (median 63·2 vs. 46·2 years, P < 0.001), more often female (66·7% vs. 43·5%, P < 0·001), and more likely to have hypodiploid cytogenetics (18·8% vs. 5·0%, P < 0·001). In multivariable analysis, patients with tr‐ALL were less likely to achieve complete remission [odds ratio (OR) = 0·16, P < 0·001] and more likely to be minimal residual disease‐positive (OR = 4·86, P = 0·01) but had similar OS after diagnosis and allo‐haematopoietic cell transplantation.

Therapy-induced Deletion in 11q23 Leading to Fusion of KMT2A With ARHGEF12 and Development of B Lineage Acute Lymphoplastic Leukemia in a Child Treated for Acute Myeloid Leukemia Caused by t(9;11)(p21;q23)/KMT2A-MLLT3

BACKGROUND/AIM

Fusion of histone-lysine N-methyltransferase 2A gene (KMT2A) with the Rho guanine nucleotide exchange factor 12 gene (ARHGEF12), both located in 11q23, was reported in some leukemic patients. We report a KMT2A-ARHGEF12 fusion occurring during treatment of a pediatric acute myeloid leukemia (AML) with topoisomerase II inhibitors leading to a secondary acute lymphoblastic leukemia (ALL).

MATERIALS AND METHODS

Multiple genetic analyses were performed on bone marrow cells of a girl initially diagnosed with AML.

RESULTS

At the time of diagnosis with AML, the t(9;11)(p21;q23)/KMT2A-MLLT3 genetic abnormality was found. After chemotherapy resulting in AML clinical remission, a 2 Mb deletion in 11q23 was found generating a KMT2A-ARHGEF12 fusion gene. When the patient later developed B lineage ALL, a t(14;19)(q32;q13), loss of one chromosome 9, and KMT2A-ARHGEF12 were detected.

CONCLUSION

The patient sequentially developed AML and ALL with three leukemia-specific genomic abnormalities in her bone marrow cells, two of which were KMT2A-rearrangements.