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

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.

Allogeneic hematopoietic stem cell transplantation in patients with therapy-related hematologic malignancies developing after multiple myeloma

INTRODUCTION

Increasing survival of patients with multiple myeloma (MM) has resulted in an increased recognition of therapy-related hematological malignancies (t-MDS/AML, t-ALL, and t-CMML). There are limited data on the role of allogeneic hematopoietic stem cell transplantation (HCT) in this patient population.

PATIENTS AND METHODS

We retrospectively reviewed patients who underwent HCT for t-MDS/AML, t-ALL, and t-CMML developing after receiving treatment for MM at our center. Patients were analyzed for myeloma characteristics and therapy, time to diagnosis of therapy-related hematological neoplasms, clinical, laboratory characteristics, transplant details, relapse-free survival (RFS), and overall survival (OS).

RESULTS

Twenty patients underwent HCT for therapy-related hematological malignancies after MM (t-MDS/AML = 13, t-ALL = 6, t-CMML = 1). Median(range) age at time of transplant was 62.5 (49-73) years and 70% (n = 14) were male. The most common cytogenetic abnormality was complex/monosomal karyotype in 30% (n = 6) followed by monosomy/deletion of chromosome 5 or 7 in 15% (n = 3) of patients each. Donors were human leukocyte antigen matched (10/10 or 6/6) siblings in 30% (n = 6), unrelated in 60% (n = 12) and haploidentical in 10% (n = 2) patients. Estimated 2-year OS and RFS for the whole cohort were 53.1% and 47.2% respectively. There was a trend toward better survival in patients with t-ALL when compared to t-MDS/AML; however, the difference was not statistically significant. We did not find any pre-transplant or post-transplant factors that were predictive of survival outcomes after multivariate analysis.

CONCLUSIONS

Allogeneic HCT provides substantial long-term disease-free survival in a proportion of patients with MM-associated therapy-related hematological malignancies. Multicenter studies with more patients and longer follow-up may provide additional information about factors affecting outcomes.

Allogeneic Hematopoietic Stem Cell Transplantation in Therapy Related Acute Leukemia

Therapy related acute leukemia consists of a unique subset of acute leukemia with an increased frequency of high risk cytogenetic and molecular abnormalities, dismal response to therapy, higher relapse rates and poor overall survival. Therapy related acute myeloid leukemia (t-AML) is a better defined disease entity than therapy related acute lymphoid leukemia (t-ALL). However, in recent times, t-ALL is also being increasingly recognized and extensively studied. Therapy related acute myeloid leukemia is usually classified together with therapy related myelodysplastic syndrome. However, the management of these two diseases maybe different regarding needs of induction chemotherapy and eligibility for upfront allogeneic hematopoietic stem cell transplantation (Allo HSCT). There is also evidence regarding differences in prognosis and outcomes between these two entities. Allo HSCT offers a potential for cure in t-AML and t-ALL. However, existing literature on the same is confounded by inclusion of t-MDS and secondary acute leukemias. Here we review the current evidence on the outcomes and predictors of outcomes of Allo HSCT in the management of therapy related acute leukemias. We also shed light into the under-representation of therapy related leukemias in clinical trials. This stresses the need for prospective trials incorporating measurable residual disease monitoring and sequential next generation sequencing based genomic data for accurate prognostication and management of therapy related acute leukemia.