Assessing the efficacy of allogeneic hematopoietic stem cells transplantation (allo-HSCT) by analyzing survival end points in defined groups of acute myeloid leukemia patients: a retrospective, multicenter Polish Adult Leukemia Group study

The 17‐gene stemness score associates with relapse risk and long‐term outcomes following allogeneic haematopoietic cell transplantation in acute myeloid leukaemia

A 17‐gene stemness (LSC17) score determines risk in acute myeloid leukaemia patients treated with standard chemotherapy regimens. The present study further analysed the impact of the LSC17 score at diagnosis on outcomes following allogeneic haematopoietic cell transplantation (HCT). Out of 452 patients with available LSC17 score, 123 patients received allogeneic HCT. Transplant outcomes, including overall (OS), leukaemia‐free survival (LFS), relapse incidence (RI) and non‐relapse mortality (NRM), were compared according to the LSC17 scored group. The patients with a low LSC17 score had higher OS (56.2%) and LFS (54.4%) at 2 years compared to patients with high LSC17 score (47.2%, p = 0.0237 for OS and 46.0%, p = 0.0181 for LFS). The low LSC17 score group also had a lower relapse rate at 2 years (12.7%) compared to 25.3% in the high LSC17 score group (p = 0.017), but no difference in NRM (p = 0.674). Worse outcomes in the high LSC17 score group for OS, LFS and relapse were consistently observed across all stratified sub‐groups. The use of more intensive conditioning did not improve outcomes for either group. In contrast, chronic graft‐versus‐host‐disease was associated with more favourable outcomes in both groups. The 17‐gene stemness score is highly prognostic for survival and relapse risk following allogeneic HCT.

Influence of FLT3-ITD and NPM1 status on allogeneic hematopoietic cell transplant outcomes in patients with cytogenetically normal AML

OBJECTIVE

In individuals with cytogenetically normal (CN) AML, disease risk is estimated using molecular features such as the status of NPM1 and FLT3-ITD genes. However, data regarding the impact of NPM1 and FLT3-ITD status on hematopoietic stem cell transplant (HCT) outcomes are limited. We examined the effect of NPM1 and FLT3-ITD status on transplant outcomes in 131 CN AML patients transplanted at Princess Margaret Hospital between 2006 and 2017.

METHODS

Overall survival (OS) was calculated using Kaplan-Meier analysis and multivariable Cox proportional hazards regression. Cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) were calculated using competing risk regression.

RESULTS

There was no difference in 3-year OS among NPM1⁺ /FLT3-ITD^- , NPM1^- /FLT3-ITD^- , NPM1⁺ /FLT3-ITD⁺ and NPM1^- /FLT3-ITD⁺ patients: 56% (95% CI, 29%-76%), 61% (95% CI, 46%-73%), 53% (95% CI, 34%-70%) and 52% (95% CI, 17%-78%), respectively. CIR at 3-years was similar among NPM1^- /FLT3-ITD^- , NPM1⁺ /FLT3-ITD⁺ and NPM1^- /FLT3-ITD⁺ patients-14% (95% CI, 6%-26%), 13% (95% CI, 4%-28%) and 19% (95% CI, 4%-41%), respectively-while there were no relapses in the NPM1⁺ /FLT3-ITD^- group. NRM at 3 years for NPM1⁺ /FLT3-ITD^- , NPM1^- /FLT3-ITD^- , NPM1⁺ /FLT3-ITD⁺ and NPM1^- /FLT3-ITD⁺ patients was similar at 44% (95% CI, 19%-67%), 38% (95% CI, 25%-50%), 43% (95% CI, 25%-59%) and 44% (95% CI, 14%-71%), respectively.

CONCLUSION

NPM1 and FLT3-ITD status may provide limited prognostic information about transplant outcomes in CN AML patients.

Impact of Allogeneic Stem Cell Transplantation in First Complete Remission in Acute Myeloid Leukemia: A National Population-Based Cohort Study

To examine the outcomes of allogeneic stem cell transplantation (HSCT) in first complete remission (CR1) compared with chemotherapy alone in a population-based setting, we identified a cohort of patients with acute myeloid leukemia (AML) aged 15 to 70 years diagnosed between 2000 and 2014 in Denmark. Using the Danish National Acute Leukemia Registry, we compared relapse risk, relapse-free survival (RFS), and overall survival (OS) between patients with unfavorable cytogenetic features receiving postremission therapy with conventional chemotherapy only versus those undergoing HSCT in CR1. To minimize immortal time bias, we performed Cox proportional hazards regression, included date of allogeneic HSCT as a time-dependent covariate, and stratified the results by age (<60 or ≥60 years) and cytogenetic risk group. Overall, 1031 patients achieved a CR1. Of these, 196 patients (19%) underwent HSCT. HSCT was associated with a lower relapse rate (24% versus 49%) despite a similar median time to relapse (287 days versus 265 days). In all subgroups, the risk of relapse was lower and both RFS and OS were superior in recipients of HSCT (OS, adjusted mortality ratios: all patients, .54 [95% confidence interval (CI), .42-.71]; patients age <60 years, .58 [95% CI, .42-.81]; patients age ≥60 years, .42 [95% CI, .26-.69]; patients with intermediate-risk cytogenetics, .63 [95% CI, .43-.87]; patients with adverse-risk cytogenetics, .40 [95% CI, .24-.67]). In conclusion, in this population-based nationwide cohort study, HSCT was associated with improved survival in both younger and older patients and in patients with both intermediate and adverse cytogenetic risk.

Myeloid-derived suppressor cells as effectors of immune suppression in cancer

The tumor microenvironment consists of an immunosuppressive niche created by the complex interactions between cancer cells and surrounding stromal cells. A critical component of this environment are myeloid-derived suppressor cells (MDSCs), a heterogeneous group of immature myeloid cells arrested at different stages of differentiation and expanded in response to a variety of tumor factors. MDSCs exert diverse effects in modulating the interactions between immune effector cells and the malignant cells. An increased presence of MDSCs is associated with tumor progression, poorer outcomes, and decreased effectiveness of immunotherapeutic strategies. In this article, we will review our current understanding of the mechanisms that underlie MDSC expansion and their immune-suppressive function. Finally, we review the preclinical studies and clinical trials that have attempted to target MDSCs, in order to improve responses to cancer therapies.