Somatic mutations predict prognosis in myelodysplastic syndrome patients with normal karyotypes

Recent advances in the role of atypical cadherin FAT1 in tumorigenesis (Review)

The FAT atypical cadherin 1 (FAT1) gene is the ortholog of the Drosophila fat gene and encodes the protocadherin FAT1. FAT1 belongs to the cadherin superfamily, a group of full-length membrane proteins that contain cadherin-like repeats. In various types of human cancer, FAT1 is one of the most commonly mutated genes, and is considered to be an emerging cancer biomarker and a potential target for novel therapies. However, the biological functions of FAT1 and the precise downstream signaling pathways that it mediates have remained to be fully elucidated. The present review discussed the current literature on FAT1, focusing on FAT1 mutations and expression levels, and their impact on signaling pathways and mechanisms in various types of cancer, including both solid tumors and hematological malignancies, such as esophageal squamous cell carcinoma, head and neck squamous cell carcinoma, lung squamous cell carcinoma, hepatocellular carcinoma, glioma, breast cancer, acute lymphoblastic leukemia, acute myeloid leukemia, lymphoma and myeloma. The present review aimed to provide further insights and research directions for future studies on FAT1 as an oncogenic factor or tumor suppressor.

Latest Insights and Therapeutic Advances in Myelodysplastic Neoplasms

Myelodysplastic syndromes/neoplasms (MDSs) encompass a range of hematopoietic malignancies, commonly affecting elderly individuals. Molecular alterations in the hematopoietic stem cell compartment drive disease pathogenesis. Recent advancements in genomic profiling have provided valuable insights into the biological underpinnings of MDSs and have expanded therapeutic options, particularly for specific molecularly defined subgroups. This review highlights the diagnostic principles, classification updates, prognostic stratification systems, and novel treatments, which could inform future clinical trials and enhance the management of adult MDS patients, particularly for specific molecularly defined subgroups.

Association between Leukemic Evolution and Uncommon Chromosomal Alterations in Pediatric Myelodysplastic Syndrome

Background

Pediatric myelodysplastic syndrome (pMDS) is a group of rare clonal neoplasms with a difficult diagnosis and risk of progression to acute myeloid leukemia (AML). The early stratification in risk groups is essential to choose the treatment and indication for allogeneic hematopoietic stem cell transplantation (HSCT). According to the Revised International Prognostic Scoring System, cytogenetic analysis has demonstrated an essential role in diagnosis and prognosis. In pMDS, abnormal karyotypes are present in 30-50% of the cases. Monosomy 7 is the most common chromosomal alteration associated with poor prognosis. However, the rarity of specific cytogenetic alterations makes its prognosis uncertain. Thus, this study aimed to describe uncommon cytogenetic alterations in a cohort of 200 pMDS patients and their association with evolution to AML.

Methods

The cytogenetic analysis was performed in 200 pMDS patients by G-banding and fluorescence in situ hybridization between 2000 to 2022.

Results

Rare chromosome alterations were observed in 7.5% (15/200) of the cases. These chromosome alterations were divided into four cytogenetic groups: hyperdiploidy, biclonal chromosomal alterations, translocations, and uncommon deletions representing 33.3%, 33.3%, 20%, and 13.3%, respectively. Most of these patients (10/15) were classified with advanced MDS (MDS-EB and MDS/AML) and the initial subtype was present in five patients (RCC). The leukemic evolution was observed in 66.66% (10/15) of the patients. Most patients had poor clinical outcomes and they were indicated for HSCT.

Conclusion

The study of uncommon cytogenetic alterations in pMDS is important to improve the prognosis and guide early indication of HSCT.

Impact of IPSS-M implementation in real-life clinical practice

Objectives

The IPSS-M is a recently published score for risk stratification in myelodysplastic syndromes (MDS), based on clinical and molecular data. We aimed to evaluate its relevance on treatment choice in a real-life setting.

Methods

We retrospectively collected clinical, cytogenetic and molecular data from 166 MDS patients. We calculated IPSS-R and IPSS-M scores and compared Overall Survival (OS) and Leukemia Free Survival (LFS). We also analyzed which patients would have been affected by the re-stratification in terms of clinical management.

Results

We found that 86.1% of the patients had at least one genetic alteration. The most frequent mutated genes were SF3B1 (25.9%), DNMT3A (16.8%) and ASXL1 (14.4%). IPSS-M re-stratified 48.2% of the patients, of which 16.9% were downgraded and 31.3% were upgraded. IPSS-M improved outcome prediction, with a Harrell's c-index of 0.680 vs 0.626 for OS and 0.801 vs 0.757 for LFS. In 22.2% of the cohort, the reclassification of the IPSS-M could potentially affect clinical management; 17.4% of the patients would be eligible for treatment intensification and 4.8% for treatment reduction.

Conclusions

IPSS-M implementation in clinical practice could imply different treatment approaches in a significant number of patients. Our work validates IPSS-M in an external cohort and confirms its applicability in a real-life setting.

The effect of granulocyte-colony stimulating factor, decitabine, and busulfan-cyclophosphamide versus busulfan-cyclophosphamide conditioning on relapse in patients with myelodysplastic syndrome or secondary acute myeloid leukaemia evolving from myelodysplastic syndrome undergoing allogeneic haematopoietic stem-cell transplantation: an open-label, multicentre, randomised, phase 3 trial

BACKGROUND

Relapse remains high in patients with myelodysplastic syndrome-refractory anaemia with excess blasts (RAEB) or secondary acute myeloid leukaemia evolving from myelodysplastic syndrome undergoing allogeneic haematopoietic stem-cell transplantation (HSCT). We aimed to investigate whether granulocyte-colony stimulating factor (G-CSF) and decitabine plus busulfan-cyclophosphamide conditioning reduced relapse compared with busulfan-cyclophosphamide in this population.

METHODS

We did an open-label, randomised, phase 3 trial at six hospitals in China. Eligible patients (aged 14-65 years) had myelodysplastic syndrome-RAEB or secondary acute myeloid leukaemia evolving from myelodysplastic syndrome, and an Eastern Cooperative Oncology Group performance status of 0-2 and HSCT comorbidity index of 0-2. Patients were randomly assigned (1:1) to receive G-CSF, decitabine, and busulfan-cyclophosphamide conditioning or busulfan-cyclophosphamide conditioning. Randomisation was done with permuted blocks (block size four) with no stratification and was implemented through an interactive web-based response system, which was independent of study site staff and investigators. G-CSF, decitabine, and busulfan-cyclophosphamide conditioning comprised G-CSF 5 μg/kg daily subcutaneously (days -17 to -10), decitabine 20 mg/m² daily intravenously (days -14 to -10), busulfan 3·2 mg/kg daily intravenously (days -7 to -4), and cyclophosphamide 60 mg/kg daily intravenously (days -3 and -2). Busulfan-cyclophosphamide conditioning comprised the same dose and duration of busulfan and cyclophosphamide. The primary endpoint was 2 year cumulative incidence of relapse. All efficacy and safety endpoints were assessed in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02744742; the trial is complete.

FINDINGS

Between April 18, 2016, and Sept 30, 2019, 297 patients were screened for eligibility, 202 of whom were randomly assigned to G-CSF, decitabine, and busulfan-cyclophosphamide (n=101) or busulfan-cyclophosphamide (n=101) conditioning. 123 (61%) participants were male and 79 (31%) were female. Median follow-up was 32·4 months (IQR 10·0-43·0). The 2-year cumulative incidence of relapse was 10·9% (95% CI 5·8-17·9) in the G-CSF, decitabine, and busulfan-cyclophosphamide group and 24·8% (16·8-33·5) in the busulfan-cyclophosphamide group (hazard ratio 0·39 [95% CI 0·19-0·79]; p=0·011). Within 100 days after transplantation, the most common grade 3-4 adverse events in the G-CSF, decitabine, and busulfan-cyclophosphamide group and the busulfan-cyclophosphamide group were infections (34 [34%] and 32 [32%]), acute graft-versus-host disease (30 [30%] and 30 [30%]), and gastrointestinal toxicity (28 [28%] and 29 [29%]). 11 (11%) patients in the G-CSF, decitabine, and busulfan-cyclophosphamide group and 13 (13%) in the busulfan-cyclophosphamide group died of adverse events. There were no treatment related deaths.

INTERPRETATION

Our results suggest that G-CSF, decitabine, and busulfan-cyclophosphamide conditioning is a better choice than busulfan-cyclophosphamide conditioning for patients with myelodysplastic syndrome-RAEB or secondary acute myeloid leukaemia evolving from myelodysplastic syndrome undergoing allogeneic HSCT. This conditioning could be a suitable therapuetic option for this patient population.

FUNDING

None.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.