Kovalenko, Iuliia

Background: The global obesity epidemic has been well characterized over decades of research, linking increased body mass index (BMI) ≥ 25 to multiple medical conditions including increased cancer risk, morbidity, and mortality. The International Agency for Research on Cancer (IARC) group found a positive correlation between obesity to 13 cancers and multiple studies suggest leukemia should be added to this list. The causation behind this risk in leukemia however is not well understood and the prognostic factors have not been well characterized. Acute Myeloid Leukemia (AML) specifically defines risk based on cytogenetics between favorable, intermediate and unfavorable which significantly affects treatment decisions. The link between obesity and cytogenic risk factors in AML have not previously been thoroughly evaluated. To address this knowledge gap, we conducted a comprehensive meta-analysis aiming to evaluate the cytogenetic risk with obesity and prognostic significance in patients with AML. Methods: A systematic search was conducted across major databases until June 2023, using tailored search structures, subject headings, and keywords developed in collaboration with a medical research librarian. Two investigators independently screened the studies for inclusion. The inclusion criteria encompassed retrospective and prospective clinical studies that reported on the association between established cytogenetic classifications and standardized measures of excessive weight (BMI 25-30) and obesity (BMI ≥ 30). Meta-analysis was conducted using restricted maximum likelihood random-effects model. Results: From an initial pool of 1673 identified studies, eleven studies met the inclusion criteria, encompassing a total of 5887 patients. Among these patients, 1363 met the criteria for obesity (BMI ≥ 30) and 2176 met the criteria for excessive weight (BMI 25-30). The median patient's age was 54 (ranging from 15 to 89). The included studies originated from diverse geographic regions, including the USA, Japan, and France. Baseline patient characteristics are summarized in Table 1. Compared to overweight patients, our meta-analysis revealed a significant association between obesity and higher odds of unfavorable/intermediate cytogenetic risk (odds ratio [OR] 1.27, 95% CI [1.04; 1.54]), as seen in Figure 1. However, no meaningful statistical inference could be made regarding the association between obesity and specific gene mutations (such as FLT3, NPM1, CEBPa, TET2, IDH1, IDH2, RUNX1, and KRAS) due to the limited number of studies and small number of patients involved. Conclusion: Our meta-analysis demonstrates a significant association between obesity and unfavorable/ intermediate cytogenetic risk in patients with AML. Although the precise biological mechanisms remain elusive, several potential explanations have been proposed. These include the impact of obesity leading to chronic low-grade inflammation, altered adipokine secretion and insulin resistance, and metabolic changes on leukemic cell growth and survival. Despite the limitations of unknown cytogenetic risk in 590 patients and limited mutation data in some studies, our findings suggest that obesity may impact the prognosis of AML. Future research should address these limitations and provide a more comprehensive understanding of the intricate interplay between obesity, cytogenetics, and AML prognosis.

Introduction Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma. The mainstay of frontline therapy remains R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) or R-CHOP-like immunochemotherapy. Patients' responses to R-CHOP therapy vary depending on the stage and/or molecular subtypes of DLBCL. Approximately 40% of advanced-stage DLBCL patients suffer from a refractory or relapsed disease[1]. The outcome for patients with early relapses after rituximab-containing first-line therapy remains poor[2]. DLBCL poses a marked degree of genetic heterogeneity. Here, we compare the expression of genes related to epigenetics and chromatin modifications in DLBCL patients resistant and non-resistant to R-CHOP therapy. Objective The aim of this study is to assess the differences in the expression of genes related to epigenetics and chromatin modification in DLBCL patients that could lead to chemoresistance and failure of R-CHOP treatment. Method The gene expression profile (GEP) was obtained from Gene Expression Omnibus (GEO) database (Accession number: GSE173263) submitted by Dlouhy et al[3]. The GEP was analyzed in DLBCL cases, including 10 early failure cases (defined as refractory to induction treatment or early relapsing (<12 months from diagnosis)) and 29 responding patients, to identify features associated to primary chemoresistance. The comparison was done using the list of genes proposed by Bakhshi, T. et. al[4] , where he selected the genes that were identified to potentially cause epigenetic and chromatin modifications in DLCBL. All the comparisons were done using a T-test. Results There were significant differences in the gene expression related to epigenetics and chromatin modifications between DLBCL patients in the early failure arm versus the remission arm. Patients who had early failure to R-CHOP tended to have higher expression of these genes: SMARCA4 (p=0.010), SETD1B (p=0.018), SETD2 (p=0.024), EP300 (p=0.012), MLL3 (p=0.049), INO80 (p=0.001), CHD8 (p=0.007), NCOR1 (p=0.020), ARID1B (p=0.034), and SETD5 (p=0.007). Compared to the patients who were in remission after R-CHOP therapy, these patients had significantly higher expression of HIST1H1E (p=0.007). Conclusion Gene expression related to epigenetics and chromatin modifications significantly impacts the prognosis of DLBCL patients treated with R-CHOP. Differences in gene expression may lead to chemoresistance, and higher expression levels are associated with a worse prognosis. This study sheds light on the importance of chromatin and epigenetic modifications in DLBCL progression, guiding the development of future therapies.