Prognostic Values of MicroRNA-21 and Ki-67 in Diffuse Large B-Cell Lymphoma Patients: Egyptian Experience.

BACKGROUND: MicroRNA-21 (miR-21) is a small non-coding RNA which influences tumorigenesis by inhibiting the expression of target genes. Ki-67 is a nucleolar antigen highly correlated with the rate of proliferating cells. In this study, we aimed to evaluate the prognostic impact of miR-21 and Ki-67 in DLBCL disease in a cohort of Egyptian patients. METHODS: We prospectively enrolled 53 newly diagnosed DLBCL patients. RT-PCR was used to evaluate the plasma expression levels of miR-21. Tissue Ki-67 was assessed using immunohistochemistry (IHC) of lymph node biopsy sections. Overall survival (OS) and progression free survival (PFS) were the primary outcomes. RESULTS: miR-21 expression was significantly higher in patients with DLBCL in comparison to controls (p < 0.001). The median Ki-67 expression was 70% and positivity ranged from 25% to 100%. Response to treatment was achieved in 23 patients (43.4%). Higher miR-21 was associated with poor response to treatment (p = 0.03). Although patients' age was a significant predictor of OS in univariate analysis, none of the studied factors could predict OS in multivariate analysis. However, we found that Ki-67 expression was a significant predictor of PFS in both univariate and multivariate analyses. CONCLUSIONS: The study suggested that plasma miR-21 might be a valuable non-invasive prognostic marker of response to treatment in DLBCL patients. Moreover, Ki-67 is a potential significant predictor of both OS and PFS in those patients.

Histone H3K27M Mutation Overrides Histological Grading in Pediatric Gliomas.

Pediatric high-grade gliomas (HGG) are rare aggressive tumors that present a prognostic and therapeutic challenge. Diffuse midline glioma, H3K27M-mutant is a new entity introduced to HGG in the latest WHO classification. In this study we evaluated the presence of H3K27M mutation in 105 tumor samples histologically classified into low-grade gliomas (LGG) (n = 45), and HGG (n = 60). Samples were screened for the mutation in histone H3.3 and H3.1 variants to examine its prevalence, prognostic impact, and assess its potential clinical value in limited resource settings. H3K27M mutation was detected in 28 of 105 (26.7%) samples, and its distribution was significantly associated with midline locations (p-value < 0.0001) and HGG (p-value = 0.003). Overall and event- free survival (OS and EFS, respectively) of patients with mutant tumors did not differ significantly, neither according to histologic grade (OS p-value = 0.736, EFS p-value = 0.75) nor across anatomical sites (OS p-value = 0.068, EFS p-value = 0.153). Detection of H3K27M mutation in pediatric gliomas provides more precise risk stratification compared to traditional histopathological techniques. Hence, mutation detection should be pursued in all pediatric gliomas. Meanwhile, focusing on midline LGG can be an alternative in lower-middle-income countries to maximally optimize patients' treatment options.