Prognostic Value of ATRX and p53 Status in High-Grade Glioma Patients in Morocco

INTRODUCTION

Glioblastoma and astrocytoma, grade 4, are the most common and aggressive brain tumors. Several biomarkers, such as the isocitrate dehydrogenase mutation (IDH-1), alpha-thalassemia/mental retardation, and the X-linked mutation (ATRX), enable more accurate glioma classification and facilitate patient management. This study aimed to determine the prognostic value of clinical and molecular factors (IDH, TP53, and ATRX mutations). We also studied the relationship between these molecular markers and the overall survival (OS) of 126 patients with grade 4 glioblastoma/astrocytoma.

METHODS

The immunohistochemical study was conducted using antibodies namely, IDH1, R132H, p53, and ATRX. Statistical tests were used to investigate factors that might influence overall survival using IBM SPSS Statistics, version 25.0 (IBM Corp., Armonk, NY).

RESULTS

The median age at diagnosis was 51.5 years. Patients with a Karnofsky performance score (KPS) <70 presented less favorable survival outcomes compared to those with a KPS ≥70. The median OS for patients was found to be 11.17 months. Expression of IDH1 R132H was found in 13.5% of patients, p53 overexpression was identified in 55.6% of cases, and loss of ATRX expression was detected in 11.9%. The group of patients with IDH mutant/ATRX mutant/p53 wild-type had the best prognosis (OS = 27.393 months; p = 0.015). Our results were in line with previous studies.

CONCLUSION

The clinical value of IDH and ATRX mutations in prognostic assessment was confirmed (p ≤0.05). The overexpression of p53 had no significant impact on OS (p = 0.726). Therefore, p53 alone cannot predict survival in glioblastoma patients. Based on the results, these biomarkers may be a potential therapeutic target to prolong patient survival, hence the need for further investigations.

Microsatellite Instability Analysis in Gastric Carcinomas of Moroccan Patients

Aim: To investigate correlations between microsatellite instability (MSI) and the phenotype, clinicopathological features, and overall survival (OS) in Moroccan gastric cancer (GC) patients. We evaluated the mutation frequency of 22 MSI-target genes in MSI-positive tumors. Materials and Methods: MSI evaluation were performed for 97 gastric tumors by multiplex polymerase chain reaction (PCR) using a panel of five quasimonomorphic mononucleotide repeat markers (NR27, NR21, NR24, BAT25, and BAT26). The mutation profiles of 22 MSI-target genes were assessed by multiplex PCR and genotyping. Kaplan-Meier curves, the log-rank test, and the Cox proportional hazard regression model were used to conduct survival analyses. Results: Microsatellite stable (MSS) status was observed in 77/97 (79.4%) gastric cancer samples, MSI-Low in 7 (7.2%) samples, and MSI-High (MSI-H) in 13 (13.4%) cases. The MSI-H phenotype was significantly associated with older age (p = 0.004), tumor location (p < 0.001), and intestinal-type of Lauren classification (p < 0.001). Among the 22 MSI target genes analyzed, the most frequently altered genes were HSP110 (84.6%), EGFR (30.8%), BRCA2 (23.1%), MRE11 (23.1%), and MSH3 (23.1%). Multivariate analysis revealed the MSS phenotype (Hazard ratio, 0.23; 95% confidence interval, 0.7-7.4; p = 0.014) as an independent indicator of poor prognosis in our population. Conclusions: This study is the first analysis of MSI in Moroccan GC patients. MSI-H GCs have distinct clinicopathological features and an improved OS. We have identified candidate target genes altered in MSI-positive tumors with potential clinical implications. These findings can guide immunotherapy designed for Moroccan GC patients.