AB071. Predictive value of plasma microRNA-10b and microRNA-21 on chemotherapy toxicity, recurrence, and overall survival in high-grade glioma patients treated with temozolomide.

Background: The low level of median survival rate after complete therapy (i.e., surgery and concomitant chemotherapy and radiotherapy) in high-grade glioma (HGG) patients reflects the needs for a better understanding about HGG pathogenesis, including the role of epigenetic in glioma. MicroRNA (miRNA), a small chain non-coding RNA, has been increasingly utilized in the management of other oncology cases and might possess an immense potential in HGG. The expression of miRNA-10b and miRNA-21 (i.e., two miRNAs that are frequently studied due to its involvement in glioma) are higher in HGG patients and their role in regulatory mechanism of glioma has been established. However, the influence of those miRNAs in toxicity, recurrence, and overall survival of HGG patients is still unclear. We aim to assess the predictive value of plasma miRNA-10b and miRNA-21 in the chemotherapy toxicity, recurrence, and overall survival of HGG patients.

Methods: This is an observational analytic study using hospital-based mixed cohort approach. The study is conducted in RSUP Dr. Sardjito, Yogyakarta, from January 2021 to December 2024. We prospectively assess the plasma miRNA level from HGG patients who met the inclusive and exclusive criteria. The consecutive sampling is used until the sample size is met. Statistical analysis will be conducted for temozolomide toxicity using Spearman's rank correlation, for recurrence using logistical regression, and for overall survival test.

Results: In this ongoing study, we plan to collect samples from 155 HGG patients. As of April 2024, we managed to collect 96 samples (median age of 49 years and 55% of male patients). Most of the patients were diagnosed with World Health Organization (WHO) grade IV tumors (69.3%), with the most common diagnosis was glioblastoma (62%). Most of the patients had unmethylated O6-methylguanine-DNA methyltransferase (MGMT) and wild-type isocitrate dehydrogenase (IDH) status (62% and 57%, respectively). There was no difference in miRNA-21 expression based on MGMT status (methylated or unmethylated), nor IDH status (wild type or mutant), with P=0.39 and P=0.25, respectively. Moreover, we found no significant difference in miRNA-10b expression in both MGMT status and both IDH status (P=0.19 and P=0.09). As for the data regarding toxicity, recurrence, and overall survival was still on the process of data collection.

Conclusions: MiRNA is a promising epigenetic modulator that might be utilized in HGG management. A better understanding on the role of miRNA in HGG patients might be able to improve clinical outcome.