Matching plasma and tissue miRNA expression analysis to detect viable ovarian germ cell tumors.

Abstract

MicroRNAs (miRNAs) are emerging as circulating biomarkers in germ cell tumors (GCT) with potential to guide management. Their role and expression patterns are more established in testicular GCTs, while lesser data exist in ovarian GCTs (OGCT). Patients diagnosed with OGCT with plasma and tumor tissue available in our provincial biobank were included. Total RNA was extracted, and RT-qPCR was performed to measure miR-371-3 and miR-302/367 levels. Healthy plasma and ovarian tissue served as controls. Statistical analyses were performed using ANOVA and the Mann-Whitney U test. Clinicopathologic data was collected by chart review. From 2007 to 2022, 23 patients with OGCT were identified: 13 with viable non-teratoma germ cell (VNTGC) and 10 with immature teratoma germ cell (ITGC) tumors. Compared to healthy controls, all patients with VNTGC but not ITGC tumors had significantly higher miRNA levels in preoperative plasma and tumor tissue. Plasma miRNA kinetics correlated with disease burden, decreasing to undetectable levels following treatment, and increasing significantly upon relapse. MiR-371-3 and miR-302/367 are highly expressed in ovarian VNTGC but not ITGC tumors, and their plasma levels correlate with disease burden. Future studies validating these findings in a larger cohort are needed to develop miRNAs as circulating biomarkers for clinical use.