Circulating miR-23b-3p, miR-30e-3p, and miR-205-5p as Novel Predictive Biomarkers for Ramucirumab-Paclitaxel Therapy Outcomes in Advanced Gastric Cancer.

Angiogenesis inhibition treatments are limited and are often too late for advanced gastric cancer (GC) patients, in whom its efficacy is reduced. New molecular biomarkers are needed to optimize therapy regimens. In regard to this framework, circulating miRNAs, with high sensitivity and specificity, could be useful biomarkers of GC. The present longitudinal study was focused on analyzing the expression levels of a blood miRNA signature in a cohort of 40 patients receiving second-line therapy combining Ramucirumab and Paclitaxel, stratified based on their Progression-Free Survival (PFS). Using differential and bioinformatic analysis, miR-205-5p, miR-30e-3p, and miR-23b-3p were selected as possible predictive biomarkers, with the results showing that they were more highly expressed in patients exhibiting longer PFS and that they were involved in modulating angiogenesis. Furthermore, patients with longer PFS showed a progressive and significant decrease in the selected miRNA to minimal levels. The loss of the protective effect and the increased expression of the hypothetical targets, including angiopoietin-2, were then observed. The hypothesis was supported by the inverse correlation found for miR-205-5p and angiopoietin-2. Circulating levels of miR-205-5p were protective (HR = 0.37, = 0.02) and patients with higher baseline miRNA levels had longer OS (12.47 vs. 9.00 months). Our findings suggest that these three miRNAs may be novel candidates as non-invasive predictive markers of therapy outcomes.