Role of circulating miR-30a-5p and miR-93-5p as liquid biopsy biomarkers for prediction of prognosis in metastatic non-small cell lung cancer.

e20529 Background: Advanced non-small cell lung cancer (NSCLC) carries a poor prognosis, and reliable non-invasive biomarkers for prognostication remain limited. Circulating microRNAs (miRNAs), such as miR-30a-5p and miR-93-5p, have shown potential in reflecting tumour behaviour, miR-93-5p is often oncogenic, while miR-30a-5p functions as a tumor suppressor. This study aims to evaluate the prognostic value of circulating miR-30a-5p and miR-93-5p in patients with advanced NSCLC. Methods: In this mixed design study with its first part cross sectional and second part prospective cohort study, 60 patients with histologically confirmed advanced NSCLC and 30 healthy controls were enrolled. Serum levels of miR-30a-5p and miR-93-5p were measured using quantitative real-time PCR at diagnosis and after four cycles of platinum-based chemotherapy. Expression patterns were correlated with clinical and pathological parameters. Results: At diagnosis, miR-30a-5p was downregulated in 73.3% and upregulated in 26.7%, while miR-93-5p was downregulated in 60.0% and upregulated in 40.0%. After chemotherapy, downregulation persisted in 85.4% for miR-30a-5p and 54.2% for miR-93-5p. A significant association was found between miR-30a-5p upregulated expression and bone metastasis (p = 0.041). while miR-93-5p showed significant association with its upregulation and lymph node metastasis (p = 0.021). Also, significant association between miR-93-5P upregulation and poor therapeutic response, with higher expression levels predominantly observed in non-responsive patients (P=0.003). Kaplan-Meier survival analysis revealed that up-regulation of serum miRNA-30a-5p and miRNA-93-5p was significantly correlated with poorer patient survival (P=0.002 for both). On multivariate analysis, using Cox’s regression; the only independent factor that significantly affected the overall survival was miRNA-30a-5p with HR 4.1. Conclusions: miR-30a-5p and miR-93-5p shows promise as a prognostic biomarker particularly for predicting bone and lymph node involvement, predict treatment response and overall survival in advanced NSCLC. The persistent downregulation of both miRNAs supports their utility in disease monitoring.