Role of circulating microRNAs in non-small cell lung carcinoma.

INTRODUCTION: Non-small cell lung cancer (NSCLC) is the leading cause of mortality globally. Early imaging detection modalities are associated with high false-positive rates and radiation exposure. A non-invasive biomarker can serve as an improvised method for early detection. MicroRNAs can serve as a potential non-invasive biomarker as they are stable in circulation, tissue or biological process-specific, easy to detect, cost-effective, and not associated with radiation hazards. This study validates circulating microRNA in NSCLC of the Indian population and studies its correlation with clinicopathological parameters.

MATERIALS AND METHODS: Circulating microRNA (-miR-193b, miR-301a, miR-7, and miR-25) was evaluated in 101 cases of tissue-proven NSCLC and 28 controls in serum samples.

RESULTS: There were 67 male and 34 female patients (Male: Female = 1.97:1). The age range was 25 to 86 years with a median age of 60 years. There was a significant upregulation in the expression of miR-193b in the NSCLC group as compared to controls (P = 0.034). MiR-7 was also upregulated while miR-25 and miR-301a were downregulated in NSCLC as compared to controls; however, a level of significance was not achieved. ROC curve analysis for miR-193b showed an AUC of 0.636 (95% CI, 0.522-0.750; P-value = 0.036) between NSCLC cases and controls.

CONCLUSION: The present study showed variable expression of the above-studied miRNAs. MiR-193b showed a significant upregulation in cancer patients; however, the other three miRNAs were not conclusive. This suggests that profiling of microRNA in each population is essential to search for a valid non-invasive biomarker in that population.