CLINIC PATHOLOGICAL AND MOLECULAR CORRELATION OF MICRORNA-21 EXPRESSION WITH TUMOR STAGE AND TREATMENT RESPONSE IN NON SMALL CELL LUNG CANCER

Abstract

Background: Non-small cell lung cancer (NSCLC) is a heterogeneous disease that has different biological characteristics and different responses to treatment. Molecular biomarkers can enhance the ability to better predict prognosis and identify patients who are more likely to be at risk of disease progression or therapeutic resistance. The oncogenic miR-21 is a microRNA associated with tumor proliferation, invasion, metastasis and resistance to anticancer drugs. Objective: To determine the clinicopathological and molecular correlation of miR-21 expression with tumor stage and treatment response in patients with non-small cell lung cancer. Methodology: This descriptive analytical study was conducted at Khyber Medical University and Khyber Teaching Hospital, Peshawar, from January 2025 to June 2025. Overall 56 patients with histopathologically proven NSCLC were included. Data on the demographic characteristics, histological subtype, level of tumour differentiation, TNM stage, lymph-node involvement, distant metastasis, and treatment response were recorded. The expression of miR-21 was measured by qRT-PCR and divided into low and high groups. Treatment response was determined as complete response, partial response, stable disease and progressive disease. The appropriate statistical tests were used, and a p value <0.05 was defined as being significant. Results: Mean miR-21 expression increased progressively from 1.82 ± 0.63 in stage I to 5.28 ± 1.37 in stage IV disease (p < 0.001). High miR-21 expression was significantly associated with advanced tumor stage, poor differentiation, lymph-node involvement, and distant metastasis. Objective treatment response was achieved in 64.0% of patients with low miR-21 expression compared with 29.0% of those with high expression (p = 0.009). miR-21 expression showed a significant positive correlation with tumor stage (r = 0.61, p < 0.001). High miR 21 expression was also independently associated with poor treatment response (OR = 3.74, 95% CI: 1.21–11.56, p = 0.022). Conclusion: Higher miR-21 expression was associated with advanced NSCLC, aggressive clinicopathological features, and reduced treatment response. miR-21 may have potential value as a prognostic and predictive molecular biomarker in NSCLC.