Non-Small Cell Lung Cancer: Targetable Variants in Concurrent Tissue and Liquid Biopsy Testing in a North Indian Cohort

Paturu, Radha; Lingaiah, Raghavendra; Kumari, Niraj; Singh, Shalini; Krishnani, Narendra; Srivastava, Shreya; Siddiqui, Saima Haleem; Nath, Alok

doi:10.31557/APJCP.2023.24.10.3467

Non-Small Cell Lung Cancer: Targetable Variants in Concurrent Tissue and Liquid Biopsy Testing in a North Indian Cohort

Document Type : Research Articles

Authors

¹ Department of Pathology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

² Department of Pathology & Lab Medicine, AIIMS Raebareli, Raebareli, Uttar Pradesh, India.

³ Department of Radiotherapy, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

⁴ Department of Pulmonary Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.

10.31557/APJCP.2023.24.10.3467

Abstract

Objectives: Testing for EGFR, ALK, ROS1 and MET alterations in paired tissue and plasma samples of treatment-naïve patients of NSCLC and correlating their status with overall survival. Materials and methods: One hundred treatment-naïve patients were recruited after obtaining informed consent. Ten ml of blood was collected within a period of two weeks from histological diagnosis, prior to the start of any treatment. DNA & RNA extraction was done from formalin-fixed paraffin embedded (FFPE) tissue and total cell-free nucleic acid extraction was done from plasma samples. EGFR mutation, ALK, ROS1 and MET rearrangements were tested by ARMS (Amplification Refractory Mutation System) PCR. All statistical analyses were conducted in R version 4.1.1. Results: A total of 61 cases showed molecular alterations in tissue samples which included EGFR mutations (47), ALK rearrangements (12), ROS1 fusion (2). MET alteration was not detected. Forty-three cases showed EGFR mutations in plasma, 26 of which were concurrently positive in tissue. Concordance observed was 62%. ALK-EML4 rearrangement, ROS1 fusion and MET were not detected in plasma samples. Sensitivity and specificity for detection of EGFR mutation in plasma were 55.3% and 67.9% respectively. Univariate Cox regression analysis showed a positive association between EGFR mutation in tissue and overall survival (HR = 0.4; 95% CI: 0.2-0.7; p = 0.003) and improved overall survival in those who received targeted therapy (HR = 0.29; 95% CI: 0.1–0.8; p = 0.02). Conclusion: Concurrent testing in tissue and liquid biopsy in NSCLC increased the detection of EGFR mutations (47% to 64%). This has substantial implications in deciding treatment and administration targeted therapy and the consequent overall survival.

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