Abstract
Lung cancer remains a leading cause of cancer mortality in India, yet its genomic landscape remains understudied. To address this gap, we performed whole-exome sequencing (WES) on tumor and matched blood samples from 47 lung cancer patients [adenocarcinoma (ADC): 30; squamous cell carcinoma (SqCC): 10; and small cell lung cancer (SCLC): 7] to comprehensively analyze somatic mutations across all protein-coding genes. Our analysis revealed novel and recurrent alterations, with MUC4 being the most recurrently mutated gene, and TP53 emerging as the most frequently mutated across subtypes. Shared mutations included MUC4, MUC16, TP53, KMT2C, CDC27, and UBXN11, the latter not previously associated with lung cancer. ADC exhibited the highest mutational diversity, particularly in RTK/MAPK pathway genes (EGFR, KRAS, BRAF, ERBB2, PIK3CG). Notably, EGFR mutations were identified in 26.7% of ADC cases, including exon 19 deletions (5 cases), exon 21 missense mutations (2 cases), and exon 20 insertions (3 cases) and a novel EGFR exon 20 duplication (p.Ser768_Asp770dup). SqCC showed frequent mutations in KMT2D, ARID2, and FBXW7, suggesting a role for epigenetic dysregulation. One SqCC case harbored a rare EGFR p.Glu866Gly mutation. SCLC was enriched for TP53 (43%) and RB1 (14%) mutations, along with alterations in FAT4 and LRP1B. Importantly, therapeutically actionable mutations were identified in 91.5% patients, including those with NCCN-recommended (25.5%) and FDA-approved off-label drug targets (68.1%). These findings underscore the value of WES in uncovering clinically relevant mutations and support the integration of genomic profiling into precision oncology strategies for Indian lung cancer patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13193-025-02359-9.