Molecular Dx Significance 7/10

Large UK Cohort Maps KRAS Mutation Landscape in Non-Small Cell Lung Cancer

Analysis of 3,283 NSCLC samples from 38 UK centres using amplicon-based NGS identified KRAS variants in 34% of cases, with G12C, G12V, and G12D as the most prevalent mutations. Co-mutations in PIK3CA and BRAF were frequent, while PD-L1 expression did not differ between KRAS wild-type and mutant tumors. These data provide a UK-specific reference for G12C-targeted therapy eligibility and companion diagnostic strategies.

The original study

Prevalence and breakdown of

Authors
Niesner ICC, Balbi KJ, Poskitt B, Gemma C, Linares J, Allen D, et al.
Journal
Journal of clinical pathology
Type
Journal Article, Multicenter Study
PMID
39890446
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Original abstract

Kirsten rat sarcoma viral oncogene (KRAS) is a frequently mutated oncogene in lung cancer, now amenable to targeted therapy with allele-specific G12C inhibitors. Non-small cell lung cancer (NSCLC) driver mutations show geographical variability and therefore the KRAS mutation breakdown, co-occurring oncogenic mutation rate and associated PD-L1 expression were studied in a large UK cohort. We interrogated archival clinical next-generation sequencing (NGS) data over 5 years. 3283 NSCLC samples were included, referred from 38 centres over 4 years. Somatic mutation hotspots in cancer-associated genes were analysed using ampliseq/ion-torrent based NGS assays. In a subset of the cohort, PD-L1 scores were also collated. 1118 KRAS variants were detected. Class I mutations occurred most frequently (86.94%), with KRAS G12C, G12V and G12D being most prevalent. Class II (7.96%), III (4.65%) and IV (0.45%) mutations were also detected and mutations in PIK3CA and BRAF were the most frequently observed co-mutations. No significant difference in PD-L1 expression was found between KRAS wild-type and mutant tumours.