EGFR Mutation Prevalence in Non-Small Cell Lung Cancer in West-European Patient Population

The prevalence of EGFR mutations in West-European patients with non-small cell lung cancer (NSCLC) was found to be statistically substantial, especially when considering the benefit of adjuvant osimertinib for this patient population.

Liesbeth M. Hondelink, MD, Leiden University Medical Center, the Netherlands, and colleagues noted the ADAURA study associated improved disease-free survival (DFS) with treatment with adjuvant osimertinib among patients with resected EGFR-mutated lung adenocarcinoma. They explained, however, “data on prevalence rates and stage distribution of EGFR mutations in non-small cell lung cancer in Western populations are limited since upfront EGFR testing in early-stage lung adenocarcinoma is not common practice.”

In this unique, real-world, unselected cohort study, routine unbiased testing with targeted next-generation sequencing was performed on 486 West-European patients with lung adenocarcinoma regardless of TNM stage between January 1, 2014 and February 1, 2020. From this testing, clinical and pathological data, including co-mutations and morphology, were collected. Cases demonstrating EGFR mutations were compared to cases demonstrating KRAS mutations to identify characteristics unique to EGFR.

The study found EGFR mutations in 53 of 486 lung adenocarcinomas (11%). The prevalence was higher in stages 0 to 3A (13%) compared with stages 3B to 4 (9%). There were 9 out of 130 (7%) patients with stage 1Bto 3A disease (7%) that fit the ADAURA criteria. Compared to late-stage cases with EGFR mutations, early-stage cases exhibited more L858R mutations (P = .02), fewer exon 20 insertions (P = .048), fewer TP53 co-mutations (P = .007), and were more frequently never-smokers (P = .04). KRAS-mutated cases demonstrated a more even distribution across TNM stages vs EGFR-mutated cases as well.

“Our data add to a growing body of evidence that suggests that EGFR-mutated lung cancer, although seemingly one homogeneous group, actually consists of several genomic and clinical subgroups,” wrote Dr Hondelink, et al, concluding, “it would be of interest to investigate potential differences in outcomes between patients with low- and high-risk phenotypes receiving adjuvant TKIs such as osimertinib, in order to guide future therapy decisions.”

Source:

Hondelink LM, Ernst SM, Atmodimedjo P, et al. Prevalence, clinical and molecular characteristics of early stage EGFR-mutated lung cancer in a real-life West-European cohort: Implications for adjuvant therapy. Eur J Cancer. 2023;181:53-61. doi:10.1016/j.ejca.2022.12.010