Study Assesses Associations Between EGFR Mutation Subtypes, Patient Characteristics

Different epidermal growth factor receptor (EGFR) mutation subtypes are associated with different clinical and demographic characteristics among patients with advanced non-small cell lung cancer (NSCLC) according to research presented at the European Lung Cancer Conference (ELCC) 2016.¹

Previous studies have demonstrated that EGFR mutations are more common in advanced NSCLC and are more likely to be present in patients of Asian ethnicity, female patients, never-smokers, and those with adenocarcinoma histology; however, it is unclear how mutation subtypes are distributed across clinical and demographic groups.

Researchers analyzed data from the IGNITE and ASSESS trials, which included a total of 4399 patients with advanced NSCLC who were successfully tested for EGFR mutations. Of those, 1242 had an EGFR mutation.

Results showed that stage 4 disease was associated with the presence of an EGFR mutation as compared with stage IIIa cancer (odds ratio [OR], 0.56; 95% CI, 0.40-0.81) and stage IIIb disease (OR, 0.62; 95% CI, 0.47-0.81).

Researchers found that rare mutation subtypes were relatively more frequent in smokers than never- smokers as compared with more common mutations like L858R/exon 19 deletions (OR, 2.6; 95% CI, 1.5-4.5; P = .0005).

Further, researchers observed EGFR mutation subtype heterogeneity for smoking status, age, ethnicity, and histology (P < .05). The study revealed that Caucasian patients, those younger than age 65, and those with adenocarcinoma were more likely to have exon 19 deletions than other mutation subtypes. Exon 20 insertions were only present in patients with adenocarcinoma histology.

Reference

1. Han B, Ratcliffe M, Haddad V, et al. Association of EGFR mutation subtypes with clinical and demographic characteristics of patients (pts) with aNSCLC: IGNITE and ASSESS pooled analysis. Poster presentation at: European Lung Cancer Conference 2016; April 13-16, 2016; Geneva, Switzerland.