Landscape of lung cancer molecular biology in a NON-selected population.

Abstract

e20648 Background: The molecular study of non-small cell lung cancer (NSCLC) allows for targeted treatment. EGFR and ALK alterations have been observed in 14% and 5% of Caucasian patients (p) respectively. These alterations are mainly detected in women with adenocarcinoma (ADC) and non-smokers. In a non-selected (all comers) NSCLC population from Ávila (Spain) we found a different profile. Methods: We collected data from 185 consecutive p the Pathology Department database of Hospital Nuestra Señora de Sonsoles from 2012 to 2017. All p were tested for EGFR and ALK. Analyses were done with Cobas or Therascreen tests. Results: EGFR mutations were found in 11 p out of 185 (6.7%). Histology was ADC in 8 p (72.7%) and squamous cell carcinoma (SC) in 3 p (27.3%). Male (m) & smokers: 4/11 (36,4%). The type of mutation was: Exon 20: 3 p (27.3%). 2 m and 1 female (f). 2 smokers and 1 former smoker. 2 ADC and 1 SC; Del 19: 4 p (36.4%). 1 m and 3 f. 1 non-smoker, 2 former smokers and 1 smoker. 3 ADC and 1 SC; Exon 21: 4 p (36,4%). 2 m and 2 f. 3 non-smokers and 1 smoker. 3 ADC and 1 SC. All p. received treatment with 1st generation anti-EGFR drugs for a median 6.4 months (m). Progression Free Survival was 6.39 m (exon 20: 5.1 m; Del 19: 6.5 m; exon 21: 7.2 m). Overall survival was 18.0 m (exon 20: 26.1 m; Del 19: 18.2 m; exon 21: 11.8 m). ALK translocation was found in 5 p out of 158 (3.2%). Histology was ADC in 3 p (60%) (all f, 2 non-smokers and 1 former smoker) and SC in 2 p (40%) (2 smoker m.) Conclusions: Although the small sample size prevents definitive conclusions, EGFR mutations in exon 20 are more frequent in smokers and mutations in exon 21 in non-smoking patients with ADC. ALK translocation was observed independent of sex, tobacco or histologic type. For EGFR and ALK alterations, screening based on sex or pathology would have missed findings with therapeutic implications. We conclude it is important to extend the analysis of molecular alterations to all patients with NSCLC since more of them could benefit from targeted drugs.[Table: see text]