Abstract 142P
Background
lung cancer is considered as the most common cause of cancer death in world. Adenocarcinoma (ADK) is currently the most common histological subtype of this disease, accounting for 85% of all lung cancer cases. The majorities of patients with lung adenocarcinoma have advanced disease and are not candidates for local therapy. The epidermal growth factor receptor (EGFR) represents a potential molecular target for personalized therapy with (ITKs) in Lung ADC. The aim of this study is to define the association of EGFR mutations with predominant histological pattern lung adenocarcinoma in Moroccan population.
Methods
135 FFPE tumours diagnosed with lung adenocarcinoma were included between November 2017 and May 2020. Histological subclassification was registered by a pathologist. Automatic direct sequencing was performed for samples with Tumor cells >30% ; The therascreen EGFR RGQ Kit was used for specimen with tumor cells <30%.
Results
27 lung adenocarcinoma were EGFR mutated, more frequently found among women (30%) than in men (15,7%) and non-smokers (non-smokers vs active smokers, 35.7% against 8%). Regarding histological subtypes, the most frequent one was acinar (40%), followed by solid (35,25%), papillary (14.28%) and lepidic (5,71%). EGFR mutation tend to be common in papillary predominant (40%), followed by acinar predominant (33,33%), lepidic predominant (16,6%) and solid predominant (8,1%). EGFR exon mutation distribution was similar to that generally reported in the literature. The main types were in-frame deletions in exon 19 (55,55%), followed by the missenses substitutions in exon 21 (37,03%), exon 20 mutations (11,11%) and exon 18 (3,7%). Exon 19 were significantly more frequent in tumors with papillary pattern (p=0,048), while exon 21 substitutions tend to be associated with acinar predominant pattern (p=0,017). Thyroid transcription factor-1 expression wasn’t seen in two EGFR-mutant-positive tumors. A significant association was revealed between EGFR mutations and female gender (p < 0,05), non-smokers (p <0.001), acinary predominant pattern. (p = 0.03).
Conclusions
In our population, the female gender, non smoking status and acinar predominant pattern may predict the presence of EGFR mutation in lung adenocarcinoma.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Hinde El Fatemi.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.