396P - Mutational profiling by next generation sequencing in patients with metastatic non-small cell lung carcinoma

Background

According to GLOBOCAN 2020 lung cancer is the 2^nd most common cancer worldwide (11.4%) accounting for highest cancer related mortality (18%). NSCLC is divided into molecular subtypes based on oncogenic drivers. NCCN strongly recommends performing broad panel-based testing like NGS in mNSCLC patients.

Methods

A hospital based prospective observational study on 88 patients during a period of 1 year. All patients aged 18 years or above, diagnosed as metastatic non small cell lung carcinoma and evaluated for oncogenic driver mutation by NGS method were included in the study. NGS was performed in fresh frozen paraffin embedded (FFPE) tissue block. We had included 5 diver mutations e.g. EGFR, EMLA- ALK, BRAF, MET, ROS1 which are under current recommendations from NCCN guidelines and have specific targeted therapy recommended against them.

Results

Majority of mNSCLC cases were in the age group of 41-50 years (n=30, 34.1%) with average age at presentation being 53.74 years. Male: female ratio was 1.14:1 and most patients were non smokers (n=47, 53.4%). Adenocarcinoma (n=75, 85.2%) was the most common histological subtype followed by squamous cell carcinoma (n=10, 11.4%). mNSCLC cases with adenocarcinoma histology had highest mutational burden (n=55, 62.5%). EGFR (n=32, 56.14%) was the most common mutation detected followed by EMLA-ALK4 (n=19, 33.33%). ROS1 mutation was detected in 4 patients while MET and BRAF V600E mutations were detected in 1 each. Most common variant in EGFR mutation was Exon 19 (n=17, 53.12%) followed by Exon 20 (n=8, 25%) and Exon 21 (n=6, 18.75%). EGFR mutation in Exon 18 was the rarest mutation (n=1, 3.13%). 2 patients with EGFR Exon 20 had upfront T790M mutation. p.Glu746_Ala750 was the most common variant in EGFR Exon 19 mutation while L858R was the commonest variant in EGFR Exon 21 mutation. Skeleton was the most common metastatic site across all subtypes of driver mutations while brain was the most common site in the EMLA-ALK4 mutated patients.

Conclusions

Geographical and demographic differences of the North-Eastern part of India may have impact on the high mutational burden among lung cancer patients. 64.77% of our mNSCLC patients had driver mutation of which 56.14% had EGFR and 33.33% had EMLA-ALK mutation.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Novartis Healthcare had provided coupons for NGS panel study.

Funding

Has not received any funding.

Disclosure

The author has declared no conflicts of interest.