Abstract 185P
Background
Despite many advances in molecular pathological procedures and improved clinical outcomes, in advanced disease but also as adjuvant therapies, many NSCLC patients do not receive full panel testing.
Methods
In this retrospective analysis, we used results from NGS testing of 154 patients with adenocarcinoma (AC) or squamous-cell carcinoma (SCC) treated at LMU university hospital Munich between 2018 and 2021. We compared different clinicopathological features and patients’ baseline characteristics with results of NGS testing. We used t-test and ANOVA to compare metric variables and Chi2-test and Fisher’s Exact test to compare categorical variables.
Results
NGS testing found mutations in 107 (69.5%) patients, 16.9% (n = 26) of whom had more than one of the five most common mutations. Mean age was 62.6 years (SD = 12.6) and 55.8% of patients were male. The majority of patients had AC (78.6%), and were metastasized (64.9%). Patients with mutations had significantly higher PD-L1 expression than those without mutations (36.8 vs. 18.8%, p-value = 0.003). Mean PD-L1 expression was 49.0% in patients with more than one mutation; 44.5% in MET, 34.2% in PIK3CA, 28.9% in TP53, 28.8% in KRAS, and 21.9% in EGFR. EGFR mutations were more common in patients with metastases vs. those without (17.0 vs. 9.3%), whereas TP53, PIK3CA and BRAF were less common in patients with metastases (TP53: 24.0 vs. 27.8%, PIK3CA: 5.0% vs 9.3%, BRAF 3.0% vs. 7.4%). AC patients had 26 different mutations. The five most common were TP53 in 24.0%, KRAS in 19.0%, EGFR in 14.9%, MET in 11.6%, and PIK3CA in 2.5%. In SCC, we found 13 different mutations, with the most common ones being TP53 in 30.3%, PIK3CA in 21.2%, KRAS in 12.1%, EGFR in 12.1%, and MET in 3.0%. Distribution of the five most common mutations was significantly different between AC and SCC (p-value = 0.04).
Conclusions
Mutation profiles differed by histological type and metastases status, and were significantly associated with PD-L1 expression. KRAS and EGFR mutations in SCC were more common than previously reported. These results might help identify patients who are more likely to harbor a treatable mutation and can help physicians plan diagnostics especially when tissue material is limited.
Legal entity responsible for the study
Department of Medicine V, University Hospital, LMU Munich.
Funding
Has not received any funding.
Disclosure
The author has declared no conflicts of interest.