Evaluation on the Distribution of EGFR, KRAS and BRAF Genes and the Expression of PD-L1 in Different Types of Lung Cancer

OBJECTIVE: To evaluate the distribution of high frequency mutant genes and the expression of PDL1 in different types of lung cancer. METHODS: This retrospective analysis was conducted on 330 patients who were diagnosed with primary lung cancer and treated in our hospital from October 2018 to October 2020. The patients were listed into non-small cell carcinoma group (101 cases), squamous carcinoma group (28 cases) and adenocarcinoma group (201 cases) according to their pathological results. The gene mutations were detected using EGFR, KRAS, and BRAF gene mutation detection kits, and the expression of PDL1 was detected by immunostaining. The mutation of EGFR, KRAS and BRAF genes and PDL1 expression in patients with different types of lung cancer were compared. RESULTS: The patients in the adenocarcinoma group had the highest incidence of EGFR gene mutation, the mutation rate of the gene whose mutation location was exon 18 was significantly higher, and the difference between each group was statistically significant (P < 0.05). The patients in the adenocarcinoma group had the highest incidence of KRAS gene mutation, the mutation rate of the gene whose mutation location was exon 2 was obviously the highest, exon 15 was the lowest, and the difference between each group was statistically significant (P < 0.05). There was no significant difference in the distribution of BRAF gene mutations among groups, and all mutations occurred on exon 15, with no statistically significant difference between each group (P > 0.05). PD-L1 expression in NSCLC patients was significantly higher than that in other lung cancer patients (P < 0.05). CONCLUSION: EGFR and KRAS genes showed obvious specific expressions in patients with different types of lung cancer and they were more common in patients with lung adenocarcinoma. Gene mutation and PDL1 expression are high in patients with lung adenocarcinoma.