An advanced non-small cell lung cancer patient with EGFR and KRAS mutations, and PD-L1 positive, benefited from immunotherapy: a case report

Background: Patients with epidermal growth factor receptor (EGFR )-sensitive mutations have great opportunity to benefit from EGFR-tyrosine kinase inhibitors (TKI) in non-small cell lung cancer (NSCLC). Although the presence of KRAS mutations is predictive of lack of benefit from EGF-TKI therapy for NSCLC, patients with KRAS mutations could be more sensitive to PD-1/PD-L1 inhibitors. However, the application of immunotherapy in EGFR mutated NSCLC patients is still controversial. Case Description: In this study, we reported the case of a 56-year-old NSCLC patient who harbored the mutations of EGFR L858R and KRAS G12D, with a high tumor mutational burden value and positive programmed death-ligand 1 (PD-L1) expression. Considering the EGFR sensitive mutation, gefitinib combined pemetrexed was administered; however, the disease progressed soon after. The patient then underwent combined treatment of bevacizumab (400 mg), camrelizumab (200 mg), and pemetrexed (0.8 mg), and partial response was observed after 4 months. When chemotherapy was removed from the combined treatment, liver metastasis was detected. Interestingly, the disease was well controlled when the combined treatment of bevacizumab, camrelizumab, and pemetrexed was resumed. Overall, the patient benefits lasted more than 17 months. Conclusions: Our results indicated that immunotherapy may be a potential choice in NSCLC with EGFR and Kirsten rat sarcoma virus (KRAS) mutations, and combined chemotherapy may effectively increase therapeutic efficiency during combined immunotherapy.