[Effect of SMARCA4 mutations on the outcomes of patients with advanced EGFR mutant lung adenocarcinoma].

Objective: To investigate the impact of SMARCA4 mutations on the outcomes of patients with advanced lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutations. Methods: In the Memorial Sloan Kettering Cancer Center (MSK) MetTropism study, 960 patients with advanced EGFR-mutated lung adenocarcinoma were screened and included in the MSK cohort, composing of 313 males and 647 females, with a median [M(Q₁, Q₃)] age of 64 (56, 72) years. A retrospective analysis was conducted on the data of 178 patients with advanced EGFR-mutated lung adenocarcinoma who received EGFR tyrosine kinase inhibitors (TKIs) treatment in the Department of Oncology, the First Affiliated Hospital of Nanjing Medical University, from January 2018 to December 2022. Among these patients, 69 were males and 109 were females, with a median age of 63 (54, 69) years. The follow-up of patients from the First Affiliated Hospital of Nanjing Medical University was conducted up to December 31, 2023, with a median follow-up time of 26.6 (95%CI: 24.6-28.6) months for the entire cohort, and 29 patients were lost to follow-up. Survival curves were plotted using the Kaplan-Meier method, and the log-rank test was used to compare the relationship between SMARCA4 gene alternations and prognosis. Results: In the 960 patients of the MSK cohort with advanced EGFR-mutated lung adenocarcinoma, the SMARCA4 gene alternations rate was 4.2% (40/960). The median overall survival (OS) for patients without SMARCA4 gene alternations was 41.5 (95%CI: 35.6-47.3) months, which was superior to that of patients with SMARCA4 gene alternations [15.6 (95%CI: 7.9-23.4) months, P<0.001]. Patients with SMARCA4 gene alternations had a higher risk of mortality, with an HR (95%CI) of 1.97 (1.35 to 2.88). Among the 178 patients with advanced EGFR-mutated lung adenocarcinoma from the First Affiliated Hospital of Nanjing Medical University, the SMARCA4 gene alternations rate was 4.5% (8/178). The median progression-free survival (PFS) for patients without SMARCA4 gene alternations was 16.1 (95%CI: 12.2-20.0) months, which was superior to the median PFS of patients with SMARCA4 gene alternations [6.0 (95%CI: 1.3-10.7) months, P<0.001]. The median OS for patients without SMARCA4 gene alternations was 50.1 (95%CI: 28.1-72.1) months, which was also superior to the median OS of patients with SMARCA4 gene alternations [17.6 (95%CI: 15.4-19.8) months, P=0.001]. Conclusion: SMARCA4 alternation is an important factor associated with poor prognosis in patients with advanced EGFR-mutant lung adenocarcinoma.