Abstract
BACKGROUND: Patients with non-small cell lung cancer (NSCLC) carrying SMARCA4 mutations (SMARCA4-Mut) tend to have more advanced disease and a poor prognosis. However, due to the rarity of this mutation and the lack of related studies, the characteristics of SMARCA4-Mut NSCLC patients remains poorly determined. To clarify the clinical characteristics and prognostic factors of SMARCA4-Mut NSCLC, we initiated the present study to provide a clinical reference. METHODS: We used data from two cohorts of NSCLC-SMARCA4-mutated samples: The Cancer Genome Atlas (TCGA) database and our center's clinical data. The TCGA database was used to obtain 481 NSCLC-SMARCA4-Mut samples for clinical characterization. The center collected data on 224 consecutive NSCLC patients treated between December 2020 to July 2022. Among them, 26 harbored SMARCA4 mutations, and 20 were eligible for inclusion in the study. Clinical, pathological, and molecular features, as well as prognostic role of SMARCA4 mutations were analyzed. Additionally, we analyzed the prognostic impact of Napsin A expression in SMARCA4-Mut patients. RESULTS: The TCGA database included 480 patients with SMARCA4-Mut NSCLC, 311 males (64.8%) and 169 females (35.2%), with a median age of 67 years. Among the 20 SMARCA4-Mut patients in our center series, 12 (60%) were males and 8 (40%) females, with a median age of 63. The intergroup prognostic correlation analysis showed that SMARCA4-Mut patients had significantly worse prognosis than those the wild-type SMARCA4 (SMARCA4-WT) (P=0.04). Within the SMARCA4-Mut group, patients with Napsin A expression had longer overall survival (OS) (P=0.03) than those without expression. Median survival in the Napsin A-positive and negative groups was 32 and 15 months, respectively. According to time-dependent receiver operating curve analysis, patients with Napsin A expression had significantly longer first-line treatment progression-free survival (PFS1) [area under the curve (AUC) =0.748] and OS (AUC =0.586). No prognostic value of Napsin A was found in patients SMARCA4-WT patients. CONCLUSIONS: SMARCA4-Mut is an adverse prognostic feature in NSCLC patients. Napsin A expression in SMARCA4-Mut patients is associated with prolonged OS.