Advanced non-small cell lung cancer with SMARCA4 deficiency: a case report.

SMARCA4-deficient non-small cell lung cancer (SMARCA4-dNSCLC) is an uncommon malignant epithelial neoplasm originating in the lung, characterized by poorly differentiated and highly invasive pathological features, and associated with a poor prognosis. Currently, there is no standardized treatment protocol for SMARCA4-dNSCLC, as it generally exhibits a poor response to conventional chemotherapy regimens. Furthermore, the absence of typical driver gene mutations in lung cancer renders it insensitive to targeted therapies. We report the case of a 49-year-old Asian male patient with stage IV non-small cell lung cancer exhibiting SMARCA4 deficiency, who demonstrated a rapid response following treatment with a combination of nab-Paclitaxel, cisplatin, and bevacizumab. However, the patient ultimately experienced treatment failure due to disease progression from brain metastases, resulting in an overall survival (OS) of approximately 12 months. This case demonstrates the complicated clinical features of SMARCA4-deficient lung cancer, enriches the limited relevant clinical literature, and provides supplementary clinical data for this rare tumor subtype. While patients with SMARCA4-deficient lung cancer may benefit from chemotherapy combined with anti-angiogenic targeted therapy, the overall prognosis remains poor.