To explore SMARCA4-deficient non-small cell lung cancer in the chest Clinical characteristics, imaging manifestations, histopathological features and treatment prognosis of patients with SMARCA4-dNSCLC and SMARCA4-deficient undifferentiated tumors (SMARCA4-UT) To enhance the understanding of the disease.

A retrospective analysis was conducted on 37 patients with SMARCA4-deficient tumors (SMARCA4-DT) in the chest admitted to the Second Affiliated Hospital of Army Medical University from November 2022 to April 2025. They were divided into 10 cases of SmarCA4-deletion non-small cell lung cancer (SMARCA4-dNSCLC) and 27 cases of SmarCA4-deletion undifferentiated tumor (SMARCA4-UT). The gender, age, smoking history, clinical symptoms, Eastern Cooperative Oncology Group (ECOG) performance status score, tumor CT location, tumor size, tumor density, uniformity of tumor enhancement, metastasis site, stage, histopathological characteristics and prognosis of the patients were compared.

Compared with SMARCA4-dNSCLC, SMARCA4-UT has a larger tumor diameter, extremely irregular tumor density and enhancement uniformity, a later clinical stage, more common mediastinal lymph node metastasis, and a higher Ki-67 index. The Overall Survival (OS) is short. The difference was statistically significant (P<0.05); There was no statistically significant difference in clinical manifestations, ECOG performance status score, and distant metastasis sites (P>0.05). The histological morphology of SMARCA4-dNSCLC presents various poorly differentiated NSCLC morphologies. The histological morphology of SMARCA4-UT is poorly differentiated and has lost the morphological characteristics of epithelial carcinoma, presenting as rhabdoid morphology. Surgery is the main treatment for early-stage tumors, while chemotherapy combined with immunotherapy is the core regimen for advanced-stage tumors. However, the Overall prognosis of both types of tumors is extremely poor, and the Median Overall Survival (mOS) is relatively short. The median survival period of SMARCA4-dNSCLC patients in this article was 14 months, while that of SMARCA4-UT was 5 months, and the difference was statistically significant (P<0.05).

Both SMARCA4-dNSCLC and SMARCA4-UT have the characteristics of high invasiveness, rapid disease progression and poor prognosis. However, SMARCA4-UT has a higher degree of malignancy, faster progression and worse prognosis. There are differences between the two in terms of imaging manifestations, histopathological features and prognosis. SMARCA4 can be routinely incorporated into the immunohistochemical detection of poorly differentiated and undifferentiated thoracic tumors in clinical practice. Early identification and accurate classification are of great clinical significance for evaluating the condition and guiding treatment.