[Clinicopathological Characteristics and Prognosis Analysis of 
39 Patients with Pulmonary Sarcomatoid Carcinoma].

ABSTRACT

BACKGROUND: Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of non-small cell lung cancer (NSCLC), which is featured by low incidence, high malignancy rate, robust aggressive behavior and inferior prognosis. To date, there is no standardized treatment. The aim of this study is to better understand and accumulate more clinical experience of the disease by summarizing the clinicopathological features, diagnosis methods, therapeutic regimen and prognostic factors of PSC. METHODS: A total of 39 patients with PSC who diagnosed and received treatment in Beijing Chest Hospital from December 2013 to December 2023 were retrospectively recruited, and information including demographic characteristics, clinicopathological features, tumor-node-metastasis (TNM) stage, diagnosis method and therapeutic regimen were carefully collected. Meanwhile, follow-up was conducted. Kaplan-Meier method was used to analyze the prognostic factors of the disease. RESULTS: The PSC patients in this study ranged in age from 45 to 76 years old, including 35 males and 4 females. There were no specific clinical manifestations of PSC at initial diagnosis. Among the 39 patients, 20 underwent surgical resection and 19 received palliative chemoradiation or symptomatic supportive treatment. The 1-year and 5-year survival rates were 61.90% and 35.20% respectively. Univariate analysis indicated that family history of carcinoma, primary tumor site, TNM stage, lymph node metastasis, distant metastasis, whether or not received surgical resection, surgical method, treatment regimens, tumor tissue programmed cell death ligand 1 (PD-L1) expression ≥1% and mesenchymal-epithelial transition factor (MET) pathway abnormalities were correlated with the overall survival (OS) of patients (P<0.05). In the subsequent multivariate analysis, lymph node metastasis emerged as the only independent prognosticator in predicting inferior OS (P=0.037). CONCLUSIONS: PSC is rarely seen in clinical practice and commonly occurs in elder men with smoking history. Tumor tissue PD-L1 expression ≥1% and MET abnormalities may predict inferior prognosis of PSC and lymph node metastasis was determined as the independent prognosticator of PSC. Surgical resection along with adjuvant medical treatment is the cornerstone for early and locally advanced patients, and the clinical utility of molecular targeting therapy and immunotherapy in PSC needs to be further investigated.