Clinicopathological Characteristics and Prognostic Factors of Pulmonary Sarcomatoid Carcinoma: a Large Population Analysis

Background: This study was conducted to identify the clinicopathological characteristics and survival outcomes of pulmonary sarcomatoid carcinoma (PSC), and to compare prognostic factors between elderly (>= 65 years) and non-elderly (<65 years) patients. Methods: The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients diagnosed with PSC between 2004 and 2016. The Kaplan-Meier method was used for overall survival (OS) and cancer-specific survival (CSS) analysis. The Cox proportional hazards model was used to detect independent prognostic factors. A propensity score matched (PSM) analysis was conducted to compare OS and CSS in elderly versus non-elderly PSC patients. Results: A total of 1,039 eligible cases were identified, with a median follow-up of 6 months. The 5-year OS and CSS rates were 12.3% and 18.7%, respectively, and the median survival was 6 months. Multivariate analysis revealed that female (HR =0.750, P<0.004), surgery (HR =0.484, P<0.001), chemotherapy (HR =0.504, P<0.001), and radiation (HR =0.801, P=0.041) were independent favorable prognostic factors. There was a significant difference in the OS and CSS rates between elderly and non-elderly patients after PSM (P=0.007 and P=0.017, respectively). In multivariate analysis, the predictors for OS in the elderly patients were gender, tumor stage, and chemotherapy, whereas in the non-elderly patients, the predictors were tumor stage, chemotherapy, and surgery. Conclusions: The PSC patients in our study had poor survival outcomes. Comprehensive treatment, including surgery, chemotherapy, and radiotherapy, could improve patient prognosis. Elderly patients had different clinicopathological characteristics, compared to non-elderly patients.