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.