AbstractOBJECTIVESPulmonary carcinosarcoma (PCS) is a rare neoplasm. This study explored the clinicopathological characteristics and survival outcomes of PCS.METHODSThe Surveillance, Epidemiology and End Results (SEER) database (1988–2014) was queried for PCS. Overall survival (OS) was evaluated by multivariable Cox regression and nomograms were constructed to predict 3-year OS for PCS. Prognostic performance was evaluated using concordance index and area under the curve analysis. In M0 surgically treated patients, interaction assessments were performed using likelihood ratio tests. Subgroup analysis was performed according to patient age. The clinical features of PCSs were further compared to other non-small-cell lung cancers (NSCLCs).RESULTSMultivariable analysis identified age [hazard ratio (HR) 1.03, 95% confidence interval (CI) 1.01–1.04], surgery (HR 0.53, 95% CI 0.36–0.77) and chemotherapy (HR 0.51, 95% CI 0.36–0.73) as significantly associated with OS. The nomogram had a concordance index of 0.747 and an area under the curve of 0.803. The association between age and OS was stronger in those receiving pneumonectomy (P = 0.04 for interactions) compared to those that did not (HR 5.14, 95% CI 1.64–16.07), and was associated with a poorer outcome compared to lobectomy amongst the elderly (age ≥ 70 years). Patients with PCS were more likely to receive surgical treatment and had lower lymphatic metastasis compared to adenocarcinoma, squamous cell carcinoma and large cell carcinoma (all P < 0.05).CONCLUSIONSPCS had unique clinical features compared to common types of NSCLCs in terms of lymphatic invasion and surgical treatment. Pneumonectomy was associated with poorer survival in elderly patients.