Epidemiological features and survival outcomes in patients with malignant pulmonary blastoma: A US population-based analysis

Background: Pulmonary blastoma (PB) is a rare lung primary malignancy with poorly understood risk factors and prognosis. We sought to investigate the epidemiologic features and long-term outcomes of PB. Methods: A population-based cohort study was conducted to quantify the death risk of PB patients. All subjects diagnosed with malignant PB from 1988 to 2016 were screened from the Surveillance, Epidemiology and End Results database. Cox regression model of all-cause death and competing risk analysis of cause-specific death were performed. Results: We identified 177 PB patients with a median survival of 108 months. The 5 and 10-year survival rate in all PB patients were 58.2 and 48.5%, as well as the 5 and 10-year disease-specific mortality were 33.5 and 38.6%. No sex or race disparities in incidence and prognosis was observed. The death risk of PB was significantly associated with age at diagnosis, clinical stage, histologic subtype and surgery treatment (p<0.01). On multivariable regression analyses, older age, regional stage and no surgery predicted higher risk of both all-cause and disease-specific death in PB patients. Conclusion: We described the epidemiological characteristics of PB and identified its prognostic factors that were independently associated with worse clinical outcome.