Primary pulmonary leiomyosarcoma: A population-based study.

OBJECTIVES: Primary pulmonary leiomyosarcoma (PPL) is a rare diagnosis with poorly understood clinicopathological characteristics and disease progression. What we know is derived from limited case reports, so identification of features associated with patient survival is warranted.

MATERIALS AND METHODS: A population cohort study was conducted using prospectively extracted data from the Surveillance, Epidemiology and End Results (SEER) database for patients with histological diagnoses of PPL from 1973 to 2013 including demographic, treatment and outcome data.

RESULTS: A total of 231 patients with PPL were included (mean 65.8 ± 14.9 years-of-age). 43 were categorized with a regional stage, and 60 had localized stage, whereas 70 had distant stage. Most (60.4%) patients received cancer-directed surgery, and radiotherapy was performed for 14.1% of patients. Median overall survival (OS) was 14.0 months, and 1-, 3- and 5-year OS for PPL patients was 52.7%, 29.0% and 22.2%, respectively. Cancer-directed surgery significantly improved median OS for patients with PPL by almost 29.0 months (33.0 vs 4.0 months; p < .01). Multivariate Cox analysis showed that distant stage was independent prognostic factors for PPL (HR = 2.22, 95% CI 1.30-3.79). Conversely, cancer-directed surgery was an independent protective factor and this decreased risk of death by 57% (HR = 0.43, 95% CI 0.27-0.67) for patients with PPL.

CONCLUSION: PPL is a rare pathological lung cancer, surgical resection and distant stage were associated with prognosis. In order to understand PPL more thoroughly, more cases with adequate information are required.