Thoracic malignant solitary fibrous tumors: A population-based study of survival

This study characterizes the overall survival (OS) and cause specific survival (CSS) of patients with thoracic malignant solitary fibrous tumors.

Eighty-two patients with malignant solitary fibrous tumors of the lung, pleura or mediastinum, diagnosed from 2001-2007, were retrospectively analyzed using the population-based Surveillance, Epidemiology, and End Results database.

Among 77 patients with available staging information, 42% (n=32) had localized disease, 31% (n=24) had regional disease extension (without nodal involvement) and 27% had regional-nodal (n=2) or distant (n=19) metastases. Cancer-directed surgery was performed in 85%; radiation was performed in 16%. The 1-year, 5-year and median OS were 87%, 49% and 4.6 years respectively. The 1-year, 5-year and median CSS were 89%, 61% and 5.7 years respectively. Less advanced stage and undergoing cancer-directed surgery were favorable prognostic factors. For localized, regional and distant stage the median OS was: not reached at 6.3 years, 4.4 years and 2.0 years respectively (P=0.021); the median CSS was not reached at 6.3 years, 5.0 years and 2.4 years (P=0.068). For patients undergoing versus not undergoing surgery, the median OS was 4.9 vs 0.9 years (P=0.053) and median CSS was 5.7 vs 0.9 years (P=0.011). Tumor size was not significant.

From a population-based analysis of patients with thoracic malignant solitary fibrous tumors, stage and cancer-directed surgery had the greatest impact on OS and CSS. While being amenable to surgery likely reflects more indolent disease and/or better performance status and cardiopulmonary function, the significantly favorable impact of surgery also likely reflects a therapeutic benefit.