Malignant Solitary Fibrous Tumors of the Pleura: Retrospective Review of a Multicenter Series

Abstract: Introduction: Available data on the malignant solitary fibrous tumor of the pleura (mSFTP), a very rare neoplasm with unpredictable prognosis, are scarce. The aim of this study is to collectively analyze the aggregated data from the largest series in the English literature to date, a multicenter, 10-year study of 50-cases. Methods: We retrospectively reviewed the clinical records of patients who underwent surgical resection for mSFTP in the period between January 2000 to July 2010. Long-term survival (LTS) and 5-year disease-free survival were analyzed in detail. Results: There were 24 men and 26 women (median age, 66 years; age range, 44-83 years). Thirty-two patients (64%) were symptomatic. A malignant pleural effusion was diagnosed in 12 cases. Surgical resection included isolated mass excision in 13 patients and extended resection in 35. In the remaining two cases only biopsies were undertaken. The resection was complete in 46 cases (92%). Adjuvant treatment was administered to 15 patients. Median follow-up was 116 months (range, 18-311 months). Overall LTS and disease-free survival were 81.1% and 72.1%, respectively. Fifteen patients (30%) experienced a relapse of the disease. Complete resection yielded much better LTS than partial resection (87.1% versus 0%; p < 0.001). At the Cox regression analysis, incomplete resection (hazards ratio [HR]: 39.02; 95% confidence interval [CI]: 4.04380.36; p = 0.002) and malignant pleural effusion (HR: 3.44; 95%CI: 0.98-12.05; p = 0.053) were demonstrated to be risk factors for earlier death. At multivariate analysis, chest-wall invasion and malignant pleural effusion increased the risk of recurrence (HR: 4.34; 95%CI: 1.5%-12.6%; p = 0.007 and HR: 3.48; 95%CI: 1.1%-11.0%; p = 0.038, respectively). Conclusions: Surgical resection remains the treatment of choice for mSFTP. Relapse is common (approximately 30%). Incomplete resection and malignant pleural effusion at diagnosis impact LTS negatively.