title: Pneumothorax as adverse event in patients with lung metastases of soft tissue sarcoma treated with pazopanib: a single reference centre case series.
abstract: BACKGROUND
  Recently, the phase III PALETTE study introduced pazopanib (Votrient®) as treatment for adult patients with locally advanced or metastatic non-liposarcoma soft tissue sarcoma after prior treatment with doxorubicin and/or ifosfamide. Pneumothorax was reported as adverse event in 8 of 246 treated patients (3.3%) in that study. This case series presents the incidence and clinic of this complication in the Leiden University Medical Centre.
  
  
  METHODS
  Forty-three patients were treated with pazopanib of which six patients (14.0%) developed a pneumothorax. These six patients were treated for malignant peripheral nerve sheath tumour, angiosarcoma, synovial sarcoma, fibromyxomatoid sarcoma, pleomorphic sarcoma and endometrial stromal sarcoma. All six patients had subpleural pulmonary or pleural metastases at the start of pazopanib and the pneumothorax developed during or shortly after treatment with pazopanib and was difficult to treat.
  
  
  CONCLUSIONS
  The incidence reported by us is higher than the incidence in the PALETTE study. Trials with pazopanib in renal cell carcinoma, urothelial carcinoma and cervix carcinoma did not report pneumothorax as an adverse event, suggesting pneumothorax as a specific adverse event in soft tissue sarcoma patients treated with pazopanib. This may be related to the fact that there is often pleural metastatic involvement and cystic degeneration due to pazopanib treatment may add to the risk.
  
  
  CONCLUSIONS
  The risk of an, often difficult to treat, pneumothorax during pazopanib therapy should be discussed with the patient before initiation of treatment for a pulmonary metastasized sarcoma and physicians should be alert to the occurrence of such an event.
authors.affiliation: Department of Clinical Oncology, Leiden University Medical Centre, Albinusdreef 2, Leiden, The Netherlands.
authors.forename: Arie J
authors.initials: AJ
authors.lastname: Verschoor
authors.affiliation: Department of Clinical Oncology, Leiden University Medical Centre, Albinusdreef 2, Leiden, The Netherlands.
authors.forename: Hans
authors.initials: H
authors.lastname: Gelderblom
keywords: Adverse event; Pazopanib; Pleural metastases; Pneumothorax; Pulmonary metastases; Soft tissue sarcoma