What is the primary treatment for a solitary fibrous tumor?

Primary Treatment for Solitary Fibrous Tumor

Complete surgical resection with negative margins is the standard treatment and best chance for cure for solitary fibrous tumors (SFTs). 1

Surgical Approach

The surgical strategy should be tailored based on tumor location and characteristics:

• En bloc resection is the goal, removing the tumor in one piece with a rim of normal tissue 1
• Negative margins are critical for reducing recurrence risk 2
• For retroperitoneal SFTs:
  • Complete resection with negative margins while preserving uninvolved organs 1
  • Consider the tumor's sensitivity to radiotherapy during preoperative planning 1

Anatomical Considerations

Different locations require specialized surgical approaches:

• Pleural SFTs: Complete resection via thoracotomy with full lung expansion post-procedure 3
• Mesenteric/Abdominal SFTs: En bloc resection with clear margins 4
• Uterine SFTs: Complete surgical excision with clear margins 5
• Hepatic SFTs: Resection via appropriate hepatectomy when liver involvement is present 6

Risk Stratification

Several factors predict more aggressive behavior and should guide treatment intensity:

• Size > 10 cm
• Presence of histologically malignant component
• Positive surgical margins

These factors are associated with worse metastasis-free survival and may warrant more aggressive management 2.

Adjuvant Therapy

For standard SFTs with complete resection and negative margins, adjuvant therapy is not routinely recommended. However, consider additional treatments in specific scenarios:

• Radiotherapy:

  • May reduce recurrence risk after incomplete surgical resection 1
  • Should be considered for SFTs due to their known radiosensitivity 1
  • Delivered using advanced techniques like IMRT and IGRT when indicated 1

• Systemic therapy for malignant, unresectable, or recurrent disease:

  • Anthracycline-based regimens are standard first-line treatment 1
  • Multi-agent chemotherapy with anthracyclines plus ifosfamide may be considered for better response rates 1
  • Targeted therapies may be considered in specific cases 3

Follow-up

Close post-operative surveillance is essential to identify early recurrent disease, particularly for:

• Tumors with positive margins
• Tumors larger than 10 cm
• Tumors with malignant histological features 2

Pitfalls and Caveats

• Incomplete resection: Grossly incomplete resection is of questionable benefit and potentially harmful 1
• Misdiagnosis: Ensure proper immunohistochemical analysis to confirm diagnosis and exclude other entities 5
• Underestimating recurrence risk: Even with complete resection, SFTs can recur, especially those with malignant features or positive margins 2
• Extrathoracic SFTs: Have a slightly higher risk of local recurrence compared to thoracic SFTs and require vigilant follow-up 2

In summary, complete surgical resection with negative margins remains the cornerstone of SFT treatment, with adjuvant therapies reserved for high-risk or incompletely resected tumors.