What are the National Comprehensive Cancer Network (NCCN) guidelines for Dermatofibrosarcoma protuberans (DFSP)?

From the Guidelines

The NCCN guidelines for Dermatofibrosarcoma Protuberans (DFSP) primarily recommend wide local excision with negative margins as the first-line treatment, with a goal of achieving clear margins to minimize recurrence, as stated in the most recent guidelines 1. The recommended surgical margin is typically 2-4 cm of normal tissue from the gross tumor edge, including subcutaneous fat and fascia. For cases where wide excision is not feasible or would result in excessive morbidity, Mohs micrographic surgery is an alternative, allowing for complete margin assessment while preserving healthy tissue 1.

Key Considerations

• If negative margins cannot be achieved or in cases of recurrent or metastatic disease, targeted therapy with imatinib (400-800 mg daily) is recommended, as it targets the COL1A1-PDGFB fusion protein present in most DFSP cases 1.
• Radiation therapy may be considered as an adjuvant treatment in cases with positive margins where further surgery is not possible, or in inoperable cases, with typical doses ranging from 50-60 Gy.
• Regular follow-up is crucial, with physical exams every 6-12 months for 5 years, then annually, and imaging studies are not routinely recommended unless there are specific concerns for recurrence or metastasis.

Multidisciplinary Approach

• The guidelines emphasize a multidisciplinary approach, involving dermatologists, surgical oncologists, radiation oncologists, and medical oncologists to ensure optimal patient care, as highlighted in the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Dermatofibrosarcoma Protuberans, Version 1.2025 1.

Important Recommendations

• Neoadjuvant imatinib can be considered for patients in whom DFSP resection with negative margins may result in unacceptable functional or cosmetic outcomes 1.
• Tumor mutation analysis and neoadjuvant imatinib can be considered options for unresectable or borderline resectable disease.
• If a negative margin is achieved, no adjuvant treatment is necessary, as recommended by the NCCN panel 1.

From the Research

National Comprehensive Cancer Network (NCCN) Guidelines for Dermatofibrosarcoma Protuberans (DFSP)

• The NCCN guidelines for DFSP recommend complete surgical excision as the standard treatment 2
• The surgical procedures include:
  • Wide local excision (WLE) with tumor-free margins
  • Mohs micrographic surgery (MMS)
  • Amputation (in rare cases)
• The guidelines also suggest that unresectable DFSPs can be treated with radiation therapy and/or targeted therapy 2

Surgical Margin Width

• The optimal surgical margin width for DFSP is still a topic of debate
• Studies have shown that a margin width of 1-2 cm can be sufficient to achieve negative margins and low recurrence rates 3, 4
• A study using the vertical modified technique (VMT) found that reducing surgical margins did not increase the risk of recurrence 5
• Another study compared WLE with Mohs Tubingen technique and found that the micrographic technique preserved a significant amount of healthy tissue (69.15%) while achieving similar recurrence rates 6

Treatment Approaches

• WLE with total peripheral margin pathologic evaluation has been shown to be effective in achieving low recurrence rates (1%) with relatively narrow margins (median 2 cm) 3
• MMS and its variants, such as the Tubingen torte technique, are considered safe and tissue-sparing techniques for the treatment of DFSP 6
• Radiation therapy and targeted therapy can be used to treat unresectable DFSPs or in cases where surgical excision is not possible 2