What are the local treatment recommendations for cancer on the toe?

Local Treatment Recommendations for Cancer on the Toe

Primary Treatment Approach

For malignant tumors on the toe, surgical excision with adequate margins is the standard treatment, with the specific approach depending on tumor type, thickness, and invasiveness. 1

Treatment by Tumor Type

Melanoma of the Toe (Subungual/Periungual)

Amputation at the distal phalanx with a margin of normal-appearing skin is the recommended approach for subungual melanoma. 1

• Surgical margins should be based on Breslow thickness:

  • Melanoma in situ: 0.5 cm margins 1, 2
  • Melanomas 1-2 mm thick: 1-2 cm margins 2
  • Melanomas 2-4 mm thick: 2 cm margins 2
  • Melanomas >4 mm thick: 2-3 cm margins 2

• Level of amputation considerations:

  • Traditional recommendation: distal interphalangeal joint for fingers, metatarsophalangeal joint for toes 1
  • More conservative approach: amputation of distal phalanx with margin of normal skin shows equivalent outcomes 1
  • Functional surgery (partial distal phalanx resection) shows no difference in recurrence-free survival compared to proximal amputation 1

Important caveat: Nail bed excision with skin grafting typically yields suboptimal functional results with persistent sensitivity and pain issues, whereas distal phalangeal amputation is generally well-tolerated. 1

Soft Tissue Sarcomas of the Toe

Limb-sparing surgery with wide local excision is the preferred approach over radical amputation for soft tissue sarcomas of the hand and foot. 1, 3

• Surgical margin requirements:

  • Resection margin of ≥1 cm is associated with 0% local recurrence 1
  • Margins <1 cm are associated with 13% local recurrence rate 1
  • Re-excision to achieve microscopically negative margins achieves 88% 10-year local recurrence-free survival 3

• Radiation therapy indications:

  • Adjuvant radiation improves local control when re-excision with negative margins is not achieved 3
  • Radiation does not improve local control when definitive re-excision achieves negative margins 3
  • Postoperative radiation: 60-66 Gy in 1.8-2 Gy fractions 1
  • Preoperative radiation: 50-50.4 Gy in 1.8-2 Gy fractions 1

Critical point: Radical amputation as initial treatment does not decrease regional metastasis probability and does not improve disease-specific survival. 1, 3

Specific Soft Tissue Sarcoma Subtypes

Dermatofibrosarcoma protuberans (DFSP) on the toe:

• Wide local excision with 3 cm margins is standard 4
• Alternative options: partial or total toe amputation after primary excision 5
• Mohs micrographic surgery may be treatment of choice when tissue conservation is critical 4

Cutaneous leiomyosarcoma:

• Wide local excision with 3-5 cm margin and removal of underlying subcutaneous tissue 4
• Mohs micrographic surgery has shown good success in small case series 4

Advanced Techniques for Limb Preservation

Isolated Limb Perfusion (ILP)

ILP should be considered for locally advanced sarcomas where limb preservation may not otherwise be possible, but only at specialized centers. 1, 6

• ILP employs high-dose chemotherapy plus tumor necrosis factor-alpha and hyperthermia 1
• Achieves tumor shrinkage rendering tumors operable by marginal resection with excellent local control 1
• Complete response rates of 58% with low toxicity when leakage is controlled (<1%) 6
• Particularly important for local recurrence in post-radiotherapy settings where further radiation cannot be delivered 1

Angiosarcoma of the extremities shows very high complete response rates to ILP with durable responses. 1

When Amputation is Necessary

Amputation should be reserved only for cases where surgical excision or re-excision with adequate margins cannot be performed without sacrificing functionally significant neurovascular or osseous structures. 1, 3

Follow-up Surveillance

• Regular clinical examination is the primary surveillance strategy 2
• Baseline radiologic imaging is not recommended for asymptomatic patients with clinically node-negative disease 2
• Imaging should only be performed to evaluate specific signs or symptoms of potential metastasis 2
• For melanoma: ultrasound of regional lymph node basin should be considered if sentinel lymph node biopsy criteria are met but procedure not performed 2

Common Pitfalls to Avoid

• Do not perform immediate radical amputation without attempting limb-sparing surgery first, as it does not improve survival 3
• Do not use radiation as a substitute for suboptimal surgical resection—re-resection may be necessary 1
• Do not perform nail bed excision with skin grafting for subungual melanoma due to poor functional outcomes 1
• Do not add postoperative radiation boost for positive margins after preoperative radiation, as this is unlikely to be beneficial and may cause excess late toxicity 1