What are the treatment options for melanoma based on Breslow (tumor thickness) depth?

Treatment Options for Melanoma Based on Breslow Depth

The treatment of melanoma is primarily surgical, with excision margins determined by the Breslow depth (tumor thickness), ranging from 0.5 cm for melanoma in situ to 3 cm for melanomas >4 mm thick. 1

Surgical Excision Margins by Breslow Depth

• For melanoma in situ (non-invasive): 0.5 cm margin 2, 1
• For thin melanomas (≤1 mm Breslow thickness): 1 cm margin 2, 1
• For intermediate melanomas (>1 mm to ≤2 mm): 1-2 cm margin 2, 1
• For thick melanomas (>2 mm to ≤4 mm): 2 cm margin 2, 1
• For very thick melanomas (>4 mm): 3 cm margin 2, 3

Sentinel Lymph Node Biopsy (SLNB) Recommendations

• Not recommended for melanomas <0.8 mm without ulceration 4
• May be considered for thin melanomas 0.8-1.0 mm or <0.8 mm with ulceration (T1b) after thorough discussion of risks and benefits 4, 5
• Recommended for intermediate-thickness melanomas (1.0-4.0 mm) 2, 4, 6
• May be recommended for thick melanomas (>4.0 mm) after discussion of risks and benefits 4, 6
• Should be performed only by skilled teams in experienced centers 2

Management of Regional Lymph Nodes

• Routine elective lymphadenectomy is not recommended for localized melanoma 2
• Complete lymph node dissection is indicated if sentinel node is positive for micrometastases 2
• For patients with clinically evident regional node involvement, surgical dissection of involved nodes is the standard treatment 2, 3
• After complete nodal dissection, there is no indication for further treatment in most cases 2

Special Considerations

• In anatomically sensitive locations (face, distal extremities), margins may need modification to accommodate anatomic or cosmetic considerations 1, 7
• For lentigo maligna melanoma with inadequate margins, radiotherapy may be considered when re-excision is not feasible 2
• In cases of tumor regression, excision margins should be those for lesions in the category immediately above the actual thickness 2

Adjuvant Therapy

• No generally accepted adjuvant therapy exists for high-risk primary melanoma or completely resected lymph node metastases 2
• Adjuvant interferon-α has shown significant prolongation of disease-free survival in some trials, with positive effects on overall survival in two out of three randomized trials 2
• Adjuvant chemotherapy, hormone therapy, mistletoe extracts, and viscum album have not shown benefit and should not be used outside clinical trials 2
• Radiotherapy may be an option in cases of incomplete nodal clearance (fixed nodes, extensive invasion, capsular disruption) 2

Common Pitfalls to Avoid

• Using inadequate margins for melanoma, particularly for thick melanomas, which can lead to higher rates of local recurrence and melanoma-specific mortality 1, 3
• Overlooking tumor regression, which may lead to inadequate margins 2, 1
• Performing routine nodal dissection after excision of isolated cutaneous melanoma, which is not recommended and associated with significant morbidity 2
• Relying on clinical/surgical margins without careful pathological assessment 1

The management of melanoma requires a systematic approach based on tumor thickness, with surgical excision as the cornerstone of treatment and consideration of sentinel lymph node biopsy for appropriate staging.