What is the diagnosis and treatment for invasive melanoma (malignant melanoma)?

From the Guidelines

Invasive melanoma should be treated with wide local excision with margins of 1-2 cm, depending on the tumor's thickness and stage, as this approach has been shown to improve local control and melanoma-specific survival 1. The treatment of invasive melanoma typically involves surgical removal of the tumor with a margin of healthy tissue.

• The extent of surgery depends on the tumor's thickness and stage, with wider margins recommended for thicker tumors.
• For early-stage invasive melanoma, wide local excision with margins of 1-2 cm is usually sufficient, as supported by studies such as the one published in the Journal of the National Comprehensive Cancer Network 1.
• More advanced cases may require sentinel lymph node biopsy to check for spread, followed by complete lymph node dissection if positive.
• Systemic treatments like immunotherapy or targeted therapy are used for metastatic disease, as recommended by the NCCN guidelines 1.
• Regular follow-up with skin examinations, imaging studies, and blood tests is essential after treatment, as early detection and treatment significantly improve prognosis.
• The risk of invasive melanoma increases with sun exposure, fair skin, family history, and previous melanoma, making regular skin self-examinations and dermatologist visits important for high-risk individuals.
• A recent study published in JAMA in 2023 1 emphasizes the importance of screening for skin cancer and provides an overview of the treatment options for melanoma, including surgical excision, immunotherapy, and targeted therapy.

From the FDA Drug Label

YERVOY is a human cytotoxic T-lymphocyte antigen 4 (CTLA-4)-blocking antibody indicated for: Melanoma • Treatment of unresectable or metastatic melanoma in adults and pediatric patients 12 years and older as a single agent or in combination with nivolumab. • Adjuvant treatment of adult patients with cutaneous melanoma with pathologic involvement of regional lymph nodes of more than 1 mm who have undergone complete resection, including total lymphadenectomy.

The ipilimumab is indicated for the treatment of unresectable or metastatic melanoma in adults and pediatric patients 12 years and older as a single agent or in combination with nivolumab 2.

• Invasive melanoma is not explicitly mentioned, but unresectable or metastatic melanoma is, which may include invasive melanoma.
• The adjuvant treatment of adult patients with cutaneous melanoma with pathologic involvement of regional lymph nodes of more than 1 mm who have undergone complete resection, including total lymphadenectomy, is also indicated 2.

From the Research

Invasive Melanoma Treatment

• The main surgical treatment for invasive malignant melanoma consists of wide surgical excision and examination of the sentinel node, and in selected cases, complete lymph node dissection 3.
• A surgical excision margin of 1-2 cm is recommended for invasive melanoma, depending on the thickness of the melanoma 3, 4, 5.
• Sentinel node biopsy may be considered for patients with at least T1b melanomas, thickness 0.8 to 1.0 mm or less than 0.8 mm Breslow thickness with ulceration, classified as T1b lesion, per recent AJCC guidelines 3.
• Complete lymph node dissection has high morbidity and no impact on survival, and is restricted to regional control for clinically detected metastasis 3, 5.

Surgical Management

• Wide excision with 1-2 cm margins, depending on depth of the tumor, is the standard of care for surgical treatment of primary, invasive melanoma 4.
• Melanoma in situ requires 0.5-1 cm margins, with increasing evidence for 1 cm, particularly those presenting on the head-and-neck in the setting of chronic sun damage 5.
• Invasive melanomas need 1-2 cm margins, 2 cm for tumors thicker than 2 mm and some large tumors with >1-2 mm thickness and with a lentiginous growth pattern 5.

Adjuvant Treatment Options

• Dabrafenib and trametinib, alone and in combination, have been approved for use in BRAF-mutant metastatic melanoma, and have shown improved response rates and longer median progression-free survival compared to chemotherapy 6.
• Neoadjuvant pembrolizumab, dabrafenib, and trametinib in BRAFV600-mutant resectable melanoma have shown promising results, with a pathological response rate of 80% in the concurrent therapy arm 7.