From the Guidelines
Extramural vascular invasion (EMVI) can occur with melanoma metastasis to the colon, though it's uncommon, and treatment typically involves surgical resection when possible, along with systemic therapy such as immunotherapy (pembrolizumab, nivolumab) or targeted therapy (BRAF/MEK inhibitors) if the tumor has actionable mutations, as recommended by recent guidelines 1.
Melanoma Metastasis to the Colon
Melanoma can spread to the gastrointestinal tract, including the colon, and when it does, it can invade blood vessels outside the bowel wall, constituting EMVI. This typically represents advanced disease. Primary melanoma of the colon is extremely rare, but metastatic melanoma to the colon occurs in approximately 1-4% of melanoma patients.
Diagnosis and Treatment
When melanoma metastasizes to the colon, it can manifest as polypoid lesions, mass lesions, or infiltrative disease. Diagnosis requires colonoscopy with biopsy and immunohistochemical staining for melanoma markers like S100, HMB-45, and Melan-A.
Systemic Therapy
The presence of EMVI with metastatic melanoma in the colon generally indicates a poorer prognosis and higher risk of distant metastasis. Systemic therapy options include immunotherapy with pembrolizumab or nivolumab, which have shown efficacy in treating metastatic melanoma, including in patients with MSI-H tumors 1. Targeted therapy with BRAF/MEK inhibitors may also be considered if the tumor has actionable mutations.
Recent Guidelines
Recent guidelines recommend PD-1 blockade or PD-1 and ipilimumab as a standard of care for all patients with metastatic melanoma, regardless of their BRAF status, in the first-line setting 1. For BRAF-mutated disease, all the options available for WT melanoma are still valid, with the addition of BRAFis/MEKis if not used in the first-line setting.
- Key points:
- EMVI can occur with melanoma metastasis to the colon
- Treatment involves surgical resection and systemic therapy
- Immunotherapy with pembrolizumab or nivolumab is a recommended option
- Targeted therapy with BRAF/MEK inhibitors may be considered for tumors with actionable mutations
- Recent guidelines recommend PD-1 blockade or PD-1 and ipilimumab as a standard of care for all patients with metastatic melanoma 1
From the Research
Melanoma and Colon Cancer
- Melanoma is a type of skin cancer that can metastasize to other parts of the body, including the colon 2.
- The colon is not a common site for melanoma metastasis, but it can occur, and the prognosis is generally poor 2.
EMVI and Melanoma
- There is no direct evidence in the provided studies that discusses EMVI (extramural vascular invasion) in the context of melanoma in the colon.
- However, studies have shown that melanoma can metastasize to the colon and other parts of the gastrointestinal tract, and the presence of metastases can affect the prognosis and treatment options 2, 3.
Treatment Options
- Treatment options for melanoma that has metastasized to the colon may include surgery, immunotherapy, and targeted therapy 2, 4, 3, 5.
- The choice of treatment depends on various factors, including the stage and location of the metastases, the patient's overall health, and the presence of any genetic mutations 6, 4, 3, 5.