Role of Surgery in Stage IV Melanoma

Stage IV melanoma has a 5-year survival rate of 6%, but considerable advances have been made in systemic therapies. Systemic immunotherapy has achieved durable responses in up to 40% of patients, with similar improvements with targeted therapies. This has reshaped the landscape for surgery in stage IV melanoma. Metastasectomy can be considered in patients on systemic immunotherapy or targeted therapy with responding, stable, or isolated progressing lesions, oligometastatic disease, or long disease-free intervals. Surgery plays a role in providing tumor tissue for preparation of tumor-infiltrating lymphocytes for adoptive cell therapy. Surgical palliation plays a role in patients with symptomatic metastases.

Rationale for complete metastasectomy in patients with stage IV metastatic melanoma

Patients with stage IV melanoma have usually been treated with systemic therapies; however, the overall survival for patients with this approach is disappointing. A complete surgical resection of metastatic disease to stage IV sites offers the best chance to maximize survival. This review article will present data supporting the position that if a complete metastasectomy is technically feasible, then surgery should be strongly considered the first option for properly selected patients with stage IV melanoma.

Unique patterns of metastases in common and rare types of malignancy

This review on the unique patterns of metastases by common and rare types of cancer addresses regional lymphatic metastases but also demonstrates general principles by consideration of vital organ metastases. These general features of successfully treated metastases are relationships to basic biological behavior as illustrated by disease-free interval, organ-specific behavior, oligo-metastatic presentation, genetic control of the metastatic pattern, careful selection of patients for surgical resection, and the necessity of complete resection of the few patients eligible for long-term survival after resection of vital organ metastasis. Lymph node metastases, while illustrating these general features, are not related to overall survival because lymph node metastases themselves do not destroy a vital organ function, and therefore have no causal relationship to overall survival. When a cancer cell spreads to a regional lymph node, does it also simultaneously spread to the systemic site or sites? Alternatively, does the cancer spread to the regional lymph node first and then it subsequently spreads to the distant site(s) after an incubation period of growth in the lymph node? Of course, if the cancer is in its incubation stage in the lymph node, then removal of the lymph node in the majority of cases with cancer cells may be curative. The data from the sentinel lymph node era, particularly in melanoma and breast cancer, is consistent with the spectrum theory of cancer progression to the sentinel lymph node in the majority of cases prior to distant metastasis. Perhaps, different subsets of cancer may be better defined with relevant biomarkers so that mechanisms of metastasis can be more accurately defined on a molecular and genomic level.

Metastasectomy for stage IV melanoma: for whom and how much?

Although the conventional paradigm for treating metastatic melanoma relies on systemic therapies, a surgical approach should be strongly considered in selected patients. A surgical approach may not be appropriate for all patients, but it can offer a rapid clearance of disease without the toxicity of systemic therapy. Patient selection is of paramount importance for surgery to be effective. The rationale for surgical intervention in the management of metastatic melanoma, selection factors to be considered, published results, and future directions are discussed in this article.