Locoregional Management of in-Transit Metastasis in Melanoma: An Ontario Health (Cancer Care Ontario) Clinical Practice Guideline

Objective: The purpose of this guideline is to provide guidance on appropriate management of satellite and in-transit metastasis (itm) from melanoma. Methods: The guideline was developed by the Program in Evidence-Based Care (pebc) of Ontario Health (Cancer Care Ontario) and the Melanoma Disease Site Group. Recommendations were drafted by a Working Group based on a systematic review of publications in the medline and embase databases. The document underwent patient- and caregiver-specific consultation and was circulated to the Melanoma Disease Site Group and the pebc Report Approval Panel for internal review; the revised document underwent external review. Recommendations: “Minimal itm” is defined as lesions in a location with limited spread (generally 1–4 lesions); the lesions are generally superficial, often clustered together, and surgically resectable. “Moderate itm” is defined as more than 5 lesions covering a wider area, or the rapid development (within weeks) of new in-transit lesions. “Maximal itm” is defined as large-volume disease with multiple (>15–20) 2–3 cm nodules or subcutaneous or deeper lesions over a wide area. (1) In patients presenting with minimal itm, complete surgical excision with negative pathologic margins is recommended. In addition to complete surgical resection, adjuvant treatment may be considered. (2) In patients presenting with moderate unresectable itm, consider using this approach for localized treatment: intralesional interleukin 2 or talimogene laherparepvec as 1st choice, topical diphenylcyclopropenone as 2nd choice, or radiation therapy as 3rd choice. Evidence is insufficient to recommend intralesional bacille Calmette– Guérin or CO₂ laser ablation outside of a research setting. (3) In patients presenting with maximal itm confined to an extremity, isolated limb perfusion, isolated limb infusion, or systemic therapy may be considered. In extremely select cases, amputation could be considered as a final option in patients without systemic disease after discussion at a multidisciplinary case conference. (4) In cases in which local, regional, or surgical treatments for itm might be ineffective or unable to be performed, or if a patient has systemic metastases at the same time, systemic therapy may be considered.