Grant: Project Grant

The incidence of melanoma is increasing worldwide. In 2019, 7800 Canadians will be diagnosed and 1300 will die from melanoma. Wide local excision (WLE) around the primary melanoma and a sentinel lymph node biopsy is standard treatment. The thickness (or depth) of the melanoma determines the extent of the WLE. Randomized trials to date have progressively confirmed the safety and effectiveness of reduced margins, but there is no randomized evidence comparing 1 versus 2cm margins for patients with clinical stage II melanoma. In Canada, this trial would affect 20% of all patients with melanoma or 1400 patients per year. With the current lack of randomized data, international guidelines suggest WLE margins of 1-3cm around a stage II melanoma. Such surgery results in a defect of 3-8cm (a result of a 1-3cm margin on either side of the melanoma which itself can be 1-2cm). In certain parts of the body where the skin is tight or there is less excess skin (e.g. mid-lower forearm, upper back or lower leg), this defect may need more extensive surgery such as a skin graft/skin flap to close the skin. Wider margins can increase morbidity, hospitalization rates, and recovery time and delay adjuvant systemic therapy. Patient groups emphasized the importance of minimizing disfigurement with surgery, wound discomfort, and time away from work, which may occur with narrower margins of excision. In a published pilot trial that compared 1cm vs 2cm margins and assessed feasibility for a larger trial, more patients in the 2cm margin group required complex reconstruction and had increased wound/skin breakdown. This melanoma margins trial is an international collaboration addressing the critical surgical question determined by national and international melanoma clinicians and Cochrane reviewers. It has strong support from patient advocacy groups in both Canada and worldwide, it is feasible, and results will potentially change current standard of care for stage II melanoma to a 1cm WLE.