A Review of Contemporary Guidelines and Evidence for Wide Local Excision in Primary Cutaneous Melanoma Management

Abstract

Surgical wide local excision (WLE) remains the current standard of care for primary cutaneous melanoma. WLE is an elective procedure that aims to achieve locoregional disease control with minimal functional and cosmetic impairment. Despite several prospective randomised trials, the optimal extent of excision margin remains controversial, and this is reflected in the persistent lack of consensus in guidelines globally. Furthermore, there is now the added difficulty of interpreting existing trial data in the context of the evolving role of surgery in the management of melanoma, with our increased understanding of clinicopathologic and genomic prognostic markers leading to the often routine use of sentinel node biopsy (SNB) as a staging procedure, in addition to the development of adjuvant systemic therapies for high-risk disease. An ongoing trial, MelMarT-II, has been designed with the aim of achieving a definitive answer to guide this fundamental surgical decision.

Keywords: excision; margin; melanoma; recurrence; survival.

Figure 1

Wide local excision of a primary cutaneous melanoma. Following diagnostic excision, a larger area of tissue surrounding the scar (black dashed line) is excised (a), typically down to the level of the fascia using a wide local excision (green dashed line). The width of excision margin chosen (green arrow) is proportional to the Breslow thickness of the primary. Wide local excision aims to remove any local micrometastases or genetically abnormal cells (black outlines) that may still be harbored in the otherwise healthy tissue and/or the superficial lymphatics (brown) and that, if not removed with an adequate margin, may otherwise lead to a locoregional relapse (b), manifesting as an in-scar recurrence or in-transit metastases (black).