Updated evidence‐based clinical practice guidelines for the diagnosis and management of melanoma: definitive excision margins for primary cutaneous melanoma

Abstract

Introduction: Definitive management of primary cutaneous melanoma consists of surgical excision of the melanoma with the aim of curing the patient. The melanoma is widely excised together with a safety margin of surrounding skin and subcutaneous tissue, after the diagnosis and Breslow thickness have been established by histological assessment of the initial excision biopsy specimen. Sentinel lymph node biopsy should be discussed for melanomas ≥ 1 mm thickness (≥ 0.8 mm if other high risk features) in which case lymphoscintigraphy must be performed before wider excision of the primary melanoma site. The 2008 evidence‐based clinical practice guidelines for the management of melanoma (http://www.cancer.org.au/content/pdf/HealthProfessionals/ClinicalGuidelines/ClinicalPracticeGuidelines-ManagementofMelanoma.pdf) are currently being revised and updated in a staged process by a multidisciplinary working party established by Cancer Council Australia. The guidelines for definitive excision margins for primary melanomas have been revised as part of this process. Main recommendations: The recommendations for definitive wide local excision of primary cutaneous melanoma are: melanoma in situ: 5–10 mm margins invasive melanoma (pT1) ≤ 1.0 mm thick: 1 cm margins invasive melanoma (pT2) 1.01–2.00 mm thick: 1–2 cm margins invasive melanoma (pT3) 2.01–4.00 mm thick: 1–2 cm margins invasive melanoma (pT4) > 4.0 mm thick: 2 cm margins Changes in management as a result of the guideline: Based on currently available evidence, excision margins for invasive melanoma have been left unchanged compared with the 2008 guidelines. However, melanoma in situ should be excised with 5–10 mm margins, with the aim of achieving complete histological clearance. Minimum clearances from all margins should be assessed and stated. Consideration should be given to further excision if necessary; positive or close histological margins are unacceptable.

Epidemiology of melanoma in rural southern Queensland

“…Such management in public facilities from these communities requires patient travel from 1 to 3 hours by road. Cases not transferred for whom management might be expected to include referral for further evaluation of nodal spread (>1 mm depth) and were older patients (median age 79 years) half of whom had high‐grade nodular melanoma (n = 13). Along with depth, these are two major negative influential determinants for melanoma survival .…”

Log margin‐to‐thickness ratio improves disease‐specific survival prediction in oral cancer: A single cancer centre database

“…Determining adequate resection margin by examining tumour thickness has been the subject of numerous studies on the treatment of melanoma. The recommended margin for melanoma <1 mm was 10 mm, 1‐2 mm was 10‐20 mm and >20 mm was >2 mm . Sawabata et al also suggested that a margin to tumour size ratio greater than one in pulmonary excision of peripheral non–small cell lung cancer that obtained a negative malignant margin was associated with a favourable 5‐year survival rate.…”

“…The recommended margin for melanoma <1 mm was 10 mm, 1-2 mm was 10-20 mm and >20 mm was >2 mm. 20 Sawabata et al 21…”

Reflectance confocal microscopy margin mapping and monitoring of an amelanotic melanoma in situ of the ear

“…Surgical excision remains the recommended standard for treatment of melanoma in situ with minimum margins of 5-10 mm. 8 In order to achieve such margins, lesions must be distinguishable from the background skin to excise with appropriate clearance. By employing RCM, an in vivo assessment can be made to help guide density and degree of cytological atypia of the proliferation of melanocytic cells in order to guide treatment margins.…”