There is a lack of consensus regarding the optimal surgical excision margins for the management of primary cutaneous melanoma > 1 mm in Breslow thickness (BT). A narrower surgical margin is expected to be associated with lower morbidity, improved quality of life (QoL), and reduced cost, with no effect on survival outcomes. We report the results of an international pilot study (MelMarT) comparing 1 and 2-cm surgical excision margins for patients with primary melanoma > 1 mm in BT.
This phase III, multicentre trial [NCT02385214; ACTRN12614000667617] coordinated by the Australia and New Zealand Melanoma Trials Group (ANZMTG 03.12), randomised patients with a primary cutaneous melanoma > 1 mm in BT 1:1 to a 1 versus 2-cm wide excision margin to be performed with staging sentinel lymph node biopsy. Surgical closure technique was at the discretion of the treating surgeon. Patients’ QoL was measured (FACT-M, PainDetect, EQ-5D-5L questionnaires) at baseline, and 3, 6, and 12 months after randomisation.
Between January 2015 and June 2016, 400 patients were randomised from 19 centres in 5 countries. A total of 377 patients were available for analysis. Primary melanomas were located on the trunk (56.9%), extremities (35.6%), and head and neck (7.4%). More patients in the 2-cm margin group required reconstruction (34.9 vs. 13.6%; p < 0.0001). There was an increased wound necrosis rate in the 2-cm arm (3.6% v 0.5% p = 0.036). After 12 months of follow-up, no differences were noted in QoL between groups.
This pilot study demonstrates the feasibility of a large international randomised controlled trial to provide a definitive answer to the question of the optimal surgical excision margins for patients with intermediate- to high-risk primary cutaneous melanoma. A full cohort of 2,998 patients (ANZMTG 04.18 MelMarT-II) will be required to demonstrate non inferiority of a 1-cm margin.