Current standards of care for melanoma excision in Australasia

It was with some concern that we read the letter by Tejera-Vaquerizo et al. published in the Journal of Primary Health Care on 19 July 2019 advocating excision of lesions suspected as being melanoma in situ with a 10 mm margin as opposed to the currently advised 2 mm margin.¹

The clinical guidelines for the management of melanoma in Australia have recently been updated and published in wiki form. The panel of experts saw no reason to alter the recommendation for initial excisional biopsy with a 2 mm peripheral margin.²

While we accept the authors’ statements regarding sentinel lymph node biopsy (SLNB), this is now becoming primarily a staging procedure with a positive sentinel node upgrading the disease to anatomical stage III.

Subsequent to the KEYNOTE-054 study,³ Pembrolizomab is now registered in New Zealand for the adjuvant treatment of patients with melanoma with lymph node involvement who have undergone complete resection. Accordingly, we contend that the accuracy of SLNB remains paramount.

The new guidelines now recommend 5–10 mm margins for melanoma in situ. While this would appear to favour the authors’ suggested approach, for GPs in Australia and New Zealand with a particular interest in skin cancer, data show that 5.59 lesions are excised with the intention to exclude or confirm melanoma for each melanoma diagnosed.⁴ Other studies show that this number varies widely, ranging from 2.2 to 30.5, with a figure of 14.6 for Australian primary care practitoners.⁵

Initial excision of suspected melanoma in situ with 10 mm margins would result in many benign lesions being excised with unnecessarily wide defects, longer scars, more tension on wounds and higher risk of complications.

The authors suggest 10 mm margins in ‘suitable anatomic sites’. As this is subjective, adoption of this policy would result in uncertainty, inconsistency and possible confusion for GPs.

We strongly recommend that GPs excising lesions suspected of being melanoma continue to follow the established guidelines and do so with a 2 mm clinical margin.

This research did not receive any specific funding.

The authors declare no conflicts of interest.