Wider Surgical Margin Linked To Improved Melanoma-Specific Survival

A 3 cm margin of excision could lead to improved disease-specific survival in patients with primary, cutaneous melanoma of at least 2 mm in thickness

medwireNews: A wide excision may reduce long-term disease-specific mortality in patients with a high-risk primary cutaneous melanoma of 2 mm or greater in Breslow thickness on the trunk or limbs, indicates research published in The Lancet Oncology.

After a median of 8.8 years, melanoma-specific survival was significantly worse in the 453 patients who were randomly assigned to undergo surgery with a 1 cm margin than in those with a 3 cm margin, with 194 versus 165 deaths attributed to the disease, giving a hazard ratio of 1.24.

The 1 cm margin group also had a greater number of deaths overall than the 3 cm group, at 253 versus 241, although the hazard ratio of 1.14 did not reach significance.

“This study, alongside the other randomised trials, reiterates current international guidelines stating that a 1 cm margin is inadequate for the treatment of a melanoma greater than 2 mm in Breslow thickness”, say Andrew Hayes, from The Royal Marsden Hospital National Health Foundation Trust in London, UK, and co-authors.

“It lends support to further investigation of the adequacy of a 1 cm margin for melanomas between 1 mm and 2 mm in thickness, especially those with other poor prognostic features, for which most international guidelines at present still advise a 1 cm excision.”

However, the researchers admit that, as earlier research into thick melanomas suggests that a 4 cm margin does not offer better melanoma-specific survival than a 2 cm margin, it may be unnecessary to extend past 2 cm.

Marc Moncrieff, from Norfolk and Norwich University Hospital in the UK, writes in an accompanying comment that the study findings may indicate that a 1 cm margin is not wide enough to remove melanoma microsatellite disease, known to be associated with a poor prognosis.

Hypothesising that patients who experience local or regional recurrence might encompass a small subgroup with a high-risk tumour phenotype, he writes: “Accordingly, clinicians' efforts might be supported by the identification of biomarkers to recognise the high-risk minority of patients, especially those with a microscopic locoregional extension at the time of diagnosis of their primary melanoma.

“These patients might benefit from a wider, elective excision margin for their melanoma, or indeed, adjuvant therapies that might become the standard of care in the near future.”

References

Hayes AJ, Maynard L, Coombes G, et al. Wide versus narrow excision margins for high-risk, primary cutaneous melanomas: long-term follow-up of survival in a randomised trial. Lancet Oncol 2016; Advance online publication 11 January. DOI: http://dx.doi.org/10.1016/S1470-2045(15)00482-9

Moncrieff M. Excision margins for melanomas: how wide is enough? Lancet Oncol 2016; Advance online publication 11 January. DOI: http://dx.doi.org/10.1016/S1470-2045(15)00556-2

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