TOPLINE:

In a retrospective cohort of patients with melanoma in situ (MIS) with non-lentigo maligna/non-acral lentiginous (non-LM/non-ALM) subtypes, no local recurrences, metastases, or melanoma-specific deaths occurred when excisional biopsy margins were clear, regardless of subsequent wide-excision status.

METHODOLOGY:

• Researchers conducted a retrospective cohort study involving 401 patients (median age, 52 years; 53.4% women) with 403 non-LM/non-ALM MIS at the Skin Cancer and Melanoma Unit of Andreas Sygros University Hospital in Athens, Greece, from 1991 to 2023.
• Most patients were immunocompetent (98.5%). The median maximum diameter of MIS on the histopathological report was 0.7 cm.
• The most common site of MIS was the trunk (49.9%), followed by the lower extremity (24.6%), upper extremity (17.6%), and head and neck (7.9%).
• All patients underwent an initial excisional biopsy, with clear margins in 97.9% of the cases; most (92.3%) also had wide excision.
• The study outcomes were local recurrence, metastasis, and melanoma-specific survival.

TAKEAWAY:

• Only one local recurrence occurred in a patient with involved margins at excisional biopsy who did not undergo wide excision and developed invasive melanoma at a follow-up of 14 months.
• The remaining 30 patients who did not undergo wide excision showed no recurrence at a median follow-up of 8.1 years; of these, 26 had a clear margin, and margin status was missing in four patients.
• In 23 patients with 23 lesions treated with wide excision having margins narrower than the standard 0.5 cm (mean margin size, 0.36 cm), there were no recurrences at a median follow-up of 4.3 years.
• No patient experienced metastasis or melanoma-specific death during the follow-up period.

IN PRACTICE:

While results need to be confirmed with further studies, this study found “no local recurrences, metastases, or melanoma-specific deaths in 401 patients with non-LM/non-ALM MIS,” providing support “that non-LM/non-ALM MIS excised with clear histopathological margins in the excisional biopsy may not require additional treatment,” the study authors wrote. “Decreasing overtreatment through de-escalation of surgery is one element in a multipronged approach that is needed to tackle melanoma in situ overdiagnosis and overtreatment,” Katy J.L. Bell, PhD, University of Sydney, Sydney, Australia, and coauthors wrote in an accompanying editorial.

SOURCE:

The study was led by Clio Dessinioti, MD, First Department of Dermatology-Venereology, National and Kapodistrian University of Athens, Andreas Sygros Hospital. The study and editorial were published online on September 3 in JAMA Dermatology.

LIMITATIONS:

The study was retrospective, involved one center, and covered 32 years, during which time diagnostic standards evolved. Margin sizes were inferred from pathology reports, and tissue shrinkage could have led to slight underestimation. 

DISCLOSURES:

The authors did not report any funding information. One author reported receiving financial support, grants, and research fees, honoraria from Regeneron, Novartis, Leo Pharma, Merck Sharp & Dohme, Roche, Genesis Pharma, Janssen-Cilag, and AbbVie unrelated to this work. The editorialists reported receiving grants and consulting fees from the Australian National Health and Medical Research Council and Canfield Scientific and holding patents and stocks in MoleMap NZ, e-derm-consult GesmbH, and Trajan Scientific and Medical via Uniquest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.