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Excision
Source: Melanoma Treatment (PDQ®)–Health Professional Version, National Cancer Institute.
Source updated: May 2, 2025 · Captured 2026-09-09.
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Context: Treatment of Stage II Melanoma / Treatment Options for Stage II Melanoma
Evidence suggests that lesions no thicker than 2 mm (pT2b) may be treated conservatively with clinical radial excision margins of 1 cm to 2 cm. The decision to pursue a 1-cm versus 2-cm margin should be based on patient and lesion factors, including functional and cosmetic limitations. Evidence suggests that for melanomas measuring 2 mm or thicker (pT3a/b, pT4a/b), clinical radial margins of 2 cm are recommended. There is no evidence to support that a wider margin is beneficial.[1]
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Evidence (excision):
The Intergroup Melanoma Surgical Trial Task 2b compared 2-cm versus 4-cm margins for 740 patients with melanomas that were 1 mm to 4 mm thick.[2]
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The Intergroup Melanoma Surgical Trial Task 2b compared 2-cm versus 4-cm margins for 740 patients with melanomas that were 1 mm to 4 mm thick.[2]
With a median follow-up of more than 10 years, no significant difference in local recurrence or survival was observed between the two groups.
The Intergroup Melanoma Surgical Trial Task 2b compared 2-cm versus 4-cm margins for 740 patients with melanomas that were 1 mm to 4 mm thick.[2]
The reduction in margins from 4 cm to 2 cm was associated with a statistically significant reduction in the need for skin grafting (from 46% to 11%; P < .001).
A study conducted in the United Kingdom randomly assigned patients with melanomas thicker than 2 mm to undergo excision with either 1-cm or 3-cm margins.[3,4][Level of evidence A1]
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A study conducted in the United Kingdom randomly assigned patients with melanomas thicker than 2 mm to undergo excision with either 1-cm or 3-cm margins.[3,4][Level of evidence A1]
At a median follow-up of 5 years, patients who underwent excision with 1-cm margins had higher rates of locoregional recurrence (hazard ratio [HR], 1.34; 95% confidence interval [CI], 1.06–1.71; P = .02).
A study conducted in the United Kingdom randomly assigned patients with melanomas thicker than 2 mm to undergo excision with either 1-cm or 3-cm margins.[3,4][Level of evidence A1]
No difference in overall survival (OS) was seen (HR, 0.81; 95% CI, 0.58–1.13; P = .386) between the two groups. However, at 8.8 years, there was a melanoma-specific survival advantage for patients who underwent excision with 3-cm margins compared with 1-cm margins (HR, 1.24; 95% CI, 1.01–1.52; P = .036).
A study conducted in the United Kingdom randomly assigned patients with melanomas thicker than 2 mm to undergo excision with either 1-cm or 3-cm margins.[3,4][Level of evidence A1]
This study suggests that 1-cm margins may not be adequate for patients with melanomas thicker than 2 mm.
In a multicenter international trial (NCT03638492), the Swedish and Danish melanoma groups randomly assigned patients with localized cutaneous melanoma thicker than 2mm to undergo excision with clinical margins of either 2 cm (n = 471) or 4 cm (n = 465).[1][Level of evidence A1]
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In a multicenter international trial (NCT03638492), the Swedish and Danish melanoma groups randomly assigned patients with localized cutaneous melanoma thicker than 2mm to undergo excision with clinical margins of either 2 cm (n = 471) or 4 cm (n = 465).[1][Level of evidence A1]
With a median follow-up of 19.6 years, no significant difference in OS or melanoma-specific survival was observed between the two groups (HR, 0.98; 95% CI, 0.83–1.14; P = .75).
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