Trials Evaluating Surgical Margins in Melanoma

Historically, even thin melanomas were excised with very wide margins (3 to 5 cm):
- Studies have demonstrated, however, that narrower margins are often associated with the same recurrence rates as wider margins
The first randomized study involving surgical margins for melanomas less than 2 mm thick:
- Was reported by the WHO Melanoma Group Trial Number 10:
In an update of the study including 612 patients randomly assigned to a 1-cm or 3-cm margin of excision:
- There were no local recurrences:
  - Among patients with primary melanomas thinner than 1 mm
- There were four local recurrences among the 100 patients with melanomas 1 to 2 mm thick
  - All four occurred in patients with 1-cm margins
- There was no significant difference in survival:
  - Between the 1- and 3-cm surgical margin groups
- These results demonstrate that:
  - A 1-cm excision margin is safe for thin melanomas:
    - Less than 1 mm thick
A multi-institutional prospective randomized trial from France (French Cooperative Group Trial):
- Compared 2 cm and 5 cm excisional margins in 362 patients:
  - With melanomas less than 2 mm thick
- There were no differences in local recurrence rate or survival between the two groups
A randomized trial from Sweden (Swedish Melanoma Trial Group):
- Compared 989 melanomas patients with lesions less than 2 mm thick excised with 2- and 5-cm margins
  - The results were similar
In regard to thicker lesions:
- A randomized clinical trial from the United Kingdom:
  - The United Kingdom Melanoma Study Group (UKMSG) Trial:
    - Compared 1- and 3-cm excisional margins in 900 patients with melanomas at least 2 mm thick
      - With a median follow-up time of 60 months:
        
        A 1-cm margin was associated with a significantly increased risk of locoregional recurrence:
        
        37% vs. 32% for 3-cm margins
      - However, overall survival (OS) was similar in the two groups
For intermediate thickness lesions:
- A randomized prospective study conducted by the Intergroup Melanoma Committee:
  - Compared 2- and 4-cm radial margins of excision for 1- to 4-mm thickness melanomas
  - There was no difference in local recurrence rate between the two groups
  - 46% of patients in the 4-cm group required skin grafts:
    - Whereas only 11% of patients in the 2-cm group did (P < 0.001)
    - Of note, however, a trend for improved 10-year disease-specific survival was seen in 4-cm margins (77%) versus 2-cm margins (70%)
A clinical trial directly comparing 1- and 2-cm margins for 1- to 2-mm melanomas:
- Has not been performed
- Based upon data from the WHO Melanoma Group Number 10 Trial and the Intergroup Melanoma Trial:
  - 2-cm margins are recommended when the anatomic location is favorable and primary closure can be achieved
  - Since there is no demonstrable survival advantage for a 2-cm margin over a 1-cm margin in 1- to 2-mm melanomas:
    - A 1-cm margin can be justified in cases in which a 2-cm margin is not easily achievable