In a nutshell
This study evaluated the effectiveness of 2 cm versus 4 cm excision margins for patients with thick melanomas on the surface of the skin (cutaneous). This study concluded that a 2-cm excision margin was safe for these patients.
The primary treatment for all stages of melanoma is surgery to remove the tumor. This involves cutting out the tumor (excision) and some of the healthy tissue around it. This extra tissue removal is called an excision margin. The smaller the excision margin, the lower the risk of complications after surgery. Currently, 2-cm margins are recommended for tumors that are thicker than 2 mm.
Studies have also shown that smaller margins may be associated with a risk of cancer recurrence, while larger margins can lead to skin defects. The amount of healthy tissue removed should be balanced with the risk of long-term complications. Whether 2-cm margins are as safe as 4-cm margins for patients with thick melanomas is unclear.
Methods & findings
This study had 936 patients with thick (2 mm or more) cutaneous melanoma. Patients had surgery to remove the tumor. Patients were randomly divided into two groups based on how much healthy tissue around the tumor was removed (either 2 cm or 4 cm). 465 patients had a 2-cm margin, and 471 patients had a 4-cm margin. Patients were followed-up for an average of 19.6 years.
Overall, slightly more patients in the 4-cm margin group succumbed to their disease during follow-up compared to the 2-cm margin group (51% vs. 49%). However, mortality risk was the highest during the first 5 years of follow-up (36%, 4-cm group vs. 35%, 2-cm group).
A 2-cm excision margin slightly decreased mortality risk by 4% compared to a 4-cm margin. However, having a tumor thicker than 3 mm was significantly associated with a 45% higher mortality risk compared to thinner tumors (3 mm or smaller). Tumors found on the trunk were also significantly associated with a 20% higher mortality risk compared to tumors found elsewhere.
The bottom line
This study concluded that a 2-cm excision margin was just as safe as a 4-cm excision margin for the removal of thick melanomas on the surface of the skin.
The fine print
This study only looked at melanoma localized to small areas of the skin. Patients with melanoma that spread to other parts of the body were not included. More studies are needed to confirm these results.
Published By :
Lancet (London, England)
Jul 04, 2019