FUNCTIONAL surgery may reduce the risk of recurrence in patients with nail unit melanoma with a Breslow thickness lower than 0.8 mm, according to new data. Author Byung Ho Oh, Yonsei University College of Medicine, Seoul, South Korea, and colleagues, explained that while functional surgery, instead of amputation, is a treatment option for minimally invasive nail unit melanoma, its indications need clarification.
The team conducted a retrospective review, which analysed data of 140 patients with nail unit melanoma, including 107 patients who underwent functional surgery and 33 patients who underwent amputation at a tertiary referral centre in 2008–2022. The research team then assessed the optimal cut-off points of Breslow thickness for stratifying recurrence risk. In the amputation group, thickness values were 3.14 mm±2.62 mm, while in the functional surgery group they were 0.70 mm±1.36 mm. Mean follow-up was of 3.97±3.19 years for the amputation group, and 3.90±2.62 years for the functional surgery group.
The data showed a recurrence rate of 30.3% in the amputation group compared to 21.5% in the functional surgery group. Furthermore, 5-year recurrence-free survival rates were of 57.9% (95% confidence interval [CI]: 40.2–83.4%) in the amputation group compared to 74.8% (95% CI: 65.5–85.4%) in the functional surgery group. The team also a noted distant disease rate of 30.3% in the amputation group versus 7.48% in the functional surgery group, as well as a 5-year distant-disease-free survival rate of 57.9% (95% CI: 40.2%-83.4%) in the amputation group versus 88.8% (95% CI: 81.6–96.7%) in the functional surgery group. Factors associated with recurrence or distant disease were also demonstrated, which included greater Breslow thickness, male sex, amelanotic colour, ulcers, and nodules.
The team concluded that the optimal cut-off for stratifying recurrence risk was a Breslow thickness of 0.88 mm. “Functional surgery is suggested for nail unit melanoma without amelanotic colour, nodules and ulcers,” they wrote. “However, nail unit melanoma with [at least] 0.8 mm invasion depth shows greater recurrence risk after functional surgery.” Limitations of the study include the small sample size.