The optimum excision margin and regional node management for primary cutaneous T3 melanomas (2-4 mm in Thickness): a retrospective study of 1587 patients treated at a single center.

OBJECTIVE: To determine the optimum excision margin and nodal management for patients with primary cutaneous melanomas 2.01- to 4.00-mm thick (T3 melanomas).

BACKGROUND: Currently available evidence does not reliably define the minimum safe excision margin and best nodal management for patients with primary cutaneous T3 melanomas.

METHODS: A retrospective study was conducted, analyzing data on 1587 patients with melanomas 2.01- to 4.00-mm thick treated at a single center.

RESULTS: A histopathologic excision margin of 8 mm or more (equivalent to a ≥1 cm surgical margin) was associated with increased local and in-transit recurrence-free survival [hazard ratio (HR) = 0.54; P = 0.008] and disease-free survival (DFS) (HR = 0.59; P = 0.001) compared with a less than 8-mm margin. The <8-mm group had reduced distant recurrence-free survival (DRFS) compared with the 8- to 16-mm group (HR = 1.63; P = 0.038). On multivariate analysis, patients with a positive sentinel lymph node (SLN) had significantly reduced melanoma-specific survival (MSS), DFS, regional node recurrence-free survival (RNRFS) and DRFS compared with patients with a negative SLN, unless an immediate completion lymph node dissection was performed. Patients in whom an SLN biopsy was not performed had significantly reduced MSS (HR = 2.10; P < 0.001), DFS (P < 0.001), RNRFS (P < 0.001), and DRFS (P = 0.010) compared with patients who received an SLN biopsy.

CONCLUSIONS: A histopathologic excision margin of 8 mm or more (corresponding to a ≥1 cm surgical excision margin) combined with SLN biopsy (followed by an immediate completion lymph node dissection if positive) provided T3 melanoma patients with optimum local, regional, and distant disease control and resulted in enhanced melanoma-specific survival.