Single-Stage excision and sentinel lymph node biopsy in selected patients with cutaneous melanoma: a monocentric retrospective cohort study

Standard surgery for invasive cutaneous melanoma involves diagnostic excision followed by wide local excision (WLE) and sentinel lymph node biopsy (SLNB), when indicated. In anatomically critical sites requiring complex reconstruction, a Single-Stage strategy combining WLE and SLNB may preserve native lymphatic drainage and reduce repeated procedures. We compared its long-term oncologic outcomes with conventional Two-Stage surgery. This retrospective, single-center cohort included 825 patients treated during 2013–2022: 49 underwent Single-Stage surgery for lesions highly suspicious for invasive melanoma on dermoscopy and reflectance confocal microscopy and requiring complex reconstruction, and 776 underwent Two-Stage surgery. Follow-up continued through December 2024. Recurrence-free survival (RFS) was assessed using Kaplan–Meier estimates, log-rank tests, and unadjusted Cox models; analyses by tumor thickness were exploratory. Single-Stage patients were older; median follow-up was approximately 50 months in both groups. All final margins were negative. Five-year RFS was 91.9% versus 79.4% for Single-Stage versus Two-Stage surgery (log-rank P = 0.037; unadjusted hazard ratio = 0.391; 95% confidence interval = 0.157–0.974). Corresponding estimates were 86.8% versus 64.7% for melanomas >2.0 mm thick (log-rank P = 0.038) and 100.0% versus 95.8% for melanomas ≤2.0 mm thick (log-rank P = 0.390). Disease-free status at the last assessment did not differ significantly overall or within either thickness stratum. Single-Stage surgery was feasible and showed a nominally significant association with higher RFS. These hypothesis-generating findings support Single-Stage surgery as a promising option for selected patients and warrant prospective multicenter validation.