Sentinel lymph node dissection in primary melanoma reduces subsequent regional lymph node metastasis as well as distant metastasis after nodal involvement.

Background: In many countries sentinel lymph node dissection (SLND) followed by complete lymphadenectomy if positive is routinely performed treatment for primary cutaneous melanoma. However, the potential survival benefit of SLND is still controversial.

Methods: Patients with primary cutaneous melanoma (tumor thickness 1.00 mm or greater) diagnosed in the Department of Dermatology, University of Tuebingen, Germany between 1991 and 2000 were included in the study. A total of 439 patients who received SLND were compared retrospectively with 440 patients without SLND with regards to occurring patterns of metastases and disease-free and overall survival. SLND-positive cases and SLND-negative patients with subsequent development of regional lymph node metastasis (SLND-LN+) were compared with non-SLND patients who had developed regional lymph node metastasis (non-SLND-LN+).

Results: Regional lymph node metastases as the first recurrence occurred more frequently in the non-SLND collective (16.5%) compared with the SLND group (7.3%; P = 0.001), whereas satellite/in-transit metastases and distant metastases did not differ. Driven by the reduction of regional lymph node metastases, disease-free survival was improved in the SLND collective (P = 0.003). No significant difference in overall survival was observed (P = 0.090).The risk of dying from melanoma was 2.2 times higher in the non-SLND-LN+ group than in the SLND-LN+ group (P = 0.009), while the risk of developing distant metastasis was 2.3 times higher (P = 0.002).

Conclusions: SLND reduced subsequent regional lymph node metastases and improved disease-free survival, while overall survival remained unaffected. SLND reduced distant metastases and improved overall survival in the subgroups of patients with regional lymph node involvement.