Recurrence factors in patients with cutaneous melanoma and positive sentinel lymph node treated in a single reference unit in Buenos Aires.

Introduction: Although therapeutic advances have improved results of cutaneous melanoma (CM), sentinel node-positive patients still have substantial risk to develop recurrent disease. We aim to investigate prognostic indicators associated with disease recurrence in positive-sentinel lymph node biopsy (SLNB) patients in a Latin-American population.

Methods: Retrospective analysis of CM patients and positive-SLNB (2010-2020). Patients were divided into two groups: Group A (completion lymph node dissection, CLND), Group B (active surveillance, AS). Association of demographics, tumor data and SLN features with recurrence-free (RFS), distant metastases-free (DMFS) and melanoma specific (MSS) survival was analyzed.

Results: Of 205 patients, 45 had a positive SLNB; 27(60%) belonged to Group A and 18(40%) to Group B. With a median follow-up of 36 months, 16 patients (12 in Group A and 4 in Group B) developed recurrent disease and estimated 5-yr RFS at any site was 60% (CI95%, 0.39 - 0.77) (44.5% in CLND group vs. 22% in AS group; P = 0.20). Estimated 5-yr DMFS and MSS: 65% (CI 95%, 0.44 - 0.81) and 73% (CI 95%, 0.59 - 0.89) with no differences between groups (p = 0.41 and 0.37, respectively). Independent predictors of poorer MSS were extranodal extension (ENE) and MaxSize > 2 mm of melanoma deposit in SLN. Factors independently associated with DMFS: Breslow depth > 2 mm, ENE, number (≥ 2) of positive SN and CLND status.

Conclusion: Primary tumor and SN features in melanoma provide important prognostic information that help optimize prognosis and clinical management. AS is now the preferred approach for most positive-SLNB CM patients.