Sentinel Lymph Node Biopsy in Cutaneous Melanoma: A Case-Control Study

Abstract

Sentinel lymph node biopsy (SLNB) is the most precise method for staging invasive cutaneous melanoma, but its therapeutic effect has been difficult to assess, and SLNB is not routinely used in all melanoma treatment centers. This case-control study of 305 prospective SLNB patients compared them with 616 retrospective patients who had not undergone invasive nodal staging at diagnosis. Thin melanomas were included in both study groups. A total of 50 SLNB patients were sentinel positive (16.4%) and 255 were sentinel negative (83.6%). A total of 49 of the 50 sentinel-positive patients underwent completion lymph node dissection, and 9 of them (18%) had additional metastases in the nonsentinel nodes. The false-negative rate was 1.6% (five same-basin nodal recurrences during follow-up). There was a significant difference in melanoma-related overall survival (OS) between sentinel-positive and sentinel-negative patients (P < .001). The tumor burden of the sentinel nodes was a significant prognostic factor for melanoma-related OS (P < .001). There was no significant difference in melanoma-related OS or disease-free survival between the study groups, but the nodal disease-free survival was significantly longer among the SLNB patients (P = .004). SLNB is recommended for routine use in the treatment of cutaneous melanoma because the sentinel node status carries unique prognostic information on the survival of melanoma patient. Improved regional disease control is an obvious therapeutic advantage of SLNB and immediate completion lymph node dissection.