Sentinel lymph node biopsy: Is it possible to reduce false negative rates by excluding patients with nodular melanoma?

Objective: The aim of this study was to review the outcome of sentinel lymph node biopsy (SLNB) in patients with melanoma and to delineate whether patients with nodular melanoma are more likely to develop nodal recurrence despite negative SLNB. Methods: Consecutive patients with cutaneous melanoma undergoing SLNB were identified from a departmental database between 1997 and 2005. Factors including demographic data, site, histological subtype, depth and outcome were examined. Results: Of 131 patients, 103 were node negative and eligible for study. The median age was 53 (16-82) years with 46 patients being male (45%) and 57 female (55%). Primary melanoma sites included lower limb (49; 48%), upper limb (29; 28%), head (12; 11%), trunk (7; 7%) and back (6; 6%). The median Breslow thickness was 2mm. Superficial spreading accounted for 43% of melanoma with nodular accounting for 42%. Median follow-up was 40 (3.90) months. Of 20 relapses, seven recurred in the same nodal basin, three were satellite recurrences, one recurred with both satellite and nodal lesions simultaneously, and nine experienced haematogenous spread. Of the eight patients who developed recurrence in the same nodal basin, four were of nodular histological subtype (p=NS). All of the three patients with satellite lesions had nodular melanoma histologically (p=0.02). When nodal and satellite recurrences were combined, eight of 11 were histologically nodular (p=0.01). Conclusions: This study indicates that lymphatic recurrence occurs more often in SLNB negative patients with nodular melanoma. Further evaluation of the inclusion criteria for sentinel node biopsy is warranted.