Lymph node status and survival in cutaneous malignant melanoma--sentinel lymph node biopsy impact

The survival benefit of sentinel lymph node biopsy (SLB) with lymphadenectomy for microscopic melanoma metastases to regional lymph nodes (SLND) is uncertain. The aim of the study was to analyse the factors influencing clinical outcome (overall survival (OS) and disease free survival (DFS)) of patients undergone lymph node dissection (LND) as result of positive sentinel lymph node disease (SLND) or as consequence of clinically detected metastases (CLND).

This was a single-institution retrospective analysis of survival data of 350 consecutive, prospectively collected, melanoma patients who underwent radical LND in 1995-2001. One hundred and forty-five patients underwent SLND and 205 underwent CLND.

The median OS and DFS times of the entire group of melanoma patients, computed from the date of primary lesion excision, were 46.3 months and 26.5 months (5-year OS ratio 41.8% and 5-year DFS ratio 31.5%). The factors which correlated with poor OS by multivariate analysis were: primary tumour Breslow thickness >4 mm (p=0.001), extracapsular extension of lymph node metastases (p=0.004), male sex (p=0.001) and metastases to more than one regional lymph node (p=0.04). The negative factors for DFS were: nodal extracapsular invasion (p=0.00002) and primary tumour Breslow thickness >4 mm (p=0.004). There were no significant differences in OS and DFS between SLND and CLND groups, when calculated from the date of primary tumour excision. However, if OS and DFS were estimated from the date of LND, the SLND group demonstrated significantly better survival in comparison with CLND.

The study demonstrates no survival benefit from SLB with subsequent radical regional LND in malignant melanoma patients with lymph node metastases.