Histomorphologic parameters and CXCR4 mRNA and protein expression in sentinel node melanoma metastasis are correlated to clinical outcome

Introduction: Sentinel lymph node (SLN) biopsy is an important independent prognostic factor for invasive cutaneuos melanoma, although its role is strongly debated. in clinical practice SLN leads to complete lymph node dissection of basin draining melanoma site. However only 7-30% of positive sentinel node patients present additional non SLN metastasis. Melanoma cells diffusion through SLN and extranodal spreading depends upon biological features, such as cell chemokine receptors and adhesion molecules. CXCR4 has been proposed in melanoma patients as prognostic marker. Therefore we have analyzed both histopathological parameters and CXCR4 expression in melanoma infiltrate of SLN, in order to evaluate its potential prognostic role. Results: Micrometastases were detected in 23 cases (48.93%); metastases >2 mm in 23 cases (48.93%) and isolated metastatic cells in one case (2.01%). High CXCR4 expression was observed in 21 nodal metastases. node metastases in complete dissection were associated to >10% relative tumor area (RTA) in all lymph nodes (p = 0.006). Extranodal invasion (p = 0.006) and >2 mm centripetal metastasis thickness (p = 0.01), while shorter disease Free Survival (DFS) was significantly associated to high CXCR4 expression (p = 0.02). Materials and methods: Forty-seven positive lymph node metastases were collected and analysed for both histopathological parameters and CXCR4 expression. Conclusion: More than 10% RTA in SLN, extranodal invasion and centripetal metastasis thickness all predict additional lymph node metastases in melanoma site draining basins. Moreover, high CXCR4 expression is correlated to shorter DFS and could be used as a prognostic marker in order to stratify melanoma patients at higher progression risk.