The clinical significance of lymphangiogenesis in renal cell carcinoma

Abstract

BackgroundThe formation of lymphatic vessels (lymphangiogenesis) occurs in tumor tissues and is crucial for tumor development and progression in some cancers. Lymphangiogenesis and its clinical effect on renal cell carcinoma have been less thoroughly investigated in comparison with angiogenesis. The aim of this study was to evaluate the role of lymphangiogenesis as a prognostic factor in renal cell carcinoma (RCC).Material/MethodsThe expression of peritumoral/intratumoral lymphatics was studied by immunohistochemical methods in paraffin-embedded nephrectomy specimens from 133 patients with clear cell carcinoma. Patients were divided into 3 groups depending on postoperative follow-up: I) patients without metastases, II) patients with metastases during follow-up, and III) patients with metastases during the operation. Peritumoral lymphatics (PTL) and intratumoral lymphatics (ITL) were immunostained with a D2-40 antibody.ResultsThe mean number of PTL present in each group was I=14.1, II=10.6, III=12.1. The mean number of ITL present in each group was I=0.7, II=2.3, III=2.3. The 3 groups showed statistically significant differences only in the case of ITL. A mean count of ITL ≥1 is significantly associated with an increased risk of regional lymph node involvement and distant metastasis. Patients with expression ITL >0.2 and PTL ≤15.2 had a significantly shorter cancer-specific survival.ConclusionsThe number of ITL showed an association with more aggressive cases of RCC and progression of disease. Therefore, the level of expression ITL, together with stage and histological grading, may provide valuable predictive information about the outcome of treatment.