Lymphatic vessel density in radical prostatectomy specimens

Formation of new lymphatic channels, or lymphangiogenesis, has been associated with poor prognosis in a number of human cancers. Its prognostic significance in prostate cancer is uncertain. We analyzed 122 radical prostatectomy specimens. Immunohistochemistry for lymphatic vessels was performed using a mouse monoclonal antibody reactive with an O-linked sialoglycoprotein found on lymphatic endothelium (clone D2-40, Signet Laboratories, Dedham, Mass). The mean lymphatic vessel densities (LVDs) of the 3 prostate compartments were compared. Lymphatic vessel densities were correlated with other clinical and pathologic characteristics. Mean values for intratumoral, peritumoral, and normal prostate LVD were 3.0, 5.2, and 4.8 lymphatic vessels per 200× field, respectively. The intratumoral LVD was significantly lower than the peritumoral or normal LVD (P < .001), and the LVD of the latter 2 compartments was not significantly different (P = .29). The prostate LVD did not correlate with other clinical and pathologic parameters. In conclusion, LVD is reduced in the intratumoral compartment compared with the peritumoral and normal prostate compartments, whereas the latter 2 have similar LVD. In contrast to other malignancies, quantitation of lymphangiogenesis in prostatic adenocarcinoma does not appear to offer useful prognostic information.