Can lymphatic vascular density be used in determining metastatic spreading potential of tumor in invasive ductal carcinomas?

Regional lymph node status is the primary parameter determining treatment strategies and prognoses in breast cancer. Lymphatic vessels in primary tumor tissue play a significant role in lymphatic metastasis. The aim of this study was to investigate the correlation of intra- and peritumoral lymphatic microvessel densities (LVD) with prognostic parameters in breast cancer, including lymphatic invasion (LI). Lymphangiogenesis was investigated using D2-40 monoclonal antibody in 69 invasive ductal carcinoma cases who underwent mastectomy and axillary lymph node dissection. Positively stained microvessels were counted at 400× in dense lymphatic vascular foci (hotspots). Tumor LI was established when at least one neoplastic cell cluster was clearly visible inside a D2-40-positive lymph vessel. Relationships were sought between clinicopathological parameters and mean LVD and LI in primary tumor tissue. Peritumoral LVD was markedly higher than intratumoral LVD (p < 0.001). No significant relationship was found between intratumoral LVD and clinicopathological parameters (p > 0.05). However, significant relationships were detected between peritumoral LVD and LVI [H&E] (p = 0.04), number of lymphatic invasion [n/mm2, D2-40] (p = 0.001), tumor size (p = 0.01), lymph node status (p = 0.03), and tumor stage (p = 0.04). The immunohistochemical determination of LI and LVD can contribute to the prediction of a tumor's biological behavior in invasive ductal carcinomas. Peritumoral LVD in primary tumor tissue is closely related to parameters influencing the prognosis of a tumor.