Lymphatic microvessels density, VEGF-C, and VEGFR-3 expression in 25 cases of breast invasive lobular carcinoma

Invasive lobular carcinoma (ILC) is the second most common type of invasive breast cancer, having distinct morphologically but also prognostic and therapeutic features. This type of breast cancer shows a higher rate of multiple metastases with a more frequent axillary-lymph-node involvement. Related to these dissemination and metastatic features, we aimed to study the immunohistochemical expression of D2-40, VEGF-C and VEGFR-3 in 25 cases of ILCs stratified according to the histopathological and molecular classification. Regardless of histopathological or molecular subtype, the statistical tests proved that for ILC, the highest D2-40 lymphatic microvessels density (LMVD) was in the peritumoral areas. In classical subtype, the LMVD values were positively correlated with the degree of tumor differentiation and pTNM clinical stages and when these cases were classified based on the molecular criteria the highest recorded values were found in the luminal B subtype. In addition, regardless of the histopathological and molecular subtypes, the D2-40 LMVD varied in the same direction for both VEGF-C and VEGFR-3 categories, with the highest LMVD values recorded in those cases with the highest VEGF-C and VEGFR-3 reactivity, especially in the peritumoral areas. Considering only the molecular luminal A and B subtypes, we have noted that VEGF-C and VEGFR-3 expression was significantly higher in luminal A subtype compared to luminal B. This immunoprofile suggests the existence of a tumor type-specific lymphangiogenesis that may have certain prognostic and therapeutic implications.