Tenascin expression and angiogenesis in breast cancers

The expression and the distribution of tenascin as well as the extent of bl ood vessel formation (angiogenesis) were investigated in 70 invasive human breast carcinomas. Formalin-fixed, paraffin-embedded specimens were stained with monoclonal an tibody against tenascin-C (DAKO and Biogenex). Anti-CD31 antibody (Biogenex ), an acknowledged marker of stromal angiogenesis, was used to detect endot helial cells. Tenascin immunostaining was positive in the tumours around the persisting n ormal ducts, around tumour-cell nests, in the neostroma, in some tumour cel ls, and it was found in or around vascular channels. Tumour vascularity was assessed by quantitative vascular grading (Chalkley point count) and was related to the localization and intensity of tenascin immunoreactivity. 19 tumours (27.1%) were scored as low, 35 (50%) as medium, and 16 (22.9%) a s having a high vascular grade. The positive correlation between the vascul ar grade and the tenascin immunopositivity in tumour stroma was observed. Our results suggest that tenascin expression may be associated with endothe lial cell activation and may play an important role in tumour angiogenesis.