Tenascin-C expression in prostatic intraepithelial neoplasia (PIN): a marker of progression?

Background: Tenascin (tenascin-C) has been suggested to be associated with active epithelial-stromal interactions. We evaluated tenascin expression in tissue remodelling processes presumably associated with PIN and prostate carcinoma (PCa).
Materials and Methods: Tenascin immunoreactivity was evaluated in 38 PIN lesions (low-grade = 5, high-grade = 33) from 27 paraffin-embedded PCa specimens, and compared with expression in pre-existent (normal) prostate, benign prostatic hyperplasia (BPH), and PCa.
Results: Periepithelial stromal tenascin expression was low in low-grade PIN, and similar to normal glands and BPH, whereas expression in high-grade PIN was high and partly overlapped that of well-/moderately differentiated PCa. High-grade PCa usually expressed little, if any tenascin.
Conclusions: The variable periglandular tenascin expression in high-grade PIN may reflect the biologic behaviour of this lesion, and may be indicative of variable levels of tissue remodelling. In well/moderately differentiated PCa tenascin expression levels may be an indicator of tumour progression.