Expression of tenascin in invasion border of early breast cancer correlates with higher risk of distant metastasis.

Tenascin (Tn) is an extracellular matrix glycoprotein transiently expressed in epithelial-mesenchymal interaction areas during embryogenesis. Tn is expressed in a limited manner in adult tissues but emerges during wound healing and tumorigenesis. We have studied Tn expression by immunohistochemistry in 137 small node-negative breast cancers treated with breast-conserving surgery and post-operative radiotherapy during 1985-1989. None of the patients had undergone any adjuvant hormonal therapy or chemotherapy. Stromal Tn expression itself could not predict distant metastasis. However, Tn staining in the area of the invasion border seemed to be a strong predictor of distant metastasis, with an estimated 5-year metastasis-free survival (MFS) of 85% in Tn-positive cases compared to 98% in Tn-negative ones. The prognostic impact of Tn in the invasion border on MFS was stronger than that of tumour size and grade. This staining appears to be a useful adjunct for the estimation of breast-cancer metastasis.