TENASCIN-C EXPRESSION IN INVASION BORDER OF EARLY BREAST-CANCER - A PREDICTOR OF LOCAL AND DISTANT RECURRENCE

We have recently demonstrated an association between distant metastasi s and the expression of the extracellular matrix glycoprotein tenascin -C (Tn-C) in the invasion border of small axillary node-negative breas t carcinomas. Our purpose was to assess the relationship between the e xpression of Tn-C in the tumour invasion border and several histopatho logical and biological variables and to compare their usefulness in pr edicting local and distant disease recurrences. The original patient g roup consisted of 143 women with axillary node-negative breast cancer (one bilateral) treated with breast-conserving surgery and post-operat ive radiotherapy, and followed for a median of 8 years. Because of the small number of recurrences an additional group of 15 similarly treat ed women with recurrent breast cancer was also studied. The size of th e tumour, its histology, including a possible intraductal component, a nd grade were re-evaluated. The expression of erbB-2, p53, Ki-67 and T n-C was evaluated by immunohistochemistry. Ploidy and S-phase fraction (SPF) were assessed by flow cytometry. The only statistically signifi cant prognostic factor for local recurrence was Tn-C expression in the invasion border. For metastasis Ki-67 positivity, tumour size and Tn- C expression in the invasion border were statistically significant, bu t Ki-67 positivity was the only independent prognostic factor. Tn-C ex pression in the invasion border was associated with a higher prolifera tion rate measured by Ki-67 and SPF, which is consistent with the sugg ested growth-promoting activity of Tn-C. Tn-C may be a useful marker i n selecting patients for adjuvant therapies to reduce the rate of both local and distant cancer recurrences.