Tenascin pattern of expression and established prognostic factors in invasive breast carcinoma

Background and Objectives: Immunohistochemical methods were used to study Tenascin (TN) expression in invasive duct cell carcinoma (IDCC) of the breast and its established prognostic factors. Methods: We studied 115 patients with IDCC. The mean patient age was 62 years; all tumors were graded according to Scarf-Bloom and Richardson. Complete survival information was available for all patients (median follow-up 65 months). Formalin-fixed, paraffin-embedded archival tissue from all 115 IDCC were immunostained with monoclonal mouse AntiHuman Tenascin (DAKO-TN2M636; 1/50 dilution). Positivity was recorded on a scale of 0-4 for percentage of TN staining in the tumor stroma. Results: TN showed thick bands around advancing tumor nests and in poorly differentiated tumors, TN fibers had an interstitial pattern surrounding single tumor cells. TN score was significantly positively correlated with high nuclear grade (P < 0.05), bistologic grade (P < 0.01), mitotic grade (P < 0.005), and combined grade (P < 0.01). TN score did not correlate with long-term survival or with other prognostic factors studied. Conclusions: TN expression was more prominent in tumors with a high combined histologic grade. Our results may suggest that while TN may play a role in limiting tumor spread as proposed by other studies, it may not represent a prognostic factor in invasive breast carcinoma.