CD44 expression is associated with increased survival in node-negative invasive breast carcinoma

Purpose: CD44 is a multifunctional cell surface receptor with many known splice variants, some of which have been reported to play a role in tumor progression. The purpose of this study was to evaluate the prognostic significance of CD44 isoforms in early-stage, lymph node - negative invasive breast carcinoma. Experimental Design: Immunohistochemical staining for CD44 isoforms was done on archival paraffin tissue sections of invasive breast carcinoma from a cohort of lymph node - negative patients who received no adjuvant tamoxifen or chemotherapy and who had a mean clinical follow-up period of 15 years. Immunohistochemical staining was done with antibodies to CD44s, the standard isoform of CD44, and to isoforms containing variant exon 6 (CD44v6); levels of staining were correlated with clinical outcome data. Results: There was a trend towards increased disease-free survival for patients whose tumors had high anti-CD44s positivity (P = 0.05), and a significant association was observed between anti-CD44s positivity and disease-related survival (P = 0.04). Expression of CD44v6 isoforms did not correlate with clinical outcome. Conclusion: CD44 expression, as assessed by immunohistochemical staining with anti-CD44s, may be a favorable prognostic factor in patients with node-negative invasive breast carcinoma.