Adhesion molecules as prognostic factors in nasopharyngeal carcinoma

Objective/Hypothesis: To identify the significance of molecular markers in determining the risk of recurrence and distant metastases in nasopharyngeal carcinoma. Study Design: In this retrospective case study, we evaluated ar chival nasopharyngeal carcinoma specimens for patterns of expression of E-c adherin, beta -catenin, c-erb-B2, and Ki-67, which have been demonstrated t o be important in other tumors. Methods: Fifty-four cases of nasopharyngeal carcinoma were identified, with a maximum follow-up of 13 years. The histo pathological sections were stained using an automated immunohistochemical s tainer (NexES, Ventana Medical Systems, Tucson, AZ) for E-cadherin (Zymed L aboratories [San Francisco, CA] and Transduction Laboratories [Lexington, K Y] clones), beta -catenin (Zymed), c-erb-B2 (Ventana Medical Systems), and Ki-67 (Novocastra, Burlingame, CA). The numbers of positively staining cell s were scored as follows: 0%, 1% to 33%, 34%, to 66%, or greater than 67%. Results: E-cadherin (Zymed) stained positively in only one case. The Transd uction Laboratories clone demonstrated a spectrum of staining in all cases, from complete to disrupted to no identifiable membranous staining. The sta ining was consistently absent at the advancing tumor border, regardless of stage. The loss of beta -catenin expression did not correlate with that of E-eadherin or with clinical outcomes. No staining was identified for c-erb- B2. Ki-67 staining was variable and did not correlate with clinical outcome s. Conclusions: Altered expression or loss of E-cadherin, or both, may resu lt in loss of function, particularly at the infiltrating edge, with resulta nt loss of cell polarity, cell migration, and eventual metastasis. The inte rpretation of E-cadherin staining depends on antibody source. In contrast t o recent studies, beta -catenin expression is not altered and c-erb-B2 expr ession not identified, suggesting that these markers are not important in t he prognosis of nasopharyngeal carcinoma.