DF3 epitope expression on MUC1 mucin is associated with tumor aggressiveness, subsequent lymph node metastasis, and poor prognosis in patients with oral squamous cell carcinoma

Background: DF3/MUC1 mucin is expressed in various cancer tissues, and many in vitro studies have suggested that it may play a role in the aggressive behavior of malignant tumors. However, to the best of the authors' knowledge, the relation between DF3/MUC1 expression and outcome has not yet been investigated in patients with oral squamous cell carcinoma (OSCC). The objective of the current study was to evaluate the prognostic significance of DF3/MUC1 expression in patients with OSCC. Methods: The expression profile of DF3/MUC1 in OSCC tissues from 206 patients was examined using immunohistochemistry. Its prognostic significance in OSCC was statistically analyzed on the basis of detailed clinicopathologic factors. Results: DF3/MUC1 expression was found to be significantly correlated with tumor aggressiveness, such as pathologic lymph node metastasis (P =.002), advanced tumor stage (P =.02), diffuse invasion of cancer cells (P =.03), and vascular invasion (P =.01). Respectively, the overall survival (OS)and disease-free survival (DFS) rates were significantly worse for patients with DF3/MUC1 expression compared with those without DF3/MUC1 expression (P =.001 and P =.0003, respectively). Multivariate analysis demonstrated that DF3/MUC1 expression was an independent prognostic factor for both OS and DFS (P =.04 for both). In addition, DF3/MUC1 expression was found to be an independent risk factor for subsequent regional lymph node metastasis (P =.03). Conclusions: Aberrant expression of DF3/MUC1 is an independent prognostic factor indicating poor prognosis in patients with OSCC. DF3/MUC1 expression is a risk factor for subsequent lymph node metastasis in patients with OSCC and therefore may represent an indication for elective neck dissection. Patients with OSCC demonstrating positive expression of DF3/MUC1 should be followed carefully. Cancer 2012.