Overexpression of gamma glutamyl hydrolase predicts extranodal extension in squamous cell carcinoma of the oral cavity

Abstract

Objective: Extranodal extension (ENE) is an important prognostic factor in oral squamous cell carcinoma (OSCC). However, ENE is only confirmed postoperatively by histologic assessment of the lymph nodes after neck dissection. Accurate identification of ENE preoperatively would help in management of OSCC.

Study design: We determined the expression of molecular markers gamma glutamyl hydrolase (GGH), cyclin-dependent kinase inhibitor-3 (CDKN3), and chromobox homolog-7 (CBX7) using immunohistochemistry in OSCC clinical samples (n = 35). The intensity of staining was scored using a semiquantitative index (HSCORE). The association between clinicopathologic parameters and expression of molecular markers with ENE status was analyzed using chi-square test.

Results: The number of positive nodes and the highest anatomic level of nodal involvement significantly correlated with ENE (P < .05). High GGH expression was significantly associated with ENE (P < .05), with an increased risk for ENE (odds ratio [OR] 9.9, 95% CI 1.08-91.47, P = .04), whereas no significant association was seen for CDKN3 and CBX7 expression with ENE. However, a trend toward significance was observed with a high level of CDKN3 and a low level of CBX7 expression with ENE.

Conclusions: Gamma glutamyl hydrolase offers potential as a predictor for ENE in OSCC, whereas the role of CDKN3 and CBX7 need to be validated in a larger sample.