Preoperative SCC Antigen, CRP Serum Levels, and Lymph Node Density in Oral Squamous Cell Carcinoma

The prognostic significance of squamous cell carcinoma antigen (SCC-Ag) and C-reactive protein (CRP) levels and lymph node density (LND) has been individually recognized in oral squamous cell carcinoma (OSCC). We investigated the relationship between preoperative serum markers (SCC-Ag and CRP) and postoperative prognostic marker (LND) in this study. We retrospectively analyzed 277 OSCC patients who underwent primary curative resection and neck dissection with/or without adjuvant therapy between March 2008 and November 2013. Serum SCC-Ag and CRP levels were measured preoperatively. Distant metastasis, overall survival (OS), and disease-free survival (DFS) were used to evaluate the prognostic significance of preoperative SCC-Ag and CRP levels in relation to LND. LND (cutoff point ≥0.06) correlated with the pathologic tumor status, pathologic nodal metastasis, degree of differentiation, tumor stage, tumor depth (≥10mm vs <10mm), and perineural invasion (all P values were <0.001). LND was significantly associated with development of distant metastasis, DFS, and OS (all P values were <0.001). Preoperative elevated CRP and SCC-Ag levels were significantly associated with LND (P=0.006), DFS (P<0.001), and OS (P<0.001). LND + patients were further stratified into prognostic groups according to their SCC-Ag and CRP levels (DFS: P=0.010; OS: P=0.003). LND correlated with the incidence of DM, DFS, and OS in patients with OSCC. Concurrent elevated preoperative SCC-Ag and CRP levels are predictors for LND. In addition, SCC-Ag and CRP are markers for classifying high-risk LND + patients with OSCC into subgroups.