Cancerous inhibitor of protein phosphatase 2A (CIP2A) prevents proteolytic degradation of a universal transcription factor, c-Myc. Strong CIP2A expression associates with poor prognosis in early-stage tongue cancer and in other cancers. The aim of this study was to evaluate CIP2A and mucosal inflammation in tongue hyperplasia, in tongue cancer, and in its metastasis. Retrospective tongue and lymph node specimens (n = 105) were stained immunohistochemically with polyclonal antibody anti-CIP2A. CIP2A staining intensity and inflammation were assessed semi-quantitatively with light microscopy. CIP2A was similarly detected in tongue cancer and tongue hyperplasia, whereas local inflammation was stronger in cancer (p = 0.000). CIP2A expression was increased in metastasized cancer compared to non-metastasized (p = 0.019). Markers for poorer survival were tumor size of ≥20 mm, presence of metastasis and nodal CIP2A (p = 0.031, p = 0.000, p = 0.042). Cancer patients aged ≥60 with increased inflammation predicted poor survival (p = 0.037). CIP2A and inflammation might play a role in progression of tongue cancer.

Programmed cell death protein 1 (PD-1) is an immune checkpoint receptor which plays an important role in a patient's immune responses to microbial and cancer antigens. It is expressed in tumor-infiltrating lymphocytes (TILs) with many different malignancies. The aim of the study was to evaluate PD-1 expression and its prognostic value in tongue cancer. The data of tongue squamous cell carcinoma (TSCC) patients (N = 81) treated in Tampere University Hospital between 1999 and 2013 were used. Control data consisted of patients with non-malignant tongue mucous membrane lesions (N = 48). The formalin-fixed paraffin-embedded samples were stained immunohistochemically and scanned via digital microscope. The staining of PD-1 was examined semi-quantitatively. The density and intensity of PD-1 + cells were significantly higher in TSCC than in control samples. The expression of PD-1 correlated with better survival. The expression of PD-1 could be a potential prognostic marker in TSCC. Further research using larger sample size is needed.

P-cadherin (CDH3) is a cell-to-cell adhesion molecule that regulates several cellular homeostatic processes in normal tissues. Lack of CDH3 expression is associated with aggressive behavior in oral squamous cell carcinoma (OSCC). Previous studies have shown that CDH3 is downregulated in high-grade OSCC and its reduced expression is predictive for poorer survival. The aim of this study was to evaluate the expression and prognostic relevance of CDH3 in tongue squamous cell carcinoma (TSCC). A retrospective series of 211 TSCC and 50 lymph node samples were stained immunohistochemically with polyclonal antibody (anti-CDH3). CDH3 expression was assessed semi-quantitatively with light microscopy. Fisher's exact test was used to compare patient and tumor characteristics, and the correlations were tested by Spearman correlation. Survival curves were drawn by the Kaplan-Meier method and analyzed by the logrank test. Univariate and multivariate Cox regression was used to estimate the association between CDH3 expression and survival. CDH3 expression did not affect TSCC patient's disease-specific survival or overall survival. Strong CDH3 expression in the primary tumor predicted poor disease-specific and overall survival in patients with recurrent disease. CDH3 expression in lymph nodes without metastasis was negative in all cases. CDH3 expression was positive in all lymph node metastases with extranodal extension. In contrast to previous report about the prognostic value of CDH3 in OSCC, we were not able to validate the result in TSCC.