High CIP2A immunoreactivity is an independent prognostic indicator in early-stage tongue cancer

BACKGROUND: No reliable prognostic markers exist for squamous cell carcinoma of the tongue, and its prognosis can even in early stages be unpredictable and survival poor despite treatment. A potential marker is oncoprotein cancerous inhibitor of PP2A (CIP2A), which acts as a prognostic marker in gastric and non-small cell lung cancers. METHODS: We collected specimens of 73 stage T1N0M0 and T2N0M0 oral squamous cell carcinomas of the tongue, as well as samples from normal oral mucosa, dysplastic lesions, and invasive carcinomas (n=39). All samples were stained for CIP2A by immunohistochemistry. Survival curves were constructed according to the Kaplan–Meier method. The Cox proportional hazard model served for univariate and multivariate survival analysis. RESULTS: High CIP2A immunoreactivity predicted poor survival in tongue cancer patients (P=0.027, logrank test). In multivariate survival analysis, CIP2A was an independent prognostic factor (HR 2.02, 95% confidence interval 1.07–3.82, P=0.030). Cytoplasmic CIP2A expression was higher in severe dysplasia than in mild dysplasia. CONCLUSION: Our results suggest that high CIP2A expression characterises aggressive disease. Acting as a prognostic marker it might be of help when choosing patients for adjuvant treatment in tongue cancer patients.