Nuclear survivin expression is associated with HPV-independent carcinogenesis and is an indicator of poor prognosis in oropharyngeal cancer

Abstract

The relationship between expression of the inhibitor of apoptosis protein survivin and the presence of high-risk human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma (OSCC) remains unclear. This also accounts for its role as a predictor of survival. Therefore, we conducted a multicentre retrospective study on 106 consecutive oropharyngeal cancer patients. Human papillomavirus sequences were detected by nested PCR protocols. Survivin and p16 expression as a surrogate marker for HPV status were analysed by immunohistochemistry. Sequences of high-risk HPV were detected in 29% of cases. Prominent cytoplasmatic expression of survivin was found in 58% of cases and nuclear expression of survivin was found in 19% of the survivin-positive tumours. Nuclear expression of survivin was significantly correlated with HPV-negative tumours (P=0.023) and with a poor disease-free survival rate with an estimated 3-year disease-free survival probability of 35% for tumours with nuclear expression of survivin vs 78% for tumours with non-nuclear expression of survivin (hazard ratio=8.264; 95% confidence interval (95% CI)=2.510–27.210; P<0.001). In multivariate analysis, p16 expression status as well as nuclear expression of survivin were strong independent and opposing prognostic indicators of disease-free survival (hazard ratio=0.068; 95% CI=0.005–0.892; P=0.041 and hazard ratio=15.975; 95% CI=2.377–107.360; P=0.004, respectively). Our data show that nuclear accumulation of survivin correlates with HPV-independent carcinogenesis and is an independent predictor of poor survival in patients with OSCC.