Immunohistochemical expression of survivin in oral epithelial dysplasia and different grades of oral squamous cell carcinoma

BACKGROUND: Survivin, a member of the inhibitor of apoptosis proteins family, is not detectable in most differentiated normal adult tissues but is expressed in a wide range of cancer tissues. Survivin expression in cancer has been associated with poor prognosis, cancer progression, and drug resistance, and the expression levels correlate with more aggressive disease and a poor clinical outcome. OBJECTIVE: To evaluate and compare the immunoexpression of survivin in the normal oral epithelium (NOE), oral epithelial dysplasia (OED), and different grades of oral squamous cell carcinoma (OSCC). METHODOLOGY: The patterns of survivin immunoexpression and immunoreactivity were assessed in previously diagnosed, paraffin-embedded sections of 10 tissues of NOE and 15 tissues each of OED and the three grades of OSCC (well-, moderately-, and poorly-differentiated). The pattern of survivin expression was recorded as cytoplasmic, nuclear, or both. Survivin immunoreactivity was assessed semi-quantitatively as the immunoreactive score (IRS). Analysis of variance and Tukey-HSD tests were employed for statistical analysis. RESULTS: No immunoreactivity for survivin was evident in the NOE tissues. In the OED tissues, the immunoexpression pattern of survivin was predominantly nuclear in the basal cells, and in the OSCC tissues, cytoplasmic and nuclear. IRS was highest among the moderately- differentiated OSCC, followed by poorly- and well-differentiated OSCC and OED, with a statistically significant difference in the IRS scores between the normal and the study groups. CONCLUSION: Survivin protein expression may be an important early event in oral carcinogenesis and may predict unfavorable prognosis in OSCC.