Smoking cessation leads to changes in survivin expression in oral mucosa

Abstract

Background: Survivin is an inhibitor protein of apoptosis and plays a role in oral carcinogenesis mechanism.

Methods: The aim of this study was to evaluate the effect of smoking in survivin expression of oral mucosa of chronic smokers with and without oral squamous cell carcinoma (OSCC). The study was composed of three groups: Group 1-26 patients smoking more than 20 cigarettes/day/10 years without either history of oral malignant neoplasia or visible clinical signs in the examined site; Group 2-26 patients with OSCC; Group 3-22 patients surgically treated for OSCC for at least 1 month. The immunohistochemistry was performed with 1 smear for each group and analyzed by microscopy regarding extension, intensity of positive cells for survivin, and intracellular location.

Results: The survivin expression was observed in 100% of the cases in Group 1, 88.5% in Group 2, and 100% in Group 3. Concerning to Groups 1 and 3, the survivin expression with cytoplasmic location occurred in 100%, while in Group 2 occurred in 87.5%. The cytoplasmic and nuclear expression was observed only in Group 2, with 7.69%. The results were correlated with clinical-pathological data by Fischer's exact test with significant relation between smoking cessation and intensity (P = .015) for Group 2.

Conclusions: The extension and intensity of survivin expression in the cytological smears were related to the smoking cessation in the group with OSCC. However, the smoking history (packs/years) did not influence the survivin expression.

Keywords: apoptosis; carcinogenesis; squamous cell carcinoma; survivin; tobacco.