Association of cigarette smoking with the expression of nuclear survivin in pathological Stage IA lung adenocarcinomas

Survivin is expressed in the cytoplasm and/or nucleus of various types of malignant tumor cells. Cytoplasmic survivin functions as an apoptosis inhibitor, while nuclear survivin is indispensable for complete mitosis completion. To investigate the effect of cigarette smoking on the survivin expression in lung adenocarcinomas at the early developmental stage, we examined the expression of nuclear and cytoplasmic survivin in pathological Stage IA lung adenocarcinomas resected from 38 non-smokers and 44 smokers (current smokers and ex-smokers) using an immunohistochemical method. Labeling indices of nuclear survivin in tumors of smokers were significantly greater than those of non-smokers. The labeling index of nuclear survivin was above 3 % in only 1 (2.6 %) of the 38 tumors of the non-smokers, while the labeling indices in 19 (43.2 %) of 44 tumors of the smokers were above 3 % with a significantly greater frequency. There was no significant difference in the labeling index of nuclear survivin between current smokers and ex-smokers. There was no significant difference in the labeling index of cytoplasmic survivin between tumors of the non-smokers and the smokers. The present results show that cigarette smoking is associated with the higher nuclear surviving expression in lung adenocarcinomas at the early stage, suggesting that cigarette smoking affects the nuclear survivin expression in lung adenocarcinomas at the early developmental stage.