Prognostic Significance of Cyclin E and p27 in Stage I Non-Small Cell Lung Cancer

Jo, Bhong Gyun; Cho, Sung Rae; Chun, Bong Kwon

Abstract

BACKGROUND: Cyclin E plays a pivotal role in the regulation of G1-S transition and could consequently be a deregulated molecule in tumors. The activity of the cdk2-cyclin E complex is increased by degradation of cdk inhibitor p27kip1. Little is known about the expression and prognostic significance of cyclin E and p27 in non-small cell lung cancer(NSCLC). MATERIAL AND METHOD: The expression of cyclin E and p27 in eighty-one cases of resected stage I NSCLC tissues and its relation to major clinico-pathological factors, including histology, differentiation, size of tumor, pleural invasion and survival rate were studied and analyzed. Immunohistochemical analysis with monoclonal antibodies specific for cyclin E and p27 were performed by ABC method. RESULT: Expression rates of cyclin E and p27 in stage I NSCLC tissues were 29.6% and 28.4% respectively. Cyclin E was expressed higher in cases of pleural invasion(p=0.04), and p27 was expressed higher in diameter of tumor less than 3cm(p=0.015). The 5-years survival rate was lower in cases of positive expression of cyclin E than in cases of negative expression of cyclin E(44.4% vs 68.2%, p=0.015), and the 5-years survival rate was 72.2% in positive expression of p27 and 56.2% in negative expression of p27(p=0.09). The 5-years survival rate was higher in negative expression of cyclin E and positive expression of p27 than in cases of positive expression of cyclin E and negative expression of p27 (73.5% vs 36.3%, p=0.0029). In multivariate analysis, expression of cyclin E was an unfavorable prognostic factor(RR=3.578, p=0.006) and p27 was a favorable prognostic factor(RR=0.183, p=0.019) independently.
CONCLUSION
Cyclin E and p27 may play a pivotal role for the biological behavior of stage I NSCLC, so that the expressions of cyclin E and p27 may be new prognostic markers.