[Prognostic significance of cyclin-dependent kinase inhibitor p27kip1 expression in human breast cancer].

OBJECTIVE

To study the expression of p27kip1 in breast cancer in relation to biological behavior and prognosis.

METHODS

p27kip1 expression at protein level was determined by immunohistochemistry technique in 181 patients with breast cancer. In addition, p27WAF1/CIP1, p53 and mdm2 were examined in 106 cases of this series. Data about apoptotic index, bcl-2 and bax protein expression were available in the other 91 patients.

RESULTS

Of the 181 patients, p27kip1 expression was low in 121 (66.9%) and high in 60 (33.1%), respectively. p27kip1 expression level was correlated with histological grade, tumor size, axillary lymph node status, post-operative recurrence, invasion and metastasis. It was also correlated with bcl-2, bax, p53, p21WAF1/CIP1, and mdm2 expression levels. Univariate analysis demonstrated better disease-free survival in patients with higher p27kip1 expression than in those with lower expression. However, by Cox multivariate analysis, p27kip1 expression level was not found to be of independent prognostic significance.

CONCLUSION

As an inhibitor of cyclin-dependent kinase, p27kip1 favors prognosis of human breast cancer not only by arresting cell cycle in G1 phase but also inducing cancer cell apoptosis.