Expression and prognostic significance of cyclin B1 and cyclin A in non-small cell lung cancer

Aims: Aberrant expression of cell cycle regulators has been implicated in the pathogenesis of many neoplasms, including non-small cell lung cancer (NSCLC). The aim was to examine the expression and prognostic value of cyclin B1 and cyclin A, key regulators of the G(2)/M checkpoint of the cell cycle, in NSCLC and bronchial precursor lesions. Methods and results: Immunohistochemical expression of cyclin B1 and A was examined in 90 cases of stage I-II primary NSCLC and bronchial precursor lesions using tissue microarrays. Increased cyclin B1 and A expression was found in 40.9 and 58.9% of NSCLC cases, respectively, and was significantly higher in primary NSCLC, lymph node metastases and some bronchial precursor lesions compared with normal bronchial epithelium. Increased expression of cyclin A and cyclin B1 correlated with tumour type, poorly differentiated tumours and male gender. A significant association was found between increased cyclin B1 expression and reduced survival using Kaplan-Meier survival analysis. On multivariate analysis, cyclin B1 was not an independent prognostic factor (P = 0.067). Cyclin A expression was not associated with survival. Conclusions: Cyclin B1 and cyclin A are aberrantly expressed in NSCLC and some precursor lesions. Cyclin B1, but not cyclin A, shows some promise as a potential prognostic marker in NSCLC.