Cyclin D1 is one of the G1
cyclins that control cell cycle progression by allowing G1 to S transition. Overexpression of
cyclin D1 has been postulated to play an important role in the development of human
cancers. We have investigated the correlation between
cyclin D1 overexpression and known clinicopathological factors and also its prognostic implication on resected
non-small-cell lung cancer (NSCLC) patients.
Formalin-fixed and
paraffin-embedded tumour tissues resected from 69 NSCLC patients between stages I and IIIa were immunohistochemically examined to detect altered
cyclin D1 expression. Twenty-four cases (34.8%) revealed positive immunoreactivity for
cyclin D1.
Cyclin D1 overexpression is significantly higher in patients with
lymph node metastasis (50.0% vs 14.4%, P = 0.002) and with advanced pathological stages (I, 10%; II, 53.8%; IIIa, 41.7%, P = 0.048; stage I
vs II, IIIa, P = 0.006). Twenty-four patients with
cyclin D1-positive immunoreactivity revealed a significantly shorter overall survival than the patients with negativity (24.0 +/- 3.9 months vs 50.1 +/- 6.4 months, P = 0.0299). Among 33 patients between stages I and II, nine patients with
cyclin D1-positive immunoreactivity had a much shorter overall survival (29.7 +/- 6.1 months vs 74.6 +/- 8.6 months, P = 0.0066). These results suggest that
cyclin D1 overexpression is involved in
tumorigenesis of NSCLCs from early stage and could be a predictive molecular marker for poor prognosis in resectable NSCLC patients, which may help us to choose proper therapeutic modalities after resection of the
tumor.