Cyclin D3 expression, cell proliferation and pathological stage of human primary colorectal cancer

Cyclin D3 promotes cell cycle progression but its expression and prognostic significance in human colorectal cancer is unknown. This study assayed cyc lin D3 expression against cell cycle phase fraction and Duke's stage in 35 fresh human primary colorectal cancers. DNA content, cell cycle phase fract ion and cyclin D3 expression were assessed by flow cytometry in disaggregat ed tumors. Cyclin D3 expression and S-phase fraction were independently rel ated to Duke's stage. In Duke's stage C tumors, a higher proportion of cell s expressed cyclin D3 (14.4 vs. 8.8%, mean; p < 0.05 by Mann-Whitney U test ) and were in DNA synthesis (S) phase (21.1 vs, 9.7%, mean; p < 0.05 by Man n-Whitney U test). Neoplastic deregulation of cyclin D3 expression may prov ide a selective growth advantage which is related to stage in human colorec tal cancer.