Study of the Relationships between Cyclin D1 and Known Prognostic Factors in Breast Cancer

ABSTRACT

PURPOSE: Cyclin D1, which is known as a cell regulatory protein in G1-S phase, is overexpressed in 30-90% of breast cancers. Published data on the relationships between cyclin D1 and the established clinicopathologic factors of breast cancer have been controversial, so we investigated the clinical significance of cyclin D1 and its associations with established clinicopathologic factors in 103 primary breast-cancer patients. METHODS: Cyclin D1 overexpression was measured by using immunohistochemical assays, and the results were compared with clinicopathologic factors. RESULTS: Expression of cyclin D1 was detected in 60.2% (62/103) and cyclin D1 was significantly correlated with the estrogen receptor, the progesterone receptor, lymph-node metastasis, histologic grade, and nuclear grade. But there were no associations between cyclin D1 and tumor size, tumor stage, vascular invasion of tumor, DNA ploidy and S phase. CONCLUSION: We found that breast cancer with cyclin D1 overexpression was associated with predictive factors such as the estrogen receptor and the progesterone receptor. Thus, we suggest that aggressive treatment is needed in breast cancer with cyclin D1 overexpression. For cyclin D1 to become a more informative clinical prognostic factor, more prospective studies with large sample sizes are needed.