Cyclin D1 expression and endocrine therapy are correlated with the prognosis of breast cancer

Aims: The present study is to investigate the relationship between the expression of cyclin D1 and clinicopathological indices of breast cancer. The relationship between cyclin D1 expression and breast cancer prognosis is also studied. Methods: A total of 226 patients with breast invasive ductal carcinoma were included in the study. The expression of cyclin D1 in breast cancer tissues was detected by immunohistochemical staining. Pearson Chi-square test was used to analyze the expression of cyclin D1 at various clinical indicators of breast cancer patients. Kaplan-Meier survival curve analysis was performed to examine how different levels of cyclin D1 expression and the use of endocrine therapy affect the prognosis of breast cancer. Proportional hazard model was employed to carry out COX regression analysis of cyclin D1 and clinicopathological indices. Results: Expression of cyclin D1 was correlated with tumor size, estrogen receptor-alpha and prognosis in breast cancer patients. The number of affected lymph nodes, endocrine therapy, and cyclin D1 expression were factors that affect the prognosis of breast cancer. Patients with higher expression of cyclin D1 had longer tumor-free survival time. Patients with endocrine therapy had prolonged cumulative tumor-free survival time. Endocrine therapy increased the cumulative tumor-free survival time for breast cancer patients with positive cyclin D1 expression. In addition, endocrine therapy prolonged the cumulative tumor-free survival time for breast cancer patients with negative cyclin D1 expression. Conclusions: The present study demonstrates that cyclin D1 expression in breast cancer tissues is correlated with tumor size, estrogen receptor-alpha, recurrence and metastasis. Positive expression of cyclin D1 indicates that endocrine therapy can be effective and have a good prognosis for breast cancer.