Positive expression of cyclin D1 is an indicator for the evaluation of the prognosis of breast cancer

Aims: The present study is to detect the expression of cyclin D1 in different clinical molecular subtypes in breast cancer, and to analyze its relationship to the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (Her-2), tumor size, clinical stages, histological grades, age of menarche, and prognosis. Methods: In the present study, we retrospectively reviewed the clinical information of 226 patients with breast cancer who were hospitalized at The First Affiliated Hospital of Xinjiang Medical University between January 2000 and December 2012. Immunohistochemical method was used to detect the expression of cyclin D1 in breast cancer tissues. Pearson's Chi-square test was performed to compare the expression of cyclin D1 under different clinical indicators, and under different immune indexes and subtypes. Spearman rank correlation method was used to analyze the correlation between cyclin D1 expression and ER, PR, Her-2, tumor size, clinical stages, histological grades and age of menarche. Kaplan-Meier was employed to calculate the survival time of tumor-free survival time. Log-rank method was used to analyze the survival curves. Results: The expression of cyclin D1 was not significantly correlated to tumor size, clinical stages, histological grades, age of menarche, or PR, but was correlated to ER. Higher cyclin D1 positive rate corresponded to higher ER positive rate. The expression of cyclin D1 was negatively correlated to Her-2 expression (P < 0.05). Higher cyclin D1 positive rate corresponded to lower Her-2 positive rate. In cyclin D1 positive group, the percentage of Luminal A type was the highest. In cyclin D1 negative group, the percentage of Luminal B type was the highest. Higher cyclin D1 positive rate led to longer tumor-free survival time. Conclusions: The expression of cyclinD1 is significantly correlated to ER and Her-2. Positive expression of cyclin D1 suggests good prognosis, and can be used as an indicator for the evaluation of the prognosis of breast cancer.