Abstract:

Objective To investigate the expression of p53 and Ki67 in breast cancer with negative estrogen receptor (ER), negative progesterone receptor (PR) and negative human epidermal growth factor receptor 2 (HER-2) (triple negative breast cancer), and explore its clinical significance. Methods A total of 233 cases of invasive breast cancer confirmed by pathology were collected, among which 44 (18.88%) were triple negative breast cancer. The expression of p53 and Ki67 in tissues of triple negative breast cancer was detected by immunohistochemical EnVision two-step methods. The tissues of 189 cases of non-triple negative breast cancer were served as controls. The correlation of expression of p53 and Ki67 in triple negative breast cancer with clinicopathological features and their relationship with prognosis were analysed. Results The positive expression rates of p53 and Ki67 in tissues of triple negative breast cancer were 45.5% and 68.2% respectively, which were significantly higher than those in tissues of nontriple negative breast cancer (20.6% and 47.1%) (P<0.05). In triple negative breast cancer, the expression of p53 correlated with tumor size, histological grade, lymph node status and vessel invasion (P<0.05), and the expression of Ki67 correlated with histological grade (P<0.05). The expression of p53 was significantly related to that of Ki67 in all the breast cancer cases (r=0.294, P=0.000), but the expression of p53 was not significantly related to that of Ki67 in triple negative breast cancer cases (r=0.134, P>0.05). In all the breast cancer cases, the overall survival of cases with positive expression of p53 was lower than that of cases with negative expression of p53 (P=0.000), and the overall survival of cases with positive expression of Ki67 was lower than that of cases with negative expression of Ki67 (P=0.000). In triple negative breast cancer cases, there was no significant difference in the overall survival between cases with positive expression of p53 and those with negative expression of p53 (P>0.05) and between cases with positive expression of Ki67 and those with negative expression of Ki67(P>0.05). Conclusion The expression of p53 and Ki67 is up-regulated in tissues of triple negative cancer, while the expression of p53 is not significantly related to that of Ki67. The expression of p53 and Ki67 may be related to the prognosis of breast cancer, while may not indicate the prognosis of triple negative breast cancer.

Key words: breast cancer, triple negative breast cancer, p53, Ki67