Objective: To explore the expression and significance of p53, p21(Cip1/WAF1) and Gadd45α protein in breast cancer and their correlations with clinicopathologic features and prognosis in breast cancer.
Methods: The expressions of p53, p21(Cip1/WAF1) and Gadd45α proteins were determined by immunohistochemical staining. The relationship between these three proteins and clinicopathologic features in breast cancer was analyzed by χ(2) test and Spearman's rank correlation analysis. And the survival analyses were performed with the Kaplan-Meier method and Cox regression. The differences between the curves were examined with the two-tailed Log-rank test.
Results: In 133 cases of invasive breast cancer, the positive rates of p53, p21(Cip1/WAF1) and Gadd45α protein were 58.6%, 47.4% and 41.4% respectively. The expressions of p21(Cip1/WAF1) and p53 in cancer were significantly higher than those in the adjacent mammary gland tissue (P < 0.05) while the expression of Gadd45α was lower than that in the control mammary gland tissue (P < 0.05). The positive rate of p21(Cip1/WAF1) was correlated with the histological stage, local recurrence and positive C-erbB-2. And the positive rate of Gadd45α was correlated with the histological stage, lymph node metastasis, metastasis and positive estrogen receptor/progesterone receptor (ER/PR). The positive rate of p53 was correlated with the lymph node metastasis and TNM stage. Spearman's rank correlation analysis showed that p21(Cip1/WAF1) was correlated positively with p53, p53 negatively with Gadd45α while p21(Cip1/WAF1) had no correlation with Gadd45α. With the follow-up data, Kaplan-Meier analysis showed that p21(Cip1/WAF1), Gadd45α, p53, lymph node metastasis, C-erbB-2 positive and TMN stage were associated with prognosis. Furthermore, Cox stepwise hazard analysis shows that p21(Cip1/WAF1), Gadd45α, C-erbB-2 and TMN stage were correlated with prognosis of breast cancer. Also the Kaplan-Meier analysis showed that p53(+)Gadd45α(-) and p53(+)p21(Cip1/WAF1)(+) were correlated with a poor prognosis of breast cancer.
Conclusions: The expressions of p21(Cip1/WAF1), Gadd45α and p53 are associated with the clinicopathologic features and prognosis in breast cancer. Indicating a poor prognosis of breast cancer, p53(+)Gadd45α(-) and p53(+)p21(Cip1/WAF1)(+) may become independent indices for prognostic evaluations.