Abstract: Objective To investigate the expression of P53 and its correlation with clinicopathological characteristics in invasive breast cancer. Methods A total of 709 cases of invasive breast cancer were collected in the Nantong Cancer Hospital from January 2015 to December 2017. The expressions of P53 in 709 cases were detected with immunohistochemistry. The expression of P53 and its correlation with molecular classifications, histologic grades and expressions of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2) and Ki-67 were investigated and analyzed. Results The high positive rate of P53 was 26.8% (190/709), low positive rate of P53 was 73.2% (519/709). The high positive rate of P53 in luminal subtype A, luminal subtype B with negative HER-2, luminal subtype B with positive HER-2, HER-2 over-expressing subtype and triple negative subtype were 6.1% (12/197), 18.0% (34/189), 39.1% (25/64), 50.0% (58/116) and 42.7% (61/143), respectively. There were significant differences in expressions of P53 between five luminal subtypes (P＜0.05). The expression level of P53 was higher in breast cancer with medullary histological features than that in other histologic subtypes (P＜0.05). The expression of P53 increased with the rise of histologic grades (P＜0.05). The expression level of P53 was higher in breast cancer with ER negative, PR negative, HER-2 positive and high Ki-67 expression groups (all P＜0.05). Conclusion P53 plays a significant role in the development and progression of invasive breast cancer. The expression of P53 can be used to guide the individualized therapy and as a reference index to clinical outcome prediction in invasive breast cancer.

Key words:  breast neoplasms, tumor suppressor protein p53, receptors, estrogen, Ki-67 antigen, progesterone receptors, human epidermal growth factor receptor 2