Correlations between P53 expression and clinicopathologic factors and the prognosis of Luminal breast cancer

Objective To investigate the correlations between P53 expression and clinicopathologic factors and prognosis of Luminal breast cancer. Methods From January 2009 to December 2012, a total of 283 patients with Luminal breast cancer in the Shanghai General Hospital Affiliated to Shanghai Jiaotong University were included. P53 expressions of them were assayed by immunohistochemistry. Survival analysis was applied using Kaplan-Meier curve and Log-rank test. Single factor analysis and mutiple-factor analysis were applied using Cox proportional hazard regression model. Results The rate of P53 expression was associated with tumor size (χ2=6.285, P=0.043), lymph node metastasis (χ2=15.881, P=0.000), histological grade (χ2=8.132, P=0.043) and Ki-67 (χ2=6.476, P=0.039), but it was not associated with age (χ2=0.955, P=0.328), menopausal status (χ2=3.808, P=0.051), pathological pattern (χ2=0.847, P=0.655), estrogen receptor (χ2=1.867, P=0.172), progesterone receptor (χ2=0.937, P=0.333) and human epidermal growth factor receptor-2 (χ2=0.110, P=0.741). In all the 283 patients, the 5-year relapse-free survival rates for P53-positive group and P53-negative group were 66.7% and 90.7% respectively (χ2=12.609, P=0.000), while the 5-year overall survival rates were 84.4% and 93.4% respectively (χ2=4.153, P=0.042), with significant differences. In Cox mutiple-factor analysis, lymph node metastasis (HR=2.484, 95%CI: 1.393-4.431, χ2=9.497, P=0.002) and P53 over-expression (HR=3.627, 95%CI: 1.061-12.401, χ2=4.220, P=0.040) were independent prognostic factors for the relapse-free survival of patients with Luminal breast cancer, and lymph node metastasis (HR=3.451, 95%CI: 1.891-6.297, χ2=16.290, P=0.000) and higher histological grade (HR=2.806, 95%CI: 1.091-7.219, χ2=4.582, P=0.032) were independent prognostic factors for overall survival. Conclusion P53 over-expression of patients with Luminal breast cancer is associated with prognostic factors such as lymph node metastasis and histological grade, which indicates the worse prognosis. Key words: Genes, p53; Prognosis; Breast neoplasms; Luminal subtype