Abstract: The Expression of P53 in Triple Negative Breast Cancer and Its Clinical SignificanceQin ZHANG, Hong LIUCorresponding author: Hong LIU, E- mail: lh713@163.comDepartment of Breast Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, ChinaAbstract Objective: To investigate the expression of P53 in triple negative breast cancer and its relationship with the prognosis.Methods: A total of 580 breast cancer patients treated with surgery in Tianjin Medical University Cancer Institute and Hospital betweenJanuary 2004 and June 2004 were reviewed. The expression of P53 and its prognostic value were evaluated with immunohistochemis-try. Results: The expression rate of P53 was 27.6 % in all of the breast cancer cases ( 161/584 ). Compared with non-triple negativebreast cancer, triple negative breast cancer had a higer rate of P53 expression ( 35.5 % vs 24.8 %, P = 0.01 ). P53 expression was higherin grade Ⅲ cancer than in gradeⅠand Ⅱbreast cancer ( P = 0.001 ). Triple negative breast cancer patients with P53 expression wereprone to have higer rate of relapse and metastasis ( 40 % vs 18.7 %, P = 0.022 ). The 5-year disease free survival rate of P53 positive pa-tients was lower than that of P53 negative patients ( 61.3 % vs 78.6 %, P = 0.022 ). No significant difference was found in P53 expres-sion between triple negative and non-triple negative breast cancer patients with recurrence and metastasis ( P = 0.186 ). P53 expressionwas not related with age, menopause, TNM stge, tumor size, or lymph node metastasis ( P > 0.05 ). Conclusion: P53 expression is anindependent predictive factor for disease free survival of triple negative breast cancer patients.Keywords P53; Triple negative breast cancer; Disease free survival