Background: P53 plays a key role in cell cycle arrest, apoptosis, DNA repair, and angiogenesis. Although some studies have reported as prognostic factor for poor survival in node-positive breast cancer, controversy about possible prognostic index for node-negative still exists.
Objectives: To look for correlations between the expression of the p53 protein and clinicopathological parameters, and to assess its prognostic value in node-negative invasive ductal breast carcinoma.
Material and Method: Immunohistochemistry using formalin-fixed, paraffin-embedded sections from 71 nodenegative breast carcinomas in Songklanagarind Hospital. Data were analyzed with respect to tumor size, estrogen receptor, and survival.
Results: P53 mutations were found in 12 patients (17%). Expression of p53 was not associated with tumor size, estrogen receptor, and overall survival. Mean follow-up time was 164.4 months (median 163 months).
Conclusion: P53 expression was not a significant prognostic factor for survival in node-negative breast carcinoma.

Keywords: Breast carcinoma, P53, Prognostic factor