Background: The contribution of p53 and HER-2/neu to the management of node-negative breast cancer (NNBC) could be improved by combining their results.
Material and methods: We studied paraffin-embedded primary tumors for p53 (BP-53-12-1) (n=57) and HER2/neu (pAB1) (n=63) from NNBC patients. The results were grouped in a negative (p53(-)/neu(-)) versus a positive group (one or both overexpressed). The association between both groups (negative and positive) and clinicopathologic parameters, S-phase fraction and DNA ploidy, and patients' outcome, was analyzed.
Results: In 28% of the tumors p53 was overexpressed, and HER2/neu in 11%. Sixty-five percent (37 out of 57) were p53(-)/neu(-), and 35% overexpressed one (31.5%) or both (3.5%) oncoproteins. Significant correlations were found between p53(-)/neu(-) tumors and age greater than 50 (p=0.003), S-phase fraction lower than 7 (p=0.03), and positive estrogen receptor contents (p=0.049). Actuarial 5-year disease-free and overall survival for p53(-)/neu(-) tumors were 88% and 97%, respectively, versus 50% and 66%, for tumors overexpressing one or both oncoproteins (p=0.004).