Background: Although the prognostic value of p53 protein has been extensively studied in breast cancer, there have so far been few immunohistochemical studies of p53 protein using frozen sections in a large series of Japanese women with breast cancer.
Patients and methods: Immunohistochemical staining for p53 protein was performed on frozen sections from 514 Japanese patients with breast cancer with a mean follow-up duration of 31 months.
Results: Two hundred and eight (40.5%) of 514 cases showed nuclear accumulation of p53 protein. There was a significant inverse correlation between p53 protein and estrogen receptor (ER) status. The patients who were positive for p53 protein had a significantly worse outcome in terms of both disease free survival (DFS) (p<0.0001) and overall survival (OS) (p=0.0411) than those negative for p53 protein. The same effect on DFS was seen in subgroups divided either by nodal status or ER status. Multivariate analyses indicated that nodal status, ER and p53 protein were all independent prognostic factors for DFS. The nodal status, ER and tumor size were independent prognostic factors for OS, and p53 protein status was still an independent prognostic factor for DFS in subgroups divided either by nodal status or ER status.
Conclusion: Our findings demonstrated the prognostic value of p53 protein expression for the early recurrence of breast cancer, and the prognostic value of p53 protein expression was independent from that of both the nodal status and ER status in breast cancer.