Abstract

Accumulation of mutated p53 rotein in paired primary breast cancers and their metastatic axillary lymph node lesians are evaluated by immunohistochemical method to compare the difference between primary and metastatic foci. Among 75 cases, 19 cases showed increased p53 expression and 1 case showed decreased expression in metastatic foci campared to the primary foci. This nuclear protein was expressed only in the nuclei of the neoplastic cells except for one case which showed positive reaction in the nuclei of the hyperplastic ductal epithelium. This oncoprotein was expressed heterogenously in both primary and metastatic foci and appeared to be distributed more prominently in the invasive margins. We concluded: l) mutated p53 protein expression is heterogenously distributed 2) this mutated p53 protein expression was more frequent and increased in metastatic foci than primary foci 3) p53 gene mutation may be involved in breast cancer progression and evalution of metastatic subclone.

• Keywords: p53, Primary foci, Metastatic foci, Progression, Metastatic subclone