Abstract: Objective To study the expression and significance of β-catenin, cyclinD1, c-myc in breast carcinoma. Methods Breast tissue specimens from 119 patients with breast carcinomas, 72 patients with breast cystic hyperplasia and 40 normal individuals were studied. Immunohistochemistry was used to detect the expressions of β-catenin, cyclinD1, c-myc, then their relationship with the clinicopathological features of patients with breast carcinoma was analyzed. Results In normal breast tissues, from the 40 control epithelial cells showed equally strong membranous expression of β-catenin protein at the cell-cell boundaries, but the expression of cyclinD1, c-myc was negative. The abnormal rate of β-catenin in breast carcinoma(78.15%) was much higher than that in patients with breast cystic hyperplasia tissues(44.44％), significant correlation was found(P<0.01). The overexpression of cyclinD1, c-myc in breast carcinomas(57.98%, 56.30%) was much higher than that of breast cystic hyperplasia tissues(33.33%, 27.78%), significant correlation was found(P<0.01). The abnormal expression of β-catenin and the overexpression of cyclinD1 was associated with lymph node metastasis(P=0.031, P=0.003). The overexpression of c-myc was associated with size and lymph node metastasis(P=0.041). There was a highly significant association between abnormal expression of β-catenin and overexpression of cyclinD1(P=0.006), but not between abnormal expression of β-catenin and overexpression of c-myc(P=0.775). Conclusion The abnormal expression of β-catenin may play an important role in the carcinogenesis and progression of human breast carcinoma by up-regulating the expression of cyclinD1. β-catenin abnormal expression and the cyclinD1, c-myc overexpression could be considered as useful makers for determining metastasis and prognosis of human breast carcinoma

Key words: breast neoplasma, β-catenin, cyclinD1, c-myc