To explore the expression and diagnostic significance of β-tubulin-Ⅲ proteins, E-cadherin and α-catenin in breast precancerous lesions, including atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinomas (IDC).

The expressions of β-tubulin-Ⅲ, E-cadherin and α-catenin were investigated by immunhistochemical UltraSensitiveTM S-P method of precancerous Lesions including 20 cases of ADH, 60 cases of DCIS, and 90 cases of carcinoma of the breast. 30 cases of normal breast tissues were selected as a control group.

(1)Significant differences of the β-tubulin-Ⅲ proteins expression were found among the four groups of normal breast tissues(20%), ADH(55.0%), DCIS(71.7%)and IDC(84.4%), (χ²=22.298, P<0.05), (P<0.05). (2)The expressions of E-cadherin and α-catenin in observed and controll groups: The expressions of E-cadherin in normal group, ADH, DCIS and IDC were 100%, 75.0%, 68.3% and 41.1%.The expressions of α-catenin in normal group, ADH, DCIS and IDC groups were 100%, 80.0%, 73.3% and 56.7%.There were significant differences of the expressions of E-cadherin and α-catenin between DCIS and IDC(χ²=18.650, 10.970, P<0.05).

Abnormal expression of β-tubulin-Ⅲ may be an early event in the development of breast tumor. The aberration of β-tubulin-Ⅲ may play a key role during oncogenesis and promote breast cellular transformation into malignancy. The abnormal expressions of E-cadherin and α-catenin with the degree of breast disease relates to the development, progression and metastasis of breast carcinoma, which may serve as one of the parameters for diagnosis of breast carcinoma and determine biological behavior and prognosis of breast carcinoma.