OBJECTIVE To explore the expression of β-tubulin in premalignant lesions and carcinomas of the breast, and to observe the relationship of its expression with breast cancer pathological features.METHODS The expression of β-tubulin was detected immunohistochemically in 50 specimens of premalignant lesions of the breast (ADH and Peri-PM with ADH), 50 specimens of breast in situ ductal carcinomas (DCIS), and 50 specimens of invasive ductal carcinomas (IDC). Thirty specimens of normal breast tissues served as a control group.RESULTS Immunohistochemical analysis showed that: the differences among the 4 groups (normal breast tissues, breast premalignant lesions, DCIS and IDC, P ＜ 0.05) were significant,and there were also statistically significant differences between any 2 groups (P ＜ 0.05) except for the β-tubulin positive expression comparing DCIS versus IDC (P ＞ 0.05). In addition, β-tubulin was expressed at a higher level in Peri-PM with ADH compared to ADH (P ＜ 0.05). Following the degree of breast epithelial hyperplasia involved, and its development into carcinoma, the β-tubulin positive expression displayed an elevating tendency.We also found a significant positive relationship of β-tubulin expression with lymph node metastasis (P ＜ 0.05), but no significant correlation with histological grading and nuclear grade.CONCLUSION Centrosome defects may be an early event in the development of breast cancer and they can also promote tumor progression. Studies of aberrations of centrosomal proteins provide a new way to explore the mechanism of breast tumorigenesis.