Expression of ER, Ki-67 and cylinD1 in the pre-cancerous breast of Chinese patients

To investigate the expression and association of ER, Ki-67 and cyclinD1 in usual ductal hyperplasia(UDH), atypical ductal hyperplasia (ADH) and ductal carcinoma in situ(DCIS) in the breast. The study included 56 cases of pre-cancerous lesions which were surgically excised at Qi Lu Hospital of Shangdong University. Immunohistochemistry was used to determine the expression of ER, Ki-67 and cyclinD1 and double-labelling immunofluorescence technique was used to observe the coexpression of ER and Ki-67. The expression and distribution of ER-positive cells were significantly different in UDH, ADH and DCIS. The ER-positive cells were much more in UDH than in normal TDLUs (terminal duct lobular units). The distribution of ER-positive cells interspersed amid ER-negative cells within UDH. However , the ER positive cells showed marked increases in ADH and low grade nuclear DCIS (P < 0.05), distributing in almost all constituent cells. The expression of ki-67 and cyclinD1 were significantly different between UDH and DCIS (P < 0.05) , and a positive correlation was found between expression of Ki-67 and morphological classification of pre-cancerous lesions (r = 0.3522, P < 0.05) as well as cyclinD1 (r = 0.3901, P < 0.05). Double-labelling immunofluorescence showed that there was no coexpression of ER and Ki-67 in normal breast tissue. The coexpression of the two markers was found in ADH and increased in DCIS. Overexpression of ER, Ki-67 and cyclinD1 significantly accompanies the transition of normal cells and UDH to ADH and DCIS. The coexpression of ER and ki-67 may present the early change in carcinogenesis of breast cancer.