Methylation Status Of ER Alpha Gene In Intraductal Proliferative Lesions Of Breast And Invasive Breast Cancer

[Objective] To detect the 5'CpG island methylation status of estrogen receptor(ER) alpha gene promotor region in usual ductal hyperplasia(UDH), atypical ductal hyperplasia(ADH) and ductal carcinoma in situ(DCIS) of the breast as well as invasive breast carcinoma; and to investigate the possible correlation between the expression of ERα and methylation status of ERα gene.[Methods] Forty-six cases of intraductal proliferative lesions of breast and twelve cases of invasive breast cancer were collected from Qi Lu Hospital of Shandong University from 2002-2005.The samples were fixed in 10% formalin and paraffin embedded. All archival haematoxylin and eosin-stained sections were reviewed to confirm the diagnosis.Immunohistochemistry was used to determine the expression of ERα.The CpG island methylation status of ERα gene were analyzed using methylation-specific polymerase chain reaction(MSP). All the data were analyzed by the chi-square test using SPSS13.0 software for windows.[Results] The CpG island methylation of ERα gene were detected in six of nine UDH samples, seven of nine ADH samples , nineteen of twenty-eight DCIS samples and ten of twelve IBC samples.The positive rates were 66.7%, 77.8%, 67.8% and 83.3% respectively. In the forty-one ERα-positive samples,thirty samples showed methylation of ER-α gene,the methylation rate was 73.2%.In the seventeen ERα-negative samples,twelve samples showed methylation of ERα gene,the methylation rate was 70.6%.[Conclusion] The methylation rate showed no significant difference between UDH, ADH, DCIS and IBC. The methylation rate showed no significant difference between the ERα-positive and ERα-negative group. No correlation had been found between the methylation status and expression of ERα gene. These...