ABSTRACT
Breast cancer causes major part of cancer deaths in women and is increasing in incidence. This study assessed the BRCA1 gene expression in breast cancer in women, and compared it with other known prognostic factors for the disease. Thirty patients with positive family history of breast cancer were selected from Beni-Suef and Cairo Universities Hospitals, Egypt for the study. A control group of 10 healthy subjects were also included. Blood samples were withdrawn for routine laboratory and tumor marker [CA15-3] being done by ADVIA Centaur. Archival formalin-fixed paraffin-embedded breast cancer tissues were obtained from the pathology files. Histological types and grading of the tumor were assayed. The immunohistochemistry [IHC] and RNA extraction were also done. Histological grading of the carcinomas was done according to the system of Scarff-Bloom-Richardson. Cells from MCF-7 cell line grown in Roswell medium [Gibco BRL] and known to express BRCA1 were processed into paraffin and used as positive controls for both IHC and real-time reverse transcription-polymerase chain reaction [RT-PCR]. BRCA1 expression was correlated with age, histological type and grade of breast cancer, estrogen and progesterone receptor status, and CA15-3. After statistical analysis of the data, demonstrable BRCA1 mRNA was found in 6 patients samples [20% of the breast cancer tissues] while the other patients showed 80% negative BRCA1 mRNA expression as well as the control group. A positive significant relationship was demonstrated between BRCA1 [mRNA] expression and high histological grade, negative estrogen and progesterone receptor status, and high levels of serum CA15-3. A significant negative correlation was found between BRCA1 mRNA expression and age [r=-0.683; p<0.01] The study demonstrated lack of BRCA 1 gene expression [mRNA] in the majority of breast cancers in Egypt and confirmed the relationship between BRCA1 expression and parameters that determine poor prognosis in breast cancer. Our results suggested that BRCA1 is seen in high-risk women known with positive family history of breast cancer. Strategies for recruitment of Egyptian women in studies of genetic testing for different breast cancer genes have varied levels of success. Our study highlights the need for further studies in this population group