الفهرس 
Primary breast cancer womenOnly 14 pages are availabe for public view
 |  | from | 164 |  |  |
| | | from | 164 | | |
Abstract
According to the Egyptian National Cancer Registry Programme, breast cancer is the leading cancer among Egyptian females (Ibrahim A et al., 2014). At the time of initial diagnosis approximately 5% of patients are found to have advanced or metastatic disease. Although early diagnosis by screening mammography is believed to be responsible for the significant decline in breast cancer mortality, especially for women with premenopausal breast cancer. Thus, alternative approaches to breast cancer detection are clearly needed for improving diagnosis (Cho Y et al., 2010).
Early in the formation and growth of a primary tumour (e.g., breast, colon, lung, or prostate cancer), cells are released into the bloodstream. These circulating tumour cells (CTC) can be enriched and detected via different technologies that take advantage of their physical and biologic properties. CTC analyses are considered a real-time “liquid biopsy” for patients with cancer (Pantel K and Alix-Panabieres C, 2010). The term “liquid biopsy” has also been adopted for the analysis of circulating cell-free tumour DNA (ctDNA) released from apoptotic or necrotic tumour cells. The development of sensitive molecular assays has allowed researchers to screen ctDNA in blood plasma for tumour-specific aberrations; thus, ctDNA and CTC approaches have become competing biomarkers (Diaz L and Bardelli A, 2014).
Therefore, the development of a preoperative blood test that is able to detect early breast tumours would be desirable (Neagu M et al., 2011).In this study, we have investigated the aberrant methylation of two tumour suppressor genes (RARβ2: retinoic acid receptor gene and 3-OST-2: heparan sulphate D-glucosaminyl 3-O-sulphotransferase-2 gene) which are early markers for breast cancer. A total of 178 individuals was enrolled in this study; they were divided into breast-cancer patients (n=93), patients with benign breast tumour (n=55), and healthy individuals (n=30). Using the relative quantitative methylation specific PCR (RQ MSP) technique, the methylations of RARβ2 and 3-OST-2 genes were analysed in the serum samples, and compared with traditional tumour markers and clinicopathological factors. The methylations of RARβ2 and 3-OST-2 – which are tumour suppressor genes – were significantly higher in breast cancer patients than in the benign tumour and healthy individuals (p < 0.0001). Methylated genes were not significantly related to clinicopathological factors apart from the pathological types. Both methylated genes were found in all different tumours regardless the grades and stages. Sensitivities and specificities for the candidate genes were together superior to other tumour markers in the detection of early-stage and low-grade breast cancer.