Breast Cancer Patients: Detection of Circulating Cancer Cell-Related mRNA Markers with Membrane Array Method

The diagnosis and the therapy of early-stage tumors have the potential to decrease morbidity and mortality of patients with malignancy. Although promising advances in imaging technology and other diagnostic modalities have been achieved recently, early diagnosis of patients with malignancy remains a challenge for physicians. It was reported by Weidner (1993) that active angiogenesis may occur in cancer tissues growing to 2 mm in diameter. Evidence is accumulating that primary cancers begin shedding neoplastic cells into the circulation at an early stage (Smirnov et al., 2005); ∼ 10⁶ cells are shed daily per gram of tumor (Chang et al., 2000). Thus, circulating tumor cells (CTCs) is a potential source for the noninvasive and early diagnosis for cancer patients. O’Sullivan et al. (1997) indicated that preoperative detection of micrometastases may reflect either transient shedding of tumor cells, metastatic potential, or residual disease, but postoperative micrometastases are likely to indicate minimal residual disease. Such neoplastic cells may be present in the bloodstream in very low numbers and would hardly be detected by conventional methods. Consequently, a sensitive and powerful method for detection of CTCs is essential not only to increase the accuracy, but also to aid in the development of a novel non-invasive diagnostic strategy.