1. Early diagnosis and early treatment of breast cancer is an effective means to improve the outcome. The most common clinical tests used to diagnose breast cancer are mammography, near-infrared breast scan, needle aspiration cytology, and breast puncture biopsy. Some of these methods are invasive and have limitations for early diagnosis and monitoring of the disease. In contrast, breast cancer tumor markers are easy to detect and can reflect the biological characteristics of the tumor, which is important for the diagnosis, monitoring of efficacy, and prognosis of breast cancer.
2. The CAl53 antigen is a mucus-based glycoprotein anchored to the membrane, including a transmembrane region, an intracellular region, and an extracellular region rich in glycosyl groups. It is present on malignant tumor cells and normal epithelial cells in breast, lung, ovary and pancreas, and is one of the better serum markers for breast cancer. It is a tumor-associated antigen with a high molecular weight ranging from 300 to 450 KD and an antigenic determinant cluster composed of two parts: sugar and peptide. It is located on the surface of the cell, and when the cell is cancerous, the activity of proteases and sialidases on the cell membrane increases, causing the destruction of the cytoskeleton, resulting in the shedding of cell surface antigens and the subsequent increase of CAl53 in the serum.