Different primers for diagnosing circulating cell-free DNA of colorectal cancer

Colorectal cancer (CRC) is currently the fourth most common cancer (1). Five-year survival for stages I and II is 90%, which drops to 14% for stage IV disease (2). Therefore, early detection and treatment are significant for the management of CRC. Many diagnostic methods have been used to detect cancer, such as protein tumor markers, imaging techniques, and tissue biopsy (3). Serum protein biomarkers such as carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) have limited sensitivity and specificity (4,5). Imaging techniques are challenged by small lesions and may be influenced by structures. Tissue biopsy, a gold standard for diagnosing cancer, has disadvantages from invasion and medical complications