Abstract

Colorectal cancer (CRC) remains one of the leading causes of cancer-related deaths worldwide, making early diagnosis crucial for improving prognosis and treatment outcomes. This comprehensive guide offers an in-depth exploration of the various diagnostic approaches for colorectal cancer, from initial clinical assessment to advanced molecular testing. The guide begins by examining the risk factors and symptoms commonly associated with CRC, including family history, diet, and lifestyle choices. It further explores the role of screening methods such as fecal occult blood tests (FOBT), colonoscopy, and flexible sigmoidoscopy in detecting early-stage CRC, alongside their respective sensitivities and limitations. The guide also delves into imaging techniques like computed tomography colonography (CTC) and magnetic resonance imaging (MRI), highlighting their application in both screening and staging the disease. In addition, the molecular biomarkers associated with CRC, including KRAS, BRAF, and microsatellite instability (MSI), are discussed for their diagnostic value, particularly in guiding treatment decisions and identifying potential targets for therapy. The guide also includes a section on the evolving role of liquid biopsy as a non-invasive alternative for CRC detection and monitoring. Furthermore, it addresses the importance of a multidisciplinary approach in the diagnosis and management of CRC, involving gastroenterologists, oncologists, radiologists, and pathologists. By providing a holistic overview of diagnostic methodologies, this guide aims to enhance clinical understanding and assist healthcare professionals in making informed decisions for the early detection and personalized treatment of colorectal cancer.