ABSTRACT
Colorectal cancer originates from the regenerating crypts of the mucosa, when gene mutation disrupts the natural process of apoptosis leading to the generation of immortal cell lines, causing heaps of cells that manifest as polyps. Epithelial tumors of the colon and rectum are separated into five groups: premalignant lesions, serrated lesions, hamartomas, carcinomas, and neuroendocrine neoplasms. The staging of colorectal cancer is mostly based on the tumor-node-metastasis (TNM) system designed by the American Joint Committee on Cancer. Clinical symptoms of colorectal cancer include a change in bowel habit, a change in appearance of stools, a feeling of fullness or bloating even after a bowel movement, blood in the stools, persistent abdominal pain or swelling, weakness or fatigue, unexplained weight loss, and a lump in the rectum or anus. Diagnosis of colorectal cancer involves physical examination, imaging, and histologic, immunological, and molecular examination of biopsy and tumor tissues. Surgery remains the mainstay of cure in colorectal cancer.
