Colorectal Cancer

Colorectal cancer is a type of cancer that starts in the colon or rectum, which are parts of the large intestine in the digestive system. It usually begins as small growths called polyps that can develop into cancer over time. This cancer affects how the body processes waste and absorbs water and nutrients. Common symptoms include changes in bowel habits, blood in the stool, and abdominal discomfort. Early detection is important because it can often be treated successfully if found before it spreads. The disease mainly impacts the digestive tract but can also affect overall health by spreading to other organs. Understanding the signs and getting regular screenings can help catch colorectal cancer early.

Colorectal cancer is a malignant neoplasm arising from the epithelial lining of the colon or rectum, most commonly developing from adenomatous polyps through the adenoma-carcinoma sequence. It involves genetic mutations such as in the APC, KRAS, and TP53 genes, leading to uncontrolled cellular proliferation and tumor formation. The disease is characterized by local invasion and potential metastasis to regional lymph nodes and distant organs, especially the liver and lungs. Clinically, it presents with symptoms like rectal bleeding, altered bowel habits, and iron-deficiency anemia. It is a major cause of cancer morbidity and mortality worldwide, with risk factors including age, family history, inflammatory bowel disease, and lifestyle factors. Diagnosis and staging are critical for guiding treatment and prognosis.