Colorectal cancer
Colorectal cancer is a group of malignant tumors that develop in the colon or rectum, usually from the lining of the large intestine.
Colorectal adenoma: A benign gland-forming growth in the colon or rectum that can develop into cancer. Many colorectal cancers emerge through a gradual sequence from adenoma to invasive tumor.
Colorectal cancer screening: Testing people without symptoms to detect colorectal cancer or precancerous changes. Screening can find early cancers and remove lesions before they become malignant.
Familial adenomatous polyposis: An inherited disorder in which numerous colorectal adenomas develop, usually because of an APC gene variant. It demonstrates how inherited APC disruption can create a very high lifetime cancer risk.
Anal cancer: Cancer arising in the anal canal or anus, most often a squamous cell carcinoma. It affects the adjacent anorectal region but differs in tissue origin, risk factors, and treatment.
Cancer epidemiology: The study of cancer patterns, causes, and outcomes across populations. It places colorectal cancer incidence and mortality in population-wide context.
APC gene: A tumor-suppressor gene that regulates the Wnt signaling pathway and intestinal cell growth. Loss of APC function often initiates the adenoma-to-carcinoma sequence.
Colonoscopy: An examination of the colon and rectum using a flexible camera passed through the anus. It allows direct inspection, biopsy, and removal of many precancerous polyps.
Hereditary nonpolyposis colorectal cancer: A former name for Lynch syndrome, an inherited cancer-predisposition syndrome involving mismatch-repair genes. Its historical name contrasts with polyposis syndromes, though it is now generally called Lynch syndrome.
Small intestine cancer: A malignant tumor arising in the duodenum, jejunum, or ileum. It develops in a different part of the digestive tract and is far less common.
Cancer survivorship: The health and quality-of-life experience of people living with or beyond cancer. Treatment can leave lasting bowel, sexual, emotional, and physical effects.