What is colorectal cancer?
Colorectal cancer starts in the colon or rectum, often from polyps that become malignant over time. Treatment is guided by stage and may include surgery, chemotherapy, radiation (especially for rectal cancer), and targeted or immunotherapy.
Causes
Most cases arise from acquired genetic changes in bowel lining cells. Diet, inflammation, and inherited syndromes (such as Lynch) can play a role. Not every patient has a known cause.
Risk factors
Age over 50, family history, inflammatory bowel disease, smoking, obesity, low-fibre/high-processed-meat diets, and hereditary syndromes increase risk.
Importance of early diagnosis
Polyps and early cancers found on colonoscopy are far easier to treat. Early stage often means surgery alone or shorter systemic therapy.