Which rationale best explains how colonoscopy with polypectomy reduces colorectal cancer incidence and mortality?

• A. Colonoscopy allows direct visualization and removal of precancerous polyps before malignant transformation, interrupting the adenoma–carcinoma sequence and thereby lowering both incidence and mortality.
• B. Colonoscopy works mainly by improving patient awareness and diet through counseling during the procedure; the mechanical removal of polyps is incidental and not necessary for cancer prevention.
• C. The primary benefit of colonoscopy is to administer localized chemotherapy to the colon mucosa at the time of screening, which prevents any mutated cells from proliferating; removal of polyps is rarely done because it increases cancer spread risk.
• D. Colonoscopy reduces cancer by sterilizing the colonic lumen with antiseptic irrigation during the procedure, which removes carcinogenic bacteria and permanently alters risk for life-long protection.

Answer: (A)