Options for screening for colorectal cancer.

Area of Science:

• Gastroenterology
• Oncology
• Preventive Medicine

Background:

• Colorectal cancer (CRC) screening offers multiple options, with fecal occult blood testing (FOBT) demonstrating significant mortality reduction.
• Endoscopic screening methods like flexible sigmoidoscopy (FS) and colonoscopy are efficient for adenoma detection, a precursor to CRC.

Purpose of the Study:

• To review current and emerging screening methods for colorectal cancer (CRC).
• To evaluate the efficacy and potential of various screening modalities in reducing CRC incidence and mortality.

Main Methods:

• Review of randomized trials on FOBT efficacy.
• Analysis of evidence from case-control and cohort studies on endoscopic screening (FS, colonoscopy).
• Discussion of emerging technologies: DNA-based stool tests and virtual colonoscopy (VC).

Main Results:

• Biennial FOBT reduces CRC mortality by up to 20%; annual screening may offer greater benefit.
• Endoscopic screening, particularly FS, shows promise in reducing distal CRC incidence, though randomized trial data is pending.
• Novel DNA markers in stool offer high specificity for CRC detection, potentially surpassing FOBT.
• Virtual colonoscopy demonstrates high sensitivity for large adenomas and CRC, with ongoing research into its role.

Conclusions:

• FOBT remains a proven method for CRC mortality reduction.
• Endoscopic screening and newer molecular stool tests represent significant advancements in CRC detection and prevention.
• A combination of screening methods may be optimal, with high-quality endoscopy essential for diagnosis and treatment.