Risk of Incident Colorectal Cancer and Death After Colonoscopy: A Population-based Study in Utah

Area of Science:

• Gastroenterology
• Oncology
• Preventive Medicine

Background:

• Colonoscopy is a recommended colorectal cancer (CRC) screening method in the US.
• Limited evidence exists on the effectiveness of colonoscopy in reducing CRC incidence and mortality.
• This study investigated the association between colonoscopy and CRC outcomes in Utah.

Purpose of the Study:

• To determine if colonoscopy exposure decreases the odds of incident colorectal cancer (CRC).
• To assess if colonoscopy exposure decreases the odds of death from CRC.
• To evaluate the effectiveness of colonoscopy screening in a real-world population.

Main Methods:

• A case-control study was conducted using Utah residents aged 54-90.
• Cases were individuals diagnosed with CRC between 2000-2010; controls were age- and sex-matched individuals without CRC.
• Colonoscopy receipt was determined from administrative claims data, and exposure was analyzed using conditional logistic regression.

Main Results:

• Colonoscopy exposure was associated with reduced odds of CRC diagnosis (OR 0.41) and death from CRC (OR 0.33).
• Significant risk reductions were observed for both proximal colon cancer (OR 0.58) and distal colon/rectal cancer (OR 0.29).
• These findings were consistent across different sexes, age groups, and cancer stages.

Conclusions:

• Colonoscopy is linked to a substantial reduction in new-onset CRC and CRC-related mortality in the Utah population.
• The risk reduction for CRC was most pronounced in the distal colon and rectum.
• A more modest, yet significant, reduction in risk was observed for proximal colon cancer.