Further Evidence that Screening Reduces Death from Colorectal Cancer

According to the New England Journal of Medicine, screening for colorectal cancer provides long-term protection against death caused by the disease.

A colonoscopy remains the gold standard by which the effectiveness of other screening methods for colorectal cancer are measured. Other screening methods include a sigmoidoscopy, in which only the lower portion of the large intestine is scoped, fecal occult blood testing (FOBT), virtual colonoscopy and a barium enema.

Although short-term effects of colorectal screening have been well establish, the long-term effects of colorectal screening methods have not been well documented, particularly for methods other than a colonoscopy.

To address this lack of data, researchers conducted two clinical studies to evaluate follow-up data from various screening methods for colorectal cancer. The first study included 30 years of follow-up for screening including FOBT either annually or biannually. The study included over 46,500 participants aged 50 to 80 years who were participants in the Minnesota Colon Cancer Control Study.

The second study included nearly 89,000 individuals who were participants in the Nurses’ Health Study and the Health Professionals Follow-up Study. These patients were treated with either a sigmoidoscopy or a colonoscopy and followed over 22 years.

All methods of screening reduced the risk of death from colon cancer.
At 22 years of follow-up, screening with colonoscopy reduced the risk of death from colon cancer by 68% and screening with sigmoidoscopy reduced this risk by 41%.
Screening with FOBT reduced the risk of death from colon cancer by 32% if performed annually, and 22% if performed biannually.
The researchers concluded that screening, either with FOBT, sigmoidoscopy or colonoscopy significantly reduced the risk of death from colorectal cancer. Colonoscopy reduced this risk by nearly 70%, indicating that screening measures really can save lives.

Individuals 50 years or older, or those with a family history of colorectal cancer, should speak with their physician regarding their risks and benefits of screening colonoscopy.

References: Shaukat A, Mongin S, Geisser M, et al. Long-term mortality after screening for colorectal cancer. New England Journal of Medicine. 2013; 369:1095-1105.

Nishihara R, Wu K, Lochhead P, et al. Long-term colorectal-cancer incidence and mortality after lower endoscopy. New England Journal of Medicine. 2013; 369:1095-1105.