Patients receiving care through the Veterans Affairs health system who underwent a colonoscopy were 61% less likely to die of colorectal cancer, according to research published in Annals of Internal Medicine.
“Colonoscopy is widely used in the Veterans Affairs health care system for colorectal cancer prevention, but its effect on colorectal cancer mortality is unknown,” Charles J. Kahi, MD, MSc, from Richard L. Roudebush VA Medical Center and Indiana University School of Medicine, and colleagues wrote.
Kahi and colleagues conducted a case-control study using VA-Medicare administrative data to examine the association between colonoscopy and colorectal cancer mortality in veterans and whether it differs by anatomical location of the cancer.
The researchers enrolled 4,964 case patients aged 52 years or older with colorectal cancer who died of the disease by 2010 and 19,856 control patients without prior colorectal cancer. Case patients were matched to four control patients based on age, sex and facility.
Results showed that the odds of undergoing any colonoscopy were significantly lower among case patients (OR = 0.39; 95% CI, 0.35-0.43) than control patients. Participants who underwent colonoscopy had reduced mortality for left-sided cancer (OR = 0.28; 95%, 0.24-0.32) and right-sided cancer (OR = 0.54; 95% CI, 0.47-0.63). A similar reduction in mortality was seen in those who underwent screening colonoscopy (overall OR = 0.3; 95% CI, 0.24-0.38).
Varying intervals between colorectal cancer diagnosis and exposure to colonoscopy did not significantly alter these results.
“Our study showed that colonoscopy was associated with a reduction in colorectal cancer mortality of approximately 60% in the VHA system, although the reduction was less pronounced in the right colon,” Kahi and colleagues concluded. “Reducing variability in colonoscopy effectiveness, particularly against right-sided colorectal cancer, is critical for effective prevention of colorectal cancer.” – by Alaina Tedesco
Kahi reports no relevant financial disclosures. Please see study for all other authors’ relevant financial disclosures.