(HealthDay News) — Lower endoscopy and fecal occult-blood testing screening correlate with lasting reductions in colorectal cancer mortality, according to two studies published in the New England Journal of Medicine.
Reiko Nishihara, PhD, from the Dana-Farber Cancer Institute and Harvard Medical School in Boston, and colleagues examined the correlation between the use of lower endoscopy (updated biennially from 1998 through 2008) and colorectal cancer incidence and mortality (through June 2010 and 2012, respectively) using data from 88,902 participants in the Nurses’ Health Study and the Health Professionals Follow-up Study who were followed for 22 years.
The researchers documented 1,815 incident colorectal cancers and 474 colorectal cancer deaths. For endoscopy vs. no endoscopy, the hazard ratios for colorectal cancer were 0.57 (95% CI, 0.45-0.72) after polypectomy, 0.60
(95% CI, 0.53-0.68) after negative sigmoidoscopy, and 0.44 (95% CI, 0.38 to 0.52) after negative colonoscopy. After screening colonoscopy and sigmoidoscopy, the multivariate hazard ratios for death from colorectal cancer were 0.59 (95% CI, 0.45-0.76) and 0.32 (95% CI, 0.24 to 0.45), respectively.
In another study, Aasma Shaukat, MD, MPH, from the Minneapolis Veterans Affairs Health Center, and colleagues examined the long-term impact of fecal occult-blood testing using data from 46,551 participants in the Minnesota Colon Cancer Control Study, aged 50 to 80 years, randomized to receive usual care or annual or biennial fecal occult-blood testing screening.
The researchers found that 70.9% of participants died through 30 years of follow-up. Colorectal cancer mortality accounted for 1.8%, 2.2%, and 2.7% of deaths in the annual-screening group, biennial-screening group, and control group, respectively. Colorectal cancer mortality was reduced with screening (relative risk with annual screening, 0.68; with biennial screening, 0.78).
There was no reduction in all-cause mortality.
“The effect of screening with fecal occult-blood testing on colorectal-cancer mortality persists after 30 years but does not influence all-cause mortality,” Shaukat and colleagues wrote.
One author from the Nishihara study disclosed financial ties to the pharmaceutical industry.