NEJM: Colon cancer screening reduces mortality rates

A study published October 7 in the New England Journal of Medicine has found that colon cancer screening reduces mortality rates at 10-year follow-up.

Although the study was conducted using colonoscopy, its results would appear to support the efficacy of screening for colon cancer with CT colonography (CTC) as well.

Colonoscopy is the gold standard for colon cancer screening, but its effect on the disease's risk and mortality rates could be further clarified, wrote a team led by Dr. Michael Bretthauer, PhD, of the University of Oslo in Norway. Bretthauer and colleagues conducted a study that included data from more than 84,000 individuals taken from population registries in Poland, Norway, Sweden, and the Netherlands for the time period of 2009 to 2014.

Study participants were randomized into groups to receive an invitation to screen with colonoscopy or to not receive an invitation to screen (i.e., "usual care"). The study's primary endpoints were risk of colorectal cancer and related death.

Of the participants in the group invited to screen, 42% underwent screening. After a median follow-up of 10 years, 259 colorectal cancer cases were diagnosed in the invited group compared to 622 cases in the usual care group. The risk of colorectal cancer at 10-year follow-up was dramatically lower in the group invited to screen at 0.98% compared to 1.2% in the usual care group, a reduction of 18%, according to the investigators.

Risk of death from colorectal cancer was 0.28% in the invited group and 0.31% in the usual care group. The number of individuals needed to invite to undergo screening in order to prevent one colorectal cancer was 455, the team found.

"In this randomized trial, the risk of colorectal cancer at 10 years was lower among participants who were invited to undergo screening colonoscopy than among those who were assigned to no screening," the researchers concluded.