Flexible sigmoidoscopy, which has fewer side effects, requires less bowel preparation, and presents a lower risk of bowel perforation than colonoscopy, is effective in decreasing the rates of new colorectal cancer cases and deaths, according to results from a study that spanned almost 20 years. The study is published online in the New England Journal of Medicine.
“The most important message is that, regardless of modality chosen, colorectal cancer screening lowers mortality from colorectal cancer, and all individuals 50 and over should be screened,” said study author Christine Berg, MD, chief of NCI’s Early Detection Research Group and project officer of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial.
The PLCO trial, a large population-based randomized trial designed to determine the effects of screening on cancer-related mortality, enrolled 154,900 men and women aged 55 through 74. Patients were randomly assigned to receive flexible sigmoidoscopy screening or usual care between 1993 and 2001. Those in the usual care group (ie, control group) received screening only if they or their physician requested it. Participants assigned to the flexible sigmoidoscopy group were screened once upon entering the study (baseline) and subsequently 3 to 5 years later. Researchers followed the patients for approximately 12 years to collect data on cancer diagnoses and deaths.
The researchers compared overall colorectal cancer mortality and incidence in the 2 groups. After an average of almost 12 years, participants in the screening group had a 21% lower incidence of colorectal cancer overall and a 26% lower rate of colorectal cancer mortality than participants in the control group. In other words if 1000 people followed the PLCO practice of 2 sigmoidoscopy screenings over the course of 10 years, there would be approximately 3 fewer new cases and 1 fewer death from colorectal cancer compared with those not receiving regular screenings.
Barnett Kramer, MD, director of NCI’s Division of Cancer Prevention, said, “There are several effective screening tests for colorectal cancer, and the most effective screening test is the one that people choose to take.”
Source: NCI.