(HealthDay News) — Screening with flexible sigmoidoscopy correlates with significant reductions in the incidence of distal and proximal colorectal cancer and in distal colorectal cancer mortality, according to a study published online May 21 in the New England Journal of Medicine to coincide with presentation at the annual Digestive Disease Week, held from May 19 to 22 in San Diego.
To compare the effect of screening with flexible sigmoidoscopy with usual care on colorectal cancer incidence and mortality, Robert E. Schoen, M.D., M.P.H., from the University of Pittsburgh, and colleagues conducted a randomized trial from 1993 to 2001, which included 154,900 adults aged 55 to 74 years.
The researchers found that 83.5 percent of the 77,445 participants in the intervention group underwent baseline screening, and 54.0 percent underwent a repeat screen at three to five years. After a median follow-up of 11.9 years, there was a 21 percent decrease in the incidence of colorectal cancer in the intervention versus usual-care group (11.9 versus 15.2 cases per 10,000 person-years, respectively). The incidence of both distal and proximal colorectal cancer was significantly reduced (relative risk [RR], 0.71 and 0.86, respectively). There was a 26 percent reduction in mortality in the intervention group compared with the usual-care group (2.9 versus 3.9 deaths per 10,000 person-years). In the intervention group, mortality from distal colorectal cancer was significantly reduced (RR, 0.50), but mortality from proximal colorectal cancer was unaffected (RR, 0.97; 95 percent confidence interval, 0.77 to 1.22).
“Screening with flexible sigmoidoscopy was associated with a significant decrease in colorectal-cancer incidence (in both the distal and proximal colon) and mortality (distal colon only),” the authors write.
Several study authors and the editorial author disclosed financial ties to the pharmaceutical and biotechnology industries.