- Patients screened with sigmoidoscopy are less likely to develop colorectal cancer within 15 years than unscreened patients.
Why this matters
- Most guidelines recommend rescreening after 5-10 years; it may be safe to extend this interval to 15 years, say researchers.
- Researchers conducted a network meta-analysis of 12 randomized trials comparing colorectal cancer screening using guaiac fecal occult blood test (gFOBT), fecal immunochemical test (FIT), sigmoidoscopy, or colonoscopy in healthy patients aged 50-79 years.
- Funding: Norwegian Research Council.
- On the basis of high-certainty evidence, patients screened with sigmoidoscopy were slightly less likely to be diagnosed with or die from colorectal cancer than those with no screening (relative risk [RR], 0.76 [95% CI, 0.70-0.83] and RR, 0.74 [95% CI, 0.69-0.80], respectively).
- Annual and biennial gFOBT screening had little or no association with colorectal cancer incidence, but it was linked to slightly reduced mortality (annual: RR, 0.69 [95% CI, 0.56-0.86]; biennial: RR, 0.88 [95% CI, 0.82-0.93]).
- Moderate-certainty evidence showed greater effects in men than women for incidence (women: RR, 0.86 [95% CI, 0.81-0.92]; men: RR, 0.75 [95% CI, 0.71-0.79]) and mortality (women: RR, 0.85 [95% CI, 0.71-0.96]; men: RR, 0.67 [95% CI, 0.61-0.75]).
Trials did not provide data on harms and burdens of screening.