Colonoscopy Protects Against Colorectal Cancer for as Long as 20 Years

A previous case-control study conducted in Germany showed that colonoscopy protects against colorectal cancer (CRC) for ≥10 years (JW Gastroenterol Oct 27 2006). Now, the same investigators have conducted a larger study involving 1692 patients with CRC and 1896 population controls recruited from 22 hospitals and population registers in Germany between 2003 and 2007. They used medical records and interviews to determine participants' history of colonoscopy.

After a single negative colonoscopy, the age- and sex-adjusted odds ratios for CRC at the following intervals were 0.14 (1–2 years), 0.10 (3–4 years), 0.26 (5–9 years), 0.36 (10–19 years), and 0.41 (≥20 years). Risks were reduced similarly in men and women. Risks were also reduced in those…