Comment in:
Long-term efficacy of sigmoidoscopy in the reduction of
colorectal cancer incidence.
Newcomb PA, Storer BE, Morimoto LM, Templeton A, Potter JD.
Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center,
Seattle 98109-1024, USA. pnewcomb@fhcrc.org
Screening sigmoidoscopy is associated with a reduction in both the incidence and
mortality of colorectal cancer. Although current guidelines recommend
sigmoidoscopy screening every 5 years, the duration of risk reduction is not
known. We conducted a population-based case-control study to examine the
association between sigmoidoscopy screening and colorectal cancer incidence. We
collected information on screening history and risk factors from case patients
with distal (n = 1026) and proximal (n = 642) colorectal cancer and from 1294
control subjects from October 1998 through February 2002. Screening
sigmoidoscopy was associated with a statistically significant reduction in the
incidence of distal colorectal cancer (odds ratio [OR] = 0.24, 95% confidence
interval [CI] = 0.17 to 0.33). These reductions were sustained for up to 16
years with little attenuation. We also observed strong inverse associations
between cancer incidence and sigmoidoscopy in analyses that included subjects
with symptom-related tests. Current recommendations regarding the frequency of
sigmoidoscopy screening may be unnecessarily aggressive.
PMID: 12697855 [PubMed - indexed for MEDLINE]