Long-Term Efficacy of Sigmoidoscopy in the Reduction of Colorectal Cancer Incidence

• Published in: JNCI : Journal of the National Cancer Institute Vol. 95; no. 8; pp. 622 - 625
• Main Authors: Newcomb, Polly A., Storer, Barry E., Morimoto, Libby M., Templeton, Allyson, Potter, John D.
• Format: Journal Article
• Language: English
• Published: Cary, NC Oxford University Press 16.04.2003; Oxford Publishing Limited (England)
• Subjects: Adult; Aged; Biological and medical sciences; Colorectal cancer; Colorectal Neoplasms - epidemiology; Colorectal Neoplasms - prevention & control; Digestive system. Abdomen; Effectiveness; Endoscopy; Female; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Incidence; Investigative techniques, diagnostic techniques (general aspects); Male; Mass Screening - methods; Mass Screening - standards; Medical sciences; Medical screening; Middle Aged; Odds Ratio; Sigmoidoscopy; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Time Factors; Tumors; Washington - epidemiology; United States; North America; America; Washington; Human; Rectal disease; Sigmoidoscopy; Colorectal cancer; Malignant tumor; Case control study; Medical screening; Epidemiology; Long term; Incidence; Colonic disease; Cancerology; Digestive diseases; Intestinal disease; Endoscopy; Public health
• ISSN: 0027-8874; 1460-2105
• DOI: 10.1093/jnci/95.8.622

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.