Once-only flexible sigmoidoscopy screening between 55 – 64 years reduces colorectal cancer

January 01, 0001

Once-only flexible sigmoidoscopy screening between 55 - 64 years reduces colorectal cancer

Colorectal cancer is the third most common cancer worldwide and has a high mortality rate. The researchers from the UK tested the hypothesis that only one flexible sigmoidoscopy screening between 55 and 64 years of age can substantially reduce colorectal cancer incidence and mortality. This randomised controlled trial was undertaken in 14 UK centres. 170,432 eligible men and women, who had indicated on a previous questionnaire that they would accept an invitation for screening, were randomly allocated to the intervention group (offered flexible sigmoidoscopy screening) or the control group (not contacted). 113,195 people were assigned to the control group and 57,237 to the intervention group, of whom 112,939 and 57,099, respectively, were included in the final analyses. 40,674 (71%) people underwent flexible sigmoidoscopy.

During screening and median follow-up of 11·2 years, 2524 participants were diagnosed with colorectal cancer (1818 in control group vs 706 in intervention group) and 20,543 died (13,768 vs 6775; 727 certified from colorectal cancer, 538 vs 189). In intention-to-treat analyses, colorectal cancer incidence in the intervention group was reduced by 23% (hazard ratio 0.77) and mortality by 31% (0.69). In per-protocol analyses, adjusting for self-selection bias in the intervention group, incidence of colorectal cancer in people attending screening was reduced by 33% (0.67) and mortality by 43% (0.57). Incidence of distal colorectal cancer (rectum and sigmoid colon) was reduced by 50% (0.50). The numbers needed to be screened to prevent one colorectal cancer diagnosis or death, by the end of the study period, were 191 and 489, respectively.

The researchers concluded: "Flexible sigmoidoscopy is a safe and practical test and, when offered only once between ages 55 and 64 years, confers a substantial and longlasting benefit."

This is important in countries where it is available and can be afforded.

For the full abstract, click here.

The Lancet published online 28 April 2010
© Elsevier Ltd 2010
Once-only flexible sigmoidoscopy screening in prevention of colorectal cancer: a multicentre randomised controlled trial. Wendy S Atkin, Rob Edwards, Ines Kralj-Hans et al for the UK Flexible Sigmoidoscopy Trial Investigators. Correspondence to Wendy Atkin: [email protected]

Category: D. Digestive. Keywords: flexible sigmoidoscopy, screening, prevention, colorectal, cancer, randomised controlled trial, journal watch.
Synopsis edited by Dr Stephen Wilkinson, Melbourne, Australia. Posted on Global Family Doctor 14 May 2010

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