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Meta-Analysis
. 2014 Dec 28;20(48):18466-76.
doi: 10.3748/wjg.v20.i48.18466.

Reduced incidence and mortality from colorectal cancer with flexible-sigmoidoscopy screening: a meta-analysis

Jennifer Shroff  1 , Nirav Thosani  1 , Sachin Batra  1 , Harminder Singh  1 , Sushovan Guha  1
Affiliations
Meta-Analysis

Reduced incidence and mortality from colorectal cancer with flexible-sigmoidoscopy screening: a meta-analysis

Jennifer Shroff et al. World J Gastroenterol. .

Abstract

Aim: To conduct a systematic review and meta-analysis of published population-based randomized controlled trials (RCTs).

Methods: RCTs evaluating the difference in mortality and incidence of colorectal cancer (CRC) between a screening flexible sigmoidoscopy (FS) group and control group (not assigned to screening FS) with a minimum 5 years median follow-up were identified by a search of MEDLINE and EMBASE databases and the Cochrane Central Register for Controlled Trials through August 2013. Random effects model was used for meta-analysis.

Results: Four RCTs with a total of 165659 patients in the FS group and 249707 patients in the control group were included in meta-analysis. Intention-to-treat analysis showed that there was a 22% risk reduction in total incidence of CRC (RR = 0.78, 95%CI: 0.74-0.83), 31% in distal CRC incidence (RR = 0.69, 95%CI: 0.63-0.75), and 9% in proximal CRC incidence (RR = 0.91, 95%CI: 0.83-0.99). Those who underwent screening FS were 18% less likely to be diagnosed with advanced CRC (OR = 0.82, 95%CI: 0.71-0.94). There was a 28% risk reduction in overall CRC mortality (RR = 0.72, 95%CI: 0.65-0.80) and 43% in distal CRC mortality (RR = 0.57, 95%CI: 0.45-0.72).

Conclusion: This meta-analysis suggests that screening FS can reduce the incidence of proximal and distal CRC and mortality from distal CRC along with reduction in diagnosis of advanced CRC.

Keywords: Colorectal Cancer; Flexible sigmoidoscopy; Incidence; Meta-analysis; Mortality; Randomized control trials.

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Figures

Figure 1
Figure 1
Scheme for study selection process. RCT: Randomized controlled trial; FOBT: Fecal occult blood testing.
Figure 2
Figure 2
Forrest plots depicting incidence of total colorectal cancer (A), distal colorectal cancer (B), and proximal colorectal cancer (C). CRC: Colorectal cancer; ITT: Intention to treat; FS: Flexible sigmoidoscopy.
Figure 3
Figure 3
Forrest plots depicting mortality of total colorectal cancer (A), distal colorectal cancer (B), and proximal colorectal cancer (C). CRC: Colorectal cancer; ITT: Intention to treat; FS: Flexible sigmoidoscopy.
Figure 4
Figure 4
Forrest plots depicting incidence of total colorectal cancer in men (A) and women (B). CRC: Colorectal cancer; ITT: Intention to treat; FS: Flexible sigmoidoscopy.
Figure 5
Figure 5
Forrest plot depicting incidence of advanced colorectal cancer. CRC: Colorectal cancer; ITT: Intention to treat; FS: Flexible sigmoidoscopy.
See this image and copyright information in PMC

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