Systematic review with meta‐analysis: the comparative effectiveness of aspirin vs. screening for colorectal cancer prevention

Abstract

Summary Background Both aspirin use and screening with flexible sigmoidoscopy or guaiac faecal occult blood testing (FOBT) may reduce mortality from colorectal cancer, but comparative effectiveness of these interventions is unknown. Aim To compare aspirin to guaiac FOBT screening with regard to incidence and mortality of colorectal cancer in a network meta‐analysis. Methods We searched Medline, EMBASE and the COCHRANE central register (CENTRAL) for relevant randomised trials identified until 31 October 2015. Randomised trials in average‐risk populations that reported colorectal cancer mortality, colorectal cancer incidence, or both, with a minimum follow‐up of 2 years, and more than 100 randomised individuals were included. Three investigators independently extracted data. We calculated relative risks [RR with 95% predictive intervals (PrIs)] for the comparison of the interventions by frequentist network meta‐analyses. Results The effect of aspirin on colorectal cancer mortality was similar to FOBT (RR 1.03; 95% PrI 0.76–1.39) and flexible sigmoidoscopy (RR 1.16; 95% PrI 0.84–1.60). Aspirin was more effective than FOBT (RR 0.36; 95% PrI 0.22–0.59) and flexible sigmoidoscopy (RR 0.37; 95% PrI 0.22–0.62) in preventing death from or cancer in the proximal colon. Aspirin was equally effective as screening in reducing colorectal cancer incidence, while flexible sigmoidoscopy was superior to FOBT (RR 0.84; 95% PrI 0.72–0.97). Conclusions Low‐dose aspirin seems to be equally effective as flexible sigmoidoscopy or guaiac FOBT screening to reduce colorectal cancer incidence and mortality, and more effective for cancers in the proximal colon. A randomised comparative effectiveness trial of aspirin vs. screening is warranted.

The risk of lower gastrointestinal bleeding in low‐dose aspirin users

“…Our results revealed that low‐dose ASA users are at an increased risk of LGIB. In addition to the prevention of thromboembolic diseases, a recent systemic review with meta‐analysis suggested that low‐dose ASA is as effective as flexible sigmoidoscopy or guaiac faecal occult blood testing in colorectal cancer prevention . With the increasing use of low‐dose ASA, patients requiring this antiplatelet therapy should be informed about its adverse effects on the lower gastrointestinal tract.…”

Exclusive and Combined Use of Statins and Aspirin and the Risk of Pancreatic Cancer: a Case-Control Study

“…Its chemopreventive role is well recognized for many cancer types 7 particularly colorectal cancer (CRC) 8,9 .…”

General Aspects of Primary Cancer Prevention

“…Daily aspirin for at least 5 years reduced the risk of CRC after a latent period of about 7 years, while benefit increased with scheduled duration of treatment [48]. Another important meta-analysis investigated the effectiveness of aspirin versus screening for CRC and concluded that aspirin reduced CRC mortality by 19% compared to placebo [49]. Moreover, low-dose aspirin seems to be equally effective as flexible sigmoidoscopy or guiacfecal occult blood test screening to reduce CRC incidence and mortality, while low-dose aspirin was more effective for cancers in the proximal colon [49].…”

“…Another important meta-analysis investigated the effectiveness of aspirin versus screening for CRC and concluded that aspirin reduced CRC mortality by 19% compared to placebo [49]. Moreover, low-dose aspirin seems to be equally effective as flexible sigmoidoscopy or guiacfecal occult blood test screening to reduce CRC incidence and mortality, while low-dose aspirin was more effective for cancers in the proximal colon [49]. However, aspirin is not effective in all individuals with an average risk for CRC.…”