Colorectal cancer and absolute risks

Correspondence to Dr Blake J Lawrence, School of Psychology, Curtin University, Perth, WA 6102, Australia; blake.lawrence@curtin.edu.au We read the umbrella review and meta-analysis by Chapelle et al, 1 which summarised the evidence from 80 meta-analyses examining medications and dietary factors associated with prevention of colorectal cancer. The main findings showed that aspirin, non-steroidal anti-inflammatory drugs, magnesium, folate and high consumption of fruits, vegetables, fibre and dairy products were associated with decreased incidence of colorectal cancer. [...]the estimated global absolute risk of colorectal cancer incidence is 2%.2 When examining whether medications and lifestyle factors are associated with increased or decreased risk of disease incidence (in this case, colorectal cancer) it is important that research findings are reported within the context of the overall absolute risk of disease incidence.3 4 Research findings primarily reported as relative risk associations (such as those by Chapelle et al) provide an estimate of the difference in risk of colorectal cancer incidence between the groups of patients included in each study.