Correlation between a sedentary lifestyle and the risk of colon cancer: a systematic review

Sedentary behaviour (prolonged sitting with low energy expenditure) is common in modern life. Emerging research has focused on the harmful consequences of sedentary behaviour, including diabetes, cardiovascular diseases and cancer. However, the association between sedentary behaviour and colon cancer is unclear. To investigate the relationship between sedentary behaviour and the risk of developing colon cancer. Systematic searches of Medline, Embase, Ovid and Google Scholar databases were performed using specific keywords. Publications were screened and quality appraised by two authors based on clearly stated inclusion and exclusion criteria. Critical appraisal was conducted using the Critical Appraisal Skills Programme tools for cohort and case–control studies. Data measuring the association between sedentary behaviour and colon cancer were extracted from included studies. Eight studies were included in this review (six cohort studies and two case–control studies) totalling 2 159 304 patients. A narrative synthesis of findings was performed because of heterogeneity in study designs and measures of exposures to sedentary behaviour. Two studies showed a statistically significant association between total daily sitting time and colon cancer. Three studies found a significant relationship between sedentary work and colon cancer, and three studies revealed a significant correlation between colon cancer and sedentary behaviour at leisure time (watching television). Sedentary behaviour in general is associated with increased risk of colon cancer in both men and women. This association is evident for sedentary behaviour in all settings (home, work and leisure time). It is necessary for future research to use new and validated measures of sedentary behaviour.