Presentation and survival among patients with colorectal cancer before the age of screening: a systematic review and meta-analysis

Background: The incidence of colorectal cancer in North America is rising among patients younger than 50 years. Available data are conflicting regarding presentation and outcomes in this population. This review aimed to synthesize literature regarding young patients with colorectal cancer with respect to patient demographics, disease extent and survival, compared with patients older than 50 years. Methods: We searched Medline, Embase, the Cochrane Central Register of Controlled Trials and PubMed for articles published between 1990 and the time of search. Articles comparing North American patients with colorectal cancer younger and older than 50 years were eligible for inclusion. We used a random-effects model to pool odds ratios. Results: Eight retrospective studies were eligible for inclusion (n = 790 959). Mean age was 42.6 years (standard deviation [SD] 5.07) in the younger group, and 69.1 years (SD 9.25) in the older group. Young patients were more likely to present with regional (odds ratio [OR] 1.27, 95% confidence interval [CI] 1.16-1.40) and distant disease (OR 1.47, 95%CI 1.30-1.67). Considering patients at all stages of disease, differences in 5-year overall survival (OR 1.54, 95%CI 0.96-2.47) and cancer-specific survival (OR 1.01, 95%CI 0.91-1.13) were not statistically significant between groups. However, when controlling for disease extent, 5-year cancer-specific survival was significantly higher among young patients with local (OR 1.69, 95%CI 1.43-1.99), regional (OR 1.37, 95%CI 1.16-1.63) and distant disease (OR 1.79, 95%CI 1.45-2.21). Conclusion: North American patients presenting with colorectal cancer before the age of 50 years are more likely to have advanced disease. Although overall and cancer-specific survival is not significantly different between these groups, younger patients have improved survival when controlling for cancer stage.