Worrisome Trends in Young-Onset Colorectal Cancer: Now Is the Time for Action

Colorectal cancer (CRC) in the young adult population is of increasing incidence and concern. Since 1994, CRC incidence in individuals younger than 50 years has been increasing by 2% per year. The surge of CRC incidence in young adults is particularly alarming as the overall CRC frequency has been decreasing. Young-onset CRCs are characterized by more advanced stage at diagnosis, poorer cell differentiation, higher prevalence of signet ring cell histology, and left-colon sided location of the primary tumor. Genetic predisposition and heritable syndromes contribute to this trend, but perhaps more concerning is the majority of new diagnoses that involve no traceable genetic risk factors are sporadic. This review provides a summary of key aspects related to colorectal cancer in young adults, including epidemiology, etiology, genetics, clinical difficulties, early diagnosis, and prevention with emphasis on screening age.