The Growing Challenge of Young Adults With Colorectal Cancer.

Although the incidence of colorectal cancer is declining in the overall US population, the rates of colorectal cancer are rising among adolescent and young adult (AYA) patients-defined as individuals under 45 years of age. This population includes patients deemed too young for routine colorectal cancer screening, which in the United States is typically initiated at age 50 for men and women at average risk. Clinicopathologic differences have long been observed between AYAs and older patients with colorectal cancer. In addition, recently available high-throughput DNA sequencing techniques have revealed different rates of genetic alterations between these two groups, indicating potential molecular differences in the disease state and suggesting the need for alternative treatment strategies in younger patients. AYA patients with colorectal cancer often receive more aggressive treatment regimens than their older counterparts, without a corresponding improvement in survival. Furthermore, these younger patients have particular survivorship issues that warrant attention from the oncology community. In this review, we address specific issues pertaining to AYA patients with colorectal cancer, including evaluation for hereditary colorectal cancer syndromes, clinicopathologic and biologic features unique to AYA patients with colorectal cancer, treatment outcomes, and survivorship.