Early-onset Colorectal Cancer Screening: What’s New and What Should We Do?

Colorectal cancer (CRC) is the third largest cause of death from cancer-related causes in the United States. Screening programs lower the incidence and mortalities of CRC in those aged 50 and above with an average risk for the disease. On the other hand, the incidence of CRC in people younger than 50 years of age (early-onset colorectal cancer, or eoCRC) has recently increased substantially. Epidemiologic studies of eoCRC suggest that the cancer is most prevalent in the distal colon and rectum and is associated with several modifiable risk factors, such as diabetes, obesity, diet, sedentary lifestyle, alcohol intake, and smoking. The data covering the potential risk factors of prior antibiotic exposure and alterations to the microbiome or direct carcinogen exposure are still being gathered. Delayed diagnosis or more aggressive tumor biology may lead to aggressive clinicopathologic characteristics of eoCRC observed at presentation. When matched for stage, the outcomes of patients with eoCRC are comparable to those of patients with later-onset CRC; nevertheless, the overall mortality rate is higher due to a higher frequency of advanced illness at a younger presentation, which results in more life years lost.