How often should adults be screened for colorectal cancer starting at age 45?

The recommended screening interval for colorectal cancer in adults starting at age 45 is every 10 years with a colonoscopy for those at average risk. This guideline is based on evidence indicating that regular screening can significantly reduce morbidity and mortality associated with colorectal cancer. Colonoscopy allows for both the detection and removal of precancerous polyps, making it one of the most effective methods of screening.

While there are other screening methods available, such as virtual colonoscopy and stool-based tests, the colonoscopy offers a more comprehensive evaluation of the colon and rectum. Additionally, individuals considered high-risk may require more frequent screenings or different methods, but for those at average risk, the 10-year interval is established as optimal for balancing efficacy and the burden of screening.

Screening every year with blood tests, every 5 years with virtual colonoscopy, or every 3 years with physical exams do not align with current guidelines and may not provide the same level of protection against colorectal cancer as the 10-year colonoscopy approach.