Colorectal Cancer Screening in Adults: Is Earlier Screening Warranted?

Authors

Aimee S. Larson, University of LynchburgFollow

Specialty

Internal Medicine

Advisor

Laura Witte, PhD, PA-C

Abstract

Despite advancements in cancer research, treatment, and prevention, barriers to screening for certain forms of cancer persist due in part based on outdated recommendations, poor insurance coverage, and socioeconomic factors. The 2018 update to the American Cancer Society (ACS) guidelines for colorectal cancer screening for average-risk adults has been a major topic of discussion among colorectal and digestive health experts. The main change to the guidelines—last updated in 2008—is a qualified recommendation to lower the age at which to start screening from 50 years old to 45 as of 2018. The updated guidelines recommend regular screening with a high-sensitivity stool-based test (e.g., fecal immunochemical test or highly sensitive guaiac-based fecal occult blood test every year) or a structural examination (e.g., colonoscopy every 10 years, or CT colonography or flexible sigmoidoscopy every 5 years), depending on patient preference and test availability, with positive results on non-colonoscopic tests to be followed up with timely colonoscopy.¹ Yet many insurance companies continue to deny coverage for screening before the age of 50 years old in the absence of a defined risk factor, and many primary care providers are still performing inadequate risk screening and counseling.

The recommendations for a lower starting age for screening reflects a growing awareness of the rising incidence of early-onset colorectal cancer. While the incidence of, and mortality from, colorectal cancer in those aged over 50 has decreased in the United States over the past two decades, there has been a 51% increase in colorectal cancer incidence in those under age 50 on a global level. Colorectal cancer incidence and mortality in patients younger than 50 years is increasing, but screening before the age of 50 is not routinely offered in many areas despite ongoing evidence of benefit. Advanced-stage diagnosis and mortality from colorectal cancer before 50 years of age are increasing. This is not a detection-bias effect; it is a real issue affecting the entire population. Three independent computational models indicate that screening from 45 years of age would yield a better balance of benefits and risks than the current start at 50 years of age.²

This article explores various studies and recommendations for early colorectal cancer screenings with consideration for mitigating factors, cost, risks, and alternative screening to diagnostic testing. Widespread data does suggest a growing and disturbing trend in increased colon cancer rates among young adults, though causes remain unclear. The discrepancies lie with how to address this trend to allow for the improved outcomes with screening seen in patients ages 50-75 years.

Recommended Citation

Larson AS. Colorectal Cancer Screening in Adults: Is Earlier Screening Warranted?. University of Lynchburg DMSc Doctoral Project Assignment Repository. 2021; 3(1).