A Novel Look at Colorectal Cancer Screening: Mark Fendrick, MD, Supports a Green Approach

Mark Fendrick, MD, professor of internal medicine at the University of Michigan School of Medicine and professor of health management and policy at the university's school of public health has been involved in research to develop, enhance, and refine noninvasive tests to assess for colorectal cancer (CRC) for many years. Most recently he participated in a study that compared the carbon footprints of stool DNA testing and colonoscopy.

In an interview with Patient Care, Fendrick talked about the evolution of choices for CRC screening and the convenience and privacy now offered by home-based stool tests as an option to initiate the screening process. Spoiler alert - the study on greener screening showed "a tremendously lower carbon emission footprint from getting stool DNA [CRC screening] compared to colonoscopy." Fendrick sees the potential, as stool-based tests become more and more accurate, for clinicians and patients to not just have a choice, but to have a green choice when it comes to their next CRC assessment.

Following is a quick take on Fendrick's thoughts

Colorectal Cancer Screening Has a Unique Preventive Benefit

• Compared to other cancers screened in primary care (breast, lung, cervical, prostate), colorectal cancer is unique because it allows prevention through polyp detection and removal.
• Most other cancer screenings focus on early detection, not prevention.

Colorectal Screening Options: Colonoscopy vs Stool-Based Tests

• Colonoscopy:
  • Considered the gold standard.
  • Allows same-day polypectomy.
  • Limited by access, scheduling, and availability of specialists.
• Stool-based tests:
  • Attractive due to convenience (can be done at home).
  • Stool DNA tests (eg, Cologuard) are done every 3 years.
  • FIT and FOBT are annual.
  • 90% of stool tests come back negative, meaning no further action needed.

Environmental Impact is an Emerging Factor in Screening Decisions

• Environmental sustainability is increasingly important to patients.
• A recent study showed that stool DNA testing has a much lower carbon footprint compared to colonoscopy.
  • Ironically, the main source of emissions in the stool DNA strategy was from the follow-up colonoscopies for positive results.
• As stool DNA test accuracy improves, the need for follow-up colonoscopies decreases—making it a “greener” option.

Clinical and Ethical Implications for Primary Care

• Both colonoscopy and stool DNA tests are evidence-based and guideline-supported.
• Primary care clinicians have the flexibility to present multiple options to patients.

The discussion now includes not only clinical effectiveness and convenience, but also environmental considerations.