#283 CRC Screening: USPSTF Update with Dr. Michael Barry

July 5, 2021 | By Elena Gibson

Review of new 2021 screening guidelines for Colorectal Cancer

Review the 2021 USPSTF Guidelines on Colorectal Cancer Screening (CRC screening) with our guest, Dr. Michael Barry (vice-chair of the U.S. Preventive Services Task Force). Topics include a breakdown of testing modalities (stool tests versus direct visualization), screening ages, what to do for patients older than 75, and more!  

Claim CE credit at curbsiders.vcuhealth.org. It’s free for all healthcare professionals!

Credits

• Written and Produced by: Elena Gibson MD 
• Cover Art and Infographic: Elena Gibson MD
• Hosts: Stuart Brigham MD; Matthew Watto MD, FACP; Paul Williams MD, FACP  
• Reviewer: Matthew Watto MD 
• Editor: Matthew Watto MD (written materials); Clair Morgan of nodderly.com
• Guest: Michael Barry MD 

Episodes | Subscribe | Spotify | Swag! | Top Picks | Mailing List | thecurbsiders@gmail.com | Free CME!

Sponsor: Indeed indeed.com/internalmedicine

CME Partner: VCU Health CE

The Curbsiders are partnering with VCU Health Continuing Education to offer FREE continuing education credits for physicians and other healthcare professionals. Visit curbsiders.vcuhealth.org and search for this episode to claim credit.

Show Segments

• Intro, disclaimer, guest bio
• Guest one-liner
• Benefits of CRC screening
• How to choose a testing modality
• Testing in adults over 75 years old
• Health disparities in CRC screening
• Outro

 USPSTF CRC Screening Update Pearls

1. The 2021 USPSTF guidelines recommend colorectal cancer (CRC) screening for average risk adults ages 45 to 75 years old
2. Selective screening is recommended for adults 76 to 85 years old based on overall health, prior screening history, and patient preferences. 
3. CRC is the third leading cause of cancer-related deaths in the United States (CDC fact sheet)
4. An estimated 10.5% of new CRC cases occur in patients less than 50 years old (Siegel, 2017)
5. Direct visualization screening options include colonoscopy (every 10 years), CT colonography (every 5 years), flexible sigmoidoscopy (every 5 years), and flexible sigmoidoscopy + fecal immunochemical test (FIT) (every 10 years).  
6. Stool-based screening options include high-sensitivity FOBT (yearly), FIT (yearly), and sDNA + FIT (every 1 to 3 years). 
7. The screening method should be chosen based on patient preference, and it is okay to switch between screening methods (expert opinion)
8. The USPSTF guidelines for CRC screening do not apply to patients with a personal history of CRC or adenomas or a personal or family history of high-risk genetic conditions. 

USPSTF CRC Screening 2021 Update Notes 

Overall Recommendation 

The 2021 USPSTF CRC Screening guidelines recommend CRC screening for average risk adults (USPSTF 2021): 

• 45-75 years: screen
• 76-85 years: selective screening based on overall health, prior screening history, and patient preferences. 

**These recommendations do not apply to patients with a prior history of CRC, adenomatous polyps or personal/family history of high-risk genetic disorders. 

Why Screen? 

CRC is the third leading cause of cancer-related deaths in the United States. In 2021, 53,000 deaths due to CRC are estimated in the United States. Dr. Barry uses an example of 1000 people to describe the USPSTF analysis for the benefit of CRC screening on CRC incidence and mortality. 

Example: Imagine a group of 1000 people at age 40 representing the diversity of race, ethnicity and gender in the country. Think about what might happen to them over time. If we don’t screen them our model suggests we would see about 80/1000 develop CRC and roughly 30/1000 would die of CRC. When collectively applied to the United States population this adds up to 53,000 deaths. 

45 is the new 50  

Dr. Barry describes three lines of evidence that led to decreasing the recommended age of screening initiation for CRC from 50 in 2016 (USPSTF 2016) to 45 in 2021.  

1. Changing epidemiology. Due to screening efforts, the incidence of CRC has been dropping for adults greater than 50 years old. However,  for adults in their 40s, the incidence has increased by 15% over the last 15 years or so. Currently, approximately 10.5% of new CRC cases are diagnosed before age 50 (Siegel, 2017).
2. Study participants. Trials used to support screening methods included adults less than 50 years old (Faivre 2004; Kronborg 2004; Scholefield 2012).
3. Modeling: Modeling completed by the  CISNET group supported by the National Cancer Institute supported a decrease in age of screening initiation from 50 to 45. 

Back to Dr. Barry’s 1000 person cohort example: With no screening, 80 cases of CRC and about 30 deaths would be expected over time. With regular screening for CRC starting at age 50, the number of cases would be expected to decrease from 50 to 30 and expected deaths would decrease from 30 to 5 out of 1000. This assumes perfect adherence to screening. By dropping the age of screening initiation to 45, the incidence would be expected to decrease by 2 to 3 additional cases and the number of deaths by one. So, most of the benefit comes from screening initiation at age 50 (grade A recommendation with high certainty of net benefit). And there is moderate certainty of a moderate benefit for screening initiation at age 45 (hence grade B recommendation). For practical purposes, A and B are the same = just do it. 

CRC Screening methods 

The best screening method is the one the patient will complete and preferences vary. The USPSTF recommends the following screening choices (USPSTF 2021): 

1) Direct Visualization: colonoscopy (every 10 years), CT colonography (every 5 years), flexible sigmoidoscopy (every 5 years), flexible sigmoidoscopy + fecal immunochemical test (FIT) (every 10 years)  

2) Stool-based tests: high-sensitivity FOBT (yearly), FIT (yearly), sDNA + FIT (every 1 to 3 years) 

How to choose? 

The colonoscopy is the most sensitive option for a single test, but prevention is similar between testing methods with adherence (USPSTF 2021). Dr. Barry describes how some patients like the idea of getting a colonoscopy and not having to think about it again for 10 years. While others find a colonoscopy (and the prep!) invasive and prefer stool-based testing. It is important to ensure patients understand a follow up colonoscopy will be indicated if a stool-based test is positive. Following a positive stool-based test, a colonoscopy must be completed to ensure the benefits of screening (USPSTF 2021). With stool-based testing, <10% of patients will have a finding that requires colonoscopy.  The screening method should be chosen based on patient preference, and Dr. Barry indicated that it is reasonable to switch between screening methods if necessary.

Links

1. USPSTF 2021 CRC Screening Recommendations
2. Tropical House music – Elena’s pick 

Goal

Listeners will review the updated 2021 USPSTF colorectal cancer (CRC) screening guidelines. 

Learning objectives

After listening to this episode listeners will…  

1. Define the incidence and prevalence of CRC in the United States 
2. Review the updated USPSTF guidelines for CRC screening 
3. Review recommended screening modalities for CRC screening
4. Identify potential pros and cons (or advantages/disadvantages) of various screening modalities

Disclosures

Dr Barry was previously a principle investigator at Healthwise (a non-profit) supported by a grant from MGH. The Curbsiders report no relevant financial disclosures. 

Citation

Gibson EG, Barry MB, Williams PN, Watto MF. “#283 CRC Screening: USPSTF Update with Dr. Michael Barry”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/episode-list Final publishing date July 5, 2021.