Could earlier colorectal cancer screening help identify more people with hereditary cancer?

American Cancer Society colon cancer screening guidelines.

45 is the new 50 when it comes to colorectal cancer screening.

Multiple professional societies have joined the American Cancer Society (ACS) in publishing guidelines for earlier colorectal cancer screening in the general population. These include the US Multisociety Task Force (USMSTF), US Preventive Services Task Force (USPSTF) and the National Comprehensive Cancer Network (NCCN). 

But did you know that starting screening at age 45 could also help identify patients and families who are at high risk due to hereditary colorectal cancer syndromes?

According to the US Census Bureau, more than 20 million people are in the 45-49 age group included in these recommendations. While most are considered to be at average risk, some may ultimately be identified as having a hereditary cancer syndrome.

As with any change in recommendations, primary care providers and GI specialists will be asking, "Will this affect my practice?" "...and, how?"

Catching cancer early

Imagine your patient, Heather. She is a healthy 46 year old who arrives for her annual checkup. Based on the new guideline, you arrange for her to do a fecal occult blood test, which tests positive for blood. An adenomatous polyp is removed from the right colon during follow-up colonoscopy. Pathology detects a small focus of carcinoma arising within the polyp. You find this result concerning, but are relieved the cancer was found at a very early stage.

There is a worrying trend – colorectal cancer diagnoses are increasing in younger people like Heather. USPSTF states that approximately 10.5% of new CRC cases occur in those under 50, and the ACS determined that including 45-49 year olds in screening will save lives. The goal is to reduce the complications of, or deaths from, CRC in this demographic.

We don’t know all the reasons a young person may develop CRC, as not all will have traditional risk factors such as obesity and smoking. Heather’s diagnosis at such a young age is a red flag for Lynch syndrome, the most common form of hereditary colorectal cancer. She is a candidate for further evaluation and possible genetic testing.

Identify patients at increased or high risk to personalize management

Incorporating current screening guidelines into your practice is only one of the ways to identify which of your patients are at risk. When available, family history continues to be a valuable tool. Perhaps a structured family history would have revealed Heather’s risk even earlier. Family history assessment can help to stratify your patients into average, increased or high risk categories, personalizing care based on the level of risk. Do you have a system to integrate family history collection into your practice? Do you know what information is most important, and what to do with this once you’ve collected it?

Look for genetic red flags so you can identify individuals at increased or high risk of CRC:

  • Early onset (< 50 years) colorectal cancer, for your patient or a first- or second-degree relative
  • Early onset advanced adenomatous colorectal polyp (> 1 cm, confirmed by pathology)
  • Multiple relatives with the same or associated cancers (colon, rectal, endometrial, gastric, small bowel, ovarian, urothelial, biliary tract, pancreatic, brain [usually glioblastoma] and/or sebaceous cancers) on the same side of the family
  • Multifocal (multiple primaries)
  • Individual with greater than 10 adenomatous colorectal polyps (confirmed), or polyps with unusual histology
  • Known genetic syndrome in family

A personal or family history with these red flags indicates a patient is at high risk of a hereditary syndrome like Lynch syndrome. If you’ve collected family history in sufficient detail and did not find these red flags, other factors such as a first-degree relative with CRC or advanced adenoma at any age would stratify your patient into an increased risk category, and more frequent colonoscopies may be indicated. 

Accessing genetic services for high risk patients

Determining whether an individual is at risk of hereditary colorectal cancer can be complex. There are both established criteria for making a clinical diagnosis and recommendations for when an individual should be referred to a genetic expert for further work-up and, potentially, testing. The genetic expert can perform a comprehensive cancer risk assessment based on the patient’s personal cancer or polyp history and family history, and when appropriate, facilitate informed decision-making about genetic testing, navigate the changing genetic testing landscape, and interpret results in context of the personal and family history. The genetic expert can also help patients understand and adapt to the medical, psychological and familial implications of genetic contributions to disease.

General resources

Genetic counselors, clinical geneticists, and nurse specialists in genetics may be available at your institution or elsewhere. You can find a genetic specialist through:

Bottom line

The incidence of colorectal cancer is increasing in young adults in the U.S. To address this concerning trend, multiple professional societies have updated their screening guidelines to include this younger population. The recommendation for earlier screening, beginning at age 45, will certainly impact your practice, and is expected to have a positive impact on your patients’ health. Results of this screening will also, in some cases, assist in identifying patients and families at risk of a hereditary colon cancer syndrome such as Lynch syndrome.

In addition to the results from CRC screening, family history information will help you assess your patients’ level of risk for hereditary cancer. Identifying whether a person is at average, increased or even high risk from a hereditary syndrome will allow you to develop an individualized management plan.

Learn more

There are resources available to help you identify which patients may be at increased or high risk.

Interested to learn more about cancer and genetics? Follow us on Twitter @JAXClinicalEd.


Montminy EM, Zhou M, Maniscalco L, et al. Contributions of adenocarcinoma and carcinoid tumors to early-onset colorectal cancer incidence rates in the United States. Ann Intern Med. 2021;174(2):157-166.

National Comprehensive Cancer Network (2021). Genetic/Familial High Risk Assessment Guidelines: Colorectal. Retrieved 3/17/2022  from (free registration required)

Patel SG, May FP, Anderson JC, Burke CA, Dominitz JA, Gross SA, Jacobson BC, Shaukat A, Robertson DJ. Updates on age to start and stop colorectal cancer screening: recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer. Gastrointest Endosc. 2022 Jan;95(1):1-15. 

US Census Bureau (2020). American Community Survey. Age and Sex. Retrieved 3/17/2022 from

US Preventive Services Task Force, Davidson KW, Barry MJ, Mangione CM, Cabana M, Caughey AB, Davis EM, Donahue KE, Doubeni CA, Krist AH, Kubik M, Li L, Ogedegbe G, Owens DK, Pbert L, Silverstein M, Stevermer J, Tseng CW, Wong JB. Screening for Colorectal Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021 May 18;325(19):1965-1977. 

Wolf AM, Fontham ET, Church TR, et al. Colorectal cancer screening for average-risk adults: 2018 guideline update from the American Cancer Society CA: A Cancer Journal for Clinicians. 2018; 68(4):250-281.