Colon Age Tool Assesses Early-Onset Colorectal Cancer Risk in Male Veterans

As colorectal cancer (CRC) rates continue to rise among adults younger than 50 years, a new study explored the potential of the Colon Age tool to improve screening uptake.¹ Through interviews with patients and primary care providers, researchers found that the concept was widely accepted and may serve as a practical aid in identifying at-risk individuals and prompting timely discussions about screening.

This qualitative study is published in BMC Primary Care.

Patients and providers find the Colon Age tool acceptable and useful for individualizing colorectal cancer risk and encouraging earlier screening, study finds. | Image credit: Africa Studio - stock.adobe.com

“The Colon Age tool is unique in its output of individualized risk, expressing risk in terms of estimated age of the person’s colon, which can drive a discussion about the need for a certain type of CRC screening,” wrote the researchers of the study. “Although many CRC risk scoring systems exist, we have a limited understanding of the utility and acceptability of these scoring systems in practice.”

CRC is increasingly diagnosed in adults younger than 50, with rates rising about 3% annually.² Key contributors include poor dietary patterns, rising obesity and sedentary lifestyles, and disruptions to the gut microbiome—often tied to early-life exposures. Delayed diagnoses and limited screening access in younger adults also play a role. Environmental and epigenetic factors, such as pollution and endocrine-disrupting chemicals, may further increase risk.

The researchers recruited a sample of average-risk male veterans aged 35 to 49 years during routine primary care visits, with permission from their providers.¹ Primary care providers were invited to participate via email. After obtaining informed consent, 2 interviewers—uninvolved in the development of the Colon Age tool—conducted semistructured interviews to explore perceptions of the tool’s acceptability, feasibility, and clinical utility. Interviews were audio-recorded, transcribed, and deidentified.

A total of 31 interviews were conducted, including 23 male veteran patients (mean [SD] age, 47 [4.9] years) and 8 primary care providers (53 [9.8] years). Patients expressed general willingness to follow screening recommendations from their providers, though most were unaware of CRC screening options beyond colonoscopy, such as fecal immunochemical test (FIT). However, they accepted the Colon Age tool when presented with appropriate privacy measures and found it easy to understand, informative, and empowering in personal health decisions.

Providers saw potential for the tool to support screening uptake, facilitate shared decision-making, and personalize care, but raised concerns about its validation, consistency with guidelines, and the feasibility of using it during time-limited appointments.

Both groups agreed the tool could help determine whether patients should undergo colonoscopy or FIT based on their individualized Colon Age, which ranged in examples from low risk (age 35 to 39) to high risk (age 80 to 84), with corresponding recommendations from deferring screening to immediate colonoscopy. Providers also emphasized the need for the tool to be integrated into the electronic health record system, citing challenges with time and “alert fatigue,” while some highlighted the value of precision medicine tools that foster more effective patient-provider communication. Importantly, patients consistently expressed willingness to undergo screening and believed the Colon Age tool could enhance their understanding and engagement, supporting future feasibility studies aimed at improving early detection and screening adherence in younger adults.

However, the researchers noted some limitations. First, the study was conducted at a single Veterans Affairs (VA) Medical Center in the Midwest, and all participating patients were male veterans. As a result, the findings may not be generalizable to non-veteran populations, female patients, or providers practicing outside the VA system. Additionally, while the Colon Age tool showed promise in facilitating shared decision-making, it was based on a risk prediction model with only modest discriminatory ability. Moreover, the thresholds used to guide screening recommendations were derived from the Surveillance, Epidemiology, and End Results database, selected by the tool’s developers, which may have limited clinical precision and consistency with established guidelines.

Despite these limitations, the researchers believe the study provides insights into the Colon Age tool’s acceptability and utility from both patient and provider perspectives.

“As early-onset cases of CRC continue to rise, a risk prediction model like the Colon Age tool, acceptable to both patients and providers, could positively impact patient perceptions and attitudes towards CRC screening,” wrote the researchers. “Providers and patients in this study reached a consensus that the Colon Age tool could improve uptake of CRC screening through individualized risk assessment and decision-making needed in the primary care setting.”

References

1. Imperiale TF, Cheng M, Thomas MR, et al. A qualitative study of a new metric for estimating early-onset colorectal cancer risk in male veterans: "Colon Age". BMC Prim Care. 2025;26(1):226. doi:10.1186/s12875-025-02854-6

2. Steinzor P. 5 reasons why colorectal cancer may be rising in young adults. AJMC^®. June 27, 2025. Accessed July 16, 2025. https://www.ajmc.com/view/5-reasons-why-colorectal-cancer-may-be-rising-in-young-adults