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Colorectal cancer and the power of genetic testing in routine oncology practice

16 Oct 2025

Hereditary cancer genetic testing can help tailor the treatment journey for patients with colorectal cancer, yet it remains underused.1-3 This is a missed opportunity in your cancer care management, especially when testing can directly influence treatment, screening, and family risk assessment.1-2 

The current state of genetic testing in colorectal cancer 

There are over 1 million colorectal cancer survivors in the U.S., but most have not had hereditary cancer genetic testing, even though it’s often covered by insurance. 4-6 

  • 1 in 7 patients with colorectal cancer have an inherited gene variant that increases cancer risk.1,2,7 
  • Only 6% of patients with colorectal cancer receive hereditary cancer genetic testing3

Why hereditary cancer genetic testing matters in patients with and at-risk for colorectal cancer1,2, 8-10 

  1. It helps guide treatment: Patients with advanced disease may benefit from targeted therapies based on their genetic profile. Hereditary cancer genetic testing can identify variants that warrant follow-up testing of the tumor to confirm targeted therapy eligibility.  
  2. It may impact surgical decisions: In some cases, knowing a patient has Lynch syndrome may influence the extent of surgery (e.g., opting for a more comprehensive colectomy to reduce future cancer risk).  
  3. It informs screening: Genetic results can help determine when to start colonoscopies and how often to repeat them. For patients with Lynch syndrome, earlier and more frequent screenings can potentially be life-saving. 
  4. It protects families: Genetic testing can identify colorectal and other cancer risks for siblings, children, and other relatives, giving them the chance to take preventive action.

Why it’s underutilized 

Despite its benefits, genetic testing is still not standard practice for many patients with colorectal cancer. Common reasons include:11 

  • Misconceptions that family history is required 
  • Lack of awareness among providers 
  • Time constraints in busy oncology practices

What oncologists can do 

  • Normalize genetic testing: Make it a routine part of diagnosis and treatment planning. 
  • Educate patients: Explain how results can impact their care and their family’s health. 
  • Collaborate with genetic counselors: Streamline referrals and follow-up.

What patients should know about hereditary cancer genetic testing in colorectal cancer 

You don’t need a family history to benefit from genetic testing. Many people with hereditary cancer variants are the first in their family to be diagnosed. Testing can help you: 

  • Understand the origins of your cancer  
  • Make informed decisions about treatment 
  • Protect your loved ones 

The future of colorectal cancer care 

Colorectal cancer care is evolving—and hereditary cancer genetic testing should be part of that evolution. It’s a simple step that can lead to smarter, more personalized care for patients and their families. 

If you’re an oncologist, it’s time to make genetic testing a routine part of your care strategy. 

If you’re a patient with colorectal cancer, ask your doctor if testing is right for you—even if you don’t have a family history. To learn more about genetic testing, watch our educational video.

References

  1. Coughlin SE, et al. JCO Precis Oncol. 2022:e2200517.  
  2. Uson Jr PLS, et al. Clin Gastroenterol and Hepatology. 2021;e508 – e528. 
  3. Kurian AW, et al. JAMA. 2023;330(1):43–51. 
  4. Moretz C, et al. JAMA Netw Open. 2022;5(10):e2238167. 
  5. Hampel H, et al. Cancer Prev Res (Phila). 2011;4(1):1–5. 
  6. Miller KD, et al. CA A Cancer J Clin. 2022;72(5):409–436. 
  7. Muller C, et al. Gastroenterology. 2020;158 (2):441-446. 
  8. Hodan R, et al. J Natl Compr Canc Netw. 2024;22:695–711. 
  9. Natarajan N, et al. Dis Colon Rectum. 2010;53 (1): 77-82. 
  10. Parry S, et al. Gut.  2011;60(7): 950-7. 
  11. Rodgers-Fouche L, et al. JCO Precis Oncol. 2023;7, e2300440.