Don't Wait for Symptoms: A Guide to Colon Cancer Screening at Any Age

Colon cancer is showing up more often, and in younger people too. Because of this, doctors now say most people should start screening at age 45, even if they feel fine and have no family history. In fact, about 3 out of 4 people who get colon cancer have no family history of it, so being “low risk” does not mean you can skip screening ^[1,2].

You have choices. At-home stool tests are easy and can be done in the bathroom. The oldest, the fecal occult blood test (FOBT), looks for hidden blood but means you have to avoid red meat, vitamin C, and pain pills like ibuprofen for a few days so the test is not falsely positive. The newer fecal immunochemical test (FIT) also looks for blood but needs no special diet. Cologuard goes a step further and looks for abnormal DNA from cancer cells as well as blood. These tests are helpful, but they mostly find cancer that is already there — they are not good at finding the growths that turn into cancer later. They also only work if you keep repeating them (FIT every year, Cologuard every 3 years), and if any of them are positive, you still need a colonoscopy ^[3,4].

A colonoscopy is different because it can actually lower your chance of ever getting colon cancer. During the test, the doctor can find and remove small growths called polyps before they have a chance to turn into cancer. Studies show that removing these polyps greatly cuts the risk of getting colon cancer and dying from it ^[5,6]. Stool tests cannot do this. If you have a higher risk — such as a family history, inflammatory bowel disease, or a genetic condition — a colonoscopy is usually the better choice ^[7]. Talk with your doctor about which option fits you best. The most important thing is to get screened.

References

1. US Preventive Services Task Force. Screening for Colorectal Cancer: US Preventive Services Task Force Recommendation Statement. JAMA. 2021.
2. Patel SG, et al. Updates on Age to Start and Stop Colorectal Cancer Screening: Recommendations From the U.S. Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol. 2022.
3. Carethers JM. Stool-Based Screening Tests for Colorectal Cancer. JAMA. 2023.
4. Imperiale TF, et al. Next-Generation Multitarget Stool DNA Test for Colorectal Cancer Screening. N Engl J Med. 2024.
5. Zauber AG, et al. Colonoscopic Polypectomy and Long-Term Prevention of Colorectal-Cancer Deaths. N Engl J Med. 2012.
6. Winawer SJ, et al. Prevention of Colorectal Cancer by Colonoscopic Polypectomy. N Engl J Med. 1993.
7. American Cancer Society Guidelines for the Early Detection of Cancer. 2023.