Skip to content
Life Guide U.S. essentials
English

From 45 to 50, start colorectal cancer screening with a fecal immunochemical test for hidden blood in stool, or a colonoscopy

  • Moderate value
  • Evidence A
  • Buys life
  • Disputed
  • For: Age 35+
  • Costs a little
  • Takes some hours
  • No willpower

In plain words

A stool blood test that costs a few dozen CNY, done every year or two, lowers the chance of dying of colorectal cancer by about 16%, and by 25% for people who completed at least one round. For people invited to have one colonoscopy, the chance of getting colorectal cancer over the next 10 years falls from 1.20% to 0.98%.

Cost

A stool test costs a few dozen CNY, done every 1 to 2 years. A colonoscopy costs a few hundred to over a thousand CNY, and with a negative result every 10 years is enough. Set aside a day for bowel prep before a colonoscopy.

What you get

Cochrane pooled several studies. People who had fecal occult blood screening had about a 16% lower risk of dying of colorectal cancer (RR 0.84; 95% CI 0.78 to 0.90, the plausible range). Those who took part in at least one round had about a 25% lower risk (RR 0.75). Now consider the NordICC randomized trial. Among people invited to have a colonoscopy, the 10-year incidence of colorectal cancer fell from 1.20% to 0.98% (RR 0.82; 95% CI 0.70 to 0.93).

Notes

Disputed. NordICC counts people by whether they were invited to have a colonoscopy, and colorectal cancer deaths were 0.28% versus 0.31% (RR 0.90, 95% CI 0.64 to 1.16), a difference still within the margin of error. This suggests the death-rate benefit of colonoscopy was overestimated in the past. The evidence for stool tests on death rate is actually firmer. The age to start varies by country guideline, between 45 and 50. If a relative has had this disease, start earlier.

Evidence grade
A : Specific numbers from meta-analyses, large cohorts or randomized trials; for law and policy, the statute or official text.
Sources
  1. Hewitson P 等 (2007). Screening for colorectal cancer using the faecal occult blood test, Hemoccult. Cochrane Database of Systematic Reviews. https://doi.org/10.1002/14651858.CD001216.pub2
  2. Bretthauer M 等 (2022). Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death. New England Journal of Medicine. https://doi.org/10.1056/NEJMoa2208375

Mentioned in

Translated from the Chinese original. Original book, section 1, tip 19. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer