Colorectal cancer in the family: Are screening tests for people under the age of 55 worth it?

In Germany, everyone over the age of 55 is offered a colonoscopy for . Many experts suggest lowering this age for people who have close blood relatives who developed . But it is not yet clear whether earlier would actually have any advantages.
If a close blood relative has cancer, many people wonder whether they might be at higher risk of developing it themselves. With , the answer depends on the specific situation.
In some families develops in several people at a relatively young age. This happens most commonly in two inherited diseases: “hereditary nonpolyposis ” (HNPCC) and “familial adenomatous polyposis” (FAP). To help detect these diseases, it may be helpful to look for specific genes in family members who haven't had cancer. Families who are affected are offered special health care services. But these diseases are quite rare, and only a few families have them.
It's more common for someone's parents to develop in older age, for instance. This could mean that their children have a higher risk of developing too. In Germany, all men and women over the age of 55 can have a colonoscopy for . Whether people with a sibling or parent with should be entitled to this examination at a younger age is currently being debated.
In order to better assess the possible pros and cons of this idea, researchers at the Institute for Quality and Efficiency in Health Care (IQWiG, Germany) have summarized the currently available research results related to the following questions.
- How high is someone's individual risk of developing if a close blood relative developed this disease?
- Is it worth doing screening tests sooner in people who are at greater risk?
- When someone is asked whether their relatives have (had) , how reliable is the answer?