Colorectal cancer in the family: Are earlier screening tests worth it?
In Germany, everyone is offered a colonoscopy to screen for colorectal cancer: men from the age of 50, and women from the age of 55. Many experts suggest that people should be offered a colonoscopy at an earlier age if they have close relatives who have (had) colorectal cancer. But it's not clear whether this 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 colorectal cancer, the answer depends on their specific situation.
In some families colorectal cancer develops in several people at a relatively young age. This happens most commonly in two inherited diseases: “hereditary nonpolyposis colorectal cancer” (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 is more common for someone's parents to develop colorectal cancer in older age, for instance. This could mean that their children have a higher risk of developing colorectal cancer too. In Germany, all men over the age of 50 and women over the age of 55 can have a colonoscopy to screen for colorectal cancer. Whether people with a sister, brother or parent with colorectal cancer should be entitled to this screening 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) summarized the currently available research results related to the following questions:
1. How high is someone's individual risk of developing colorectal cancer if a close blood relative developed this disease?
2. Is it worth doing screening tests sooner in people who are at greater risk?
3. When someone is asked whether their relatives have (had) colorectal cancer, how reliable is their answer?