If a family is known to have FAP, the affected parent and at-risk children may be screened for a gene mutation with a genetic test. Children from families who refuse or cannot have genetic tests should start having sigmoidoscopies or colonoscopies at about 10 or 12 years old and every six to 12 months to look for the presence of polyps. Once numerous polyps start developing, surgery is planned. The good news about this disease is that the surgical options are very good. The bowel is put directly back together and no bag is necessary. People move their bowels normally.
The other inherited disorder is Hereditary Non-Polyposis Colorectal Cancer (HNPCC). In this syndrome cancers also occur early and develop from polyps. But here, there are not the hundreds of polyps seen in FAP. The disease presents at a later age, too. The standard recommendation is colonoscopy in at risk children of affected families beginning at age 25 and repeated every two years. Genetic testing may also be helpful here.
There are specific recommendations for children in families with high rates of colorectal cancer, but the specific syndrome must be known. It is very important for children from families like these to be seen by experts who have experience with these syndromes and in institutions where genetic counseling and testing services are available.
It is possible, although quite rare, for sporadic colon cancer to occur in young people outside of those affected by FAP or HNPCC.