Table 16. Summary of Prospective Studies Evaluating Participation in Genetic Counseling and Testing for Hereditary Colorectal Cancer (CRC)a,b,c continued...
Results of qualitative interview data from 28 U.S. parents diagnosed with FAP showed that 61% favored genetic testing of APC mutations in their at-risk children (aged 10-17 years); 71% believed that their children should receive their test results. The primary reasons why parents chose to test their children included early detection and management, reduction in parental anxiety and uncertainty, and help with decision making regarding surveillance. Reasons provided for not testing focused on discrimination concerns and cost.
Clinical observations suggest that children who have family members affected with FAP are very aware of the possibility of risk-reducing surgery, and focus on the test result as the factor that determines the need for such surgery. It is important to consider the timing of disclosure of genetic test results to children in regard to their age, developmental issues, and psychological concerns about FAP. Children who carry an FAP mutation have expressed concern regarding how they will be perceived by peers and might benefit from assistance in formulating an explanation for others that preserves self-esteem.
Interest in the Use of Assisted Reproductive Technology (ART)
The possibility of transmitting a mutation to a child may pose a concern to families affected by hereditary CRC syndromes to the extent that some carriers may avoid childbearing. These concerns also may prompt individuals to consider using prenatal diagnosis (PND) methods to help reduce the risk of transmission. PND is an encompassing term used to refer to any medical procedure conducted to assess the presence of a genetic disorder in a fetus. Methods include amniocentesis and chorionic villous sampling .[20,21] Both procedures carry a small risk of miscarriage.[20,22] Moreover, discovering the fetus is a carrier of a cancer susceptibility mutation may impose a difficult decision for couples regarding pregnancy continuation or termination and may require additional professional consultation and support.
An alternative to these tests is preimplantation genetic diagnosis (PGD), a procedure used to test fertilized embryos for genetic disorders before uterine implantation.[23,24] Using the information obtained from the genetic testing, potential parents can decide whether or not to implant. PGD can be used to detect mutations in hereditary cancer predisposing genes, including APC.[18,25,26]
From the limited studies published to date, there appears to be interest in the use of ART for FAP, LS, and PJS.[18,25,27,28] However, actual uptake rates have not been reported.