Gene-Environmental Risk Assessment and CRC Screening


Principal Investigator: David S Weinberg
Abstract: DESCRIPTION (provided by applicant): Genetic testing for cancer susceptibility is currently offered only to subgroups of the population at high risk for single gene disorders. However, for most common cancers, susceptibility results from the variable contributions of many genes usually influenced by environmental factors. Assessing genes (and their environmental modifiers) with moderate predictive power for disease is expected to become an integral part of healthcare. At-risk persons might be identified before disease onset and risk reduction practices recommended earlier. Little is known about the effect of providing this information to average risk persons on their adoption of risk reduction practices or its psychological impact. Colorectal cancer (CRC) prevention is a promising area to study this emerging role for genetic testing. Individualized gene and environmental risk (GERA) feedback represents a potentially innovative method to increase CRC screening compliance. In the proposed study, average risk individuals (n=1950) who are not adherent to screening will be randomly assigned to usual care (DC) or to GERA feedback based on an assessment of the participant's polymorphic version of the MTHFR gene and serum folate level (environment). Epidemiological data support links between MTHFR, folate and CRC. Participants randomized to GERA will be offered MTHFR genotyping and folate measurement. A trained nurse will discuss testing results (elevated v. average risk) and review their significance relative to CRC. The study has 4 specific aims:(1) to determine the impact of GERA v. DC on CRC screening rates;(2) to determine the impact of GERA v. DC on psychological distress;(3) to determine the impact of GERA v. DC on CRC knowledge and attitudes (e.g. perceived risk etc);and (4) to identify factors that moderate the impact of GERA feedback on CRC screening utilization. Psychosocial data will be collected at baseline, at the time of results disclosure, and 1 week and 6 months after the study office visit. This project will provide information about the effect of GERA on CRC screening participation. It may also be relevant information about how genetic testing for common healthcare conditions will ultimately be integrated into standard clinical practice.
Funding Period: 2006-08-15 - 2013-07-31
more information: NIH RePORT