When respondents were asked about possible reactions if genetic testing showed that they were at high risk of CRC, the most common concerns included the lack of availability of preventive options, increased anxiety, and worry about cancer risks in family members, especially children. Virtually no concern was expressed regarding the potential impact of such information on insurance or employment discrimination. This finding contrasts with findings in some other studies of individuals who have gone through genetic counseling before deciding about testing. Additionally, individuals with health insurance coverage were most likely to be willing to share test results with others, primarily their physicians.
Participants in these studies were drawn from the general population and were not selected for known CRC risk factors; their interest in genetic testing was based on answers to largely hypothetical questions. Some findings indicate that interest in genetic testing may be high in the general population; however, the apparent interest may be due in part to a lack of awareness about the risks and limitations of testing or the view that genetic testing is similar to other more routine medical tests. Although these studies may help assess interest in genetic testing in the general population, it is possible that they overestimate the actual demand for such services.[5,6]
Interest in genetic counseling and testing among CRC patients and their close relatives
Studies of CRC patients and their unaffected relatives showed varying levels of interest in or intention to undergo hereditary CRC genetic testing (see Tables 13 and 14). Participants in these studies were recruited through tumor registries or familial colon cancer registries,[7,8,9,10] oncology treatment centers,[11,12,13,14] and the community.[9,12,13,14] Study outcomes were reported as either testing interest or testing intention. Participants were not necessarily selected based on features that are characteristic of a hereditary CRC syndrome. Thus, when asking about intention or interest in genetic testing, most studies referred to testing in a general manner (e.g., testing for a hereditary colon cancer gene) rather than asking about testing for specific syndromes such as LS (also called hereditary nonpolyposis colorectal cancer [HNPCC]) or FAP. Some factors that were not consistently addressed in all studies (e.g., cost, test accuracy, or assuming that other relatives were gene mutation carriers) may account for some of the variability in findings regarding testing interest or intention.