Psychosocial research in the context of cancer genetic testing helps to define psychological outcomes, interpersonal and familial effects, and cultural and community responses. It also identifies behavioral factors that encourage or impede screening and other health behaviors. It can enhance decision-making about risk-reduction interventions, evaluate psychosocial interventions to reduce distress and/or other negative sequelae related to risk notification and genetic testing, provide data to help resolve ethical concerns, and predict the interest in testing of various groups.
Research in these areas is limited by few randomized controlled trials, and many reports are based on uncontrolled studies of selected high-risk populations. Research is likely to expand considerably with access to larger populations of at-risk individuals.
There have been a number of descriptions of cancer genetics programs that provide genetic susceptibility testing.[1,2,3,4,5,6,7,8,9] The development of such programs was encouraged by federal funding of multidisciplinary research programs that offered intensive genetic counseling for hereditary cancer syndromes, psychological assessment and back-up, and physician involvement.
Uptake of Genetic Counseling and Genetic Testing
Degree of uptake of genetic counseling and genetic testing
Comparison of uptake rates across studies is challenging because of differences in methodologies, including the sampling strategy used, the recruitment setting, and testing through a research protocol with high-risk cohorts or kindreds. In a systematic review of 40 studies conducted before 2002 that had assessed genetic testing utilization, uptake rates varied widely and ranged from 25% to 96%, with an average uptake rate of 59%. Results of multivariate analysis found that BRCA1/BRCA2 genetic testing uptake was associated with having a personal or family history of breast or ovarian cancer, and with methodological features of the studies, including sampling strategies, recruitment settings, and how studies defined actual uptake versus the intention to have testing.
Other factors have been positively correlated with uptake of BRCA1/BRCA2 genetic testing, although these findings are not consistent across all studies. Psychological factors that have been positively correlated with testing uptake include greater cancer-specific distress and greater perceived risk of developing breast or ovarian cancer. Having more cancer-affected relatives also has been correlated with greater testing uptake.
These data are informative for research cohorts, but they are not relevant to clinical practice. Few studies have examined the rates of uptake and utilization of genetic testing in the current clinical environment.
Table 10 summarizes the uptake of genetic testing in clinical and research cohorts in the United States.