The Psychological Impact of Genetic Testing for Hereditary Cancer

Abstract

Genetic testing shows great potential to deliver significant benefits in terms of health outcomes, and may raise a number of expectations about what may or may not be achieved. This thesis reports a series of studies relating to the psychological impact of the testing process. The first study compiled information about the experience of genetic testing from a group of patients at risk of Hereditary Non Polyposis Colorectal Cancer (HNPCC) using in-depth interviewing techniques. Thematic analysis was used to analyse the transcripts and issues common to the group fell under 6 main headings ranging from impact of test results to anxieties and expectations about testing and screening. A second prospective study attempted to obtain a preliminary assessment of how genetic testing impacted on the social construing of participants. Interviews using Repertory Grid technique were used with people 'at risk' of either familial colorectal cancer (HNPCC and FAP) or breast and ovarian cancer (HBOC) who were eligible for genetic testing. Interviews were conducted at pre-test, post-test and follow-up. Commonly occurring themes emerging across the groups were issues related to risk, relationships and interpersonal evaluation. Temporary shifts in construing were also observed. A problem that became apparent at an early stage of the second study concerned the impact on the participant's responses of procedural variations in the Repertory Grid presentation. A third study was therefore devised to assess this possibility directly. The effects of different kinds of examples used as an illustration for participants was investigated. A group of raters was asked to categorise constructs that had been elicited under two different conditions, using either descriptive examples or neutral examples. Descriptive examples elicited more personally revealing construct dimensions, highlighting the need for care in introducing repertory grid procedures to individuals. In conclusion there are three key findings from the studies. Firstly, that the consequences of genetic testing (regardless of whether the result is gene positive or gene negative) were potentially both beneficial and detrimental for those seeking testing and their families. Contrary to what may intuitively be expected, the experience of anxiety in light of a genetic test result was not exclusively the domain of those receiving a gene positive result. The second study provided insight into the impact of genetic testing over time and the findings suggest that such changes in construing as do occur are variable and relatively short-lived. Overall it would seem that obtaining a genetic test result was simply one piece of the puzzle; generally participants would assimilate this information without major life changes. The findings from the third study demonstrated the subtle ways in which people's responses in interviews may be unwittingly influenced by the interviewer. This was the first time this particular effect had been reported in the literature, which has subsequently been replicated with similar outcomes.