Clinical usefulness of genetic testing for drug toxicity in cancer care: decision-makers’ framing, knowledge and perceptions

Abstract

To explore the clinical uptake of pharmacogenetic/pharmacogenomic toxicity testing to reduce adverse drug reaction incidences, this paper analyzes data collected through semi-structured face-to-face interviews with clinicians and/or clinician-scientists, primarily in the context of cancer treatment in multi-ethnic California (US), Vancouver (Canada) and Singapore. Recurrent themes in the data include the following: first, the scientific evidence for drug-gene interactions is perceived to be generally weak. Second, the primacy of medical treatment’s efficacy over toxicity is the predominant frame through which clinicians consider testing. Third, physicians tailor their decisions according to each patient’s tolerance levels for toxicity. Fourth, racially and ethnically based toxicity risk estimates are a factor shaping the clinical uptake of genetic tests, but they are controversial. These factors contribute to the low clinical uptake of toxicity testing for predictive purposes. We argue that the decision-makers’ framing and perception are additional features to be considered in Hedgecoe’s (2008) “clinical usefulness” framework.