Centre for Research Ethics & Bioethics

Transcription

1 Managing incidental findings and research results in genomics Mats Hansson

2 Assigning rights to donors, Wolf et al. Gen Med 2012 Adapted from biobank context: 1. Clarify the criteria for evaluating findings and the roster of returnable findings 2. Analyze a particular finding in relation to this 3. Reidentify the individual patient/research participanyt 4. Recontact to offer the finding

3 If: 1. Findings are analytically valid (the test results reveal whether a particular genotype is present) 2. Associated with an established and substantial risk of a serious health condition 3. Are clinically actionable (treatment, prevention or for reproductive decisions)

4 Motivated by: 1. Respect for the patients/research participants autonomy 2. Maximizing benefit and minimizing harms 3. Helping patients/research participants to better welfare

5 Sounds appealing The idea originated in association with brain imaging research But, genomic studies and biobank research is different The presence of a given genotype must await evidence of both clinical validity and clinical utility in order to constitute meaningful information.

6 Genotype-Phenotype complexity There may be hundreds of variants related to the same phenotype Phenotype varies with regard to ethnic or environmental differences Sensitivity/specificity is variable and of vital interest for assessment of welfare for patients/research participants.

7 E.g. CYP2D6 and treatment response to tamoxifen For women > 35 years of age at increased risk of breast cancer five years of tamoxifen treatment yields a 49% reduction in invasive breast cancers But some do not respond du to suboptimal conversion of tamoxifen to the more potent and active metabolites carried out by CYP2D6

8 Gene tests for poor metabolizers available The tests differs with regard to performance sensitivity (the capacity of identifying a poor metabolizer) and specificity (the capacity to exclude those expressing the same phenotype but for other reasons)

9 Tamoxifen With low sensitivity a test may miss poor metabolizers that should not have tamoxifen With low specificity one may miss those whose phenotype is not truly related to CYP2D6, and therefore should have tamoxifen

10 So, analytic validity is not sufficient What counts is the phenotype, i.e. the welfare of the patient, and there may be hundreds of variants related to the same phenotype

11 A balanced compromise Biobanks and GWAS should: 1. Include a readiness to monitor the field and help in clarifying the criteria for evaluating incidental findings 2. Assess the preferences of donors and research subjects regarding incidental findings 3. Stimulate ethical analysis and discussion

12 A better understanding of preferences When asked, would you like to have information if there is: analytic validity, clinical significance and action ability? Who would say no? Need to find out the desired balance of benefits/risk Jennifer Viberg et al: Incidental findings: the time is not yet ripe for a policy for biobanks

13 A better understanding of preferences on risk The numeric sense of genetic risk does not always translate to one s understanding of risk information Research participants tend to understand genetic risk as a binary concept; you either are at risk, or you are not. With different thresholds Of significance for genetic counselling & communication

14 A better understanding of preferences on risk Viberg Johansson J, Segerdahl P, Höstery Ugander U, Hansson MG, Langenskiöld S, Making sense of genetic risk: a qualitative focus-group study of healthy participants in genomic research, Patient Education and counseling 2017, 09