Best of the Best Oral Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2020

The impact of personal melanoma genomic risk information on skin cancer prevention behaviours and psychosocial outcomes - a randomised controlled trial (#23)

Anne E Cust 1 , Amelia Smit 1 , on behalf of the Managing Your Risk Study Group 2
  1. Sydney School of Public Health & Melanoma Institute Australia, The University of Sydney, Sydney, NSW, Australia
  2. Multiple affiliations, Australia and overseas

Aims: To evaluate the impact of personal melanoma genomic risk information on sun-related behaviors, ultraviolet radiation (UV) exposure and psychosocial outcomes.

Methods: We conducted a parallel group, open, randomised controlled trial. Participants aged 18-69 years, with no melanoma and European ancestry, were recruited across Australia via Medicare database mailout (3% consent). Over springs/summers Oct-17 to Feb-19, 1,025 participants were randomised to the intervention (saliva DNA sample, personalised booklet with melanoma genomic risk based on a 40-variant polygenic score, telephone-based genetic counselling, educational booklet; n=513) or control arm (educational booklet only; n=512). UV dosimeters (worn on the wrist over clothing) and questionnaires were administered at baseline, 1-month post-intervention, and at 12-months. The primary outcome was objectively measured UV exposure at 12-months. Analyses were intention-to-treat comparing intervention vs control arms, stratified by traditional (phenotypic) risk group (high n=505; low n=520) and adjusted for baseline values and randomised stratification factors.

Results: At 12-months, 948 (92%) participants completed dosimetry and 973 (95%) the questionnaire. Compared to controls, the intervention had no effect on either dosimetry-measured or self-reported sun exposure. The intervention significantly reduced sunburn incidence at 12-months, overall and for the high traditional risk group. The intervention increased skin examinations among women but not men. Sun protection behaviours, particularly sunscreen use and hat wear, were significantly increased at 1-month but this was attenuated at 12-months; the effects were stronger for the 45-69y age-group and higher socio-economic group. There was no impact on general psychological distress overall, but skin cancer-related worry was lower at 12-months and there were some differences by subgroup.

Conclusions: Personal melanoma genomic risk information did not influence patterns of personal sun exposure, but did impact sun protection, sunburn and skin examination behaviours. There was no evidence of harm, but the impact on behaviours and psycho-social outcomes differed for some population subgroups.