Oral Presentation NSW State Cancer Conference 2023

Mediators of changes in melanoma prevention and early detection behaviours in response to a genomic risk intervention in an Australian population sample (#44)

Amelia K Smit 1 2 , David Espinoza 3 , Serigne Lo 1 , Anne E Cust 1 2 , Managing Your Risk Study Group 4
  1. Melanoma Institute Australia, The University of Sydney, Sydney, NSW, Australia
  2. Daffodil Centre, The University of Sydney, The University Of Sydney, NSW, Australia
  3. NHMRC Clinical Trials Centre, The University of Sydney, Sydney, NSW, Australia
  4. Authorship group affilitation, Authorship group affiliation, Sydney, NSW, Australia

Background: A personal melanoma genomic risk intervention was trialled in the Melanoma Genomics Managing Your Risk Study, which demonstrated some improvements in melanoma prevention and early detection behaviours.

Purpose: We aimed to evaluate some hypothesised mediators on behaviour change outcomes.

Methods: Australians of European-ancestry without melanoma and aged 18-69 years were recruited via the Medicare database and randomised (n=1025). Questionnaires were administered at baseline, 1-month post-intervention (T1), and 12-months post-baseline (T2), measuring self-reported prevention and early detection behaviours and hypothesized mediators of behaviour change. The mediation analysis was conducted using the Barron and Kenny approach. Analysis was conducted in STATA/SEv14.2 with module PARAMED. Analyses were adjusted for traditional melanoma risk factors, state of residence, and age.

Results: Questionnaires were completed by 994 (97%) participants at T1 and 973 (95%) at T2. Perceived effectiveness of sun protection behaviours in reducing melanoma risk mediated the effect of receiving genomic risk information on sun protection habits (T1; mediated variable effect: 0.02, bootstrapped 95% confidence interval (CI): 0.00-0.04, p=0.03). Perceived risk of melanoma mediated the effect of receiving genomic risk information on reducing sunburn incidence (T2; 0.88, 95% CI: 0.80-0.94, p=0.001) and increasing sun protection habits (T1; 0.02, 95% CI: 0.01-0.05, p=0.01).

Conclusions: These findings identify mediators of sun-related behaviour change that could be used in targeted prevention, defining clinical trial eligibilities and early detection strategies to reduce melanoma risk in the Australian community.