Predictors for participation in DNA self-sampling of childhood cancer survivors in Switzerland

Abstract

Research on germline genetic variants relies on a sufficient number of eligible participants which is difficult to achieve for rare diseases such as childhood cancer. With self-collection kits using saliva or buccal swabs, participants can contribute genetic samples conveniently from their home. We identified determinants of participation in DNA self-collection in this cross-sectional study. We invited 928 childhood cancer survivors in Switzerland with a median age of 26.5 years (interquartile range 18.8-36.5), of which 463 (50%) participated. Foreign nationality (odds ratio [OR] 0.5, 95%-confidence interval [CI] 0.4-0.7), survivors aged 30-39 years at study versus other age groups (OR 0.5, CI 0.4-0.8), and those with a known cancer predisposition syndrome (OR 0.5, CI 0.3-1.0) participated less. Survivors with a second primary neoplasm (OR 1.9, CI 1.0-3.8) or those living in a French or Italian speaking region (OR 1.3, 1.0-1.8) tended to participate more. We showed that half of survivors participate in germline DNA self-sampling relying completely on mailing of sample kits. Foreign nationality, age 30-39 years, and cancer predisposition syndromes were associated with less participation. More targeted recruitment strategies may be advocated for these subgroups. To increase participation in DNA self-sampling, understanding and perceptions of survivors need to be better understood.