Predictors of enrollment into a familial cancer registry by individuals at high risk for BRCA1/2.

Background: Registries of individuals at risk for hereditary cancer syndromes are an invaluable resource for cancer research, yet little is known about the predictors of enrollment in hereditary cancer registries. We sought to identify the factors that characterize individuals who enroll versus those who decline participation in a Familial Cancer Registry (FCR). We also sought to identify the factors associated with provision of a blood sample to the FCR.

Methods: Participants (n = 549) had a 10% or greater prior probability of having a BRCA1/2 mutation or were members of a family with a known BRCA1/2 mutation.

Results: Of 549 participants, 81.1% (n = 445) enrolled in the FCR and 18.9% (n = 104) declined. Independent significant predictors of FCR participation included: lower anxiety (odds ratio(0.5 SD), 0.83; 95% confidence interval, 0.73-0.95) and being unaffected with breast or ovarian cancer (odds ratio, 0.52; 95% confidence interval, 0.39-0.67). Of the 445 FCR participants, 80.4% provided a blood sample whereas 19.6% declined, with blood sample provision predicted by being employed full time (odds ratio, 1.68; 95% confidence interval, 1.31-2.16).

Conclusion: These findings have implications for the generalizability of results from research using hereditary cancer registry samples. Individuals who are affected with breast/ovarian cancer and have more anxiety are less likely to enroll in a hereditary cancer registry. Clinically, these results indicate that cancer registry enrollment strategies could benefit from the use of tailored approaches to increase the enrollment of individuals that are less likely to participate.