Mikhail, Dalia S.

Abstract Introduction: Family reinforcement (praise, reminders) may influence health behaviors and affect cancer knowledge, including risk factors. There has been insufficient research on the influence of familial factors in cancer prevention, especially for individuals with a family history of pancreatic cancer (PC). Objectives were to assess: 1) associations between family history of PC and familial reinforcement of cancer prevention with PC knowledge, and 2) interaction between family history of PC and familial reinforcement of cancer prevention on PC knowledge. Methods: A sample of 778 unaffected relatives with ≥1 affected first (FDR) or second degree relatives (SDR) were ascertained from Mayo Clinic’s Biospecimen Resource for Pancreas Research, a familial PC registry, along with 685 primary care controls. Participants with a personal history of cancer were excluded with the exception of non-melanoma skin cancer. Participants completed health/behavior questionnaires (June 2008 to June 2018). Items were summed to create factor scores for familial reinforcement of cancer prevention and PC knowledge. PC family history was categorized by number of relatives with PC: 1) none, 2) 1 FDR and/or ≥1 SDR, and 3) ≥2 FDRs. We employed linear models utilizing generalized estimating equations to assess the association between PC family history and familial reinforcement with PC knowledge, and the interaction based on PC family history, adjusting for age, sex, and education, and accounting for familial relatedness. Estimates of the linear coefficient β and 95% confidence intervals (CI) are reported, and p-values < 0.05 were considered significant. Analyses were conducted using SAS 9.4 (SAS Institute, Cary, NC). Results: There was a significant association between PC family history and PC knowledge such that those with 1 FDR and/or ≥1 SDR (β=3.0; 95% CI: 2.5-3.4; p<0.0001) or ≥2 FDRs (β=4.4; 95% CI: 3.7-5.0; p<0.0001) with PC had increased PC knowledge after adjusting for age, sex, and education. There was a significant association between familial reinforcement and PC knowledge such that individuals with increased familial reinforcement (β=0.1; 95% CI: 0.03-0.12; p=0.0026) had higher PC knowledge after adjusting for pertinent covariates. The interaction between PC family history and familial reinforcement was significant such that increased familial reinforcement was associated with higher PC knowledge in individuals with ≥2 FDRs with PC compared to controls (β=0.2; 95% CI: 0.09-0.34; p=0.001); however, this relationship was not significant in individuals with 1 FDR and/or ≥1 SDR. Conclusions: Individuals with a stronger family history of PC may benefit from increased familial reinforcement of cancer prevention to enhance knowledge about PC. Further efforts should be targeted toward incorporating the family in cancer care to raise familial awareness about PC. Citation Format: Maria Stevens, Dalia Mikhail, Amanda Toledo Hernandez, Sarah Fagan, Kari Chaffee, Gloria M. Petersen. Familial reinforcement and family history interact to influence knowledge about pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2426.