Cascade screening for Tier 1 cancer genetic conditions is a significant public health intervention because it identifies untested relatives of individuals known to carry pathogenic variants associated with hereditary breast and ovarian cancer (HBOC) and Lynch syndrome (LS). The Swiss CASCADE is a family-based, open-ended cohort, including carriers of HBOC- and LS-associated pathogenic variants and their relatives. This paper describes rates of cascade screening in relatives from HBOC- and LS- harboring families, examines carriers’ preferences for communication of testing results, and describes theory-based predictors of intention to invite relatives to a cascade screening program. Information has been provided by 304 index cases and 115 relatives recruited from September 2017 to December 2021. On average, 10 relatives per index case were potentially eligible for cascade screening. Approximately 65% of respondents wanted to invite relatives to the cohort, and approximately 50% indicated a preference for patient-mediated communication of testing results, possibly with the assistance of digital technology. Intention to invite relatives was higher for first- compared to second- and third-degree relatives, but was not different between syndromes or based on relatives’ gender. The family environment and carrying pathogenic variants predicts intention to invite relatives. Information helps optimize delivery of tailored genetic services.

Cascade genetic testing of relatives from families with pathogenic variants associated with hereditary breast and ovarian cancer (HBOC) or Lynch syndrome (LS) has important implications for cancer prevention. We compared the characteristics of relatives from HBOC or LS families who did not have genetic testing (GT (−) group) with those who had genetic testing (GT (+) group), regardless of the outcome. Self-administered surveys collected cross-sectional data between September 2017 and December 2021 from relatives participating in the CASCADE cohort. We used multivariable logistic regression with LASSO variable selection. Among n = 115 relatives who completed the baseline survey, 38% (n = 44) were in the GT (−) group. Being male (OR: 2.79, 95% CI: 1.10–7.10) and without a previous cancer diagnosis (OR: 4.47, 95% CI: 1.03–19.42) increased the odds of being untested by almost three times. Individuals from families with fewer tested relatives had 29% higher odds of being untested (OR: 0.71, 95% CI: 0.55–0.92). Reasons for forgoing cascade testing were: lack of provider recommendation, lack of time and interest in testing, being afraid of discrimination, and high out-of-pocket costs. Multilevel interventions designed to increase awareness about clinical implications of HBOC and LS in males, referrals from non-specialists, and support for testing multiple family members could improve the uptake of cascade testing.

Background/Objectives: Individuals carrying hereditary breast and ovarian cancer (HBOC) and Lynch Syndrome (LS)-associated pathogenic variants have increased risk for cancers. The study examined the association between cancer diagnosis and health behaviors i.e., smoking, alcohol consumption, level of physical activity, and body mass index (BMI) among individuals with pathogenic variants associated with HBOC or LS. Methods: We used baseline and 18-month follow-up data from carriers of HBOC-or LS- associated variants from the Swiss CASCADE cohort. Generalized linear models with random effects were applied. Results: More than half (58%) of participants had at least one cancer diagnosis. Analyses of 856 observations from 518 individuals (HBOC:410, LS:108) showed that, after controlling for potential confounders, the proportion of current smokers was not significantly different between individuals diagnosed with cancer and never-diagnosed individuals (ß=4.5, p=0.18). Similarly, alcohol intake was not associated with cancer diagnosis (adjusted: ß= -0.2, p=0.51), although it was positively associated with time since genetic testing (ß=0.09, p< 0.01). Levels of physical activity were lower among individuals with cancer compared to never-diagnosed individuals (adjusted: ß= -0.5, p=0.002). There was no difference in BMI between individuals with cancer and individuals never diagnosed with cancer. Conclusions: Findings showed a decrease in levels of physical activity among carriers of HBOC- or LS-associated variants with a cancer diagnosis compared to never-diagnosed individuals, but no differences in smoking, alcohol consumption, or BMI. It is possible that near-term health behavior adjustments among individuals with HBOC- or LS-associated variants are associated with genetic testing results.

Background/Objectives: Individuals carrying pathogenic/likely pathogenic (P/LP) variants associated with hereditary breast and ovarian cancer (HBOC) and Lynch Syndrome (LS)- have increased risk for various types of cancer. The study compared health behaviors, i.e., smoking, alcohol consumption, level of physical activity, and body mass index (BMI) among affected and unaffected (never diagnosed) individuals with P/LP variants associated with HBOC or LS. Methods: We used baseline and 18-month follow-up data from individuals with HBOC- or LS-associated P/LP variants from the Swiss CASCADE study, an open-ended, prospective, family-based cohort. Generalized linear models with random effects were applied. Results: A total of 856 records from 518 participants (HBOC: 410; LS: 108) were analyzed. More than half (58%) of participants had at least one cancer diagnosis. After controlling for potential confounders, the proportion of current smokers was not significantly different between the two groups (ß = 3.5, p = 0.24). Alcohol intake was not associated with cancer diagnosis (adjusted: ß = −0.2, p = 0.57), although it was positively associated with time since genetic testing (ß = 0.11, p < 0.01). Levels of physical activity were lower among affected individuals compared to unaffected (adjusted: ß = −0.5, p = 0.03). There was no difference in BMI between the two groups. Conclusions: No significant differences in health behaviors, i.e., smoking, alcohol consumption, or BMI, were detected in individuals with P/LP variants associated with HBOC or LS unaffected by cancer and those with cancer diagnosis. Lower levels of physical activity in those with a cancer diagnosis could potentially be attributed to cancer treatment. Future studies should examine whether adjustments in health behavior are associated with the genetic diagnosis.