Intention to Inform Relatives, Rates of Cascade Testing, and Preference for Patient-Mediated Communication in Families Concerned with Hereditary Breast and Ovarian Cancer and Lynch Syndrome: The Swiss CASCADE Cohort

Abstract

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.

The Communication Chain of Genetic Risk: Analyses of Narrative Data Exploring Proband–Provider and Proband–Family Communication in Hereditary Breast and Ovarian Cancer

“…However, our own data, and data from an independent Swiss-based sample [ 38 ], suggest that although probands embrace some forms of provider-mediated communication, they do not want to be excluded from this process. Survey data collected as part of the CASCADE study indicate that only one in three or fewer individuals with HBOC- or LS-associated pathogenic variants endorsed provider-mediated communication [ 31 ]. Other studies have also shown a preference for proband-mediated family communication [ 11 , 22 , 39 ].…”

“…This descriptive, grounded theory-based analysis used individual interviews and focus groups to collect narrative data from a sample of women identified as carriers of HBOC-associated pathogenic variants. Individuals were recruited from the CASCADE study, an open-ended cohort designed to elicit factors that enhance cascade genetic screening for HBOC and Lynch syndrome in Switzerland (NCT03124212) [ 31 ]. Confirmed carriers of pathogenic variants who were 18 years or older were recruited from university centers, cantonal hospitals, and private praxis in three linguistic regions of Switzerland.…”

Relatives from Hereditary Breast and Ovarian Cancer and Lynch Syndrome Families Forgoing Genetic Testing: Findings from the Swiss CASCADE Cohort

“…Basic health insurance in Switzerland does not cover the cost of cascade testing for SDR and TDR [ 56 ]. Given that approximately half of the non-invited relatives in the CASCADE cohort are SDR and TDR [ 35 ], out-of-pocket costs (about CHF 400 or USD 410) could be a barrier for the approximately 27% of untested SDR and TDR in the study. Additional reasons for foregoing testing, such as not interested, busy, and valuing other life events more than genetic testing, have been reported also by others [ 16 , 21 , 27 , 29 ].…”

“…Excluded are individuals diagnosed with variants of unknown significance, non-blood relatives, and critically ill patients unable to provide written consent. Details about the cohort have been previously published [ 35 ]. For this analysis, we focused on comparing relatives who did not have genetic testing (GT (−) group) with those who had testing (GT (+) group).…”

Privacy and utility of genetic testing in families with hereditary cancer syndromes living in three countries: the international cascade genetic screening experience

“…The cohort was initiated in Switzerland, which had acquired most data at the time of the workshop. The development of the Swiss CASCADE and rates of genetic testing among relatives have been presented ( Sarki et al, 2022a ; Sarki et al, 2022b ). In short, the Swiss CASCADE had consented 365 index cases (276 HBOC and 89 LS) and 158 relatives (140 HBOC and 18 LS).…”