Sarki, Mahesh . Understanding cascade testing and health behaviors in families with hereditary breast and ovarian cancer or Lynch syndrome-associated variants: the Swiss CASCADE cohort. 2024, Doctoral Thesis, University of Basel, Faculty of Medicine.
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Abstract
Summary
The main objective of this thesis was to gain an understanding of individuals and families at-risk of hereditary breast and ovarian cancer (HBOC) and Lynch Syndrome (LS) in Switzerland. The thesis provides descriptive data that can help improve cascade testing and support health behaviors change among members of families harboring HBOC- or LS-associated variants in Switzerland.
Chapter 1 introduces cancer, hereditary cancers and cancer burden and presents the global and Swiss prevalence of cancer. The chapter describes background information on cascade testing, predictors of cascade testing, significance of cascade testing, and health behaviors among individuals with HBOC- or LS-associated pathogenic variants, as well as containing the data sources for the thesis. This chapter also outlines rationale, research gaps, and aims of the thesis.
Chapter 2 presents the description and implementation of the Swiss CASCADE cohort for HBOC and LS families in Switzerland. The specific aims of the study are to describe rates of cascade testing in HBOC and LS families, to assess preferences for communication of genetic test results, and to identify predictors of intention to invite relatives to the cohort. Until December 2021, 304 index cases and 115 relatives had submitted baseline data. The study found that about 10 relatives per index case were potentially eligible for cascade testing, 62% had completed cascade testing, and nearly two-thirds (65%) wanted to invite at least one relative to the cohort. Most of the study participants (50%) preferred patient-mediated communication of genetic test results with the possible aid of digital tools. Intention to invite first-degree relatives was significantly higher compared to the wish to invite distant relatives (second-or third-degree relatives). The family environment and carrying a pathogenic variant significantly predicted the cohort participants’ decision to invite their relatives to the cohort.
Chapter 3 compares individual, family and healthcare system characteristics of relatives who did not have genetic testing with those who had genetic testing. The study also reports reasons for not having cascade testing. In total, 115 relatives submitted baseline data up through December 2021. Untested relatives had more frequent visits to non-specialists compared to tested relatives. Men (Odd Ratios (OR): 2.79, 95% Confidence Interval (CI): 1.10 – 7.10) and individuals with no prior cancer diagnosis (OR: 4.47, 95% CI: 1.03 – 19.42) had increased odds of being untested. Individuals with fewer tested relatives had 29% higher probability of being untested (OR: 0.71, 95% CI: 0.55 – 0.92). Lack of provider recommendation was one of the most common reasons reported for forgoing cascade testing. A few untested relatives also mentioned high out-of-pocket costs as a barrier for cascade testing.
Chapter 4 compares the health behaviors (i.e., smoking, alcohol intake, physical activity, and body mass index (BMI) of carriers of HBOC- or LS-associated pathogenic variants with and without a cancer diagnosis. By comparing these two groups, we aimed to assess whether a cancer diagnosis among carriers of HBOC- or LS-associated pathogenic variants triggered the adoption of a healthy behavior. We have included 768 observations from 486 individuals, who submitted baseline and follow-up data through February 2024. About six in ten respondents (59%) were diagnosed with a cancer and had a median time of 6.4 (3.0 – 12.5) years since their cancer diagnosis. Carriers of pathogenic variants with a cancer diagnosis had a lower physical activity (ß= -0.6, p = 0.004) than carriers of pathogenic variants without a cancer diagnosis, while we found no difference in smoking, alcohol, and BMI between the two groups.
Chapter 5 outlines the main findings of the thesis and presents a discussion for the possible implications of the results to HBOC and LS families in Switzerland. We recommend interventions at individual, family, and healthcare system levels to improve cascade testing and support health behaviors change among families with HBOC- or LS-associated pathogenic variants. This study provides insights into male-targeted interventions mainly for HBOC syndrome and explains some possible reasons for the reduced participation and cascade testing among men. Furthermore, it highlights the role of family and its significance in promoting cascade testing among at-risk relatives. Digital tools such as the Family Gene Toolkit and chatbots may potentially help improve the rates of cascade testing. Moreover, the result of this study summarizes the importance of empowering non-specialist healthcare providers in early evaluation of genetic risk in families and referring at-risk individuals to specialists for appropriate care. Possible interventions for empowering non-specialists to promote genetic risk assessments have also been suggested. In addition, the chapter discusses the observation that carriers of disease-causing variants may adopt healthy behaviors after learning about their mutation status, potentially motivated by wishing to prevent cancer occurrence, reducing the fear of cancer recurrence, and improving their quality of life. The current existing nutrition and physical activity guidelines do not cover carriers of pathogenic variants, particularly carriers of pathogenic variants without a cancer diagnosis. Establishing health behavior guidelines for carriers of HBOC- or LS-associated pathogenic variants may support and sustain health behaviors change. Finally, this chapter also presents personal reflections on the implications of the thesis results, as well as strengths and limitations of the thesis.
Chapter 6 summarizes the thesis with concluding remarks about improving cascade testing and supporting health behaviors change among individuals with HBOC- or LS-associated pathogenic variants in Switzerland.
The main objective of this thesis was to gain an understanding of individuals and families at-risk of hereditary breast and ovarian cancer (HBOC) and Lynch Syndrome (LS) in Switzerland. The thesis provides descriptive data that can help improve cascade testing and support health behaviors change among members of families harboring HBOC- or LS-associated variants in Switzerland.
Chapter 1 introduces cancer, hereditary cancers and cancer burden and presents the global and Swiss prevalence of cancer. The chapter describes background information on cascade testing, predictors of cascade testing, significance of cascade testing, and health behaviors among individuals with HBOC- or LS-associated pathogenic variants, as well as containing the data sources for the thesis. This chapter also outlines rationale, research gaps, and aims of the thesis.
Chapter 2 presents the description and implementation of the Swiss CASCADE cohort for HBOC and LS families in Switzerland. The specific aims of the study are to describe rates of cascade testing in HBOC and LS families, to assess preferences for communication of genetic test results, and to identify predictors of intention to invite relatives to the cohort. Until December 2021, 304 index cases and 115 relatives had submitted baseline data. The study found that about 10 relatives per index case were potentially eligible for cascade testing, 62% had completed cascade testing, and nearly two-thirds (65%) wanted to invite at least one relative to the cohort. Most of the study participants (50%) preferred patient-mediated communication of genetic test results with the possible aid of digital tools. Intention to invite first-degree relatives was significantly higher compared to the wish to invite distant relatives (second-or third-degree relatives). The family environment and carrying a pathogenic variant significantly predicted the cohort participants’ decision to invite their relatives to the cohort.
Chapter 3 compares individual, family and healthcare system characteristics of relatives who did not have genetic testing with those who had genetic testing. The study also reports reasons for not having cascade testing. In total, 115 relatives submitted baseline data up through December 2021. Untested relatives had more frequent visits to non-specialists compared to tested relatives. Men (Odd Ratios (OR): 2.79, 95% Confidence Interval (CI): 1.10 – 7.10) and individuals with no prior cancer diagnosis (OR: 4.47, 95% CI: 1.03 – 19.42) had increased odds of being untested. Individuals with fewer tested relatives had 29% higher probability of being untested (OR: 0.71, 95% CI: 0.55 – 0.92). Lack of provider recommendation was one of the most common reasons reported for forgoing cascade testing. A few untested relatives also mentioned high out-of-pocket costs as a barrier for cascade testing.
Chapter 4 compares the health behaviors (i.e., smoking, alcohol intake, physical activity, and body mass index (BMI) of carriers of HBOC- or LS-associated pathogenic variants with and without a cancer diagnosis. By comparing these two groups, we aimed to assess whether a cancer diagnosis among carriers of HBOC- or LS-associated pathogenic variants triggered the adoption of a healthy behavior. We have included 768 observations from 486 individuals, who submitted baseline and follow-up data through February 2024. About six in ten respondents (59%) were diagnosed with a cancer and had a median time of 6.4 (3.0 – 12.5) years since their cancer diagnosis. Carriers of pathogenic variants with a cancer diagnosis had a lower physical activity (ß= -0.6, p = 0.004) than carriers of pathogenic variants without a cancer diagnosis, while we found no difference in smoking, alcohol, and BMI between the two groups.
Chapter 5 outlines the main findings of the thesis and presents a discussion for the possible implications of the results to HBOC and LS families in Switzerland. We recommend interventions at individual, family, and healthcare system levels to improve cascade testing and support health behaviors change among families with HBOC- or LS-associated pathogenic variants. This study provides insights into male-targeted interventions mainly for HBOC syndrome and explains some possible reasons for the reduced participation and cascade testing among men. Furthermore, it highlights the role of family and its significance in promoting cascade testing among at-risk relatives. Digital tools such as the Family Gene Toolkit and chatbots may potentially help improve the rates of cascade testing. Moreover, the result of this study summarizes the importance of empowering non-specialist healthcare providers in early evaluation of genetic risk in families and referring at-risk individuals to specialists for appropriate care. Possible interventions for empowering non-specialists to promote genetic risk assessments have also been suggested. In addition, the chapter discusses the observation that carriers of disease-causing variants may adopt healthy behaviors after learning about their mutation status, potentially motivated by wishing to prevent cancer occurrence, reducing the fear of cancer recurrence, and improving their quality of life. The current existing nutrition and physical activity guidelines do not cover carriers of pathogenic variants, particularly carriers of pathogenic variants without a cancer diagnosis. Establishing health behavior guidelines for carriers of HBOC- or LS-associated pathogenic variants may support and sustain health behaviors change. Finally, this chapter also presents personal reflections on the implications of the thesis results, as well as strengths and limitations of the thesis.
Chapter 6 summarizes the thesis with concluding remarks about improving cascade testing and supporting health behaviors change among individuals with HBOC- or LS-associated pathogenic variants in Switzerland.
Advisors: | Katapodi, Maria C |
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Committee Members: | Fink, Günther and Frey, Melissa K. |
Faculties and Departments: | 03 Faculty of Medicine > Departement Public Health > Ehemalige Einheiten Public Health > Pflegewissenschaft (Katapodi) |
UniBasel Contributors: | Fink, Günther |
Item Type: | Thesis |
Thesis Subtype: | Doctoral Thesis |
Thesis no: | 15600 |
Thesis status: | Complete |
Number of Pages: | X, 130 |
Language: | English |
Identification Number: |
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edoc DOI: | |
Last Modified: | 04 Feb 2025 05:30 |
Deposited On: | 03 Feb 2025 08:38 |
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