Colon cancer screening practices and disclosure after receipt of positive or inconclusive genetic test results for hereditary nonpolyposis colorectal cancer

Cascade Testing for Hereditary Cancer Syndromes: Should We Move Toward Direct Relative Contact? A Systematic Review and Meta-Analysis

PURPOSE

Evidence-based guidelines recommend cascade genetic counseling and testing for hereditary cancer syndromes, providing relatives the opportunity for early detection and prevention of cancer. The current standard is for patients to contact and encourage relatives (patient-mediated contact) to undergo counseling and testing. Direct relative contact by the medical team or testing laboratory has shown promise but is complicated by privacy laws and lack of infrastructure. We sought to compare outcomes associated with patient-mediated and direct relative contact for hereditary cancer cascade genetic counseling and testing in the first meta-analysis on this topic.

MATERIALS AND METHODS

We conducted a systematic review and meta-analysis in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PROSPERO No.: CRD42020134276). We searched key electronic databases to identify studies evaluating hereditary cancer cascade testing. Eligible trials were subjected to meta-analysis.

RESULTS

Eighty-seven studies met inclusion criteria. Among relatives included in the meta-analysis, 48% (95% CI, 38 to 58) underwent cascade genetic counseling and 41% (95% CI, 34 to 48) cascade genetic testing. Compared with the patient-mediated approach, direct relative contact resulted in significantly higher uptake of genetic counseling for all relatives (63% [95% CI, 49 to 75] v 35% [95% CI, 24 to 48]) and genetic testing for first-degree relatives (62% [95% CI, 49 to 73] v 40% [95% CI, 32 to 48]). Methods of direct contact included telephone calls, letters, and e-mails; respective rates of genetic testing completion were 61% (95% CI, 51 to 70), 48% (95% CI, 37 to 59), and 48% (95% CI, 45 to 50).

CONCLUSION

Most relatives at risk for hereditary cancer do not undergo cascade genetic counseling and testing, forgoing potentially life-saving medical interventions. Compared with patient-mediated contact, direct relative contact increased rates of cascade genetic counseling and testing, arguing for a shift in the care delivery paradigm, to be confirmed by randomized controlled trials.

Patterns of family communication and preferred resources for sharing information among families with a Lynch syndrome diagnosis

OBJECTIVES

To explore patterns of communication among families with a Lynch syndrome diagnosis and understand what resources could facilitate family communication.

METHODS

127 probands (i.e., first person in family with identified mutation) and family members participated in semi-structured interviews about: how they learned about the Lynch syndrome diagnosis, with whom they shared genetic test results, confidence in sharing results with other family members, and helpfulness of educational resources.

RESULTS

Both probands and family members were most likely to share genetic test results with parents and siblings, and least likely to share results with aunts, uncles, and cousins. Most participants felt very confident sharing their test results with family members, but reported that certain topics such as cancer risk were challenging to convey. Probands reported the most helpful resources to be access to a specialty clinic or website, while family members described general printed materials as most helpful.

CONCLUSIONS

Families affected by Lynch syndrome may experience barriers to communication with more distant relatives, and may benefit from receiving specific resources (e.g., websites about Lynch syndrome, print materials) to facilitate family communication.

PRACTICE IMPLICATIONS

Providers could emphasize the need to share information with more distant family members and provide appropriate supportive resources.

Understanding the contribution of family history to colorectal cancer risk and its clinical implications: A state-of-the-science review

Persons with a family history (FH) of colorectal cancer (CRC) or adenomas that are not due to known hereditary syndromes have an increased risk for CRC. An understanding of these risks, screening recommendations, and screening behaviors can inform strategies for reducing the CRC burden in these families. A comprehensive review of the literature published within the past 10 years has been performed to assess what is known about cancer risk, screening guidelines, adherence and barriers to screening, and effective interventions in persons with an FH of CRC and to identify FH tools used to identify these individuals and inform care. Existing data show that having 1 affected first-degree relative (FDR) increases the CRC risk 2-fold, and the risk increases with multiple affected FDRs and a younger age at diagnosis. There is variability in screening recommendations across consensus guidelines. Screening adherence is <50% and is lower in persons under the age of 50 years. A provider's recommendation, multiple affected relatives, and family encouragement facilitate screening; insufficient collection of FH, low knowledge of guidelines, and poor family communication are important barriers. Effective interventions incorporate strategies for overcoming barriers, but these have not been broadly tested in clinical settings. Four strategies for reducing CRC in persons with familial risk are suggested: 1) improving the collection and utilization of the FH of cancer, 2) establishing a consensus for screening guidelines by FH, 3) enhancing provider-patient knowledge of guidelines and communication about CRC risk, and 4) encouraging survivors to promote screening within their families and partnering with existing screening programs to expand their reach to high-risk groups. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2633-2645. © 2016 American Cancer Society.

Concepts of 'personalization' in personalized medicine: implications for economic evaluation

CONTEXT

This study assesses if, and how, existing methods for economic evaluation are applicable to the evaluation of personalized medicine (PM) and, if not, where extension to methods may be required.

METHODS

A structured workshop was held with a predefined group of experts (n = 47), and was run using a modified nominal group technique. Workshop findings were recorded using extensive note taking, and summarized using thematic data analysis. The workshop was complemented by structured literature searches.

RESULTS

The key finding emerging from the workshop, using an economic perspective, was that two distinct, but linked, interpretations of the concept of PM exist (personalization by 'physiology' or 'preferences'). These interpretations involve specific challenges for the design and conduct of economic evaluations. Existing evaluative (extra-welfarist) frameworks were generally considered appropriate for evaluating PM. When 'personalization' is viewed as using physiological biomarkers, challenges include representing complex care pathways; representing spillover effects; meeting data requirements such as evidence on heterogeneity; and choosing appropriate time horizons for the value of further research in uncertainty analysis. When viewed as tailoring medicine to patient preferences, further work is needed regarding revealed preferences, e.g. treatment (non)adherence; stated preferences, e.g. risk interpretation and attitude; consideration of heterogeneity in preferences; and the appropriate framework (welfarism vs. extra-welfarism) to incorporate non-health benefits.

CONCLUSIONS

Ideally, economic evaluations should take account of both interpretations of PM and consider physiology and preferences. It is important for decision makers to be cognizant of the issues involved with the economic evaluation of PM to appropriately interpret the evidence and target future research funding.

Patient compliance based on genetic medicine: a literature review

For this literature review, medical literature data bases were searched for studies on patient compliance after genetic risk assessment. The review focused on conditions where secondary or tertiary preventive options exist, namely cancer syndromes (BRCA-related cancer, HNPCC/colon cancer), hemochromatosis, thrombophilia, smoking cessation, and obesity. As a counterpart, patient compliance was assessed regarding medication adherence and medical advice in some of the most epidemiologically important conditions (including high blood pressure, metabolic syndrome, and coronary heart disease) after receiving medical advice based on nongenetic risk information or a combination of genetic and nongenetic risk information. In the majority of studies based on genetic risk assessments, patients were confronted with predictive rather than diagnostic genetic profiles. Most of the studies started from a knowledge base around 10 years ago when DNA testing was at an early stage, limited in scope and specificity, and costly. The major result is that overall compliance of patients after receiving a high-risk estimate from genetic testing for a given condition is high. However, significant behavior change does not take place just because the analyte is "genetic." Many more factors play a role in the complex process of behavioral tuning. Without adequate counseling and guidance, patients may interpret risk estimates of predictive genetic testing with an increase in fear and anxiety.

Communicating cancer risk within an African context: experiences, disclosure patterns and uptake rates following genetic testing for Lynch syndrome

OBJECTIVE

Data pertaining to Lynch syndrome within a developing country are sparse. This study explored the emotional reaction to a mutation-positive test result among a group of individuals from South Africa. As genetic information is not only limited to the individual but extends to the biological family, communication patterns and uptake of testing among at-risk family members was also investigated.

METHODS

Eighty individuals participated in this qualitative interview study.

RESULTS

Eight emotional reactions were observed, of which two were of particular concern: (1) secrecy due to disbelief and (2) interpretation of a mutation-positive result as a cancer diagnosis. Disclosure rates of personal genetic test results were high to family members, but low to general healthcare providers. Disclosing the test result was not always followed by a discussion of implications of the genetic information or availability of predictive testing for at-risk family members. The uptake rate of predictive testing among the participants' siblings and children was 97% and 73.6%, respectively.

CONCLUSION

Awareness of concerning emotional reactions following the delivery of a genetic test result and insight into disclosure patterns, especially the information that is not communicated, will prove beneficial in improving the effectiveness of counselling and management in Lynch syndrome families.

PRACTICE IMPLICATIONS

Implementation of these findings into the PT programme will have a positive effect on the genetic counseling process.

Health behaviors in patients and families with hereditary colorectal cancer

It is estimated that 5 to 10% of all colorectal cancer (CRC) cases are attributed to a hereditary cause. The primary hereditary cancer syndromes that confer an increased risk for colorectal cancers are Lynch syndrome/hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP). Through genetic testing, health care providers can identify patients and families who carry gene mutations and subsequently are at a substantially greater risk for developing colorectal cancer than the general population. Genetic testing provides risk information not only about an individual patient, but also his or her biological relatives. A variety of risk-reduction behaviors (including screening, surgery, and health and lifestyle behaviors) have been examined in Lynch syndrome and FAP populations. The research indicates that screening behaviors are less than optimal, although the rates vary from study to study. Prophylactic colectomy is the primary course of treatment for individuals who test positive for a FAP mutation, but the results are inconclusive for cancer-unaffected Lynch syndrome mutation carriers. Although research suggests that the adoption of healthy lifestyles and behaviors (e.g., diet, physical activity, weight control, smoking cessation, limited alcohol consumption) could have a favorable impact on colon cancer burden, there is minimal data on how these behaviors may moderate cancer risk among those at risk of hereditary colon cancer. To date, we know very little about the actual health and lifestyle behaviors of those at risk of hereditary colon cancer. Genetic testing and counseling at risk individuals may resolve uncertainty about their personal and familial cancer risk and provide information to guide and personalize decisions about their future health care.

Screening and Health Behaviors among Persons Diagnosed with Familial Adenomatous Polyposis and Their Relatives

Familial Adenomatous Polyposis (FAP) is a rare autosomal dominantly inherited colorectal cancer syndrome. Individuals with FAP often undergo colectomy and are recommended to follow several surveillance protocols. Biological relatives of persons with FAP may also be at risk and thus should undergo genetic counseling. Screening adherence, genetic testing, and other health behaviors among individuals with FAP and their relatives are not well characterized. We conducted a cross-sectional self-report survey with individuals who have FAP (n = 35) and their biological relatives (n = 15). Respondents were recruited through a cancer center registry for inherited colon cancers. Most relatives had undergone colon cancer screening; 40% had undergone genetic testing. One fifth of respondents with FAP had not undergone an upper endoscopy, contrary to usual recommendations. Cigarette smoking rates were above average and were higher among FAP respondents. Use of vitamin supplements was fairly common, more so among those with FAP. Although most people had been screened, there are areas for improvement, notably for upper endoscopy among individuals with FAP and genetic testing among family members. Several other health-risk behaviors and health concerns other than FAP were identified. Further research into factors contributing to screening rates and other health behaviors in this high-risk population is warranted.

Development and validation of an instrument to measure the impact of genetic testing on self-concept in Lynch syndrome

A positive genetic test result may impact on a person's self-concept and affect quality of life. The purpose of the study was to develop a self-concept scale to measure such impact for individuals carrying mutations for a heritable colorectal cancer Lynch syndrome (LS). Two distinct phases were involved: Phase 1 generated specific colorectal self-concept candidate scale items from interviews with eight LS carriers and five genetic counselors, which were added to a previously developed self-concept scale for BRCA1/2 mutation carriers, Phase II had 115 LS carriers complete the candidate scale and a battery of validating measures. A 20-item scale was developed with two dimensions identified through factor analysis: stigma/vulnerability and bowel symptom-related anxiety. The scale showed excellent reliability (Cronbach's α = 0.93), good convergent validity by a high correlation with impact of event scale (r(102) = 0.55, p < 0.001) and Rosenberg self-esteem scale (r(108) = -0.59, p < 0.001), and a low correlation with the Fear questionnaire (r(108) = 0.37, p < 0.001). The scale's performance was stable across participant characteristics. This new scale for measuring self-concept has potential to be used as a clinical tool and as a measure for future studies.

Strategies to identify the Lynch syndrome among patients with colorectal cancer: a cost-effectiveness analysis

BACKGROUND

Testing has been advocated for all persons with newly diagnosed colorectal cancer to identify families with the Lynch syndrome, an autosomal dominant cancer-predisposition syndrome that is a paradigm for personalized medicine.

OBJECTIVE

To estimate the effectiveness and cost-effectiveness of strategies to identify the Lynch syndrome, with attention to sex, age at screening, and differential effects for probands and relatives.

DESIGN

Markov model that incorporated risk for colorectal, endometrial, and ovarian cancers.

DATA SOURCES

Published literature.

TARGET POPULATION

All persons with newly diagnosed colorectal cancer and their relatives.

TIME HORIZON

Lifetime.

PERSPECTIVE

Third-party payer.

INTERVENTION

Strategies based on clinical criteria, prediction algorithms, tumor testing, or up-front germline mutation testing, followed by tailored screening and risk-reducing surgery.

OUTCOME MEASURES

Life-years, cancer cases and deaths, costs, and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

The benefit of all strategies accrued primarily to relatives with a mutation associated with the Lynch syndrome, particularly women, whose life expectancy could increase by approximately 4 years with hysterectomy and salpingo-oophorectomy and adherence to colorectal cancer screening recommendations. At current rates of germline testing, screening, and prophylactic surgery, the strategies reduced deaths from colorectal cancer by 7% to 42% and deaths from endometrial and ovarian cancer by 1% to 6%. Among tumor-testing strategies, immunohistochemistry followed by BRAF mutation testing was preferred, with an incremental cost-effectiveness ratio of $36,200 per life-year gained.

RESULTS OF SENSITIVITY ANALYSIS

The number of relatives tested per proband was a critical determinant of both effectiveness and cost-effectiveness, with testing of 3 to 4 relatives required for most strategies to meet a threshold of $50,000 per life-year gained. Immunohistochemistry followed by BRAF mutation testing was preferred in 59% of iterations in probabilistic sensitivity analysis at a threshold of $100,000 per life-year gained. Screening for the Lynch syndrome with immunohistochemistry followed by BRAF mutation testing only up to age 70 years cost $44,000 per incremental life-year gained compared with screening only up to age 60 years, and screening without an upper age limit cost $88,700 per incremental life-year gained compared with screening only up to age 70 years.

LIMITATION

Other types of cancer, uncertain family pedigrees, and genetic variants of unknown significance were not considered.

CONCLUSION

Widespread colorectal tumor testing to identify families with the Lynch syndrome could yield substantial benefits at acceptable costs, particularly for women with a mutation associated with the Lynch syndrome who begin regular screening and have risk-reducing surgery. The cost-effectiveness of such testing depends on the participation rate among relatives at risk for the Lynch syndrome.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Strategies to identify the Lynch syndrome among patients with colorectal cancer: a cost-effectiveness analysis

BACKGROUND

Testing has been advocated for all persons with newly diagnosed colorectal cancer to identify families with the Lynch syndrome, an autosomal dominant cancer-predisposition syndrome that is a paradigm for personalized medicine.

OBJECTIVE

To estimate the effectiveness and cost-effectiveness of strategies to identify the Lynch syndrome, with attention to sex, age at screening, and differential effects for probands and relatives.

DESIGN

Markov model that incorporated risk for colorectal, endometrial, and ovarian cancers.

DATA SOURCES

Published literature.

TARGET POPULATION

All persons with newly diagnosed colorectal cancer and their relatives.

TIME HORIZON

Lifetime.

PERSPECTIVE

Third-party payer.

INTERVENTION

Strategies based on clinical criteria, prediction algorithms, tumor testing, or up-front germline mutation testing, followed by tailored screening and risk-reducing surgery.

OUTCOME MEASURES

Life-years, cancer cases and deaths, costs, and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

The benefit of all strategies accrued primarily to relatives with a mutation associated with the Lynch syndrome, particularly women, whose life expectancy could increase by approximately 4 years with hysterectomy and salpingo-oophorectomy and adherence to colorectal cancer screening recommendations. At current rates of germline testing, screening, and prophylactic surgery, the strategies reduced deaths from colorectal cancer by 7% to 42% and deaths from endometrial and ovarian cancer by 1% to 6%. Among tumor-testing strategies, immunohistochemistry followed by BRAF mutation testing was preferred, with an incremental cost-effectiveness ratio of $36,200 per life-year gained.

RESULTS OF SENSITIVITY ANALYSIS

The number of relatives tested per proband was a critical determinant of both effectiveness and cost-effectiveness, with testing of 3 to 4 relatives required for most strategies to meet a threshold of $50,000 per life-year gained. Immunohistochemistry followed by BRAF mutation testing was preferred in 59% of iterations in probabilistic sensitivity analysis at a threshold of $100,000 per life-year gained. Screening for the Lynch syndrome with immunohistochemistry followed by BRAF mutation testing only up to age 70 years cost $44,000 per incremental life-year gained compared with screening only up to age 60 years, and screening without an upper age limit cost $88,700 per incremental life-year gained compared with screening only up to age 70 years.

LIMITATION

Other types of cancer, uncertain family pedigrees, and genetic variants of unknown significance were not considered.

CONCLUSION

Widespread colorectal tumor testing to identify families with the Lynch syndrome could yield substantial benefits at acceptable costs, particularly for women with a mutation associated with the Lynch syndrome who begin regular screening and have risk-reducing surgery. The cost-effectiveness of such testing depends on the participation rate among relatives at risk for the Lynch syndrome.

PRIMARY FUNDING SOURCE

National Institutes of Health.

"The cancer bond": exploring the formation of cancer risk perception in families with Lynch syndrome

This study explores the social context of hereditary cancer risk perception in three families, an African-American family, a Mexican-American family, and a Caucasian family, each with Lynch Syndrome documented by a mismatch repair gene mutation. Communication network assessments measured family communication about cancer experiences and genetic testing information among a total of 26 participants. Participant narratives were evaluated to gain insight into how family cancer experiences and genetic testing information have shaped perceptions of cancer risk. Analysis of communication networks indicated that some families discussed cancer experiences to a greater extent than genetic testing information, and vice-versa. Interviews elucidated that sharing both types of health information led participants to conceptualize linkages among a strong family history of cancer, genetic testing information, and cancer prevention strategies. Understanding how different types of family communication influence the formation of perceived hereditary disease risk may enhance efforts to tailor genetic counseling services for families.

Communication, encouragement, and cancer screening in families with and without mutations for hereditary nonpolyposis colorectal cancer: a pilot study

PURPOSE

Known and suspected mutation carriers for hereditary nonpolyposis colorectal cancer are advised to have colonoscopies every 1 to 2 years to detect colorectal cancer. Little is known about colonoscopy completion in families suspected of having hereditary nonpolyposis colorectal cancer but without identified mutations.

METHODS

This study examined the effect of communication and encouragement on colonoscopy in families with and without known mutations. Twenty-three respondents from 11 families with indeterminate genetic test results were matched with 23 respondents from 11 families with mutation-positive results. Hierarchical modeling examined the effects of relational characteristics on time since last colonoscopy in index cases and their first-degree relatives.

RESULTS

Nearly one fifth of respondents were not screening appropriately. Time since last screening did not differ according to family mutation status. However, respondents who communicated about risk and received encouragement to screen from a greater proportion of named family members, and those who had a greater proportion of named family members involved in both communication and encouragement were significantly more likely to have a shorter time interval since last colonoscopy.

CONCLUSION

Identifying patterns of interaction within at-risk families, regardless of gene mutation status, may be one avenue for promoting screening adherence.