Genetic testing in familial melanoma: uptake and implications

Cascade genetic testing for hereditary cancer syndromes: a review of barriers and breakthroughs

Germline genetic sequencing is now at the forefront of cancer treatment and preventative medicine. Cascade genetic testing, or the testing of at-risk relatives, is extremely promising as it offers genetic testing and potentially life-saving risk-reduction strategies to a population exponentially enriched for the risk of carrying a cancer-associated pathogenic variant. However, many relatives do not complete cascade testing due to barriers that span individual, relationship, healthcare community, and societal/policy domains. We have reviewed the published research on cascade testing. Our aim is to evaluate barriers to cascade genetic testing for hereditary cancer syndromes and explore strategies to mitigate these barriers, with the goal of promoting increased uptake of cascade genetic testing.

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.

Adolescent and parent perspectives on genomic sequencing to inform cancer care

Next-generation sequencing offers opportunities for targeted cancer therapies and may identify pathogenic germline variants. Adolescents' perception of testing is not well understood. We surveyed 16 adolescents and 59 parents regarding motivations, attitudes, and knowledge related to paired tumor/germline sequencing. Participants generally had a good objective understanding of germline genetics and cancer risk, with parents scoring higher than adolescents. Nearly all participants were motivated by a desire to help other patients and to treat their child/themselves. Most adolescents reported involvement in the decision to enroll in the study. Study findings suggest important similarities and differences between parent and adolescent views.

The role of emotional sensitivity to probability in the decision to choose genetic testing

While the availability of genetic testing is rapidly increasing, many opt out of testing. The decision to test or not is emotionally charged, and both clinical research and theoretical work in psychology show that in emotional decisions, people often struggle to interpret and utilize risk information. Clinical research on genetic testing uptake also shows that feeling overwhelmed by numeric information may be a deterrent to testing. However, recent psychological research indicates that some portion of the population has greater emotional sensitivity to probability, (i.e., the extent to which emotional reactions to risk depend on probabilities) than others. We hypothesize that participants high in emotional sensitivity to probability will be more interested in genetic testing as an opportunity to seek greater precision in risk estimates and that this relationship is moderated by the testing context itself. In an online survey of a nationally representative sample (not recruited as patients), participants were presented with a hypothetical scenario describing a suspected diagnosis with an option for genetic testing. The scenario experimentally varied the pre-test probability estimate of the diagnosis (low or high) and whether the test results would result in certainty (ruling in or ruling out the diagnosis), or reduced uncertainty (providing a more precise individual risk estimate). Results indicated that emotional sensitivity to probability was a strong predictor of intention to test, particularly when the test allowed participants to rule out a diagnosis, reducing an already low probability to zero. These results highlight the way patients' individual characteristics interact with the testing context to guide decision-making and provide important insight into the way patients integrate risk probability information into intensely emotional decisions.

A Systematic Review on the Impact of Genetic Testing for Familial Melanoma II: Psychosocial Outcomes and Attitudes

BACKGROUND

Although genetic testing for known familial melanoma genes is commercially available, clinical implementation has been restrained as utility is unclear, concerns of causing psychological distress are often cited, and consumer interest and perceptions are not well understood. A review of studies exploring participant-reported psychosocial outcomes and attitudes towards genetic testing for familial melanoma will provide insight into common emotional and cognitive responses.

METHODS

Database searches of PubMed, Embase, CINAHL, PsycINFO and the Cochrane Library were conducted using a date range of January 1995 to June 2020. Studies examining any psychosocial outcomes alongside genetic testing (real or hypothetical), in participants described as having a high risk of melanoma, were eligible. A narrative synthesis of results was used to describe psychosocial outcomes and summarise participant beliefs and attitudes towards genetic testing.

RESULTS

Limited evidence of adverse psychosocial outcomes was found. No impacts on perceived risk or control were reported, and minimal decisional regret was recorded. Generalised distress was comparable between both genetic mutation carriers and non-carriers, often decreasing over time from pretesting levels. Melanoma-specific distress was frequently higher in carriers than non-carriers; however, this difference was present prior to testing and often associated with personal melanoma history. Overall, participants' attitudes towards testing were largely positive, with benefits more frequently described than limitations, and support for testing minors was strong.

CONCLUSIONS

This review has found evidence of few adverse psychological outcomes following genetic testing. There was no indication of increased distress after genetic test results had been disclosed. If these findings were replicated in additional, larger, diverse populations over a longer follow-up period, this would be compelling evidence to guide clinical recommendations.

Psychological Impact of Learning CDKN2A Variant Status as a Genetic Research Result

OBJECTIVES

Little is known about genetic research participants' responses to receiving individual research results (IRR) from cancer genetic research. We examined the immediate and delayed psychological impact of returning a CDKN2A variant result that is associated with increased risk of pancreatic cancer and melanoma.

METHODS

One hundred and thirty-three pancreas research registry enrollees whose samples were tested in a research laboratory for the CDKN2A variant were invited by mail to learn the result by telephone and participate in a study about the disclosure process. Self-rated health, quality of life, and emotional responses were surveyed before and 6 months after disclosure. Genetic testing-specific distress, uncertainty, and positive experiences were assessed 6 months after disclosure.

RESULTS

Eighty individuals agreed to participate; 63 completed the study. Both carriers and noncarriers showed no change over time in self-rated health, quality of life, or anxiety levels. Carriers reported more sadness than noncarriers before and 6 months after disclosure. Both carriers and noncarriers showed more hopefulness 6 months after than before disclosure. Carriers experienced greater test-specific distress and uncertainty than noncarriers, but levels were low. -Conclusions: Return of IRR in conjunction with cancer prevention counseling led to low levels of test-specific distress and uncertainty among carriers. No other adverse psychological outcomes were observed.

Genetic susceptibility to cutaneous melanoma in southern Switzerland: role of CDKN2A, MC1R and MITF

BACKGROUND

Nearly 10% of all cases of cutaneous melanoma (CM) occur in patients with a personal or family history of the disease.

OBJECTIVES

To obtain information about genetic predisposition to CM in Ticino, the southern region of Switzerland, a zone with moderate-to-high CM incidence.

METHODS

We identified germline mutations in highly CM-associated genes (CDKN2A and CDK4) and low/medium-penetrance variants (MC1R and MITF) in patients with multiple primary CMs or individuals with one or more CM and a positive family history for CM or pancreatic cancer among first- or second-degree relatives. Healthy blood donors (n = 146) were included as a control group.

RESULTS

From July 2010 to July 2012, 57 patients (41 pedigrees) were included. Twenty-six were melanoma-prone families (with at least two cases) and 15 had multiple CMs. Pancreatic cancer was found in six families. The CDKN2A mutation p.V126D was identified in seven patients (four families) with a founder effect, whereas CDKN2A A148T was detected in seven cases (five families) and seven healthy donors (odds ratio 2·76, 95% confidence interval 0·83-9·20). At least one MC1R melanoma-associated polymorphism was detected in 32 patients (78%) and 97 healthy donors (66%), with more than one polymorphism in 12 patients (29%) and 25 healthy donors (17%). The MITF variant p.E318K was identified in four patients from three additional pedigrees (7%) and one healthy control (0·7%).

CONCLUSIONS

Inclusion criteria for the Ticino population for genetic assessment should follow the rule of two (two affected individuals in a family or a patient with multiple CMs), as we detected a CDKN2A mutation in almost 10% of our pedigrees (four of 41), MITF p.E318K in 7% (three of 41) and a higher number of MC1R variants than in the control population.

Psychiatric implications of cancer genetic testing

As genetic testing for hereditary cancer syndromes has transitioned from research to clinical settings, research regarding its accompanying psychosocial effects has grown. Men and women being tested for hereditary cancer syndromes may experience some psychological distress while going through the process of testing or after carrier status is identified. Psychological distress appears to decrease over the course of the first year and it is typically not clinically significant. Longer term studies show mixed results with some mutation carriers continuing to experience elevated distress. Baseline distress is the greatest risk factor for both immediate (weeks-12 months) and long-term psychological distress (18 mo-8 years post genetic testing). In addition to baseline psychological distress, other risk factors can be identified to help identify individuals who may need psychosocial interventions during the genetic testing process. The challenges of providing clinical care to the growing population of individuals identified to be at increased risk for heritable cancers present opportunities for research and new models of care.

Clinical applications of melanoma genetics

Families that have several relatives with melanoma, multiple primary melanomas in one individual, younger than average ages of melanoma onset, and/or the presence of both pancreatic cancer and melanoma may be suggestive of a hereditary melanoma syndrome and are candidates for genetic counseling and risk assessment. Genetic counseling for hereditary melanoma presents many complexities. Only a minority of hereditary melanoma cases have been attributed to a single genetic factor, CDKN2A. Both the frequency and the penetrance of CDKN2A mutations has been shown to be dependent on multiple factors. The clinical utility of genetic testing for hereditary melanoma families is debatable because CDKN2A status may not impact medical management in patients with melanoma. No standard medical management guidelines exist for families with CDKN2A mutations; however, family history of melanoma and pancreatic cancer may warrant further discussion. Clinicians should discuss the clinical and psychological implications before genetic testing. Genetic counseling and pretest education regarding melanoma risk factors provides an opportunity to increase knowledge and understanding of melanoma risk, while addressing psychological risks and concerns.

Addressing the ethical challenges in genetic testing and sequencing of children

American Academy of Pediatrics (AAP) and American College of Medical Genetics (ACMG) recently provided two recommendations about predictive genetic testing of children. The Clinical Sequencing Exploratory Research Consortium's Pediatrics Working Group compared these recommendations, focusing on operational and ethical issues specific to decision making for children. Content analysis of the statements addresses two issues: (1) how these recommendations characterize and analyze locus of decision making, as well as the risks and benefits of testing, and (2) whether the guidelines conflict or come to different but compatible conclusions because they consider different testing scenarios. These statements differ in ethically significant ways. AAP/ACMG analyzes risks and benefits using best interests of the child and recommends that, absent ameliorative interventions available during childhood, clinicians should generally decline to order testing. Parents authorize focused tests. ACMG analyzes risks and benefits using the interests of the child and other family members and recommends that sequencing results be examined for additional variants that can lead to ameliorative interventions, regardless of age, which laboratories should report to clinicians who should contextualize the results. Parents must accept additional analysis. The ethical arguments in these statements appear to be in tension with each other.

Surveillance of second-degree relatives from melanoma families with a CDKN2A germline mutation

BACKGROUND

Lifetime melanoma risk of mutation carriers from families with a germline mutation in the CDKN2A gene is estimated to be 67%. The necessity to include family members in a melanoma surveillance program is widely endorsed, but there is no consensus on which family members should be invited.

METHODS

In a retrospective follow-up study, we investigated the yield of surveillance of first- and second-degree relatives of melanoma and pancreatic cancer patients from 21 families with the "p16-Leiden" CDKN2A mutation. Melanoma incidence rates were compared with the general population.

RESULTS

Three-hundred and fifty-four first-degree relatives and 391 second-degree relatives were included. Forty-five first-degree relatives and 11 second-degree relatives were diagnosed with melanoma. Most (72%) of second-degree relatives diagnosed with melanoma had become a first-degree relative before diagnosis, due to the occurrence of a melanoma in a parent or sibling. Overall, melanoma incidence rate was 2.1 per 1,000 person years [95% confidence interval (CI), 1.2-3.8] in family members still being second-degree relatives at diagnosis, compared with 9.9 per 1,000 person years (95% CI, 7.4-13.3) in first-degree relatives. The standardized morbidity ratio for melanoma of second-degree relatives compared with the general population was 12.9 (95% CI, 7.2-23.4).

CONCLUSION

Second-degree relatives from families with the p16-Leiden mutation in CDKN2A have a considerably increased melanoma risk compared with the general population.

IMPACT

This study provides justification for the surveillance of second-degree relatives from families with a CDKN2A germline mutation.

Generation after generation: exploring the psychological impact of providing genetic services through a cascading approach

PURPOSE

The provision of genetic services often occurs in a cascading fashion within families experiencing inherited diseases. This study examines whether previous family experiences with genetic services influences levels of psychological well-being of family members receiving services later.

METHODS

Two hundred ninety-seven persons from 38 families with Lynch syndrome completed questionnaires before receiving genetic services. Baseline levels of test-related distress, depressive symptoms, and cancer worries were assessed in relationship to the (1) amount of time elapsed since services were provided to the index case and (2) generation of the family member relative to the index case.

RESULTS

Family members in the same generation as the index case experienced significant increases in test-related distress (P = 0.003) and cancer worry (P = 0.001) with increasing time between receipt of genetic test results by the index case and provision of services to family members. Change in the number of depressive symptoms was not significant (P = 0.17).

CONCLUSION

The provision of genetic services through a cascading approach significantly increases distress and worry among family members within the same generation as the index case who receive services at increasingly distant time intervals. Additional research is needed to explore social influences after the introduction of genetic services.

Genetic testing for hereditary melanoma and pancreatic cancer: a longitudinal study of psychological outcome

OBJECTIVE

CDKN2A/p16 mutations confer 76% lifetime risk of melanoma and up to 17% lifetime risk of pancreatic cancer. Our objective was to determine the short- and long-term impact of CDKN2A/p16 genetic counseling and test reporting on psychological distress, cancer worry, and perceived costs and benefits of testing.

METHODS

Prospective changes in anxiety, depression, and cancer worry following CDKN2A/p16 counseling and test reporting were evaluated at multiple assessments over 2 years among 60 adult members of melanoma-prone families; 37 participants completed the 2-year follow-up. Quantitative and qualitative assessments of the costs and benefits of testing were carried out. Outcomes were evaluated among unaffected noncarriers (n = 27), unaffected carriers (n = 15), and affected carriers (n = 18).

RESULTS

Reported anxiety and depression were low. For carriers and noncarriers, anxiety decreased significantly throughout the 2-year period, whereas depression and melanoma worry showed short-term decreases. Worry about pancreatic cancer was low and decreased significantly. In all groups, test-related distress and uncertainty were low, regret was absent, and positive experiences were high. All participants (>93% at each assessment) reported at least one perceived benefit of genetic testing; only 15.9% listed any negative aspect. Carriers reported increased knowledge about melanoma risk and prevention (78.3%) and increased prevention and screening behaviors for self and family (65.2%). Noncarriers reported increased knowledge (95.2%) and emotional benefits (71.4%).

CONCLUSION

Among US participants familiar with their hereditary melanoma risk through prior epidemiological research participation, CDKN2A/p16 genetic testing provides multiple perceived benefits to both carriers and noncarriers without inducing distress in general or worry about melanoma or pancreatic cancer.

Disclosing individual CDKN2A research results to melanoma survivors: interest, impact, and demands on researchers

BACKGROUND

Whether to return individual research results from cancer genetics studies is widely debated, but little is known about how participants respond to results disclosure or about its time and cost burdens on investigators.

METHODS

We recontacted participants at one site of a multicenter genetic epidemiologic study regarding their CDKN2A gene test results and implications for melanoma risk. Interested participants were disclosed their results by telephone and followed for 3 months.

RESULTS

Among 39 patients approached, 27 were successfully contacted, and 19 (70% uptake) sought results, including three with mutations. Prior to disclosure, participants endorsed numerous benefits of receiving results (mean=7.7 of 9 posed), including gaining information relevant to their children's disease risk. Mean psychological well-being scores did not change from baseline, and no decreases to melanoma prevention behaviors were noted. Fifty-nine percent of participants reported that disclosure made participation in future research more likely. Preparation for disclosure required 40 minutes and $611 per recontact attempt. An additional 78 minutes and $68 was needed to disclose results.

CONCLUSION

Cancer epidemiology research participants who received their individual genetic research results showed no evidence of psychological harm or false reassurance from disclosure and expressed strong trust in the accuracy of results. Burdens to our investigators were high, but protocols may differ in their demands and disclosure may increase participants' willingness to enroll in future studies.

IMPACT

Providing individual study results to cancer genetics research participants poses potential challenges for investigators, but many participants desire and respond positively to this information.

Returning individual research results: development of a cancer genetics education and risk communication protocol

The obligations of researchers to disclose clinically and/or personally significant individual research results are highly debated, but few empirical studies have addressed this topic. We describe the development of a protocol for returning research results to participants at one site of a multicenter study of the genetic epidemiology of melanoma. Protocol development involved numerous challenges: (1) deciding whether genotype results merited disclosure; (2) achieving an appropriate format for communicating results; (3) developing education materials; (4) deciding whether to retest samples for additional laboratory validation; (5) identifying and notifying selected participants; and (6) assessing the impact of disclosure. Our experience suggests potential obstacles depending on researcher resources and the design of the parent study, but offers a process by which researchers can responsibly return individual study results and evaluate the impact of disclosure.

Management of melanoma families

In this review we have aimed to focus on the clinical management of familial melanoma patients and their relatives. Along this line three major topics will be discussed: (1) management/screening of familial melanoma families: what is advised and what is the evidence thereof; (2) variability of families worldwide with regard to clinical phenotype, including cancer spectrum and likelihood of finding germline mutations and (3) background information for clinicians on the molecular biology of familial melanoma and recent developments in this field.