Genetic testing among high-risk individuals in families with hereditary nonpolyposis colorectal cancer

Expanding access to genetic testing for pancreatic cancer

Among individuals with pancreatic ductal adenocarcinoma (PDAC) 5-10% have a pathogenic germline variant (PGV) in a PDAC susceptibility gene. Guidelines recommend genetic testing among all individuals with PDAC. Additionally, at-risk relatives of PDAC patients benefit from their own genetic education, risk assessment, and testing. Multigene panel testing (MGPT) can identify individuals with inherited cancer risk who can benefit from early cancer surveillance and risk reduction strategies. This manuscript discusses various healthcare delivery models for MGPT including traditional in-person genetic counseling, novel integrated in-person infrastructures, telemedicine genetics care via telephone- or video-visits and direct-to-consumer testing. Barriers and facilitators to care on the individual, provider, and system level are also outlined including specific considerations for historically marginalized communities.

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.

Young-onset colorectal cancer

In the past decades the incidence of colorectal cancer (CRC) in people under the age of 50 years has increased, which is referred to as early-onset CRC or young-onset CRC (YO-CRC). YO-CRC is expected to account for 11% of colon cancers and 23% of rectal cancers by 2030. This trend is observed in different parts of the world and in both men and women. In 20% of patients with YO-CRC, a hereditary cancer syndrome is found as the underlying cause; however, in the majority of patients no genetic predisposition is present. Beginning in the 1950s, major changes in lifestyle such as antibiotic use, low physical activity and obesity have affected the gut microbiome and may be an important factor in YO-CRC development. Owing to a lack of screening, patients with YO-CRC are often diagnosed with advanced-stage disease. Long-term treatment-related complications should be taken into account in these younger patients, making the more traditional sequential approaches of drug therapy not always the most appropriate option. To better understand the underlying mechanism and define relationships between environmental factors and YO-CRC development, long-term prospective studies are needed with lifestyle data collected from childhood.

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.

Genetic testing in families with hereditary colorectal cancer in British Columbia and Yukon: a retrospective cross-sectional analysis

BACKGROUND

Genetic testing in families with hereditary cancer enables identification of people most likely to benefit from intensive screening and preventive measures; however, the uptake of testing in relatives (known as cascade carrier testing) for hereditary colorectal cancer syndromes has been shown to be low. Our objective was to report rates of familial testing for hereditary colorectal cancer syndromes in a publicly funded hereditary cancer clinic in Canada.

METHODS

A cross-sectional retrospective database review was used to determine testing uptake between 1997 and 2016 for families served by the provincial Hereditary Cancer Program for British Columbia and Yukon. Analyses were conducted for genes associated with syndromes with an increased risk for colorectal cancer, including Lynch syndrome (MLH1, MSH2, MSH6, PMS2 and EPCAM) and familial adenomatous polyposis (APC), and for additional moderate- to high-penetrance genes (STK11, TP53, SMAD4, MUTYH, PTEN and CHEK2). Descriptive statistics were used and all analyses were 2-tailed.

RESULTS

The study cohort included 245 index patients, with carrier testing performed in 382 relatives. The mean age at family member testing was 41.2 years, and most (61.0%) of the family members who underwent testing were women. The median time between disclosure of index cases and their family member's results was 8.3 months. Among eligible first-degree relatives, 32.6% (268/821) underwent testing in BC. Of 67 cancer diagnoses in family members, most (62.7%) occurred before genetic testing.

INTERPRETATION

A substantial proportion of people at risk for hereditary colorectal cancer do not undergo genetic testing. This gap highlights the need to explore barriers to testing and to consider interventions to promote uptake; more aggressive efforts by hereditary cancer programs are needed to reach this highest risk population.

Deficiency of hMLH1 and hMSH2 expression is a poor prognostic factor in Early Gastric Cancer (EGC)

Purpose: The aim of the study was to investigate the effect of deficiency of hMLH1 and hMSH2 expression on the prognosis of early gastric cancer (EGC) in Chinese populations.

Methods: A total of 160 EGC patients who underwent curative gastrectomy with lymphadenectomy from January 2011 to July 2014 at Xinhua Hospital were evaluated. The expression rates of hMLH1 and hMSH2 were examined using tissues preserved in paraffin blocks by immunohistochemical staining. The clinicopathological characteristics and prognosis of EGC with deficient hMLH1 and hMSH2 were analyzed.

Results: On immunohistochemical staining, the loss expression of hMLH1 and hMSH2 were observed in 89 (55.6%) and 45 (28.1%), respectively. The hMLH1 deficiency was associated with the middle third of tumor location (P = 0.041). According to Kaplan-Meier survival analysis and Log-Rank test, the loss expression of hMLH1 and hMSH2 were associated with worse survival than positive hMLH1 (HR = 0.247, 95% CI = 0.078-0.781, P = 0.017) and hMSH2 (HR = 0.174, 95% CI = 0.051-0.601, P = 0.006) in EGC.

Conclusion: The main conclusions were as follows: The hMLH1 deficiency was preferred to the middle third of EGC. Lymph node metastasis (LNM) was a prognostic factor of EGC. And the prognosis of EGC patients with deficient mismatch repair (dMMR, mainly including deficient hMLH1 and hMSH2) was obviously worse than proficient mismatch repair (pMMR).

Development of the Informing Relatives Inventory (IRI): Assessing Index Patients' Knowledge, Motivation and Self-Efficacy Regarding the Disclosure of Hereditary Cancer Risk Information to Relatives

BACKGROUND

Despite the use of genetic services, counselees do not always share hereditary cancer information with at-risk relatives. Reasons for not informing relatives may be categorized as a lack of: knowledge, motivation, and/or self-efficacy.

PURPOSE

This study aims to develop and test the psychometric properties of the Informing Relatives Inventory, a battery of instruments that intend to measure counselees' knowledge, motivation, and self-efficacy regarding the disclosure of hereditary cancer risk information to at-risk relatives.

METHOD

Guided by the proposed conceptual framework, existing instruments were selected and new instruments were developed. We tested the instruments' acceptability, dimensionality, reliability, and criterion-related validity in consecutive index patients visiting the Clinical Genetics department with questions regarding hereditary breast and/or ovarian cancer or colon cancer.

RESULTS

Data of 211 index patients were included (response rate = 62%). The Informing Relatives Inventory (IRI) assesses three barriers in disclosure representing seven domains. Instruments assessing index patients' (positive) motivation and self-efficacy were acceptable and reliable and suggested good criterion-related validity. Psychometric properties of instruments assessing index patients knowledge were disputable. These items were moderately accepted by index patients and the criterion-related validity was weaker.

CONCLUSION

This study presents a first conceptual framework and associated inventory (IRI) that improves insight into index patients' barriers regarding the disclosure of genetic cancer information to at-risk relatives. Instruments assessing (positive) motivation and self-efficacy proved to be reliable measurements. Measuring index patients knowledge appeared to be more challenging. Further research is necessary to ensure IRI's dimensionality and sensitivity to change.

Long-term psychosocial and behavioral adjustment in individuals receiving genetic test results in Lynch syndrome

A cross-sectional study of 155 participants who underwent genetic testing for Lynch syndrome (LS) examined long-term psychosocial and behavioral outcomes. Participants completed standardized measures of perceived risk, psychosocial functioning, knowledge, and a questionnaire of screening activities. Participants were on average 47.3 years and had undergone testing a mean of 5.5 years prior. Eighty four (54%) tested positive for a LS mutation and 71 (46%) negative. For unaffected carriers, perceived lifetime risk of colorectal cancer was 68%, and surprisingly, 40% among those testing negative. Most individuals demonstrated normative levels of psychosocial functioning. However, 25% of those testing negative had moderate depressive symptoms, as measured by the Center for Epidemiologic Studies for Depression Scale, and 31% elevated state anxiety on the State-Trait Anxiety Inventory. Being female and a stronger escape - avoidant coping style were predictive of depressive symptoms. For state anxiety, similar patterns were observed. Quality of life and social support were significantly associated with lower anxiety. Carriers maintained higher knowledge compared to those testing negative, and were more engaged in screening. In summary, most individuals adapt to genetic test results over the long term and continue to engage in screening. A subgroup, including some non-carriers, may require added psychosocial support.

Reflex testing for Lynch syndrome: if we build it, will they come? Lessons learned from the uptake of clinical genetics services by individuals with newly diagnosed colorectal cancer (CRC)

The aim of this qualitative study was to examine the experience of individuals facing a choice about genetic counselling/testing in the context of newly diagnosed colorectal cancer (CRC). Nineteen individuals with newly diagnosed CRC, including 12 individuals who accepted genetic counselling (“acceptors”) and 7 individuals who declined genetic counselling (“refusers”), were interviewed using a standardized questionnaire guide which focused on motivations and barriers experienced in the decision process. Data were analyzed using Karlsson’s Empirical Phenomenological method of data analysis (Karlsson in Psychological qualitative research from a phenomenological perspective. Almgvist and Wiksell International, Stockholm, 1993). Three major themes were identified: facing challenges in health literacy; mapping an unknown territory; and adjusting to cancer. The study participants’ testimonies provided novel insights into potential reasons for patient non-engagement in pilot studies of reflex testing for Lynch syndrome, and allowed us to formulate several recommendations for enhancing patient engagement. Our study findings suggest that patient engagement in clinical cancer genetics services, including reflex testing for Lynch syndrome, can only be achieved by addressing current health literacy issues, by deconstructing current misconceptions related to potential abuses of genetic information, by emphasizing the clinical utility of genetic assessment, and by adapting genetics practices to the specific context of cancer care.

Colonoscopy screening compliance and outcomes in patients with Lynch syndrome

AIM

Colonic surveillance reduces the lifetime risk of colorectal cancer in patients with Lynch syndrome (hereditary nonpolyposis colorectal cancer) from 60 to 80% to 10% and confers a 7-year survival advantage. The British Society of Gastroenterologists recommends colonoscopy at least every 2 years from the age of 25. Currently in the UK, genetic diagnosis is made by a regional genetics service, and screening recommendations are made to the referring clinician. The aim of this study was to investigate compliance with and the effectiveness of large bowel surveillance in Lynch syndrome.

METHOD

A retrospective longitudinal study of Lynch syndrome mutation carriers on the Regional Familial Colorectal Cancer Registry under and not under screening was conducted. To investigate screening compliance, patients were included if they were alive at the start of the study. Data were gathered on timeliness, quality and outcome of screening. To examine the effectiveness of screening, the cumulative incidence of colorectal cancer was estimated using Kaplan-Meier curves and the screened population compared with patients not being screened.

RESULTS

A total of 227 Lynch syndrome mutation carriers were under screening at 26 hospitals. We assessed 439 colonoscopies for timeliness, of which 68% were compliant (interval < 27 months). Compliance on the 1 November 2011 was 87%. The cumulative incidence of colorectal cancer to the age of 70 was 25% (95% CI 17-32%) in the surveillance population and 81% (95% CI 78-84%) in 689 mutation-positive patients not being screened (P < 0.0001).

CONCLUSION

Overall, 68% of colonoscopies were on time. The incidence of colorectal cancer was greatly reduced by screening but remained significant. Patients with Lynch syndrome need proactive surveillance management.

Incidence, clinical features and possible etiology of early onset (≤40 years) colorectal neoplasms

The aim of the study was to investigate the clinical features, including survival, of patients with colorectal malignancies developed at a very early age (≤40 years), together with possible factors involved in the pathogenesis of these rare neoplasms. The study took advantage of the existence of a specialized colorectal cancer Registry active from 1984. 57 patients met the criteria of early onset cancer; main epidemiological data, morphology, stage, familial aggregation, possible role of inheritance and survival were analyzed. Despite the relevant increase over time of all registered patients, joiningpoint analysis of crude incidence rate of early onset colorectal neoplasms revealed a certain stability of these tumors (EAPC: 2.4, CI 14-22) with a constant prevalence of the male sex. Stage at diagnosis did not show significant variations between early onset and maturity onset colorectal neoplasms. Hereditary as well as familial cases were significantly (P < 0.005 and 0.03) more frequent among patients with early onset tumors, although in the majority of them no specific etiological factor could be identified. Survival was more favorable in patients with early onset tumors, though this had to be attributed to the higher presence of some histological types in early onset cases. Survival was significantly more favorable for patients of all ages registered in the last decade. Incidence of early onset colorectal cancer was relatively stable between 1984 and 2008. A male preponderance was evident through the registration period. Hereditary and familial cases were significantly more frequent among early onset case. A well defined etiology could be observed in 16% of the cases (versus 2-3% in older individuals). Five-year survival showed a significant improvement over time.

History, genetics, and strategies for cancer prevention in Lynch syndrome

Colorectal cancer (CRC) is the most common gastrointestinal malignancy and the third cause of cancer death in men and women in the United States. The majority of CRC cases diagnosed annually are due to sporadic events, but up to 6% are attributed to known monogenic disorders that confer a markedly increased risk for the development of CRC and multiple extracolonic malignancies. Lynch syndrome is the most common inherited CRC syndrome and is associated with mutations in DNA mismatch repair genes, mainly MLH1 and MSH2 but also MSH6, PMS2, and EPCAM. Although the risk of CRC and endometrial cancer may approach near 75% and 50%, respectively, in gene mutation carriers, the identification of these individuals and at-risk family members through predictive genetic testing provides opportunities for cancer prevention including specialized cancer screening, intensified surveillance, and/or prophylactic surgeries. This article will provide a review of the major advances in risk assessment, molecular genetics, DNA mutational analyses, and cancer prevention and management made since Lynch syndrome was first described 100 years ago.

Informing relatives about their hereditary or familial cancer risk: study protocol for a randomized controlled trial

BACKGROUND

Genetic counseling for hereditary breast or colon cancer has implications for both counselees and their relatives. Although counselees are encouraged by genetic counselors to disclose genetic cancer risk information, they do not always share this information with their at-risk relatives. Reasons for not informing relatives may be generally categorized as a lack of knowledge, motivation and/or self-efficacy. Presented here is the protocol of a randomized controlled trial that aims to establish the effectiveness of an intervention focused on supporting counselees in their disclosure of genetic cancer information to their relatives.

METHODS/DESIGN

A multicenter randomized controlled trial with parallel group design will be used to compare the effects of an additional telephone counseling session performed by psychosocial workers to enhance the disclosure of genetic cancer information to at-risk relatives (intervention group) with a control group of standard care. Consecutive index patients with relatives at risk for hereditary or familial breast and/or ovarian cancer or colon cancer, are randomly assigned (block size: 8; 1:1 allocation ratio) to the intervention (n = 132) or control group (n = 132, standard care). Primary outcomes are counselees' knowledge, motivation and self-efficacy regarding informing their relatives.

DISCUSSION

This intervention may prove important in supporting counselees to disclose hereditary and/or familial cancer risk information to at-risk relatives and may enable more at-risk relatives to make a well-informed decision regarding genetic services and/or screening.

TRIAL REGISTRATION

This trial is registered in the Netherlands National Trial Register (NTR) with trial ID number NTR3745.

Incidence trend of malignant polyps through the data of a specialized colorectal cancer registry: clinical features and effect of screening

OBJECTIVES

The purposes of the study are to describe the incidence trend of malignant polyp of large bowel over a 25-year period in the District of Modena and to assess the effect of an organized colorectal cancer screening program.

MATERIAL AND METHODS

Through the data of a specialized colorectal cancer Registry, we evaluate the clinical and pathological features of the polyps. Trend analysis was assessed with the Joinpoint Regression Program.

RESULTS

A total of 172 patients with malignant polyps were diagnosed throughout the study (3.5% of 4.835 registered patients); their overall frequency during the registration period increased from zero cases in the initial years (1984-85) to 57 cases in the past 3 years (2006-2008). Crude incidence rate passed from 0.37 in 1986-89 to 10.2 in 2006. Joinpoint trend analysis of crude rates showed a significant increase of incidence during the study period, with percent of annual variation ranging between 38.6% (95% CI 12.5-70.7) and 7.3% (95% CI 2.6-12.1). During the screening period (2005-2008, the past 4 years of registration) there was a significant increase of sessile polyps (p < 0.001), while other clinical and morphological features, including the number of low- and high-risk malignant polyps, remained unchanged. The surgery (after polypectomy) tended to raise both in low- and high-risk subgroups.

CONCLUSION

The incidence of malignant polyps increased significantly from the initial to the most recent periods of colorectal cancer registration. Screening was associated with changes in gross morphology of polyps and with an increased use of the surgery after endoscopic polypectomy.

Uptake of genetic testing by relatives of lynch syndrome probands: a systematic review

BACKGROUND & AIMS

Screening of persons with newly diagnosed colorectal cancer for Lynch syndrome can yield substantial benefits at acceptable costs, presuming sufficient uptake of genetic testing by first-degree relatives of Lynch syndrome probands. We performed a systematic review of the literature to determine the frequency of and factors associated with genetic testing of first-degree relatives of Lynch syndrome probands.

METHODS

We searched 4 databases (CINAHL, PsycInfo, PUBMED, and SCOPUS) for articles published through May 2011 reporting uptake of genetic testing by relatives of Lynch syndrome probands. Two investigators independently screened articles to determine whether they met inclusion criteria; data were collected on study population, genetic counseling, and genetic testing. A narrative, qualitative systematic review was performed.

RESULTS

We identified 1258 potentially relevant articles; 533 underwent full-text review, and 8 were included in the final analysis. Of first-degree relatives of Lynch syndrome probands, 52% or less received genetic testing. For each proband, 3.6 or fewer relatives underwent genetic testing. Demographic factors (age <50 years, female sex, parenthood, level of education, employment, participation in medical studies), psychological factors (lack of depressive symptoms), and possibly family history (greater number of relatives with cancer) were associated with uptake of genetic testing.

CONCLUSIONS

Genetic testing appears to be underutilized by first-degree relatives of patients with Lynch syndrome. The clinical benefit and economic feasibility of screening persons with colorectal cancer for Lynch syndrome depend on optimizing family-wide uptake of genetic testing. Future research and clinical efforts should focus on ways to overcome barriers to genetic testing.

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.

Attitudes of patients with cancer about personalized medicine and somatic genetic testing

PURPOSE

Dramatic advances in genomic technology stand to revolutionize cancer care; however, little is known about patients' understanding and acceptance of personalized medicine and widespread genetic testing (GT).

PATIENTS AND METHODS

We conducted a formative, semi-structured interview study with a random sample of patients with lung, colorectal, and breast cancers to assess awareness of personalized medicine and GT and attitudes about somatic GT. Willingness to undergo GT was elicited through hypothetic scenarios.

RESULTS

Sixty-nine patients participated; 71% were women; 42% were black; median age was 59 years; and 42% had an education level ≥ college. We found that a majority of patients either were not aware of the term "personalized medicine" or defined it in unexpected ways. Although many patients identified relevant benefits of somatic testing (eg, informs treatment), many patients also expressed significant concerns (ie, psychological harm and discrimination). A majority of patients expressed a willingness to undergo somatic (predictive, 96%, prognostic, 93%) and germline (cancer risk without incidental information, 87%; cancer risk with incidental information, 81%; pharmacogenetic, 91%) testing; however, far fewer patients expressed a willingness to undergo full genome sequencing (62%). Reluctance was attributed to concerns over incidental findings, information overload, and the lack of a clear benefit.

CONCLUSION

Many patients relayed misunderstandings about somatic testing and a reluctance to undergo full sequencing; oncologists must carefully consider how they present testing to patients so that concerns over discrimination and psychological harm do not hinder test uptake. More work is needed to identify effective ways to communicate complex genomic concepts to patients and research participants.

Attitudes of patients with cancer about personalized medicine and somatic genetic testing

PURPOSE

Dramatic advances in genomic technology stand to revolutionize cancer care; however, little is known about patients' understanding and acceptance of personalized medicine and widespread genetic testing (GT).

PATIENTS AND METHODS

We conducted a formative, semi-structured interview study with a random sample of patients with lung, colorectal, and breast cancers to assess awareness of personalized medicine and GT and attitudes about somatic GT. Willingness to undergo GT was elicited through hypothetic scenarios.

RESULTS

Sixty-nine patients participated; 71% were women; 42% were black; median age was 59 years; and 42% had an education level ≥ college. We found that a majority of patients either were not aware of the term "personalized medicine" or defined it in unexpected ways. Although many patients identified relevant benefits of somatic testing (eg, informs treatment), many patients also expressed significant concerns (ie, psychological harm and discrimination). A majority of patients expressed a willingness to undergo somatic (predictive, 96%, prognostic, 93%) and germline (cancer risk without incidental information, 87%; cancer risk with incidental information, 81%; pharmacogenetic, 91%) testing; however, far fewer patients expressed a willingness to undergo full genome sequencing (62%). Reluctance was attributed to concerns over incidental findings, information overload, and the lack of a clear benefit.

CONCLUSION

Many patients relayed misunderstandings about somatic testing and a reluctance to undergo full sequencing; oncologists must carefully consider how they present testing to patients so that concerns over discrimination and psychological harm do not hinder test uptake. More work is needed to identify effective ways to communicate complex genomic concepts to patients and research participants.

Perception of direct-to-consumer genetic testing and direct-to-consumer advertising of genetic tests among members of a large managed care organization

This small qualitative study was designed to determine possible attitudes toward and understanding of direct-to-consumer (DTC) genetic testing among members of a large managed care organization, and whether differences might exist between population groups. Ten focus groups were conducted by population type (high risk, White, African American, Hispanic/Latino) to determine knowledge, attitudes and beliefs about DTC genetics. Focus group transcripts were coded for attitudes toward and framing of the issue. Study results found participants were negative towards DTC genetic testing but they also found some aspects useful. Participants framed the issue mainly in terms of disease prevention and uncertainty of reaction to results, with some variation between population types. The concept of an "Informed Consumer," or process to seek information when the issue becomes personally relevant, emerged. This concept suggests that individuals may seek additional assistance to make personally-appropriate choices when faced with a DTC advertisement or genetic test.

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.

An American founder mutation in MLH1

Mutations in the mismatch repair genes cause Lynch syndrome (LS), conferring high risk of colorectal, endometrial and some other cancers. After the same splice site mutation in the MLH1 gene (c.589-2A>G) had been observed in four ostensibly unrelated American families with typical LS cancers, its occurrence in comprehensive series of LS cases (Mayo Clinic, Germany and Italy) was determined. It occurred in 10 out of 995 LS mutation carriers (1.0%) diagnosed in the Mayo Clinic diagnostic laboratory. It did not occur among 1,803 cases tested for MLH1 mutations by the German HNPCC consortium, while it occurred in three probands and an additional five family members diagnosed in Italy. In the U.S., the splice site mutation occurs on a large (∼4.8 Mb) shared haplotype that also harbors the variant c.2146G>A, which predicts a missense change in codon 716 referred to here as V716M. In Italy, it occurs on a different, shorter shared haplotype (∼2.2 Mb) that does not carry V716M. The V716M variant was found to be present by itself in the U.S., German and Italian populations with individuals sharing a common haplotype of 280 kb, allowing us to calculate that the variant arose around 5,600 years ago (225 generations; 95% confidence interval 183-272). The splice site mutation in America arose or was introduced some 450 years ago (18 generations; 95% confidence interval 14-23); it accounts for 1.0% all LS in the Unites States and can be readily screened for.

Ethical, legal and social implications of prenatal and preimplantation genetic testing for cancer susceptibility

With the progress in cancer genetics and assisted reproductive technologies, it is now possible for cancer gene mutation carriers not only to reduce cancer mortality through the targeting of surveillance and preventive therapies, but also to avoid the birth of at-risk babies through the choice of different means of reproduction. Thus, the incidence of hereditary cancer syndromes may be decreased in the future. The integration of cancer genetic testing and assisted reproductive technologies raises certain ethical, legal and social issues beyond either genetic testing or assisted reproductive technology itself. In this paper, the reproductive decisions/choices of at-risk young couples and the ethical, legal and social concerns of prenatal genetic testing and preimplantation genetic diagnosis for susceptibility to hereditary cancer syndromes are discussed. Specifically, three ethical principles related to the integration of cancer genetic testing and assisted reproductive technologies, i.e. informed choice, beneficence to children and social justice, and their implications for the responsible translation of these medical techniques into common practice of preventive medicine are highlighted.

Screening participation in individuals with a family history of colorectal cancer: a review

Literature regarding screening behaviour in individuals with a family history of colorectal cancer was reviewed, in order to determine the prevalence of screening in this population and identify factors associated with screening participation. Four electronic databases were searched from 1994. Thirty papers met the inclusion criteria, including 3 community surveys, 13 studies on first-degree relatives of colorectal cancer patients, and 14 studies on genetic services for colorectal cancer risk assessment. Individuals with a family history of colorectal cancer, who have not received risk assessment, frequently have never had any form of screening for colorectal cancer. Uptake of endoscopic screening when offered to individuals identified as being at increased risk was generally high (often >60% participation). Having a medical recommendation to screen, a stronger family history and perceiving fewer barriers to screening were identified as predictors of screening behaviour. Existing data suggest that use of screening tests in individuals with a family history of colorectal cancer is variable, and our understanding of factors associated with screening behaviour is limited. A number of methodological problems in research to date were identified, and further research is needed in order to inform interventions to support sustained screening participation in this population.

Cascade genetic testing for mismatch repair gene mutations

Mismatch repair gene mutation carriers have a high risk of developing colorectal cancer, and can benefit from appropriate surveillance. A combined population based ascertainment cascade genetic testing approach provides a systematic and potentially effective strategy for identifying such carriers. We have developed a Markov Chain computer model system which simulates various factors influencing cascade genetic testing; including demographics, uptake, genetic epidemiology and family size. This was used to evaluate cascade genetic testing for mismatch repair gene mutations in theory and practice. Simulations focussed on the population of Scotland by way of illustration, and were based on a 20-year programme in which index cases were ascertained from colorectal cancer cases aged<55 years at onset. Results indicated that without practical barriers to cascade genetic testing, 545 (95% CI=522, 568) carriers could be identified; 42% of the population total. This comprised approximately 140 index cases, 302 asymptomatic relatives and 104 previously affected relatives. However, when realistic ascertainment and acceptance rates were used to inform simulations, only 257 (95% CI=246, 268) carriers, about 20% of the carrier population, were identifiable. Of these approximately 112 were index cases, 108 were asymptomatic relatives, and 37 were previously affected relatives. This contrast emphasises the importance of ascertainment and acceptance rates. Likewise the low number of index cases shows that case identification is a limiting factor. In the absence of robust data from epidemiological studies, these findings can inform decisions about the use of cascade genetic testing for mismatch repair gene mutations.

Syndromic colon cancer: lynch syndrome and familial adenomatous polyposis

Colon cancer, the third leading cause of mortality from cancer in the United States, afflicts about 150,000 patients annually. More than 10% of these patients exhibit familial clustering. The most common and well characterized of these familial colon cancer syndromes is hereditary nonpolyposis colon cancer syndrome (Lynch syndrome), which accounts for about 2% to 3% of all cases of colon cancer in the United States. We review the current knowledge of familial cancer syndromes, with an emphasis on Lynch syndrome and familial adenomatous polyposis.

A systematic review of perceived risks, psychological and behavioral impacts of genetic testing

Genetic testing may enable early disease detection, targeted surveillance, and result in effective prevention strategies. Knowledge of genetic risk may also enable behavioral change. However, the impact of carrier status from the psychological, behavior, and perceived risk perspectives is not well understood. We conducted a systematic review to summarize the available literature on these elements. An extensive literature review was performed to identify studies that measured the perceived risk, psychological, and/or behavioral impacts of genetic testing on individuals. The search was not limited to specific diseases but excluded the impacts of testing for single gene disorders. A total of 35 articles and 30 studies were included. The studies evaluated hereditary nonpolyposis colorectal carcinoma, hereditary breast and ovarian cancer, and Alzheimer disease. For affective outcomes, the majority of the studies reported negative effects on carriers but these were short-lived. For behavioral outcomes, an increase in screening behavior of varying rates was demonstrated in carriers but the change in behaviors was less than expected. With respect to perceived risk, there were generally no differences between carriers and noncarriers by 12 months after genetic testing and over time risk perception decreased. Overall, predispositional genetic testing has no significant impact on psychological outcomes, little effect on behavior, and did not change perceived risk. It seems as though better patient education strategies are required. Our data would suggest better knowledge among carriers would not have significant psychological impacts and therefore, it is worth pursuing improved educational strategies.

The impact of predictive genetic testing for hereditary nonpolyposis colorectal cancer: three years after testing

BACKGROUND

To fully assess predictive genetic testing programs, it is important to assess outcomes over periods of time longer than the 1-year follow-up reported in the literature.

METHODS

We conducted a 3-year study of individuals who received predictive genetic test results for previously identified familial mutations in Australian Familial Cancer Clinics. Questionnaires were sent before attendance at the familial cancer clinic and 2 weeks, 4 months, 1 year, and 3 years after receiving test results. Psychological measures were included each time, and preventive behaviors were assessed at baseline and 1 and 3 years. Psychological measures were adjusted for age, gender, and baseline score.

RESULTS

The study included 19 carriers and 54 non-carriers. We previously reported an increase in mean cancer-specific distress in carriers at 2 weeks with a return to baseline levels by 12 months. This level was maintained until 3 years. Non-carriers showed sustained decreases after testing with a significantly lower level at 3 years compared with baseline (P < 0.001). These scores tended to be lower than those for carriers at 3 years (P = 0.09). Mean depression and anxiety scores did not differ between carriers and non-carriers and, at 3 years, were similar to baseline. All carriers and 7% of non-carriers had had a colonoscopy by 3 years, and 69% of 13 female carriers had undergone gynecological screening in the previous 2 years. Prophylactic surgery was rare.

CONCLUSION

This report of long-term data indicates appropriate screening and improved psychological measures for non-carriers with no evidence of undue psychological distress in carriers of hereditary nonpolyposis colorectal cancer mutations.

Development of colorectal tumors in colonoscopic surveillance in Lynch syndrome

BACKGROUND & AIMS

Mutation carriers in Lynch syndrome families have a high risk for developing colorectal cancer during their lifetime. This study was designed to assess the cumulative risk for the development of colorectal adenoma or carcinoma in prospective colonoscopic surveillance.

METHODS

Data from the Finnish Hereditary Colorectal Cancer Registry electronic database on 420 Lynch syndrome mutation carriers without previous colorectal tumors were reviewed. Between March 1982 and May 2005 the mutation carriers underwent a total of 1252 colonoscopies. The total follow-up time was 3150 years (mean, 6.7 y/patient).

RESULTS

The cumulative risk of adenoma by age 60 was estimated as 68% (95% confidence interval [CI], 50%-80%) in men and 48% (95% CI, 29%-62%) in women. The estimated cumulative risk up to age 60 years for the development of cancer found as a result of surveillance at an interval of 2-3 years was 35% (95% CI, 16%-49%) in men and 22% (95% CI, 7%-34%) in women. Half of the adenomas were located proximal to the splenic flexure. Extracolonic cancer was diagnosed in 73 patients (18%).

CONCLUSIONS

Adenoma would appear to be the most important lesion preceding cancer formation in Lynch syndrome and removal of adenomas decreases the risk for colorectal cancer (CRC). The Finnish surveillance protocol of colonoscopies at 2- to 3-year intervals facilitates patient adherence but includes an essential risk for CRC up to 60 years of age, but without CRC-related mortality when the surveillance instructions are followed.

Colorectal cancer survivors undergoing genetic testing for hereditary non-polyposis colorectal cancer: motivational factors and psychosocial functioning

Hereditary non-polyposis colorectal cancer (HNPCC) represents about 1-3% of all cases of colorectal cancer (CRC). The objectives of the study were to examine motivational factors, expectations and psychosocial functioning in a sample of CRC survivors undergoing genetic testing for HNPCC. A cross-sectional survey of 314 colorectal cancer patients recruited through a population-based colon cancer family registry was conducted. Motivations for genetic testing for hereditary cancer were similar to those of clinic-based samples of CRC patients and included learning of the increased risk to offspring and finding out if additional screening was needed. While age at diagnosis and sex were associated with psychological functioning, significant predictors of post-counseling distress were perceived lower satisfaction with social support, an escape-avoidant coping style and the anticipation of becoming depressed if a mutation was present. Most cancer survivors anticipated disclosing test results to relatives and physicians. Cancer survivors reported several motivations for genetic testing for HNPCC that varied by sex. A subgroup of survivors with lower satisfaction with social support and an escape-avoidant coping style were worried about the potential impact of genetic test results and demonstrated more distress following counseling. Findings have implications for future research and potential support needs during the genetic counseling and testing process.

Discrepancies between estimated and perceived risk of cancer among individuals with hereditary nonpolyposis colorectal cancer

Communicating cancer risk and recommending adequate control programs is central for genetic counseling. Individuals affected by hereditary nonpolyposis colorectal cancer (HNPCC) are at about 80% life-time risk of colorectal cancer and for female carriers 40-60% risk of endometrial cancer and 10-15% risk of ovarian cancer. The perceived risk among mutation carriers may, however, deviate from the risk communicated and has been demonstrated to influence adherence to control programs. We investigated the perceived cancer risk among HNPCC mutation carriers (n = 47) and correlated the findings to individual characteristics. A perceived risk of colorectal cancer above 60% was reported by 22/45 individuals, and only one out of five mutation carriers reported a perceived risk > 80%. Female mutation carriers, individuals below age 50, and individuals who received their oncogenetic counseling within 1 year prior to the study reported higher, albeit not significantly, perceived risks of colorectal cancer. Higher perceived risks were also reported by individuals who had lost a parent to HNPCC-related cancer at early age, whereas individuals with a personal history of cancer did not report a higher perceived risk. Regarding gynecological cancer, 6/18 females reported a perceived risk of 40-60% for endometrial cancer, whereas the remaining women both underestimated and overestimated their risk, and none of the women referred to the risk of ovarian cancer. We conclude that despite educational efforts and an increasing amount of data on the cancer risk in HNPCC, a minority of the mutation carriers report a perceived risk at the same level as that communicated during oncogenetic counseling.

Risk reduction and health promotion behaviors following genetic testing for adult-onset disorders

Although clinical genetic testing is available for over 1,000 inherited disorders, consequences of predictive genetic testing have been most extensively examined for hereditary breast and ovarian cancer (HBOC), hereditary colon cancer, and Huntington disease (HD). These focus primarily on psychological, ethical, legal, and social aspects of genetic testing. Genetic testing may also provide information that can lead to behaviors that promote health and reduce risk for disease, reflecting options available for the disorder for which the person is at risk. However, regardless of condition, people completing a genetic test may inform relatives about the results of the test and implications for their risk to develop the condition. Literature on risk reduction behaviors and communication focuses on families with HBOC or colorectal cancer. Few reports document behaviors for other conditions. This paper presents a systematic review of the research literature on risk reduction and health promotion behaviors following clinical genetic testing for adult onset conditions, primarily HBOC, familial colon cancers, and HD. Insights gleaned from this review are discussed as a basis for planning monitoring of health promotion and risk-reduction behaviors for genetic testing for present and future use.

A novel MSH2 germline mutation in a Druze HNPCC family

Germline mutations in DNA mismatch repair (DNA-MMR) genes, mainly MLH1, MSH2, and MSH6, underlie Hereditary non-polyposis colorectal cancer (HNPCC) and are mostly family-specific, with few reported founder mutations in MSH2 (Ashkenazim) MLH1 (Finnish). No mutations in colon cancer susceptibility genes have ever been reported in Druze individuals, a Moslem related faith encompassing approximately 1,000,000 individuals worldwide. A novel MSH2 mutation is described in a Druze HNPCC family: a multigenerational family with 10 members in 4 generations affected with colorectal cancer (mean age of diagnosis 46.5 years), two with gastric cancer and one--endometrial cancer. Mutational analysis of the MSH2 gene using denaturing gradient gel electrophoresis (DGGE) and direct sequencing revealed the c.702delA mutation in codon 234 of exon 4 of the MSH2 gene leading to a premature early stop in codon 245, p.Thr234fsX245. Analysis of mutation-carrying or presumed carriers individuals' offspring, revealed 11/42 asymptomatic mutation carriers, age range 17-50 years. The mutation was not present in two additional Druze HNPCC families and 20 Druze sporadic colon cancer patients. This is the first mutation ever reported in a colon cancer susceptibility gene in a Druze family and it appears not to be a founder mutation in Druze individuals with HNPCC.

Direct contact in inviting high-risk members of hereditary colon cancer families to genetic counselling and DNA testing

BACKGROUND

Identification of hereditary predisposition to cancer has limited significance if not followed by efficient cancer prevention in the family. Probands are traditionally left to inform their relatives about the increased risk, but distant relatives may remain uninformed. An approach to contacting directly at-risk persons assumed to be unaware of their increased cancer risk was taken. With cancer prevention as the ultimate goal, the study was aimed at investigating attitudes towards and psychosocial consequences of this novel strategy.

METHODS

In families with hereditary non-polyposis colorectal cancer (Lynch syndrome), 286 healthy adult relatives with a 50% risk of a predisposing mutation were contacted by letter. Of these, 112 participated in counselling and predictive testing. Baseline information and information obtained 1 month after the test for 73 respondents were compared with 299 corresponding subjects, approached via the proband (family-mediated approach in our previous study) in these families.

RESULTS

After the contact letter, 51% consented to the study. Of these, 92% approved of the direct contact and 33% had tried to seek information. In 34% of the mutation carriers, neoplasia was identified in the first post-test colonoscopy. Although post-test fear of cancer increased among the mutation carriers and decreased among noncarriers, almost all participants were satisfied with their decision to participate, independently of their test results, parallel to the family-mediated approach.

CONCLUSION

In this large-scale study, relatives in cancer families were actively contacted to inform them of the condition and genetic counselling. Their attitudes were encouraging, and the psychosocial consequences were similar to the family-mediated approach. Our results suggest the appropriateness of direct contact as an alternative method of contact in cases of life-threatening treatable disease.

Genotype-phenotype correlations in individuals with a founder mutation in the MLH1 gene and hereditary non-polyposis colorectal cancer

OBJECTIVE

A unique mutation of the MLH1 gene was recently reported in six families living in a small area of Northern Italy. The mutation consists in the insertion of a T base between nucleotides 2269 and 2270 (2269-2270insT), causing the synthesis of an unstable polypeptide. The mutation was not reported by other investigators or outside this small geographic area, thus suggesting a possible founder effect. The main purpose of this investigation was to investigate whether patients (and families) with the 2260-2270insT mutation show relevant clinical differences when compared with individuals with other MLH1 or MSH2 gene alterations.

MATERIAL AND METHODS

We identified hereditary non-polyposis colorectal cancer (HNPCC) families through the specialized colorectal cancer registry following a previously described multistep approach. In all, 58 HNPCC families were identified; of these, 38 were detected through the registry, and 20 were referred from other areas in Italy.

RESULTS

Small differences were found in the main clinical and pathologic features; however, tumour burden per family tended to be higher in kindred sharing the founder mutation; in addition, multiple primaries (four or five different tumours in some subjects) were significantly more frequent in patients with the 2269-2270insT than in individuals with MSH2, MLH1 gene mutations or sporadic colorectal neoplasms. No significant difference in prognosis was found between patients with the founder mutation and those with other MLH1 or MSH2 mutations. Regardless of the type of mutation, neoplasms of the colon-rectum, stomach and endometrium represented nearly 80% of the tumour burden in families with HNPCC.

CONCLUSIONS

A proclivity to multiple tumours arising in the same subject and a higher tumour burden per family were the most relevant findings observed in affected patients with the founder mutation compared with other MLH1 or MSH2 mutations. In general, the results of the study underline the difficulty in discriminating between Lynch I and Lynch II syndromes on the basis of specific molecular changes.

Tumour markers in colorectal cancer: European Group on Tumour Markers (EGTM) guidelines for clinical use

The aim of this article is to present updated guidelines for the use of serum, tissue and faecal markers in colorectal cancer (CRC). Lack of specificity and sensitivity preclude the use of all existing serum markers for the early detection of CRC. For patients with stage II or stage III CRC who may be candidates for either liver resection or systemic treatment should recurrence develop, CEA should be measured every 2-3 months for at least 3 years after diagnosis. Insufficient evidence exists to recommend routine use of tissue factors such as thymidylate synthase, microsatellite instability (MSI), p53, K-ras and deleted in colon cancer (DCC) for either determining prognosis or predicting response to therapy in patients with CRC. Microsatellite instability, however, may be used as a pre-screen for patients with suspected hereditary non-polyposis colorectal cancer. Faecal occult blood testing but not faecal DNA markers may be used to screen asymptomatic subjects 50 years or older for early CRC.

Estimating cancer risk in HNPCC by the GRL method

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant syndrome caused by germline mutations of the mismatch repair (MMR) genes. Only a few studies have taken into account the selection of families tested for these mutations in estimating colorectal cancer (CRC) risk in carriers. They found much lower estimates of CRC risks than previous ones, but these estimates lacked precision despite the large number of families. The aim of this study was to evaluate the efficiency of the 'genotype restricted likelihood' (GRL) method that provides unbiased estimates of risks whatever the ascertainment process of families, and to estimate CRC and endometrial cancer risk for carriers of the MMR genes. Efficiency of the GRL method was evaluated using simulations. Risks were estimated from a sample of 36 families diagnosed with HNPCC and carrying a mutation of MSH2 or MLH1, ascertained through a cancer family clinic in Lyon (France). The efficiency of the GRL method was found to be strongly dependent on the proportion of family members tested. By age 70 years, CRC risk was estimated at 47% (95% confidence interval: 12-98%) for men and 33% (95% confidence interval: 24-54%) for women. The endometrial cancer risk was only 14% (confidence interval: 6-20%). As methods allowing for the selection of families lack efficiency, large-scale family studies should be undertaken and data should be pooled to provide reliable and precise estimates of risks for an optimal familial management.

Prediction of germline mutations and cancer risk in the Lynch syndrome

CONTEXT

Identifying families at high risk for the Lynch syndrome (ie, hereditary nonpolyposis colorectal cancer) is critical for both genetic counseling and cancer prevention. Current clinical guidelines are effective but limited by applicability and cost.

OBJECTIVE

To develop and validate a genetic counseling and risk prediction tool that estimates the probability of carrying a deleterious mutation in mismatch repair genes MLH1, MSH2, or MSH6 and the probability of developing colorectal or endometrial cancer.

DESIGN, SETTING, AND PATIENTS

External validation of the MMRpro model was conducted on 279 individuals from 226 clinic-based families in the United States, Canada, and Australia (referred between 1993-2005) by comparing model predictions with results of highly sensitive germline mutation detection techniques. MMRpro models the autosomal dominant inheritance of mismatch repair mutations, with parameters based on meta-analyses of the penetrance and prevalence of mutations and of the predictive values of tumor characteristics. The model's prediction is tailored to each individual's detailed family history information on colorectal and endometrial cancer and to tumor characteristics including microsatellite instability.

MAIN OUTCOME MEASURE

Ability of MMRpro to correctly predict mutation carrier status, as measured by operating characteristics, calibration, and overall accuracy.

RESULTS

In the independent validation, MMRpro provided a concordance index of 0.83 (95% confidence interval, 0.78-0.88) and a ratio of observed to predicted cases of 0.94 (95% confidence interval, 0.84-1.05). This results in higher accuracy than existing alternatives and current clinical guidelines.

CONCLUSIONS

MMRpro is a broadly applicable, accurate prediction model that can contribute to current screening and genetic counseling practices in a high-risk population. It is more sensitive and more specific than existing clinical guidelines for identifying individuals who may benefit from MMR germline testing. It is applicable to individuals for whom tumor samples are not available and to individuals in whom germline testing finds no mutation.

DNA Repair Pathway Profiling and Microsatellite Instability in Colorectal Cancer

BACKGROUND

The ability to maintain DNA integrity is a critical cellular function. DNA repair is conducted by distinct pathways of genes, many of which are thought to be altered in colorectal cancer. However, there has been little characterization of these pathways in colorectal cancer.

METHOD

By using the TaqMan real-time quantitative PCR, RNA expression profiling of 20 DNA repair pathway genes was done in matched tumor and normal tissues from 52 patients with Dukes' C colorectal cancer.

RESULTS

The relative mRNA expression level across the 20 DNA repair pathway genes varied considerably, and the individual variability was also quite large, with an 85.4 median fold change in the tumor tissue genes and a 127.2 median fold change in the normal tissue genes. Tumor-normal differential expression was found in 13 of 20 DNA repair pathway genes (only XPA had a lower RNA level in the tumor samples; the other 12 genes had significantly higher tumor levels, all P<0.01). Coordinated expression of ERCC6, HMG1, MSH2, and POLB (RS>or=0.60) was observed in the tumor tissues (all P<0.001). Apoptosis index was not correlated with expression of the 20 DNA repair pathway genes. MLH1 and XRCC1 RNA expression was correlated with microsatellite instability status (P=0.045 and 0.020, respectively). An inverse correlation was found between tumor MLH1 RNA expression and MLH1 DNA methylation (P=0.003).

CONCLUSION

Our study provides an initial characterization of the DNA repair pathways for understanding the cellular DNA damage/repair system in human colorectal cancer.

Psychological impact of genetic testing for cancer susceptibility: an update of the literature

This article presents an overview of the rapidly evolving body of literature on the psychological impact of genetic testing for hereditary breast/ovarian cancer susceptibility, hereditary non-polyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP). Uptake of genetic testing for BRCA1/2 and HNPCC-related mutations is more consistently related to psychological factors, rather than sociodemographic variables. Most studies on the psychological impact of genetic testing amongst individuals who have never been affected by cancer demonstrate that non-carriers derive significant psychological benefits from genetic testing, while no adverse effects have been observed amongst carriers. These benefits are more clear-cut for HNPCC, compared to hereditary breast/ovarian cancer, reflecting differences in risk management options. The few studies available on individuals affected with cancer indicate that the impact of genetic testing is mediated and amplified by their former experience of cancer. Future directions and challenges of research in this area are reviewed. In particular, more empirical data are needed on the broader impact of genetic testing on those with inconclusive results or results of uncertain significance. As genetic testing is becoming available for other types of familial cancer, additional investigations will be needed as there is evidence to suggest that the impact of genetic testing may be unique to each type of familial cancer.

Microsatellite instability and colorectal cancer prognosis

PURPOSE

Many studies have evaluated the role of high levels of microsatellite instability (MSI) as a prognostic marker and predictor of the response to chemotherapy in colorectal cancer (CRC); however, the results are not conclusive. The aim of this study was to analyze the prognostic significance of high levels of MSI (MSI-H) in CRC patients in relation to fluorouracil-based chemotherapy.

EXPERIMENTAL DESIGN

In three different institutions, 1,263 patients with CRC were tested for the presence of MSI, and CRC-specific survival was then analyzed in relation to MSI status, chemotherapy, and other clinical and pathologic variables.

RESULTS

Two hundred and fifty-six tumors were MSI-H (20.3%): these were more frequently at a less advanced stage, right-sided, poorly differentiated, with mucinous phenotype, and expansive growth pattern than microsatellite stable carcinomas. Univariate and multivariate analyses of 5-year-specific survival revealed stage, tumor location, grade of differentiation, MSI, gender, and age as significant prognostic factors. The prognostic advantage of MSI tumors was particularly evident in stages II and III in which chemotherapy did not significantly affect the survival of MSI-H patients. Finally, we analyzed survival in MSI-H patients in relation to the presence of mismatch repair gene mutations. MSI-H patients with hereditary non-polyposis colorectal cancer showed a better prognosis as compared with sporadic MSI-H; however, in multivariate analysis, this difference disappeared.

CONCLUSIONS

The type of genomic instability could influence the prognosis of CRC, in particular in stages II and III. Fluorouracil-based chemotherapy does not seem to improve survival among MSI-H patients. The survival benefit for patients with hereditary non-polyposis colorectal cancer is mainly determined by younger age and less advanced stage as compared with sporadic MSI-H counterpart.

The genetics of HNPCC: application to diagnosis and screening

Hereditary nonpolyposis colorectal cancer syndrome (HNPCC; Lynch Syndrome) is the most common form of hereditary colorectal cancers. Predisposed individuals have increased lifetime risk of developing colorectal, endometrial and other cancers. The syndrome is primarily due to heterozygous germline mutations in one of the mismatch repair genes; mainly MLH1, MSH2, MSH6 and PMS2. The resulting mismatch repair deficiency leads to microsatellite instability which is the hallmark of tumors arising within this syndrome, as well as a variable proportion of sporadic tumors. Diagnostic guidelines and criteria for molecular testing of suspected families have been proposed and are continuously updated. However, not all families fulfilling these criteria show mutations in mismatch repair genes and/or microsatellite instability implicating other, as yet unknown, carcinogenic mechanisms and predisposition genes. This subset of tumors is the focus of current clinical and molecular research. This review addresses recent advances in the field of HNPCC research and their applications in the management of affected individuals and families.

Is colonoscopy sufficient for colorectal cancer surveillance in all HNPCC patients?

A 34-year-old male with hereditary non-polyposis colon cancer with a mutation in hMSH2 line is reported. Despite regular colonoscopic follow-up, he developed cecal cancer involving the extraluminal area. Due to sub-occlusive symptoms, the patient was submitted to further colonoscopy, however with no clear evidence of neoplasia. Thin slice multiplanar reconstruction computed tomography CT scan performed thereafter revealed a transmural mass 2.5 cm in size localized near the cecal valve. Discussion is made on the reliability of colonoscopic examinations as well as the need for further investigations in the follow-up of patients at very high risk of right-sided colon cancer, such as male hMSH2 carrier affected by hereditary non-polyposis colon cancer.

Novel strategy for optimal sequential application of clinical criteria, immunohistochemistry and microsatellite analysis in the diagnosis of hereditary nonpolyposis colorectal cancer

Clinical criteria, microsatellite analysis (MSA) and immunohistochemistry (IHC) are important diagnostic tools for identification of hereditary nonpolyposis colorectal cancer (HNPCC) patients who are likely to carry pathogenic germline mutations in mismatch repair genes. Based on MSA and IHC results and subsequent mutation analyses of 1,119 unrelated index patients meeting the Amsterdam II criteria or the classical Bethesda guidelines, we analyzed the value of these tools to predict MLH1 and MSH2 mutations with the aim of establishing optimal strategies for their most efficient sequential use. The overall prevalence of pathogenic germline mutations in our cohort was 20.6% (95% CI = 18.3-23.0%) and 61.8% (95% CI = 56.8-66.6%), respectively, after MSA/IHC-based preselection. IHC was highly predictive (99.1%) and specific (99.6%) with regard to MSA. However, 14 out of 230 mutations (6%) escaped detection by IHC. Thus, IHC cannot be recommended to substitute MSA fully. Nonetheless, IHC is important to indicate the gene that is likely to be affected. To combine both methods efficiently, we propose a novel screening strategy that provides 2 alternative ways of sequential IHC and MSA application, either using IHC or MSA in the first place. A logistic regression model based on the age of the index patient at first tumor diagnosis and the number of fulfilled HNPCC criteria is used to allocate individual patients to that alternative pathway that is expected to be least expensive. A cost analysis reveals that about 25% of the costs can be saved using this strategy.

Surveillance in Lynch syndrome

The major aim of surveillance in Lynch syndrome is to diagnose malignant or premalignant lesions at the asymptomatic stage by regular checkups, particularly in the large bowel. Therefore, screening for colorectal adenomas and carcinomas by regular colonoscopies is the main topic of the present review. However, it should be remembered, that primary prevention - whether through the use of chemoprevention or the promotion of a healthy life-style may form a significant part of such surveillance in the future. Observational studies indicate that the adenoma carcinoma sequence is the main pathway in the development of colorectal cancer in Lynch syndrome. A colonoscopy every 1-3 years starting at age 20 to 25 years and the removal of observed adenomas is recommended for individuals known to have Lynch syndrome associated mutations. The incidence of colorectal cancer in family branches screened this way is lower than that in past unscreened generations. The screening of other malignancies associated with Lynch syndrome is more complex. Screening for endometrial cancer has recommended previously, but no benefits have been shown in recent studies. The value of screening for other extracolonic cancers remains also uncertain.

Screening and preventive behaviors one year after predictive genetic testing for hereditary nonpolyposis colorectal carcinoma

BACKGROUND

Prevention benefits from predictive genetic testing for cancer will only be fully realized if appropriate screening is adopted after testing. The current study assessed screening and preventive behaviors during 12 months after predictive genetic testing for hereditary nonpolyposis colorectal carcinoma (HNPCC) in an Australian clinical cohort.

METHODS

Participants received predictive genetic testing for HNPCC at one of five Australian familial cancer clinics. Data on self-reported screening behaviors (colonoscopy, and endometrial sampling and transvaginal ultrasound for women) and prophylactic surgery (colectomy, and hysterectomy and bilateral oophorectomy for women) were collected using postal questionnaires before (baseline) and 12 months after receipt of genetic test results. Age, gender, perceived risk of cancer, and cancer-specific distress were assessed as predictors of colonoscopic screening.

RESULTS

In the current study, 114 participants returned baseline questionnaires (32 carriers and 82 noncarriers of an HNPCC mutation). Ninety-eight participants also returned a 12-month follow-up questionnaire. Of those > or = 25 years, 73% reported having had a colonoscopy before genetic testing. At follow-up, 71% (15 of 25) of carriers and 12% (8 of 65) of noncarriers reported having a colonoscopy in the 12 months after receipt of test results. The reduction in colonoscopy among noncarriers was statistically significant (P < 0.001). High perceived risk was associated with colonoscopy at baseline. At follow-up, mutation status was the only variable significantly associated with colonoscopy. Among female mutation carriers, 47% reported having transvaginal ultrasonography and 53% endometrial sampling during follow-up. There was low uptake of prophylactic surgery for colorectal, endometrial, or ovarian carcinomas.

CONCLUSIONS

The majority of individuals reported appropriate screening behaviors after predictive genetic testing for HNPCC. The small group of noncarriers who had screening after genetic testing might benefit from additional counseling.

Hereditary breast cancer syndromes in a Turkish population. Results of molecular germline analysis

Breast cancer is the most common malignancy which affects women. In 5-10% of all cases, breast cancer presents as a hereditary cancer syndrome. Since 1996, 68 families with suspicion of familial breast cancer have been referred to our department. In 5 of the 68 families (7.4%), the clinical diagnosis was hereditary breast ovarian cancer syndrome. In 17 families (25%), two or more breast cancer cases were present. Mutation screening of BRCA1 and BRCA2 in these families revealed a BRCA1 mutation (185delAG) in one family. Three families (4.4%) had a diagnosis of Li-Fraumeni syndrome and germline mutations in TP53 (Lys292Ile, Pro278Ser and Pro278Thr). Breast cancer occurred in a family with hereditary nonpolyposis colon carcinoma (HNPCC; Lynch syndrome) carrying an MLH1 mutation (IVS17-3G>C). Most of our families (41 families; 60.2%) had only one case with breast cancer or cystic adenoma (or both) and did not need counseling and DNA testing. In summary, in 10 of the 68 families in our series (14.7%), a germline mutation in a breast cancer predisposing gene was detected. Our data show the importance of detailed examination of clinical data, pedigree analyses, and molecular germline diagnostics for the counseling of breast cancer cases.

Predictive testing for hereditary nonpolyposis colorectal cancer: subjective perception regarding colorectal and endometrial cancer, distress, and health-related behavior at one year post-test

This study evaluated illness representations, distress, and health-related behavior one year after disclosure of a predictive genetic test result for hereditary nonpolyposis colorectal cancer (HNPCC) in 36 carriers and 36 noncarriers. Post-test, no significant differences between carriers and noncarriers were found in perceived risk and perceived seriousness of colorectal and endometrial cancer or in perceived control over endometrial cancer. Confidence in the controllability of colorectal cancer by means of medical examinations was higher for carriers than noncarriers post-test. Mean levels of distress (cancer-specific distress, state anxiety, psychoneuroticism) were within normal ranges and none of the participants had an overall pattern (on all scales) of clinically elevated levels of distress. Carriers had significantly higher cancer-related distress one year posttest than noncarriers. In both groups, colorectal cancer-related distress decreased. Noncarriers additionally showed decreased endometrial cancer-related distress and state anxiety. Within the year after testing, none of the noncarriers had a colonoscopy and all carriers where adherent to the recommendations regarding colorectal cancer screening. Although interview data delineated individually different problems specifically related to predictive testing (e.g., worry, difficulties in relation to other relatives, burden of regular follow-up), generally, predictive testing for HNPCC does not seem to induce major psychological problems. Moreover, the presented data are promising regarding the impact on health-related behavior.