Genetic testing for colon cancer: joint statement of the American College of Medical Genetics and American Society of Human Genetics. Joint Test and Technology Transfer Committee Working Group

Contrast-Enhanced CT Texture Analysis in Colon Cancer: Correlation with Genetic Markers

Background: The purpose of the study was to determine whether contrast-enhanced CT texture features relate to, and can predict, the presence of specific genetic mutations involved in CRC carcinogenesis. Materials and methods: This retrospective study analyzed the pre-operative CT in the venous phase of patients with CRC, who underwent testing for mutations in the KRAS, NRAS, BRAF, and MSI genes. Using a specific software based on CT images of each patient, for each slice including the tumor a region of interest was manually drawn along the margin, obtaining the volume of interest. A total of 56 texture parameters were extracted that were compared between the wild-type gene group and the mutated gene group. A p-value of <0.05 was considered statistically significant. Results: The study included 47 patients with stage III-IV CRC. Statistically significant differences between the MSS group and the MSI group were found in four parameters: GLRLM RLNU (area under the curve (AUC) 0.72, sensitivity (SE) 77.8%, specificity (SP) 65.8%), GLZLM SZHGE (AUC 0.79, SE 88.9%, SP 65.8%), GLZLM GLNU (AUC 0.74, SE 88.9%, SP 60.5%), and GLZLM ZLNU (AUC 0.77, SE 88.9%, SP 65.8%). Conclusions: The findings support the potential role of the CT texture analysis in detecting MSI in CRC based on pre-treatment CT scans.

Identification of Lynch syndrome risk variants in the Romanian population

Two familial forms of colorectal cancer (CRC), Lynch syndrome (LS) and familial adenomatous polyposis (FAP), are caused by rare mutations in DNA mismatch repair genes (MLH1, MSH2, MSH6, PMS2) and the genes APC and MUTYH, respectively. No information is available on the presence of high-risk CRC mutations in the Romanian population. We performed whole-genome sequencing of 61 Romanian CRC cases with a family history of cancer and/or early onset of disease, focusing the analysis on candidate variants in the LS and FAP genes. The frequencies of all candidate variants were assessed in a cohort of 688 CRC cases and 4567 controls. Immunohistochemical (IHC) staining for MLH1, MSH2, MSH6, and PMS2 was performed on tumour tissue. We identified 11 candidate variants in 11 cases; six variants in MLH1, one in MSH6, one in PMS2, and three in APC. Combining information on the predicted impact of the variants on the proteins, IHC results and previous reports, we found three novel pathogenic variants (MLH1:p.Lys84ThrfsTer4, MLH1:p.Ala586CysfsTer7, PMS2:p.Arg211ThrfsTer38), and two novel variants that are unlikely to be pathogenic. Also, we confirmed three previously published pathogenic LS variants and suggest to reclassify a previously reported variant of uncertain significance to pathogenic (MLH1:c.1559-1G>C).

Facteurs génétiques à prendre en considération dans le cadre de l'examen gynécologique annuel

OBJECTIF

Offrir aux médecins un survol des troubles génétiques courants qui devraient être pris en considération dans le cadre de l'examen gynécologique annuel d'une patiente, et ce, afin de déterminer le risque que court celle-ci ou d'en venir à procéder à des examens particuliers ou à orienter la patiente vers un autre service de sous-spécialité, en fonction de ses antécédents personnels ou familiaux.

OPTIONS

Ces renseignements d'ordre génétique peuvent être utilisés aux fins de la sensibilisation des patientes et du dépistage ou du diagnostic de possibles maladies et/ou mutations.

ISSUES

L'utilisation de ces renseignements d'ordre génétique pourrait mener à l'amélioration de l'évaluation des risques et des avantages et à celle de la prise en charge dans le cadre de l'examen gynécologique annuel. RéSULTATS: Les études publiées en anglais, jusques et y compris en mai 2010, ont été récupérées par l'intermédiaire de recherches menées dans PubMed et la Cochrane Library au moyen d'un vocabulaire contrôlé (« gynaecological diagnosis », « genetic inheritance ») et de mots clés (« genetic risk », « genetic mutation », « inheritance », « family history », « uterus », « ovary », « endometrial », « vagina », « colon », « gastric », « renal », « breast », « cardiac », « thrombophilia », « diabetes », « epilepsy », « leiomyomata uteri ») appropriés. D'autres sources ont été identifiées par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales.

VALEURS

Le niveau des résultats ne permet pas la formulation de recommandations factuelles. AVANTAGES, DéSAVANTAGES ET COûTS: La présente opinion de comité améliorera l'utilisation de nouvelles connaissances génétiques et leur application aux soins gynécologiques offerts annuellement aux femmes. Les occasions de gestion du risque et de diagnostic, pour ce qui est des troubles gynécologiques génétiques, s'en trouveront améliorées. Une compréhension plus exhaustive des troubles génétiques pourrait entraîner une hausse de l'anxiété et du stress psychologique chez les femmes et les membres de leur famille.

COMMANDITAIRE

Société des obstétriciens et gynécologues du Canada.

RECOMMANDATIONS

Le niveau des résultats ne permet pas la formulation de recommandations factuelles.

Guidelines on genetic evaluation and management of Lynch syndrome: a consensus statement by the US Multi-Society Task Force on colorectal cancer

The Multi-Society Task Force, in collaboration with invited experts, developed guidelines to assist health care providers with the appropriate provision of genetic testing and management of patients at risk for and affected with Lynch syndrome as follows: Figure 1 provides a colorectal cancer risk assessment tool to screen individuals in the office or endoscopy setting; Figure 2 illustrates a strategy for universal screening for Lynch syndrome by tumor testing of patients diagnosed with colorectal cancer; Figures 3-6 provide algorithms for genetic evaluation of affected and at-risk family members of pedigrees with Lynch syndrome; Table 10 provides guidelines for screening at-risk and affected persons with Lynch syndrome; and Table 12 lists the guidelines for the management of patients with Lynch syndrome. A detailed explanation of Lynch syndrome and the methodology utilized to derive these guidelines, as well as an explanation of, and supporting literature for, these guidelines are provided.

Guidelines on genetic evaluation and management of Lynch syndrome: a consensus statement by the US Multi-society Task Force on colorectal cancer

The Multi-Society Task Force, in collaboration with invited experts, developed guidelines to assist health care providers with the appropriate provision of genetic testing and management of patients at risk for and affected with Lynch syndrome as follows: Figure 1 provides a colorectal cancer risk assessment tool to screen individuals in the office or endoscopy setting; Figure 2 illustrates a strategy for universal screening for Lynch syndrome by tumor testing of patients diagnosed with colorectal cancer; Figures 3,4,5,6 provide algorithms for genetic evaluation of affected and at-risk family members of pedigrees with Lynch syndrome; Table 10 provides guidelines for screening at-risk and affected persons with Lynch syndrome; and Table 12 lists the guidelines for the management of patients with Lynch syndrome. A detailed explanation of Lynch syndrome and the methodology utilized to derive these guidelines, as well as an explanation of, and supporting literature for, these guidelines are provided.

Familial colorectal cancer, beyond Lynch syndrome

Although 30% of individuals diagnosed with colorectal cancer (CRC) report a family history of the disease, only 5% to 6% carry germline mutations in genes associated with known hereditary cancer syndromes. The evaluation and management of families affected with CRC can be complicated by variability in disease phenotypes and limited sensitivity of genetic tests. In this review, we examine what is currently known about familial CRC and what we have yet to learn, and explore how novel genomic approaches might be used to identify additional genetic and epigenetic factors implicated in heritable risk for cancer.

Genetic considerations for a woman's annual gynaecological examination

OBJECTIVE

To provide the physician with an overview of common genetic conditions that should be considered during a women's annual gynaecological assessment to determine the patient's risk or to initiate specific testing or referral to another subspecialty service, depending on personal or family history.

OPTIONS

This genetic information can be used for patient education and possible disease and/or mutation screening or diagnosis.

OUTCOMES

The use of this genetic information may allow improved risk-benefit assessment and management at the annual gynaecological examination.

EVIDENCE

Studies published in English up to and including May 2010 were retrieved through searches of PubMed and the Cochrane Library, using appropriate controlled vocabulary (gynaecological diagnosis, genetic inheritance) and key words (genetic risk, genetic mutation, inheritance, family history, uterus, ovary, endometrial, vagina, colon, gastric, renal, breast, cardiac, thrombophilia, diabetes, epilepsy, leiomyomata uteri). Other literature sources were identified through searching the web sites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The levels of evidence are not adequate for evidence-based recommendations to be made.

BENEFITS, HARMS, AND COSTS

This committee opinion will enhance the use of new genetic knowledge and its application to the annual gynaecological care of women. Risk management and diagnostic opportunities for genetic gynaecological conditions will be improved. A more complete understanding of genetic conditions may increase anxiety and psychological stress for women and their families.

SPONSORS

Society of Obstetricians and Gynaecologists of Canada.

RECOMMENDATIONS

The levels of evidence are not adequate for evidence-based recommendations to be made.

Colorectal carcinoma: why is there a lower incidence in Nigerians when compared to Caucasians?

Carcinoma of the colon and rectum is the 2nd commonest cancer in the United States; the leading cancer being lung cancer. It has been estimated that 130,200 new cases of colorectal cancer will be diagnosed annually while 56,300 sufferers will die from the disease (Murphy et al., 2000). In developing countries especially West Africa, the rate has not yet reached such magnitude. This suggests that there may be factors either anthropomorphic or environmental which may be responsible for this. The paper acknowledges the reduced incidence of colorectal cancer in native West Africans living in Africa and endeavours to highlight the various factors that produce this observation in medical literature. A diligent search through available literature on the aetiology, epidemiology and comparative anthropology of colorectal cancer was done. Internet search using PubMed, British Library Online and Google Scholar was also utilized. The rarity of adenomatous polyposis syndromes in the native West African contributes to the reduced incidence of colorectal cancer. Cancer prevention and cancer-protective factors are deemed to lie in the starchy, high-fiber, spicy, peppery foodstuff low in animal protein which many West African nations consume.

Inherited colorectal cancer syndromes

Colorectal cancer is common in the Western world; ~5% of individuals diagnosed with colorectal cancer have an identifiable inherited genetic predisposition to this malignancy. Genetic testing and rational clinical management recommendations currently exist for the management of individuals with a variety of colorectal cancer syndromes, including hereditary nonpolyposis colorectal cancer (HNPCC, also known as Lynch syndrome), familial adenomatous polyposis (FAP), MYH-associated polyposis (MAP), and the hamartomatous polyposis syndromes (Peutz-Jeghers, juvenile polyposis, and Cowden disease). In addition to colorectal neoplasia, these syndromes frequently predispose carriers to a variety of extracolonic cancers. The elucidation of the genetic basis of several colorectal cancer predisposition syndromes over the past two decades has allowed for better management of individuals who are either affected with, or at-risk for inherited colorectal cancer syndromes. Appropriate multidisciplinary management of these individuals includes genetic counseling, genetic testing, clinical screening, and treatment recommendations.

Scoping the family history: assessment of Lynch syndrome (hereditary nonpolyposis colorectal cancer) in primary care settings--a primer for nurse practitioners

PURPOSE

To describe and discuss the characteristic features and red flags of Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer, that warrants referral for genetic cancer risk assessment (GCRA). A focus on the nurse practitioner's (NP) role in familial risk assessment, physical examination, initiation of genetic referrals, and issues related to the genetic counseling process are also discussed.

DATA SOURCES

A review and synopsis of professional guidelines, clinical articles, and research studies on Lynch syndrome and the genetics of inherited cancer syndromes associated with colorectal cancer. Online resources from the American Gastroenterological Association, American Medical Association, the American Nurses Association, the National Comprehensive Cancer Network, the National Cancer Institute, the National Cancer Institute-Physician Data Query, the National Coalition of Health Professional Education in Genetics, the National Human Genome Research Institute, the National Society of Genetic Counselors, International Society of Nurses in Genetics, and the Oncology Nursing Society.

CONCLUSIONS

Approximately 5% of all colon cancers are because of a germ line mutation predisposing individuals and their family members to colorectal and other cancers. Although the efficacy of screening modalities is established, healthcare providers often fail to identify those at greatest risk for disease. The extended family history is the first step in recognition of individuals "suspect" for hereditary colon cancers such as Lynch syndrome. Early-age onset of Lynch syndrome-associated cancers, an autosomal-dominant pattern, multiple primary tumors in an individual or multiple family members with Lynch syndrome-associated cancers, characteristic pathological features of colon cancer, or a known germ line Lynch syndrome mutation in a family member are "red flags" that will aid NPs in identifying individuals who may benefit from GCRA. IMPLICATIONS FOR NURSE PRACTITIONER PRACTICE: The importance of enhanced surveillance for early diagnosis and prevention of disease is a critical part of primary care. Thus, it is imperative that NPs obtain a minimum of a three-generation pedigree, recognize hereditary cancer patterns, and provide referral counseling for consideration of genetic testing of individuals suspect for Lynch syndrome.

Mentoring nurses in familial cancer risk assessment and counseling: lessons learned from a formative evaluation

BACKGROUND

As familial cancer genetic services moves into community practice increased numbers of trained health professionals are needed to counsel individuals seeking cancer risk information. Nurses have been targeted to provide cancer risk assessment and counseling. To help prepare nurses for this role, a 5-day training in familial cancer risk assessment and counseling followed by a long-distance mentorship to support continued skill development in the work environment was conducted by Fox Chase Cancer Center, Philadelphia, PA.

METHODS

Four cohorts (N = 41) have completed the training and were randomized to either an immediate or delayed mentorship. A formative evaluation assessed the nurse's ability to consult with other genetic health professionals and build self-efficacy in counseling skills via responses to questionnaire. A post-mentorship interview evaluated the usefulness, timing and length of the mentorship.

RESULTS

For both groups, there was a statistically significant improvement in self-efficacy for all skills from baseline to 6 months and an increased number of nurses consulting with genetic health professionals. All the nurses reported the value of the mentorship and those with less cancer risk counseling experience prior to the training needed support and resources for further skill and program development. Lessons learned from this formative evaluation are provided.

Clinical Implications of Our Advancing Knowledge of Colorectal Cancer Genetics: Inherited Syndromes, Prognosis, Prevention, Screening and Therapeutics

Recent genetic advances in our knowledge of colorectal cancer genetics are beginning to pay translational dividends in the management of this common clinical problem. We are now able to accurately screen and counsel individuals at risk of rare inherited cancer syndromes. We have recently introduced two of what are sure to be numerous biologic-based therapies, and have shown that colorectal neoplasia risk can be modestly reduced by various chemopreventative agents. Finally, our advancing knowledge has led to significant inroads into understanding what genetic alterations define prognosis and predict response to specific chemotherapeutic agents, and we are beginning to explore the utility of this knowledge in mass genetic-based clinical screening efforts. Enthusiasm must be tempered, however, by the extraordinary cost that often accompanies relatively modest gains. Finally, although genetic-based therapy often receives the greatest attention, molecular genetics, will likely have the greatest cost-effective impact in primary prevention and early diagnosis.

Referral and experience with genetic testing among women with early onset breast cancer

The purpose of this study was to determine whether physicians refer women with early onset breast cancer for genetic testing for BRCA1 and BRCA2, and how women respond to being offered testing and use the results. A web-based survey was distributed to 1221 women with early onset breast cancer. The survey included 158 questions divided into the following sections: demographics, family history of cancer, medical history, treatment history, and experience with genetic testing. Of 551 women diagnosed since 1993 who responded to the survey (45.1%), less than half (45%, n = 246) had ever discussed genetic testing with their physician and/or been referred to see a genetic counselor. Women with a family history of cancer (53%) and Ashkenazi Jewish women (81%) were more likely to have been referred. Of those who had discussed testing, 60% had undergone or were interested in testing. Overall 92 women were tested and 19 (20.6%) of these tested positive for a deleterious BRCA1 or BRCA2 mutation. Fourteen (74%) who tested positive subsequently underwent prophylactic surgery. Satisfaction with counseling and the decision to be tested was high. Among women who were not offered testing, the fact that the test had not been offered by their physician (89%), and fear of discrimination (83%) were the two most frequently cited factors for lack of interest in testing. A substantial number of women are not being referred to genetic counseling and/or testing after a diagnosis of early onset breast cancer. Among those who were tested, there was high interest in prophylactic surgery after confirmation of a BRCA1/2 mutation.

Endoscopic management of familial colonic neoplasia

Heredity plays an important causative role in a large percentage of colorectal cancers. Clinical recognition of the hereditary polyposis syndromes, hereditary nonpolyposis colorectal cancer, and common familial colorectal cancer is essential because screening, surveillance, and treatment among affected individuals and their family members differs from that recommended for the general population. More intensive cancer screening and surveillance is required if premature death is to be avoided. Genetic testing is commercially available for most of the hereditary colorectal cancer syndromes and can greatly facilitate the management of patients if properly undertaken.

New directions in cytogenetic and molecular testing of the neonate

The development of new diagnostic, and hence therapeutic possibilities, has brought the realization that genetic disease is now an integral part of medical practice. Advances in cytogenetic and molecular testing have drastically improved the ability to diagnose with certainty many previously unrecognized conditions. However, this advance in technology does not come without new questions. New tests are not always the most cost effective ones, some have significant diagnostic limitations, and others raise valid ethical issues surrounding the testing of minors. A working understanding of new advances in genetic diagnosis as well as their inherent limitations is crucial for the contemporary practitioner.

Awareness of genetic testing for increased cancer risk in the year 2000 National Health Interview Survey

OBJECTIVES

This study explores factors associated with differential awareness of genetic tests for increased cancer risk in the US.

METHODS

27,405 respondents from the 2000 National Health Interview Survey, ages 25+, were asked if they had heard of these tests.

RESULTS

44.4% said 'yes', including 49.9% of whites, 32.9% of African-Americans, 32.3% of American Indians/Alaskan Natives, 28.0% of Asian/Pacific Islanders, and 20.6% of Hispanics. In multivariate analysis, test awareness was significantly associated with higher education, white race, age <60 years, female gender, private health insurance, personal or parent's history of certain cancers, physical activity, and vitamin/supplement use, among other factors.

CONCLUSIONS

The survey showed which population subgroups may lack access to cancer genetics information and may therefore benefit from targeted strategies to ensure risk-appropriate utilization of genetic counseling and testing.

Basic concepts for genetic testing in common hereditary colorectal cancer syndromes

Approximately 5% of colorectal cancers are associated with one of the autosomal dominant hereditary cancer syndromes. The two most common familial colon cancer syndromes are familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). The causative mutation can be identified in many families with these syndromes by genetic testing of an affected individual. If an affected individual tests positive for a disease-causing mutation, genetic testing of unaffected, at-risk family members can be performed to determine whether they have inherited the cancer-susceptibility mutation, and a personalized cancer surveillance strategy can be devised. Genetic testing significantly enhances cancer risk assessment in these families. However, the complicated nature of result interpretation and the emotional impact of the result necessitate that testing be carried out in conjunction with patient education and informed consent by a physician who has a keen appreciation for the inherent challenges. This article describes the genetic testing strategy in HNPCC and FAP.