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1.
About 5-10% of the most common cancers, such as breast, colon and melanoma, result from mutations in inherited predisposition genes. Recently some of these genes have been mapped or even cloned. These advances in cancer genetics have made more precise genetic counseling possible for cancer patients and their families. In our clinic for specific genetic counseling 180 families with a history of cancer were seen during a 10-month period. In counseling sessions, the family history was confirmed and interpreted, personal risk was estimated and the availability of molecular genetic testing was presented. Blood samples for DNA testing were drawn from those with certain criteria who wished to be tested. Instructions for early detection were also given, depending on the personal risk of cancer as compared to that of the general population.  相似文献   

2.
PURPOSE: To assess attitudes toward testing for cancer susceptibility genes, we interviewed mothers of pediatric oncology patients about their cancer causation theories, interest in hypothetical predisposition testing for themselves and their healthy children, and anticipated impact of testing. PATIENTS AND METHODS: The subjects were 47 mothers of two or more living children, one of whom was 6 to 24 months postdiagnosis of cancer. Potential risks and benefits of hypothetical genetic predisposition testing for cancer susceptibility were described. A semistructured interview assessed the following: (1) recall of discussions with the pediatric oncologist about the possible role of heredity in causing the child's cancer; (2) mothers' personal theories of the etiology of their child's cancer; (3) family cancer history; (4) interest in genetic predisposition testing for themselves and unaffected (cancer-free) children; and (5) expected sequelae of testing. RESULTS: If genetic cancer predisposition tests were available, 51% of mothers would test themselves and 42% would test healthy children, even with no medical benefit. With established medical benefit, an additional 36% of mothers would seek testing for themselves and another 49% would test their healthy children. Interest in cancer predisposition testing among mothers extended far beyond those with significant family histories of cancer. Most mothers would consider minor children's wishes in the decision about testing and would tell children under age 18 their test results. CONCLUSION: As increasing numbers of cancer susceptibility genes are identified, parents of pediatric oncology patients may be receptive to opportunities to test themselves and their healthy children. Counseling will be important to aid in decisions about testing. Research is essential to evaluate the long-term impact of predisposition testing.  相似文献   

3.
A significant proportion of all cancers is inherited or develops in genetically susceptible individuals. An updated overview and tabulations are given on inherited cancer, including the monogenic cancer syndromes, cancer caused mainly by predisposition in heterozygous carriers for autosomal recessive syndromes, and the same of different types of cancers occurring in families exhibiting irregular autosomal dominant inheritance. Environmental factors act in concert with genetically susceptible genes to cause cancer. A mechanism for the initiation and progression of cancer on the cellular level is outlined. The identification of an ever-increasing number of cancer-susceptible genes enables the development of new genetic tests. Some advantages and problems associated with predictive genetic testing for cancer are discussed.  相似文献   

4.
Genetic diagnosis of hereditary tumors has progressed extensively and contributed to the presymptomatic testing for mutation carriers. This evolution of genetic testing for cancer susceptibility leads to improved prevention and early detection of cancers. However, the benefits and limits of testing, and the range of prevention and treatment are different in each hereditary tumor. The American Society of Clinical Oncology (ASCO) made the statement on genetic testing for cancer susceptibility and showed three categories for consideration of cancer predisposition testing. They recommend that genetic testing should be offered only for the categories including well-defined tumors. We described the characteristics of hereditary tumors in the three categories and discussed the significance of genetic testing for each tumor. In conclusion, genetic testing for cancer susceptibility should be applied only for subsets of hereditary syndromes, and it is important to continue the analysis of the significance (frequency or penetrance) of mutations of cancer predisposition genes and to make clear the genotype-phenotype and other correlations.  相似文献   

5.
Five to ten percent of cases of breast cancer and colorectal cancer are familial. These families can be divided into high-risk families and moderate-risk families. Cancer in high-risk families can often be explained by dominant inheritance of a gene causing increased susceptibility to cancer. There is a great demand for genetic counseling in these families, and the structure of and experiences from a familial cancer clinic at Odense University Hospital is described. The establishment of a familial cancer clinic involves three steps: 1) Identification of families with increased cancer susceptibility; 2) Molecular tests to identify gene carriers; 3) Clinical examinations for early detection of tumors. Achievement of these three steps requires the involvement of several medical specialties to ensure patient care. Experience with familial cancer clinics is still limited and the involvement of genetic testing and clinical examination programs at risk individuals are insufficiently examined. The rapidly improving techniques for genetic testing make it urgent that it is implemented as part of already established clinical programs.  相似文献   

6.
If genetic testing for breast and ovarian cancer predisposition is to become available within a public health care system there needs to be a rational and cost-effective approach to mutation analysis. We have screened for BRCA1 mutations in 230 women with breast cancer, all from the Wessex region of southern England, in order to establish the parameters on which to base a cost-effective regional mutation analysis strategy. Truncating mutations were detected in 10/155 (6.5%) consecutive cases selected only for diagnosis under the age of 40 (nine of these ten women had a strong family history of breast or ovarian cancer), 3/61 (4.9%) bilateral-breast cancer cases (all three mutations occurring among women for whom the first cancer was diagnosed under 40 years) and 8/30 (26.6%) breast cancer cases presenting to the genetics clinic (for whom a strong family history of breast and/or ovarian cancer was present). Ten different mutations were detected in 17 families, but three of these accounted for 10/17 (59%) of the families. The cost of screening the population for mutations in the entire BRCA1 gene is unacceptably high. However, the cost of screening a carefully selected patient cohort is low, the risk of misinterpretation much less and the potential clinical benefits clearer.  相似文献   

7.
Breast cancer is in 5% of cases due to a genetic disposition. BRCA1 and BRCA2 are by far the most common breast cancer susceptibility genes. For a woman with a genetic predisposition, the individual risk of developing breast cancer sometime in her life is between 70 and 90%. Compared to the spontaneous forms of breast cancer, woman with a genetic predisposition often develop breast cancer at a much younger age. This is why conventional screening programs on the basis of mammography alone cannot be applied without modification to this high-risk group. In this article, an integrated screening concept for women with genetic predisposition for breast cancer using breast self-examination, clinical examination, ultrasound, mammography and magnetic resonance imaging is introduced.  相似文献   

8.
Germline mutations of the cancer susceptibility genes BRCA1 and BRCA2 seem to lead to a very high risk for breast and/or ovarian cancer. Therefore, genetic counselling and identification of high-risk families may be essential to offer the opportunity to participate in a specific early cancer detection program and to provide individualized psychological support. In a two year period (August 1994-August 1997) 304 consultees present for genetic counselling at the interdisciplinary cancer genetic clinic (Department of Obstetrics & Gynecology and Human Genetics, Heinrich-Heine-Universit?t, Düsseldorf). For genetic testing a BRCA1/2 mutation detection strategy including protein truncation test (PTT), single strand conformation polymorphism (SSCP), and direct DNA sequencing is used. 161 families fulfilled the inclusion criteria; at present, 72 families for whom complete analytical material is available are analyzed. Although genetic testing for BRCA1 and BRCA2 is technically challenging, women with a family history of multiple sporadic breast/ovarian cancers and those with a hereditary BRCA1 and BRCA2 gene defect may be distinguished. For the first group of consultees this may ease their concern, for the second group preventive measures including an early cancer detection or prevention program, psychological support or prophylactic surgery may be discussed.  相似文献   

9.
BACKGROUND: Familial juvenile polyposis (JP) is an autosomal dominant condition in which affected individuals develop upper or lower gastrointestinal (GI) juvenile polyps, or both, and have a predisposition to cancer of the gastrointestinal tract. The risk of GI cancer has not been well defined because of the small number of these families and the lack of follow-up. The objective of this study was to determine the prevalence and age at diagnosis of GI polyposis and cancer in a large JP kindred. METHODS: Medical records were reviewed, patients were interviewed, and histories were taken. Pathology reports and slides were reviewed by our pathologists. A database was created for analysis of clinical and pathologic factors. RESULTS: This kindred contains 117 members, 29 of whom have had upper or lower GI polyps or cancer, or both. All those affected have had colonic juvenile polyps or cancer, except for two who died of advanced gastric cancer and never had colonic evaluation. Nine individuals have had both upper and lower GI polyps or cancer. Sixteen of 29 (55%) affected patients have developed gastrointestinal cancer. Eleven (38%) have had colon cancer, and six (21%) have had upper GI cancers. CONCLUSIONS: The risk of gastrointestinal malignancy in affected members of this JP kindred exceeds 50%. The high risk of GI cancer warrants frequent endoscopic screening of both affected and at-risk family members. Screening will soon be facilitated by presymptomatic genetic testing for the identification of gene carriers.  相似文献   

10.
The discovery of major cancer susceptibility genes is likely to create strong pressures for clinical testing from biotechnology companies, insurance carriers, the medical community, and the public. However, before genetic testing for cancer predisposition is made widely available, we must identify the optimum strategies to enhance informed decision making, minimize adverse psychologic consequences, and promote adherence to recommended surveillance. This report provides an overview of behavioral research in these areas and, on the basis of this literature, presents suggestions for developing effective and ethical genetic testing protocols.  相似文献   

11.
PURPOSE: To identify members of hereditary breast and ovarian cancer families who are at risk for adverse psychologic effects of genetic testing. PATIENTS AND METHODS: A prospective cohort study with baseline (preeducation) assessments of predictor variables (ie, sociodemographic factors, cancer history, and cancer-related stress symptoms) was performed. The primary outcome variable (presence of depressive symptoms) was assessed at baseline and at 1- and 6-month follow-up evaluations. Participants were 327 adult male and female members of BRCA1- and BRCA2-linked hereditary breast and ovarian cancer families, who were identified as carriers, noncarriers, or decliners of genetic testing. RESULTS: The presence of cancer-related stress symptoms at baseline was strongly predictive of the onset of depressive symptoms in family members who were invited but declined testing. Among persons who reported high baseline levels of stress, depression rates in decliners increased from 26% at baseline to 47% at 1-month follow-up; depression rates in noncarriers decreased and in carriers showed no change (odds ratio [OR] for decliners v noncarriers=8.0; 95% confidence interval [CI], 1.9 to 33.5; P=.0004). These significant differences in depression rates were still evident at the 6-month follow-up evaluation (P=.04). CONCLUSION: In BRCA1/2-linked families, persons with high levels of cancer-related stress who decline genetic testing may be at risk for depression. These family members may benefit from education and counseling, even if they ultimately elect not to be tested, and should be monitored for potential adverse effects.  相似文献   

12.
PURPOSE: A family history of melanoma is a significant risk factor for the disease, and recently several loci that determine susceptibility to the development of melanoma have been identified. The most important of these is p16/CDKN2A. We attempted to determine the degree to which the p16/CDKN2A gene has been implicated in the development of melanoma, and to identify other genetic factors that play a role as well. METHODS: We reviewed the literature published since the isolation of p16/CDKN2A and identified 13 studies that report the status of the gene in melanoma samples and 12 reports that examine p16/CDKN2A in melanoma kindreds. We also reviewed associated studies on CDK4 and RB1 involvement in melanoma, and examined the role of p16/CDKN2A in other inherited cancers. RESULTS: The evidence strongly implicates p16/CDKN2A in determining predisposition to malignant melanoma. Overall, approximately 20% of families that have been studied show mutations in the gene. However, because of clustering of sporadic cases in families, and potentially because of technical factors, this is likely an underestimate of the proportion of the genetic predisposition for melanoma that is due to p16/CDKN2A mutation. Rare families carry a mutated CDK4 gene that is also responsible for inherited melanoma. CONCLUSION: The gene p16/CDKN2A is an important determinant of melanoma risk. A commercial test is presently available to assess the status of this locus. However, because of uncertainties regarding the interpretation of the results of p16/CDKN2A genetic testing, we do not recommend routine clinical use of this test at this time.  相似文献   

13.
Women from families with multiple breast and/or ovarian cancers may be at increased risk to develop breast/ovarian cancer themselves. Due to personal experience with family members having these diseases they are anxious and ask for specific prophylactic measurements or treatment. The detection of two susceptibility genes, BRCA1 and BRCA2, has given insight into the genetic background of part of the familial breast/ovarian cancer syndromes. This has led to an increased demand in genetic counselling, testing, and early cancer detection programmes. Prospective data from early cancer detection programmes in this high risk population are yet not available. Based on data from epidemiological risk studies, breast and ovarian screening programmes and follow up data from breast cancer trials recommendations for an early cancer detection programme have been summarized. At the present these recommendations are tested in a prospective trial.  相似文献   

14.
Genetic diagnosis of hereditary nonpolyposis colorectal cancer (HNPCC) may have a significant impact on the clinical management of patients and their at-risk relatives. At present, clinical criteria represent the simplest and most useful method for the identification of HNPCC families and for the selection of candidates for genetic testing. However, reports of mismatch repair (MMR) gene mutations in families not fulfilling the minimal diagnostic criteria point out the necessity to identify additional clinical parameters suggestive of genetic predisposition to colorectal cancer (CRC) related to MMR defects. We thus investigated a series of 32 Italian putative HNPCC individuals selected on the basis of one of the following criteria: 1) family history of CRC and/or other extracolonic tumors; 2) early-onset CRC; and 3) presence of multiple primary malignancies in the same individual. These patients were investigated for the presence of MLH1 and MSH2 mutations by single-strand conformation polymorphism analysis. Pathogenetic truncating mutations were identified in 4 (12.5%) cases, 3 of them involving MSH2 and 1 MLH1. In addition, 2 missense MLH1 variants of uncertain significance were observed. All pathogenetic mutations were associated with early age (<40 years) at onset and proximal CRC location. Our results support the contention that constitutional MMR mutations can also occur in individuals without the classical HNPCC pattern. Moreover, evaluation of the clinical parameters associated with MMR mutations indicates that early onset combined with CRC location in the proximal colon can be definitely considered suggestive of MMR-related hereditary CRC and should be included among the guidelines for referring patients for genetic testing.  相似文献   

15.
The presence of benign proliferative lesions is a risk factor for the development of cancer. However, only a subset of individuals presenting with benign lesions goes on to develop cancer. It is a major challenge of cancer research to identify those individuals at increased risk for this neoplastic progression. It has been suggested that individuals with inherent genomic instability may have a predisposition for cancer development. The hypothesis is presented that this genetic instability could be quantified through the analysis of apoptosis in biopsies of benign lesions. It is further conjectured that genetic damage-dependent apoptosis might serve as a prognostic indicator to identify individuals at increased risk for cancer.  相似文献   

16.
The explosive progress that has been made in cancer genetics in the past few years has given rise to new hope. These promising discoveries have also given rise to considerable uncertainty and debate concerning how this knowledge should be applied and who should have ownership of its products and effects. The medical, psychological, social, legal, and ethical implications of genetic testing for cancer, specifically breast and ovarian cancers, are discussed. The ethical principles of confidentiality, justice, beneficence, and autonomy as they relate to cancer predisposition testing also are explored. Recommendations are made for nursing practice, education, and research.  相似文献   

17.
Epithelial ovarian cancer is known to aggregate in families. The dominantly inherited ovarian cancer predisposing genes, BRCA1, BRCA2 and genes involved in the hereditary non-polyposis colorectal cancer (HNPCC) syndrome, have recently been identified. However, in the majority of families with more than one case of ovarian cancer, dominant inheritance cannot be recognized. We investigated familial clustering of epithelial ovarian cancer in a population-based sample of 663 Finnish ovarian cancer patients. A segregation analysis with the POINTER software was conducted on the 937 nuclear families from these 663 pedigrees. The major gene model was favoured, and the sporadic and multifactorial models were strongly rejected. In the studied population, the best fitting model was a recessive mode of inheritance, and 8% of ovarian cancer patients were estimated to be homozygous for the deleterious genotype. This evidence for recessively inherited ovarian cancer predisposition should be interpreted cautiously, as the analysis is subject to certain errors, which are discussed in the article. Results of this analysis, however, strongly emphasize the role of genetic factors in all familial aggregation of epithelial ovarian cancer.  相似文献   

18.
The recent identification of BRCA1, a breast cancer susceptibility gene, offers an unprecedented opportunity for high-risk individuals to learn whether they are genetically predisposed to develop breast or ovarian cancer. This study examined the relationships between psychological distress and use of BRCA1 testing by 149 high-risk individuals from hereditary cancer families. After a baseline assessment of demographics, objective risk, cancer-specific distress, and global distress (depressive symptoms), study participants were offered the opportunity to receive genetic counseling and to learn whether they carry a mutation in the BRCA1 gene. Overall, 58% of study participants requested BRCA1 test results, and 42% declined to learn their genetic status. After controlling for demographic factors and risk status, cancer-specific distress was significantly and positively related to BRCA1 test use, whereas global distress was unrelated to test use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
Research in molecular genetics has led to the identification of a growing number of disease-predisposing genes. With increasing commercial pressures and public interest in genetic testing, genetic tests are likely to become an integral part of routine medical care. Awareness of genetic risk can facilitate informed medical decision making and, in some cases, can promote risk reduction behaviors that have the potential to reduce morbidity and mortality. Despite these potential medical benefits, there are serious concerns about the psychosocial sequelae of an individual learning that he or she carries an elevated risk for disease. This special issue of Health Psychology is devoted to research that seeks to provide an empirical foundation for the understanding of the psychosocial aspects of genetic testing for disease predisposition. The introduction to the special issue provides a brief overview of patterns of inheritance and genetic testing. This overview is followed by a consideration of the unique features of genetic information that make it different from other types of health threats studied by health psychologists. Finally, this author summarizes the organization of the issue, highlighting key study findings and suggesting future directions for this new field of research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
Most familial breast or ovarian cancers are thought to be due to highly penetrant mutations in the predisposing genes BRCA1 and BRCA2. The cloning of these genes has opened a new era for the genetic counseling of women with a family history of breast or ovarian cancer. To estimate the incidence of detectable BRCA1 mutations and to define the eligibility criteria for genetic testing in the Italian population, a total of 53 patients belonging to 46 families clustering multiple cases of breast and/or ovarian cancer were investigated. Seven families presented with ovarian cancer only, 16 had both ovarian and breast cancers, and 23 were characterized by breast cancer only. Using a combination of protein truncation test (PTT) and single strand conformational polymorphism (SSCP) analysis followed, when necessary, by direct sequencing, we found 8 distinct mutations, 2 of these not reported before. Five frameshift and 2 nonsense mutations led to a truncated protein. One mutation was a missense substitution involving a cysteine in the zinc finger domain. One variant creating an ETS binding site in intron I was found but its role was not defined. The percentage of families carrying mutations was 17%. Among the families characterized by ovarian cancer only and by breast and ovarian cancer, the percentage of BRCA1 mutations was 57% and 12.5%, respectively. In contrast, the percentage of altered BRCA1 in families with only breast cancers was 9%. In the 46 Italian families studied, BRCA1 mutations were detected in fewer kindreds than those previously hypothesized based on linkage analysis, especially when these were characterized by breast cancers only. Our results indicate that families with a low number of cancer patients should be referred for BRCA1 genetic testing mainly when ovarian cancer is present.  相似文献   

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