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Dandapani M, Stoffel EM. CLINICAL MANAGEMENT OF FAMILIES WITH HEREDITARY COLORECTAL CANCER SYNDROMES. SEMINARS IN COLON AND RECTAL SURGERY 2011; 22:100-104. [PMID: 21743786 PMCID: PMC3129991 DOI: 10.1053/j.scrs.2010.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hereditary colorectal cancer syndromes can be associated with a lifetime risk of CRC of >70% in the absence of specialized surveillance. Diagnosing a genetic predisposition to cancer allows clinicians to tailor cancer prevention strategies for patients and families at highest risk. Once a genetic syndrome has been identified in a family, communication with family members, timely implementation of screening tests and/or surgeries, and psychosocial support are all instrumental for effective cancer prevention.Molecular screening of tumors, computerized risk assessment models, and genetic testing can help clinicians identify individuals at risk for hereditary cancer syndromes. This review discusses some of the complexities involved in the diagnosis and management of families with hereditary CRC syndromes and provides strategies for coordinating clinical care.
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Affiliation(s)
- Monica Dandapani
- Cancer Risk and Prevention Clinic, Dana-Farber Cancer Institute, Boston, MA
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204
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Pino MS, Chung DC. Microsatellite instability in the management of colorectal cancer. Expert Rev Gastroenterol Hepatol 2011; 5:385-99. [PMID: 21651356 DOI: 10.1586/egh.11.25] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Microsatellite instability (MSI) is a form of genetic instability caused by alterations in the DNA mismatch repair system. Approximately 15% of colorectal cancers display MSI due to a germline mutation in one of the mismatch repair genes (MLH1, MSH2, MSH6 and PMS2) or to epigenetic silencing of MLH1. Colorectal cancers with MSI have distinctive features, including a tendency to arise in the proximal colon, poor differentiation, lymphocytic infiltration and mucinous or signet-ring histology. Patients with MSI tumors appear to have a better prognosis than those with microsatellite stable tumors, but curiously the responses to 5-fluorouracil-based chemotherapy regimens are poorer with MSI tumors. Preliminary data suggest possible advantages of irinotecan-based regimens, but these findings need validation in well-designed clinical trials.
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Affiliation(s)
- Maria S Pino
- Gastrointestinal Unit, Massachusetts General Hospital, 50 Blossom Street, Boston, MA 02114, USA
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205
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Khoury MJ, Bowen MS, Burke W, Coates RJ, Dowling NF, Evans JP, Reyes M, St Pierre J. Current priorities for public health practice in addressing the role of human genomics in improving population health. Am J Prev Med 2011; 40:486-93. [PMID: 21406285 PMCID: PMC5624316 DOI: 10.1016/j.amepre.2010.12.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 12/09/2010] [Accepted: 12/15/2010] [Indexed: 01/15/2023]
Abstract
In spite of accelerating human genome discoveries in a wide variety of diseases of public health significance, the promise of personalized health care and disease prevention based on genomics has lagged behind. In a time of limited resources, public health agencies must continue to focus on implementing programs that can improve health and prevent disease now. Nevertheless, public health has an important and assertive leadership role in addressing the promise and pitfalls of human genomics for population health. Such efforts are needed not only to implement what is known in genomics to improve health but also to reduce potential harm and create the infrastructure needed to derive health benefits in the future.
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Affiliation(s)
- Muin J Khoury
- Office of Public Health Genomics, CDC, Atlanta, Georgia 30333, USA.
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206
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Gallagher DJ, Smith JD, Offit K, Stadler ZK. Diagnosing hereditary colorectal cancer. Clin Colorectal Cancer 2011; 9:205-11. [PMID: 20920991 DOI: 10.3816/ccc.2010.n.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Although progress in the treatment of patients with colorectal cancer (CRC) has resulted in improved median survival, most patients with metastatic CRC still die of their disease, and essentially all patients with early-stage disease must undergo surgical resection and subsequently face the possibility of adjuvant chemotherapy. As effective screening and prevention strategies for CRC have been developed, identification of individuals with a hereditary predisposition to developing CRC is especially important and provides the opportunity to reduce disease burden in this high-risk population. Increased awareness and improved diagnostic techniques for hereditary CRC syndromes have facilitated more frequent diagnosis and management of a small number of highly penetrant syndromes within families. However, known high-penetrance genetic predisposition syndromes account for a minority of all familial CRC, leaving much of the genetic basis of CRC unexplained. Recent advances in high-throughput genotyping have made possible genome-wide association studies, which have identified novel genetic variants associated with modest increases in CRC risk. While these associations have helped to identify potentially important pathways in CRC carcinogenesis, at the current time, the clinical use of such genetic risk variants in colon cancer risk stratification remains limited.
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Affiliation(s)
- David J Gallagher
- Department of Medicine, Clinical Genetics Service, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
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207
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Power DG, Gloglowski E, Lipkin SM. Clinical genetics of hereditary colorectal cancer. Hematol Oncol Clin North Am 2011; 24:837-59. [PMID: 20816577 DOI: 10.1016/j.hoc.2010.06.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Colorectal cancer (CRC) is a common disease, and approximately 25% of patients have a familial component. High-penetrance singlegene germline mutations conferring a true hereditary susceptibility account for around 5% to 6% of all cases. Lynch syndrome is the most common hereditary form of colorectal cancer. Much of the hereditary component in the remaining familial cases of CRC is likely polygenic, and many of the genetic changes involved are as yet unidentified. This article addresses the most clinically important CRC genetic syndromes.
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Affiliation(s)
- Derek G Power
- Clinical Genetics, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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208
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Hampel H, de la Chapelle A. The search for unaffected individuals with Lynch syndrome: do the ends justify the means? Cancer Prev Res (Phila) 2011; 4:1-5. [PMID: 21205737 PMCID: PMC3076593 DOI: 10.1158/1940-6207.capr-10-0345] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Lynch syndrome is the most common cause of inherited colorectal and endometrial cancers yet it is underrecognized in clinical practice. The relative merits of screening for Lynch syndrome among healthy adults without cancer versus among adults with colorectal or endometrial cancer are discussed in this Perspective article. Newly diagnosed colorectal cancer patients are a much easier target population for screening and this approach leads to more informative genetic test results, at a lower cost in most cases.
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Affiliation(s)
- Heather Hampel
- Division of Human Genetics, Department of Internal Medicine, The Ohio State University Comprehensive Cancer Center, 2001 Polaris Parkway, Columbus, OH 43240, USA.
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209
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Mukherjee A, McGarrity TJ, Ruggiero F, Koltun W, McKenna K, Poritz L, Baker MJ. The revised Bethesda guidelines: extent of utilization in a university hospital medical center with a cancer genetics program. Hered Cancer Clin Pract 2010; 8:9. [PMID: 21092199 PMCID: PMC2997085 DOI: 10.1186/1897-4287-8-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Accepted: 11/22/2010] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND In 1996, the National Cancer Institute hosted an international workshop to develop criteria to identify patients with colorectal cancer who should be offered microsatellite instability (MSI) testing due to an increased risk for Hereditary Nonpolyposis Colorectal Cancer (HNPCC). These criteria were further modified in 2004 and became known as the revised Bethesda Guidelines. Our study aimed to retrospectively evaluate the percentage of patients diagnosed with HNPCC tumors in 2004 who met revised Bethesda criteria for MSI testing, who were referred for genetic counseling within our institution. METHODS All HNPCC tumors diagnosed in 2004 were identified by accessing CoPath, an internal database. Both the Tumor Registry and patients' electronic medical records were accessed to collect all relevant family history information. The list of patients who met at least one of the revised Bethesda criteria, who were candidates for MSI testing, was then cross-referenced with the database of patients referred for genetic counseling within our institution. RESULTS A total of 380 HNPCC-associated tumors were diagnosed at our institution during 2004 of which 41 (10.7%) met at least one of the revised Bethesda criteria. Eight (19.5%) of these patients were referred for cancer genetic counseling of which 2 (25%) were seen by a genetics professional. Ultimately, only 4.9% of patients eligible for MSI testing in 2004 were seen for genetic counseling. CONCLUSION This retrospective study identified a number of barriers, both internal and external, which hindered the identification of individuals with HNPCC, thus limiting the ability to appropriately manage these high risk families.
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Affiliation(s)
- Aparna Mukherjee
- Department of Medicine, Division of Gastroenterology and Hepatology, Penn State Milton S. Hershey Medical Center, Hershey, USA
| | - Thomas J McGarrity
- Department of Medicine, Division of Gastroenterology and Hepatology, Penn State Milton S. Hershey Medical Center, Hershey, USA
| | - Francesca Ruggiero
- Department of Pathology, Penn State Milton S. Hershey Medical Center, Hershey, USA
| | - Walter Koltun
- Department of Surgery, Penn State Milton S. Hershey Medical Center, Hershey, USA
| | - Kevin McKenna
- Department of Surgery, Penn State Milton S. Hershey Medical Center, Hershey, USA
| | - Lisa Poritz
- Department of Surgery, Penn State Milton S. Hershey Medical Center, Hershey, USA
| | - Maria J Baker
- Department of Medicine, Penn State Hershey Cancer Institute, Penn State Milton S. Hershey Medical Center, Hershey, USA
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Dinh TA, Rosner BI, Atwood JC, Boland CR, Syngal S, Vasen HFA, Gruber SB, Burt RW. Health benefits and cost-effectiveness of primary genetic screening for Lynch syndrome in the general population. Cancer Prev Res (Phila) 2010; 4:9-22. [PMID: 21088223 DOI: 10.1158/1940-6207.capr-10-0262] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In current clinical practice, genetic testing to detect Lynch syndrome mutations ideally begins with diagnostic testing of an individual affected with cancer before offering predictive testing to at-risk relatives. An alternative strategy that warrants exploration involves screening unaffected individuals via demographic and family histories, and offering genetic testing to those individuals whose risks for carrying a mutation exceed a selected threshold. Whether this approach would improve health outcomes in a manner that is cost-effective relative to current standards of care has yet to be demonstrated. To do so, we developed a simulation framework that integrated models of colorectal and endometrial cancers with a 5-generation family history model to predict health and economic outcomes of 20 primary screening strategies (at a wide range of compliance levels) aimed at detecting individuals with mismatch repair gene mutations and their at-risk relatives. These strategies were characterized by (i) different screening ages for starting risk assessment and (ii) different risk thresholds above which to implement genetic testing. For each strategy, 100,000 simulated individuals, representative of the U.S. population, were followed from the age of 20, and the outcomes were compared with current practice. Findings indicated that risk assessment starting at ages 25, 30, or 35, followed by genetic testing of those with mutation risks exceeding 5%, reduced colorectal and endometrial cancer incidence in mutation carriers by approximately 12.4% and 8.8%, respectively. For a population of 100,000 individuals containing 392 mutation carriers, this strategy increased quality-adjusted life-years (QALY) by approximately 135 with an average cost-effectiveness ratio of $26,000 per QALY. The cost-effectiveness of screening for mismatch repair gene mutations is comparable to that of accepted cancer screening activities in the general population such as colorectal cancer screening, cervical cancer screening, and breast cancer screening. These results suggest that primary screening of individuals for mismatch repair gene mutations, starting with risk assessment between the ages of 25 and 35, followed by genetic testing of those whose risk exceeds 5%, is a strategy that could improve health outcomes in a cost-effective manner relative to current practice.
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Affiliation(s)
- Tuan A Dinh
- Archimedes, Inc, San Francisco, California, USA
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211
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Stoffel EM, Chittenden A. Genetic testing for hereditary colorectal cancer: challenges in identifying, counseling, and managing high-risk patients. Gastroenterology 2010; 139:1436-41, 1441.e1. [PMID: 20858494 DOI: 10.1053/j.gastro.2010.09.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Affiliation(s)
- Elena M Stoffel
- Cancer Risk and Prevention Clinic, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
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Rogowski WH, Grosse SD, John J, Kääriäinen H, Kent A, Kristofferson U, Schmidtke J. Points to consider in assessing and appraising predictive genetic tests. J Community Genet 2010; 1:185-94. [PMID: 22460301 DOI: 10.1007/s12687-010-0028-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 10/01/2010] [Indexed: 10/18/2022] Open
Abstract
The use of predictive genetic tests is expanding rapidly. Given limited health care budgets and few national coverage decisions specifically for genetic tests, evidence of benefits and harms is a key requirement in decision making; however, assessing the benefits and harms of genetic tests raises a number of challenging issues. Frequently, evidence of medical benefits and harms is limited due to practical and ethical limitations of conducting meaningful clinical trials. Also, clinical endpoints frequently do not capture the benefit appropriately because the main purpose of many genetic tests is personal utility of knowing the test results, and costs of the tests and counseling can be insufficient indicators of the total costs of care. This study provides an overview of points to consider for the assessment of benefits and harms from genetic tests in an ethically and economically reflected manner. We discuss whether genetic tests are sufficiently exceptional to warrant exceptional methods for assessment and appraisal.
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Affiliation(s)
- Wolf H Rogowski
- Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany,
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213
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Guarinos C, Castillejo A, Barberá VM, Pérez-Carbonell L, Sánchez-Heras AB, Segura A, Guillén-Ponce C, Martínez-Cantó A, Castillejo MI, Egoavil CM, Jover R, Payá A, Alenda C, Soto JL. EPCAM germ line deletions as causes of Lynch syndrome in Spanish patients. J Mol Diagn 2010; 12:765-70. [PMID: 20864635 DOI: 10.2353/jmoldx.2010.100039] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The standard genetic test for Lynch syndrome (LS) frequently reveals an absence of pathogenic mutations in DNA mismatch repair genes known to be associated with LS. It was recently shown that germ line deletions in the last exons of EPCAM are involved in the etiology of LS. The aim of this study was to evaluate the prevalence of EPCAM deletions in a Spanish population and the clinical implications of deletion. Probands from 501 families suspected of having LS were enrolled in the study. Twenty-five cases with MSH2 loss were identified: 10 had mutations of MSH2, five had mutations of MSH6, and 10 did not show MSH2/MSH6 mutations. These 25 cases were analyzed for EPCAM deletions using multiplex ligation-dependent probe amplification, and deletions were mapped using long-range PCR analysis. One subject with no MSH2/MSH6 mutations had a large deletion in the EPCAM locus that extended for 8.7 kb and included exons 8 and 9. The tumor exhibited MSH2 promoter hypermethylation. EPCAM deletion analysis followed by MSH2 methylation testing of the tumor is a fast low-cost procedure that can be used to identify mutations that cause LS. We propose that this procedure be incorporated into clinical genetic analysis strategies and present a decision-support flow diagram for the diagnosis of LS.
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Affiliation(s)
- Carla Guarinos
- Molecular Oncology Group, Elche University Hospital, Camino Almazara 11, 03203 Elche, Spain
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