The benefits of a model of interval comprehensive assessments (MICA) in hereditary cancer Syndromes: Hereditary diffuse gastric cancer (HDGC) as an example.

A high percentage of individuals at risk for hereditary cancer syndromes are unaware of their risk. This is especially detrimental in syndromes such as hereditary diffuse gastric cancer due to a CDH1 germline mutation, for which lifesaving prevention is possible. Surveillance for diffuse gastric cancer in the syndrome is limited, hence the recommendation for prophylactic total gastrectomy for mutation carriers. Genetic counseling and testing is crucial in suspected families but initial contact could be limited, leading to the importance of an interval comprehensive review every 5-8 years to identify and screen additional high-risk individuals. Our contact with a hereditary diffuse gastric cancer family in Jordan in 2011 led to a number of family members receiving education and genetic counseling. Our model of interval comprehensive assessment (MICA) was constructed and implemented by conducting family information service, video call and emails to the high-risk individuals 7 years after initial contact. Using an updated family pedigree we reached out to an additional thirteen high-risk members in six different countries and provided them with genetic education, counseling, and testing. Six members agreed to CDH1 testing (46%). Four tested positive (66%) and one member (25%) underwent prophylactic total gastrectomy.

Analysis of the CDKN2A Gene in FAMMM Syndrome Families Reveals Early Age of Onset for Additional Syndromic Cancers.

Familial atypical multiple mole melanoma (FAMMM) syndrome is a hereditary cancer syndrome that results from mutations in several genes, including the CDKN2A gene. In addition to melanoma, certain other malignancies such as pancreatic cancer are known to occur more frequently in family members who carry the mutation. However, as these families have been followed over time, additional cancers have been observed in both carriers and noncarriers. We sought to determine whether these additional cancers occur at higher frequencies in carriers than noncarriers. We performed survival analyses using 10 FAMMM syndrome families (N = 1,085 individuals) as well as a mixed effects Cox regression, with age at last visit to the clinic or age at cancer diagnosis as our time variable. This analysis was done separately for the known FAMMM-related cancers and "other" cancer groups. The survival curves showed a significant age effect with carriers having a younger age at cancer onset than noncarriers for FAMMM-related cancers (as expected) as well as for newly associated cancers. The Cox regression reflected what was seen in the survival curves, with all models being highly significant (P = 7.15E-20 and P = 5.00E-13 for the FAMMM-related and other cancers, respectively). These analyses support the hypothesis that CDKN2A mutation carriers in FAMMM syndrome families have increased risk for early onset of several cancer types beyond the known cancers. Therefore, these individuals should be screened for additional cancers, and mutation screening should be extended to more than first-degree relatives of an index carrier patient. SIGNIFICANCE: This study shows that carriers of mutations in the CDKN2A gene in FAMMM syndrome are at increased risk for early onset of several cancer types beyond the known cancers.

Phenotypic and genotypic heterogeneity of Lynch syndrome: a complex diagnostic challenge.

Lynch syndrome is the hereditary disorder that most frequently predisposes to colorectal cancer as well as predisposing to a number of extracolonic cancers, most prominently endometrial cancer. It is caused by germline mutations in the mismatch repair genes. Both its phenotype and genotype show marked heterogeneity. This review gives a historical overview of the syndrome, its heterogeneity, its genomic landscape, and its implications for complex diagnosis, genetic counseling and putative implications for immunotherapy.

Major hereditary gastrointestinal cancer syndromes: a narrative review.

Gastrointestinal cancer is one of the major causes of death worldwide. Hereditary gastrointestinal cancer syndromes constitute about 5-10% of all cancers. About 20-25% of undiagnosed cases have a possible hereditary component, which is not yet established. In the last few decades, the advance in genomics has led to the discovery of multiple cancer predisposition genes in gastrointestinal cancer. Physicians should be aware of these syndromes to identify high-risk patients and offer genetic testing to prevent cancer death. In this review, we describe clinical manifestations, genetic testing and its challenges, diagnosis and management of the major hereditary gastrointestinal cancer syndromes.

Commentary on Almassalha et al., "The Greater Genomic Landscape: The Heterogeneous Evolution of Cancer".

In this issue of Cancer Research, Almassalha and colleagues have proposed a new concept of the development of malignancy, that of the greater genomic landscape. They propose a stressor-related exploration of intracellular genomic sites as a response mechanism. This process can express sites with beneficial or deleterious effects, among them those that promote cell proliferation. They point out that their conception is broader, although certainly inclusive, of the process of gene induction. The authors view the physical process of chromatin reorganization as central to the exploration of the genomic landscape. Accordingly, they advocate the development of agents to limit chromatin structural modification as a chemotherapeutic approach in cancer. We found their theory relevant to understand the phenotypic heterogeneity of malignancy, particularly in familial cancer syndromes. For example, the familial atypical multiple mole melanoma (FAMMM) syndrome, related to a gene mutation, is characterized by a diversity of melanocytic lesions, only some of which become malignant melanoma. This new conceptualization can do much to increase understanding of the diversity of malignancy in families with hereditary cancer. Cancer Res; 76(19); 5602-4. ©2016 AACR.

Familial atypical multiple mole melanoma (FAMMM) syndrome: history, genetics, and heterogeneity.

Approximately 5-10 % of cutaneous melanoma occurs in kindreds with a hereditary predisposition. Mutations in the CDKN2A gene are found to occur in approximately 20-40 % of these kindreds. The first historical mention of what is now called the familial atypical multiple mole melanoma syndrome appears to be from 1820, with more reports throughout the 1950s, 1960s, and later years. In 1991, Lynch and Fusaro described an association between familial multiple mole melanoma and pancreatic cancer and work continues to elucidate the syndrome's genotypic and phenotypic heterogeneity. Individuals at risk for familial melanoma need periodic screenings. Unfortunately, adequate screening for pancreatic cancer does not currently exist, but pancreatic cancer's prominence in the hereditary setting will hopefully act as a stimulus for development of novel screening measures.

Screening for familial and hereditary prostate cancer.

Prostate cancer (PC) has the highest degree of genetic transmission of any form of malignancy. In some families, the hereditary pattern is so strong as to mimic an autosomal dominance trait. We reviewed the known predisposing genetic markers to assess possible strategies for screening of families at risk. We carried out a systematic literature search using the Pubmed service of the National Center for Biotechnology Information (NCBI) and several gene libraries, including the NCBI SNP Library, the Online Mendelian Inheritance in Man® Catalog of Human Genes and Genetic Disorders (OMIM) and SNPedia to obtain known gene loci, SNPs and satellite markers associated with PC. We further cross referenced information on identified loci comparing data from different articles and gene reference sites. Whenever possible, we recorded the odds ratio (OR) for the allele associated with PC. In multiple different linkage studies, many independent PC associated loci have been identified on separate chromosomes. Genome-wide association studies have added many more markers to the set derived from linkage investigations. A subset of the alleles is associated with early onset and aggressive cancer. Due to the great heterogeneity, the OR for any one allele predicting future development of this malignancy is low. The strongest predictors are the BRCA2 mutations, and the highly penetrant G84E mutation in HOXB13. The presence of multiple risk alleles is more highly predictive than a single allele. Technical limitations on screening large panels of alleles are being overcome. It is appropriate to begin supplementing prostate specific antigen testing with alleles, such as BRCA2 and HOXB13, disclosed by targeted genomic analysis in families with an unfavorable family cancer history. Future population studies of PC should include genomic sequencing protocols, particularly in families with a history of PC and other malignancies.

Milestones of Lynch syndrome: 1895-2015.

Lynch syndrome, which is now recognized as the most common hereditary colorectal cancer condition, is characterized by the predisposition to a spectrum of cancers, primarily colorectal cancer and endometrial cancer. We chronicle over a century of discoveries that revolutionized the diagnosis and clinical management of Lynch syndrome, beginning in 1895 with Warthin's observations of familial cancer clusters, through the clinical era led by Lynch and the genetic era heralded by the discovery of causative mutations in mismatch repair (MMR) genes, to ongoing challenges.

Practical genetics of colorectal cancer.

Hereditary colorectal cancer (CRC) is highly heterogeneous, both genotypically and phenotypically. The most frequently occurring hereditary colorectal cancer syndrome is Lynch syndrome, accounting for approximately 3% of the total colorectal cancer burden. Polyposis syndromes, such as familial adenomatous polyposis, account for a lesser percentage. Familial colorectal cancer, defined by family history, occurs in an estimated 20% of all colorectal cancer cases. With a worldwide annual colorectal cancer incidence of over one million, and annual mortality of over 600,000, hereditary and familial forms of colorectal cancer are a major public health problem. Lynch syndrome is attributable to DNA mismatch repair germline mutations, with the MSH2, MLH1, MSH6, and PMS2 genes being implicated. The characteristics of Lynch syndrome-associated colorectal tumors, including early age of onset and predilection to the proximal colon, mandate surveillance by colonoscopy beginning by age 20 to 25 and repeated every other year through age 40 and annually thereafter. Besides colorectal cancer, Lynch syndrome also predisposes to a litany of extracolonic cancers, foremost of which is endometrial cancer, followed by cancer of the ovary, stomach, renal pelvis and ureter, small bowel, hepatobiliary tract, pancreas, glioblastoma multiforme in the Turcot's variant, and sebaceous skin tumors in the Muir-Torre variant and, more recently identified, cancers of the breast and prostate. The most common polyposis syndrome is familial adenomatous polyposis, caused by mutations in the APC gene. Affected individuals have multiple colonic adenomas and, without treatment invariably develop colorectal cancer. Colonic surveillance with polypectomy may be pursued until the appearance of multiple colonic adenomas, at which time prophylactic colectomy should be considered. Extra-intestinal manifestations include desmoid tumor, hepatoblastoma, thyroid carcinoma, and medulloblastoma. Other polyposis syndromes include the hamartomatous polyp syndromes, including juvenile polyposis syndrome, Peutz-Jeghers syndrome, Cowden syndrome, and Bannayan-Ruvalcaba-Riley syndrome.

Hereditary gastrointestinal cancer syndromes.

The rapid growth of molecular genetics and its attendant germline mutation discoveries has enabled identification of persons who are at an inordinately high cancer risk and, therefore, ideal candidates for prevention. However, one must fully appreciate the extensive genotypic and phenotypic heterogeneity that exists in hereditary cancer. Once the causative germline mutation has been identified in a patient, high-risk members of the family can be similarly tested and identified and provided highly targeted surveillance and management opportunities. DNA testing can change the individual's presumed risk status and affect decision making by patients and their physicians regarding surveillance and management. Our purpose is to describe familial/hereditary cancers of the gastrointestinal tract, including familial Barrett's esophagus, hereditary diffuse gastric cancer, gastrointestinal stromal tumors, familial adenomatous polyposis and desmoid tumors, Lynch syndrome, small bowel cancer, and familial pancreatic cancer. We use our discussion of Lynch syndrome as a model for diagnostic and clinical translation strategies for all hereditary gastrointestinal tract cancers, which clearly can then be extended to cancer of all anatomic sites. Highly pertinent questions from the patient's perspective include the following: What kind of counseling will be provided to a patient with a Lynch syndrome mutation, and should that counseling be mandatory? Does the proband have the responsibility to inform relatives about the familial mutation, even if the relatives do not want to know whether they carry it? Is the patient is responsible for notifying family members that a parent or sibling has Lynch syndrome? Can notification be forced and, if so, under what circumstances? These questions point out the need for criteria regarding which family members to inform and how to inform them.

Phenotypic and genotypic heterogeneity in the Lynch syndrome: diagnostic, surveillance and management implications.

Lynch syndrome is the most common form of hereditary colorectal cancer (CRC). This review covers the cardinal features of Lynch syndrome with particular emphasis upon its diagnostic criteria, molecular genetics, natural history, genetic counseling, surveillance and management. Considerable attention has been given to the etiologic role of mismatch repair (MMR) genes as well as low penetrance alleles and modifier genes. The American founder mutation, a deletion of exons 1-6 of MSH2, is discussed in some detail, owing to its high frequency in the US (19 000-30 000 carriers). Genetic counseling is essential prior to patients' undergoing DNA testing and again when receiving their test results. Families with a lower incidence of CRC and extracolonic cancers, in the face of being positive for Amsterdam I criteria but who do not have MMR deficiency by tumor testing, are probably not Lynch syndrome, and thereby should preferably be designated as familial CRC of undetermined type. Patients who are either noncompliant or poorly compliant with colonoscopy, and who are MMR mutation positive, may be candidates for prophylactic colectomy, while MMR mutation-positive women who are noncompliant with gynecologic surveillance may be candidates for prophylactic hysterectomy and bilateral salpingo-oophorectomy.

Inherited predisposition to cancer: a historical overview.

The hereditary predisposition to cancer dates historically to interest piqued by physicians as well as family members wherein striking phenotypic features were shown to cluster in families, inclusive of the rather grotesque cutaneous findings in von Recklinghausen's neurofibromatosis, which date back to the sixteenth century. The search for the role of primary genetic factors was heralded by studies at the infrahuman level, particularly on laboratory mouse strains with strong susceptibility to carcinogen-induced cancer, and conversely, with resistance to the same carcinogens. These studies, developed in the 19th and 20th centuries, continue today. This article traces the historical aspects of hereditary cancer dealing with identification and ultimate molecular genetic confirmation of commonly occurring cancers, particularly of the colon in the case of familial adenomatous polyposis and its attenuated form, both due to the APC germline mutation; the Lynch syndrome due to mutations in mismatch repair genes, the most common of which were found to be MSH2, MLH1, and MSH6 germline mutations; the hereditary breast-ovarian cancer syndrome with BRCA1 and BRCA2 germline mutations; the Li-Fraumeni (SBLA) syndrome due to the p53 mutation; and the familial atypical multiple mole melanoma in association with pancreatic cancer due to the CDKN2A (p16) germline mutation. These and other hereditary cancer syndromes have been discussed in some detail relevant to their characterization, which, for many conditions, took place in the late 18th century and, in the more modern molecular genetic era, during the past two decades. Emphasis has been placed upon the manner in which improved cancer control will emanate from these discoveries.

Challenging colonic polyposis pedigrees: differential diagnosis, surveillance, and management concerns.

Hereditary polyposis syndromes show extensive phenotypic and genotypic heterogeneity within and among families, a situation that may hinder diagnosis. In these settings, germline mutation testing may be the sine qua non for diagnosis if such a mutation is identified in a patient or family. We provide examples of phenotypically differing polyposis pedigrees depicting various challenges in hereditary polyposis syndrome diagnosis. Our purpose is to augment physician understanding of phenotypic variation and thus help identify high-risk presymptomatic family members who could benefit from highly targeted surveillance and management strategies. We describe nine familial polyposis pedigrees displaying anecdotal clinical problems that can confound the differential diagnosis. Emphasis was given to a multidisciplinary approach focusing on pathological confirmation with respect to number, histology, and location of polyps in the gastrointestinal tract; a detailed family history of cancer at all anatomic sites; noncancer phenotypic features of hereditary polyposis syndromes; and appropriate molecular genetic testing in concert with genetic counseling. Improved physician understanding of the clinical natural history features, genetic transmission patterns, and appropriate gene testing will help in diagnosis and, ultimately, surveillance and management for the various hereditary polyposis syndromes.

Hereditary nonpolyposis colorectal carcinoma (HNPCC) and HNPCC-like families: Problems in diagnosis, surveillance, and management.

BACKGROUND: To the authors' knowledge, hereditary nonpolyposis colorectal carcinoma (HNPCC) is the most commonly occurring hereditary disorder that predisposes to colorectal carcinoma (CRC), accounting for approximately 2-7% of all CRC cases diagnosed in the U.S each year. Its diagnosis is wholly dependent on a meticulously obtained family history of cancer of all anatomic sites, with particular attention to the pattern of cancer distribution within the family. METHODS: The objective of the current study was to illustrate various vexing problems that can deter the diagnosis of HNPCC and, ultimately, its management. This was an observational cohort study. Sixteen HNPCC and HNPCC-like families were selected from a large resource of highly extended HNPCC families. High-risk patients were selected from these HNPCC families. An ascertainment bias was imposed by the lack of a population-based data set. Personal interviews and questionnaires were used for data collection. RESULTS: There was an array of difficulties highlighted by limitations in compliance, lack of a clinical or molecular basis for an HNPCC diagnosis, ambiguous DNA findings, problems in genetic counseling, failure to meet Amsterdam or Bethesda criteria, small families, lack of medical and pathologic documentation, poor cooperation of family members and/or their physicians, cultural barriers, economic stress, frequent patient fear and anxiety, perception of insurance discrimination, and limited patient and/or physician knowledge regarding hereditary cancer. CONCLUSIONS: The diagnosis and management of HNPCC is predicated on physician knowledge of its phenotypic and genotypic heterogeneity, in concert with the multifaceted problems that impact on patient compliance.