FAP, gastric cancer, and genetic counseling featuring children and young adults: a family study and review

Systemic Chemotherapies Retain Antitumor Activity in Desmoid Tumors Independent of Specific Mutations in CTNNB1 or APC: A Multi-institutional Retrospective Study

PURPOSE

Determine whether specific CTNNB1 or APC mutations in patients with desmoid tumor were associated with differences in clinical responses to systemic treatments.

EXPERIMENTAL DESIGN

We established a multi-institutional dataset of previously treated patients with desmoid tumor across four U.S. sarcoma centers, including demographic and clinicopathologic characteristics, treatment regimens, and clinical and radiographic responses. CTNNB1 or APC mutation status was determined from prior pathology records, or archival tissue was requested and analyzed by Sanger sequencing and/or next-generation sequencing. Evaluable patients with mutation results were analyzed to determine clinical progression-free survival (cPFS), RECIST 1.1 PFS (rPFS), time to next treatment (TTNT), and overall survival (OS). Kaplan-Meier analysis and Cox proportional hazards regression were performed to identify differences in cPFS, rPFS, TTNT, and OS by mutation subtype, desmoid tumor location, and treatment regimen.

RESULTS

A total of 259 evaluable patients were analyzed for at least one of the survival outcomes, with 177 patients having mutation data. First- and second-line cPFS, rPFS, and TTNT were not significantly affected by mutation subtype; however, APC-mutant desmoid tumors demonstrated nonstatistically significant inferior outcomes. Extremity/trunk desmoid tumor location and treatment with doxorubicin-based, methotrexate/vinca alkaloids and sorafenib regimens were associated with better clinical outcomes compared with surgery or "other" therapies, including estrogen-receptor blockade and imatinib. OS was significantly worse with APC or CTNNB1 negative/other mutations.

CONCLUSIONS

Mutation subtype did not affect responses to specific systemic therapies. APC mutations and nonextremity desmoid tumor locations remain prognostic for worse outcomes, and earlier initiation of systemic therapy for these higher-risk desmoid tumors should be prospectively evaluated. See related commentary by Greene and Van Tine, p. 3911.

A multicenter study assessing the prevalence of germline genetic alterations in Chinese gastric-cancer patients

Background

Approximately 10% of patients with gastric cancer (GC) have a genetic predisposition toward the disease. However, there is scant knowledge regarding germline mutations in predisposing genes in the Chinese GC population. This study aimed to determine the spectrum and distribution of predisposing gene mutations among Chinese GC patients known to have hereditary high-risk factors for cancer.

Methods

A total of 40 GC patients from 40 families were recruited from seven medical institutions in China. Next-generation sequencing was performed on 171 genes associated with cancer predisposition. For probands carrying pathogenic/likely pathogenic germline variants, Sanger sequencing was applied to validate the variants in the probands as well as their relatives.

Results

According to sequencing results, 25.0% (10/40) of the patients carried a combined total of 10 pathogenic or likely pathogenic germline variants involving nine different genes: CDH1 (n = 1), MLH1 (n = 1), MSH2 (n = 1), CHEK2 (n = 1), BLM (n = 1), EXT2 (n = 1), PALB2 (n = 1), ERCC2 (n = 1), and SPINK1 (n = 2). In addition, 129 variants of uncertain significance were identified in 27 patients.

Conclusions

This study indicates that approximately one in every four Chinese GC patients with hereditary high risk factors may harbor pathogenic/likely pathogenic germline alterations in cancer-susceptibility genes. The results further indicate a unique genetic background for GC among Chinese patients.

Helping young children understand inherited cancer predisposition syndromes using bibliotherapy

Communication with children about hereditary conditions in the family can be difficult for parents. Yet, good communication strategies are leading determinants of adaptation and resilience. With inherited cancer predisposition syndromes that can affect young children such as Li-Fraumeni syndrome (LFS) and hereditary pheochromocytoma and paraganglioma syndrome (HPPS), genetic testing and subsequent surveillance in at-risk children is the optimal intervention. Given testing often commences early, providing children and their parents with appropriate genetic counseling and communication strategies is important for informed decision making. To inform such communication strategies, we used a bibliotherapeutic framework, where stories are delivered prescriptively (i.e., 'bibliotherapy'), to develop a psycho-educational resource for children aged 5-10 years old at risk of either LFS or HPPS. Illustrated storybooks for children were created based on models of developmental comprehension. To ascertain their experience, parents were invited to read a storybook to their child/ren and participate in semi-structured qualitative interviews. Transcripts were analyzed thematically using a general inductive approach. The bibliotherapeutic resource reportedly supported parents with communication about these issues without raising emotional distress in either themselves or their children. The key stages of a bibliotherapeutic interaction were facilitated by the use of this resource, and all parents reported that it would have been useful when their children were first tested and/or diagnosed. This study lays the foundation for the application of bibliotherapy as a psycho-educational intervention in genetic counseling and demonstrates that bibliotherapy may improve the process of communication between parents and children regarding pediatric-inherited cancer syndromes.

[Hereditary colon cancer in Lynch syndrome/HNPCC syndrome in Germany]

BACKGROUND

Hereditary nonpolyposis colorectal cancer (Lynch/HNPCC syndrome) is based on a germline mutation inducing increased occurrence of colorectal cancer and extracolonic carcinomas in young age. The German HNPCC consortium aims to increase awareness for detection of hereditary colon cancer among patients and physicians.

OBJECTIVES

Reliable detection of HNPCC patients is based on a thorough documentation of patients' medical history and on further diagnostics delivered by human genetics and surgical pathology. This manuscript presents a standardized diagnostic concept.

METHODS

Relevant literature is reviewed and discussed and diagnostic parameters are outlined. In addition, operating figures of the German HNPCC consortium are presented.

RESULTS

The German HNPCC consortium is based on an efficient cooperation between clinical physicians, human geneticists, and surgical pathologists. After a funding period from the Deutsche Krebshilfe, HNPCC diagnostics and preventive medical examinations were transferred into standard care in Germany. In total, 5770 families (8873 patients) were included in HNPCC diagnostics. To date, in 1296 families, mutations of the MLH1-, MSH2-, MSH6-, PMS2-, or EPCAM-gene have been detected. Furthermore, 612 pathogenic variants and 325 variants of unknown significance were found.

CONCLUSIONS

Reliable detection of HNPCC patients is based on a standardized diagnostic concept, which has been established within the German HNPCC consortium.

Congenital Hypertrophy of Retinal Pigment Epithelium for Diagnosis of Familial Adenomatous Polyposis - the First FAP registry in Iran

Objective: Familial adenomatous polyposis (FAP), an autosomal dominant inherited disorder is characterized by the presence of multiple adenomatous colorectal polyps, which can develop into cancer during early adulthood. Therefore, early diagnosis is essential. Most FAP patients have several extracolonic manifestations, including congenital hypertrophy of the retinal pigment epithelium (CHRPE). Whereas genetic markers may provide the main route to detection of ‘‘at risk’’ subjects , at present this approach is clearly limited and searches for a noninvasive phenotypic marker continue to be high priority.The aim of this study was to describe the pattern of distribution of CHRPE lesions and evaluate their diagnostic value in FAP patients and their family members in a local population. Methods: A total of 23 FAP patients and 26 relatives belonging to 12 families at high risk of developing FAP were subjected to colonoscopic and ophthalmological examination. Result: Retinal examinations demonstrated prevalences of CHRPE in FAP patents and their siblings of 78% and 38%, respectively. We were able to illustrate a significant correlation between FAP disease and the presence of retinal lesions. Sensitivity and specificity of CHRPE as a screening test to detect the presence of FAP are 78.3% and 61.5%, respectively, with a positive predictive value of 64.3% and a negative predictive value of 76.2 %. A “lesion form” significant difference was found between FAP and normal participants.Spearman nonparametric analysis revealed no correlation between age and number or size of lesions. Conclusion: Multiple CHRPE lesions are a diagnostic feature of FAP patients They are specific and sensitive clinical markers of this disease (specificity 60% and sensitivity 77%).

Histopathological, Molecular, and Genetic Profile of Hereditary Diffuse Gastric Cancer: Current Knowledge and Challenges for the Future

Familial clustering is seen in 10 % of gastric cancer cases and approximately 1-3 % of gastric cancer arises in the setting of hereditary diffuse gastric cancer (HDGC). In families with HDGC, gastric cancer presents at young age. HDGC is predominantly caused by germline mutations in CDH1 and in a minority by mutations in other genes, including CTNNA1. Early stage HDGC is characterized by a few, up to dozens of intramucosal foci of signet ring cell carcinoma and its precursor lesions. These include in situ signet ring cell carcinoma and pagetoid spread of signet ring cells. Advanced HDGC presents as poorly cohesive/diffuse type carcinoma, normally with very few typical signet ring cells, and has a poor prognosis. Currently, it is unknown which factors drive the progression towards aggressive disease, but it is clear that most intramucosal lesions will not have such progression.Immunohistochemical profile of early and advanced HDGC is often characterized by abnormal E-cadherin immunoexpression, including absent or reduced membranous expression, as well as "dotted" or cytoplasmic expression. However, membranous expression of E-cadherin does not exclude HDGC. Intramucosal HDGC (pT1a) presents with an "indolent" phenotype, characterized by typical signet ring cells without immunoexpression of Ki-67 and p53, while advanced carcinomas (pT > 1) display an "aggressive" phenotype with pleomorphic cells, that are immunoreactive for Ki-67 and p53. These features show that the IHC profile is different between intramucosal and more advanced HDGC, providing evidence of phenotypic heterogeneity, and may help to define predictive biomarkers of progression from indolent to aggressive, widely invasive carcinomas.

Hereditary diffuse gastric cancer: updated clinical guidelines with an emphasis on germline CDH1 mutation carriers

Germline CDH1 mutations confer a high lifetime risk of developing diffuse gastric (DGC) and lobular breast cancer (LBC). A multidisciplinary workshop was organised to discuss genetic testing, surgery, surveillance strategies, pathology reporting and the patient's perspective on multiple aspects, including diet post gastrectomy. The updated guidelines include revised CDH1 testing criteria (taking into account first-degree and second-degree relatives): (1) families with two or more patients with gastric cancer at any age, one confirmed DGC; (2) individuals with DGC before the age of 40 and (3) families with diagnoses of both DGC and LBC (one diagnosis before the age of 50). Additionally, CDH1 testing could be considered in patients with bilateral or familial LBC before the age of 50, patients with DGC and cleft lip/palate, and those with precursor lesions for signet ring cell carcinoma. Given the high mortality associated with invasive disease, prophylactic total gastrectomy at a centre of expertise is advised for individuals with pathogenic CDH1 mutations. Breast cancer surveillance with annual breast MRI starting at age 30 for women with a CDH1 mutation is recommended. Standardised endoscopic surveillance in experienced centres is recommended for those opting not to have gastrectomy at the current time, those with CDH1 variants of uncertain significance and those that fulfil hereditary DGC criteria without germline CDH1 mutations. Expert histopathological confirmation of (early) signet ring cell carcinoma is recommended. The impact of gastrectomy and mastectomy should not be underestimated; these can have severe consequences on a psychological, physiological and metabolic level. Nutritional problems should be carefully monitored.

Genetic testing in inherited polyposis syndromes - how and why?

There have been recent advances in genetic testing enabling accurate diagnosis of polyposis syndromes by identifying causative gene mutations, which is essential in the management of individuals with polyposis syndrome and predictive genetic testing of their extended families. There are some similarities in clinical presentation of various polyposis syndromes, which may pose a challenge to diagnosis. In this review, we discuss the clinical presentation of the main polyposis syndromes and the process of genetic testing, including the latest advancement and future of genetic testing. We aim to reiterate the importance of genetic testing in the management of polyposis syndromes, potential pitfalls associated with genetic testing and recommendations for healthcare professionals involved with the care of polyposis patients.

Familial gastric cancer: guidelines for diagnosis, treatment and periodic surveillance

Hereditary diffuse gastric cancer (HDGC) is a relatively rare disorder, with a mutated CDH1 gene as the only known cause. Carriers of a germline mutation in CDH1 have a lifetime risk of >80% of developing diffuse gastric cancer. As periodic gastric surveillance is of limited value in detecting early stages of HDGC, prophylactic gastrectomy is advised for this patient group. Little is known about other types of familial gastric cancer. The Dutch working group on hereditary gastric cancer has formulated guidelines for various aspects of medical management for families and individuals at high risk of developing gastric cancer, including criteria for referral, classification, diagnostics, and periodic gastric surveillance. These guidelines are not limited to HDGC and are therefore partially complementary to the guidelines on hereditary diffuse gastric cancer of the international gastric cancer linkage consortium (IGCLC 2010). In order to optimize the care and increase the knowledge on hereditary gastric cancer it is important to centralize medical care for these patients. National and international collaboration is warranted to improve the quality of research by increasing the size of study cohorts.

Genetic testing by cancer site: stomach

Gastric cancer is a global public health concern, ranking as the fourth leading cause of cancer mortality, with a 5-year survival of only 20%. Approximately 10% of gastric cancers appear to have a familial predisposition, and about half of these can be attributed to hereditary germline mutations. We review the genetic syndromes and current standards for genetic counseling, testing, and medical management for screening and treatment of gastric cancer. Recently, germline mutations in the E-cadherin/CDH1 gene have been identified in families with an autosomal dominant inherited predisposition to gastric cancer of the diffuse type. The cumulative lifetime risk of developing gastric cancer in CDH1 mutation carriers is up to 80%, and women from these families also have an increased risk for developing lobular breast cancer. Prophylactic gastrectomies are recommended in unaffected CDH1 mutation carriers, because screening endoscopic examinations and blind biopsies have proven inadequate for surveillance. In addition to this syndrome, gastric cancer risk is elevated in Lynch syndrome associated with germline mutations in DNA mismatch repair genes and microsatellite instability, in hereditary breast and ovarian cancer syndrome due to germline BRCA1 and BRCA2 mutations, in familial adenomatous polyposis caused by germline APC mutations, in Li-Fraumeni syndrome due to germline p53 mutations, in Peutz-Jeghers syndrome associated with germline STK11 mutations, and in juvenile polyposis syndrome associated with germline mutations in the SMAD4 and BMPR1A genes. Guidelines for genetic testing, counseling, and management of individuals with hereditary diffuse gastric cancer are suggested. A raised awareness among the physician and genetic counseling communities regarding these syndromes may allow for increased detection and prevention of gastric cancers in these high-risk individuals.

Familial gastric cancer: detection of a hereditary cause helps to understand its etiology

Worldwide, gastric cancer is one of the most common forms of cancer, with a high morbidity and mortality. Several environmental factors predispose to the development of gastric cancer, such as Helicobacter pylori infection, diet and smoking. Familial clustering of gastric cancer is seen in 10% of cases, and approximately 3% of gastric cancer cases arise in the setting of hereditary diffuse gastric cancer (HDGC). In families with HDGC, gastric cancer presents at relatively young age. Germline mutations in the CDH1 gene are the major cause of HDGC and are identified in approximately 25-50% of families which fulfill strict criteria. Prophylactic gastrectomy is the only option to prevent gastric cancer in individuals with a CDH1 mutation. However, in the majority of families with multiple cases of gastric cancer no germline genetic abnormality can be identified and therefore preventive measures are not available, except for general lifestyle advice. Future research should focus on identifying new genetic predisposing factors for all types of familial gastric cancer.