An investigation of the factors effecting high-risk individuals' decision-making about prophylactic total gastrectomy and surveillance for hereditary diffuse gastric cancer (HDGC)

Confocal endomicroscopy diagnostic criteria for early signet-ring cell carcinoma in hereditary diffuse gastric cancer

BACKGROUND

Recognition of early signet-ring cell carcinoma (SRCC) in patients with hereditary diffuse gastric cancer (HDGC) undergoing endoscopic surveillance is challenging. We hypothesized that probe-based confocal laser endomicroscopy (pCLE) might help diagnose early cancerous lesions in the context of HDGC. The aim of this study was to identify pCLE diagnostic criteria for early SRCC.

METHODS

Patients with HDGC syndrome were prospectively recruited and pCLE assessment was performed on areas suspicious for early SRCC and control regions during an endoscopic surveillance procedure. Targeted biopsies were taken for gold standard histologic assessment. In Phase I two investigators assessed video sequences off-line to identify pCLE features related to SRCC. In Phase II pCLE diagnostic criteria were evaluated in an independent video set by the investigators blinded to the histologic diagnosis. Sensitivity, specificity, accuracy, and interobserver agreement were calculated.

RESULTS

Forty-two video sequences from 16 HDGC patients were included in Phase I. Four pCLE patterns associated to SRCC histologic features were identified: (A) glands with attenuated margins, (B) glands with spiculated or irregular shape, (C) heterogenous granular stroma with sparse glands, (D) enlarged vessels with tortuous shape. In Phase II, 38 video sequences from 15 patients were assessed. Criteria A and B and C had the highest diagnostic accuracy, with a κ for interobserver agreement ranging from 0.153 to 0.565. A panel comprising these 3 criteria with a cut-off of at least one positive criterion had a sensitivity of 80.9% (95%CI:58.1-94.5%) and a specificity of 70.6% (95%CI:44.0-89.7%) for a diagnosis of SRCC.

CONCLUSIONS

We have generated and validated off-line pCLE criteria for early SRCC. Future real-time validation of these criteria is required.

Decision-making and regret in patients with germline CDH1 variants undergoing prophylactic total gastrectomy

INTRODUCTION

Prophylactic total gastrectomy (PTG) can eliminate gastric cancer risk and is recommended in carriers of a germline CDH1 pathogenic variant. PTG has established risks and potential life-long morbidity. Decision-making regarding PTG is complex and not well-understood.

METHODS

Individuals with germline CDH1 pathogenic or likely pathogenic variants who underwent surveillance endoscopy and recommended for PTG were evaluated. Factors associated with decision to pursue PTG (PTG^pos) or not (PTG^neg) were queried. A decision-regret survey was administered to patients who elected PTG.

RESULTS

Decision-making was assessed in 120 patients. PTG^pos patients (63%, 76/120) were younger than PTG^neg (median 45 vs 58 years) and more often had a strong family history of gastric cancer (80.3% vs 34.1%). PTG^pos patients reported decision-making based on family history more often and decided soon after diagnosis (8 vs 27 months) compared with PTG^neg. Negative endoscopic surveillance results were more common among PTG^neg patients. Age >60 years, male sex and longer time to decision were associated with deferring PTG. Strong family history, a family member who died of gastric cancer and carcinoma on endoscopic biopsies were associated with decision to pursue PTG. In the PTG^pos group, 30 patients (43%) reported regret which was associated with occurrence of a postoperative complication and no carcinoma detected on final pathology.

CONCLUSION

The decision to undergo PTG is influenced by family cancer history and surveillance endoscopy results. Regret is associated with surgical complications and pathological absence of cancer. Individual cancer-risk assessment is necessary to improve pre-operative counselling and inform the decision-making process.

TRIAL REGISTRATION NUMBER

NCT03030404.

Hereditary Diffuse Gastric Cancer

Hereditary diffuse gastric cancer (HDGC) is a dominantly inherited cancer syndrome characterized by a high incidence of diffuse gastric cancer (DGC) and lobular breast cancer (LBC). HDGC is caused by germline mutations in 2 genes involved in the epithelial adherens junction complex, CDH1 and CTNNA1. We discuss the genetics of HDGC and the variability of its clinical phenotype, in particular the variable penetrance of advanced DGC and LBC, both within and between families. We review the pathology of the disease, the mechanism of tumor initiation, and its natural history. Finally, we describe current best practice for the clinical management of HDGC, including emerging genetic testing criteria for the identification of new families, methods for endoscopic surveillance, the complications associated with prophylactic surgery, postoperative quality of life, and the emerging field of HDGC chemoprevention.

Endoscopic surveillance with systematic random biopsy for the early diagnosis of hereditary diffuse gastric cancer: a prospective 16-year longitudinal cohort study

BACKGROUND

Hereditary diffuse gastric cancer, generally caused by germline pathogenic variants in CDH1, presents with early-onset signet ring cell carcinoma. Prophylactic total gastrectomy is the definitive treatment. Endoscopic surveillance can inform the timing of prophylactic total gastrectomy through detection of microscopic signet ring cell carcinoma foci. However, evidence is scarce about the optimal endoscopic sampling technique and characterisation of signet ring cell carcinoma foci in hereditary diffuse gastric cancer. We aimed to formally assess the diagnostic yield of different sampling strategies and to identify criteria for the characterisation of endoscopic lesions.

METHODS

For this prospective longitudinal cohort study, we included individuals aged 18 years or older at the Cambridge University Hospitals National Health Service (NHS) Foundation Trust who fulfilled testing criteria for hereditary diffuse gastric cancer between June 1, 2005, and July 31, 2021. The primary outcome was detection of intramucosal signet ring cell carcinoma foci. We assessed the detection rate and anatomical location of signet ring cell carcinoma in random biopsy samples taken according to a systematic protocol compared with biopsies targeted to endoscopic findings. Endoscopic lesions were examined with white-light and narrow band imaging with magnification to assess the likelihood of cancerous foci.

FINDINGS

145 individuals were included, of whom 68 (47%) were male and 92 (63%) carried the CDH1 pathogenic variant. 58 (40%) patients were diagnosed with invasive signet ring cell carcinoma over a median follow-up time of 51 months (IQR 18-80). The first diagnosis of signet ring cell carcinoma was most commonly made from random biopsies (29 [50%] of 58 patients), rather than targeted biopsies (15 [26%] patients). The anatomical distribution of signet ring cell carcinoma foci detected by random biopsies more accurately reflected those identified in prophylactic total gastrectomy specimens than did targeted biopsies. Omitting random biopsies in our cohort would have led to an under-diagnosis rate of 42%. Using a novel panel of endoscopic criteria, gastric lesions containing signet ring cell carcinoma were predicted with a sensitivity of 67·3% and a specificity of 90·2%.

INTERPRETATION

Random biopsies enhance the early detection of signet ring cell carcinoma and are complementary to targeted biopsies in surveillance of hereditary diffuse gastric cancer. This sampling method should be the standard of care when performing all surveillance endoscopies for individuals with hereditary diffuse gastric cancer.

FUNDING

UK Medical Research Council.

Attitudes toward preimplantation genetic testing and quality of life among individuals with hereditary diffuse gastric cancer syndrome

BACKGROUND

Hereditary Diffuse Gastric Cancer (HDGC) syndrome is an autosomal dominant hereditary cancer predisposition associated with germline pathogenic/likely pathogenic variants in the CDH1 gene. Identifying early stage HDGC is difficult, and prophylactic measures can be effective in preventing incidence. Preimplantation Genetic Testing (PGT) can provide information about CDH1 variant status, HDGC risk, and limit familial transmission of CDH1 variants. To date, however, little is known about the attitudes of individuals with CDH1 variants towards PGT.

METHODS

Given that little is known about the reproductive attitudes of individuals with HDGC, we recruited participants with CDH1 variants from a familial gastric cancer registry and administered a cross-sectional survey with open- and closed-ended response items. We assessed attitudes regarding PGT and the effect of HDGC on quality of life.

RESULTS

Participants (n = 21) were predominantly partnered (61.9%), had a personal cancer history (71.4%), and had biological children (71.4%). Interest in learning about PGT was high; 66.7% of participants were interested in PGT and 90.5% approved of healthcare providers discussing PGT with individuals with CDH1 variants. Attitudes regarding personal use were varied. Among all participants, 35% would not, 25% were uncertain, and 40% would use PGT. Personal philosophy and preferences for family and reproduction were key factors related to PGT attitudes. HDGC had moderate effects on participants' quality of life, including social relationships, health behaviors, and emotional experiences including worry about cancer risk and guilt regarding familial implications.

CONCLUSION

PGT was identified by participants as acceptable for use in a variety of contexts and benefits of reproductive counseling involving PGT may extend beyond CDH1 carriers to family members' reproductive behaviors. Dispositions towards PGT are governed by personal philosophy or belief systems. These findings can help guide providers counseling individuals with CDH1 variants.

Becoming and being a parent with an inherited predisposition to diffuse gastric cancer: A qualitative study of young adults with a CDH1 pathogenic variant

PURPOSE

This study explored the experiences of young people with hereditary diffuse gastric cancer (HDGC), an inherited cancer predisposition syndrome, as they navigate becoming and being a parent.

DESIGN

We used interpretive description and conducted semi-structured interviews with 13 young Australians (18-39 years) with a CDH1 pathogenic variant (PV). Data were analyzed using team-based, reflexive thematic analysis.

FINDINGS

Participants' reproductive decisions centered on the perceived manageability of HDGC, namely via gastrectomy, and timing of their genetic testing. Participants yet to have children and those with challenging gastrectomy experiences favored using reproductive technologies to prevent passing on their PV. Parents who had children before genetic testing described complicated decisions about having more children. Gastrectomy was considered a parental responsibility but recovery diminished parenting abilities.

CONCLUSION

Young people with HDGC face unique challenges navigating reproductive decision-making and parenting with gastrectomy. Findings lend credence to calls for longitudinal, developmentally sensitive genetic counseling services.

Hereditary Diffuse Gastric Cancer: Molecular Genetics, Biological Mechanisms and Current Therapeutic Approaches

Hereditary diffuse gastric cancer is an autosomal dominant syndrome characterized by a high prevalence of diffuse gastric cancer and lobular breast cancer. It is caused by inactivating mutations in the tumor suppressor gene CDH1. Genetic testing technologies have become more efficient over the years, also enabling the discovery of other susceptibility genes for gastric cancer, such as CTNNA1 among the most important genes. The diagnosis of pathogenic variant carriers with an increased risk of developing gastric cancer is a selection process involving a multidisciplinary team. To achieve optimal long-term results, it requires shared decision-making in risk management. In this review, we present a synopsis of the molecular changes and current therapeutic approaches in HDGC based on the current literature.

CDH1 variants leading to gastric cancer risk management decision-making experiences in emerging adults: 'I am not ready yet'

Pathogenic/likely pathogenic variants (PLPV) in CDH1 are associated with a significantly increased lifetime risk for diffuse gastric cancer, with an average age of onset of 47 years. CDH1 PLPV carriers are recommended to have prophylactic total gastrectomy (PTG) or routine endoscopy surveillance. Emerging adults (EAs) may have unique circumstances that affect their medical management decision-making about PTG versus endoscopy. The study aim was to use qualitative interpretative phenomenological analysis method to understand the lived experience and medical management decision-making process for EAs carrying a CDH1 PLPV. Eligible participants were unaffected CDH1 PLPV carriers, ages 18 to 29, who had not undergone PTG and had discussed CDH1 medical management with a health provider. Semi-structured telephone interviews were transcribed verbatim and analyzed for major themes. Results show EAs wanted to avoid developing diffuse gastric cancer, but most do not feel they are ready for PTG. They had worries about PTG related to their identity exploration, financial stability, and careers. Most did not want to pass the PLPV to their children; however, the cost of preimplantation genetic testing with in vitro fertilization was a concern. Family medical history and self-understanding of endoscopy and PTG highly influenced medical management decision-making. Understanding of diffuse gastric cancer detection rate using endoscopy was inconsistent among participants. Body image was not a concern for most, but they worry about dietary restrictions after PTG. Lastly, connection to peers having the same experience was important. These findings increase our understanding of the medical management decision-making challenges for EA CDH1 carriers. EAs may take an extended time to decide what option is right for them. Thus, genetic counseling for CDH1 PLPV EA carriers requires long-term support and education.

Young people's experiences of a CDH1 pathogenic variant: Decision-making about gastric cancer risk management

The most effective option for gastric cancer risk management in individuals with a CDH1 germline pathogenic or likely pathogenic variant (PV) in Australia is prophylactic total gastrectomy (PTG). There is, however, increasing confidence in endoscopic surveillance as a risk management strategy thus affording individuals with a CDH1 PV with challenging decisions regarding their gastric cancer risk management. For young people, this decision-making comes at a complex development stage of emerging and young adulthood. This study aims to explore the factors that influence young people's decision-making about their gastric cancer risk management due to a CDH1 PV. Potential participants were identified and approached through the Parkville Familial Cancer Centre in Melbourne, Australia. Thematic analysis was used to interpret and analyze the data. Qualitative interviews were conducted with 13 people with a CDH1 PV aged 18 to 39 years, inclusive. The interviews found that participants' familial and shared experiences of cancer and risk management, perceived tolerance of uncertainty, and desire for control over their cancer risk were fundamental in their decision-making about their gastric cancer risk management. The participants' young adult life stage was also deemed particularly important in decisions about the timing of PTG. The findings of this study are vital to inform decisional counseling discussions with this unique population.

CDH1 Gene Mutation Hereditary Diffuse Gastric Cancer Outcomes: Analysis of a Large Cohort, Systematic Review of Endoscopic Surveillance, and Secondary Cancer Risk Postulation

Simple Summary

Some patients carry a mutated copy of the CDH1 gene that can lead to a very rare form of hereditary gastric cancer called signet-ring cell adenocarcinoma (SRCC). SRCCs rarely form visible tumors prior to spreading. Hence, patients are recommended to have prophylactic gastrectomies at a young age. Many patients wish to avoid surgery and thus have regular checks with upper endoscopy with biopsies to rule out cancer. Further, these patients may also be at risk of other cancers beyond the already known breast cancer risks, but this is not known. In this study, we show that despite systematic biopsy protocols, many early cancers might be missed on endoscopy. Therefore, patients should not rely on endoscopy to delay surgery. These patients may also be at increased risk of colorectal SRCC, which has very poor survival outcomes. To confirm this, we need a central database that captures outcomes for this patient population.

Abstract

Hereditary diffuse gastric cancer (HDGC) is a rare signet-ring cell adenocarcinoma (SRCC) linked to CDH1 (E-cadherin) inactivating germline mutations, and increasingly other gene mutations. Female CDH1 mutation carriers have additional risk of lobular breast cancer. Risk management includes prophylactic total gastrectomy (PTG). The utility of endoscopic surveillance is unclear, as early disease lacks macroscopic lesions. The current systematic biopsy protocols have unknown efficacy, and other secondary cancer risks are postulated. We conducted a retrospective study of consecutive asymptomatic HDGC patients undergoing PTG, detailing endoscopic, pathologic, and outcome results. A systematic review compared endoscopic biopsy foci detection via random sampling versus Cambridge Protocol against PTG findings. A population-level secondary-cancer-risk postulation among sporadic gastric SRCC patients was completed using the Surveillance, Epidemiology, and End Results database. Of 97 patients, 67 underwent PTG, with 25% having foci detection on random endoscopic biopsy despite 75% having foci on final pathology. There was no improvement in the endoscopic detection rate by Cambridge Protocol. The postulated hazard ratio among sporadic gastric SRCC patients for a secondary colorectal SRCC was three-fold higher, relative to conventional adenocarcinoma patients. Overall, HDGC patients should not rely on endoscopic surveillance to delay PTG, and may have secondary SRCC risks. A definitive determination of actual risk requires collaborative patient outcome data banking.

Single-bite versus double-bite technique for mapping biopsies during endoscopic surveillance for hereditary diffuse gastric cancer: a single-center, randomized trial

BACKGROUND : Endoscopic surveillance is recommended in patients with hereditary diffuse gastric cancer (HDGC) who refuse or want to delay surgery. Because early signet-ring cell carcinoma (SRCC) can be inconspicuous, the current surveillance endoscopy protocol entails 30 random biopsies, which are time-consuming. This study aimed to compare single-bite and double-bite techniques in HDGC surveillance. METHODS : Between October 2017 and December 2018, consecutive patients referred for HDGC surveillance were prospectively randomized to the single- or double-bite arm. The primary outcome was the diagnostic yield for SRCC foci. Secondary outcomes were: procedural time for random biopsies; comfort score; biopsy size; and quality of specimens, the latter assessed by the presence of muscularis mucosa, crush artifact, and proportion usable for diagnostic assessment. RESULTS : 25 patients were randomized to the single-bite arm and 23 to the double-bite arm. SRCC foci were detected in three and four patients in the single- and double-bite arms, respectively (P = 0.70). The procedural time for the double-bite arm (12 minutes, interquartile range [IQR] 4) was significantly shorter than for the single-bite arm (15 minute, IQR 6; P = 0.01), but comfort scores were similar. The size of the biopsies in the double-bite arm was significantly smaller than in single-bite arm (2.5 mm vs. 3.0 mm; P < 0.001) but this did not affect the presence of muscularis mucosa (P = 0.73), artifact level (P = 0.11), and diagnostic utility (P = 0.051). CONCLUSION : For patients undergoing HDGC surveillance, the double-bite technique is significantly faster than the single-bite technique. The diagnostic yield for SRCC and the biopsy quality were similar across both groups.

Barriers and facilitators to CDH1 carriers contemplating or undergoing prophylactic total gastrectomy

Hereditary diffuse gastric cancer (HDGC) is an inherited cancer syndrome associated with high lifetime risk of diffuse-type gastric cancer. Current guidelines recommend individuals with HDGC undergo prophylactic total gastrectomy (PTG) to eliminate this risk. However, PTG is associated with significant lifestyle changes, post-surgical recovery, and symptom burden. This study examined factors related to decision-making about PTG in three groups of individuals who: (1) underwent PTG immediately after receiving genetic testing results; (2) delayed PTG by ≥ 1 year or; (3) declined PTG. Participants were recruited from a familial gastric cancer registry at a tertiary care hospital. Patients with CDH1 pathogenic or likely pathogenic variants who contemplated and/or underwent PTG were eligible. 24 individuals contemplated PTG: 9 had immediate surgery (within a year), 8 delayed surgery, and 7 declined surgery. Data on PTG barriers and facilitators were obtained on all participants using quantitative surveys (n = 7), qualitative interviews (n = 8) or both methods (n = 9). PTG barriers included age, positive beliefs about screening, close relatives with negative PTG experiences, fertility-related concerns, and life stress. Facilitators included social support, trust in healthcare providers, understanding risk, negative beliefs about screening, family-related factors, positive or abnormal screening results, and positive attitude toward PTG. This study highlights factors related to the PTG decision-making process among individuals with HDGC from three distinct groups. Future research should explore educational interventions aimed at addressing surgery-related concerns and the limitations of screening, and might also consider incorporating close relatives as informational supports.

Paving the Way: A Grounded Theory of Discovery and Decision Making for Individuals With the CDH1 Marker

PURPOSE

To understand the process of discovery and decision making for adults with the CDH1 marker for hereditary diffuse gastric cancer and inherited breast cancer.

PARTICIPANTS & SETTING

Purposeful sampling included 20 participants.

METHODOLOGIC APPROACH

Grounded theory with constant comparison was used.

FINDINGS

The decision-making process of Paving the Way addresses the challenges for individuals diagnosed with the CDH1 marker. The theory explains the process of learning the risk, discerning testing, choosing iterative individual interventions, and adjusting postoperatively while normalizing to live longer.

IMPLICATIONS FOR NURSING

The process explains and describes the nine factors for decision making and predicts the timing for nursing interventions for genetic testing and pre- and postoperative assessment and planning.

CDH1-related blepharocheilodontic syndrome is associated with diffuse gastric cancer risk

We report the first case of diffuse gastric cancer in an individual with familial blepharocheilodontic syndrome (BCD) due to a germline CDH1 likely pathogenic variant. To date, other BCD affected relatives are nonpenetrant for diffuse gastric cancer posing challenges to counseling regarding gastric and breast cancer surveillance, and preventative total gastrectomy.

Optimal Timing of Total Gastrectomy to Prevent Diffuse Gastric Cancer in Individuals With Pathogenic Variants in CDH1

BACKGROUND & AIMS

Carriers of pathogenic variants in CDH1 have a high risk of hereditary diffuse gastric cancer (HDGC). Guidelines recommend prophylactic total gastrectomy (PTG) at age 20-30 years, although there is controversy over the optimal age. We developed a simulation model to analyze the effects of PTG at different ages on quality-adjusted life-years (QALYs), cancer mortality, and life expectancy.

METHODS

We used a Markov model of HDGC progression associated with pathogenic variants in CDH1 to simulate outcomes of hypothetical cohorts with different ages at time of PTG (ages 20-79 years). Model inputs including health state transition probabilities, mortality and complication rates, quality of life utility values, and endoscopic surveillance sensitivity were derived from publications. The primary outcome, used to determine the optimal strategy, was age at which PTG yielded the highest QALYs. Secondary outcomes were cancer mortality and unadjusted life-years.

RESULTS

Our model found that for men, the optimal age for PTG is 39 years, resulting in 32.01 incremental QALYs, 58.81 life-years (biologic age, 72.81 years), and lifetime cancer mortality of 8.5%. Incorporating endoscopic surveillance prior to PTG decreased cancer mortality to 6.7%, but had lower QALYs (31.59). PTG at age 30 reduced cancer mortality to 3.2%, with 31.45 incremental QALYs. For women, the optimal age for PTG was calculated to be 30 years, with 33.09 incremental QALYs, 66.17 life-years (biologic age, 80.17 years), and lifetime cancer mortality of 1.6%. Addition of endoscopic surveillance did not decrease the risk of HDGC mortality in women.

CONCLUSIONS

Using a Markov model of HDGC progression associated with pathogenic variants in CDH1 to simulate outcomes, we found the optimal ages for PTG to be 39 years for men and 30 years for women, when QALYs are the primary endpoint. These ages for PTG are older than those of current recommendations.

[What attitude to women at high risk of breast cancer?]

In France, breast cancer is the most common cancer among women and the leading cause of cancer deaths. Identifying women with a "high" or "very high" breast cancer risk, according the terminology of the Haute Autorité de Santé 2014 guidelines, is essential to offer them special cares in term of screening and prevention. Women genetically predisposed have a very high risk of breast cancer. During the oncogenetic specialist consultation, familial and personal history of cancer is taken into account to evaluate the risk of hereditary Breast/Ovarian syndrome and thus the need of a genetic screening. In 2017, a list of 13 genes involved in hereditary ovarian or breast cancer has been established in France (Genetic and Cancer Group - Unicancer). Women carrying a BRCA1, BRCA2, PALB2, TP53, CDH1, PTEN mutation have a higher risk of breast cancer and are considered as "high risk". Therefore, medical breast surveillance similar to carriers of BRCA1/BRCA2 mutation is recommended for these patients (INCa guidelines 2017). However a mutation in one of those genes is only identified in approximatively 10 % of the screened families. The oncogenetic specialist's assessment distinguishes families in which women remain at a "high" risk of breast cancer (HAS 2014 for screening) from those where women have a "very high" risk (INCa guidelines 2017 for screening and prevention).

Early-onset gastric cancer is a distinct disease with worrisome trends and oncogenic features

BACKGROUND

Overall the incidence of gastric cancer is declining in the United States; however, the incidence of early-onset gastric cancer is increasing. We sought to elucidate clinical and genomic characteristics and risk factors for early-onset gastric cancer compared with late-onset gastric cancer.

METHODS

We utilized the Surveillance, Epidemiology, and End Results database (1973-2015), the Behavioral Risk Factor Surveillance Survey, and The Cancer Genome Atlas to characterize early-onset gastric cancer.

RESULTS

The incidence of early-onset gastric cancer increased during the study period and now comprises >30% of all gastric cancer in the United States. Early-onset gastric cancer was associated with higher grade (55.2 vs 46.9%), signet-ring cells (19.0 vs 10.4%), diffuse histology (25.7 vs 15.0%), and metastatic disease (49.5 vs 40.9%, all P < .01) compared with late-onset gastric cancer. Early-onset gastric cancer was more likely to be Epstein-Barr virus (7.7 vs 5.1%) or genomically stable (22.5 vs 8.1%) subtype, whereas late-onset gastric cancer was more likely to be microsatellite instability subtype (18.6 vs 5.6%; all P < .01). Risk factors for gastric cancer were less correlated with early-onset gastric cancer compared with late-onset gastric cancer.

CONCLUSION

The incidence of early-onset gastric cancer has been steadily increasing in the United States, comprising >30% of new gastric cancer cases today. Early-onset gastric cancer is genetically and clinically distinct from traditional gastric cancer. Additional investigations are warranted to better understand this alarming phenomenon.

The role of endoscopy in the management of hereditary diffuse gastric cancer syndrome

Hereditary diffuse gastric cancer (HDGC) syndrome is an inherited cancer risk syndrome associated with pathogenic germline CDH1 variants. Given the high risk for developing diffuse gastric cancer, CDH1 carriers are recommended to undergo prophylactic total gastrectomy for cancer risk reduction. Current guidelines recommend upper endoscopy in CDH1 carriers prior to surgery and then annually for individuals deferring prophylactic total gastrectomy. Management of individuals from HDGC families without CDH1 pathogenic variants remains less clear, and management of families with CDH1 pathogenic variants in the absence of a family history of gastric cancer is particularly problematic at present. Despite adherence to surveillance protocols, endoscopic detection of cancer foci in HDGC is suboptimal and imperfect for facilitating decision-making. Alternative endoscopic modalities, such as chromoendoscopy, endoscopic ultrasound, and other non-white light methods have been utilized, but are of limited utility to further improve cancer detection and risk stratification in HDGC. Herein, we review what is known and what remains unclear about endoscopic surveillance for HDGC, among individuals with and without germline CDH1 pathogenic variants. Ultimately, the use of endoscopy in the management of HDGC remains a challenging arena, but one in which further research to improve surveillance is crucial.

Patients' Medical and Psychosocial Experiences After Detection of a CDH1 Variant With Multigene Panel Testing

PURPOSE

Germline CDH1 pathogenic variants (PV) are associated with hereditary diffuse gastric cancer and lobular breast cancer. Although prevalence of CDH1 PV is low in the general population, detection of these variants is increasing with the growing use of multigene panel testing. Little is known about the experiences of individuals tested for CDH1 variants in the multigene panel testing era.

METHODS

Participants recruited from the Prospective Registry of Multiplex Testing completed a cross-sectional self-report survey regarding CDH1 genetic testing experiences, medical management, and psychosocial adaptation.

RESULTS

Discordance existed in interpretations of CDH1 results; 13.3% of cases had disagreements in variant classifications among commercial laboratories, and 21.4% had disagreements between participant self-report and ClinVar classification. Survey data were available from 57 individuals reporting either PV (n = 16) or variants of uncertain significance (VUS; n = 41). Those with PV were more likely than those with VUS to report receiving a recommendation for prophylactic gastrectomy, although only 40.0% of those with PV received this recommendation. Participants with VUS were less satisfied with their health care providers' knowledge and reported less CDH1 knowledge, distress, and worry about discrimination. Participants with PV perceived greater breast cancer risks, but similar gastric cancer risks, as those with VUS.

CONCLUSION

Few individuals with CDH1 PV report receiving recommendations for prophylactic gastrectomy, and no differences in perceived gastric cancer risk were observed based on participants' CDH1 results, suggesting serious unmet informational needs.

Hereditary diffuse gastric cancer: how to look for and how to manage it

With a current molecular revolution, hereditary gastric cancer represents a small group of patients that require a special multidisciplinary treatment. Surgeons being a member of the multidisciplinary teams are an important part of the diagnosis, treatment and follow-up of these patients. The prophylactic nature of the gastrectomy with all different problems associated with this procedure need to be widely discussed with patients. We present a review of how to look for and how to manage a hereditary diffuse-type gastric cancer.

Identity, community and care in online accounts of hereditary colorectal cancer syndrome

Sociological literature has explored how shifts in the point at which individuals may be designated as diseased impact upon experiences of ill health. Research has shown that experiences of being genetically "at risk" are shaped by and shape familial relations, coping strategies, and new forms of biosociality. Less is known about how living with genetic risk is negotiated in the everyday and over time, and the wider forms of identity, communities and care this involves. This article explores these arrangements drawing on online bloggers' accounts of Familial Adenomatous Polyposis (FAP). We show how accounts of genetic risk co-exist with more palpable experiences of FAP in everyday life, notably the consequences of prophylactic surgeries. We consider how the act of blogging represents but also constitutes everyday experiences of hereditary cancer syndrome as simultaneously ordinary and exceptional, and reflect on the implications of our analysis for understanding experiences of genetic cancer risk.

Comparative study of endoscopic surveillance in hereditary diffuse gastric cancer according to CDH1 mutation status

BACKGROUND AND AIMS

Hereditary diffuse gastric cancer (HDGC) accounts for 1% of gastric cancer cases. For patients with a germline CDH1 mutation, risk-reducing gastrectomy is recommended. However, for those delaying surgery or for families with no causative mutation identified, regular endoscopy is advised. This study aimed to determine the yield of signet ring cell carcinoma (SRCC) foci in individuals with a CDH1 pathogenic variant compared with those without and how this varies with successive endoscopies.

METHODS

Patients fulfilling HDGC criteria were recruited to a prospective longitudinal cohort study. Endoscopy was performed according to a strict protocol with visual inspection followed by focal lesion and random biopsy sampling to detect foci of SRCC. Survival analysis determined progression to finding of SRCC according to CDH1 mutation status. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 and 36-item Short Form Health Survey questionnaires assessed quality of life before surveillance and each endoscopy.

RESULTS

Eighty-five individuals fulfilling HDGC criteria underwent 201 endoscopies; 54 (63.5%) tested positive for CDH1 mutation. SRCC yield was 61.1% in CDH1 mutation carriers compared with 9.7% in noncarriers, and mutation-positive patients had a 10-fold risk of SRCC on endoscopy compared with those with no mutation detected (P < .0005). Yield of SRCC decreased substantially with subsequent endoscopies. Surveillance was associated with improved psychological health.

CONCLUSIONS

SRCC foci are prevalent in CDH1 mutation carriers and can be detected at endoscopy using a standardized, multiple biopsy sampling protocol. Decreasing yield over time suggests that the frequency of endoscopy might be reduced. For patients with no CDH1 pathogenic variant detected, the cost-to-benefit ratio needs to be assessed in view of the low yield.

Germline mutations in hereditary diffuse gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide. Among which, about 1%-3% of gastric cancer patients were characterized by inherited gastric cancer predisposition syndromes, knowing as hereditary diffuse gastric cancer (HDGC). Studies reported that CDH1 germline mutations are the main cause of HDGC. With the help of rapid development of genetic testing technologies and data analysis tools, more and more researchers focus on seeking candidate susceptibility genes for hereditary cancer syndromes. In addition, National Comprehensive Cancer Network (NCCN) guidelines recommend that the patients of HDGC carrying CDH1 mutations should undergo prophylactic gastrectomy or routine endoscopic surveillances. Therefore, genetic counseling plays a key role in helping individuals with pathogenic mutations make appropriate risk management plans. Moreover, experienced and professional genetic counselors as well as a systematic multidisciplinary team (MDT) are also required to facilitate the development of genetic counseling and benefit pathogenic mutation carriers who are in need of regular and standardized risk management solutions. In this review, we provided an overview about the germline mutations of several genes identified in HDGC, suggesting that these genes may potentially act as susceptibility genes for this malignant cancer syndrome. Furthermore, we introduced information for prevention, diagnosis and risk management of HDGC. Investigations on key factors that may have effect on risk management decision-making and genetic data collection of more cancer syndrome family pedigrees are required for the development of HDGC therapeutic strategies.

High-risk individuals' perceptions of reproductive genetic testing for CDH1 mutations

Reproductive genetic testing- PreNatal Diagnosis (PND) and Preimplantation Genetic Diagnosis (PGD)-for CDH1 mutations associated with Hereditary Diffuse Gastric Cancer (HDGC)is available in the UK. This qualitative interview study examined high-risk individuals' (n = 35) views of CDH1 reproductive genetic testing. Interviewees generally regarded reproductive genetic testing as an acceptable form of HDGC risk management. However, some were concerned that their genetic risks required them to plan reproduction and anticipated difficulties communicating this to reproductive partners. Individuals had a preference for PGD over PND because it avoided the need for a termination of pregnancy. However, those who had not yet had children expressed concerns about having to undergo IVF procedures and worries about their effectiveness and the need for embryo selection in PGD. It is suggested that high-risk individuals are provided with access to reproductive genetic counselling.

A novel mutation in the CDH1 gene in a Spanish family with hereditary diffuse gastric cancer

Hereditary diffuse gastric cancer (HDGC) is an inherited form of diffuse type gastric cancer. Germline CDH1 mutations have been identified in approximately 15-50 % of affected kindred that meet the clinical criteria for HDGC. If any of the criteria is met the individual is referred to genetic counseling and CDH1 testing is offered. In this report we present the case of a Spanish family with HDGC harboring a novel CDH1 mutation. A 47 year-old female with a diagnostic of gastric adenocarcinoma and some of her relatives were tested. Study of the entire CDH1 gene, including intron-exon boundaries, by PCR and sequencing and immunohistochemical determination of the expression of E-cadherin were performed. A novel heterozygous deletion in exon 9 of CDH1 gene (c.1220_1220delC, p.P407Qfs10), was found in the proband, one sister and a nephew. It generates a premature stop codon giving rise to a truncated protein that leads to a pathogenic variant. Expression of E-cadherin was absent or frankly reduced in the proband's tumor but normal in tumor cells of great-uncle. After these results, the sister underwent prophylactic total gastrectomy, and the nephew is under annual endoscopic surveillance. Personal or familial history of diffuse gastric cancer, above all at young age, should encourage CDH1 genetic testing. In this sense, the review of the criteria and the addition in the last guideline of the recommendation: "other families in which genetic testing may also be considered" broadens the number of individuals at risk detected. Since there are not reliable methods for early detection, DGC is usually diagnosed at an advanced stage and consequently associated with a poorer outcome. Thus, CDH1 mutations detection contributes to an improvement in diagnosis and therapeutic intervention.