Associations between pathological features and risk of metachronous colorectal cancer.

Survivors of colorectal cancer (CRC) are at risk of developing another primary colorectal cancer - metachronous CRC. Understanding which pathological features of the first tumour are associated with risk of metachronous CRC might help tailor existing surveillance guidelines. Population-based CRC cases were recruited from the United States, Canada and Australia between 1997 and 2012 and followed prospectively until 2022 by the Colon Cancer Family Registry. Metachronous CRC was defined as a new primary CRC diagnosed at least 1 year after the initial CRC. Those with the genetic cancer predisposition Lynch syndrome or MUTYH mutation carriers were excluded. Cox regression models were fitted to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for the associations. Of 6085 CRC cases, 138 (2.3%) were diagnosed with a metachronous CRC over a median follow-up time of 12 years (incidence: 2.0 per 1000 person-years). CRC cases with a synchronous CRC were 3.4-fold more likely to develop a metachronous CRC (adjusted HR: 3.36, 95% CI: 1.89-5.98) than those without a synchronous tumour. CRC cases with MMR-deficient tumours had a 72% increased risk of metachronous CRC (adjusted HR: 1.72, 95% CI: 1.11-2.64) compared to those with MMR-proficient tumours. Compared to cases who had an adenocarcinoma histologic type, those with an undifferentiated histologic type were 77% less likely to develop a metachronous CRC (adjusted HR: 0.23, 95% CI: 0.06-0.94). Existing surveillance guidelines for CRC survivors could be updated to include increased surveillance for those whose first CRC was diagnosed with a synchronous CRC or was MMR-deficient.

A comparison of DNA sequencing and gene expression profiling to assist tissue of origin diagnosis in cancer of unknown primary.

Cancer of unknown primary (CUP) is a syndrome defined by clinical absence of a primary cancer after standardised investigations. Gene expression profiling (GEP) and DNA sequencing have been used to predict primary tissue of origin (TOO) in CUP and find molecularly guided treatments; however, a detailed comparison of the diagnostic yield from these two tests has not been described. Here, we compared the diagnostic utility of RNA and DNA tests in 215 CUP patients (82% received both tests) in a prospective Australian study. Based on retrospective assessment of clinicopathological data, 77% (166/215) of CUPs had insufficient evidence to support TOO diagnosis (clinicopathology unresolved). The remainder had either a latent primary diagnosis (10%) or clinicopathological evidence to support a likely TOO diagnosis (13%) (clinicopathology resolved). We applied a microarray (CUPGuide) or custom NanoString 18-class GEP test to 191 CUPs with an accuracy of 91.5% in known metastatic cancers for high-medium confidence predictions. Classification performance was similar in clinicopathology-resolved CUPs - 80% had high-medium predictions and 94% were concordant with pathology. Notably, only 56% of the clinicopathology-unresolved CUPs had high-medium confidence GEP predictions. Diagnostic DNA features were interrogated in 201 CUP tumours guided by the cancer type specificity of mutations observed across 22 cancer types from the AACR Project GENIE database (77,058 tumours) as well as mutational signatures (e.g. smoking). Among the clinicopathology-unresolved CUPs, mutations and mutational signatures provided additional diagnostic evidence in 31% of cases. GEP classification was useful in only 13% of cases and oncoviral detection in 4%. Among CUPs where genomics informed TOO, lung and biliary cancers were the most frequently identified types, while kidney tumours were another identifiable subset. In conclusion, DNA and RNA profiling supported an unconfirmed TOO diagnosis in one-third of CUPs otherwise unresolved by clinicopathology assessment alone. DNA mutation profiling was the more diagnostically informative assay. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Marginal zone lymphomas: a consensus practice statement from the Australasian Lymphoma Alliance.

Marginal zone lymphomas (MZLs) are a rare, indolent group of non-Hodgkin lymphomas with different diagnostic, genetic and clinical features and therapeutic implications. The most common is extranodal MZL of mucosa-associated lymphoid tissue, followed by splenic MZL and nodal MZL. Patients with MZL generally have good outcomes with long survival rates but frequently have a relapsing/remitting course requiring several lines of therapy. The heterogeneous presentation and relapsing course present the clinician with several diagnostic and therapeutic challenges. This position statement presents evidence-based recommendations in the setting of Australia and New Zealand.

DEMoS: a deep learning-based ensemble approach for predicting the molecular subtypes of gastric adenocarcinomas from histopathological images.

MOTIVATION: The molecular subtyping of gastric cancer (adenocarcinoma) into four main subtypes based on integrated multiomics profiles, as proposed by The Cancer Genome Atlas (TCGA) initiative, represents an effective strategy for patient stratification. However, this approach requires the use of multiple technological platforms, and is quite expensive and time-consuming to perform. A computational approach that uses histopathological image data to infer molecular subtypes could be a practical, cost- and time-efficient complementary tool for prognostic and clinical management purposes. RESULTS: Here, we propose a deep learning ensemble approach (called DEMoS) capable of predicting the four recognized molecular subtypes of gastric cancer directly from histopathological images. DEMoS achieved tile-level area under the receiver-operating characteristic curve (AUROC) values of 0.785, 0.668, 0.762 and 0.811 for the prediction of these four subtypes of gastric cancer [i.e. (i) Epstein-Barr (EBV)-infected, (ii) microsatellite instability (MSI), (iii) genomically stable (GS) and (iv) chromosomally unstable tumors (CIN)] using an independent test dataset, respectively. At the patient-level, it achieved AUROC values of 0.897, 0.764, 0.890 and 0.898, respectively. Thus, these four subtypes are well-predicted by DEMoS. Benchmarking experiments further suggest that DEMoS is able to achieve an improved classification performance for image-based subtyping and prevent model overfitting. This study highlights the feasibility of using a deep learning ensemble-based method to rapidly and reliably subtype gastric cancer (adenocarcinoma) solely using features from histopathological images. AVAILABILITY AND IMPLEMENTATION: All whole slide images used in this study was collected from the TCGA database. This study builds upon our previously published HEAL framework, with related documentation and tutorials available at http://heal.erc.monash.edu.au. The source code and related models are freely accessible at https://github.com/Docurdt/DEMoS.git. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

A tumor focused approach to resolving the etiology of DNA mismatch repair deficient tumors classified as suspected Lynch syndrome.

Routine screening of tumors for DNA mismatch repair (MMR) deficiency (dMMR) in colorectal (CRC), endometrial (EC) and sebaceous skin (SST) tumors leads to a significant proportion of unresolved cases classified as suspected Lynch syndrome (SLS). SLS cases (n = 135) were recruited from Family Cancer Clinics across Australia and New Zealand. Targeted panel sequencing was performed on tumor (n = 137; 80×CRCs, 33×ECs and 24xSSTs) and matched blood-derived DNA to assess for microsatellite instability status, tumor mutation burden, COSMIC tumor mutational signatures and to identify germline and somatic MMR gene variants. MMR immunohistochemistry (IHC) and MLH1 promoter methylation were repeated. In total, 86.9% of the 137 SLS tumors could be resolved into established subtypes. For 22.6% of these resolved SLS cases, primary MLH1 epimutations (2.2%) as well as previously undetected germline MMR pathogenic variants (1.5%), tumor MLH1 methylation (13.1%) or false positive dMMR IHC (5.8%) results were identified. Double somatic MMR gene mutations were the major cause of dMMR identified across each tumor type (73.9% of resolved cases, 64.2% overall, 70% of CRC, 45.5% of ECs and 70.8% of SSTs). The unresolved SLS tumors (13.1%) comprised tumors with only a single somatic (7.3%) or no somatic (5.8%) MMR gene mutations. A tumor-focused testing approach reclassified 86.9% of SLS into Lynch syndrome, sporadic dMMR or MMR-proficient cases. These findings support the incorporation of tumor sequencing and alternate MLH1 methylation assays into clinical diagnostics to reduce the number of SLS patients and provide more appropriate surveillance and screening recommendations.

Risk factors for metachronous colorectal cancer and advanced neoplasia following primary colorectal cancer: a systematic review and meta-analysis.

BACKGROUND: Identifying risk factors for metachronous colorectal cancer (CRC) and metachronous advanced neoplasia could be useful for guiding surveillance. We conducted a systematic review and meta-analysis to investigate risk factors for metachronous CRC and advanced neoplasia. METHODS: Searches were conducted in MEDLINE, Embase, Web of Science and Cochrane Central Registry of Controlled Trials for articles (searching period: 1945 to Feburary, 2021) that reported the results of an association between any factor and metachronous advanced neoplasia or metachronous CRC. There were no restrictions on the publication date or language. Random effects models were fitted to estimate the combined association between the risk factors and metachronous CRC or advanced neoplasia. The Risk of Bias In Non-Randomised Studies of Interventions tool (ROBINS-I) was used to assess the risk of bias of included studies. RESULTS: In total, 22 observational studies with 625,208 participants were included in the systematic review and meta-analysis. Of these, 13 studies investigated risk factors for metachronous CRC and 9 for advanced neoplasia. The risks of metachronous CRC or advanced neoplasia were higher if the first CRC was diagnosed in the presence of a synchronous advanced lesion (pooled risk ratio (RR) from 3 studies: 3.61, 95% confidence interval (CI): 1.44-9.05; and pooled RR from 8 studies: 2.77, 95% CI: 2.23-3.43, respectively). The risk of metachronous CRC was lower, but the risk of metachronous advanced neoplasia was higher if the first CRC was distal (compared with proximal) (pooled RR from 3 studies: 0.48, 95% CI: 0.23-0.98; and pooled RR from 2 studies: 2.99, 95% CI: 1.60-5.58 respectively). The risk of metachronous advanced neoplasia increased with age (pooled RR from 3 studies: 1.07 per year of age, 95% CI: 1.03-1.11). There was no evidence that any lifestyle risk factors studied were associated with the risk of metachronous CRC or advanced neoplasia. CONCLUSIONS: The identified risk factors for metachronous CRC and advanced neoplasia might be useful to tailor the existing surveillance guidelines after the first CRC. There were potential limitations due to possible misclassification of the outcome, confounding and risk of bias, and the findings cannot be generalised to high-risk genetic syndrome cases.

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.

The predicted effect and cost-effectiveness of tailoring colonoscopic surveillance according to mismatch repair gene in patients with Lynch syndrome.

PURPOSE: Lynch syndrome-related colorectal cancer (CRC) risk substantially varies by mismatch repair (MMR) gene. We evaluated the health impact and cost-effectiveness of MMR gene-tailored colonoscopic surveillance. METHODS: We first estimated sex- and MMR gene-specific cumulative lifetime risk of first CRC without colonoscopic surveillance using an optimization algorithm. Next, we harnessed these risk estimates in a microsimulation model, "Policy1-Lynch," and compared 126 colonoscopic surveillance strategies against no surveillance. RESULTS: The most cost-effective strategy was 3-yearly surveillance from age 25 to 70 years (pathogenic variants [path_] in MLH1 [path_MLH1], path_MSH2) with delayed surveillance for path_MSH6 (age 30-70 years) and path_PMS2 (age 35-70 years) heterozygotes (incremental cost-effectiveness ratio = Australian dollars (A) $8,833/life-year saved). This strategy averted 60 CRC deaths (153 colonoscopies per death averted) over the lifetime of 1000 confirmed patients with Lynch syndrome (vs no surveillance). This also reduced colonoscopies by 5% without substantial change in health outcomes (vs nontailored 3-yearly surveillance from 25-70 years). Generally, starting surveillance at age 25 (vs 20) years was more cost-effective with minimal effect on life-years saved and starting 5 to 10 years later for path_MSH6 and path_PMS2 heterozygotes (vs path_MLH1 and path_MSH2) further improved cost-effectiveness. Surveillance end age (70/75/80 years) had a minor effect. Three-yearly surveillance strategies were more cost-effective (vs 1 or 2-yearly) but prevented 3 fewer CRC deaths. CONCLUSION: MMR gene-specific colonoscopic surveillance would be effective and cost-effective.

Diet and risk of Barrett's oesophagus: Melbourne collaborative cohort study.

Barrett's oesophagus (BE) is the precursor of oesophageal adenocarcinoma, which has become the most common type of oesophageal cancer in many Western populations. Existing evidence on diet and risk of BE predominantly comes from case-control studies, which are subject to recall bias in measurement of diet. We aimed to investigate the potential effect of diet, including macronutrients, carotenoids, food groups, specific food items, beverages and dietary scores, on risk of BE in over 20 000 participants of the Melbourne Collaborative Cohort Study. Diet at baseline (1990-1994) was measured using a food frequency questionnaire. The outcome was BE diagnosed between baseline and follow-up (2007-2010). Logistic regression models were used to estimate OR and 95 % CI for diet in relation to risk of BE. Intakes of leafy vegetables and fruit were inversely associated with risk of BE (highest v. lowest quartile: OR = 0·59; CI: 0·38, 0·94; P-trend = 0·02 and OR = 0·58; CI: 0·37, 0·93; P-trend = 0·02 respectively), as were dietary fibre and carotenoids. Stronger associations were observed for food than the nutrients found in them. Positive associations were observed for discretionary food (OR = 1·54; CI: 0·97, 2·44; P-trend = 0·04) and total fat intake (OR per 10 g/d = 1·11; CI: 1·00, 1·23), the association for fat was less robust in sensitivity analyses. No association was observed for meat, protein, dairy products or diet scores. Diet is a potential modifiable risk factor for BE. Public health and clinical guidelines that incorporate dietary recommendations could contribute to reduction in risk of BE and, thereby, oesophageal adenocarcinoma.

CD10 and Das1: a biomarker study using immunohistochemistry to subtype gastric intestinal metaplasia.

BACKGROUND: Intestinal metaplasia (IM) is considered a key pivot point in the Correa model of gastric cancer (GC). It is histologically subtyped into the complete and incomplete subtypes, the latter being associated with a greater risk of progression. However, the clinical utility of IM subtyping remains unclear, partially due to the absence of reliable defining biomarkers. METHODS: Based on gene expression data and existing literature, we selected CD10 and Das1 as candidate biomarkers to distinguish complete and incomplete IM glands in tissues from patients without GC (IM-GC) and patients with GC (IM + GC). Immunohistochemical staining of individually subtyped IM glands was scored after blinding by two researchers using tissue belonging to both IM-GC and IM + GC patients. Whole tissue Das1 staining was further assessed using digital image quantification (cellSens Dimension, Olympus). RESULTS: Across both cohorts CD10 stained the IM brush border and was shown to have a high sensitivity (87.5% and 94.9% in IM-GC and IM + GC patients respectively) and specificity (100.0% and 96.7% respectively) with an overall AUROC of 0.944 for complete IM glands. By contrast Das1 stained mainly goblet cells and the apical membrane of epithelial cells, mostly of incomplete IM glands with a low sensitivity (28.6% and 29.3% in IM-GC and IM + GC patients respectively) but high specificity (98.3% and 85.1% respectively) and an overall AUROC of 0.603 for incomplete IM glands. A combined logistic regression model showed a significant increase in AUROC for detecting complete IM glands (0.955 vs 0.970). Whole tissue digital quantification of Das1 staining showed a significant association with incomplete IM compared to complete IM, both in IM-GC and in IM + GC patients (p = 0.016 and p = 0.009 respectively, Mann-Whitney test and unpaired t test used). Additionally, complete IM in IM + GC patients exhibited significantly more Das1 staining than in IM-GC patients (p = 0.019, Mann-Whitney test). CONCLUSIONS: These findings suggest that CD10 is an outstanding biomarker for complete IM and Das1 may be useful as a secondary biomarker for IM glands at greater risk of progression irrespective of IM subtype. Overall, the clinical use of these biomarkers could lead to improved patient stratification and targeted surveillance.

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.

SFRP4 drives invasion in gastric cancer and is an early predictor of recurrence.

OBJECTIVE: Gastric cancer patients generally have a poor outcome, particularly those with advanced-stage disease which is defined by the increased invasion of cancer locally and is associated with higher metastatic potential. This study aimed to identify genes that were functional in the most fundamental hallmark of cancer, namely invasion. We then wanted to assess their value as biomarkers of gastric cancer progression and recurrence. DESIGN: Data from a cohort of patients profiled on cDNA expression arrays was interrogated using K-means analysis. This genomic approach classified the data based on patterns of gene expression allowing the identification of the genes most correlated with the invasion of GC. We evaluated the functional role of a key protein from this analysis in invasion and as a biomarker of recurrence after curative resection. RESULTS: Expression of secreted frizzled-related protein 4 (SFRP4) was identified as directly proportional to gastric cancer invasion. This finding was validated in multiple, independent datasets and its functional role in invasion was also confirmed using invasion assays. A change in serum levels of SFRP4 after curative resection, when coupled with AJCC stage, can accurately predict the risk of disease recurrence after curative therapy in an assay we termed PredictR. CONCLUSIONS: This simple ELISA-based assay can help predict recurrence of disease after curative gastric cancer surgery irrespective of adjuvant therapy. The results require further evaluation in a prospective trial but would help in the rational prescription of cancer therapies and surveillance to prevent under or over treatment of patients after curative resection.

Diet and risk of gastro-oesophageal reflux disease in the Melbourne Collaborative Cohort Study.

OBJECTIVE: To examine associations between diet and risk of developing gastro-oesophageal reflux disease (GERD). DESIGN: Prospective cohort with a median follow-up of 15·8 years. Baseline diet was measured using a FFQ. GERD was defined as self-reported current or history of daily heartburn or acid regurgitation beginning at least 2 years after baseline. Sex-specific logistic regressions were performed to estimate OR for GERD associated with diet quality scores and intakes of nutrients, food groups and individual foods and beverages. The effect of substituting saturated fat for monounsaturated or polyunsaturated fat on GERD risk was examined. SETTING: Melbourne, Australia. PARTICIPANTS: A cohort of 20 926 participants (62 % women) aged 40-59 years at recruitment between 1990 and 1994. RESULTS: For men, total fat intake was associated with increased risk of GERD (OR 1·05 per 5 g/d; 95 % CI 1·01, 1·09; P = 0·016), whereas total carbohydrate (OR 0·89 per 30 g/d; 95 % CI 0·82, 0·98; P = 0·010) and starch intakes (OR 0·84 per 30 g/d; 95 % CI 0·75, 0·94; P = 0·005) were associated with reduced risk. Nutrients were not associated with risk for women. For both sexes, substituting saturated fat for polyunsaturated or monounsaturated fat did not change risk. For both sexes, fish, chicken, cruciferous vegetables and carbonated beverages were associated with increased risk, whereas total fruit and citrus were associated with reduced risk. No association was observed with diet quality scores. CONCLUSIONS: Diet is a possible risk factor for GERD, but food considered as triggers of GERD symptoms might not necessarily contribute to disease development. Potential differential associations for men and women warrant further investigation.

Hereditary diffuse gastric cancer: updated clinical practice guidelines.

Hereditary diffuse gastric cancer (HDGC) is an autosomal dominant cancer syndrome that is characterised by a high prevalence of diffuse gastric cancer and lobular breast cancer. It is largely caused by inactivating germline mutations in the tumour suppressor gene CDH1, although pathogenic variants in CTNNA1 occur in a minority of families with HDGC. In this Policy Review, we present updated clinical practice guidelines for HDGC from the International Gastric Cancer Linkage Consortium (IGCLC), which recognise the emerging evidence of variability in gastric cancer risk between families with HDGC, the growing capability of endoscopic and histological surveillance in HDGC, and increased experience of managing long-term sequelae of total gastrectomy in young patients. To redress the balance between the accessibility, cost, and acceptance of genetic testing and the increased identification of pathogenic variant carriers, the HDGC genetic testing criteria have been relaxed, mainly through less restrictive age limits. Prophylactic total gastrectomy remains the recommended option for gastric cancer risk management in pathogenic CDH1 variant carriers. However, there is increasing confidence from the IGCLC that endoscopic surveillance in expert centres can be safely offered to patients who wish to postpone surgery, or to those whose risk of developing gastric cancer is not well defined.

The predicted impact and cost-effectiveness of systematic testing of people with incident colorectal cancer for Lynch syndrome.

OBJECTIVES: To evaluate the health impact and cost-effectiveness of systematic testing for Lynch syndrome (LS) in people with incident colorectal cancer (CRC) in Australia. DESIGN, SETTING, PARTICIPANTS: We investigated the impact of LS testing strategies in a micro-simulation model (Policy1-Lynch), explicitly modelling the cost of testing all patients diagnosed with incident CRC during 2017, with detailed modelling of outcomes for patients identified as LS carriers (probands) and their at-risk relatives throughout their lifetimes. For people with confirmed LS, we modelled ongoing colonoscopic surveillance. MAIN OUTCOME MEASURES: Cost-effectiveness of six universal tumour testing strategies (testing for DNA mismatch repair deficiencies) and of universal germline gene panel testing of patients with incident CRC; impact on cost-effectiveness of restricting testing by age at CRC diagnosis (all ages, under 50/60/70 years) and of colonoscopic surveillance interval (one, two years). RESULTS: The cost-effectiveness ratio of universal tumour testing strategies (annual colonoscopic surveillance, no testing age limit) compared with no testing ranged from $28 915 to $31 904/life-year saved (LYS) (indicative willingness-to-pay threshold: $30 000-$50 000/LYS). These strategies could avert 184-189 CRC deaths with an additional 30 597-31 084 colonoscopies over the lifetimes of 1000 patients with incident CRC with LS and 1420 confirmed LS carrier relatives (164-166 additional colonoscopies/death averted). The most cost-effective strategy was immunohistochemistry and BRAF V600E testing (incremental cost-effectiveness ratio [ICER], $28 915/LYS). Universal germline gene panel testing was not cost-effective compared with universal tumour testing strategies (ICER, $2.4 million/LYS). Immunohistochemistry and BRAF V600E testing was cost-effective at all age limits when paired with 2-yearly colonoscopic surveillance (ICER, $11 525-$32 153/LYS), and required 4778-15 860 additional colonoscopies to avert 46-181 CRC deaths (88-103 additional colonoscopies/death averted). CONCLUSIONS: Universal tumour testing strategies for guiding germline genetic testing of people with incident CRC for LS in Australia are likely to be cost-effective compared with no testing. Universal germline gene panel testing would not currently be cost-effective.

Point Mutations in Exon 1B of APC Reveal Gastric Adenocarcinoma and Proximal Polyposis of the Stomach as a Familial Adenomatous Polyposis Variant.

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is an autosomal-dominant cancer-predisposition syndrome with a significant risk of gastric, but not colorectal, adenocarcinoma. We mapped the gene to 5q22 and found loss of the wild-type allele on 5q in fundic gland polyps from affected individuals. Whole-exome and -genome sequencing failed to find causal mutations but, through Sanger sequencing, we identified point mutations in APC promoter 1B that co-segregated with disease in all six families. The mutations reduced binding of the YY1 transcription factor and impaired activity of the APC promoter 1B in luciferase assays. Analysis of blood and saliva from carriers showed allelic imbalance of APC, suggesting that these mutations lead to decreased allele-specific expression in vivo. Similar mutations in APC promoter 1B occur in rare families with familial adenomatous polyposis (FAP). Promoter 1A is methylated in GAPPS and sporadic FGPs and in normal stomach, which suggests that 1B transcripts are more important than 1A in gastric mucosa. This might explain why all known GAPPS-affected families carry promoter 1B point mutations but only rare FAP-affected families carry similar mutations, the colonic cells usually being protected by the expression of the 1A isoform. Gastric polyposis and cancer have been previously described in some FAP-affected individuals with large deletions around promoter 1B. Our finding that GAPPS is caused by point mutations in the same promoter suggests that families with mutations affecting the promoter 1B are at risk of gastric adenocarcinoma, regardless of whether or not colorectal polyps are present.

Safety and Acceptability of Esophageal Cytosponge Cell Collection Device in a Pooled Analysis of Data From Individual Patients.

BACKGROUND & AIMS: Diagnosis and surveillance of Barrett's esophagus (BE) and eosinophilic esophagitis (EoE) have become emerging public health issues. Cytosponge is a novel, minimally invasive esophageal cell collection device. We aimed to assess the data on safety and acceptability of this device. METHODS: We performed a patient-level review of 5 prospective trials assessing Cytosponge performance in patients with reflux disease, BE and EoE in primary and secondary care. Acceptability of Cytosponge and subsequent endoscopy were recorded with visual analogue scale (VAS), wherein 0 and 10 denoted lowest and highest acceptability. Median VAS scores were compared using a Mann-Whitney test. The number of attempts, failures in swallowing the device and occurrence of adverse events were analyzed. Risk factors for failure in swallowing were analyzed using a multivariate regression model. RESULTS: In total, 2672 Cytosponge procedures were performed, in 2418 individuals from 2008 through 2017. There were 2 adverse events related to the device: a minor pharyngeal bleed and a case of detachment (<1:2000). The median acceptability score for the Cytosponge was 6.0 (interquartile range [IQR], 5.0-8.0), which was higher than the score for endoscopy without sedation (median 5.0; IQR, 3.0-7.0; P < .001) and lower than the score for endoscopy with sedation (median 8.0; IQR, 5.0-9.0; P < .001). Nearly all patients (91.1%) successfully swallowed the Cytosponge, most on the first attempt (90.1%). Failure to swallow the device was more likely to occur in secondary care (odds ratio, 5.13; 95% CI, 1.48-17.79; P < .01). CONCLUSIONS: The Cytosponge test is a safe procedure with good acceptability ratings in a variety of health care settings.

Dietary Intake of Nutrients Involved in One-Carbon Metabolism and Risk of Gastric Cancer: A Prospective Study.

Dietary intakes of B vitamins and other components involved in one-carbon metabolism, which is necessary for DNA replication, DNA repair, and regulation of gene expression, may be associated with carcinogenesis. We investigated associations between intakes of 11 nutrients (thiamine, riboflavin, niacin, pantothenic acid, vitamin B6, biotin, folate, vitamin B12, methionine, choline, and betaine) and gastric cancer risk. A total of 159 incident gastric cancer cases were identified from the Melbourne Collaborative Cohort Study (N = 41,513) and matched with 159 controls on year of birth, sex, and country of birth using incidence density sampling. Dietary intakes of nutrients were estimated at baseline (1990-1994) using a 121-item food frequency questionnaire. Odds ratios (ORs) and 95% confidence intervals were estimated using conditional logistic regression models adjusting for Helicobacter pylori infection, and other potential confounders. We observed a positive association between intake of niacin and overall gastric cancer risk (OR = 1.33, 95%CI: 1.01-1.75 per SD increment). For thiamine, heterogeneity by subtype (cardia and non-cardia) was found (Phet = 0.05), with weak evidence of an inverse association with cardia cancer risk. Our results do not support increasing intakes of B vitamins or other nutrients involved in one-carbon metabolism to reduce gastric cancer risk in a well-nourished population.

Family history-based colorectal cancer screening in Australia: A modelling study of the costs, benefits, and harms of different participation scenarios.

BACKGROUND: The Australian National Bowel Cancer Screening Programme (NBCSP) was introduced in 2006. When fully implemented, the programme will invite people aged 50 to 74 to complete an immunochemical faecal occult blood test (iFOBT) every 2 years. METHODS AND FINDINGS: To investigate colorectal cancer (CRC) screening occurring outside of the NBCSP, we classified participants (n = 2,480) in the Australasian Colorectal Cancer Family Registry (ACCFR) into 3 risk categories (average, moderately increased, and potentially high) based on CRC family history and assessed their screening practices according to national guidelines. We developed a microsimulation to compare hypothetical screening scenarios (70% and 100% uptake) to current participation levels (baseline) and evaluated clinical outcomes and cost for each risk category. The 2 main limitations of this study are as follows: first, the fact that our cost-effectiveness analysis was performed from a third-party payer perspective, which does not include indirect costs and results in overestimated cost-effectiveness ratios, and second, that our natural history model of CRC does not include polyp sojourn time, which determines the rate of cancerous transformation. Screening uptake was low across all family history risk categories (64%-56% reported no screening). For participants at average risk, 18% reported overscreening, while 37% of those in the highest risk categories screened according to guidelines. Higher screening levels would substantially reduce CRC mortality across all risk categories (95 to 305 fewer deaths per 100,000 persons in the 70% scenario versus baseline). For those at average risk, a fully implemented NBCSP represented the most cost-effective approach to prevent CRC deaths (AUS$13,000-16,000 per quality-adjusted life year [QALY]). For those at moderately increased risk, higher adherence to recommended screening was also highly cost-effective (AUS$19,000-24,000 per QALY). CONCLUSION: Investing in public health strategies to increase adherence to appropriate CRC screening will save lives and deliver high value for money.

Revised Australian national guidelines for colorectal cancer screening: family history.

INTRODUCTION: Screening is an effective means for colorectal cancer prevention and early detection. Family history is strongly associated with colorectal cancer risk. We describe the rationale, evidence and recommendations for colorectal cancer screening by family history for people without a genetic syndrome, as reported in the 2017 revised Australian guidelines. Main recommendations: Based on 10-year risks of colorectal cancer, people at near average risk due to no or weak family history (category 1) are recommended screening by immunochemical faecal occult blood test (iFOBT) every 2 years from age 50 to 74 years. Individuals with moderate risk due to their family history (category 2) are recommended biennial iFOBT from age 40 to 49 years, then colonoscopy every 5 years from age 50 to 74 years. People with a high risk due to their family history (category 3) are recommended biennial iFOBT from age 35 to 44 years, then colonoscopy every 5 years from age 45 to 74 years. Changes in management as a result of the guidelines: By 2019, the National Bowel Cancer Screening Program will offer all Australians free biennial iFOBT screening from age 50 to 74 years, consistent with the recommendations in these guidelines for category 1. Compared with the 2005 guidelines, there are some minor changes in the family history inclusion criteria for categories 1 and 2; the genetic syndromes have been removed from category 3 and, as a consequence, colonoscopy screening is now every 5 years; and for categories 2 and 3, screening begins with iFOBT for people aged 40 and 35 years, respectively, before transitioning to colonoscopy after 10 years.