Cell division-dependent dissemination following E-cadherin loss underlies initiation of diffuse-type gastric cancer.

Loss of the cell-cell adhesion protein E-cadherin underlies the development of diffuse-type gastric cancer (DGC), which is characterized by the gradual accumulation of tumor cells originating from the gastric epithelium in the surrounding stroma. How E-cadherin deficiency drives DGC formation remains elusive. Therefore, we investigated the consequences of E-cadherin loss on gastric epithelial organization utilizing a human gastric organoid model and histological analyses of early-stage DGC lesions. E-cadherin depletion from gastric organoids recapitulates DGC initiation, with progressive loss of a single-layered architecture and detachment of individual cells. We found that E-cadherin deficiency in gastric epithelia does not lead to a general loss of epithelial cohesion but disrupts the spindle orientation machinery. This leads to a loss of planar cell division orientation and, consequently, daughter cells are positioned outside of the gastric epithelial layer. Although basally delaminated cells fail to detach and instead reintegrate into the epithelium, apically mispositioned daughter cells can trigger the gradual loss of the single-layered epithelial architecture. This impaired architecture hampers reintegration of mispositioned daughter cells and enables basally delaminated cells to disseminate into the surrounding matrix. Taken together, our findings describe how E-cadherin deficiency disrupts gastric epithelial architecture through displacement of dividing cells and provide new insights in the onset of DGC. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Nonsteroidal anti-inflammatory drugs before endoscopic ultrasound guided tissue acquisition to reduce the incidence of post procedural pancreatitis.

Endoscopic ultrasound (EUS) with fine needle aspiration or fine needle biopsy is the gold standard for sampling tissue to diagnose pancreatic cancer and autoimmune pancreatitis or to analyze cyst fluid. The most common reported adverse event of fine needle aspiration and/or fine needle biopsy is acute pancreatitis, which is likely induced by the same pathophysiological mechanisms as after endoscopic retrograde cholangiopancreatography (ERCP). According to the current European Society of Gastrointestinal Endoscopy guideline, nonsteroidal anti-inflammatory drugs are administered prior to ERCP as a scientifically proven treatment to reduce post-ERCP pancreatitis incidence rate. A single suppository of diclofenac or indomethacin prior to EUS guided tissue acquisition (TA) is harmless in healthy adults. Since it is associated with low costs and, most important, may prevent a dreadsome complication, we strongly recommend the administration of 100 mg diclofenac rectally prior to EUS-TA. We will explain this recommendation in more detail in this review as well as the risk and pathophysiology of post-EUS TA pancreatitis.

Gastric and duodenal cancer in individuals with Lynch syndrome: a nationwide cohort study.

Background: Lynch syndrome increases the risk of gastric cancer (GC) and duodenal cancer (DC), particularly in individuals with MLH1 and MSH2 pathogenic variants (PVs). To provide further insight into whether, and from what age, esophagogastroduodenoscopy (EGD) surveillance may be beneficial, we evaluated the cumulative incidence and tumour characteristics of GC and DC in a large nationwide cohort of Dutch individuals with LS. Methods: For this retrospective nationwide cohort study, clinical data of individuals with LS registered at the Dutch Hereditary Cancer Registry were matched with pathology reports filed by the Dutch Pathology registry. All individuals registered between Jan 1, 1989 and Dec 31, 2021 with proven or putative PVs in one of the mismatch repair genes were included. Cumulative incidences of GC and DC were estimated for high-risk (MLH1, MSH2 and EpCAM) and low-risk (MSH6 and PMS2) PVs using competing risk methodology (Fine and Gray method) with death due to other causes as competing risk. Findings: Among 1002 individuals with high-risk and 765 individuals with low-risk PVs, 29 GCs (1.6%) and 39 DCs (2.2%) were diagnosed. Cumulative incidence of GC and DC under the age of 50 was very low (≤1%) for all individuals. At age 70 and 75, cumulative incidence of GC was 3% [95% CI 1%-5%] and 5% [3%-8%] for high-risk PVs and 1% [0%-2%] and 1% [0%-2%] for low-risk PVs (p = 0.006). For DC, cumulative incidence at age 70 and 75 was 5% [3%-7%] and 6% [3%-8%] in high-risk, 1% [0%-1%] and 2% [0%-4%] in low-risk PVs, respectively (p = 0.01). Primary tumour resection was performed in 62% (18/29) of GCs and 77% (30/39) of DC cases. Early-stage GC, defined as TNM stage I, was found in 32% (9/28) of GCs. Early-stage DC, defined as TNM stage I-IIa, was found in 39% (14/36) of DCs. Interpretation: Individuals with MLH1, MSH2, and EpCAM PVs have an increased risk of developing GC and DC at the age of 70 years, but this risk is very low before the age of 50 years. The age of onset of surveillance, the yield of GC and DC during EGD surveillance, and its cost-effectiveness should be subject of future studies. Funding: None.

The influence of Helicobacter pylori, proton pump inhibitor, and obesity on the gastric microbiome in relation to gastric cancer development.

Helicobacter pylori infection is still the main risk factor for the development of gastric cancer (GC). We explore the scientific evidence for the role of the gastric microbiome beyond Helicobacter pylori (H. pylori) in gastric carcinogenesis. The composition of the gastric microbiome in healthy individuals, in presence and absence of H. pylori infection, in proton pump inhibitor (PPI)-users, obese individuals, and GC patients was investigated. Possible mechanisms for microbial involvement, limitations of available research and options for future studies are provided. A common finding amongst studies was increased levels of Streptococcus, Prevotella, Neisseria, and Actinomyces in healthy individuals or those with H. pylori-negative gastritis. In PPI-users the risk for GC increases with the treatment duration, and the gastric microbiome shifts, with the most consistent increase in the genus Streptococcus. Similarly, in obese individuals, Streptococcus was the most abundant genus, with an increased risk for cardia GC. The genera Streptococcus, Lactobacillus and Prevotella were found to be more prominent in GC patients in multiple studies. Potential mechanisms of non-H. pylori microbiota contributing to GC are linked to lipopolysaccharide production, contribution to inflammatory pathways, and the formation of N-nitroso compounds and reactive oxygen species. In conclusion, the knowledge of the gastric microbiome in GC is mainly descriptive and based on sequencing of gastric mucosal samples. For a better mechanistic understanding of microbes in GC development, longitudinal cohorts including precancerous lesions, different regions in the stomach, and subtypes of GC, and gastric organoid models for diffuse and intestinal type GC should be employed.

Prevalence of neoplasia at colonoscopy among testicular cancer survivors treated with platinum-based chemotherapy.

Testicular cancer survivors (TCS) treated with platinum-based chemotherapy have an increased risk of colorectal cancer (CRC). We determined the yield of colonoscopy in TCS to assess its potential in reducing CRC incidence and mortality. We conducted a colonoscopy screening study among TCS in four Dutch hospitals to assess the yield of colorectal neoplasia. Neoplasia was defined as adenomas, serrated polyps (SPs), advanced adenomas (AAs: ≥10 mm diameter, high-grade dysplasia or ≥25% villous component), advanced serrated polyps (ASPs: ≥10 mm diameter or dysplasia) or CRC. Advanced neoplasia (AN) was defined as AA, ASP or CRC. Colonoscopy yield was compared to average-risk American males who underwent screening colonoscopy (n = 24,193) using a propensity score matched analysis, adjusted for age, smoking status, alcohol consumption and body mass index. A total of 137 TCS underwent colonoscopy. Median age was 50 years among TCS (IQR 43-57) vs 55 years (IQR 51-62) among American controls. A total of 126 TCS were matched to 602 controls. The prevalence of AN was higher in TCS than in controls (8.7% vs 1.7%; P = .0002). Nonadvanced adenomas and SPs were detected in 45.2% of TCS vs 5.5% of controls (P < .0001). No lesions were detected in 46.0% of TCS vs 92.9% of controls (P < .0001). TCS treated with platinum-based chemotherapy have a higher prevalence of neoplasia and AN than matched controls. These results support our hypothesis that platinum-based chemotherapy increases the risk of colorectal neoplasia in TCS. Cost-effectiveness studies are warranted to ascertain the threshold of AN prevalence that justifies the recommendation of colonoscopy for TCS.

Diagnostic accuracy of endoscopic ultrasonography-guided tissue acquisition prior to resection of pancreatic carcinoma: a nationwide analysis.

INTRODUCTION: Endoscopic ultrasonography guided tissue acquisition (EUS + TA) is used to provide a tissue diagnosis in patients with suspected pancreatic cancer. Key performance indicators (KPI) for these procedures are rate of adequate sample (RAS) and sensitivity for malignancy (SFM). AIM: assess practice variation regarding KPI of EUS + TA prior to resection of pancreatic carcinoma in the Netherlands. PATIENTS AND METHODS: Results of all EUS + TA prior to resection of pancreatic carcinoma from 2014-2018, were extracted from the national Dutch Pathology Registry (PALGA). Pathology reports were classified as: insufficient for analysis (b1), benign (b2), atypia (b3), neoplastic other (b4), suspected malignant (b5), and malignant (b6). RAS was defined as the proportion of EUS procedures yielding specimen sufficient for analysis. SFM was calculated using a strict definition (malignant only, SFM-b6), and a broader definition (SFM-b5+6). RESULTS: 691 out of 1638 resected patients (42%) underwent preoperative EUS + TA. RAS was 95% (range 89-100%), SFM-b6 was 44% (20-77%), and SFM-b5+6 was 65% (53-90%). All centers met the performance target RAS>85%. Only 9 out of 17 met the performance target SFM-b5+6 > 85%. CONCLUSION: This nationwide study detected significant practice variation regarding KPI of EUS + TA procedures prior to surgical resection of pancreatic carcinoma. Therefore, quality improvement of EUS + TA is indicated.

[The influence of ultra-processed food on cardiovascular disease: how "why do things the hard way?" makes our brains soft]. / De invloed van sterk bewerkte voeding op hart- en vaatziekten.

Buying and consuming ultra-processed food makes life easy. Nowadays, there is more and more prove that the consumption of this food is associated with morbidity and mortality, e.g. cardiovascular disease, diabetes, neurocognitive diseases and cancer. Recently, Bonaccio et al. strenghtened this in a large prospective cohort for cardiovascular disease. They used among others the 'Nutri-Score' for their analysis. However, the reliability of this score remains under debate, and therefore, it is not the best to use as label for consumers. In short: although consumption of ultra-processed food is a risk factor for cardiovascular and other diseases, for consumers is remains difficult to recognize the healthiest food in the supermarket. What's in this for you, doc? Keep this in mind during your all-day practice and guide your patients to healthier foods during their consultation with you.

Cost-Effectiveness of Colorectal Cancer Surveillance in Hodgkin Lymphoma Survivors Treated with Procarbazine and/or Infradiaphragmatic Radiotherapy.

BACKGROUND: Hodgkin lymphoma survivors treated with infradiaphragmatic radiotherapy (IRT) and/or procarbazine have an increased risk of developing colorectal cancer. We investigated the cost-effectiveness of colorectal cancer surveillance in Dutch Hodgkin lymphoma survivors to determine the optimal surveillance strategy for different Hodgkin lymphoma subgroups. METHODS: The Microsimulation Screening Analysis-Colon model was adjusted to reflect colorectal cancer and other-cause mortality risk in Hodgkin lymphoma survivors. Ninety colorectal cancer surveillance strategies were evaluated varying in starting and stopping age, interval, and modality [colonoscopy, fecal immunochemical test (FIT, OC-Sensor; cutoffs: 10/20/47 µg Hb/g feces), and multi-target stool DNA test (Cologuard)]. Analyses were also stratified per primary treatment (IRT and procarbazine or procarbazine without IRT). Colorectal cancer deaths averted (compared with no surveillance) and incremental cost-effectiveness ratios (ICER) were primary outcomes. The optimal surveillance strategy was identified assuming a willingness-to-pay threshold of €20,000 per life-years gained (LYG). RESULTS: Overall, the optimal surveillance strategy was annual FIT (47 µg) from age 45 to 70 years, which might avert 70% of colorectal cancer deaths in Hodgkin lymphoma survivors (compared with no surveillance; ICER:€18,000/LYG). The optimal surveillance strategy in Hodgkin lymphoma survivors treated with procarbazine without IRT was biennial FIT (47 µg) from age 45 to 70 years (colorectal cancer mortality averted 56%; ICER:€15,000/LYG), and when treated with IRT and procarbazine, annual FIT (47 µg) surveillance from age 40 to 70 was most cost-effective (colorectal cancer mortality averted 75%; ICER:€13,000/LYG). CONCLUSIONS: Colorectal cancer surveillance in Hodgkin lymphoma survivors is cost-effective and should commence earlier than screening occurs in population screening programs. For all subgroups, FIT surveillance was the most cost-effective strategy. IMPACT: Colorectal cancer surveillance should be implemented in Hodgkin lymphoma survivors.

Detection and Yield of Colorectal Cancer Surveillance in Adults with PTEN Hamartoma Tumour Syndrome.

Colorectal cancer surveillance (CCS) with colonoscopy every five years is advised for PTEN Hamartoma Tumour Syndrome (PHTS) patients aged ≥40 due to an increased colorectal cancer (CRC) risk. However, data to support CCS guidelines are scarce and available CRC risks are low (0-5% at age 50) and likely overestimated. We aimed to assess the detection and yield of CCS for PHTS patients without a CRC history. A retrospective cohort study including PHTS patients aged ≥40 with CCS at a PHTS expertise centre between 2011 and 2022. Adenomas with a ≥10 mm size, (tubulo)villous histology, or high-grade dysplasia were considered advanced. During 67 follow-up years, 37 patients (median age 47 years) underwent 61 colonoscopies. CCS yielded no CRCs. Adenomas were diagnosed in 13/37 (35%) patients during 23/100 colonoscopies (95% CI: 14-36), including one advanced adenoma. Baseline adenoma detection rates were similar to follow-up and higher in patients aged above 50 (50/100, 95% CI: 24-76) vs. age 50 or below (11/100, 95% CI: 3-30; p = 0.021). The low CRC and advanced adenoma yield allow for a more personalised surveillance program. Following our findings combined with literature on CRC risk and progression, we suggest starting CCS at age 40 with variable follow-up intervals between 1 and 10 years depending on previous colonoscopy findings.

International Delphi consensus guidelines for follow-up after prophylactic total gastrectomy: the Life after Prophylactic Total Gastrectomy (LAP-TG) study.

BACKGROUND: Prophylactic total gastrectomy (PTG) remains the only means of preventing gastric cancer for people with genetic mutations predisposing to Hereditary Diffuse Gastric Cancer (HDGC), mainly in the CDH1 gene. The small but growing cohort of people undergoing PTG at a young age are expected to have a life-expectancy close to the general population, however, knowledge of the long-term effects of, and monitoring requirements after, PTG is limited. This study aims to define the standard of care for follow-up after PTG. METHODS: Through a combination of literature review and two-round Delphi consensus of major HDGC/PTG units and physicians, and patient advocates, we produced a set of recommendations for follow-up after PTG. RESULTS: There were 42 first round, and 62 second round, responses from clinicians, allied health professionals and patient advocates. The guidelines include recommendations for timing of assessments and specialties involved in providing follow-up, micronutrient supplementation and monitoring, bone health and the provision of written information. CONCLUSION: While the evidence supporting the guidelines is limited, expert consensus provides a framework to best manage people following PTG, and could support the collection of information on the long-term effects of PTG.

Bite-on-bite biopsies for the detection of residual esophageal cancer after neoadjuvant chemoradiotherapy.

BACKGROUND: Active surveillance after neoadjuvant treatment is increasingly implemented. The success of this strategy relies on the accurate detection of residual cancer. This study aimed to assess the diagnostic value of a second (bite-on-bite) biopsy for the detection of residual esophageal cancer and to correlate outcomes to the distribution of residual cancer found in the resection specimen. METHODS: A multicenter prospective study of esophageal cancer patients undergoing active surveillance after neoadjuvant chemoradiotherapy was performed. At clinical response evaluations, an upper gastrointestinal (GI) endoscopy was performed with at least four bite-on-bite biopsies of the primary tumor site. First and second biopsies were analyzed separately. Patients with histopathological evidence of residual cancer were included in the primary analysis. Two pathologists blinded for biopsy outcome examined all resection specimens. RESULTS: Between October 2017 and July 2020, 626 upper GI endoscopies were performed in 367 patients. Of 138 patients with residual cancer, 112 patients (81 %) had at least one positive biopsy. In 14 patients (10 %) only the first biopsy was positive and in 25 patients (18 %) only the second biopsy (P = 0.11). Remarkably, the rates of patients with tumor-free mucosa and deeper located tumors were higher in patients detected by the first biopsy. The second biopsy increased the false-positive rate by 3 percentage points. No adverse events occurred. CONCLUSIONS: A second (bite-on-bite) biopsy improves the detection of residual esophageal cancer by almost 20 percentage points, at the expense of increasing the false-positive rate by 3 percentage points. The higher detection rate is explained by the higher number of biopsies obtained rather than by the penetration depth.

Clinicopathological features and risk factors for developing colorectal neoplasia in Hodgkin's lymphoma survivors.

BACKGROUND: Hodgkin's lymphoma (HL) survivors treated with abdominal radiotherapy and/or procarbazine have an increased risk of developing colorectal neoplasia. AIMS: We evaluated the clinicopathological characteristics and risk factors for developing (advanced) neoplasia (AN) in HL survivors. METHODS: In all, 101 HL survivors (median age 51 years, median age of HL diagnosis 25 years) underwent colonoscopy and 350 neoplasia and 44 AN (classified as advanced adenomas/serrated lesions or colorectal cancer), mostly right-sided, were detected, as published previously. An average-risk asymptomatic cohort who underwent screening colonoscopy were controls (median age 60 years). Clinicopathological characteristics of AN were evaluated in both groups. Mismatch repair (MMR) status was assessed using immunohistochemistry (MLH1/MSH2/MSH6/PMS2). Logistic regression analysis was performed to evaluate the risk factors for AN in HL survivors, including age at HL diagnosis and interval between HL and colonoscopy. RESULTS: In 101 colonoscopies in HL survivors, AN was primarily classified based on polyp size ≥10 mm, whereas (high-grade)dysplasia was more often seen in AN in controls. An interval between HL diagnosis and colonoscopy >26 years was associated with more AN compared with an interval of <26 years, with an odds ratio for AN of 3.8 (95% confidence interval 1.4-9.1) (p < 0.01). All 39 AN that were assessed were MMR proficient. CONCLUSIONS: Colorectal neoplasia in HL survivors differ from average-risk controls; classification AN was primarily based on polyp size (≥10 mm) in HL survivors. Longer follow-up between HL diagnosis and colonoscopy was associated with a higher prevalence of AN in HL survivors.

The Workgroup Serrated Polyps and Polyposis (WASP) classification for optical diagnosis of colorectal diminutive polyps with iScan and the impact of the revised World Health Organization (WHO) criteria.

BACKGROUND AND AIMS: The Workgroup Serrated Polyps and Polyposis (WASP) developed criteria for optical diagnosis of colorectal polyps. The aims of this study were: (1) to improve optical diagnosis of diminutive colorectal polyps, especially SSLs, after training endoscopists in applying WASP criteria on videos of polyps obtained with iScan and (2) to evaluate if the WASP criteria are still useful when polyps are pathologically revised according to the World Health Organization (WHO) 2019 criteria. METHODS: Twenty-one endoscopists participated in a training session and predicted polyp histology on 30 videos of diminutive polyps, before and after training (T0 and T1 ). After three months, they scored another 30 videos (T2 ). Primary outcome was overall diagnostic accuracy (DA) at T0 , T1 and T2 . Polyps were histopathologically classified according to the WHO 2010 and 2019 criteria. RESULTS: Overall DA (both diminutive adenomas and SSLs) significantly improved from 0.58 (95% CI 0.55-0.62) at T0 to 0.63 (95% CI 0.60-0.66, p = 0.004) at T1 . For SSLs, DA did not change with 0.51 (95% CI 0.46-0.56) at T0 and 0.55 (95% CI 0.49-0.60, p = 0.119) at T1 . After three months, overall DA was 0.58 (95% CI 0.54-0.62, p = 0.787, relative to T0 ) while DA for SSLs was 0.48 (95% CI 0.42-0.55, p = 0.520) at T2 . After pathological revision according to the WHO 2019 criteria, DA of all polyps significantly changed at all time points. CONCLUSION: A training session in applying WASP criteria on endoscopic videos made with iScan did not improve endoscopists' long-term ability to optically diagnose diminutive polyps. The change of DA following polyp revision according to the revised WHO 2019 criteria suggests that the WASP classification may need revision.

Associations of Height With the Risks of Colorectal and Endometrial Cancer in Persons With Lynch Syndrome.

People with Lynch syndrome (LS), who carry a pathogenic mutation in a DNA mismatch repair gene, have increased risks of colorectal cancer (CRC) and endometrial cancer (EC). A high reported variability in cancer risk suggests the existence of factors that modify cancer risk for persons with LS. We aimed to investigate the associations between height and CRC and EC risk for persons with LS using data from 2 large studies. Information on 1,115 men and 1,553 women with LS from the Colon Cancer Family Registry (1998-2007) and the GEOLynch Cohort Study (2006-2017) was harmonized. We used weighted Cox proportional hazards regression models with age on the time axis to estimate adjusted hazard ratios and 95% confidence intervals for each 5-cm increment in self-reported height. CRC was diagnosed in 947 persons during 65,369 person-years of observation, and 171 women were diagnosed with EC during 39,227 person-years. Height was not associated with CRC for either men (per 5-cm increment, hazard ratio (HR) = 1.00, 95% confidence interval (CI): 0.91, 1.11) or women (per 5-cm increment, HR = 1.01, 95% CI: 0.92, 1.11), nor was height associated with EC (per 5-cm increment, HR = 1.08, 95% CI: 0.94, 1.24). Hence, we observed no evidence for an association of height with either CRC or EC among persons with LS.

Diagnostic yield of colonoscopy surveillance in testicular cancer survivors treated with platinum-based chemotherapy: study protocol of a prospective cross-sectional cohort study.

BACKGROUND: Testicular cancer (TC) survivors have an increased risk of various second primary malignancies. A recent cohort study detected an increased risk of colorectal cancer (CRC) in TC survivors treated with platinum-based chemotherapy with a hazard ratio of 3.9. CRC risk increased with higher cisplatin-dose. We know that colonoscopy surveillance in high-risk populations results in reduced incidence and mortality of CRC. TC survivors treated with platinum-based chemotherapy can potentially benefit from colonoscopy surveillance; however, to which extent is unknown. Furthermore, the pathogenesis of these secondary CRCs is unknown, and better insights into the carcinogenesis may affect surveillance decisions. METHODS: This prospective multicenter study will be performed in four Dutch hospitals. TC survivors are eligible if treated with ≥ 3 cycles of cisplatin before age 50. Colonoscopy will be performed ≥ 8 years after initial treatment (minimum and maximum ages at colonoscopy, 35 and 75 years, respectively). The primary aim of the study is the diagnostic yield of advanced neoplasia detected during colonoscopy. As secondary aim, we will evaluate the molecular profile of advanced colorectal neoplasia and will assess current platinum levels in blood and urine and correlate blood-platinum levels with prevalence of colorectal lesions. Furthermore, we will investigate effectiveness of fecal immunochemical testing (FIT) and burden of colonoscopy by two questionnaires. Demographic data, previous history, results of colonoscopy, hemoglobin level of FIT and results of molecular and platinum levels will be obtained. Yield of colonoscopy will be determined by detection rate of adenoma and serrated lesions, advanced adenoma detection rate and CRC detection rate. The MISCAN model will be used for cost-effectiveness analyses of CRC surveillance. With 234 participants undergoing colonoscopy, we can detect an absolute difference of 6% of advanced neoplasia with 80% power. DISCUSSION: TC survivors treated with cisplatin-based chemotherapy can benefit from CRC surveillance. Evaluation of the diagnostic performance and patient acceptance of CRC surveillance is of importance to develop surveillance recommendations. Insight into the carcinogenesis of cisplatin-related advanced colorectal lesions will contribute to CRC prevention in the increasing number of TC survivors. The results may also be important for the many other cancer survivors treated with platinum-based chemotherapy. TRIAL REGISTRATION: Clinical Trials: NCT04180033, November 27, 2019, https://clinicaltrials.gov/ct2/show/NCT04180033 .

RNF43 mutation analysis in serrated polyposis, sporadic serrated polyps and Lynch syndrome polyps.

AIMS: RNF43 is suggested to be involved in the serrated pathway towards colorectal cancer and encodes a transmembrane Ring-type E3 ubiquitin ligase that negatively regulates the Wnt pathway. This study aimed to elucidate the role of RNF43 gene variants in serrated polyposis syndrome (SPS) and serrated polyps. METHODS AND RESULTS: Three cohorts were tested. The first cohort included germline DNA of 26 SPS patients tested for pathogenic variants in RNF43 by Sanger sequencing all exons. In the second cohort we tested somatic DNA for RNF43 mutations from sporadic serrated lesions: 25 hyperplastic polyps, 35 sessile serrated lesions and 38 traditional serrated adenomas (TSA). In the third cohort we investigated RNF43 mutations in 49 serrated polyps and 60 conventional adenomas from 40 patients with Lynch syndrome. No germline RNF43 pathogenic variants were detected in our SPS cohort. In sporadic colorectal lesions we detected RNF43 deleterious frameshift mutations in three TSA and one SSL. The RNF43 mutations in previously described homopolymeric hot-spots were detected in microsatellite-instable (MSI) polyps and the other RNF43 mutations in microsatellite-stable (MSS) serrated polyps. RNF43 hot-spot mutations were discovered in seven serrated polyps and 12 conventional adenomas from Lynch patients. CONCLUSION: Truncating germline RNF43 mutations are uncommon in SPS patients. Somatic mutations in RNF43 were found in sporadic TSA and SSL and both serrated polyps and adenomas from Lynch syndrome patients, suggesting that they do not develop early in the pathway to CRC and are not specific for serrated polyp subtypes.

Is a colorectal neoplasm diagnosis a trigger to change dietary and other lifestyle habits for persons with Lynch syndrome? A prospective cohort study.

A cancer diagnosis is suggested to be associated with changes in dietary and lifestyle habits. Whether this applies to persons with familial cancer, such as Lynch syndrome (LS) is unknown. We investigated whether a colorectal neoplasm (CRN) diagnosis in persons with LS is associated with changes in dietary and lifestyle habits over time. We used data of confirmed LS mutation carriers from the GEOLynch study, a prospective cohort study. Information on dietary intake and lifestyle habits was collected with a validated semi-quantitative food frequency questionnaire and a general questionnaire administered at baseline (2006-2008) and follow-up (2012-2017). Participants' medical records were used to identify CRN diagnoses. Changes in dietary and lifestyle habits in the CRN and the no-CRN group were compared using multivariable linear regression models for continuous variables and cross-tables with percentage change at follow-up compared with baseline for categorical variables. Of the 324 included participants, 146 developed a CRN (CRN group) between baseline and follow-up, while 178 did not (no-CRN group). Smoking cessation was more often reported in the CRN than in the no-CRN group (41.4% vs. 35.0%). There were no differences in changes of energy intake, alcohol, red meat, processed meat, dairy, fruit, vegetables and dietary fiber consumption, BMI, physical activity and NSAID use. Apart from a potentially higher likelihood of smoking cessation, we found little evidence that a CRN diagnosis is associated with changes in lifestyle habits in persons with LS.