Magnetic Resonance Enterography and Histology in Patients With Fibrostenotic Crohn's Disease: A Multicenter Study

INTRODUCTION

Magnetic resonance enterography (MRE) is useful for detecting bowel strictures, whereas a number of imaging biomarkers may reflect severity of fibrosis burden in Crohn's disease (CD). This study aimed to verify the association of MRE metrics with histologic fibrosis independent of inflammation.

METHODS

This prospective European multicenter study performed MRE imaging on 60 patients with CD with bowel strictures before surgical resection. Locations of 61 histological samples were annotated on MRE examinations, followed by central readings using the Chiorean score and measurement of delayed gain of enhancement (DGE), magnetization transfer ratio, T2-weighted MRI sequences (T2R), apparent diffusion coefficient (ADC), and the magnetic resonance index of activity (MaRIA). Correlations of histology and MRE metrics were assessed. Least Absolute Shrinkage and Selection Operator and receiver operator characteristic (ROC) curve analyses were used to select composite MRE scores predictive of histology and to estimate their predictive value.

RESULTS

ADC and MaRIA correlated with fibrosis (R = -0.71, P < 0.0001, and 0.59, P < 0.001) and more moderately with inflammation (R = -0.35, P < 0.01, and R = 0.53, P < 0.001). Lower or no correlations of fibrosis or inflammation were found with DGE, magnetization transfer ratio, or T2R. Least Absolute Shrinkage and Selection Operator and ROC identified a composite score of MaRIA, ADC, and DGE as a very good predictor of histologic fibrosis (ROC area under the curve = 0.910). MaRIA alone was the best predictor of histologic inflammation with excellent performance in identifying active histologic inflammation (ROC area under the curve = 0.966).

DISCUSSION

MRE-based scores for histologic fibrosis and inflammation may assist in the characterization of CD stenosis and enable development of fibrosis-targeted therapies and clinical treatment of stenotic patients.

Epigenome-Wide DNA Methylation Profiling of Normal Mucosa Reveals HLA-F Hypermethylation as a Biomarker Candidate for Serrated Polyposis Syndrome

Serrated polyposis syndrome (SPS) is associated with a high risk for colorectal cancer. Intense promoter hypermethylation is a frequent molecular finding in the serrated pathway and may be present in normal mucosa, predisposing to the formation of serrated lesions. To identify novel biomarkers for SPS, fresh-frozen samples of normal mucosa from 50 patients with SPS and 19 healthy individuals were analyzed by using the 850K BeadChip Technology (Infinium). Aberrant methylation levels were correlated with gene expression using a next-generation transcriptome profiling tool. Two validation steps were performed on independent cohorts: first, on formalin-fixed, paraffin-embedded tissue of the normal mucosa; and second, on 24 serrated lesions. The most frequently hypermethylated genes were HLA-F, SLFN12, HLA-DMA, and RARRES3; and the most frequently hypomethylated genes were PIWIL1 and ANK3 (Δβ = 10%; P < 0.05). Expression levels of HLA-F, SLFN12, and HLA-DMA were significantly different between SPS patients and healthy individuals and correlated well with the methylation status of the corresponding differentially methylated region (fold change, >20%; r > 0.55; P < 0.001). Significant hypermethylation of CpGs in the gene body of HLA-F was also found in serrated lesions (Δβ = 23%; false discovery rate = 0.01). Epigenome-wide methylation profiling has revealed numerous differentially methylated CpGs in normal mucosa from SPS patients. Significant hypermethylation of HLA-F is a novel biomarker candidate for SPS.

An Immune-metabolic signature (IMMETCOLS) identifies three clusters in mCRC with different immune-phenotype distribution and potential clinical implications

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Background: The overall response rate following immune check-point blockade (ICB) is < 5% in microsatellite stable (MSS) advanced colorectal cancer (mCRC), and between 30-35% in MSI mCRC. We here evaluate the relationship between our immune-metabolic signature (IMMETCOLS) distribution (cluster (IMC) 1; mesenchymal glycolytic, IMC 2; epithelial-non glycolytic and IMC 3; epithelial mitochondrial oxidative) with immune phenotypes (inflamed (IF), immune-excluded (IE) and immune-desert (ID)) in MSS and MSI mCRC patients (pts). Methods: We have analyzed IMMETCOLS in a retrospective cohort of 128 mCRC pts enriched with MSI-H and BRAF genotype using the nCounter platform (Nanostring Technologies, US). Immune phenotypes were evaluated by immunohistochemistry using 7 immune markers (CD68, CD163, CD8, CD3, FOXP3, PD-L1 and PD1) in a subset of 47 mCRC pts (27 MSS and 20 MSI), in TMAs containing 4 cores from the center of the tumor (CT) and invasive front (IF). The number of stained immune cells was counted using a computerized image analysis system, and PD-L1 was evaluated using CPS score (< 1 vs > 1). Patients having a CD3 cell count below 572 cells/mm2 and a CD8 density below 175 cells/mm2 in IF or CT were considered as ID. (Halama Nils, 2011). CD3 density was also semi-quantitatively estimated in peritumoral stroma and intra-tumoral (range 1-4), defining as IE those cases with a difference > 1 between the two regions in both IF and CT (Brooks JM, 2019). Results: Cluster distribution was similar between MSI (IMC1-40%, IMC2-20% and IMC-40%) and MSS (IMC1-34%, IMC2-24%, IMC3-43%) pts. Patients with high LDH levels (> 1.5ULN) were enriched with IMC3 phenotype (p < 0.0001). MSI have increased CD3 (p = 0.002), CD68 (p = 0.002) and CD163 (p = 0.001) in CT than MSS patients. IMC1 pts had increased CD163/CD68 ratio in CT (p = 0.004). 75% of MSI pts were IE and 25% IF. 55% of MSS pts were IE, 38% ID and 7% IF. IMMETCOLS/ immune-phenotype distribution was: IMC1 (16% ID/ 84% IE), IMC2 (12% ID/ 63% IE/ 25% IF) and IMC3 (35%ID/ 47% IE/ 18% IF). PD1 immuno-expression > 1% (IF and CT) and PD-L1 positivity was observed in 38%, 30% and 28% of pts respectively. There were no differences in PD-L1 (CPS) and PD1 expression between MSS and MSI tumors. Inflamed tumors show higher PD-L1 expression compared with IE and ID immune-phenotypes (p = 0.014). PD1 > 1% expression at IF was significatively lower in IMC1 vs IMC2 and IMC3 tumors (p = 0.032). Conclusions: IMC1 subtype is associated with low PD1 expression, high CD163/CD68 ratio and IE phenotype even in MSI-H mCRC patients. Therefore, IMMETCOLS testing would be of value to identify MSI mCRC pts that do not benefit to ICB therapy.

Patient Experience in Pancreas-Kidney Transplantation-A Methodological Approach Towards Innovation in an Established Program

Simultaneous pancreas-kidney transplantation (SPKT) leads to increased survival and quality of life, and is an alternative treatment for insulin-dependent diabetes mellitus and end-stage kidney disease. Due to the particularities of this population (often with multiple comorbidities) and of the surgery (only performed in a few centers), a comprehensive analysis of patients' experience along the SPKT process is crucial to improve patient care and add value to this procedure. Therefore, we applied a systematic and iterative methodology with the participation of both patients and professional teams working together to explore and identify unmet needs and value-adding steps along the transplant patient journey at an established pancreas transplant program. Four main steps (to comprehend, to explore, to experiment and to assess) led to several interventions around three major areas: Administration and logistics, information and communication, and perceived quality of assistance. As a result, both displacements to the hospital for diagnostic purposes and the time delay involved in joining the patient waiting list for transplantation were reduced in parallel to the administrative procedures. In conclusion, the methodological implementation of key organizational changes has great impact on overall patient experience. Further quantitative analysis from the patient's perspective will consolidate our program and may add new prototype service design components.

Copy-number intratumor heterogeneity increases the risk of relapse in chemotherapy-naive stage II colon cancer

Optimal selection of high-risk patients with stage II colon cancer is crucial to ensure clinical benefit of adjuvant chemotherapy. Here, we investigated the prognostic value of genomic intratumor heterogeneity and aneuploidy for disease recurrence. We combined targeted sequencing, SNP arrays, fluorescence in situ hybridization, and immunohistochemistry on a retrospective cohort of 84 untreated stage II colon cancer patients. We assessed the clonality of copy-number alterations (CNAs) and mutations, CD8⁺ lymphocyte infiltration, and their association with time to recurrence. Prognostic factors were included in machine learning analysis to evaluate their ability to predict individual relapse risk. Tumors from recurrent patients displayed a greater proportion of CNAs compared with non-recurrent (mean 31.3% versus 23%, respectively; p = 0.014). Furthermore, patients with elevated tumor CNA load exhibited a higher risk of recurrence compared with those with low levels [p = 0.038; hazard ratio (HR) 2.46], which was confirmed in an independent cohort (p = 0.004; HR 3.82). Candidate chromosome-specific aberrations frequently observed in recurrent cases included gain of the chromosome arm 13q (p = 0.02; HR 2.67) and loss of heterozygosity at 17q22-q24.3 (p = 0.05; HR 2.69). CNA load positively correlated with intratumor heterogeneity (R = 0.52; p < 0.0001). Consistently, incremental subclonal CNAs were associated with an elevated risk of relapse (p = 0.028; HR 2.20), which we did not observe for subclonal single-nucleotide variants and small insertions and deletions. The clinico-genomic model rated an area under the curve of 0.83, achieving a 10% incremental gain compared with clinicopathological markers (p = 0.047). In conclusion, tumor aneuploidy and copy-number intratumor heterogeneity were predictive of poor outcome and improved discriminative performance in early-stage colon cancer. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Impact of microscopic incomplete resection for colorectal liver metastases on surgical margin recurrence: R1-Contact vs R1 < 1 mm margin width

BACKGROUND

Several studies highlighted an inferior outcome of R1 resection for colorectal cancer liver metastases (CRLM); it is still unclear whether directly involved margins (R1-contact) are associated with a poorer outcome compared to R1 < 1 mm. The aim of this study is to analyze the impact on surgical margin recurrence (SMR) of R1-contact vs R1 < 1 mm patients.

METHODS

Patients who underwent surgery for CRLM between 2009-2018 with both R1 resections on final histology were included and compared in terms of recurrence and survival. Factors associated with SMR were assessed by univariate and multivariate analysis.

RESULTS

Out of 477, 77 (17.2%) patients showed R1 resection (53 R1-Contact and 24 R1 < 1 mm). Overall recurrence rate was 79.2% (R1 < 1 mm = 70.8% vs R1-contact group = 83%, P = .222). Median disease-free survival (DFS) and disease-specific survival (DSS) were significantly higher in R1 < 1 mm vs R1-contact group (93 vs 55 months; P = .025 and 69 vs 46 months; P = .038, respectively). The SMR rate was higher in R1-contact compared to R1 < 1 mm group (30.2% vs 8.3%; P = .036). At univariate analysis, age, number of metastases, open surgical approach, RAS status, and R1-contact were associated with SMR. At multivariate analysis, R1-contact margin was the only factor independently associated with higher SMR (OR = 5.6; P = .046).

CONCLUSIONS

R1-contact margin is independently associated with SMR after liver resection for CRLM. Patients with R1-contact margin will also experience poorer DFS and DSS.

Identification of Lynch Syndrome Carriers among Patients with Small Bowel Adenocarcinoma

Simple Summary

Small bowel adenocarcinoma (SBA) is associated with Lynch syndrome (LS). This is the first study to evaluate the identification of LS patients based on mismatch repair deficiency (MMRd) tumor among SBA. The authors found a 21.3% prevalence of MMRd tumors and a 10.1% prevalence of LS. A germline mutation was identified in 60% of patients with a MMRd tumor. This data suggests that universal tumor MMR testing among SBA patients should be implemented for the identification of LS.

Abstract

Background: Small bowel adenocarcinoma (SBA) is a rare disease which can be associated with Lynch syndrome (LS). LS tumors are characterized by the presence of microsatellite instability (MSI) and/or the loss of mismatch repair (MMR) protein expression. In SBA, the frequency of MMR deficient (MMRd) tumors varies from 5% to 35%. This study aims to describe the prevalence of LS carriers among patients with MMRd small bowel adenocarcinomas. Methods: A multicenter retrospective study with identification and MMR testing of all consecutive SBA between 2004 and 2020 in a multicenter Spanish study. Demographical data, tumor characteristics, follow-up and survival information were collected. Germline testing was driven by identification of MMRd tumors. Results: A total of 94 individuals diagnosed with SBA were recruited. We observed 20 (21.3%) MMRd tumors. In 9/15 (60%) patients with MMRd tumors, a pathogenic variant was identified (three MLH1, four MSH2, one MSH6 and one PMS2). Accordingly, the prevalence of LS among all SBA cases was 10.1%. Conclusions: More than one-fifth of SBA display MMRd and in more than a half is due to LS. Our data supports the implementation of universal MMR tumor testing among SBA for the identification of LS families.

KRAS phosphorylation regulates cell polarization and tumorigenic properties in colorectal cancer

Oncogenic mutations of KRAS are found in the most aggressive human tumors, including colorectal cancer. It has been suggested that oncogenic KRAS phosphorylation at Ser181 modulates its activity and favors cell transformation. Using nonphosphorylatable (S181A), phosphomimetic (S181D), and phospho-/dephosphorylatable (S181) oncogenic KRAS mutants, we analyzed the role of this phosphorylation to the maintenance of tumorigenic properties of colorectal cancer cells. Our data show that the presence of phospho-/dephosphorylatable oncogenic KRAS is required for preserving the epithelial organization of colorectal cancer cells in 3D cultures, and for supporting subcutaneous tumor growth in mice. Interestingly, gene expression differed according to the phosphorylation status of KRAS. In DLD-1 cells, CTNNA1 was only expressed in phospho-/dephosphorylatable oncogenic KRAS-expressing cells, correlating with cell polarization. Moreover, lack of oncogenic KRAS phosphorylation leads to changes in expression of genes related to cell invasion, such as SERPINE1, PRSS1,2,3, and NEO1, and expression of phosphomimetic oncogenic KRAS resulted in diminished expression of genes involved in enterocyte differentiation, such as HNF4G. Finally, the analysis, in a public data set of human colorectal cancer, of the gene expression signatures associated with phosphomimetic and nonphosphorylatable oncogenic KRAS suggests that this post-translational modification regulates tumor progression in patients.

Ex vivo Fusion Confocal Microscopy of Colorectal Polyps: A Fast Turnaround Time of Pathological Diagnosis

BACKGROUND

Colorectal cancer screening programs have accomplished a mortality reduction from the disease but have created bottlenecks in endoscopy units and pathology departments. We aimed to explore the feasibility of ex vivo fusion confocal microscopy (FuCM) to improve the histopathology diagnostic efficiency and reduce laboratory workload.

METHODS

Consecutive fresh polyps removed at colonoscopy were scanned using ex vivo FuCM, then went through histopathologic workout and hematoxylin and eosin (H&amp;E) diagnosis. Two pathologists blinded to H&amp;E diagnosis made a diagnosis based on FuCM scanned images.

RESULTS

Thirty-six fresh polyps from 22 patients were diagnosed with FuCM and H&amp;E. Diagnostic agreement between H&amp;E and FuCM was 97.2% (kappa = 0.96) for pathologist #1 and 91.7% (kappa = 0.87) for pathologist #2. Diagnostic performance concordance between FuCM and H&amp;E to discern adenomatous from nonadenomatous polyps was 100% (kappa = 1) for pathologist #1 and 97.2% (kappa = 0.94) for pathologist #2. Global interobserver agreement was 94.44% (kappa = 0.91) and kappa = 0.94 to distinguish adenomatous from nonadenomatous polyps.

CONCLUSIONS

Ex vivo FuCM shows an excellent correlation with standard H&amp;E for the diagnosis of colorectal polyps. The clinical direct benefit for patients, pathologists, and endoscopists allows adapting personalized surveillance protocols after colonoscopy and a workload decrease in pathology departments.

Diagnosis of Helicobacter pylori Infection by the Arrangement of Collecting Venules Using White Light Endoscopy: Evaluation of Interobserver Agreement

BACKGROUND

Regular arrangement of collecting venules (RAC) in gastric mucosa accurately identifies patients without Helicobacter pylori (H pylori) infection. The aim of our study was to evaluate the reproducibility of RAC using white light endoscopy without magnification, in a European country, and to assess the impact of proton pump inhibitors (PPIs).

METHODS

A multicenter prospective study with image capture of the distal lesser gastric curvature and gastric biopsies was performed. The presence of starfish-like minute points regularly distributed throughout lesser curvature was considered as RAC positive (RAC+). A set of 20 images was used for the training phase and inter and intra-observer agreements were calculated.

RESULTS

174 patients were included and 85 (48.9%) were taking PPIs. Kappa values for interobserver and intra-observer agreements were substantial (0.786) and excellent (0.906), respectively. H. pylori infection was diagnosed in 29 patients (16.7%): 10/85 with PPIs and 19/89 without PPIs (11.8% vs. 21.3%; p = 0.09). All RAC + patients were free of H. pylori infection, with a sensitivity and negative predictive value of 100%, regardless of PPI intake.

CONCLUSION

The endoscopic diagnosis of H. pylori by RAC is an easy-to-learn and highly reproducible technique, even with PPI intake. Our results warrant RAC as a real-time diagnostic method for H. pylori-negative infection in Western practice.

Clinical, Molecular and Genetic Characteristics of Early Onset Gastric Cancer: Analysis of a Large Multicenter Study

Gastric adenocarcinoma (GC) is a common tumor with high morbidity and mortality. Only 7% of patients with GC are diagnosed before age 50 (early onset gastric cancer (EOGC)), and their characteristics have been poorly described. We aimed to describe clinical, molecular, and genetic characteristics of EOGC. A total of 309 patients with EOGC were retrospectively studied in four Spanish centers. Personal information, family history, and tumor information were registered. Germinal genetic analysis was performed in patients who met current criteria of a hereditary syndrome at the time of diagnosis. The median age at diagnosis was 44 years. The majority (73.3%) of tumors were diffuse, and 78.3% were diagnosed in an advanced stage. Familial aggregation of GC was present in 18/117 (15.4%) cases, and 5/117 (4.3%) met criteria for familial GC. MMR-IHC was performed in 126/309 (40.7%) tumors: 4/126 (3.1%) had loss of expression in MLH1/PMS2, without an associated germline mutation. Sixteen germline genetic analyses were performed, detecting a pathogenic variant in four (25%) cases: one in BRCA2, one in TP53, and two in CDH1. Most EOGC are diffuse and diagnosed in an advanced stage. In these patients, DNA MMR system deficiency is uncommon. Although familial aggregation was observed in only 15% of cases, a germline mutation was found in 25% of patients tested with clinical criteria. This demonstrates that EOGC has a marked genetic heterogeneity, reinforcing the importance of an accurate genetic counseling and enhancing the emerging use of multigene panels.

Zeb1 induces immune checkpoints to form an immunosuppressive envelope around invading cancer cells

The PDL1-PD1 immune checkpoint inhibits T cell activation, and its blockade is effective in a subset of patients. Studies are investigating how checkpoints are hijacked by cancer cells and why most patients remain resistant to immunotherapy. Epithelial mesenchymal transition (EMT), which drives tumor cell invasion via the Zeb1 transcription factor, is linked to immunotherapy resistance. In addition, M2-polarized tumor-associated macrophages (TAMs), which inhibit T cell migration and activation, may also cause immunotherapy resistance. How EMT in invading cancer cells is linked to therapy resistance and events driving TAM M2 polarization are therefore important questions. We show that Zeb1 links these two resistance pathways because it is required for PDL1 expression on invading lung cancer cells, and it also induces CD47 on these invading cells, which drives M2 polarization of adjacent TAMs. Resulting reprogramming of the microenvironment around invading cells shields them from the hostile inflammatory environment surrounding tumors.

Description of the genetic variants identified in a cohort of patients diagnosed with localized anal squamous cell carcinoma and treated with panitumumab

Squamous cell carcinoma is the most frequent histologic type of anal carcinoma. The standard of care since the 1970s has been a combination of 5-fluorouracil, mitomycin C, and radiotherapy. This treatment is very effective in T1/T2 tumors (achieving complete regression in 80–90% of tumors). However, in T3/T4 tumors, the 3-year relapse free survival rate is only 50%. The VITAL trial aimed to assess the efficacy and safety of panitumumab in combination with this standard treatment. In this study, 27 paraffin-embedded samples from the VITAL trial and 18 samples from patients from daily clinical practice were analyzed by whole-exome sequencing and the influence of the presence of genetic variants in the response to panitumumab was studied. Having a moderate- or high-impact genetic variant in PIK3CA seemed to be related to the response to panitumumab. Furthermore, copy number variants in FGFR3, GRB2 and JAK1 were also related to the response to panitumumab. These genetic alterations have also been studied in the cohort of patients from daily clinical practice (not treated with panitumumab) and they did not have a predictive value. Therefore, in this study, a collection of genetic alterations related to the response with panitumumab was described. These results could be useful for patient stratification in new anti-EGFR clinical trials.

Improving tumor budding reporting in colorectal cancer: a Delphi consensus study

Tumor budding is a long-established independent adverse prognostic marker in colorectal cancer, yet methods for its assessment have varied widely. In an effort to standardize its reporting, a group of experts met in Bern, Switzerland, in 2016 to reach consensus on a single, international, evidence-based method for tumor budding assessment and reporting (International Tumor Budding Consensus Conference [ITBCC]). Tumor budding assessment using the ITBCC criteria has been validated in large cohorts of cancer patients and incorporated into several international colorectal cancer pathology and clinical guidelines. With the wider reporting of tumor budding, new issues have emerged that require further clarification. To better inform researchers and health-care professionals on these issues, an international group of experts in gastrointestinal pathology participated in a modified Delphi process to generate consensus and highlight areas requiring further research. This effort serves to re-affirm the importance of tumor budding in colorectal cancer and support its continued use in routine clinical practice.

Lymph Node Tumor Burden Correlates With Tumor Budding and Poorly Differentiated Clusters: A New Prognostic Factor in Colorectal Carcinoma?

INTRODUCTION

Molecular lymph node (LN) staging in early colorectal cancer (CRC) has demonstrated to be more precise than conventional histopathology pN staging. Tumor budding (TB) and poorly differentiated clusters (PDCs) are associated with LN metastases, recurrences, and lower survival in CRC. We evaluated the correlation between the total tumor load (TTL) in LNs from CRC surgical specimens with patient outcome, TB, and PDC.

METHODS

In this retrospective multicentre study, 5,931 LNs from 342 stage I-III CRC were analyzed by both hematoxylin and eosin and molecular detection of tumor cytokeratin 19 mRNA by one-step nucleic acid amplification. TB and PDC were evaluated by hematoxylin and eosin and cytokeratin 19 immunohistochemistry.

RESULTS

One-step nucleic acid was positive in 38.3% patients (n = 131). Tumor Budding was low in 45% cases, intermediate in 25%, and high in 30%. Poorly Differentiated Clusters were low-grade G1 in 53%, G2 in 32%, and G3 in 15%. TB and PDC correlated with TTL, high-grade, lymphovascular and perineural invasion, pT, pN and stage (P < 0.001). TB, PDC, and TTL ≥ 6,000 copies/µL were associated with worse overall survival (P = 0.002, P = 0.013, and P = 0.046) and disease-free survival (P < 0.001).

DISCUSSION

The implementation of more sensitive molecular methods to assess LN status is a promising alternative approach to pN staging, which could be integrated to other factors to help risk stratification and management of patients with early-stage CRC. This study demonstrates the correlation of the amount of LN tumor burden with TB and PDCs. TTL is related to the outcome and could be used as a new prognostic factor in CRC (see Visual Abstract, Supplementary Digital Content 2, http://links.lww.com/CTG/A512).

Germline and Somatic Whole-Exome Sequencing Identifies New Candidate Genes Involved in Familial Predisposition to Serrated Polyposis Syndrome

The serrated polyposis syndrome (SPS) is the most common and yet underdiagnosed colorectal polyposis syndrome. It is characterized by multiple and/or large colonic serrated polyps and a higher associated risk for colorectal cancer (CRC). The main objective of this study was to identify new candidate genes involved in the germline predisposition to SPS/CRC. Thirty-nine SPS patients from 16 families (≥2 patients per family) were recruited without alterations in well-known hereditary CRC genes, and germline and somatic whole-exome sequencing were performed. Germline rare variants with plausible pathogenicity, located in genes involved in cancer development, senescence and epigenetic regulation were selected. Somatic mutational profiling and signature analysis was pursued in one sample per family, when possible. After data filtering, ANXA10, ASXL1, CFTR, DOT1L, HIC1, INO80, KLF3, MCM3AP, MCM8, PDLIM2, POLD1, TP53BP1, WNK2 and WRN were highlighted as the more promising candidate genes for SPS germline predisposition with potentially pathogenic variants shared within families. Somatic analysis characterized mutational profiles in advanced serrated polyps/tumors, revealing a high proportion of hypermutated samples, with a prevalence of clock-like mutational signatures in most samples and the presence of DNA mismatch repair-defective signatures in some cases. In conclusion, we identified new candidate genes to be involved in familial SPS. Further functional studies and replication in additional cohorts are required to confirm the selected candidates.

Quality in diagnostic upper gastrointestinal endoscopy for the detection and surveillance of gastric cancer precursor lesions: Position paper of AEG, SEED and SEAP

This position paper, sponsored by the Asociación Española de Gastroenterología [Spanish Association of Gastroenterology], the Sociedad Española de Endoscopia Digestiva [Spanish Gastrointestinal Endoscopy Society] and the Sociedad Española de Anatomía Patológica [Spanish Anatomical Pathology Society], aims to establish recommendations for performing an high quality upper gastrointestinal endoscopy for the screening of gastric cancer precursor lesions (GCPL) in low-incidence populations, such as the Spanish population. To establish the quality of the evidence and the levels of recommendation, we used the methodology based on the GRADE system (Grading of Recommendations Assessment, Development and Evaluation). We obtained a consensus among experts using a Delphi method. The document evaluates different measures to improve the quality of upper gastrointestinal endoscopy in this setting and makes recommendations on how to evaluate and treat the identified lesions. We recommend that upper gastrointestinal endoscopy for surveillance of GCPL should be performed by endoscopists with adequate training, administering oral premedication and use of sedation. To improve the identification of GCPL, we recommend the use of high definition endoscopes and conventional or digital chromoendoscopy and, for biopsies, NBI should be used to target the most suspicious areas of intestinal metaplasia. Regarding the evaluation of visible lesions, the risk of submucosal invasion should be evaluated with magnifying endoscopes and endoscopic ultrasound should be reserved for those with suspected deep invasion. In lesions amenable to endoscopic resection, submucosal endoscopic dissection is considered the technique of choice.

Clinical impact of preoperative tumour contact with superior mesenteric-portal vein in patients with resectable pancreatic head cancer

INTRODUCTION

The NCCN classification of resectability in pancreatic head cancer does not consider preoperative radiological tumour ≤ 180° contact with portal vein/superior mesenteric vein (PV/SMV) as a negative prognostic feature. The aim of this study is to evaluate whether this factor is associated with higher rate of incomplete resection and poorer survival.

METHODS

All patients considered for pancreatic resection between 2012 and 2017 at two Spanish referral centres were included. Patients with borderline and locally advanced pancreatic ductal adenocarcinoma (PDAC) according to NCCN classification were excluded. Preoperative CT scans were reviewed by dedicated radiologists to identify radiologic tumour contact with PV/SMV.

RESULTS

Out of 302, 71 patients were finally included in this study. Twenty-two (31%) patients showed tumour-PV/SMV contact (group 1) and 49 (69%) did not show any contact (group 2). Patients in group 1 showed a statistically significantly higher rate of R1 and R1-direct margins compared with group 2 (95 vs 28% and 77 vs 10%) and lower median survival (24 vs 41 months, p = 0.02). Preoperative contact with PV/SMV, lymph node metastases, R1-direct margin and NO adjuvant chemotherapy were significantly associated with disease-specific survival at multivariate analysis.

CONCLUSION

Preoperative radiological tumour contact with PV/SMV in patients with NCCN resectable PDAC is associated with high rate of pathologic positive margins following surgery and poorer survival.

Early intestinal complications following pancreas transplantation: lessons learned from over 300 cases - a retrospective single-center study

Enteric complications remain a major cause of morbidity in the post-transplant period of pancreas transplantation despite improvements surgical technique. The aim of this single-center study was to analyze retrospectively the early intestinal complications and their potential relation with vascular events. From 2000 to 2016, 337 pancreas transplants were performed with systemic venous drainage. For exocrine secretion, intestinal drainage was done with hand-sewn anastomosis duodenojejunostomy. Twenty-three patients (6.8%) had early intestinal complications. Median age was 39 years (male: 65.2%). Median cold ischemia time was 11 h [IQR: 9-12.4]. Intestinal complications were intestinal obstruction (n = 7); paralytic ileus (n = 5); intestinal fistula without anastomotic dehiscence (n = 3); ischemic graft duodenum (n = 3); dehiscence of duodenojejunostomy (n = 4); and anastomotic dehiscence in jejunum after pancreas transplantectomy (n = 1). Eighteen cases required relaparotomy: adhesiolysis (n = 6); repeated laparotomy without findings (n = 1); transplantectomy (n = 6); primary leak closure (n = 3); re-positioning of the graft (n = 1); and intestinal resection (n = 1). Of the intestinal complications, 4 were associated with vascular thrombosis, resulting in two pancreatic graft losses. Enteric drainage with duodenum-jejunum anastomosis is safe and feasible, with a low rate of intra-abdominal complications. Vascular thrombosis associated with intestinal complications presents a risk factor for the viability of pancreatic grafts, so prevention and early detection is vital.

[Update of the recommendations for the determination of biomarkers in colorectal carcinoma. National Consensus of the Spanish Society of Medical Oncology and the Spanish Society of Pathology]

This update of the consensus of the Spanish Society of Medical Oncology (Sociedad Española de Oncología Médica - SEOM) and the Spanish Society of Pathology (Sociedad Española de Anatomía Patológica - SEAP), reviews the advances in the analysis of biomarkers in advanced colorectal cancer (CRC) as well as susceptibility markers of hereditary CRC and molecular biomarkers of localized CRC. Recently published information on the essential determination of KRAS, NRAS and BRAF mutations and the possible benefits of determining the amplification of human epidermal growth factor receptor 2 (HER2), the expression of proteins in the DNA repair pathway and the study of NTRK fusions are also evaluated. From a pathological point of view, the importance of analysing the tumour budding and poorly differentiated clusters and its prognostic value in CRC is reviewed, as well as the impact of molecular lymph node analysis on lymph node staging in CRC. The incorporation of pan-genomic technologies, such as next-generation sequencing (NGS) and liquid biopsy in the clinical management of patients with CRC is also outlined. All these aspects are developed in this guide which, like the previous one, will be revised when necessary in the future.

Germline biallelic Mcm8 variants are associated with early-onset Lynch-like syndrome

Lynch syndrome is the most common cause of hereditary colorectal cancer (CRC), and it is characterized by DNA mismatch repair (MMR) deficiency. The term Lynch-like syndrome (LLS) is used for patients with MMR-deficient tumors and neither germline mutation in MLH1, MSH2, MSH6, PMS2, or EPCAM nor MLH1 somatic methylation. Biallelic somatic inactivation or cryptic germline MMR variants undetected during genetic testing have been proposed to be involved. Sixteen patients with early-onset LLS CRC were selected for germline and tumor whole-exome sequencing. Two potentially pathogenic germline MCM8 variants were detected in a male patient with LLS with fertility problems. A knockout cellular model for MCM8 was generated by CRISPR/Cas9 and detected genetic variants were produced by mutagenesis. DNA damage, microsatellite instability, and mutational signatures were monitored. DNA damage was evident for MCM8^KO cells and the analyzed genetic variants. Microsatellite instability and mutational signatures in MCM8^KO cells were compatible with the involvement of MCM8 in MMR. Replication in an independent familial cancer cohort detected additional carriers. Unexplained MMR-deficient CRC cases, even showing somatic biallelic MMR inactivation, may be caused by underlying germline defects in genes different than MMR genes. We suggest MCM8 as a gene involved in CRC germline predisposition with a recessive pattern of inheritance.

MCM8 may be involved in germline predisposition to colorectal cancer in Lynch-like syndrome cases.