Pathology of premalignant colorectal neoplasia

p53 protein degradation redefines the initiation mechanisms and drives transitional mutations in colorectal cancer

Incidence of colorectal cancer (CRC) is increasing likely due to different mechanisms driving initiation and progression. The initial model proposed by Fearon and Vogelstein posits it as a multi-hit neoplasia, originating from adenomatous-polyps induced by WNT activation, ultimately progressing to aggressiveness through p53 loss. Integrating human data with mouse genetics, we redefine this paradigm, highlighting pivotal roles of MYC, oncogenic URI and p53 degradation to initiate CRC. Early APC loss activates MYC to transcriptionally upregulate URI, which modulates MDM2 activity, triggering p53 proteasomal degradation, essential for tumour initiation and mutation burden accrual in CRC mice. Remarkably, reinstating p53 levels via genetic URI depletion or p53 super-expression in CRC mice with WNT pathway activation prevents tumour initiation and extends lifespan. Our data reveal a "two-hit" genetic model central to APC loss-driven CRC initiation, wherein MYC/URI axis intricately controls p53 degradation, offering mechanistic insights into transitional mutation acquisition essential for CRC progression.

Mismatch Repair Proficient Colorectal Adenocarcinoma in Two Patients With Lynch Syndrome

Screening for Lynch syndrome (LS) is essential in colorectal carcinoma (CRC) diagnosis. The hallmark of CRC in LS is mismatch repair (MMR) deficiency, a vital biomarkers assessed by microsatellite instability (MSI) analysis and/or immunohistochemistry (IHC) staining of the MMR proteins in the tumor, that also predict response to immune checkpoint inhibitors. We report two LS patients who developed MMR proficient CRCs. Patient A, with a pathogenic MSH6 germline variant, presented with two MMR discordant CRCs: a rectal MMRd/MSI adenocarcinoma, and a sigmoid MMR proficient (MMRp) and microsatellite stable (MSS) adenocarcinoma, leading to metastasis. While the MMRd/MSI carcinoma was recognized early and showed complete pathologic response after pembrolizumab treatment, the MMRp/MSS adenocarcinoma was underrecognized and poorly responsive to treatment. A second patient, with a pathogenic PMS2 variant, also developed a MMRp CRC. These cases highlight the complex biological pathways in CRC development and the impact of molecular classification on treatment.

A National Cancer Database Analysis of the Characteristics and Outcome of Colon Cancer According to Type of Preexisting Adenoma

BACKGROUND

The vast majority of colon cancers occur in pre-existing adenomas. Little is known about the impact of adenoma type on behavior and outcome of subsequent carcinomas. The present study aimed to assess characteristics, behavior, and outcome of colon adenocarcinoma based on histologic type of pre-existing adenoma.

METHODS

US-National Cancer Database was searched between 2005 and 2019 for patients with colonic adenocarcinoma with known adenoma type who underwent colectomy. Patients were divided into 3 groups according to type of adenoma in which carcinoma developed: tubular adenoma (TA), villous adenoma (VA), and tubulovillous adenoma (TVA)-associated carcinomas. The main outcome of the study was 5-year overall survival (OS).

RESULTS

66,854 patients were included. 79.3% of carcinomas originated from TVA, 10.2% from VA, and 0.5% from TA. Patients with adenocarcinoma in VA were more often female whereas carcinomas in TA affected patients of Asian race more often. Approximately one-third of carcinomas in villous and tubulovillous adenomas were in the cecum whereas one-third of carcinomas in tubular adenomas were in the sigmoid colon. More TA-associated carcinomas were of clinical T1-2 stage (30.2% vs. 20.8%; P < .001), clinical N0 stage (69% vs. 62.2%, P < .001), and high grade (15.9% vs. 11.5%, P < .001) compared to VA-associated carcinomas. Patients with TA-associated carcinomas had longer mean OS than patients with VA and TVA-associated carcinomas (130.1 vs. 116.9 vs. 123.5 months, P < .0001).

CONCLUSIONS

Adenocarcinomas that arose in TA had more T1-2 stage and N0 stage, higher grade, and longer OS than did adenocarcinomas that arose in VA and TVA.

Dysplastic crypts with lateral buddings in tubular adenomas

Tubular adenomas (TA) are the most frequent of all colorectal adenomas. Current definitions of TA do not include the phenotype of the dysplastic crypts. We report a novel crypt phenotype characterized by dysplastic crypts with lateral buddings (DCLB). Out of the 309 TA, 25.9 % (n=80) exhibited DCLBs: 12.5 % (n=10) had one DCLB focus/TA, 15.0 % (n=12) had two DCLB foci/TA, 27.5 % (n=22) three had three DCLB foci/TA, 30.0 % (n=24) had four DCLB foci/TA, 12.5 % (n=10) had five DCLB foci/TA, and in the remaining 2.5 %n (n=2) most fields of view at x4 showed DCLB foci. DCLB in TA were generated independently of TA size or degree of dysplasia. The presence of DCLB was not influenced by age, gender or localization. In conclusion, a novel histologic phenotype of TA is showcased. DCLBs are integral components in some of the TA. Recently, another novel dysplastic crypt phenotype in TA characterized by dysplastic crypts in tandem was reported. The awareness that different dysplastic crypt phenotypes thrive in TA might open a new vista on research aimed to learn more about why the most prevalent of all colorectal adenomas thrive with a low capacity to invade the host.

Polyclonal-to-monoclonal transition in colorectal precancerous evolution

Unravelling the origin and evolution of precancerous lesions is crucial for effectively preventing malignant transformation, yet our current knowledge remains limited1-3. Here we used a base editor-enabled DNA barcoding system4 to comprehensively map single-cell phylogenies in mouse models of intestinal tumorigenesis induced by inflammation or loss of the Apc gene. Through quantitative analysis of high-resolution phylogenies including 260,922 single cells from normal, inflamed and neoplastic intestinal tissues, we identified tens of independent cell lineages undergoing parallel clonal expansions within each lesion. We also found polyclonal origins of human sporadic colorectal polyps through bulk whole-exome sequencing and single-gland whole-genome sequencing. Genomic and clinical data support a model of polyclonal-to-monoclonal transition, with monoclonal lesions representing a more advanced stage. Single-cell RNA sequencing revealed extensive intercellular interactions in early polyclonal lesions, but there was significant loss of interactions during monoclonal transition. Therefore, our data suggest that colorectal precancer is often founded by many different lineages and highlight their cooperative interactions in the earliest stages of cancer formation. These findings provide insights into opportunities for earlier intervention in colorectal cancer.

Dysplastic crypt-rings in tandem: A novel histologic parameter in tubular adenomas

Descriptions of the various dysplastic crypt phenotypes occurring in TA have remained unattended in the literature. Recently, new crypt-phenotypes, characterized by crypt rings in tandem (CRT), and by dysplastic crypt rings in tandem (DCRT) were described in IBD, and in in IBD-associated dysplasia, respectively. Here, we report the occurrence of DCRT in 40.4 % (n = 59) out of 146 consecutive tubular adenomas of the colorectum (TA). The number of DCRT varied: 10 TA had two DCRT, seven TA had three DCRT, two TA, four DCRT and the remaining two TA had ≥ five DCRT. The frequency of DCRT was influenced by TA-size; larger TA (≥ 5 mm) had significantly more DCRT than smaller TA (<5 mm). Conversely, the frequency of TA with DCRT was not influenced by age, gender, or localization. Since only 1 or 2 sections were available per TA, the number of DCRT in the entire TA should be higher than those shown in Results. Historical controls in human and rodent normal colorectum showed no CRT. Moreover, DCRT were not found in 781 historical non-polypoid colorectal adenomas. The present finding might encourage searching for DCRT, the final goal being to achieve a more elaborated microscopic narrative of TA, the most prevalent of all colorectal adenomas.

Predictive value of 18F-fluorodeoxyglucose PET/CT in histological grade of incidental colorectal adenoma

BACKGROUND

18F-fluorodeoxyglucose (18F-FDG) positron-emission tomography/computed tomography (PET/CT) as an imaging modality for the whole body has shown its value in detecting incidental colorectal adenoma. In clinical practice, adenomatous polyps can be divided into three groups: low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN) and cancer, which can lead to different clinical management. However, the relationship between the 18F-FDG PET/CT SUVmax and the histological grade of adenomatous polyps is still not established, which is a challenging but valuable task.

METHODS

This retrospective study included 255 patients with colorectal adenoma (CRA) or colorectal adenocarcinomas (AC) who had corresponding 18F-FDG uptake incidentally found on PET/CT. The correlations of SUVmax with pathological characteristics and tumor size were assessed. Neoplasms were divided into LGIN, HGIN, and AC according to histological grade. Receiver operating characteristic (ROC) analysis was applied to evaluate the predictive value of the SUVmax-only model and comprehensive models which were established with imaging and clinical predictors identified by univariate and multivariate analysis.

RESULTS

The SUVmax was positively correlated with histological grades (r=0.529, P<0.001). Univariate and multivariate analysis showed that SUVmax was an independent risk factor among all groups except between HGIN and AC. The area under the curves (AUCs) of the comprehensive model for distinguishing between AC and adenoma, LGIN and HIGN, LGIN and AC, and HGIN and AC were 0.886, 0.780, 0.945, 0.733, respectively, which is statistically higher than the AUCs of the SUVmax-only model with 0.812, 0.733, 0.863, and 0.688, respectively.

CONCLUSIONS

As an independent risk factor, SUVmax based on 18F-FDG PET/CT is highly associated with the histological grade of CRA. Thus, 18F-FDG PET/CT can serve as a noninvasive tool for precise diagnosis and assist in the preoperative formulation of treatment strategies for patients with incidental CRA.

A population-based analysis on the incidence of metachronous colon cancer after endoscopic resection of advanced adenomas with high-grade dysplasia: does location matter?

BACKGROUND

Advanced adenomas (AAs) with high-grade dysplasia (HGD) represent a risk factor for metachronous neoplasia, with guidelines recommending short-interval surveillance. Although the worse prognosis of proximal (vs distal) colon cancers (CCs) is established, there is paucity of evidence on the impact of laterality on the risk of subsequent neoplasia for these AAs.

METHODS

Adults with HGD adenomas undergoing polypectomy were identified in the Surveillance, Epidemiology, and End Results database (2000-2019). Cumulative incidence of malignancy was estimated using the Kaplan-Meier method. Fine-Gray models assessed the effect of patient and disease characteristics on CC incidence.

RESULTS

Of 3199 patients, 26% had proximal AAs. A total of 65 cases of metachronous adenocarcinoma were identified after polypectomy of 35 proximal and 30 distal adenomas with HGD. The 10-year cumulative incidence of CC was 2.3%; when stratified by location, it was 4.8% for proximal vs 1.4% for distal adenomas. Proximal location was significantly associated with increased incidence of metachronous cancer (adjusted hazard ratio, 3.32; 95% CI, 2.05-5.38).

CONCLUSION

Proximal location of AAs with HGD was associated with >3-fold increased incidence of metachronous CC and shorter time to diagnosis. These data suggest laterality should be considered in the treatment and follow-up of these patients.

Dietary Inflammatory Potential and the Risk of Serrated and Adenomatous Colorectal Polyps

Studies of dietary inflammation potential and risks of colorectal cancer precursors are limited, particularly for sessile serrated lesions (SSLs). This study examines the association using the energy-adjusted dietary inflammatory index (E-DIITM), a measure of anti- and/or pro-inflammatory diet, in a large US colonoscopy-based case-control study of 3246 controls, 1530 adenoma cases, 472 hyperplastic polyp cases, and 180 SSL cases. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived from logistic regression models. Analyses were stratified by participant characteristics, and urinary prostaglandin E2 metabolite (PGE-M) and high-sensitivity plasma C-reactive protein (hs-CRP) levels, inflammation biomarkers. Highest E-DII™ intake was associated with significantly increased risks of colorectal adenomas (OR 1.36, 95% CI 1.11, 1.67), and hyperplastic polyps (OR 1.43, 95% CI 1.06, 1.98), compared with participants consuming the lowest E-DII™ quartile. A similar, but non-significant, increased risk was also observed for SSLs (OR 1.41, 95% CI 0.82, 2.41). The positive association was stronger in females (pinteraction <0.001), normal weight individuals (ptrend 0.01), and in individuals with lower inflammatory biomarkers (ptrend 0.02 and 0.01 for PGE-M and hs-CRP, respectively). A high E-DII™ is associated with colorectal polyp risk, therefore promoting an anti-inflammatory diet may aid in preventing colorectal polyps.

Shape-specific characterization of colorectal adenoma growth and transition to cancer with stochastic cell-based models

Colorectal adenoma are precursor lesions on the pathway to cancer. Their removal in screening colonoscopies has markedly reduced rates of cancer incidence and death. Generic models of adenoma growth and transition to cancer can guide the implementation of screening strategies. But adenoma shape has rarely featured as a relevant risk factor. Against this backdrop we aim to demonstrate that shape influences growth dynamics and cancer risk. Stochastic cell-based models are applied to a data set of 197,347 Bavarian outpatients who had colonoscopies from 2006-2009, 50,649 patients were reported with adenoma and 296 patients had cancer. For multi-stage clonal expansion (MSCE) models with up to three initiating stages parameters were estimated by fits to data sets of all shapes combined, and of sessile (70% of all adenoma), peduncular (17%) and flat (13%) adenoma separately for both sexes. Pertinent features of adenoma growth present themselves in contrast to previous assumptions. Stem cells with initial molecular changes residing in early adenoma predominantly multiply within two-dimensional structures such as crypts. For these cells mutation and division rates decrease with age. The absolute number of initiated cells in an adenoma of size 1 cm is small around 103, related to all bulk cells they constitute a share of about 10-5. The notion of very few proliferating stem cells with age-decreasing division rates is supported by cell marker experiments. The probability for adenoma transiting to cancer increases with squared linear size and shows a shape dependence. Compared to peduncular and flat adenoma, it is twice as high for sessile adenoma of the same size. We present a simple mathematical expression for the hazard ratio of interval cancers which provides a mechanistic understanding of this important quality indicator. We conclude that adenoma shape deserves closer consideration in screening strategies and as risk factor for transition to cancer.

Clinicopathological Correlates of Dysplastic Sessile Serrated Lesion: A Prospective Cohort Study With a High Detection Rate

Background and Aims

Sessile serrated lesions (SSLs) develop colorectal cancer (CRC), through a critical intermediary stage of SSL with dysplasia (SSLd). In this prospective observational study, we aimed to assess clinicopathological correlates of SSLd in the setting of a high lesion-detection rate.

Methods

Patients diagnosed with SSL and SSLd from February 2018 until January 2020 were prospectively recruited, and SSLd specimens were re-evaluated by 2 expert pathologists in a blinded manner. Associations were analyzed using multivariate logistic regression models.

Results

A total of 6425 patients underwent 7423 colonoscopies, and 2671 SSLs were resected from 1047 patients. The overall SSL detection rate per colonoscopy was 15.9%. The median age of patients with SSL was 54 years (interquartile range, 39-66), and 43.3% were male. After pathologist review, 24 SSLds were confirmed in 20 patients. The median size of SSLd was 8 mm (interquartile range, 5.75-15.25), and 13 of 24 SSLds were <10 mm in size. After multivariate analysis, older age (odds ratio = 1.07, 95% confidence interval = 1.03-1.1) and higher number of synchronous SSLs (odds ratio = 1.12, 95% confidence interval = 1.02-1.23) were associated with the presence of dysplasia. Patient sex and number and size of synchronous adenomas were not associated with the presence of SSLd. Seven of 20 patients with SSLd had synchronous or metachronous SSLd. Six of 20 patients with SSLd met the diagnostic criteria for serrated polyposis syndrome.

Conclusion

The overall SSL detection rate was 15.9%, and 0.9% of SSLs were dysplastic. Older age and higher number of synchronous SSL were risk factors for the presence of dysplasia in SSLs. Thirty percent of patients with SSLd had serrated polyposis syndrome, and 35% had multiple SSLd.

Determinants of colorectal cancer screening in Germany: a claims data analysis

With an incidence of 58,000 cases per year, colorectal cancer (CRC) is the third most common type of cancer in Germany. Although guaiac-based fecal occult blood tests (gFOBT) and colonoscopy are accepted strategies for CRC screening offered for individuals aged 50 or 55 onwards, utilization rates remain low.This study examines various determinants for participation in CRC screening using claims data provided by the AOK Niedersachsen and covering the years 2014 to 2016. Using multivariate logistic regression models, we analyzed sociodemographic factors (sex, age, nationality, type of employment) associated with screening behavior, including individuals who underwent colonoscopy or gFOBT. The effect of school education and professional qualification was estimated using subgroups of employees with social insurance.The analysis consisted of 620,977 insured individuals in the study population for screening colonoscopy, while the gFOBT study population contained 845,191 individuals. With increasing age, individuals were less likely to participate in CRC screening. Participation rates for screening were higher for women than men in younger age groups. However, men in higher age groups showed increased participation rates in gFOBT screening. When compared with German citizens, Turkish citizens use the colonoscopy less often and the gFOBT more often. In contrast to employees with social insurance, unemployed individuals accept the prevention services less frequently, whereas pensioners and voluntarily insured individuals exhibit increased participation rates. In terms of education and professional qualification, we estimated a significantly lower participation rate exclusively for the least educated individuals. The results help to better understand patterns of utilization and can contribute to the development of information programs for specific groups.

Histopathological features for coexistent invasive cancer in large colorectal adenomatous polyps

Background

Histopathological features associated with coexistent invasive adenocarcinoma in large colorectal adenomas have not been described. This study aimed to determine the association of histopathological features in areas of low-grade dysplasia with coexistent invasive adenocarcinoma.

Methods

High-grade lesions (containing high-grade dysplasia or adenocarcinoma) from a cohort of large (at least 20 mm) colorectal adenomas removed by endoscopic resection were subjected to detailed histopathological analysis. The histopathological features in low-grade areas with coexistent adenocarcinoma were reviewed and their diagnostic performance was evaluated.

Results

Seventy-four high-grade lesions from 401 endoscopic resections of large adenomas were included. In the low-grade dysplastic areas, a coexistent invasive adenocarcinoma was associated significantly with a cribriform or trabecular growth pattern (P < 0.001), high nuclear grade (P < 0.001), multifocal intraluminal necrosis (P < 0.001), atypical mitotic figures (P = 0.006), infiltrative lesion edges (P < 0.001), a broad fibrous band (P = 0.001), ulceration (P < 0.001), expansile nodules (P < 0.001) and an extensive tumour-infiltrating lymphocyte pattern (P = 0.04). Lesions with coexistent invasive adenocarcinoma harboured at least one of these features. The area under the receiver operating characteristic curve (AUROC) for coexistent invasive adenocarcinoma, using frequencies of adverse histopathological factors in low-grade areas, was 0.92. The presence of two or more of these adverse histopathological features in low-grade areas had a sensitivity of 86 per cent and a specificity of 84 per cent for coexistent invasive adenocarcinoma.

Conclusion

Several histopathological features in low-grade dysplastic areas of adenomas could be predictive of coexistent adenocarcinoma.

The Application of Core Needle Biopsy Through the Trocar Hole in the Surgical Operation of Endoscopically Unresectable Giant Colon Polyps: A Systematic Review Study

INTRODUCTION

The study aimed to investigate the application of core needle biopsy through the trocar hole during surgery on endoscopically unresectable giant colon polyps.

METHODS

The clinical data of 51 patients with endoscopically unresectable giant colon polyps from May 2016 to May 2020 were retrospectively analyzed. The primary observational outcomes were two comparative analyses of pathologic results, using the kappa index: comparison of the pathologic results from the preoperative colonoscopy and the postoperative pathologic results and comparison of the intraoperative pathologic results from core needle biopsy of the intestinal wall and the postoperative pathologic results. The secondary observational outcomes were duration of needle biopsy, operation duration, volume of intraoperative hemorrhage, rate of postoperative wound infection, rate of abdominal cavity infection, length of stay, and number and positivity of lymph node dissections after laparoscopic radical resection of colon cancer.

RESULTS

Poor consistency was found between the preoperative (colonoscopy) and postoperative pathologic results, with kappa = 0.222 (i.e., kappa < 0.4), P < 0.05. However, good consistency was found between the intraoperative (core needle biopsy) and postoperative pathologic results, with kappa = 0.923 (i.e., kappa ≥ 0.75), P < 0.05. The postoperative pathologic results were as follows: 7 cases of adenomatous polyps of the colon, 12 cases of low-grade intraepithelial neoplasia, 12 cases of high-grade intraepithelial neoplasia, and 25 cases of invasive colon cancer. There was no incision infection, no abdominal cavity infection or formation of an abdominal abscess, no anastomotic leakage, and no death for any of the 51 patients. Postoperative complications occurred in two cases (3.92%).

CONCLUSION

Biopsy through the trocar hole during laparoscopic surgery produced highly accurate pathologic results and was a fast, safe, and effective diagnostic method. Pathologic results from intraoperative biopsy could accurately determine the nature of colon polyps and provide a basis for choosing an appropriate surgical scheme.

Standardized Pathology Report for Colorectal Cancer, 2nd Edition

The first edition of the 'Standardized Pathology Report for Colorectal Cancer,' which was developed by the Gastrointestinal Pathology Study Group (GIP) of the Korean Society of Pathologists, was published 13 years ago. Meanwhile, there have been many changes in the pathologic diagnosis of colorectal cancer (CRC), pathologic findings included in the pathology report, and immunohistochemical and molecular pathology required for the diagnosis and treatment of colorectal cancer. In order to reflect these changes, we (GIP) decided to make the second edition of the report. The purpose of this standardized pathology report is to provide a practical protocol for Korean pathologists, which could help diagnose and treat CRC patients. This report consists of "standard data elements" and "conditional data elements." Basic pathologic findings and parts necessary for prognostication of CRC patients are classified as "standard data elements," while other prognostic factors and factors related to adjuvant therapy are classified as "conditional data elements" so that each institution could select the contents according to the characteristics of the institution. The Korean version is also provided separately so that Korean pathologists can easily understand and use this report. We hope that this report will be helpful in the daily practice of CRC diagnosis.

Surgical or endoscopic management of malignant colon polyps

BACKGROUND

To evaluate indications for colectomy in T1 polyps and possible risk factors for lymph node metastasis.

METHODS

Between 2004 and 2017, 40 patients underwent colectomy after endoscopic removal of malignant polyps with T1 carcinoma. Resection was done based on at least one of the unfavourable histopathological criteria. We collected and prospectively studied histopathologic features, short-term results and the benefit-risk balance. Complications were assessed by Clavien-Dindo classification.

RESULTS

Twenty-five patients (62.5%) underwent laparoscopic bowel resection. Twenty-nine patients (63.0%) had more than two unfavourable criteria in the polyp that justified colorectal resection. Thirty-five patients (76%) had G2 (moderately differentiated) cancer, 11 (24%) had G1 (well-differentiated). Five patients (12.5%) had lymph node metastases and one (2.5%) had residual adenocarcinoma. All five patients with lymph node metastasis had G2 cancer. Nine patients (22.5%) had residual adenoma. Overall complications were identified in six (15.0%) patients. Oncologic benefit (or risk factors for lymph node metastasis) was significantly associated with polyp size ≥18 mm (P = 0.006), lymphovascular invasion (P = 0.05) and budding (P = 0.02).

CONCLUSIONS

Female gender, lymphovascular invasion, desmoplastic reaction, criteria for surgery ≥2 and polyp size ≥18 mm were all in complex significant risk factors for lymph node metastasis in T1 colorectal cancer. Acting as a single factor, these variables had no effect to increased risk of metastasis.

Proteomics for early detection of colorectal cancer: recent updates

INTRODUCTION

Colorectal cancer (CRC) is a common type of cancer with a relatively poor survival rate. The survival rate of patients could be improved if CRC is detected early. Biomarkers associated with early stages of tumor development might provide useful tools for the early diagnosis of colorectal cancer. Areas covered: Online searches using PubMed and Google Scholar were performed using keywords and with a focus on recent proteomic studies. The aim of this review is to highlight the need for biomarkers to improve the detection rate of early CRC and provide an overview of proteomic technologies used for biomarker discovery and validation. This review will also discuss recent proteomic studies which focus on identifying biomarkers associated with the early stages of CRC development. Expert commentary: A large number of CRC biomarkers are increasingly being identified by proteomics using diverse approaches. However, the clinical relevance and introduction of these markers into clinical practice cannot be determined without a robust validation process. The size of validation cohorts remains a major limitation in many biomarker studies.

XB130 enhances invasion and migration of human colorectal cancer cells by promoting epithelial‑mesenchymal transition

The expression of XB130 is associated with invasion and migration of many tumor cells, but its roles in human colorectal cancer (CRC) remains unknown. To investigate this, protein expression levels of XB130 in numerous human CRC cell lines were compared with a normal colorectal mucosa cell line by western blotting. Knockdown of XB130 using small interfering (si)RNA was performed to assess the effects on cell invasion and migration in a Transwell assay and a scratch test. Western blotting was also used to quantify the levels of proteins associated with epithelial‑mesenchymal transition (EMT), including E‑cadherin, vimentin, phosphorylated (p)‑protein kinase B (AKT), p‑forkhead homeobox type O 3a (FOXO3a) and zinc finger E‑box‑binding homeobox 1 (ZEB‑1). The relative expression of XB130 protein was significantly higher in CRC cells compared with control cells (P<0.01). Knockdown of XB130 using siRNA significantly decreased the invasive and migratory responses of CRC cells (P<0.01). In addition, levels of E‑cadherin were increased, while vimentin, p‑AKT, p‑FOXO3a and ZEB‑1 were decreased (P<0.01). In conclusion, the present study demonstrated that the expression of XB130 is elevated in CRC cells. Loss of XB130 was associated with decreased invasion and migration of CRC cells, possibly as a result of EMT inhibition. Thus, upregulation of XB130 may underlie some of the tumorigenic events observed in human CRCs. XB130 may be a promising target for CRC therapy in humans; further mechanistic studies exploring the function of XB130 in CRC cells are warranted.

Genetic Biopsy for Prediction of Surveillance Intervals after Endoscopic Resection of Colonic Polyps: Results of the GENESIS Study

Background and objective

Current surveillance strategies for colorectal cancer following polypectomy are determined by endoscopic and histopathological factors. Such a distinction has been challenged. The present study was designed to identify molecular parameters in colonic polyps potentially defining new sub-groups at risk.

Methods

One hundred patients were enrolled in this multicentre study. Polyps biopsies underwent formalin-free processing (PAXgene, PreAnalytiX) and targeted next generation sequencing (38 genes (QIAGEN), NextSeq 500 platform (Illumina)). Genetic and histopathological analyses were done blinded to other data.

Results

In 100 patients, 224 polyps were removed. Significant associations of genetic alterations with endoscopic or histological polyp characteristics were observed for BRAF, KRAS, TCF7L2, FBXW7 and CTNNB1 mutations. Multivariate analysis revealed that polyps ≥ 10 mm have a significant higher relative risk for harbouring oncogene mutations (relative risk 3.467 (1.742-6.933)). Adenomas and right-sided polyps are independent risk factors for CTNNB1 mutations (relative risk 18.559 (2.371-145.245) and 12.987 (1.637-100.00)).

Conclusions

Assessment of the mutational landscape of polyps can be integrated in the workflow of current colonoscopy practice. There are distinct genetic patterns related to polyp size and location. These results suffice to optimise individual risk calculation and may help to better define surveillance intervals.

Integrative analysis of the colorectal cancer proteome: potential clinical impact

INTRODUCTION

Colorectal cancer (CRC) is one of the common types of cancer that affects a significant proportion of the population and is a major contributor to cancer related mortality. The relatively poor survival rate of CRC could be improved through the identification of clinically useful biomarkers. Areas covered: This review highlights the need for biomarkers and discusses recent proteomics discoveries in the aspects of CRC clinical practice including diagnosis, prognosis, therapy, screening and molecular pathological epidemiology (MPE). Studies have been evaluated in relation to biomarker target, methodology, sample selection, limitations, and potential impact. Finally, the progress in proteomic approaches is briefly discussed and the main difficulties facing the translation of proteomics biomarkers into the clinical practice are highlighted. Expert commentary: The establishment of specific guidelines, best practice recommendations and the improvement in proteomic strategies will significantly improve the prospects for developing clinically useful biomarkers.

[Pathogenetic aspects in precursor lesions of gastrointestinal tumors]

The pathogenesis of precursor lesions of gastrointestinal tumors is manifested in many ways. In the esophagus an aberrant genetic expression of intestinal transcription factors, such as CDX2 is initiated by local environment factors. During the subsequent dysplasia to carcinoma sequence, chromosomal gain and loss of genes occurs. A 4-color fluorescence in situ hybridization (FISH) assay can be applied in dysplasia as well as in Barrett's adenocarcinoma to define prognostic marker combinations. In the gastric carcinogenesis sequence the gene expression of CDX1 is regulatively dependent on an interplay between inflammation and promotor methylation. In the colon sessile serrated adenomas show a sequence with initial BRAF mutation and late onset of MLH1 promotor hypermethylation with consecutive potential cancer progression. This event is accompanied by an increase of intraepithelial lymphocytes, which is an easy to use tool for routine diagnostics using H&E sections. Next generation sequencing (NGS) investigations of germline mutations in colorectal cancer revealed a spectrum of mutations with low penetration in the field of mismatch repair proteins as well as the APC gene. An individual risk stratification for penetration of these germline mutations is necessary. In conclusion, genetics, phenotypes and terminology of gastrointestinal precursor lesions are unified to a mutually influencing concept within medicine.