p53 gene mutation and protein accumulation during neoplastic progression in Barrett's esophagus

RACK1 promotes the occurrence and progression of cervical carcinoma

BACKGROUND

RACK1 has been identified as a multifunctional cytosolic protein, and plays a pivotal role in multiple biological responses involved in several kinds of tumors, while its effect in cervical cancer has not been well elucidated yet. The study aimed to investigate the role of RACK1 in cervical cancer occurrence and progression.

METHODS

The expression of RACK1 in cervical specimens was measured by immunohistochemical staining and Western blot assay. Transgenic mice were used to detect the role of RACK1 in modulating tumorigenesis in vivo. Cervical carcinoma cell lines were used to explore the underlying mechanisms of RACK1 on the behaviors of tumor cells in vitro.

RESULTS

We found that RACK1 expression was upregulated in cancer tissues compared with adjacent tissues, and its expression was gradually increased from cervictis, and cervical intraepithelial neoplasis (CIN) to carcinoma. Genetic overexpression of RACK1 facilitated tumor formation and growth in nude mice. Mechanism studies disclosed that RACK1 over-expression prolonged the G0 /G1 phase by up-regulating the expression of cyclinD1, down-regulating p21 and p27 probably by modulating the phosphorylation of AKT.

CONCLUSIONS

Taken together, we concluded that RACK1 stimulates tumorigenesis and progression of cervical cancer via modulating the proliferation of tumor cells, implying that targeting RACK1 may serve as a promising method for cervical cancer therapy.

Diagnostic Challenges during Inflammation and Cancer: Current Biomarkers and Future Perspectives in Navigating through the Minefield of Reactive versus Dysplastic and Cancerous Lesions in the Digestive System

In the setting of pronounced inflammation, changes in the epithelium may overlap with neoplasia, often rendering it impossible to establish a diagnosis with certainty in daily clinical practice. Here, we discuss the underlying molecular mechanisms driving tissue response during persistent inflammatory signaling along with the potential association with cancer in the gastrointestinal tract, pancreas, extrahepatic bile ducts, and liver. We highlight the histopathological challenges encountered in the diagnosis of chronic inflammation in routine practice and pinpoint tissue-based biomarkers that could complement morphology to differentiate reactive from dysplastic or cancerous lesions. We refer to the advantages and limitations of existing biomarkers employing immunohistochemistry and point to promising new markers, including the generation of novel antibodies targeting mutant proteins, miRNAs, and array assays. Advancements in experimental models, including mouse and 3D models, have improved our understanding of tissue response. The integration of digital pathology along with artificial intelligence may also complement routine visual inspections. Navigating through tissue responses in various chronic inflammatory contexts will help us develop novel and reliable biomarkers that will improve diagnostic decisions and ultimately patient treatment.

Defining an abnormal p53 immunohistochemical stain in Barrett's oesophagus-related dysplasia: a single-positive crypt is a sensitive and specific marker of dysplasia

AIMS

p53 is an independent risk stratification marker in Barrett's oesophagus (BE), but no universally accepted definition exists for abnormal p53 staining. Herein, we assess p53 stains in two cohorts to: (1) define abnormal p53 staining in BE-related dysplasia (BERD) and (2) assess the specificity and sensitivity of this cut-point for the diagnosis of dysplasia.

METHODS

Cohort 1 (n = 313) included (1) dysplastic BE biopsies, (2) prior non-dysplastic BE (NDBE) biopsies from the same patients and (3) NDBE biopsies from patients who never progressed to dysplasia. Cohort 2 (n = 191) consisted of BE biopsies in which p53 staining aided in diagnosing dysplasia. Automated p53 staining quantification was performed on cohort 1. A semiquantitative p53 analysis, performed on both cohorts, included: (1) number of strongly positive glands, (2) strong glandular surface staining, (3) percentage of strongly positive glands and (4) null phenotype.

RESULTS

NDBE biopsies from cohort 1 patients who progressed to dysplasia were more likely to show p53 positivity than non-progressors (16.9 versus 0.6%) (P = 0.0001). The optimal quantitative cut-point for distinguishing dysplastic from never-dysplasia biopsies was 10 strongly positive cells. By semiquantitative analysis, a single strongly p53-positive gland distinguished dysplastic from never-dysplasia BE (sensitivity 98.6%, specificity 99.4%). The semiquantitative and quantitative analyses correlated (P = 0.0001). In cohort 2, the sensitivity and specificity for BERD of ≥ 1 strongly positive p53 gland were 86.0 and 88.6%.

CONCLUSIONS

A single strongly positive p53 gland is sensitive and specific for BERD. Automated p53 analysis may reduce subjectivity associated with the diagnosis of BERD.

Tumors of the Nose and Paranasal Sinuses: Promoting Factors and Molecular Mechanisms-A Systematic Review

Sinonasal neoplasms are uncommon diseases, characterized by heterogeneous biological behavior, which frequently results in challenges in differential diagnosis and treatment choice. The aim of this review was to examine the pathogenesis and molecular mechanisms underlying the regulation of tumor initiation and growth, in order to better define diagnostic and therapeutic strategies as well as the prognostic impact of these rare neoplasms. A systematic review according to Preferred Reporting Items for Systematic Review and Meta-Analysis criteria was conducted between September and November 2022. The authors considered the three main histological patterns of sinonasal tumors, namely Squamous Cell Carcinoma, Intestinal-Type Adenocarcinoma, and Olfactory Neuroblastoma. In total, 246 articles were eventually included in the analysis. The genetic and epigenetic changes underlying the oncogenic process were discussed, through a qualitative synthesis of the included studies. The identification of a comprehensive model of carcinogenesis for each sinonasal cancer subtype is needed, in order to pave the way toward tailored treatment approaches and improve survival for this rare and challenging group of cancers.

Targeted genetic and epigenetic profiling of esophageal adenocarcinomas and non-dysplastic Barrett's esophagus

Background

Despite the efforts to describe the molecular landscape of esophageal adenocarcinoma (EAC) and its precursor lesion Barrett’s esophagus (BE), discrepant findings are reported. Here, we investigated the prevalence of selected genetic (TP53 mutations and microsatellite instability (MSI) status) and epigenetic (DNA promoter hypermethylation of APC, CDKN2A, MGMT, TIMP3 and MLH1) modifications in a series of 19 non-dysplastic BE and 145 EAC samples. Additional biopsies from adjacent normal tissue were also evaluated. State-of-the-art methodologies and well-defined scoring criteria were applied in all molecular analyses.

Results

Overall, we confirmed frequent TP53 mutations among EAC (28%) in contrast to BE, which harbored no mutations. We demonstrated that MSI and MLH1 promoter hypermethylation are rare events, both in EAC and in BE. Our findings further support that APC, CDKN2A, MGMT and TIMP3 promoter hypermethylation is frequently seen in both lesions (21–89%), as well as in a subset of adjacent normal samples (up to 12%).

Conclusions

Our study further enlightens the molecular background of BE and EAC. To the best of our knowledge, this is one of the largest studies addressing a targeted analysis of genetic and epigenetic modifications simultaneously across a combined series of non-dysplastic BE and EAC samples.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-022-01287-7.

Expansion of gastric intestinal metaplasia with copy number aberrations contributes to field cancerization

Intestinal metaplasia (IM) is a risk factor for gastric cancer following infection with Helicobacter pylori. To explore the susceptibility of pure gastric IM to cancer development, we investigated genetic alterations in single IM gastric glands. We isolated 50 single IM or non-IM glands from the inflamed gastric mucosa of 11 patients with intramucosal gastric carcinoma (IGC) and 4 patients without IGC; nineteen single glands in the non-inflamed gastric mucosa of 11 individuals from our cohort and previous dataset were also included as controls. Whole exome sequencing of single glands revealed significantly higher accumulation of somatic mutations in various genes within IM glands compared with non-IM glands. Clonal ordering analysis showed that IM glands expanded to form clusters with shared mutations. Additionally, targeted-capture deep sequencing and copy number (CN) analyses were performed in 96 clustered IM or non-IM gastric glands from 26 patients with IGC. CN analyses were also performed on 41 IGC samples and the Cancer Genome Atlas-Stomach Adenocarcinoma datasets. These analyses revealed that polyclonally expanded IM commonly acquired copy number aberrations (CNA), including amplification of chromosomes 8, 20, and 2. A large portion of clustered IM glands typically consisted of common CNAs rather than other cancer-related mutations. Moreover, the CNA patterns of clustered IM glands were similar to those of IGC, indicative of precancerous conditions. Taken together, these findings suggest that, in the gastric mucosa inflamed with H. pylori infection, IM glands expand via acquisition of CNAs comparable to those of IGC, contributing to field cancerization.

Utility of ancillary studies in the diagnosis and risk assessment of Barrett's esophagus and dysplasia

Barrett's esophagus (BE) is a major risk factor for the development of esophageal adenocarcinoma (EAC). BE patients undergo periodic endoscopic surveillance with biopsies to detect dysplasia and EAC, but this strategy is imperfect owing to sampling error and inconsistencies in the diagnosis and grading of dysplasia, which may result in an inaccurate diagnosis or risk assessment for progression to EAC. The desire for more accurate diagnosis and better risk stratification has prompted the investigation and development of potential biomarkers that might assist pathologists and clinicians in the management of BE patients, allowing more aggressive endoscopic surveillance and treatment options to be targeted to high-risk individuals, while avoiding frequent surveillance or unnecessary interventions in those at lower risk. It is known that progression of BE to dysplasia and EAC is accompanied by a host of genetic alterations, and that exploration of these markers could be potentially useful to diagnose/grade dysplasia and/or to risk stratify BE patients. Several biomarkers have shown promise in identifying early neoplastic transformation and thus may be useful adjuncts to histologic evaluation. This review provides an overview of some of the currently available biomarkers and assays, including p53 immunostaining, Wide Area Transepithelial Sampling with Three-Dimensional Computer-Assisted Analysis (WATS^3D), TissueCypher, mutational load analysis (BarreGen), fluorescence in situ hybridization, and DNA content abnormalities as detected by DNA flow cytometry.

The path(ology) from reflux oesophagitis to Barrett oesophagus to oesophageal adenocarcinoma

This review seeks to summarise the steps in the path from reflux oesophagitis to Barrett oesophagus to oesophageal adenocarcinoma. The epidemiology, clinical presentation, definitions, pathological features, diagnostic pitfalls, and emerging concepts are reviewed for each entity. The histological features of reflux oesophagitis can be variable and are not specific. Cases of reflux oesophagitis with numerous eosinophils are difficult to distinguish from eosinophilic oesophagitis and other oesophagitides with eosinophils (Crohn's disease, medication effect, and connective tissue disorders). In reflux oesophagitis, the findings are often most pronounced in the distal oesophagus, the eosinophils are randomly distributed throughout the epithelium, and eosinophilic abscesses and degranulated eosinophils are rare. For reflux oesophagitis with prominent lymphocytes, clinical history and ancillary clinical studies are paramount to distinguish reflux oesophagitis from other causes of lymphocytic oesophagitis pattern. For Barrett oesophagus, the definition remains a hotly debated topic for which the requirement for intestinal metaplasia to make the diagnosis is not applied unanimously across the globe. Assessing for dysplasia is a challenging aspect of the histological interpretation that guides clinical management. We describe the histological features that we find useful in making this evaluation. Oesophageal adenocarcinoma has been steadily increasing in incidence and has a poor prognosis. The extent of invasion can be overdiagnosed due to a duplicated muscularis mucosae. We also describe the technical factors that can lead to challenges in distinguishing the mucosal and deep margins of endoscopic resections. Lastly, we give an overview of targeted therapies with emerging importance and the ancillary tests that can identify the cases best suited for each therapy.

Expression of p53, p63, podoplanin and Ki-67 in recurring versus non-recurring oral leukoplakia

Oral leukoplakia (OL), a potentially malignant disorder, recurs in 40% of cases after surgical removal. Recurrence is a risk factor for malignant transformation. We aimed to examine the prognostic significance of four biomarkers related to cell proliferation: p53, p63, podoplanin (PDPN) and Ki-67 in predicting recurrence. Formalin-fixed-paraffin-embedded specimens from excised OL (n = 73, 33 recurrent; 40 non-recurrent) were collected in a prospective study. Immunohistochemistry was used to visualise expression of p53, p63, PDPN and Ki-67. Image analysis software was used for quantification of p53-, p63- and Ki-67-expressing cells, while PDPN was analysed visually. The expression of all four proteins were higher in recurrent compared with non-recurrent OL, only expression of p53 was statistically significant. In uni- and multivariable Cox regression analyses of individual markers, expression of p63 was significantly associated with higher recurrence risk (p = 0.047). OL with a combined high expression of both p53 and p63 had a significantly higher risk to recur [Log Rank, p = 0.036; multivariate Cox, HR: 2.48 (1.13–5.44; p = 0.024)]. Combination of p53 and p63 expression may be used as a prognostic biomarker for recurrence of OL.

p53 overexpression is a prognosticator of poor outcome in esophageal cancer

Immunohistochemistry studies on p53 inactivation in esophageal cancer are available with inconclusive results. Data on the combined effect of p53 protein accumulation and TP53 genomic deactivation in large scale studies for esophageal cancer are currently lacking. A tissue microarray with 691 esophageal cancer samples was analyzed by p53 immunohistochemistry and fluorescence in situ hybridization (FISH). Nuclear p53 accumulation was observed in 45.9% of patients with adenocarcinoma (AC) and in 40.0% in squamous cell carcinoma (SCC). Heterozygous TP53 deletions occurred in 40.9% in AC and in 19.4% in SCC. Homozygous deletions did not occur at all. High-level p53 immunostaining was associated with shortened overall survival in AC and SCC while TP53 deletions alone showed no correlation with survival. High-level p53 immunostaining in patients with AC was associated with advanced tumor (P=0.019) and Union for International Cancer Control stages (P=0.004), grading (P=0.027) and the resection margin status (P=0.006). Associations between p53 immunostaining and SCC were not found. TP53 deletions were found to be associated with advanced tumor stages (P=0.028) and the presence of lymph node metastasis (P=0.009) in SCC. In conclusion, strong p53 immunostaining, but not TP53 deletion alone, is associated with unfavorable outcomes and may therefore represent a clinically useful molecular marker in esophageal cancer.

Centrosome amplification arises before neoplasia and increases upon p53 loss in tumorigenesis

Lopes et al. examine centrosomes in human samples progressing from premalignant to metastatic lesions from patients with Barrett’s esophagus. They find that centrosome amplification can occur before transformation during human tumorigenesis, being repressed by p53, suggesting that centrosome amplification contributes to tumor initiation before p53 mutation.

Centrosome abnormalities are a typical hallmark of human cancers. However, the origin and dynamics of such abnormalities in human cancer are not known. In this study, we examined centrosomes in Barrett’s esophagus tumorigenesis, a well-characterized multistep pathway of progression, from the premalignant condition to the metastatic disease. This human cancer model allows the study of sequential steps of progression within the same patient and has representative cell lines from all stages of disease. Remarkably, centrosome amplification was detected as early as the premalignant condition and was significantly expanded in dysplasia. It was then present throughout malignant transformation both in adenocarcinoma and metastasis. The early expansion of centrosome amplification correlated with and was dependent on loss of function of the tumor suppressor p53 both through loss of wild-type expression and hotspot mutations. Our work shows that centrosome amplification in human tumorigenesis can occur before transformation, being repressed by p53. These findings suggest centrosome amplification in humans can contribute to tumor initiation and progression.

Targeted Single Gene Mutation in Esophageal Adenocarcinoma

Esophageal adenocarcinoma is heterogeneous and studies have reviewed many important mutations that contribute to the pathogenesis of the cancer. These discoveries have helped paved the way into identifying new gene markers or gene targets to develop novel molecular directed therapy for better patient outcomes in esophageal adenocarcinoma. Despite the recent bloom in next-generation sequencing, Sanger sequencing still represents the gold standard method for the study of the driver genes in esophageal adenocarcinoma. This chapter focuses on the sequencing techniques in identification of single gene mutations.

PAX5 gene as a novel methylation marker that predicts both clinical outcome and cisplatin sensitivity in esophageal squamous cell carcinoma

Therapeutic strategies for esophageal cancer largely depend on histopathological assessment. To select appropriate treatments of individual patients, we examined the background molecular characteristics of tumor malignancy and sensitivity to multidisciplinary therapy. Seventy-eight surgically-resected esophageal squamous cell carcinoma (ESCC) cases during 2001-2013 were examined. PAX5, a novel gene methylation marker in ESCC, was evaluated in the specimens, as methylation of this gene was identified as an extremely tumor-specific event in squamous cell carcinogenesis of head and neck. PAX5 methylation status was evaluated by quantitative MSP (QMSP) assays. Mean QMSP value was 15.7 (0-136.3) in ESCCs and 0.3 (0-8.6) in adjacent normal tissues (P < 0.001). The 78 cases were divided into high QMSP value (high QMSP, n = 26) and low QMSP value (low QMSP, n = 52). High QMSP cases were significantly associated with downregulated PAX5 expression (P = 0.040), and showed significantly poor recurrence-free survival [Hazard Ratio (HR) = 2.84; P = 0.005; 95% Confidence Interval (CI): 1.39-5.81] and overall survival (HR = 3.23; P = 0.002; 95%CI: 1.52-7.01) in multivariable analyses with histopathological factors. PAX5-knockdown cells exhibited significantly increased cell proliferation and cisplatin resistance. PAX5 gene methylation can predict poor survival outcomes and cisplatin sensitivity in ESCCs and could be a useful diagnostic tool for cancer therapy selection.

Expression of p53 protein in high-grade gastroenteropancreatic neuroendocrine carcinoma

BACKGROUND

Gastroenteropancreatic neuroendocrine carcinomas (GEP-NECs) are aggressive, rapidly proliferating tumors. Therapeutic response to current chemotherapy regimens is usually short lasting. The aim of this study was to examine the expression and potential clinical importance of immunoreactive p53 protein in GEP-NEC.

MATERIALS AND METHODS

Tumor tissues from 124 GEP-NEC patients with locally advanced or metastatic disease treated with platinum-based chemotherapy were collected from Nordic centers and clinical data were obtained from the Nordic NEC register. Tumor proliferation rate and differentiation were re-evaluated. All specimens were immunostained for p53 protein using a commercially available monoclonal antibody. Kaplan-Meier curves and cox regression analyses were used to assess progression-free survival (PFS) and overall survival (OS).

RESULTS

All tumor tissues were immunoreactive for either one or both neuroendocrine biomarkers (chromogranin A and synaptophysin) and Ki67 index was >20% in all cases. p53 immunoreactivity was only shown in 39% of the cases and was not found to be a prognostic marker for the whole cohort. However, p53 immunoreactivity was correlated with shorter PFS in patients with colorectal tumors (HR = 2.1, p = 0.03) in a univariate analysis as well as to poorer PFS (HR = 2.6, p = 0.03) and OS (HR = 3.4, p = 0.02) in patients with colorectal tumors with distant metastases, a correlation which remained significant in the multivariate analyses.

CONCLUSION

In this cohort of GEP-NEC patients, p53 expression could not be correlated with clinical outcome. However, in patients with colorectal NECs, p53 expression was correlated with shorter PFS and OS. Further studies are needed to establish the role of immunoreactive p53 as a prognostic marker for GEP-NEC patients.

Her-2 Expression in Gastroesophageal Intestinal Metaplasia, Dysplasia, and Adenocarcinoma

Overexpression of human epidermal growth factor receptor 2 protein (Her-2) in Barrett neoplasia is significant for targeted therapy with trastuzumab. Here, we studied the frequency of Her-2 overexpression in Barrett adenocarcinoma and precursor lesions. Retrospective formalin-fixed paraffin-embedded tissue samples of 25 normal (NM) esophageal mucosa, 50 Barrett esophagus (BE) without dysplasia, 49 BE with low-grade dysplasia (LGD), 50 BE with high-grade dysplasia (HGD), and 50 invasive adenocarcinoma (ICA) were used. A BE tissue microarray was built and analyzed by Her-2 immunohistochemistry (IHC) and Her-2 dual in situ hybridization (DISH). Her-2 IHC expression was negative in NM and low in 26% of BE (IHC score: 1+) and in 24.5% of LGD (IHC score: 1 to 2+). Her-2 overexpression was seen in 28% of HGD and in 24% of ICA (IHC score: 2 to 3+). Her-2 DISH was negative in NM and BE but positive in 6% of LGD, 20% of HGD, and 18% of ICA. Differences in Her-2 DISH positivity between NM and HGD or ICA were statistically significant (P = 0.02), but those between NM and LGD or HGD and ICA were not (P = 0.2). Although Her-2 overexpression results in ICA were similar to previous reports, the finding of 28% in HGD was unexpected and may have clinical implications. Positive Her-2 DISH in 6% of LGD is novel, suggesting a role of Her-2 during BE progression.

Adenocarcinoma of Barrett's esophagus in a dog

An endoscopic examination revealed a mass in the distal esophagus of a 9-year-old intact male bulldog. Histopathologically, the mass was composed of cuboidal to columnar neoplastic epithelial cells and extended from the squamous epithelium of the esophageal mucosa, indicating that the tumor was derived from Barrett’s esophagus. Moreover, highly atypical foci that exhibited a cribriform pattern and high mitotic indices were also observed. The epithelial cells on the surface of the lesion often produced mucus that was positive for Alcian blue and immunohistochemically positive for MUC5AC. The neoplastic epithelial cells were diffusely positive for cytokeratin 7 and p53, and occasionally positive for cytokeratin 20. Based on these findings, the tumor was diagnosed as an adenocarcinoma. This report describes the clinical and pathological features of a spontaneous case of adenocarcinoma of Barrett’s esophagus in a dog.

Morphological Features and Prognostic Significance of ARID1A-Deficient Esophageal Adenocarcinomas

Context.—

The clinicopathologic and prognostic significance of ARID1A mutation in esophageal adenocarcinoma (EAC) is unknown.

Objective.—

To determine the morphological correlates and prognostic significance of ARID1A-deficient EAC.

Design.—

One hundred twenty cases of primary EAC were evaluated for a predetermined set of histologic features and immunohistochemistry for ARID1A, p53, and MLH1 performed on EAC, as well as adjacent Barrett esophagus and Barrett esophagus–associated dysplasia, when feasible. Associations between categorical clinicopathologic variables were analyzed by Fisher exact test, and survival analysis was performed by a Cox proportional hazards analysis.

Results.—

The study group included 97 men and 23 women (mean age, 66 years). Loss of ARID1A expression was seen in 12 of 120 EACs (10%). ARID1A-deficient tumors showed a strong correlation with a medullary and mucinous phenotype, and 8 of 12 (67%) had at least one feature reminiscent of high microsatellite instability colon carcinomas (mucinous or medullary differentiation, marked intratumoral or peritumoral lymphoid infiltrate). A mutant p53 pattern was present in 52 of 120 EACs (43%) and showed no correlation with ARID1A deficiency (P &gt; .05). MLH1 loss was present in only 2 of 120 EACs (2%); both of which were also deficient in ARID1A. ARID1A-deficient EACs showed a trend toward increased risk of nodal metastasis but had no effect on overall patient survival.

Conclusions.—

ARID1A-deficient EACs show a phenotype similar to colon cancer with high microsatellite instability but do not appear to have any prognostic significance. Concurrent MLH1 loss is not seen in most ARID1A-deficient tumors, suggesting that ARID1A may be a primary driver of carcinogenesis in a subset of EACs.

Radiofrequency ablation for low-grade dysplasia in Barrett's esophagus

PURPOSE OF REVIEW

The diagnosis and management of low-grade dysplasia (LGD) in Barrett's esophagus continue to evolve and vary in practice. Radiofrequency ablation (RFA) is now an acceptable option for the treatment of LGD. Therefore, the purpose of this review article is to present current literature on the diagnosis and management of LGD, and to explore when to optimally pursue RFA for the treatment of LGD.

RECENT FINDINGS

The challenge of the management of LGD begins with its diagnosis. Because of high interobserver variability among pathologists in the diagnosis of dysplasia, it is recommended that an expert gastrointestinal pathologist confirms the diagnosis of LGD. Endoscopic mucosal resection is indicated to remove visible lesions in the setting of dysplasia to obtain an accurate diagnosis, especially regarding T staging. Management options include intense surveillance and endoscopic eradication therapy. RFA provides a reasonable method to eradicate flat Barrett's mucosa. Endoscopic eradication of confirmed LGD has been demonstrated to reduce the risk of progression to esophageal cancer. Additional data about the risk factors associated with progression, and the benefits and risks of treatment are discussed, and can be incorporated in patient counseling and decision making.

SUMMARY

Endoscopic eradication therapy with RFA may be an appropriate treatment option for LGD in Barrett's esophagus after the benefits and risks have been discussed in detail with the patient.

Strong NFκB Expression is Associated With High-grade Dysplasia in Barrett's Esophagus

Nuclear factor kappa B (NFκB) is a transcription factor that regulates the activation of genes involved in proinflammatory response and growth. In this study, we utilized immunohistochemical stains for 2 of the NFκB molecules (RELA and NFκB-1) to evaluate the expression of NFκB in Barrett's esophagus (BE). Forty-three cases of BE [17 cases with no dysplasia, 16 cases with low-grade dysplasia (LGD), and 10 cases with high-grade dysplasia (HGD)], 10 normal esophageal biopsies, and 9 cases of esophageal adenocarcinoma were evaluated. Expression of NFκB-1 and RELA did not occur in normal esophageal squamous mucosa. BE without dysplasia showed weak expression of RELA and NFκB-1 in 35% and 65% of cases, respectively. BE with LGD showed weak expression of RELA and NFκB-1 in 50% and 75% of cases, respectively. Strong expression of RELA and NFκB-1 did not occur in BE without dysplasia or with LGD. BE with HGD showed strong expression of RELA and NFκB-1 in 80% and 90% of cases, respectively. All cases of adenocarcinoma showed strong expression of both RELA and NFκB-1. There was a progressive increase in staining intensity of RELA and NFκB-1 along the metaplasia-dysplasia-adenocarcinoma pathway. Strong expression of NFκB is associated with HGD and adenocarcinoma (P<0.0001). We showed that strong expression of NFκB-1 and RELA correlates highly with BE with HGD and adenocarcinoma.

Surgical and Molecular Pathology of Barrett Esophagus

BACKGROUND

Patients with Barrett esophagus (BE) are predisposed to developing dysplasia and cancer. Adenocarcinoma, which is associated with BE, is the most common type of esophageal tumor and, typically, it has an aggressive clinical course and a high rate of mortality.

METHODS

The English-language literature relating to tumor epidemiology, etiology, and the pathogenesis of BE was reviewed and summarized.

RESULTS

The role of pathologists in the diagnosis and pitfalls associated with grading Barrett dysplasia is addressed. Current molecular testing for Barrett neoplasia, as well as testing methods currently in development, is discussed, focusing on relevant tests for diagnosing tumor types, determining prognosis, and assessing therapeutic response.

CONCLUSIONS

Grading is essential for developing appropriate treatment plans, follow-up visits, and therapeutic interventions for each patient. Familiarity with current molecular testing methods will help physicians correctly diagnose the disease and select the most appropriate therapy for each of their patients.

Uterine Carcinomas in Tetrabromobisphenol A-exposed Wistar Han Rats Harbor Increased Tp53 Mutations and Mimic High-grade Type I Endometrial Carcinomas in Women

Endometrial carcinoma is the most common gynecologic malignancy is the United States and accounts for 6% of all cancers in women. The disease is classified as type I or type II based on clinicopathologic and molecular features. It is a multifactorial disease with a number of risk factors, including environmental exposures. How environmental exposures, such as flame retardants, may affect the incidence of endometrial cancer is a topic of current and ongoing interest. Tetrabromobisphenol A (TBBPA) is a widely used brominated flame retardant found in a variety of household products. A recent 2-year National Toxicology Program carcinogenicity study found that exposure to TBBPA was associated with a marked increase in the development of uterine tumors, specifically uterine carcinomas, in Wistar Han rats. Molecularly, TBBPA-induced uterine carcinomas in Wistar Han rats were characterized by a marked increase in tumor protein 53 mutation compared to spontaneous uterine carcinomas, as well as overexpression of human epidermal growth factor receptor 2. Similar to spontaneous carcinomas, tumors in TBBPA-exposed rats were estrogen receptor-alpha positive and progesterone receptor negative by immunohistochemistry. The morphologic and molecular features of uterine carcinomas in TBBPA-exposed rats resemble those of high-grade type I tumors in women, and these data suggest that exposure to TBBPA may pose an increased cancer risk.

Expression of p53 predicts risk of prevalent and incident advanced neoplasia in patients with Barrett's esophagus and epithelial changes indefinite for dysplasia

Background and aims: Patients with Barrett’s esophagus (BE) are at an increased risk for developing esophageal adenocarcinoma (EAC); thus they may undergo regular endoscopic surveillance. If epithelial changes cannot be unequivocally classified as negative or positive for dysplasia, a diagnosis of indefinite for dysplasia (IND) is recommended. Several biomarkers have been proposed as markers or predictors of neoplasia in the general BE population; however, their significance is not clear in patients with BE-IND. We therefore performed a retrospective study to determine whether expression of these biomarkers was associated with the development of neoplasia in BE-IND patients.

Methods: We searched our archives to identify all cases of BE-IND diagnosed between January 1992 and December 2007. Immunohistochemical analyses were used to semi-quantify the expression of p53, α-methylacyl-CoA racemase (AMACR), and cyclin D1. A univariate analysis was used to identify predictors for prevalent and incident neoplasia and advanced neoplasia.

Results: Among the 103 patients with an index diagnosis of BE-IND who were included in this study, 81 (78.6%) underwent a follow-up biopsy within 12 months of diagnosis; 10 (12.3%) had neoplasia, including four (4.9%) with advanced neoplasia. Among 79 patients without prevalent neoplasia who underwent more than 1 year of follow-up, 18 (22.8%) had developed neoplasia, including four (5.1%) with advanced neoplasia. AMACR and cyclin D1 expression levels were not correlated with prevalent or incident neoplasia; however, high p53 expression (>5%) was associated with prevalent advanced neoplasia on surveillance biopsy (P = 0.04) and with an increased risk of progression to advanced neoplasia (HR = 12; P = 0.03).

Conclusion: In this study, p53 expression was found to be predictive of prevalent advanced neoplasia and progression to advanced neoplasia in patients with BE-IND.

Systematic review and meta-analysis of immunohistochemical prognostic biomarkers in resected oesophageal adenocarcinoma

BACKGROUND

Oesophageal adenocarcinoma (OAC) is one of the fastest rising malignancies with continued poor prognosis. Many studies have proposed novel biomarkers but, to date, no immunohistochemical markers of survival after oesophageal resection have entered clinical practice. Here, we systematically review and meta-analyse the published literature, to identify potential biomarkers.

METHODS

Relevant articles were identified via Ovid medline 1946-2013. For inclusion, studies had to conform to REporting recommendations for tumor MARKer (REMARK) prognostic study criteria. The primary end-point was a pooled hazard ratio (HR) and variance, summarising the effect of marker expression on prognosis.

RESULTS

A total of 3059 articles were identified. After exclusion of irrelevant titles and abstracts, 214 articles were reviewed in full. Nine molecules had been examined in more than one study (CD3, CD8, COX-2, EGFR, HER2, Ki67, LgR5, p53 and VEGF) and were meta-analysed. Markers with largest survival effects were COX-2 (HR=2.47, confidence interval (CI)=1.15-3.79), CD3 (HR=0.51, 95% CI=0.32-0.70), CD8 (HR=0.55, CI=0.31-0.80) and EGFR (HR=1.65, 95% CI=1.14-2.16).

DISCUSSION

Current methods have not delivered clinically useful molecular prognostic biomarkers in OAC. We have highlighted the paucity of good-quality robust studies in this field. A genome-to-protein approach would be better suited for the development and subsequent validation of biomarkers. Large collaborative projects with standardised methodology will be required to generate clinically useful biomarkers.

BOB CAT: A Large-Scale Review and Delphi Consensus for Management of Barrett's Esophagus With No Dysplasia, Indefinite for, or Low-Grade Dysplasia

OBJECTIVES

Barrett's esophagus (BE) is a common premalignant lesion for which surveillance is recommended. This strategy is limited by considerable variations in clinical practice. We conducted an international, multidisciplinary, systematic search and evidence-based review of BE and provided consensus recommendations for clinical use in patients with nondysplastic, indefinite, and low-grade dysplasia (LGD).

METHODS

We defined the scope, proposed statements, and searched electronic databases, yielding 20,558 publications that were screened, selected online, and formed the evidence base. We used a Delphi consensus process, with an 80% agreement threshold, using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to categorize the quality of evidence and strength of recommendations.

RESULTS

In total, 80% of respondents agreed with 55 of 127 statements in the final voting rounds. Population endoscopic screening is not recommended and screening should target only very high-risk cases of males aged over 60 years with chronic uncontrolled reflux. A new international definition of BE was agreed upon. For any degree of dysplasia, at least two specialist gastrointestinal (GI) pathologists are required. Risk factors for cancer include male gender, length of BE, and central obesity. Endoscopic resection should be used for visible, nodular areas. Surveillance is not recommended for <5 years of life expectancy. Management strategies for indefinite dysplasia (IND) and LGD were identified, including a de-escalation strategy for lower-risk patients and escalation to intervention with follow-up for higher-risk patients.

CONCLUSIONS

In this uniquely large consensus process in gastroenterology, we made key clinical recommendations for the escalation/de-escalation of BE in clinical practice. We made strong recommendations for the prioritization of future research.

Progression of esophageal dysplasia to cancer

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the evolution of low-grade squamous and glandular dysplasia to invasive carcinoma; the mutational spectra of Barrett's esophagus and adenocarcinoma; the risk of p53-immunoreactive glandular dysplasia compared to non-immunoreactive mucosa for progression to cancer; the role of lectins in progression to adenocarcinoma; and the role of racemase immunoreactivity in the prediction of risk of adenocarcinoma.

Intestinal metaplasia of the sinonasal mucosa adjacent to intestinal-type adenocarcinoma. A morphologic, immunohistochemical, and molecular study

It has been hypothesized that the development of sinonasal intestinal-type adenocarcinoma (ITAC) occurs through intestinal metaplasia (IM) of the respiratory and/or glandular epithelium. The aim of this study was to characterize the histological, immunohistochemical, and molecular features of sinonasal IM. Histologic slides from 29 consecutive surgical specimens of ITAC were retrieved. Sections were stained for CDX2, cytokeratin 20 (CK20), MUC2, and p53. The status of TP53 gene exons 4-9 was assessed separately in areas of IM and in ITAC. Foci of IM were detected in eight cases (27.5%). They were all positive for CK20 and CDX2, while MUC2 was detected in six cases (75%). In six cases (75%), the metaplastic foci showed signs of dysplasia, including nuclear enlargement with increased nucleus to cytoplasm ratio, nuclear hyperchromasia, loss of nuclear polarity, and presence of prominent nucleoli. P53 nuclear immunoreactivity was observed in four cases. TP53 gene sequencing was successfully performed in six cases and revealed the same mutation in both IM and ITAC in two cases (c.832C > T and c.215G > C), while another ITAC showed a mutation that was not present in the adjacent IM (c.536A > G). In conclusion, our study suggests a possible clonal relationship between areas of sinonasal IM and ITAC, indicating that IM may represent a precursor lesion of ITAC. Improving the knowledge on the morphological and molecular features of IM is a key step to identify reliable biomarkers to determine the risk of sinonasal ITAC development.

Neoangiogenesis. Assessment in Esophageal Adenocarcinomas

Esophageal cancer has always been subject of research for various studies. According to some authors, esophageal cancer represents the 10th leading cause of cancer in the world with a 5-year survival of 10 %. In terms of anatomopathological form of the esophageal neoplasia, the literature mainly describes two major pathological types: adenocarcinoma and esophageal squamous cell carcinoma. Lately there has been an increased incidence of esophageal adenocarcinoma. The aim of the present work was to study neoangiogenesis in esophageal adenocarcinomas. The study was conducted on 40 cases diagnosed and surgically treated. Subsequently, fragment processing was performed using various immunohistochemical staining and marking with CD34 and p53 antigen. Later, quantitative measurements were performed, and images were taken using a microscope imaging system. In the end of the procedures, the professional program PRODIT 5.2. was applied. The study of the vascular system in the esophageal epithelial tumors revealed an axis consisting of three elements which have a mutual induction process: inflammatory infiltrate-neoangiogenesis-fibrosis, with significant differences between the three degrees of differentiation. A significant increase in tumor micro vascular density was present together with the increasing of the histological grading, with an inverse correlation with the degree of differentiation and directly proportional to the risk of malignancy.

Risk factors associated with Barrett’s epithelial dysplasia

AIM: To elucidate risk factors associated with dysplasia of short-segment Barrett’s esophagus (BE).

METHODS: A total of 151 BE patients who underwent endoscopic examination from 2004 to 2008 in Aoyama Hospital, Tokyo Women’s Medical University, Japan and whose diagnosis was confirmed from biopsy specimens were enrolled in the study. BE was diagnosed based on endoscopic findings of gastric-appearing mucosa or apparent columnar-lined esophagus proximal to the esophagogastric junction. Dysplasia was classified into three grades - mild, moderate and severe - according to the guidelines of the Vienna Classification System for gastrointestinal epithelial neoplasia. Anthropometric and biochemical data were analyzed to identify risk factors for BE dysplasia. The prevalence of Helicobacter pylori (H. pylori) infection and the expression of p53 by immunohistological staining were also investigated.

RESULTS: Histological examination classified patients into three types: specialized columnar epithelium (SCE) (n = 65); junctional (n = 38); and gastric fundic (n = 48). The incidence of dysplasia or adenocarcinoma from BE of the SCE type was significantly higher than that of the other two types (P < 0.01). The univariate analysis revealed that sex, H. pylori infection, body weight, p53 overexpression, and low diastolic blood pressure (BP) were associated with BE dysplasia. In contrast, body mass index, waist circumference, metabolic syndrome complications, and variables related to glucose or lipid metabolism were not associated with dysplasia. Multivariate logistic analysis showed that overexpression of p53 [odds ratio (OR) = 13.1, P = 0.004], H. pylori infection (OR = 0.19, P = 0.066), and diastolic BP (OR = 0.87, P = 0.021) were independent risk factors for epithelial dysplasia in BE patients with the SCE type.

CONCLUSION: Overexpression of p53 is a risk factor for dysplasia of BE, however, H. pylori infection and diastolic BP inversely associated with BE dysplasia might be protective.

Genomic DNA copy number alterations from precursor oral lesions to oral squamous cell carcinoma

Oral cancer is a multifactorial disease in which both environmental and genetic factors contribute to the aetiopathogenesis. Oral cancer is the sixth most common cancer worldwide with a higher incidence among Melanesian and South Asian countries. More than 90% of oral cancers are oral squamous cell carcinoma (OSCC). The present study aimed to determine common genomic copy number alterations (CNAs) and their frequency by including 12 studies that have been conducted on OSCCs using array comparative genomic hybridization (aCGH). In addition, we reviewed the literature dealing with CNAs that drive oral precursor lesions to the invasive tumors. Results showed a sequential accumulation of genetic changes from oral precursor lesions to invasive tumors. With the disease progression, accumulation of genetic changes increases in terms of frequency, type and size of the abnormalities, even on different regions of the same chromosome. Gains in 3q (36.5%), 5p (23%), 7p (21%), 8q (47%), 11q (45%), 20q (31%) and losses in 3p (37%), 8p (18%), 9p (10%) and 18q (11%) were the most common observations among those studies. However, losses are less frequent than gains but it appears that they might be the primary clonal events in causing oral cancer.

Mutation Spectra of Kras and Tp53 in Urethral and Lung Neoplasms in B6C3F1 Mice Treated with 3,3′,4,4′-Tetrachloroazobenzene

3,3′,4,4′-tetrachloroazobenzene (TCAB) is a contaminant formed during manufacture of various herbicide compounds. A recent National Toxicology Program study showed B6C3F1 mice exposed to TCAB developed a treatment-related increase in lung carcinomas in the high-dose group, and urethral carcinomas, an extremely rare lesion in rodents, in all dose groups. As the potential for environmental exposure to TCAB is widespread, and the mechanisms of urethral carcinogenesis are unknown, TCAB-induced urethral and pulmonary tumors were evaluated for alterations in critical human cancer genes, Kras and Tp53. Uroplakin III, CK20, and CK7 immunohistochemistry was performed to confirm the urothelial origin of urethral tumors. TCAB-induced urethral carcinomas harbored transforming point mutations in K-ras (38%) and Tp53 (63%), and 71% displayed nuclear TP53 expression, consistent with formation of mutant protein. Transition mutations accounted for 88% of Tp53 mutations in urethral carcinomas, suggesting that TCAB or its metabolites target guanine or cytosine bases and that these mutations are involved in urethral carcinogenesis. Pulmonary carcinomas in TCAB-exposed animals harbored similar rates of Tp53 (55%) and Kras (36%) mutations as urethral carcinomas, suggesting that TCAB may induce mutations at multiple sites by a common mechanism. In conclusion, TCAB is carcinogenic at multiple sites in male and female B6C3F1 mice through mechanisms involving Tp53 and Kras mutation.

The discrepancy between genetic polymorphism of p53 codon 72 and the expression of p53 protein in Helicobacter pylori-associated gastric cancer in Korea

The p53 gene has been referred to as 'the guardian of the genome' because it controls apoptosis and cell cycle arrest. The purpose of this study was to evaluate the association of p53 codon 72 genetic polymorphism and the p53 immunohistochemistry with Helicobacter pylori-associated gastroduodenal diseases, including gastric cancer. This study included 1,852 subjects: controls and patients with gastric cancer, dysplasia, benign gastric ulcers, and duodenal ulcers (DU). Biallelic polymorphism was genotyped by restriction fragment length polymorphism. Immunohistochemical analysis for the detection of mutant type p53 expression was performed. The frequency of the Pro/Pro allele of the p53 codon 72 was higher in the patients with H. pylori-positive dysplasia than in controls (OR: 2.3, 95% CI: 1.3-4.3), but it was less frequent among patients with a H. pylori-positive DU (OR: 0.5, 95% CI: 0.3-0.8). However, there was no significant association with gastric cancer, including the location, stage, or histological type of gastric cancer. Expression of a mutant type of p53 protein was detected in 6.3% of dysplastic tissues and 26.5% of cancerous tissues compared 0% in the controls. Positive expression was higher in the intestinal type of cancer (34.9%) than in the diffuse type (15.0%; P = 0.001). These results suggest that genetic polymorphism of p53 codon 72 played a role in the determination of H. pylori-associated gastroduodenal diseases, but p53 immunostaining did not correlate with those of the p53 genetic polymorphism analysis.

Aneuploidy and overexpression of Ki67 and p53 as markers for neoplastic progression in Barrett's esophagus: a case-control study

OBJECTIVES

Surveillance of patients with Barrett's esophagus (BE) aims at early detection and treatment of neoplastic changes, particularly esophageal adenocarcinoma (EAC). The histological evaluation of biopsy samples has its limitations, and biomarkers may improve early identification of BE patients at risk for progression to EAC. The aim of this study was to determine the predictive value of p53, Ki67, and aneuploidy as markers of neoplastic progression in BE.

METHODS

A total of 27 BE patients with histologically proven progression to high-grade dysplasia (HGD) or EAC (cases) and 27 BE patients without progression (controls) were selected and matched for age, gender, and duration of follow-up. Dysplasia grade was determined in 212 biopsy samples obtained during surveillance endoscopies from cases and in 231 biopsy samples collected from controls. DNA ploidy status was determined by flow cytometry, whereas Ki67 and p53 expression was determined by immunohistochemistry. Hazard ratios (HRs) were calculated by Cox regression adjusted for potentially confounding variables.

RESULTS

A univariate analysis showed that low-grade dysplasia (LGD) increased the risk of developing HGD/EAC compared with no dysplasia (HR 3.6; 95% confidence interval (CI): 1.6 - 8.1). Aneuploidy (HR 3.5; 95% CI: 1.3-9.4), strong Ki67 overexpression (HR 5.2; 95% CI: 1.5-17.6), and moderate p53 overexpression (HR 6.5; 95% CI: 2.5-17.1) were also associated with an increased risk of developing HGD/EAC, independent of the histological result. A multivariable analysis showed that in the presence of LGD, p53 overexpression, and to a lesser extent, Ki67 overexpression remained important risk factors for neoplastic progression, whereas aneuploidy was no longer predictive.

CONCLUSIONS

p53 overexpression and, to a lesser extent, Ki67 overexpression could predict neoplastic progression in BE irrespective of the histological result. These markers may be useful for identifying patients at an increased risk of developing EAC, either alone or used as a panel.

Immunohistochemical analysis of selected molecular markers in esophagus precancerous, adenocarcinoma and squamous cell carcinoma in Iranian subjects

BACKGROUND

The molecular and cellular mechanisms linking chronic inflammation and gastrointestinal malignancy are not known with certainty.

AIM

To investigate changes in potential causative factors during progression of esophagus cancer in a population living in high-risk area in Iran.

SUBJECTS

Formalin-fixed, paraffin-embedded esophageal specimens (n=87) from patients with gastroesophageal reflux disease (GERD), Barrett's metaplasia, adenocarcinoma (ADC) and squamous cells carcinoma (SCC) were collected based on their pathological diagnosis.

METHODS

Immunohistochemical (IHC) technique was used to study tissue accumulation of P53, P21, cyclooxygenase-2 (COX-2), glutathione S-transferase-P (GST-Pi) and nitrotyrosine (NT) in patients and controls.

RESULTS

P53 expression was not detected in esophageal tissues from normal and GERD samples, whereas it was found positive in Barrett's, ADC, and SCC samples. P21 positive sample was relatively higher in ADC patients as compared to that in SCC (ADC: 52.6%; SCC: 25%). GST-Pi expression was equally accumulated in all the samples. NT was predominantly expressed in ADC (72.7%). COX-2 expression was significantly higher in Barrett's (60.0%) and ADC (66.6%) as compared to that in GERD, SCC and normal. These data were further confirmed by detecting the scores of immunostainings in all the positive samples.

CONCLUSION

The pathological changes in ADC and SCC samples which were associated with increasing frequency of NT and COX-2 provides further evidence for involvement of these inflammatory factors in progression of esophagus cancer.

Increased p53 expression in the malignant transformation of Barrett's esophagus is accompanied by an upward shift of the proliferative compartment

Neoplastic progression in Barrett's esophagus (BE) occurs by a multistep process associated with early molecular and morphological changes. This study evaluated cell proliferation and p53 expression and their correlation in the development and progression of esophageal adenocarcinoma. PCNA and p53 expressions were analyzed in biopsy samples by immunohistochemistry including patients with reflux esophagitis, BE, BE with concomitant esophagitis, Barrett's dysplasia, esophageal adenocarcinoma and a control group without any histological changes. Progressive increase in cell proliferation and p53 expression was found in the sequence of malignant transformation of the esophageal mucosa. While cell proliferation was significantly lower in the control group compared with all other groups, there was no increase in p53 expression of esophageal tissues that were negative for dysplasia. Dysplastic BE tissues revealed significantly higher cell proliferation and p53 expression levels compared to BE, reflux esophagitis or BE with concomitant esophagitis. Both, cell proliferation and p53 expression were significantly higher in adenocarcinoma compared to BE or Barrett's dysplasia. Interestingly, while just BE with concomitant esophagitis showed significantly higher p53 expression levels than BE, both, BE with concomitant esophagitis and reflux esophagitis revealed significantly higher cell proliferation levels compared to BE. Alterations of cell proliferation and p53 expression showed a strong correlation. Simultaneous activation of cell proliferation and p53 expression strongly suggest their association with esophageal epithelial tumor genesis and particularly, their specific role in the biology of esophageal adenocarcinoma. Quantification of these parameters in BE is thought to be useful to identify patients at higher risk for progression to adenocarcinoma.

Loss of heterozygosities in Barrett esophagus, dysplasia, and adenocarcinoma detected by esophageal brushing cytology and gastroesophageal biopsy

BACKGROUND

Esophageal brushing cytology (EBC) and gastroesophageal biopsy (GEB) are complementary procedures for the evaluation of gastroesophageal lesions that help guide surveillance and treatment.

METHODS

The authors investigated loss of heterozygosity (LOH) of 17 microsatellite repeat markers near tumor suppressor genes in gastroesophageal lesions on 34 concomitant EBCs and GEBs.

RESULTS

The results indicated that there was progressive accumulation of LOHs toward malignant transformation. EBC samples a greater area than GEB, and more LOHs are detected by EBC than GEB. The combination of cytomorphology and detection of LOHs can improve diagnostic accuracy and is a more useful methodology with which to evaluate gastroesophageal lesions than either EBC or GEB alone. The authors also found that LOHs at 1p36, 9p21, and 17p13 may play an important role in Barrett esophagus (BE), LOHs at 10q23, 17p13, and 17q12 in low-grade dysplasia (LGD), LOHs at 5q23 and 17q21 in high-grade dysplasia (HGD), and LOHs at 5q23 and 21q22 in adenocarcinoma.

CONCLUSIONS

Detection of LOHs targeting tumor suppressor genes can be useful in evaluating gastroesophageal lesions, studying oncogenesis of gastroesophageal adenocarcinoma, and, in combination with EBC and GEB, determining surveillance for BE and LGD and/or treatment for HGD and adenocarcinoma.

p53 and Ki-67 in Barrett's carcinoma: is there any value to predict recurrence after circumferential endoscopic mucosal resection?

BACKGROUND

There are situations in which the specimens obtained after endoscopic mucosal resection of superficial adenocarcinoma arising from Barrett's esophagus are not adequate for histopathological assessment of the margins. In these cases, immunohistochemistry might be an useful tool for predicting cancer recurrence.

AIM

To evaluate the value of p53 and Ki-67 immunohistochemistry in predicting the cancer recurrence in patients with Barrett's esophagus-related cancer referred to circumferential endoscopic mucosal resection.

METHODS

Mucosectomy specimens from 41 patients were analyzed. All endoscopic biopsies prior to endoscopic mucosal resection presented high-grade dysplasia and cancer was detected in 23 of them. Positive reactions were considered the intense coloration in the nuclei of at least 90% of the cells in each high-power magnification field, and immunostaining could be classified as superficial or diffuse according to the mucosal distribution of the stained nuclei.

RESULTS

Endoscopic mucosal resection samples detected cancer in 21 cases. In these cases, p53 immunohistochemistry revealed a diffuse positivity for the great majority of these cancers (90.5% vs. 20%), and Ki-67 showed a diffuse pattern for all cases (100% vs. 30%); conversely, patients without cancer revealed a superficial or negative pattern for p53 (80% vs. 9.5%) and Ki-67 (70% vs. 0%). During a mean follow-up of 31.6 months, 5 (12.2%) patients developed six episodes of recurrent cancer. Endoscopic mucosal resection specimens did not show any significant difference in the p53 and Ki-67 expression for patients developing cancer after endoscopic treatment.

CONCLUSIONS

p53 and Ki-67 immunohistochemistry were useful to confirm the cancer; however, they had not value for predicting the recurrent carcinoma after circumferential endoscopic mucosal resection of Barrett's carcinoma.

Cigarette smoking, body mass index, gastro-esophageal reflux disease, and non-steroidal anti-inflammatory drug use and risk of subtypes of esophageal and gastric cancers by P53 overexpression

A number of risk factors for esophageal and gastric cancers have emerged, yet little is known whether risk factors map to molecular tumor markers such as overexpression of the tumor suppressor TP53. Using a US multicenter, population-based case-control study (170 cases of esophageal adenocarcinomas, 147 gastric cardia adenocarcinomas, 220 non-cardia gastric adenocarcinomas, and 112 esophageal squamous cell carcinomas), we examined whether the risk associated with cigarette smoking, body mass index (BMI), gastroesophageal reflux disease (GERD), and non-steroidal anti-inflammatory drug (NSAID) use varied by P53 overexpression. We defined P53 overexpression through immunohistochemistry of paraffin-embedded tumor tissues, using cutpoints based on percent of cells positive. Polytomous logistic regression was used to assess differences between each case group (defined by tumor subtype and P53 expression) and the control group by risk factors. The proportion of cases overexpressing P53 by tumor subtype was 72% for esophageal adenocarcinoma, 69% for gastric cardia adenocarcinoma, 52% for non-cardia gastric adenocarcinoma, and 67% for esophageal squamous cell carcinoma. For most tumor subtypes, we found little difference in risk factors by tumor P53 overexpression. For non-cardia gastric cancer however, an association with cigarette smoking was suggested for tumors that do not overexpress P53, whereas larger BMI was related to adenocarcinomas that overexpress P53 versus no overexpression. Overall, this study did not find a clear relationship between P53 protein overexpression and the known risk factors for subtypes of esophageal and gastric cancers. Further research on these tumors is needed to identify molecular markers associated with variations in the risk factor profiles.

Inducible nitric oxide synthase, nitrotyrosine and p53 mutations in the molecular pathogenesis of Barrett's esophagus and esophageal adenocarcinoma

Nitric oxide (NO) has been implicated as a potential causative factor for endogenous p53 mutations in gastrointestinal malignancy. To investigate the role of NO in esophageal adenocarcinoma (EADC), we studied patterns of p53 mutations, expression of inducible nitric oxide synthase (iNOS) and the tissue accumulation of nitrotyrosine (NTS), a stable reaction product of NO and a marker for cellular protein damage, in human premalignant and malignant esophageal epithelia. Tissues were obtained from patients with gastroesophageal reflux disease (GERD)-induced esophagitis (n = 76), Barrett's esophagus (BE; n = 119) and primary EADC (n = 54). DNA sequencing was used to characterize p53 mutations, RT-PCR to study iNOS mRNA expression, and immunohistochemistry to study NTS. Relative to self-matched normal epithelia, a progressive increase in iNOS mRNA expression was seen in GERD (30%; 23/76), BE (48%; 57/119), and EADC (63%; 34/54) tissues (P < 0.001). Among patients with EADC, elevated levels of NTS immunoreactivity were more frequent in tumors with p53 mutations (11/21; 52%) compared with tumors with wild-type p53 (9/33; 27%; P = 0.063), and specifically in tumors with p53 mutations at CpG dinucleotides (10/12; 83%) compared with non-CpG p53 mutations (1/9; 11%; P = 0.008). The increasing frequency of iNOS (mRNA) overexpression in GERD, BE and EADC supports the hypothesis that an active inflammatory process, most likely a consequence of GERD, underlies molecular progression to EADC. The highly significant association between NTS, reflecting chronic NO-induced cellular protein damage, and endogenous p53 mutations at CpG dinucleotides, provides further evidence for a molecular link between chronic inflammation and esophageal malignancy.

Prognostic value of cell adhesion in esophageal adenocarcinomas

Increased understanding of the molecular processes associated with the dysplasia-adenocarcinoma sequence linked to Barrett's esophagus may be beneficial for early tumor detection and refined diagnosis as well as for improved prognostication. We applied immunohistochemical staining for the markers Ki-67, p53, beta-catenin and E-cadherin in order to evaluate their prognostic importance in 59 Barrett's esophagus-associated adenocarcinomas. Reduced or absent membranous E-cadherin staining was identified in 75% of the tumors and predicted poor prognosis in manova (hazard ratio [HR] 3.3, P = 0.05). The small subset of tumors with low levels (< 10%) of Ki-67 staining showed a worse prognosis (HR 3.2, P < 0.01), whereas immunostaining for p53 and beta-catenin showed no correlation with prognosis. Deranged cell adhesion has been demonstrated to be an early event in tumor development. The down-regulation of E-cadherin and its prognostic importance indicate that cell adhesion may be a prime area for targeted therapies in esophageal adenocarcinoma.

Field defects in progression to gastrointestinal tract cancers

A field of defective tissue may represent a pre-malignant stage in progression to many cancers. However, field defects are often overlooked in studies of cancer progression through assuming tissue at some distance from the cancer is normal. We indicate, however, the generality of field defects in gastrointestinal cancers, including cancers of the oropharynx, esophagus, stomach, bile duct, pancreas, small intestine and colon/rectum. Common features of these field defects are reduced apoptosis competence, aberrant proliferation and genomic instability. These features are often associated with high bile acid exposure and may explain the association of dietary-related factors with cancer progression.

High-grade dysplasia in Barrett's esophagus is associated with increased expression of calgranulin A and B

OBJECTIVE

Patients with Barrett's esophagus (BE) are at risk of developing esophageal adenocarcinoma, which is usually preceded by dysplastic changes of the metaplastic mucosa. The aim of this study was to increase the understanding of the development of dysplastic lesions in BE through the identification of genes that are differentially transcribed in these tissue types.

MATERIAL AND METHODS

Paired biopsy samples from non-dysplastic BE, and high-grade dysplasia from a single patient were used for histological evaluation and gene expression profile analysis. In addition, relative mRNA levels of differentially expressed genes were tested to validate the association with the presence or absence of dysplasia by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) (58 biopsy samples containing squamous epithelium, non-dysplastic BE, high-grade dysplasia, or adenocarcinoma from 23 unrelated patients) and immunohistochemistry (9 sets of paired non-dysplastic/high-grade dysplasiac samples from 9 unrelated patients).

RESULTS

Microarray results from high-grade dysplasia showed 866 genes with a>2-fold difference in mRNA levels compared with non-dysplastic BE. Subsequent comparison of mRNA levels of the 22 genes with a>10-fold difference in 76 unrelated biopsies showed that only two of these genes, i.e. calgranulin A (S100A8; p=0.017) and calgranulin B (S100A9; p=0.022), were consistently up-regulated in high-grade dysplasia, as were protein levels for calgranulin A and B.

CONCLUSIONS

This is the first report of an association between the calprotectin complex, which is involved in chemotaxis of neutrophils, and the progression towards high-grade dysplasia in BE. It remains to be established whether differentially expressed proteins in biopsies form BE can be used to facilitate the diagnosis of advanced dysplasia in BE.

Aurora-A overexpression as an early marker of reflux-related columnar mucosa and Barrett’s oesophagus

BACKGROUND

The development of oesophageal adenocarcinoma is generally closely associated with the presence of a specialised intestinal-type epithelium such as that found in Barrett's oesophagus (BO). A particular histological condition is when the distal oesophagus showing cardiac and/or fundic mucosa without intestinal metaplasia cannot be defined as 'Barrett's mucosa' [condition that we call 'columnar-lined oesophagus' (CLO)] and up till now, there has been no agreement in literature about the management of this condition. Aurora-A overexpression leads to centrosome amplification, chromosomal instability and aneuploidy in mammalian cells.

PATIENTS AND METHODS

A prospective study was carried out on 28 consecutive patients who presented columnar mucosa above the gastro-oesophageal junction (GOJ) at endoscopy. As controls, two more biopsies were obtained, one on the normal-appearing squamous oesophagus above the GOJ, as far as possible from the columnar mucosa (controls A), and one taken 1 cm below the GOJ (controls B). The Aurora-A and p53 expression levels were analysed respectively by Quantitative Real Time PCR and immunohistochemistry.

RESULTS

Twelve patients were affected by BO (43%) while the other 16 patients (57%) had a CLO. Nine of 28 (32%) cases were focally positive for p53 immunostaining. All the BO/CLO samples were positive for the Aurora-A transcript with regard to controls. Furthermore, 13 of 28 (46%) cases showed overexpression (above the median for the whole group).

CONCLUSION

Due to the low number of cases, we are not at present able to state that statistically significant quantitative differences in Aurora-A messenger RNA expression exist between CLO and BO cases with and without dysplasia and p53-positive immunostaining. Further studies on a larger number of cases with a follow-up period are necessary in order to establish the risk of progression and the correct management of these subjects.

Targeting the Wnt signaling pathway to treat Barrett’s esophagus

Barrett's esophagus (BE) is an acquired condition in which the normal squamous epithelium in the distal esophagus is replaced by a metaplastic columnar epithelium, as a complication of chronic gastroesophageal reflux. The clinical significance of this disease is its associated predisposition to esophageal adenocarcinoma (EAC). Recently, and similarly to other human malignancies, the Wnt signaling pathway and its key component beta-catenin have been implicated in the carcinogenesis of BE. Although mutations in adenomatous polyposis coli (APC) or beta-catenin are rare in EAC, alterations of upstream components, such as overexpression of Wnt2 ligand or downregulation of Wnt antagonists may play dominant roles in the activation of the Wnt pathway. Increasing evidence suggests that inhibiting the Wnt pathway may be a new targeted therapy for the treatment of cancers and could, therefore, be promising for the cure of EAC, which remains a highly lethal disease.