Derivation of genetic biomarkers for cancer risk stratification in Barrett's oesophagus: a prospective cohort study.

OBJECTIVE: The risk of developing adenocarcinoma in non-dysplastic Barrett's oesophagus is low and difficult to predict. Accurate tools for risk stratification are needed to increase the efficiency of surveillance. We aimed to develop a prediction model for progression using clinical variables and genetic markers. METHODS: In a prospective cohort of patients with non-dysplastic Barrett's oesophagus, we evaluated six molecular markers: p16, p53, Her-2/neu, 20q, MYC and aneusomy by DNA fluorescence in situ hybridisation on brush cytology specimens. Primary study outcomes were the development of high-grade dysplasia or oesophageal adenocarcinoma. The most predictive clinical variables and markers were determined using Cox proportional-hazards models, receiver operating characteristic curves and a leave-one-out analysis. RESULTS: A total of 428 patients participated (345 men; median age 60 years) with a cumulative follow-up of 2019 patient-years (median 45 months per patient). Of these patients, 22 progressed; nine developed high-grade dysplasia and 13 oesophageal adenocarcinoma. The clinical variables, age and circumferential Barrett's length, and the markers, p16 loss, MYC gain and aneusomy, were significantly associated with progression on univariate analysis. We defined an 'Abnormal Marker Count' that counted abnormalities in p16, MYC and aneusomy, which significantly improved risk prediction beyond using just age and Barrett's length. In multivariate analysis, these three factors identified a high-risk group with an 8.7-fold (95% CI 2.6 to 29.8) increased HR when compared with the low-risk group, with an area under the curve of 0.76 (95% CI 0.66 to 0.86). CONCLUSIONS: A prediction model based on age, Barrett's length and the markers p16, MYC and aneusomy determines progression risk in non-dysplastic Barrett's oesophagus.

Aberrant TP53 detected by combining immunohistochemistry and DNA-FISH improves Barrett's esophagus progression prediction: a prospective follow-up study.

Barrett's esophagus (BE) goes through a sequence of low grade dysplasia (LGD) and high grade dysplasia (HGD) to esophageal adenocarcinoma (EAC). The current gold standard for BE outcome prediction, histopathological staging, can be unreliable. TP53 abnormalities may serve as prognostic biomarkers. TP53 protein accumulation detected by immunohistochemistry (IHC) indirectly assesses TP53 mutations. DNA fluorescent in situ hybridization (FISH) on brush cytology specimens directly evaluates gene locus loss. We evaluated if IHC and FISH are complementary tools to assess TP53 abnormalities and tested their prognostic value in a long-term prospective follow-up of a BE cohort. TP53 IHC on tissue sections and FISH on brush cytology specimens were evaluated for 116 BE patients with respect to the different histological stages. The TP53 abnormalities were further studied in a panel of cell lines representative of the Barrett's carcinogenic sequence. For 91patients, the predictive value of TP53 abnormalities with respect to progression to HGD/EAC was tested after long term follow-up. The frequency of IHC and FISH TP53 abnormalities increased significantly with increasing histological stage (P < 0.001, Chi(2) -test). Combining the techniques detected TP53 abnormalities in 100% of patients with LGD, HGD, and EAC. Multivariate analysis showed that IHC (hazard ratio: 17, 95% CI: 3.2-96, P = 0.001) and FISH (hazard ratio: 7.3, 95% CI: 1.3-41, P = 0.02) were both independent significant predictors of progression. Combining FISH and IHC in assessing TP53 abnormalities leads to an increased detection rate of TP53 aberrations and improved accuracy for predicting BE progression.

Prediction of response to endoscopic therapy of Barrett's dysplasia by using genetic biomarkers.

BACKGROUND: Endoscopic therapy for the treatment of high-grade dysplasia (HGD) and intramucosal cancer (IMC) in Barrett's esophagus (BE) may not always result in complete remission of dysplasia (CRD). OBJECTIVE: To determine whether genetic alterations in the Barrett's mucosa can predict response to endoscopic therapy. DESIGN: Retrospective cohort study. SETTING: Tertiary-care institution. PATIENTS: Selected patients who underwent endoscopic therapy for BE containing HGD/IMC between 2003 and 2010. INTERVENTIONS: Endoscopic therapy combining mucosal resection and different ablation modalities was performed based on patient characteristics, endoscopic findings, and technique evolution. Fluorescence in situ hybridization was used to evaluate genetic alterations on baseline endoscopic cytology brushings by using probes directed to loci 8q24 (MYC), 9p21 (CDKN2A; alias P16), 17q12 (ERBB2; alias Her-2/neu), and 20q13.2 (ZNF217). MAIN OUTCOME MEASUREMENTS: Genetic biomarkers predicting achievement of CRD after endoscopic therapy. RESULTS: A total of 181 patients were included (145 men; 66 ± 10 years of age). There were 130 patients (72%) who responded to endoscopic therapy with CRD. Multiple gains detected by fluorescence in situ hybridization was found to be a negative predictor (hazard ratio 0.57; 95% confidence interval, 0.40-0.82) after adjusting for potential clinical confounders. Similar results were found when analyses were restricted to patients (n = 66) undergoing radiofrequency ablation (hazard ratio 0.58; 95% confidence interval, 0.31-1.09). LIMITATIONS: Retrospective study, heterogeneity of treatment modalities. CONCLUSION: Patients with multiple gains detected by brush cytology specimens may have a lower response rate to endoscopic therapy. The presence of multiple gains can be an adjunct to standard histology in prognosticating BE patients with HGD/IMC undergoing endoscopic therapy.

Genetic Abnormalities in Biliary Brush Samples for Distinguishing Cholangiocarcinoma from Benign Strictures in Primary Sclerosing Cholangitis.

Background. Primary sclerosing cholangitis (PSC) is a chronic inflammatory liver disease and is strongly associated with cholangiocarcinoma (CCA). The lack of efficient diagnostic methods for CCA is a major problem. Testing for genetic abnormalities may increase the diagnostic value of cytology. Methods. We assessed genetic abnormalities for CDKN2A, TP53, ERBB2, 20q, MYC, and chromosomes 7 and 17 and measures of genetic clonal diversity in brush samples from 29 PSC patients with benign biliary strictures and 12 patients with sporadic CCA or PSC-associated CCA. Diagnostic performance of cytology alone and in combination with genetic markers was evaluated by sensitivity, specificity, and area under the curve analysis. Results. The presence of MYC gain and CDKN2A loss as well as a higher clonal diversity was significantly associated with malignancy. MYC gain increased the sensitivity of cytology from 50% to 83%. However, the specificity decreased from 97% to 76%. The diagnostic accuracy of the best performing measures of clonal diversity was similar to the combination of cytology and MYC. Adding CDKN2A loss to the panel had no additional benefit. Conclusion. Evaluation of MYC abnormalities and measures of clonal diversity in brush cytology specimens may be of clinical value in distinguishing CCA from benign biliary strictures in PSC.

Dynamic clonal equilibrium and predetermined cancer risk in Barrett's oesophagus.

Surveillance of Barrett's oesophagus allows us to study the evolutionary dynamics of a human neoplasm over time. Here we use multicolour fluorescence in situ hybridization on brush cytology specimens, from two time points with a median interval of 37 months in 195 non-dysplastic Barrett's patients, and a third time point in a subset of 90 patients at a median interval of 36 months, to study clonal evolution at single-cell resolution. Baseline genetic diversity predicts progression and remains in a stable dynamic equilibrium over time. Clonal expansions are rare, being detected once every 36.8 patient years, and growing at an average rate of 1.58 cm(2) (95% CI: 0.09-4.06) per year, often involving the p16 locus. This suggests a lack of strong clonal selection in Barrett's and that the malignant potential of 'benign' Barrett's lesions is predetermined, with important implications for surveillance programs.

Recalcitrant plantar warts during azathioprine therapy for Crohn's disease.

Dermatological complications of long-term immunosuppressive therapy in inflammatory bowel disease (IBD) are rarely reported. We present the case of a 29-year-old man with worsening of plantar warts while on azathioprine therapy for Crohn's disease. This case underlines the need to perform thorough skin examination of IBD patients before and during immunosuppressive therapy.

Genetic and epigenetic abnormalities in primary sclerosing cholangitis-associated cholangiocarcinoma.

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease of unknown etiology, characterized by chronic inflammation of the biliary tree with subsequent fibrosis and cirrhosis of the liver. Patients with PSC are at increased risk for the development of cholangiocarcinoma (CCA), a highly malignant epithelial tumor arising from the intrahepatic and extrahepatic bile ducts. Currently, orthotopic liver transplantation is the only curative treatment. The lack of efficient diagnostic methods for early detection and the limited therapeutic options for CCA are major problems and are associated with poor survival. The pathogenesis of PSC-associated CCA is complex and poorly understood. It seems that pro-inflammatory cytokines play an important role in genetic and epigenetic changes that contribute to the carcinogenic process. The mapping of genetic alterations may elucidate molecular targets that may be applied as biomarkers to facilitate early diagnosis of malignant degeneration to improve patient outcome. In the last decade, the introduction of several novel molecular techniques available for genome-wide screening has advanced our knowledge on many of the genetic abnormalities that are prevalent in CCA and PSC-associated CCA. This review summarizes genetic and epigenetic abnormalities, which have important potential for clinical application.