[Show abstract][Hide abstract] ABSTRACT: Background
Mipomersen is an antisense oligonucleotide that inhibits apolipoprotein (apo) B synthesis and lowers plasma low density lipoprotein (LDL) cholesterol even in the absence of LDL receptor function, presumably due to the inhibition of hepatic production of triglyceride-rich very low density lipoprotein (VLDL) particles. By virtue of this mechanism, mipomersen therapy commonly results in the development of hepatic steatosis. Because this is frequently accompanied by alanine aminotransferase (ALT) elevations, concern has arisen that mipomersen could promote the development of steatohepatitis, which could in turn lead to fibrosis and cirrhosis over time.
The objective of this study was to assess the liver biopsy findings in patients treated with mipomersen.
We describe 7 patients who underwent liver biopsy during the mipomersen clinical development programs. Liver biopsies were reviewed by a single, blinded pathologist.
The histopathological features were characterized by simple steatosis, without significant inflammation or fibrosis.
These findings suggest that hepatic steatosis due to mipomersen is distinct from non-alcoholic steatohepatitis.
Journal of Clinical Lipidology 08/2014; · 3.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Endoscopic ampullectomy is increasingly performed in patients with familial adenomatous polyposis (FAP)-associated ampullary adenomas. We sought to define the procedure-associated morbidities and long-term outcomes.
We performed a retrospective chart review of patients with FAP who underwent endoscopic ampullectomy at two tertiary institutions between 1999 and 2010. The severity of duodenal polyposis was classified according to Spigelman's classification.
Of 26 FAP patients who underwent endoscopic ampullectomy, 21 arose in the setting of Spigelman's stage II duodenal polyposis. Adverse events associated with endoscopic ampullectomy included acute pancreatitis (19.2 %), abdominal pain (7.6 %), and bleeding (3.8 %). The mean resected adenoma size was 0.99 ± 0.34 cm. Three adenomas (12.0 %) contained foci of high-grade dysplasia. Follow-up data were available for 24 patients. The mean follow-up duration was 84.5 ± 36.2 months. Adenoma recurrence was observed in 14 patients (58.3 %; 14/24) at a mean of 38.3 months after initial ampullectomy. Adenomas ≥10 mm recurred more frequently than smaller adenomas (76.9 vs. 36.4 %; p = 0.002). Positive margins were not associated with higher recurrence rates. No cancers were observed during long-term follow-up. Three patients underwent a Whipple procedure, but none was performed for a recurrent ampullary adenoma.
Endoscopic ampullectomy in FAP can be performed safely. Because ampullary adenomas frequently recur after endoscopic ampullectomy, close surveillance is essential. Smaller tumors are less likely to recur, suggesting a benefit for early recognition of these lesions.
[Show abstract][Hide abstract] ABSTRACT: Most patients with familial adenomatous polyposis (FAP) develop gastric fundic gland polyps, with many displaying low grade dysplasia. This study evaluates the natural history and morphologic phenotype of dysplasia in FAP associated fundic gland polyps.
Patients with FAP and dysplastic fundic gland polyps (n=24) were identified. 22 of 24 FAP associated dysplastic fundic gland polyps showed a gastric phenotype and two had mixed phenotype. Over a mean 6.1 year follow up (range 0.8-12.6 years) and 5.7 endoscopies (range 2-22), one patient (4%) was diagnosed with a fundic gland polyp with high grade dysplasia, while 23 patients (96%) in this cohort had either no dysplasia or persistent low grade dysplasia. Contemporary patients with sporadic fundic gland polyps with low grade dyplasia had similar morphology and outcomes to the FAP associated fundic gland polyp cohort. Dysplasia in fundic gland polyps (FAP associated and sporadic) was less frequently associated with intestinal phenotype, high grade dysplasia, and the finding of concurrent or subsequent carcinoma compared to contemporary patients with sporadic gastric dysplasia not occurring in fundic gland polyps.
This cohort of patients with FAP associated dysplastic fundic gland polyps rarely developed high grade dysplasia and gastric adenocarcinoma was absent. This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this survey was to ascertain reporting habits of pathologists towards sessile serrated adenomas/polyps (SSA/P).
A questionnaire designed to highlight diagnostic criteria, approach and clinical implications of SSA/P was circulated electronically to 45 pathologists in the UK and North America.
Forty-three of 45 pathologists agreed to participate. The vast majority (88%) had a special interest in gastrointestinal (GI) pathology, had great exposure to GI polyps in general with 40% diagnosing SSA/P at least once a week if not more, abnormal architecture was thought by all participants to be histologically diagnostic, and 11% would make the diagnosis if a single diagnostic histological feature was present in one crypt only, while a further 19% would diagnose SSA/P in one crypt if more than one diagnostic feature was present. The vast majority agreed that deeper sections were useful and 88% did not feel proliferation markers were useful. More than one-third did not know whether, or did not feel that, their clinicians were aware of the implications of SSA/P.
98% of pathologists surveyed are aware that SSA/P is a precursor lesion to colorectal cancer, the majority agree on diagnostic criteria, and a significant number feel that there needs to be greater communication and awareness among pathologists and gastroenterologists about SSA/P.
Journal of clinical pathology 01/2014; · 2.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cancers arising in mucosal tissues account for a disproportionately large fraction of malignancies. Immunoglobulin G (IgG) and the neonatal Fc receptor for IgG (FcRn) have an important function in the mucosal immune system that we have now shown extends to the induction of CD8(+) T cell-mediated antitumor immunity. We demonstrate that FcRn within dendritic cells (DCs) was critical for homeostatic activation of mucosal CD8(+) T cells that drove protection against the development of colorectal cancers and lung metastases. FcRn-mediated tumor protection was driven by DCs activation of endogenous tumor-reactive CD8(+) T cells via the cross-presentation of IgG complexed antigens (IgG IC), as well as the induction of cytotoxicity-promoting cytokine secretion, particularly interleukin-12, both of which were independently triggered by the FcRn-IgG IC interaction in murine and human DCs. FcRn thus has a primary role within mucosal tissues in activating local immune responses that are critical for priming efficient anti-tumor immunosurveillance.
[Show abstract][Hide abstract] ABSTRACT: All cancers are believed to arise by dynamic, stochastic somatic genomic evolution with genome instability, generation of diversity and selection of genomic alterations that underlie multi-stage progression to cancer. Advanced esophageal adenocarcinomas (EAs) have high levels of somatic copy number alterations. Barrett's esophagus (BE) is a risk factor for developing EA, and somatic chromosomal alterations (SCAs) are known to occur in BE. The vast majority (~95%) of individuals with BE do not progress to EA during their lifetimes, but a small subset develop EA, many of which arise rapidly even in carefully monitored patients without visible endoscopic abnormalities at the index endoscopy. Using a well-designed, longitudinal case-cohort study, we characterized SCA as assessed by SNP arrays over space and time in 79 "progressors" with BE as they approach the diagnosis of cancer and 169 "nonprogressors" with BE who did not progress to EA over 20,425 person-months of follow-up. The genomes of nonprogressors typically had small localized deletions involving fragile sites and 9p loss/copy neutral LOH that generate little genetic diversity and remained relatively stable over prolonged follow-up. As progressors approach the diagnosis of cancer, their genomes developed chromosome instability with initial gains and losses, genomic diversity, and selection of SCAs followed by catastrophic genome doublings. Our results support a model of differential disease dynamics in which nonprogressor genomes largely remain stable over prolonged periods whereas progressor genomes evolve significantly increased SCA and diversity within four years of EA diagnosis, suggesting a window of opportunity for early detection.
Cancer Prevention Research 11/2013; · 4.89 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epithelial dysplasia is an important histologic diagnosis, signifying the presence of pre-invasive disease, usually needing intervention. However, the specific genetic changes responsible for the induction of this phenotypic change are unknown. Moreover, recent reports indicate that the dysplastic phenotype may not be immutable: in basal crypt dysplasia (CD), unequivocal dysplastic changes are seen in the crypts in Barrett's oesophagus and other pre-invasive lesions in the gastrointestinal tract, but the upper crypts and surface epithelium associated with these dysplastic crypts show the definitive morphology of a differentiated epithelium. The genotypic relationship between CD and the differentiated surface epithelium is presently unclear. We obtained 17 examples of CD: the lower crypts and upper crypts and surface epithelium were differentially laser-microdissected from formalin-fixed, paraffin embedded sections and mutations were sought in tumour suppressor genes frequently associated with progression in Barrett's oesophagus. We found two patients who both showed a c. C238T mutation in the CDKN2A (CDKN2AInk4A) gene and where the precise microanatomical relationships could be discerned: this mutation was present in both the CD at the crypt base and in the upper crypt and surface epithelium. We conclude that, in CD, the dysplastic basal crypt epithelium and the upper crypt and surface epithelium show clonal CDKN2A mutations, thus showing definitively that the surface epithelium is derived from the dysplastic crypt epithelium: the dysplastic phenotype is therefore not fixed and can be reversed. The mechanism of this change is unclear but may be related to the possibility that dysplastic cells can, probably early in their progression, respond to differentiation signals. However, it is also clear that a heavy mutational burden can be borne by crypts in the gastrointestinal tract without the development of phenotypic dysplasia. We are evidently some way from understanding the plasticity and the genotypic correlates of the dysplastic phenotype.
The Journal of Pathology 05/2013; · 7.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND:: The purpose of this study was to reevaluate the clinical and pathologic features and outcomes in patients with Crohn's disease with an adenoma-like dysplasia-associated lesion or mass (DALMs) to determine if polypectomy is adequate treatment. METHODS:: The clinical, endoscopic and pathologic features, and outcomes of 50 patients with Crohn's disease, each with ≥1 adenoma-like DALM were evaluated. The median length of follow-up was 39 months (range: 0.5-156 months). RESULTS:: Of the 50 patients with Crohn's disease (male to female ratio, 30:20; median age: 53 years; median duration of disease: 83 months), 11 had ileal disease, 26 had colonic disease, and 13 had both ileal and colonic disease. Approximately 43% of polyps occurred within areas of previous or concurrent colitis, whereas 57% occurred in areas not previously involved by colitis. Most polyps had tubular architecture and contained low-grade dysplasia. Of the patients who had polypectomy followed by surveillance, 45% developed new adenoma-like DALMs, but none developed flat dysplasia and only 1 had adenocarcinoma at the time of resection, which was within 3 months of polypectomy. There were no differences in the clinical or pathologic features or outcomes in patients who had adenoma-like DALMs within versus outside areas of previous or concurrent colitis, except that the former showed a higher risk of developing new polyps within areas of colitis and near the site of the original polyp compared with the latter. CONCLUSIONS:: Patients with Crohn's disease who develop an adenoma-like DALM, regardless of its location in relationship to previous or concurrent colitis, may be treated safely with polypectomy and continued surveillance.
[Show abstract][Hide abstract] ABSTRACT: The histological definition of Barrett's esophagus (BE) is debated, particularly regarding the phenotype of its metaplastic columnar epithelium. Histologically proven intestinal metaplasia (IM) was the sine qua non condition for a diagnosis of BE but, more recently, non-intestinalized (i.e., cardiac gastric-type; GM) columnar metaplasia has been re-included in the spectrum of Barrett's histology. MicroRNAs modulate cell commitment, and are also reportedly dysregulated in Barrett's carcinogenesis. This study investigates miRNA expression in the histological spectrum of esophageal columnar metaplastic changes, specifically addressing the biological profile of GM vs. IM.
A study was performed to discover microRNA microarray in 30 matching mucosa samples obtained from 10 consecutive BE patients; for each patient, biopsy tissue samples were obtained from squamous, GM and intestinalized epithelium. Microarray findings were further validated by qRT-PCR analysis in another bioptic series of 75 mucosa samples.
MicroRNA profiling consistently disclosed metaplasia-specific microRNA signatures. Six microRNAs were significantly dysregulated across the histological phenotypes considered; five of them (two overexpressed (hsa-miR-192; -miR-215) and three under-expressed (hsa-miR-18a*; -miR-203, and -miR-205)) were progressively dysregulated in the phenotypic sequence from squamous to gastric-type, to intestinal-type mucosa samples.
A consistent microRNA expression signature underlies both gastric- and intestinal-type esophageal metaplasia. The pattern of microRNA dysregulation suggests that GM may further progress to IM. The clinico-pathological implications of these molecular profiles prompt further study on the "personalized" cancer risk associated with each of these metaplastic transformations.
Clinical and translational gastroenterology. 01/2013; 4:e34.
[Show abstract][Hide abstract] ABSTRACT: Serrated lesions of the colorectum are the precursors of perhaps one-third of colorectal cancers (CRCs). Cancers arising in serrated lesions are usually in the proximal colon, and account for a disproportionate fraction of cancer identified after colonoscopy. We sought to provide guidance for the clinical management of serrated colorectal lesions based on current evidence and expert opinion regarding definitions, classification, and significance of serrated lesions. A consensus conference was held over 2 days reviewing the topic of serrated lesions from the perspectives of histology, molecular biology, epidemiology, clinical aspects, and serrated polyposis. Serrated lesions should be classified pathologically according to the World Health Organization criteria as hyperplastic polyp, sessile serrated adenoma/polyp (SSA/P) with or without cytological dysplasia, or traditional serrated adenoma (TSA). SSA/P and TSA are premalignant lesions, but SSA/P is the principal serrated precursor of CRCs. Serrated lesions have a distinct endoscopic appearance, and several lines of evidence suggest that on average they are more difficult to detect than conventional adenomatous polyps. Effective colonoscopy requires an endoscopist trained in the endoscopic appearance of serrated lesions. We recommend that all serrated lesions proximal to the sigmoid colon and all serrated lesions in the rectosigmoid >5 mm in size, be completely removed. Recommendations are made for post-polypectomy surveillance of serrated lesions and for surveillance of serrated polyposis patients and their relatives.
The American Journal of Gastroenterology 06/2012; 107(9):1315-29. · 9.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Esophageal adenocarcinoma (EA) is increasingly common among patients with Barrett's esophagus (BE). We aimed to provide consensus recommendations based on the medical literature that clinicians could use to manage patients with BE and low-grade dysplasia, high-grade dysplasia (HGD), or early-stage EA.
We performed an international, multidisciplinary, systematic, evidence-based review of different management strategies for patients with BE and dysplasia or early-stage EA. We used a Delphi process to develop consensus statements. The results of literature searches were screened using a unique, interactive, Web-based data-sifting platform; we used 11,904 papers to inform the choice of statements selected. An a priori threshold of 80% agreement was used to establish consensus for each statement.
Eighty-one of the 91 statements achieved consensus despite generally low quality of evidence, including 8 clinical statements: (1) specimens from endoscopic resection are better than biopsies for staging lesions, (2) it is important to carefully map the size of the dysplastic areas, (3) patients that receive ablative or surgical therapy require endoscopic follow-up, (4) high-resolution endoscopy is necessary for accurate diagnosis, (5) endoscopic therapy for HGD is preferred to surveillance, (6) endoscopic therapy for HGD is preferred to surgery, (7) the combination of endoscopic resection and radiofrequency ablation is the most effective therapy, and (8) after endoscopic removal of lesions from patients with HGD, all areas of BE should be ablated.
We developed a data-sifting platform and used the Delphi process to create evidence-based consensus statements for the management of patients with BE and early-stage EA. This approach identified important clinical features of the diseases and areas for future studies.
[Show abstract][Hide abstract] ABSTRACT: Abundant recent data suggest that sessile serrated adenoma/polyp (SSA/P) is an early precursor lesion in the serrated pathway of carcinogenesis. It is believed that SSA/Ps develop cancer by an SSA/P-dysplasia-carcinoma sequence. Hyperplastic polyps (HPs) share some histologic and molecular characteristics with SSA/P, but it is unclear whether SSA/Ps are derived from HPs or whether they develop by a different pathogenetic pathway. Previous studies have shown that serrated polyps from Korean patients show different prevalence rates of certain molecular abnormalities compared with similar lesions from American patients, and this suggests that lifestyle and dietary factors may influence the serrated neoplasia pathway. The purpose of this study was to evaluate the molecular features of HPs and SSA/Ps, the latter both with and without dysplasia, from Korean patients and to compare the findings with similar lesions from American patients. One hundred and eleven serrated polyps, consisting of 45 HPs (30 microvesicular, 11 goblet cell, 4 mucin depleted) and 56 SSA/Ps (36 with dysplasia, 20 without dysplasia), were retrieved from the pathology files of a large medical center in Korea and 38 SSA/P from American patients were evaluated for BRAF and KRAS mutations, microsatellite instability, and hypermethylation of O6-methylguanine-DNA methyltransferase (MGMT), hMLH1, adenomatous polyposis coli (APC), p16, methylated in tumor-1 (MINT-1), MINT2, and MINT31. Methylation of hMLH1 was performed using 2 different sets of primers. Twenty-three conventional adenomas from Korean patients were included as controls. The data were compared between polyp subtypes and between polyps in the right versus the left colon. With regard to HP, KRAS mutations were present in 31.1% of polyps and BRAF mutations in 46.7% of polyps. KRAS mutations were significantly more common in goblet cell HP and BRAF in microvesicular HP (MVHP). Methylation of MGMT, hMLH1, APC, p16, MINT1, MINT2, and MINT31 were present in 42.2%, 64.4% (and 24.4%), 37.8%, 60%, 68.9%, 51.1%, and 60% of HPs. CpG island methylator phenotype high was noted in 60% of HPs. Methylation of hMLH1, p16, MINT2, and MINT31 were more frequent in MVHPs compared with other types of HPs. In contrast, SSA/Ps showed KRAS and BRAF mutations in 12.5% and 60.7% of cases, respectively. Methylation of all tumor-related genes, except hMLH1 (23.2% using 1 type of primers) and APC (37.5%), occurred in >50% of lesions, and CpG island methylator phenotype (CIMP) high was noted in 76.8% of cases. None of the molecular findings were significantly more common in SSA/P with, versus those without, dysplasia, but only 2 of the 36 polyps with dysplasia were of the conventional adenomatous type; the remainder (34 of 36) was of the serrated type. Nevertheless, both SSA/P with conventional adenomatous dysplasia showed methylation of MGMT, APC, MINT1, and MINT31 and were CIMP high. BRAF mutations, methylation of most tumor related genes, and CIMP high occurred more frequently in HPs and SSA/Ps in the right colon, compared with the left colon. In fact, no significant differences were observed between HPs and SSPs of the right colon and HPs and SSA/Ps from the left colon. Furthermore, compared with American patients, Korean male individuals were affected more frequently than female individuals, and both BRAF mutations and hMLH1 methylation were less frequent in the latter compared with the former. We conclude that HPs and SSA/Ps in Korean patients share some, but not all, clinical and molecular characteristics to those that occur in Americans. The data support the theory that the right and left colon are biologically different with regard to susceptibility to serrated cancer, and that anatomic location (right vs. left) may be a more significant risk factor of progression than the histologic type of polyp. Our data also support the theory that right-sided MVHPs may be a precursor to SSA/P.
The American journal of surgical pathology 09/2011; 35(9):1274-86. · 4.06 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Endoscopic ablation of Barrett's esophagus can bury metaplastic glands under a layer of neosquamous epithelium. To explore the frequency and importance of buried metaplasia, we have conducted a systematic review of reports on endoscopic ablation.
We performed computerized and manual searches for articles on the results of photodynamic therapy (PDT) and radiofrequency ablation (RFA) for Barrett's esophagus. We extracted information on the number of patients treated, biopsy protocol, biopsy depth, and frequency of buried metaplasia.
We found 9 articles describing 34 patients with neoplasia appearing in buried metaplasia (31 after PDT). We found five articles describing a baseline prevalence of buried metaplasia (before ablation) ranging from 0% to 28%. In 22 reports on PDT for 953 patients, buried metaplasia was found in 135 (14.2%); in 18 reports on RFA for 1,004 patients, buried metaplasia was found in only 9 (0.9%). A major problem limiting the conclusions that can be drawn from these reports is that they do not describe specifically how frequently biopsy specimens contained sufficient subepithelial lamina propria to be informative for buried metaplasia.
Endoscopic ablation can bury metaplastic glands with neoplastic potential but, even without ablation, buried metaplasia often is found in areas where Barrett's epithelium abuts squamous epithelium. Buried metaplasia is reported less frequently after RFA than after PDT. However, available reports do not provide crucial information on the adequacy of biopsy specimens and, therefore, the frequency and importance of buried metaplasia after endoscopic ablation remain unclear.
The American Journal of Gastroenterology 08/2011; 106(11):1899-908; quiz 1909. · 9.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To compare the clinical and pathological features of gastro-oesophageal junction (GEJ) carcinomas in Chinese and American patients.
Eighty consecutive patients with a GEJ carcinoma (43 from mainland China, and 37 from the USA) were evaluated for association with Barrett oesophagus (BO), chronic Helicobacter pylori gastritis, intestinal metaplasia, and outcome. GEJ carcinomas were defined as tumours that were located within 20 mm of, and crossed, the GEJ. Overall, GEJ carcinomas from Chinese patients revealed significantly more frequent location in the proximal stomach, higher pathological stage, larger size, younger patient age, and association with chronic H. pylori gastritis. In contrast, GEJ cancers from American patients showed a strong association with distal oesophageal location, BO, and associated intestinal metaplasia and dysplasia. Pathologically, GEJ carcinomas from American patients were predominantly adenocarcinomas, whereas Chinese patients showed a higher proportion of mucinous, adenosquamous, acinar or neuroendocrine tumours. Overall, 3- and 5-year survival rates were statistically similar between both patient groups, but upon multivariate analysis, Chinese patients showed statistically better survival rates for stage III tumours.
Most GEJ carcinomas in patients from China represent proximal gastric cancers associated with chronic H. pylori gastritis, and BO-associated carcinomas are rare among this patient population.