Neil A. Shepherd

Consensus Statements for Management of Barrett's Dysplasia and Early-Stage Esophageal Adenocarcinoma, Based on a Delphi Process

BACKGROUND & AIMS Esophageal adenocarcinoma (EA) is increasingly common among patients with Barretts 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.

Raman spectroscopy, a potential tool for the objective identification and classification of neoplasia in Barrett's oesophagus

Histopathology remains the gold standard technique for the diagnosis of intraepithelial neoplasia (dysplasia) in Barretts oesophagus, but it is highly subjective and relies on blind biopsy targeting. The aim of this study was to evaluate Raman spectroscopy, a rapid, non‐invasive, molecular, specific analytical technique, for the objective identification and classification of Barretts neoplasia in vitro. A secondary objective was to demonstrate the need for a rigorous gold standard in the development of new diagnostic techniques. Forty‐four patients with a mean age of 69 years (range 34–89 years) undergoing surveillance for Barretts oesophagus were included in the study. Three consultant pathologists independently assessed snap‐frozen oesophageal biopsy specimens. Raman spectra were measured on 87 histopathologically homogeneous samples. Spectral classification models were developed using multivariate analysis for the prediction of pathology. Histopathology and Raman classification results were compared. Raman spectral prediction with a consensus pathology classification model gave sensitivities between 73% and 100% and specificities of 90–100%. A high level of agreement (κ = 0.89) was demonstrated between the three‐subset biopsy targeting model and consensus pathology opinion. This compares favourably with the agreement measured between an independent pathologist and the consensus pathology opinion for the same spectra (κ = 0.76). Raman spectroscopy appears to provide a highly sensitive and specific technique for the identification and classification of neoplasia in Barretts oesophagus. Copyright

The prognostic importance of peritoneal involvement in colonic cancer: A prospective evaluation

BACKGROUND & AIMS Prognostic parameters specific to the colon have been somewhat neglected compared with the rectum. This study was instituted to assess the influence of local peritoneal involvement (LPI) on pelvic and intraperitoneal recurrence and prognosis in an unselected, prospective series of colonic cancer resections. METHODS Meticulous examination of 412 resections included evaluation of the relation of the tumor to the peritoneal surface. Histological assessment was as follows: 1, peritoneal involvement absent (81 resections, 20%); 2, inflammatory reaction with tumor close but not present at the surface (89 resections, 22%); 3, peritoneal surface unequivocally infiltrated (112 resections, 27%); and 4, peritoneal involvement with ulceration and tumor cells lying apparently free in the peritoneum (130 resections, 32%). RESULTS LPI showed strong independent prognostic influence in both curative surgery groups and in all patients. In multivariate analysis in curative surgery, LPI was the most powerful prognostic indicator. It was significantly associated with palliative surgery, extent of local spread, and mucinous subtype and predicted cases with subsequent intraperitoneal recurrence and/or persistence. CONCLUSIONS LPI is a common event in colonic cancer and is a consistent predictor of subsequent intraperitoneal recurrence. It is an important independent pathological prognostic parameter and may supersede other parameters in current usage in colonic cancer prognosis.

Raman spectroscopy: elucidation of biochemical changes in carcinogenesis of oesophagus

Several techniques are under development to diagnose oesophageal adenocarcinoma at an earlier stage. We have demonstrated the potential of Raman spectroscopy, an optical diagnostic technique, for the identification and classification of malignant changes. However, there is no clear recognition of the biochemical changes that distinguish between the different stages of disease. Our aim is to understand these changes through Raman mapping studies. Raman spectral mapping was used to analyse 20-μm sections of tissue from 29 snap-frozen oesophageal biopsies. Contiguous haematoxylin and eosin sections were reviewed by a consultant pathologist. Principal component analysis was used to identify the major differences between the spectra across each map. Pseudocolour score maps were generated and the peaks of corresponding loads identified enabling visualisation of the biochemical changes associated with malignancy. Changes were noted in the distribution of DNA, glycogen, lipids and proteins. The mean spectra obtained from selected regions demonstrate increased levels of glycogen in the squamous area compared with increased DNA levels in the abnormal region. Raman spectroscopy is a highly sensitive and specific technique for demonstration of biochemical changes in the carcinogenesis of Barretts oesophagus. There is potential for in vivo application for real-time endoscopic optical diagnosis.

Observer study of the grading of dysplasia in ulcerative colitis: Comparison with clinical outcome

Patients with extensive ulcerative colitis are entered into surveillance programs that aim to detect premalignant changes. Biopsy specimens have been collected in the St Marks Hospital (London) surveillance program over a 22-year-period. Specimens from patients reported as having dysplasia were reexamined. A total of 207 biopsy specimens from 86 patients were graded by five experienced pathologists according to the severity of the dysplasia. The overall agreement between the pathologists grading the specimens was poor; each pair agreed on between 42% and 65% of the slides. The best agreement was for slides that were said to show no dysplasia. Comparison with clinical outcome indicated that the pathologists most likely to diagnose dysplasia in patients with carcinoma were also likely to diagnose dysplasia in patients who did not go on to develop carcinoma. Calculating an average grade of dysplasia did not significantly improve diagnostic accuracy. Despite the findings of this interobserver study, dysplasia has been a successful marker in clinical practice. Pathologists should ensure that they have access to previous slides from the same patient and adequate clinical information before reporting biopsies as positive for dysplasia. An additional biopsy should usually be undertaken before surgery is considered.

The Histopathology of Treated Barrett's Esophagus: Squamous Reepithelialization After Acid Suppression and Laser and Photodynamic Therapy

Columnar metaplasia of the lower esophageal epithelium (Barretts esophagus) occurs in response to acid reflux, and its most important long-term complication is malignancy. In view of this, techniques are being explored for the eradication of Barretts esophagus, and histopathologists will increasingly be required to assess response to these therapies in esophageal biopsy samples. The histopathologic features before and after treatment were studied in biopsy samples from 16 patients receiving omeprazole only, 10 treated by KTP laser photoablation, and five who underwent photodynamic therapy. All the treatment modalities resulted in histologic changes with at least partial squamous reepithelialization of the metaplastic columnar epithelium. The histologic findings suggest three main mechanisms for this: encroachment of adjacent squamous epithelium at the squamocolumnar junction, extension of epithelium from the submucosal gland duct to form squamous islands, and squamous metaplasia within the Barretts columnar mucosa itself. The latter mechanism implies the existence of pluripotential stem cells within Barretts mucosa. A relatively common finding was residual glandular mucosa, nonneoplastic and dysplastic, beneath squamous epithelium indicating the requirement for histologic confirmation of endoscopically suspected complete squamous reepithelialization with sufficiently deep biopsies.

Clonality, Founder Mutations, and Field Cancerization in Human Ulcerative Colitis–Associated Neoplasia

BACKGROUND & AIMS The clonality of colitis-associated neoplasia has not been fully determined. One previous report showed polyclonal origins with subsequent monoclonal outgrowth. We aimed to assess the clonality and mutation burden of individual crypts in colitis-associated neoplasias to try to identify gatekeeping founder mutations, and explore the clonality of synchronous lesions to look for field effects. METHODS Individual crypts (range, 8-21 crypts) were microdissected from across 17 lesions from 10 patients. Individual crypt adenomatous polyposis coli (APC), p53, K-RAS, and 17p loss of heterozygosity mutation burden was established using polymerase chain reaction and sequencing analysis. Serial sections underwent immunostaining for p53, beta-catenin, and image cytometry to detect aneuploidy. RESULTS In most lesions an oncogenic mutation could be identified in all crypts across the lesion showing monoclonality. This founder mutation was a p53 lesion in the majority of neoplasms but 4 tumors had an initiating K-RAS mutation. Some nondysplastic crypts surrounding areas of dysplasia were found to contain clonal p53 mutations and in one case 3 clonal tumors arose from a patch of nondysplastic crypts containing a K-RAS mutation. CONCLUSIONS This study used mutation burden analysis of individual crypts across colitis-associated neoplasms to show lesion monoclonality. This study confirmed p53 mutation as initiating mutation in the majority of lesions, but also identified K-RAS activation as an alternative gatekeeping mutation. Local and segmental field cancerization was found by showing pro-oncogenic mutations in nondysplastic crypts surrounding neoplasms, although field changes are unlikely to involve the entire colon because widely separated tumors were genetically distinct.

Gastric cancer below the age of 55: implications for screening patients with uncomplicated dyspepsia

Aims—To test the hypothesis that gastric cancer presenting with uncomplicated dyspepsia is rare below the age of 55. Patients and methods—The area studied was the postcode defined catchment area of a district general hospital (Gloucestershire Royal) serving a population of 280 500. An open access endoscopy service has been available in this district for more than 17 years. All cases of gastric cancer during a seven year period (1986–92) were drawn from the local pathology database. The database of the neighbouring hospital and the South West Cancer Registry were searched for missed cases from the postcoded area. Hospital and general practitioner records were retrospectively reviewed with respect to duration of symptoms, and previous consultation and investigation for dyspepsia; and alarming symptoms and signs suggestive of underlying malignancy (unexplained recent weight loss, dysphagia, haematemesis or melaena, anaemia, previous gastric surgery, palpable mass, and perforation). Results—Twenty five of 319 cases of gastric cancer detected during the seven year period were aged less than 55. Twenty four of these 25 patients presented with one or more suspicious symptoms or signs. Only one patient (4%) aged less than 55 presented with uncomplicated dyspepsia. In two patients there was a delay in diagnosis of more than six months after first presenting to the general practitioner. Both these patients had significant symptoms at presentation. Conclusion—Gastric cancer is rare below the age of 55 (7.8% of all cases) and, even in the presence of established open access endoscopy, presents with suspicious symptoms or signs in 96% of cases. The age limit for screening uncomplicated dyspepsia can be raised safely to 55.

New relationships between breast microcalcifications and cancer

Background:Breast microcalcifications are key diagnostically significant radiological features for localisation of malignancy. This study explores the hypothesis that breast calcification composition is directly related to the local tissue pathological state.Methods:A total of 236 human breast calcifications from 110 patients were analysed by mid-Fouries transform infrared (FTIR) spectroscopy from three different pathology types (112 invasive carcinoma (IC), 64 in-situ carcinomas and 60 benign). The biochemical composition and the incorporation of carbonate into the hydroxyapatite lattice of the microcalcifications were studied by infrared microspectroscopy. This allowed the spectrally identified composition to be directly correlated with the histopathology grading of the surrounding tissue.Results:The carbonate content of breast microcalcifications was shown to significantly decrease when progressing from benign to malignant disease. In this study, we report significant correlations (P<0.001) between microcalcification chemical composition (carbonate content and protein matrix : mineral ratios) and distinct pathology grades (benign, in-situ carcinoma and ICs). Furthermore, a significant correlation (P<0.001) was observed between carbonate concentrations and carcinoma in-situ sub-grades. Using the two measures of pathology-specific calcification composition (carbonate content and protein matrix : mineral ratios) as the inputs to a two-metric discriminant model sensitivities of 79, 84 and 90% and specificities of 98, 82 and 96% were achieved for benign, ductal carcinoma in situ and invasive malignancies, respectively.Conclusions:We present the first demonstration of a direct link between the chemical nature of microcalcifications and the grade of the pathological breast disease. This suggests that microcalcifications have a significant association with cancer progression, and could be used for future objective analytical classification of breast pathology. A simple two-metric model has been demonstrated, more complex spectral analysis may yeild greater discrimination performance. Furthermore there appears to be a sequential progression of calcification composition.

Influence of local peritoneal involvement on pelvic recurrence and prognosis in rectal cancer.

AIMS--To evaluate the influence of involvement of the peritoneal surface by carcinoma of the rectum on local recurrence and prognosis. METHODS--Prospective analysis of pathological prognostic factors in 209 resections for rectal carcinoma between 1988 and 1993 with meticulous pathological technique particularly to assess the relation of tumour to the peritoneal surface. Comprehensive clinical follow up with cause of death established from all available sources of information (hospital and general practitioner data) with necropsies where necessary. Local recurrence was determined by accepted clinical, radiological and pathological criteria. RESULTS--Local peritoneal involvement was detected in 25.8% (54/209) of cases. It was more common in women and was associated with tumour differentiation, size and site, and lymph node involvement. Local peritoneal involvement showed considerable prognostic disadvantage in all cases and in curative cases alone. Multivariate analysis demonstrated independent prognostic disadvantage for all cases although this was lost in the curative group. With a 30 month median follow up time, comprehensive clinical surveillance detected 25 (12.0%) local recurrences. Thirteen (52%) palliative cases had shown spread to involve the mesorectal (deep, circumferential) resection margin. Of the 12 curative cases, six were upper rectal cancers with local peritoneal involvement suggesting that tumour seeding into the pelvic peritoneal cavity was the cause of local recurrence. Local recurrence of the six other rectal tumours was probably because of intraluminal seeding in two, involvement of the distal margin in one, extensive extramural venous involvement in two, and tumour spread to the bladder in one. CONCLUSIONS--Comprehensive pathological analysis of a resection specimen can identify cases with a high probability of local recurrence which may benefit from early adjuvant therapy. Involvement of the peritoneal surface is a common event in rectal cancer, has adverse prognostic influence and may be an important factor in local recurrence of upper rectal carcinoma.