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Featured researches published by M. F. Dixon.


The American Journal of Surgical Pathology | 1996

Classification and grading of Gastritis: The updated Sydney system

M. F. Dixon; Robert M. Genta; John H. Yardley; Pelayo Correa

The Sydney System for the classification of gastritis emphasized the importance of combining topographical, morphological, and etiological information into a schema that would help to generate reproducible and clinically useful diagnoses. To reappraise the Sydney System 4 years after its introduction, a group of gastrointestinal pathologists from various parts of the world met in Houston, Texas, in September 1994. The aims of the workshop were (a) to establish an agreed terminology of gastritis; (b) to identify, define, and attempt to resolve some of the problems associated with the Sydney System. This article introduces the Sydney System as it was revised at the Houston Gastritis Workshop and represents the consensus of the participants. Overall, the principles and grading of the Sydney System were only slightly modified, the grading being aided by the provision of a visual analogue scale. The terminology of the final classification has been improved to emphasize the distinction between the atrophic and nonatrophic stomach; the names used for each entity were selected because they are generally acceptable to both pathologists and gastroenterologists. In addition to the main categories and atrophic and nonatrophic gastritis, the special or distinctive forms are described and their respective diagnostic criteria are provided. The article includes practical guidelines for optimal biopsy sampling of the stomach, for the use of the visual analogue scales for grading the histopathologic features, and for the formulation of a comprehensive standardized diagnosis. A glossary of gastritis-related terms as used in this article is provided.


The Lancet | 1986

LOCAL RECURRENCE OF RECTAL ADENOCARCINOMA DUE TO INADEQUATE SURGICAL RESECTION: Histopathological Study of Lateral Tumour Spread and Surgical Excision

P. Quirke; M. F. Dixon; Paul Durdey; N.S. Williams

In 52 patients with rectal adenocarcinoma whole-mount sections of the entire operative specimen were examined by transverse slicing. There was spread to the lateral resection margin in 14 of 52 (27%) patients and 12 of these proceeded to local pelvic recurrence. The specificity, sensitivity, and positive predictive values were 92%, 95%, and 85%, respectively. In a retrospective stage-matched and grade-matched control group there was local recurrence in the same proportion of patients, but in this series no patient had been shown by routine sampling to have lateral spread. In rectal adenocarcinoma, local recurrence is mainly due to lateral spread of the tumour and has previously been underestimated.


Gut | 2000

The Vienna classification of gastrointestinal epithelial neoplasia

Ronald J. Schlemper; Robert H. Riddell; Yo Kato; F Borchard; H S Cooper; S M Dawsey; M. F. Dixon; C M Fenoglio-Preiser; Jean-François Fléjou; Karel Geboes; Toshio Hattori; T Hirota; Masayuki Itabashi; M Iwafuchi; Akinori Iwashita; Y I Kim; T Kirchner; M Klimpfinger; Morio Koike; Gregory Y. Lauwers; Klaus J. Lewin; Georg Oberhuber; F Offner; A B Price; Carlos A. Rubio; Michio Shimizu; Tadakazu Shimoda; Pentti Sipponen; E Solcia; Manfred Stolte

BACKGROUND Use of the conventional Western and Japanese classification systems of gastrointestinal epithelial neoplasia results in large differences among pathologists in the diagnosis of oesophageal, gastric, and colorectal neoplastic lesions. AIM To develop common worldwide terminology for gastrointestinal epithelial neoplasia. METHODS Thirty one pathologists from 12 countries reviewed 35 gastric, 20 colorectal, and 21 oesophageal biopsy and resection specimens. The extent of diagnostic agreement between those with Western and Japanese viewpoints was assessed by kappa statistics. The pathologists met in Vienna to discuss the results and to develop a new consensus terminology. RESULTS The large differences between the conventional Western and Japanese diagnoses were confirmed (percentage of specimens for which there was agreement and kappa values: 37% and 0.16 for gastric; 45% and 0.27 for colorectal; and 14% and 0.01 for oesophageal lesions). There was much better agreement among pathologists (71% and 0.55 for gastric; 65% and 0.47 for colorectal; and 62% and 0.31 for oesophageal lesions) when the original assessments of the specimens were regrouped into the categories of the proposed Vienna classification of gastrointestinal epithelial neoplasia: (1) negative for neoplasia/dysplasia, (2) indefinite for neoplasia/dysplasia, (3) non-invasive low grade neoplasia (low grade adenoma/dysplasia), (4) non-invasive high grade neoplasia (high grade adenoma/dysplasia, non-invasive carcinoma and suspicion of invasive carcinoma), and (5) invasive neoplasia (intramucosal carcinoma, submucosal carcinoma or beyond). CONCLUSION The differences between Western and Japanese pathologists in the diagnostic classification of gastrointestinal epithelial neoplastic lesions can be resolved largely by adopting the proposed terminology, which is based on cytological and architectural severity and invasion status.


Annals of Surgery | 2002

Rates of Circumferential Resection Margin Involvement Vary Between Surgeons and Predict Outcomes in Rectal Cancer Surgery

K Birbeck; Christopher P. Macklin; Nicholas J. Tiffin; Wendy Parsons; M. F. Dixon; N P Mapstone; Cedric R. Abbott; Nigel Scott; P. J. Finan; D. Johnston; P. Quirke

ObjectiveTo analyze the potential variability in rates of circumferential resection margin (CRM) involvement between different surgeons and time periods and to determine the suitability of using CRM status as an immediate predictor of outcome after rectal cancer surgery. Summary Background DataAfter disease stage has been taken into account, survival in rectal cancer has been shown to be very variable between surgeons and institutions. One of the major factors influencing survival is local recurrence, and this in turn is strongly related to inadequate tumor excision, particularly at the CRM. MethodsIn a study involving 608 patients who underwent surgery for rectal cancer in Leeds during the 12-year period 1986 to 1997, the authors examined the role of CRM status as an immediate predictor of likely outcome, paying particular attention to its relationships with different surgeons and time periods. ResultsOf 586 patients on whom full clinical follow-up was obtained, 165 (28.2%) had CRM involvement by carcinoma on pathologic examination. Up to the end of 1998, 105 (17.9%) patients had developed local recurrence. A significantly higher proportion (38.2%) of CRM-positive patients developed local recurrence than CRM-negative ones (10.0%). Kaplan-Meier survival analysis showed significant improvements in survival for CRM-negative patients over CRM-positive patients. Survival analysis in relation to two gastrointestinal surgeons and a group of other surgeons showed survival improvements that paralleled a reduction in the rates of CRM involvement for the two gastrointestinal surgeons during the period of the study. No improvement in survival or reduction in rates of CRM involvement was seen in the group of other surgeons. ConclusionsThese results show that CRM status may be used as an immediate predictor of survival after rectal cancer surgery and serves as a useful indicator of the quality of surgery. The frequency of CRM involvement can be used both for overall surgical audit and for monitoring the value of training programs in improving rectal surgery by individual surgeons. Its use in the current MRC CR07 study is valid and the best indicator of a requirement for further local therapy.


Annals of Surgery | 2005

The Modern Abdominoperineal Excision: The Next Challenge After Total Mesorectal Excision

Roger Marr; K Birbeck; James Garvican; Christopher P. Macklin; Nicholas J. Tiffin; Wendy Parsons; M. F. Dixon; N P Mapstone; David Sebag-Montefiore; Nigel Scott; D. Johnston; P. M. Sagar; P. J. Finan; P. Quirke

Objectives:Examine the cause of local recurrence (LR) and patient survival (S) following abdominoperineal resection (APR) and anterior resection (AR) for rectal carcinoma and the effect of introduction of total mesorectal excision (TME) on APR. Methods:A total of 608 patients underwent surgery for rectal cancer in Leeds from 1986 to 1997. CRM status and follow-up data of local recurrence and patient survival were available for 561 patients, of whom 190 underwent APR (32.4%) and 371 AR (63.3%). Also, a retrospective study of pathologic images of 93 specimens of rectal carcinoma. Results:Patients undergoing APR had a higher LR and lower survival (LR, 22.3% versus 13.5%, P = 0.002; S, 52.3% versus 65.8%, P = 0.003) than AR. LR free rates were lower in the APR group and cancer specific survival was lowered (LR, 66% versus 77%, log rank P = 0.03; S, 48% versus 59%, log rank P = 0.02). Morphometry: total area of surgically removed tissue outside the muscularis propria was smaller in APR specimens (n = 27) than AR specimens (n = 66) (P < 0.0001). Linear dimensions of transverse slices of tissue containing tumor, median posterior, and lateral measurements were smaller (P < 0.05) in the APR than the AR group. APR specimens with histologically positive CRM (n = 11) had a smaller area of tissue outside the muscularis propria (P = 0.04) compared with the CRM-negative APR specimens (n = 16). Incidence of CRM involvement in the APR group (41%) was higher than in the AR group (12%) (P = 0.006) in the 1997 to 2000 cohort. Similar results (36% and 22%) were found in the 1986 to 1997 cohort (P = 0.002). Conclusions:Patients treated by APR have a higher rate of CRM involvement, a higher LR, and poorer prognosis than AR. The frequency of CRM involvement for APR has not diminished with TME. CRM involvement in the APR specimens is related to the removal of less tissue at the level of the tumor in an APR. Where possible, a more radical operation should be considered for all low rectal cancer tumors.


Gut | 1991

Acute Helicobacter pylori infection: clinical features, local and systemic immune response, gastric mucosal histology, and gastric juice ascorbic acid concentrations.

G. M. Sobala; J. E. Crabtree; M. F. Dixon; C. J. Schorah; J. D. Taylor; B. J. Rathbone; R V Heatley; A. T. R. Axon

The symptomatology of a case of acute infection with Helicobacter pylori is described, together with the accompanying changes in gastric mucosal histology, local and systemic humoral immune response, and gastric ascorbic acid concentration. The patient was an endoscopist, previously negative for the carbon-14 urea breath test, who had a week of epigastric pain and then became asymptomatic. H pylori was detected by culture of antral biopsy specimens and was still present after 74 days. Five days after infection the histological findings showed acute neutrophilic gastritis; by day 74 changes of chronic gastritis were evident. The patient seroconverted by IgG enzyme linked immunosorbent assay by day 74, but a mucosal IgM and IgA response was evident as early as day 14. Infection was accompanied by a transient hypochlorhydria but a sustained fall in gastric juice ascorbic acid concentration.


The American Journal of Surgical Pathology | 2000

Gastric dysplasia: the Padova international classification.

Massimo Rugge; Pelayo Correa; M. F. Dixon; Takanori Hattori; Gioacchino Leandro; Klaus J. Lewin; Robert H. Riddell; Pentii Sipponen; Hidenobu Watanabe

A worldwide-accepted histologic, classification of the gastric carcinomatous and precancerous lesions is a prerequisite for a consistent recording of epidemiologic data and for both developing and evaluating primary and secondary preventive efforts. Different nomenclatures have been proposed for gastric precancerous lesions in eastern countries and in Japan. This article presents a classification of gastric precancerous lesions resulting from an international consensus conference involving pathologists of different countries. Five main diagnostic categories are identified. To allow comparisons with the nomenclature proposed by the Japanese Research Society for Gastric Cancer, each category was also assigned a numeric identification: 1 = normal, 2 = indefinite for dysplasia, 3 = noninvasive neoplasia, 4 = suspicious for invasive cancer, and 5 = cancer. The interobserver reproducibility of the histologic classification was tested in a series of 46 cases. By collapsing benign alterations (categories 1+2) versus noninvasive neoplasia (category 3) versus suspicious for invasive cancer and fully appearing carcinomatous lesions (categories 4+5), the general agreement value was 77.7%, whereas kappa coefficient was 0.63. By examining gastric precancerous lesions from diverse populations, the authors agreed that the gastric precancerous process is universal and the differences in nomenclatures are merely semantics. The international Padova classification of the gastric precancerous lesions is submitted to the attention of the international scientific community, which is invited to test and to improve on it.


International Journal of Colorectal Disease | 1988

The prediction of local recurrence in rectal adenocarcinoma by histopathological examination

P. Quirke; M. F. Dixon

Local recurrence of rectal adenocarcinoma is mainly due to failure to remove all the tumour. A method is described for the routine detection of involvement of the circumferential (lateral) resection margin. Current definitions of the length of the rectum are inadequate for the assessment of the risk of local recurrence as the rectum frequently extends higher than 15 cm. Use of the term recto-sigmoid should be replaced clinically by sigmoidoscopic measurement of the height of a tumour and pathologically by its anatomical relationship to the level of peritoneal reflection, i.e. lower or upper segment of the rectum or the sigmoid colon. Tumours above the peritoneal reflection (upper segment) are at risk of circumferential resection margin involvement due to their retroperitoneal component. The amount of tissue excised varies considerably from surgeon to surgeon. Meticulous attention to the clearance of the tumour at the circumferential resection margin is essential if local recurrence rates are to be reduced. A trial of postoperative radiotherapy should be instigated based on the pathologists identification of patients at high risk of local recurrence.


Journal of Clinical Pathology | 1987

Campylobacter pyloridis and acid induced gastric metaplasia in the pathogenesis of duodenitis.

J I Wyatt; B J Rathbone; M. F. Dixon; R V Heatley

Biopsy specimens of gastric and duodenal mucosa from 290 patients were examined histologically for metaplasia and Campylobacter pyloridis. Estimates of pH on samples of fasting gastric juice from 55 of the patients were performed, and mucosal biopsy specimens from 33 patients were also cultured for C pyloridis. Active duodenitis was seen in 34 duodenal biopsy specimens. Thirty (88%) of the patients with active duodenitis had both greater than 5% gastric metaplasia in the duodenal specimen and C pyloridis associated gastritis. These two factors coexisted in only 0.43% of patients with no duodenal inflammation. When C pyloridis were seen histologically in duodenal biopsy specimens they were confined to areas of gastric metaplasia and never occurred in the absence of a polymorph infiltrate. Of the 55 patients with measurements of gastric juice pH, gastric metaplasia was present in the duodenum in 20 of 42 with a pH of less than 2.5, and in 0 of 13 with a pH of greater than 2.5. These results suggest that acid induced gastric metaplasia in the duodenum and C pyloridis associated gastritis may be synergistic in the pathogenesis of duodenitis; the metaplastic gastric epithelium allows C pyloridis to colonise the duodenal mucosa, where it produces an acute inflammatory response.


Diseases of The Colon & Rectum | 1998

Circumferential margin involvement after mesorectal excision of rectal cancer with curative intent-predictor of survival but not local recurrence?

N. R. Hall; P. J. Finan; T. Al‐Jaberi; C. S. Tsang; Sarah Brown; M. F. Dixon; P. Quirke

PURPOSE: This study examines the prognostic significance of circumferential margin involvement by tumor in resected specimens after potentially curative rectal cancer surgery. METHODS: During an eight-year period, all patients with rectal cancer were prospectively audited. For tumors of the middle and lower thirds of the rectum, a total mesorectal excision was performed; for tumors of the upper third, mesorectal excision proceeded at least 5 cm distal to the primary tumor. Resected specimens were subjected to careful histologic assessment, and patients undergoing curative procedures were entered into a surveillance program to detect both local and distant recurrence. RESULTS: Of 218 patients in the cohort, 9 had no resection, 14 underwent local excision, 1 had pre-operative radiotherapy, and 42 patients (20 percent) had palliative resections and were excluded from further analysis. This left 152 patients having a curative resection, of whom 20 (13 percent) had tumor within 1 mm of the circumferential margin. After follow-up until death or a median period of 41 months, recurrent disease was seen in 24 percent of patients with a negative margin and 50 percent with a positive margin. Both disease-free survival and mortality were significantly related to margin involvement (log-rank,P=0.01 andP=0.005, respectively). Local recurrence, however, was not significantly different in the two groups (11 and 15 percent, respectively; log-rank,P=0.38). CONCLUSIONS: When a mesorectal excision is performed, circumferential margin involvement is more an indicator of advanced disease than inadequate local surgery. Patients with an involved margin may die from distant disease before local recurrence becomes apparent.

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Jean E. Crabtree

St James's University Hospital

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Judith I. Wyatt

St James's University Hospital

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