Biomedical subjects

P Verreet

Publications and source records attributed to P Verreet.

10 recordsLinked to original sources

PubMed2003

[Endoscopic ultrasound in routine clinical practice for staging adenocarcinomas of the stomach and distal esophagus].

PROBLEM: Endoscopic ultrasound (EUS) is an important diagnostic tool for determining the best therapeutic strategy (primary resection, neoadjuvant therapy or palliation only) to offer esophageal or gastric cancer patients. PATIENTS AND METHODS: In the present study (1992-2001),we evaluated the accuracy of EUS in adenocarcinomas of the distal esophagus and stomach and compared our results with pathologists findings as the gold standard. RESULTS: Of the 222 patients studied, the precise examination of 11% EUS was not completely possible due to severe tumor stenosis. The accuracy of EUS with respect to T, N+/- and TN+/- amounted to 51%, 65% and 34% in 131 patients with adenocarcinomas of the esophageal gastric junction and to 50%, 66% and 37% in 91 patients with adenocarcinomas located in the fundus, corpus or antrum of the stomach respectively. With respect to T-stage, the overstaging of tumors was more common than understaging, especially in pT2b-carcinomas. The subgroup analysis of the 131 EGJ adenocarcinoma patients showed that the results obtained by EUS were slightly better in type I (distal esophageal cancer) than in type II and III cardia carcinomas (proximal gastric cancer).When comparing two observation periods (1992-1996 and 1997-2001), the accuracy of endoscopic ultrasound staging was very similar in both periods for T-category (51% vs 49%) and N-category (63% vs 64%) as well as for combined TN-staging (36% vs 35%) respectively. CONCLUSIONS: In clinical routine examinations of adenocarcinomas of the stomach and the distal esophagus, the accuracy of EUS is not as good as the excellent results in the past--mostly obtained under study conditions--may suggest.

Adenocarcinoma↗

PubMed2000

Primary gastric B-cell lymphoma: results of a prospective multicenter study. The German-Austrian Gastrointestinal Lymphoma Study Group.

BACKGROUND & AIMS: Appropriate management of primary gastric lymphoma is controversial. This prospective, multicenter study aimed to evaluate the accuracy of endoscopic biopsy diagnosis and clinical staging procedures and assess a treatment strategy based on Helicobacter pylori status and tumor stage and grade. METHODS: Of 266 patients with primary gastric B-cell lymphoma, 236 with stages EI (n = 151) or EII (n = 85) were included in an intention-to-treat analysis. Patients with H. pylori-positive stage EI low-grade lymphoma underwent eradication therapy. Nonresponders and patients with stage EII low-grade lymphoma underwent gastric surgery. Depending on the residual tumor status and predefined risk factors, patients received either radiotherapy or no further treatment. Patients with high-grade lymphoma underwent surgery and chemotherapy at stages EI/EII, complemented by radiation in case of incomplete resection. RESULTS: Endoscopic-bioptic typing and grading and clinical staging were accurate to 73% and 70%, respectively, based on the histopathology of resected specimens. The overall 2-year survival rates for low-grade lymphoma did not differ in the risk-adjusted treatment groups, ranging from 89% to 96%. In high-grade lymphoma, patients with complete resection or microscopic tumor residuals had significantly better survival rates (88% for EI and 83% for EII) than those with macroscopic tumor residues (53%; P < 0.001). CONCLUSIONS: There is a considerable need for improvement in clinical diagnostic and staging procedures, especially with a view toward nonsurgical treatment. With the exception of eradication therapy in H. pylori-positive low-grade lymphoma of stage EI and the subgroup of locally advanced high-grade lymphoma, resection remains the treatment of choice. However, because there is an increasing trend toward stomach-conserving therapy, a randomized trial comparing cure of disease and quality of life with surgical and conservative treatment is needed.

Adult↗

PubMed1997

Expression of Bax, a pro-apoptotic member of the Bcl-2 family, in esophageal squamous cell carcinoma.

Samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dysplasia (n = 22), carcinoma in situ (n = 15), invasive squamous cell carcinoma (n = 172), lymph-node metastasis (n = 21) and 2 permanent esophageal squamous cell carcinoma cell lines were analyzed immunohistochemically for Bax expression using a polyclonal anti-Bax antibody. Immunostaining was evaluated according to a score system (0-8 points) based on the percentage of positive tumor cells and the relative immunostaining intensity. Cytoplasmatic staining for Bax protein was found uniformly in all cell layers of the normal esophageal squamous epithelium. In contrast, a gradual loss of immunoreactivity for Bax was found in a fraction of pre-neoplastic and neoplastic lesions. Upon comparison of the amount of Bax expression between the different types of lesion, however, no significant differences were found between severe squamous cell dysplasias, carcinomas in situ, invasive carcinomas and lymph-node metastases. In both esophageal carcinoma cell lines, immunoreactivity for Bax was found and confirmed by means of Northern blot analysis. In invasive carcinomas, Bax immunoreactivity was inversely correlated with Bcl-2 expression (p = 0.0243) and decreased continuously with decreasing tumor differentiation (p = 0.0011). No correlation was found between Bax expression and the following parameters: depth of invasion, nodal status and tumor size. Bax expression had no influence on the post-operative survival of esophageal cancer patients.

Adult↗

PubMed1997

Basaloid squamous cell carcinoma of the esophagus: diagnosis and prognosis.

BACKGROUND: Basaloid squamous cell carcinoma (BSCC) is a recently recognized, poorly differentiated variant of squamous cell carcinoma (SCC), which is located predominantly in the upper aerodigestive tract. METHODS: In this study, clinical and pathologic parameters of 17 BSCCs and 133 typical SCCs of the esophagus that underwent potentially curative resection (no distant metastases, no residual tumor) were compared. In addition, light microscopic, electron microscopic, and immunohistochemical features of BSCC were investigated, to determine whether this type of carcinoma could be differentiated from other poorly differentiated carcinomas of the esophagus. RESULTS: Light microscopic study showed that BSCC was composed of relatively small tumor cells, arranged in solid lobules with abundant comedo-type necrosis. BSCC was almost invariably accompanied by areas of concomitant typical SCC, foci of squamous cell differentiation, and/or severe squamous cell dysplasia or carcinoma in situ of the adjacent mucosa. Ultrastructurally, BSCC inconsistently showed features of squamous cell differentiation. Immunohistochemically, BSCC displayed poor reactivity for antibodies against wide-range cytokeratins and cytokeratin subtypes that are typical of squamous cell epithelia (cytokeratin 13 and cytokeratin 14). Infrequently, expression of Leu7, smooth muscle actin, and S-100 protein was found. In comparison with typical SCC, the characteristic features of BSCC were older patient age, higher proliferative activity (MIB-1 labelling index), and higher apoptotic indices. No differences were found with regard to pT classification, pN classification, tumor size, blood vessel invasion, lymphatic vessel invasion, neural invasion, or patient gender. Moreover, no differences in overall survival rates were found. CONCLUSIONS: BSCC is a distinct histopathologic variant of SCC, characterized by a poor degree of differentiation and high proliferative activity. However, after potentially curative resection, the prognosis of patients with BSCC of the esophagus does not differ from that of patients with typical SCC.

Actins↗

PubMed1997

Prognostic significance of urokinase-type plasminogen activator expression in squamous cell carcinomas of the esophagus.

In the present study, urokinase-type plasminogen activator (uPA) expression in 150 potentially curatively resected SCCs of the esophagus was analyzed immunohistochemically by means of a murine monoclonal antibody (American Diagnostica, Greenwich, CT) and correlated with survival. Altogether, 122 of the 150 tumors (81.3%) expressed different levels of uPA. Among the 122 uPA-positive tumors, 104 (85.2%) showed a weak staining intensity, and 18 (14.8%) showed a strong staining intensity. Among the uPA-positive tumors, 29 (23. 8%) tumors showed a uPA immunoreactivity in 6-25% of all tumor cells, 30 (24.6%) showed a uPA immunoreactivity in 26-50% of all tumor cells, 41 (33.6%) showed a uPA immunoreactivity in 51-75% of all tumor cells, and 22 (18.0%) showed a uPA immunoreactivity in 76-100% of all tumor cells. No significant correlation could be shown between the different patterns of uPA expression and various clinicopathological parameters, such as pT category, pN category, tumor size, histological grade, blood vessel invasion, lymphatic vessel invasion, and inflammatory response. Concerning the overall postoperative survival, no significant differences between uPA-positive and uPA-negative tumors could be verified. This also held true when different cut points in the percentage of uPA-positive tumor cells were used. In contrast, the intensity of uPA staining provided significant prognostic information in that patients with strongly uPA-positive tumors had a poorer outcome than patients with weakly uPA-positive or uPA-negative tumors. Moreover, as shown by stepwise multivariate Cox regression analysis, the intensity of uPA expression was an independent prognostic factor.

Adult↗

PubMed1996

bcl-2 expression and prognosis in squamous-cell carcinomas of the esophagus.

The bcl-2 proto-oncogene is a known inhibitor of apoptosis and may be an important regulator of tumor growth. In the present study, bcl-2-protein expression was investigated by immunohistochemistry and correlated with prognosis in a series of 150 potentially curatively resected squamous-cell carcinomas of the esophagus. For comparison, bcl-2-protein expression was analyzed in normal esophageal mucosa, severe squamous dysplasias and carcinomas in situ. bcl-2 immunoreactivity was found in 40 out of 150 invasive squamous-cell carcinomas; the remaining carcinomas were completely negative. bcl-2-protein expression was found more frequently among poorly differentiated than among well-differentiated tumors (p < 0.0001). No correlation was found between bcl-2-protein expression and the parameters tumor size, depth of invasion and nodal status. Moreover, bcl-2-protein expression had no significant influence on overall survival. Whereas in normal mucosa bcl-2 immunoreactivity was restricted to the basal-cell layer, in 9 out of 15 severe squamous dysplasias and in 7 out of 14 carcinomas in situ bcl-2 staining was detected in all epithelial layers. Thus, bcl-2-protein is frequently expressed in invasive squamous-cell carcinomas of the esophagus and in precursor lesions of esophageal cancer, but has no significant impact on the outcome of esophageal cancer.

Adult↗

PubMed1996

[Clinical standardization in acute abdominal pain].

The correct diagnosis in acute abdominal pain is necessary for adequate treatment. In several clinical studies it has been shown that, despite improvements in laboratory and technology medicine, errors occur in a considerable proportion of cases due to insufficient history-taking and clinical examination. By the introduction of a standardised and structured history and clinical examination, the diagnostic accuracy can be improved by at least 10%. The aim of this publication is to improve history-taking, clinical examination and diagnostic decision-making by exact definition of all relevant parameters. This was performed by a national clinical expert group, international standardisations were taken in consideration. The standardisation was based mainly on these existing international standardisations (World Organisation of Gastroenterology); however, revisions and corrections were necessary. In order to introduce the standardisation into clinical routine, a documentation form and a documentation program can be provided.

Abdomen, Acute↗

PubMed1992

[Cholecystectomy through laparotomy].

Laparotomy cholecystectomy is the "gold standard operation". Its mortality is almost nil. Its morbidity dramatically decreased while digestive surgery was improving. Alternative therapies are to be compared to it. Indications of laparotomy cholecystectomy remain frequent today but will decrease promptly due to the functional and cosmetic benefits of coelioscopic cholecystectomy.

Cholecystectomy↗

PubMed1987

[Postoperative recurrent gastroduodenal ulcer: pathogenesis--reinterventions--results].

High 10-year recurrence rates following proximal gastric vagotomy (PGV) for pyloric/prepyloric ulcer (31.6%, European trial) result from antral stasis (Dragstedt-mechanism). Additional pyloroplasty reduces the recurrence rate to 16.6%. General causes of recurrence following PGV are primarily incomplete vagotomy and smoking: For incomplete vagotomy (Burge-test) 24.4% recurrences, for complete vagotomy 13.6% (10-year results); in smokers 38%, non-smokers 12%. Therapy is conservative in 80%. Selective gastric revagotomy and antrectomy as reoperation shows lowest recurrence rate (1.2%). The major cause of recurrence after partial gastrectomy is inadequate resection. Conservative therapy is successful in 76%. Reoperation should be transthoracic vagotomy with no mortality in 11 centers.

Gastrectomy↗

PubMedDate not supplied

The prognostic significance of epidermal growth factor receptor expression in squamous cell carcinomas of the oesophagus.

EGFR expression in 150 potentially curative resected squamous cell carcinomas of the oesophagus was analyzed immunohistochemically and correlated with survival. Altogether, 124 of 150 (82.7%) tumours expressed different levels of EGFR. The percentage of tumour cells expressing EGFR varied greatly between the different tumours (median: 70%). 62 (50.0%) tumours showed weak and intense staining, respectively. Regarding the staining pattern 19 (15.3%) tumours showed exclusively membraneous immunoreactivity, 27 (21.8%) an exclusively cytoplasmic immunoreactivity and 78 (62.9%) a mixed staining pattern. No significant correlation however could be found between EGFR expression and various clinicopathologic parameters such as pT category, pN category, tumour size, histologic grade and blood vessel invasion. In univariate survival analysis, no correlation between EGFR expression and postoperative survival time was observed. In a forward multivariate Cox regression analysis only the parameters lymphatic-vessel invasion (p = 0.001), pT category (p = 0.0034) and pN category (p = 0.0256), but not the EGFR expression, could be verified as independent prognostic variables. In conclusion, the evaluation of the EGFR expression does not provide prognostic information for patients who underwent potentially curative resection for SCC of the oesophagus.

Adult↗