Biomedical subjects

J Jan B Van Lanschot

Publications and source records attributed to J Jan B Van Lanschot.

5 recordsLinked to original sources

PubMed2006

Role of positron emission tomography in the (re-)staging of oesophageal cancer.

BACKGROUND: Various studies have demonstrated that 18F-Fluorodeoxyglucose-positron emission tomography (FDG-PET), measuring altered tissue glucose metabolism, is a promising non-invasive method for detecting both distant nodal and haematogenous metastases in patients with oesophageal carcinoma (OC) and might thus prevent futile esophagectomy. Moreover, FDG-PET is a promising tool in assessing response to non-surgical treatment, and might therefore be used for an early decision on whether treatment should be stopped or continued. MATERIAL AND METHODS: Review of the recent literature regarding the diagnostic performance of FDG-PET in the preoperative staging of patients with OC and regarding diagnostic accuracy of FDG-PET in assessing response to neoadjuvant therapy in patients with OC compared to conventional techniques (especially computed tomography (CT) and endoscopic ultrasonography (EUS)). RESULTS: A search of the literature resulted in the inclusion of 16 studies on the diagnostic value of FDG-PET. Sensitivity and specificity for the detection of locoregional metastases were moderate. Sensitivity and specificity were reasonable for distant metastases. The diagnostic accuracy of FDG-PET in assessing response to treatment was similar to the accuracy of EUS, but significantly higher than that of CT. CONCLUSIONS: The staging value of FDG-PET in OC patients is limited in the detection of locoregional metastases; however; its value is higher in the detection of distant lymphatic and haematogenous metastases. Moreover, FDG-PET is a valuable tool for the non-invasive assessment of histopathologic tumour response after neoadjuvant therapy..

Adenocarcinoma↗

PubMed2006

Variable mannose-binding lectin expression during postoperative acute-phase response.

BACKGROUND: Low plasma concentrations and genetic polymorphisms of mannan-binding lectin (MBL) have been associated with infectious disease complications during various conditions. The present study examined the nature and expression of MBL deficiency during a surgery-induced acute-phase response. METHODS: Blood was sampled from 20 consecutive patients before and 1, 3, 5, 7, and 10 days and 6 weeks after a uniform abdominal operation (transhiatal esophagectomy). Plasma concentrations of MBL, C-reactive protein (CRP), and secretory phospholipase A2 (sPLA2) were measured. Patients were classified as low- or high-level MBL producers by their preoperative concentration (<0.5 or > or = 0.5 micrograms/mL), and were cross-verified for actual MBL deficiency by nucleotide sequencing of both the MBL promoter and exon-1 alleles. RESULTS: Baseline plasma MBL concentrations correlated with maximal postoperative plasma concentrations (r = 0.88; p < 0.0001). This was not found for CRP and sPLA2 (r = 0.19 and r = 0.08, respectively). Alleles responsible for structural MBL variants were detected in 40% of patients and were associated with significantly reduced MBL concentrations (p = 0.005). The baseline cut-off value in plasma of 0.5 micrograms/mL clearly identified individuals with variant exon-1 alleles (sensitivity 100%, specificity 83%). CONCLUSIONS: Baseline MBL plasma concentrations are predictive of MBL expression during the acute-phase response. A baseline cut-off value of 0.5 micrograms/mL can be used to identify patients with variants in the exon-1 region of the MBL gene without the need for nucleotide sequencing. Clinical studies may use this easy and quick method to identify MBL deficient patients preoperatively, as they are conditionally at risk for infectious complications.

Acute-Phase Reaction↗

PubMed2005

Gene therapy for barrett's esophagus: adenoviral gene transfer in different intestinal models.

Adenoviral gene therapy could potentially be used for treatment of patients with a Barrett's esophagus. In order to study the feasibility of this approach it is important to study adenoviral intestinal transduction both in vitro and in vivo. In the present study, we used differentiating Caco-2 cells, closed intestinal loops and a Barrett's esophagus rat model to test transduction of adenoviruses expressing green fluorescent protein. We observed a decreased adenoviral transduction from 18.6 to 2.3% in undifferentiated and differentiated Caco-2 cells, respectively. This could be improved by the use of the mucolytic agent N-acetylcysteine (NAC) and the polycation diethylaminoethyl-dextran (DEAE-dextran), which improved transduction in differentiated cells five- and ten-fold, respectively. Also an RGD-retargeted adenovirus showed an improved transduction in differentiated cells. In closed intestinal loops adenoviral transduction was limited and the use of NAC and DEAE-dextran or RGD targeting had little effect. The Barrett's esophagus rat model consisted of an esophagojejunostomy, which results in a Barrett's esophagus and esophageal tumors within 6 months. Adenoviral transduction in this model was limited and mainly localized in the basal layer of normal esophagus and stromal tissue of a Barrett's segment. We conclude that although the adenovirus shows promising results in vitro, the current adenoviral vectors are probably not suitable for patients with Barrett's esophagus.

Acetylcysteine↗

PubMed2003

Cyclooxygenase-2 and gastric carcinogenesis.

Epidemiological studies have shown that the use of nonsteroid anti-inflammatory drugs (NSAIDs) is associated with reduced risk of gastric cancer. The best-known target of NSAIDs is the cyclooxygenase (Cox) enzyme. Two Cox genes have been cloned, of which Cox-2 has been connected with gastric carcinogenesis. Expression of Cox-2 is elevated in gastric adenocarcinomas, which correlates with several clinicopathological parameters, including depth of invasion and lymph node metastasis. This suggests that Cox-2-derived prostanoids promote aggressive behavior of adenocarcinomas of the stomach. Cox-2 expression is especially prominent in intestinal-type gastric carcinoma and it is already present in dysplastic precursor lesions of this disease, which suggests that Cox-2 contributes to gastric carcinogenesis already at the preinvasive stage. Our most recent data show that Cox-2 is expressed in gastric adenomas of trefoil factor 1 deficient mice. Treatment of these mice with a Cox-2 selective inhibitor, celecoxib, reduced the size of the adenomas. Taken together these data support efforts to initiate clinical studies to investigate the effect of Cox-2 inhibitors as chemotherapeutic agents and as adjuvant treatment modalities against gastric neoplasias.

Adenocarcinoma↗

PubMed2002

Prognostic significance of elevated cyclooxygenase 2 expression in patients with adenocarcinoma of the esophagus.

BACKGROUND & AIMS: Use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a reduced risk of cancer in the digestive tract. Cyclooxygenase (COX) is the best-known target of NSAIDs, and expression of the COX-2 isoform is elevated in esophageal carcinomas but its clinical significance remains unclear. We examined COX-2 expression in esophageal adenocarcinomas and its relation to clinicopathologic parameters. METHODS: Tumor sections from 145 consecutive patients undergoing intentionally curative surgery for an adenocarcinoma arising from a Barrett's esophagus were immunohistochemically stained using a COX-2-specific anti-human monoclonal antibody. The specimens were scored based on the intensity and extent of COX-2 immunopositivity. RESULTS: COX-2 immunoreactivity was negative to weak in 21% (COX-2 low) and moderate to strong in 79% (COX-2 high) of the carcinomas. Patients with high COX-2 expression were more likely to develop distant metastases (P = 0.02) and local recurrences (P = 0.05), and survival was significantly reduced (P = 0.002, log-rank test) among patients with high COX-2 expression when compared with the COX-2 low group. Five-year survival rates were 35% (95% confidence interval [CI], 23-47) and 72% (95% CI, 53-90) in COX-2 high and COX-2 low categories, respectively. Furthermore, expression of COX-2 was recognized as an independent prognostic factor by multivariate analysis (relative risk, 3.5; 95% CI, 1.6-7.9). CONCLUSIONS: Elevated expression of COX-2 protein is associated with significantly reduced survival of patients undergoing surgery for esophageal adenocarcinoma. These findings support the effort to initiate clinical studies to investigate the effect of COX-2 inhibitors as a novel (adjuvant) chemotherapeutic modality for the treatment of adenocarcinoma arising from Barrett's esophagus.

Adenocarcinoma↗