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Featured researches published by Jan Dees.


Gut | 1996

Oesophageal cancer is an uncommon cause of death in patients with Barrett's oesophagus

A. Van Der Burgh; Jan Dees; Wim C. J. Hop; M. van Blankenstein

BACKGROUND: Barretts oesophagus carries a 30-fold to 40-fold increased risk of oesophageal cancer. It is unknown whether endoscopic surveillance programmes reduce mortality from oesophageal cancer. METHODS: A cohort study was undertaken of all 166 patients in whom the diagnosis Barretts oesophagus had been established between 1973 and 1986. RESULTS: One hundred and fifty five of 166 patients could be traced (93%). During a mean follow up of 9.3 years (amounting to 1440 patient years) eight patients had developed oesophageal cancer at random intervals (one case in 180 patient years). All but one of the tumours were diagnosed at endoscopy for symptoms, three in the stage of carcinoma in situ. Risk factors for the development of oesophageal cancer were extensive Barretts oesophagus exceeding 10 cm (p = 0.02) and Barretts ulcer at the time of intake (p = 0.009). Seventy six patients were alive; three had undergone surgery for oesophageal cancer and were without recurrence respectively, 12.8 years, 12.1 years, and 7 months postoperatively. Seventy nine patients had died; five of them had developed oesophageal cancer, but in only two cases this had been the cause of death (2.5%). CONCLUSIONS: Oesophageal cancer is an uncommon cause of death in patients with Barretts oesophagus. The patients of this cohort would not have benefited from an endoscopic surveillance programme.


Gastroenterology | 1987

Abnormal pattern of cell proliferation in the entire colonic mucosa of patients with colon adenoma or cancer

Onno T. Terpstra; Mark van Blankenstein; Jan Dees; Guus A.M. Eilers

Using autoradiography after 1 h of pulsed labeling with tritiated thymidine in endoscopic biopsy specimens from normal-appearing mucosa, cell proliferation was determined at six predetermined sites of the whole colon in patients with neoplastic disease of the large bowel and was compared with that of subjects without macroscopic colonic pathology. The labeling index (the percentage of cells incorporating [3H]thymidine) was 8.6 +/- 0.5 (mean +/- SEM) in 13 patients with colon carcinoma (p less than 0.001 vs. 16 control patients whose labeling index was 4.9 +/- 0.2) and 9.1 +/- 0.4 in 11 patients with a large adenoma in the colon (p less than 0.001 vs. controls). Twenty-one patients with one or more small adenomas (diameter less than 1 cm) had a moderately increased cell proliferation compared with controls (labeling index 6.2 +/- 0.3, p less than 0.02 vs. controls). In patients with neoplastic disease an enlargement of the proliferative compartment was found, whereas 6 patients with Crohns colitis had values for labeling index and a distribution of labeled cells along the crypt comparable to that of control subjects. An increased cell proliferation was found along the entire colon under each of the neoplastic conditions studied. These findings indicate that although neoplastic lesions develop in a limited area of the colon, the entire large bowel may be at risk for tumor growth.


Clinical Infectious Diseases | 2004

Resurgence of Lymphogranuloma Venereum in Western Europe: An Outbreak of Chlamydia trachomatis Serovar L2 Proctitis in The Netherlands among Men Who Have Sex with Men

Rutger F. Nieuwenhuis; Jacobus M. Ossewaarde; Hannelore Götz; Jan Dees; H. Bing Thio; Maarten Thomeer; Jan C. den Hollander; Martino Neumann; Willem I. van der Meijden

BACKGROUND Lymphogranuloma venereum (LGV) is a sexually transmitted disease (STD) and is rare in the Western world. Recently, 3 men who have sex with men presented with LGV proctitis at the Erasmus Medical Center, Rotterdam, The Netherlands. We investigated a possible outbreak in a sexual network of men who have sex with men (MSM). METHODS After active case finding, a total of 15 men presented and were investigated. Serum antibody titers to Chlamydia trachomatis were determined. Urine and rectum specimens were analyzed by polymerase chain reaction (PCR) for the presence of C. trachomatis. C. trachomatis-positive specimens were genotyped to detect the specific C. trachomatis serovars. All subjects underwent routine STD screening. Sociodemographic, clinical, and endoscopic characteristics were evaluated. RESULTS Thirteen subjects had high immunoglobulin (Ig) G and IgA titers to C. trachomatis, suggesting an invasive infection. Rectal specimens of 12 subjects were PCR-positive for C. trachomatis. All urine specimens were negative. Genotyping revealed serovars L(2) (n=8) and L(1) (n=1). An ulcerative proctitis was found in all subjects obtaining sigmoidoscopy (n=9). Eleven of 13 subjects with an LGV diagnosis were seropositive for human immunodeficiency virus (HIV), 6 had another concomitant STD, and 1 had recently acquired a hepatitis C virus infection. Further sexual contacts were reported from The Netherlands, Germany, Belgium, the United Kingdom, and France. CONCLUSIONS We revealed an outbreak of LGV proctitis among MSM in The Netherlands. The ulcerous character favors transmission of HIV, other STDs, and blood-borne diseases. From a public health perspective, it seems important to increase the awareness of possible LGV in MSM with symptomatic proctitis.


Gastrointestinal Endoscopy | 1998

Coated self-expanding metal stents versus latex prostheses for esophagogastric cancer with special reference to prior radiation and chemotherapy: a controlled, prospective study

Peter D. Siersema; Wim C. J. Hop; Jan Dees; Hugo W. Tilanus; Mark van Blankenstein

BACKGROUND Self-expanding metal stents seem to be safer than conventional prostheses for palliation of malignant esophagogastric obstruction. However, recurrent dysphagia caused by tumor ingrowth in uncoated types remains a problem. In addition, prior radiation and/or chemotherapy may entail an increased risk of complications. METHODS Seventy-five patients with an esophagogastric carcinoma were randomly assigned to placement of a latex prosthesis under general anesthesia or a coated, self-expanding metal stent under sedation. At entry, patients were stratified for location of the tumor in the esophagus or cardia and for prior radiation and/or chemotherapy. RESULTS Technical success and improvement in dysphagia score were similar in both groups. Major complications were more frequent with latex prostheses (47%) than with metal stents (16%) (odds ratio 4.07: 95% CI [1.35, 12.50], p = 0.014). Recurrent dysphagia was not different between latex prostheses (26%) and metal stents (24%). Hospital stay was longer, on average, after placement of latex prostheses than metal stents (6.3 +/- 5.2 versus 4.3 +/- 2.3 days; p = 0.043). Only prior radiation and/or chemotherapy increased the risk of specific device-related complications with respect to the esophagus (12 of 28 [43%] versus 8 of 47 [17%]; odds ratio 3.66: 95% CI [1.24, 10.82], p = 0.029). CONCLUSIONS Coated, self-expanding metal stents are associated with fewer complications and shorter hospital stay as compared with latex prostheses, and prior radiation and/or chemotherapy increases the risk of device-related complications with respect to the esophagus.


Gut | 1989

Adenocarcinoma in Barrett's oesophagus: an overrated risk.

A H Van der Veen; Jan Dees; J D Blankensteijn; M. van Blankenstein

Barretts oesophagus is a risk factor for the development of oesophageal cancer and for this reason annual endoscopic surveillance has been proposed. In this retrospective study of all patients with Barretts oesophagus diagnosed in a 12 year period carcinoma had developed in only four patients. The incidence of oesophageal cancer in this series was one in 170 patient years, which means a 30-fold increase compared with the general population. The survival of patients with Barretts oesophagus was not different, however, from an age and sex matched control population. It is concluded that systematic endoscopic surveillance of patients with Barretts oesophagus is not indicated.


Gastrointestinal Endoscopy | 2004

Ingestion of acid and alkaline agents: outcome and prognostic value of early upper endoscopy ☆

Jan-Werner Poley; Ewout W. Steyerberg; Ernst J. Kuipers; Jan Dees; Rober Hartmans; Hugo W. Tilanus; Peter D. Siersema

BACKGROUND Ingestion of caustic substances often leads to severe morbidity and, frequently, death. This study compared complications and survival for patients who ingested an acidic substance, mainly glacial acetic acid, or an alkaline agent. METHODS Records for 179 patients hospitalized for ingestion of a caustic agent (85 acid [75 glacial acetic acid], 94 alkali) were reviewed. Mucosal injury, systemic and GI complications, and survival were scored. RESULTS Outcome was less favorable for patients who ingested acid compared with those who ingested alkali with respect to mucosal injury (median: grade 2 vs. grade 1; p=0.013), hospital stay (mean: 9.9 vs. 7.2 days; p=0.01), admittance to the intensive care unit (44% vs. 22%; p=0.002), systemic complications (24% vs. 3%; p < 0.001), perforation (6% vs. 0%; p=0.017), and mortality (14% vs. 2%; p=0.003). There was no difference in the development of strictures (acid, 15% vs. alkali, 17%). The grade of mucosal injury at endoscopy was the strongest predictive factor for the occurrence of systemic and GI complications and mortality (relative risk 9: 95% CI[3, 30]). Ten of 29 (34%) patients with strictures were treated by endoscopic dilation alone, whereas the others primarily (n=7) or secondarily (n=11) underwent surgery. One patient with an esophageal stricture died from systemic complications. CONCLUSIONS Acid ingestion, particularly glacial acetic acid, is associated with a higher frequency of complications and mortality rate than alkali ingestion. Early endoscopy probably is safe and provides important prognostic information. Endoscopic treatment of caustic-induced strictures is only moderately successful.


Scandinavian Journal of Gastroenterology | 2004

Oesophageal cancer incidence and mortality in patients with long-segment Barrett's Oesophagus after a mean follow-up of 12.7 years

Mariska Hage; Peter D. Siersema; H. van Dekken; Ewout W. Steyerberg; Jan Dees; Ernst J. Kuipers

Background: Data on cancer risk in patients with long-segment Barretts oesophagus (BO) from older studies are often difficult to interpret, since the definition of BO has evolved from an endoscopical to a histological diagnosis. In this work the diagnoses in the Rotterdam BO cohort on current standards was redefined to obtain more accurate data on cancer risk in patients who had not undergone standard endoscopic surveillance. In addition, it was determined which patient factors present at index endoscopy were associated with neoplastic progression in BO. Methods: The Rotterdam BO cohort comprises all patients with ≥3 cm BO, diagnosed at endoscopy between 1973 and 1984. In the present study, only patients with intestinal metaplasia were included (n = 105). Follow-up data were obtained by questionnaires and/or interviews with patients or treating physicians. A Kaplan-Meier analysis was used to estimate 20-year risks. Results: The mean length of the BO was 7.1 cm (range: 3-15 cm). Cancer in BO developed in 6/105 (6%) patients, and high-grade dysplasia (HGD) in 5/105 (5%) patients during 1329 patient-years of follow-up, which equals one cancer case per 221 patient-years and one HGD case per 266 patient-years. After a mean follow-up of 12.7 years, 72 (69%) patients had died; only 4 of them died of oesophageal cancer or its treatment. A longer length of BO was associated with an increased risk of progression to HGD or cancer (P < 0.02). Six of 24 patients who ever had low-grade dysplasia progressed to HGD or cancer 2-16 years after a diagnosis of BO. Conclusions: The annual risk of developing HGD or adenocarcinoma in patients with long-segment BO is 0.83%. Death due to adenocarcinoma is, however, uncommon, even in a cohort of patients with long-segment BO.


Gastrointestinal Endoscopy | 2013

Differences in proximal serrated polyp detection among endoscopists are associated with variability in withdrawal time

Thomas R. de Wijkerslooth; Esther M. Stoop; Patrick N M Bossuyt; Kristien M. Tytgat; Jan Dees; Elisabeth M. H. Mathus-Vliegen; Ernst J. Kuipers; Paul Fockens; Monique E. van Leerdam; Evelien Dekker

BACKGROUND Insufficient detection of proximal serrated polyps (PSP) might explain the occurrence of a proportion of interval carcinomas in colonoscopy surveillance programs. OBJECTIVE To compare PSP detection among endoscopists and to identify patient-related and endoscopist-related factors associated with PSP detection. DESIGN Prospective study in unselected patients. SETTING Colonoscopy screening program for colorectal cancer at two academic medical centers. PATIENTS Asymptomatic consecutive screening participants (aged 50-75 years). INTERVENTION Colonoscopies were performed by 5 experienced endoscopists. All detected polyps were removed. Multiple colonoscopy quality indicators were prospectively recorded. MAIN OUTCOME MEASUREMENTS We compared PSP detection among endoscopists by calculating odds ratios (OR) with logistic regression analysis. Logistic regression also was used to identify patient features and colonoscopy factors associated with PSP detection. RESULTS A total of 1354 patients underwent a complete screening colonoscopy: 1635 polyps were detected, of which 707 (43%) were adenomas and 685 (42%) were serrated polyps, including 215 PSPs. In 167 patients (12%) 1 or more PSPs were detected. The PSP detection rate differed significantly among endoscopists, ranging from 6% to 22% (P < .001). Longer withdrawal time (OR 1.12; 95% confidence interval, 1.10-1.16) was significantly associated with better PSP detection, whereas patient age, sex, and quality of bowel preparation were not. LIMITATIONS Limited number of highly experienced endoscopists. CONCLUSION The PSP detection rate differs among endoscopists. Longer withdrawal times are associated with better PSP detection, but patient features are not. ( CLINICAL TRIAL REGISTRATION NUMBER NTR1888.).


Clinical Gastroenterology and Hepatology | 2008

Desmoid Tumors in a Dutch Cohort of Patients With Familial Adenomatous Polyposis

Marry H. Nieuwenhuis; Wouter H. de Vos tot Nederveen Cappel; Akke Botma; Fokko M. Nagengast; Jan H. Kleibeuker; Elisabeth M.H. Mathus–Vliegen; Evelien Dekker; Jan Dees; Juul T. Wijnen; Hans F. A. Vasen

BACKGROUND & AIMS Desmoid tumors are a severe extracolonic manifestation in familial adenomatous polyposis (FAP). Identification of risk factors might be helpful in the management of FAP patients with such tumors. The aim of this study was to assess potential risk factors for the development of desmoids in a cohort of Dutch FAP patients. METHODS The medical records of 735 FAP patients were analyzed for the occurrence of desmoids. Relative risks and survival times were calculated to assess the influence of potential risk factors (female sex, family history, mutation site, abdominal surgery, and pregnancy) on desmoid development. RESULTS Desmoid tumors were identified in 66 of the 735 patients (9%). The cumulative risk of developing desmoids was 14%. No correlation was found between specific adenomatous polyposis coli mutation sites and desmoid development. Patients with a positive family history for desmoids had a significant increased risk to develop this tumor (30% vs 6.7%, P < .001). No association was found between female sex or pregnancy and desmoid development. Most desmoid patients (95%) had undergone previous abdominal surgery. In a substantial proportion of patients with an ileorectal anastomosis, it was impossible to convert the ileorectal anastomosis to an ileal pouch-anal anastomosis as a result of desmoid development. CONCLUSIONS A positive family history of desmoids is an evident risk factor for developing desmoids. Most desmoids develop after colectomy. No correlation was found between desmoids and the adenomatous polyposis coli gene mutation site, female sex, and pregnancy. Ileal pouch-anal anastomosis is the appropriate type of surgery in FAP patients with a positive family history for desmoids.


Gastrointestinal Endoscopy | 2000

A new design metal stent (Flamingo stent) for palliation of malignant dysphagia: a prospective study ☆ ☆☆ ★

Peter D. Siersema; Wim C. J. Hop; Mark van Blankenstein; Jan Dees

BACKGROUND Metal stents are not superior to conventional endoprostheses with respect to the incidence of recurrent dysphagia because of tumor ingrowth with uncovered stents and migration with their covered counterparts. To overcome these limitations, a partially covered (inside-out covering) metal stent with a conical shape and a varying braiding angle of the mesh along its length, the Flamingo stent, has been developed. METHODS From March 1997 to October 1997, 40 consecutive patients with dysphagia due to malignant tumors had either a small diameter (proximal/distal diameter 24/16 mm; n = 21) or a large diameter Flamingo stent (proximal/distal diameter 30/20 mm; n = 19) placed. RESULTS There was statistically significant improvement in dysphagia, but improvement was not greater with large diameter stents compared to small diameter stents (p = 0.21). Major complications (bleeding [4], perforation [1], fever [1] and fistula [1]) occurred in 7 (18%) patients. Large diameter stents tended to be associated with more major complications than small diameter stents (5 vs. 2; p = 0.07). Pain following stent placement was observed in 9 (22%) patients and occurred more frequently in those who had prior radiation and/or chemotherapy (p = 0.02). Recurrent dysphagia (mainly due to tumor overgrowth) occurred in 10 (25%) patients. CONCLUSIONS Flamingo stents are effective for palliation of malignant dysphagia, but the large diameter stent seems to be associated with more complications involving the esophagus than the small diameter stent. Because recurrent dysphagia is mainly due to tumor progression, further technical developments in stent design are needed.

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Ernst J. Kuipers

Erasmus University Rotterdam

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Peter D. Siersema

Erasmus University Rotterdam

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M. van Blankenstein

Erasmus University Rotterdam

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Jan-Werner Poley

Erasmus University Rotterdam

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Wim C. J. Hop

Erasmus University Rotterdam

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Esther M. Stoop

Erasmus University Rotterdam

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Jelle Haringsma

Erasmus University Rotterdam

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