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I D Nagtegaal

Publications and source records attributed to I D Nagtegaal.

11 recordsLinked to original sources
PubMed2006

Preoperative assessment of the circumferential margin in rectal cancer is more informative in treatment planning than the T stage.

Preventing local recurrence in rectal cancer means achieving a free circumferential resection margin (CRM) through an optimal combination of surgery, radiotherapy and chemotherapy. This requires a differentiation between primary resectable and locally advanced cancers. The T staging used, while being a powerful marker of prognosis, has two major downsides. First, accuracy of preoperative predictions of the T stage is unacceptably low. Second, a T3 tumor can be either primary resectable or locally advanced. A review of the literature was performed to establish the value of the CRM as the preferred preoperative staging classification, and to establish the feasibility of predicting the CRM using modern day, high-resolution imaging techniques. We advocate using the CRM as preoperative staging classification. Magnetic resonance imaging and multislice computed tomography offer an accurate pre-operative prediction of the CRM, and staging by means of predicted CRM offers the ideal combination of accuracy and clinical relevance.

Combined Modality Therapy↗
PubMed2005

Pathological quality assurance in gastro-intestinal cancer.

Quality assurance has become an integrated and important part of surgical pathology. Not only laboratory quality systems and quality control of pathology reporting have been introduced, also interdisciplinary quality systems are being developed. This review focuses on the different aspects of quality assurance that can nowadays be used in the daily practice of pathology management of gastrointestinal cancers, especially, gastric- and colorectal cancer. Own data are, especially, derived from the recently conducted clinical trial on pre-operative radiotherapy for rectal cancer and emphasize the importance of multidisciplinary approaches.

Clinical Trials as Topic↗
PubMed2004

Radiation induces different changes in expression profiles of normal rectal tissue compared with rectal carcinoma.

PURPOSE: Radiotherapy is a very effective adjuvant treatment for rectal cancer with little side effects. Its killing effect on tumor cells seems to be more profound than the effect on normal tissue. The molecular events caused by irradiation are mainly analyzed in in vitro and animal models; investigations on human material are rare. In the current study, we analyzed the effects of irradiation on gene expression in normal and tumor tissue of rectal cancer patients. METHODS AND MATERIALS: Normal and carcinoma tissue of patients from a randomized clinical trial of the benefits of preoperative radiotherapy were analyzed using the Affymetrix Human Cancer Gene Chip. Preoperative radiotherapy was given within 5 days prior to surgery. Results for normal tissue and tumor were compared to investigate the radiation-related differences between normal and tumor cells. We clustered the differentially expressed genes based on their functional annotation. Results were compared with immunohistochemical and literature data. RESULTS: The majority of the investigated cancer-related genes remained unchanged by irradiation (92% in tumor tissue and 93% in normal tissue). The differentially expressed genes varied between tumor and normal tissue except for maspin and IL-8. Both in tumor and normal tissue, differentially expressed genes were present related to cell signaling and cycle control, apoptosis and cell survival and tissue response and repair. However, the spectrum of affected genes was totally different. CONCLUSION: Pre-existing differences in gene expression between normal tissue and tumor tissue might explain the differences in their responses to radiation. This change in response may explain the clinical beneficial effect of radiotherapy on tumor cells (low local recurrence rate) and the less severe effects on normal tissue (minor side effects).

Apoptosis↗
PubMed2003

Radiotherapy does not compensate for positive resection margins in rectal cancer patients: report of a multicenter randomized trial.

PURPOSE: Circumferential resection margin (CRM) involvement is a prognostic factor for local recurrence in rectal cancer. In a randomized trial comparing preoperative radiotherapy (5 x 5 Gy), followed by total mesorectal excision (TME) with TME alone, we demonstrated the beneficial effect of short-term preoperative radiotherapy on local recurrences. Here we evaluate the effect of radiotherapy on local recurrence rates in patients with different CRM involvements. METHODS AND MATERIALS: Circumferential margins were defined as positive (< or =1 mm), narrow (1.1-2 mm), or wide (>2 mm). Postoperative radiotherapy was mandatory for surgery-only patients with a positive CRM, but was not always administered and enabled us to compare local recurrence rates for patients with or without postoperative radiotherapy. Furthermore, the effect of preoperative radiotherapy was assessed in the different margin groups. RESULTS: Of 120 patients in the surgery-only group with a positive CRM, 47% received postoperative radiotherapy. There was no difference in the local recurrence rate between the irradiated and nonirradiated patients (17.3% vs. 15.7%, p = 0.98). Preoperative radiotherapy was effective in patients with a narrow CRM (0% vs. 14.9%, p = 0.02) or wide CRM (0.9 vs. 5.8%, p < 0.0001), but not in patients with positive margins (9.3% vs. 16.4%, p = 0.08). CONCLUSION: Preoperative hypofractionated radiotherapy has a beneficial effect in patients with wide or narrow resection margins, but cannot compensate for microscopically irradical resections resulting in positive margins.

Adenocarcinoma↗
PubMed2002

The role of pathologists in the quality control of diagnosis and treatment of rectal cancer-an overview.

Pathological examination of the rectal cancer resection specimen has an increasingly important role in influencing decisions about clinical management. Standardisation of the examination procedures and reporting are necessary. To evaluate the relevant pathological factors, data from randomised clinical trials with adequate follow-up are necessary. From a recently closed trial on the treatment of rectal cancer (preoperative radiotherapy or total mesorectal excision (TME) surgery alone?), the pathological data were used to evaluate the importance of pathological factors, like circumferential margin and tumour, lymph nodes, metastasis (TNM) stage. Furthermore, it was possible to evaluate the surgical procedures and correlate these findings to clinically relevant endpoints. In this review, we describe the standard evaluation of a rectal cancer specimen with special attention to preoperative irradiated specimens.

Humans↗
PubMed2001

Preoperative radiotherapy combined with total mesorectal excision for resectable rectal cancer.

BACKGROUND: Short-term preoperative radiotherapy and total mesorectal excision have each been shown to improve local control of disease in patients with resectable rectal cancer. We conducted a multicenter, randomized trial to determine whether the addition of preoperative radiotherapy increases the benefit of total mesorectal excision. METHODS: We randomly assigned 1861 patients with resectable rectal cancer either to preoperative radiotherapy (5 Gy on each of five days) followed by total mesorectal excision (924 patients) or to total mesorectal excision alone (937 patients). The trial was conducted with the use of standardization and quality-control measures to ensure the consistency of the radiotherapy, surgery, and pathological techniques. RESULTS: Of the 1861 patients randomly assigned to one of the two treatment groups, 1805 were eligible to participate. The overall rate of survival at two years among the eligible patients was 82.0 percent in the group assigned to both radiotherapy and surgery and 81.8 percent in the group assigned to surgery alone (P=0.84). Among the 1748 patients who underwent a macroscopically complete local resection, the rate of local recurrence at two years was 5.3 percent. The rate of local recurrence at two years was 2.4 percent in the radiotherapy-plus-surgery group and 8.2 percent in the surgery-only group (P<0.001). CONCLUSIONS: Short-term preoperative radiotherapy reduces the risk of local recurrence in patients with rectal cancer who undergo a standardized total mesorectal excision.

Adenocarcinoma↗
PubMed2001

Local and distant recurrences in rectal cancer patients are predicted by the nonspecific immune response; specific immune response has only a systemic effect--a histopathological and immunohistochemical study.

BACKGROUND: Invasion and metastasis is a complex process governed by the interaction of genetically altered tumor cells and the immunological and inflammatory host response. Specific T-cells directed against tumor cells and the nonspecific inflammatory reaction due to tissue damage, cooperate against invasive tumor cells in order to prevent recurrences. Data concerning involvement of individual cell types are readily available but little is known about the coordinate interactions between both forms of immune response. PATIENTS AND METHODS: The presence of inflammatory infiltrate and eosinophils was determined in 1530 patients with rectal adenocarcinoma from a multicenter trial. We selected 160 patients to analyze this inflammatory infiltrate in more detail using immunohistochemistry. The association with the development of local and distant relapses was determined using univariate and multivariate log rank testing. RESULTS: Patients with an extensive inflammatory infiltrate around the tumor had lower recurrence rates (3.4% versus 6.9%, p = 0.03), showing the importance of host response against tumor cells. In particular, peritumoral mast cells prevent local and distant recurrence (44% versus 15%, p = 0.007 and 86% versus 21%, p < 0.0001, respectively), with improved survival as a consequence. The presence of intratumoral T-cells had independent prognostic value for the occurrence of distant metastases (32% versus 76%, p < 0.0001). CONCLUSIONS: We showed that next to properties of tumor cells, the amount and type of inflammation is also relevant in the control of rectal cancer. Knowledge of the factors involved may lead to new approaches in the management of rectal cancer.

Adenocarcinoma↗
PubMed2001

No downstaging after short-term preoperative radiotherapy in rectal cancer patients.

PURPOSE: In retrospective studies, total mesorectal excision (TME) surgery has been demonstrated to result in a reduction in the number of local recurrences of rectal cancer. Reports on improved local control after preoperative, hypofractionated radiotherapy have led to the introduction of a randomized multicenter trial to evaluate the effect of TME surgery with and without preoperative radiotherapy. Treatment with preoperative radiotherapy might have an effect on the pathologic characteristics that determine staging of rectal cancer. We investigated the occurrence of downstaging in rectal cancer patients treated with and without preoperative radiotherapy. PATIENTS AND METHODS: We analyzed the differences in tumor size, number of examined lymph nodes, tumor-node-metastasis stage, and histopathologic features in 1,321 patients entered onto a randomized trial. The trial compared preoperative radiotherapy (5 x 5 Gy) followed by TME surgery with TME surgery alone. Patients who had an interval of more than 10 days between the start of radiotherapy and surgery were excluded from analysis. RESULTS: Differences were observed in tumor size (P <.001) and total number of examined lymph nodes (P <.001). No difference in tumor or node classification was detected. The irradiated group demonstrated more poorly differentiated tumors as well as more mucinous tumors. CONCLUSION: In rectal cancer patients, short-term, preoperative radiotherapy with 5 x 5 Gy does not lead to downstaging if the interval between the start of radiotherapy and surgery does not exceed 10 days.

Adult↗
PubMed2000

Pathology data in the central databases of multicenter randomized trials need to be based on pathology reports and controlled by trained quality managers.

PURPOSE: Randomized multicenter trials form the basis of health care development. Regarding cancer research, pathology data are crucial. To maintain the quality of these trials, the auditing of subsequent processes is necessary. The aim of the present study was to examine the completeness and accuracy of data obtained from a special-purpose standardized pathology form compared with the data available through traditional hospital pathology reports. PATIENTS AND METHODS: A retrospective comparison of pathology data case record forms with hospital pathology reports was performed using the data from 300 patients with primary rectal cancer. All of these patients had been included in a large multicenter trial in the Netherlands. Three independent audits were carried out. Special attention was given to the accuracy of parameters, which are important for prognosis and treatment decisions. Furthermore, various factors that possibly influence the occurrence of errors were investigated. RESULTS: Quality control of the pathology data revealed a high accuracy of 86.5% of all data items. However, only one third of the forms were complete and correct. Missing values were most prominent in the number of lymph nodes examined, whereas most errors were made in relation to the circumferential margin. Trained review pathologists made fewer major errors. Discrepancies were detected in all control rounds. CONCLUSION: Successive rounds of quality control are required for accuracy and completeness of pathology data in multicenter trials. In addition to the special-purpose pathology forms, original pathology reports have to be collected, and the data should also be controlled by a trained pathology quality manager.

Databases, Factual↗
PubMed1999

Mesalazine-induced apoptosis of colorectal cancer: on the verge of a new chemopreventive era?

BACKGROUND: It is an accepted fact that non-steroidal anti-inflammatory drugs (NSAIDs) are potent inhibitors of colorectal carcinogenesis. However, the major disadvantages of NSAIDs are gastrointestinal and renal toxicity. We conducted a prospective pilot study on the effects of the safe salicylic acid derivative, mesalazine, on apoptosis and proliferation of tumour cells and on normal tissue in colorectal cancer patients. METHODS: Patients with colorectal cancer were asked to take mesalazine enemas for 14 days. Biopsies from malignant and normal tissue were taken prior to and after this treatment. Apoptosis was scored on haematoxylin/eosin-stained tissue sections, and cell proliferation was assessed by the proliferation marker Ki-67. RESULTS: Ten out of 14 patients completed the study. The apoptotic score increased significantly in the tumour samples (pre-treatment 14.6 +/- 1.3 vs. post-treatment 19.4 +/- 0.8; P < 0.03). The apoptotic index in the normal mucosa was unchanged (pre-treatment 3.1 +/- 0.4 vs. post-treatment 2.9 +/- 0.3; N.S.). The cell proliferation in malignant tissue, according to the Ki-67 score, was hardly affected by mesalazine (pre-treatment 522 +/- 38 vs. post-treatment 493 +/- 39; N.S.). There was no effect on the Ki-67 index of normal mucosa (pre-treatment 24.2 +/- 2.0 vs. post-treatment 28.3 +/- 2.0; N.S.). CONCLUSIONS: This pilot study conducted in patients with colorectal cancer clearly shows that mesalazine selectively induces apoptosis of tumour cells. On the basis of these findings, which need to be confirmed in larger studies, it may be speculated that 5-ASA could be useful in the chemoprevention of colorectal cancer.

Aged↗