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Contains fulltext : 171401.pdf (Publisher’s version ) (Closed access) INTRODUCTION: Liver metastases are common in patients with gastrointestinal stromal tumors (GIST). In the absence of randomized controlled clinical trials, the effectiveness of surgery as a treatment modality is unclear. This study identifies safety and outcome in a nationwide study of all patients who underwent resection of liver metastases from GIST. METHODS: Patients were included using the national registry of histo- and cytopathology (PALGA) of the Netherlands from 1999. Kaplan Meier survival analysis was used for calculating survival outcome. Univariate and multivariate regression analyses were carried out for the assessment of potential prognostic factors. RESULTS: A total of 48 patients (29 male, 19 female) with a median age of 58 (range 28-81) years were identified. Preoperative and postoperative tyrosine kinase inhibitor therapy was given to 30 (63%) and 36 (75%) patients, respectively. A minor liver resection was performed in 32 patients, 16 patients underwent major liver resection. Median follow-up was 27 (range 1-146) months. Median progression-free survival (PFS) was 28 (range 1-121) months. One-, three-, and five-year PFS was 93%, 67%, and 59% respectively. Median overall survival (OS) was 90 (range 1-146) months from surgery. The one-, three-, and five-year OS was 93%, 80%, and 76% respectively. R0 resection was the only independent significant prognostic factor for DFS and OS at multivariate analysis. CONCLUSION: Resection of liver metastases in GIST patients combined with imatinib may be associated with prolonged overall survival when a complete resection is achieved.

Background: The greater omentum is frequently involved in the course of gastrointestinal and ovarian tumors. Therefore, common practice in surgical treatment for especially gastric and ovarian cancer includes removal of the greater omentum. Paradoxically, many immune cells, such as macrophages that accumulate in so-called milky spots, reside within the omentum and are cytotoxic against tumor cells ex vivo. Consequently, omental macrophages might play an important role in killing tumor cells, and may hereby prevent development into local peritoneal recurrences. In the present study, we therefore evaluated the role of the omentum and the clinical relevance of omentectomy in minimal residual disease (MRD). Methods: Tumor cell dissemination patterns on the omentum in a rat model were examined using DiI-labelled CC531s tumor cells. Additionally, intra peritoneal (i.p.) tumor load was investigated in rats that underwent omentectomy or sham laparotomy followed by i.p. injection of CC531s cells on day 21, which represented MRD. Results: At 4 h post injection, tumor cells predominantly adhered on milky spots. Number of cells thereafter declined rapidly suggesting initial tumor killing functions in these specific immune aggregates. Despite initial reduction observed in milky spots, numbers of tumor cells however increased at fatty tissue stripes that border the omentum. This indicated proliferation at these locations, which corresponded to macroscopic observations of the omenta on day 21 after tumor cell injection. Omentectomy resulted in reduced intra-abdominal tumor load, which was completely attributable to the absence of the omentum, as tumor development did not differ on other sites. Even in the MRD group microscopic clusters of tumor cells located in the omentum eventually developed into macroscopic nodules.Conclusion: Since the ability of omental milky spots is, even in MRD, insufficient to prevent intra abdominal tumor outgrowth, omentectomy, which reduces tumor load, is recommended in surgical treatment of intra abdominal tumors that are prone to disseminate intraperitoneally.

Background Local peritoneal recurrence is a relatively common complication after intentionally curative surgery for colorectal cancer and has unfavourable prognosis. Methods This manuscript reviews the relevant experimental and clinical literature on surgical trauma and development of local recurrences, which was obtained by extensive search in the PubMed database. Results and conclusion Although surgery is required as the only option for treatment, operative trauma and subsequent wound healing promote development of local recurrences. Minimizing peritoneal trauma reduces local tumour outgrowth in animal models, but clinical trials have not been conclusive so far. Recognition of the increased susceptibility to tumour establishment in the early post-operative phase challenges the aim for further research, targeting at strategies that obstruct local tumour implantation or outgrowth and/or improve (local) anti-tumour response.

Aim: The objective was to evaluate whether contrast-enhanced magnetic resonance imaging (MRI) techniques used in a pre-operative assessment protocol for colorectal liver metastases are as accurate as spiral computer tomography during arterial portography (CTAP). Pre-operative accuracy and clinical consequences of MRI are described and compared with CTAP. Moreover, post-operative survival rate and tumour recurrence were studied.Methods: The study group comprised 84 patients which were possible candidates for a partial hepatectomy for colorectal liver metastases. Patients were pre-operatively evaluated by CT of the abdomen, CT of the thorax and spiral CTAP and ferumoxide-enhanced MRI was performed in routine way for all patients. Following this selection, 35 patients underwent a partial hepatectomy with curative intent. All patients were retrospectively evaluated.Results: Ferumoxide-enhanced MRI proved to be at least as accurate as spiral CTAP in 81% of patients. In nine patients (11%) spiral CTAP revealed more intrahepatic lesions than MRI; in only two patients (2%) did these foundings influenced the clinical decision. These patients were considered to have irresectable disease. In seven patients (8%) MRI detected more lesions than spiral CTAP and influenced the clinical decision in three patients (4%) and these did not undergo a laparotomy. The actuarial 3 year overall survival of operated patients was 41% and the actuarial 3 year disease-free survival was 19%.Conclusion: Evaluation of the clinical impact of a pre-operative assessment protocol extended with ferumoxide MRI techniques demonstrated that this non-invasive MRI technique is safe and at least as accurate as spiral CTAP. This MRI technique results in comparable clinical decisions and outcome after hepatectomy. We suggest that the performance of routine contrast-enhanced MRI should instead be used in the pre-operative evaluation of colorectal liver metastases. (C) 2002 Published by Elsevier Science Ltd.