Volume 74 - 2011 - Fasc.4 - Symposium
Vascular Invasion, Perineural Invasion, and Tumour Budding : Predictors of Outcome in Colorectal Cancer
Tumour stage reflected by the AJCC/UICC TNM system is cur- rently regarded as the most powerful prognostic parameter in patients with colorectal cancer. However, additional histopatholog- ical markers are required to improve clinical decision-making with respect to follow-up scheduling and administration of adjuvant therapy. In this review we summarize the available literature regarding the prognostic impact of venous and lymphatic invasion, perineural invasion and tumour budding in colorectal cancer. Special emphasis was placed on patients with AJCC/UICC stage II disease, the risk of lymph node metastasis in early cancer and the prediction of local recurrence in rectal cancer. For each of the markers, the different methods of evaluation, implications result- ing from different definitions used in previous studies as well as future perspectives are discussed in detail. (Acta gastroenterol. belg., 2011, 74, 516-529).
The Role of PET in Predicting Response to Chemotherapy in oesophago-gastric Cancer
Treatment options for oesophago-gastric cancers reach from limited resection to multimodality treatment. An accurate clinical assessment and prognostic information are needed for selecting the most appropriate treatment approach. Positron emission tomogra- phy (PET) in combination with computed tomography (CT) in a hybrid imaging modality may ameliorate the staging accuracy and add prognostic information. Experiences from specialised centers indicate that PET also may aid to estimate and predict response to preoperative chemotherapy and chemoradiation. This article reca- pitulates the value of PET in the staging and multidisciplinary care of oesophago-gastric cancer. At this stage, it remains unclear if the prognosis of patients can be improved by implementing PET in the management of this disease. Prospective multicenter studies should be performed to validate metabolic cut-off values and to proof the benefit of PET-guided treatment decisions. (Acta gastroenterol. belg., 2011, 74, 530-535).
Cajal beyond the gut : interstitial cells in the urinary system - towards general regulatory mechanisms of smooth muscle contractility ?
Interstitial cells of Cajal (ICC), similar to GI pacemakers have been identified throughout the urinary system. Although each part of the system serves a different function, ranging from peristalsis of the ureters, storage of urine by the bladder, and a sphincteric action by the urethra, they share a common mechanism in being able to generate phasic myogenic contractions. Even the urethra, often considered to be a 'tonic' smooth muscle, achieves an appar- ently sustained contraction by averaging numerous small asyn- chronous 'phasic' contractions. This activity can occur in the absence of any neural input, implying the presence of an intrinsic pacemaker. Intracellular microelectrode recordings from urethral muscle strips reveal electrical slow waves similar to those of the GI tract. To study this further, we isolated single cells from rabbit ure- thra and found not only smooth muscle cells (SMC), but a second cell type comprising ~10% of the total. The latter cells were branched and non-contractile and closely resembled intestinal ICC. Electrophyiological studies revealed that, while the isolated smooth muscle cells were electrically quiescent, the 'ICC' fired electrical slow waves similar to those observed in the whole tissue. The basis of this difference was the presence of a large pacemaker current involving the activation of calcium-activated Cl- channels by spontaneous intracellular Ca2+ waves. These, in turn, have been shown to be modulated by neurotransmitters such as nitric oxide, noradrenaline and ATP, thus providing a possible mechanism whereby neural regulation of the urethra, as well as spontaneous tone, may be mediated via ICC. (Acta gastroenterol. belg., 2011, 74, 536-542).
How to prevent post-ERCP pancreatitis ?
The incidence of post-ERCP pancreatitis (PEP) has remained constant since 30 years. During the last 10 years, large progresses have been made in the knowledge of (i) factors that predispose to PEP and (ii) measures that are effective to prevent PEP. Many of these measures have not yet been widely implemented. Complete recommendations for PEP prophylaxis are summarized in the review. For high-risk ERCPs, including ampullectomy, pancreatic sphincterotomy, precut biliary sphincterotomy, known or suspect- ed sphincter of Oddi dysfunction, pancreatic guidewire-assisted biliary cannulation and endoscopic balloon sphincteroplasty, pro- phylactic pancreatic stent placement should be considered. For low-risk ERCPs, periprocedure rectal administration of NSAID is recommended. Prophylactic pancreatic stenting should be investi- gated in terms of education of endoscopists for insertion tech- niques, ease of stent insertion, reliability of spontaneous stent elimination and safety (demonstration of the absence of induced pancreatic changes). (Acta gastroenterol. belg., 2011, 74, 543-547).
Early versus late immune mediated inflammatory diseases
Immune mediated inflammatory diseases (IMIDs) are life long conditions that cause substantial morbidity and disability. Though increasingly common and intensely studied, the cellular and molec- ular mechanisms underlying their pathogenesis are still unclear. Despite this incomplete knowledge, it is becoming increasingly evi- dent that IMIDs evolve over time, not only from a clinical perspec- tive but also a pathophysiological one. Evidence is accumulating that the events responsible for inflammation and damage in the target organs are not necessarily the same during the evolution of the IMID, and that the immune response evolves in parallel with the clinical manifestations. This has crucial implications for thera- py because immunomodulatory interventions aimed at early path- ogenic events may no longer be effective when these events have changed due to a different composition of the immune response. Therefore, it is crucial to better understand why and how the IMID associated immune abnormalities evolve over time, so that time- dependent therapies may be rationally implemented for an improved clinical outcome. (Acta gastroenterol. belg., 2011, 74, 548- 552).
Transjugular intrahepatic portosystemic shunt - current status in 2011
This article overviews principles of portal hypertension and the role of implantation of a transjugular intrahepatic postosystemic shunt (TIPS) in its management. Since TIPS is available for over 30 years, technical achievements have been made and knowledge about indications, contraindications and patient selection has been improved. Recent studies and guidelines may lead to an increase in TIPS implantation rates. This review aims to commemorate the merits and demerits of TIPS in current clinical practice. (Acta gastroenterol. belg., 2011, 74, 553-559).