Úvod: Gastrointestinální stromální tumory (GIST) jsou specifické neepitelové mezenchymální nádory gastrointestinálního traktu. Většina GISTů (95 %) vzniká v důsledku mutace genu transmembránového tyrozinkinázového proteinu (KIT), což je receptor pro růstový faktor. Tento receptor na svém povrchu exprimují nádorové buňky GISTu. Nejčastěji postiženými orgány bývají žaludek a tenké střevo, ale můžeme ho nalézt kdekoli v průběhu trávicí trubice a orgánů dutiny břišní. Klinická manifestace bývá různá a je dána lokalizací nádoru, jeho velikostí či vztahem k okolním orgánům. U resekabilních nádorů je indikováno primární chirurgické řešení s cílem R0 resekce. Cílená léčba imatinibem (kompetitivní inhibitor KIT receptoru) je určena pro pacienty s metastatickým onemocněním a dále jako adjuvantní léčba po operaci nebo v indikovaných případech jako neoadjuvantní terapie. Práce se snaží o přehledné zpracování komplexní terapie GIST s důrazem na postavení chirurgické léčby a upozorňuje na některá kontroverzní témata, např. roli resekčního výkonu u pacientů s metastatickým onemocněním nebo neoadjuvantní podání cílené biologické léčby. Závěr: I přes nezpochybnitelný úspěch biologické léčby má chirurgická léčba nezastupitelné místo v terapii tohoto onemocnění. Diagnosticko-terapeutický přístup k pacientům s GISTem musí být komplexní. Preskripční omezení biologické léčby přímo nutí směrovat tyto pacienty do specializovaných center, kde by s výhodou měla být prováděna i léčba chirurgická., Introduction: Gastrointestinal stromal tumors (GIST) are specific mesenchymal tumors of the gastrointestinal tract. Most of GISTs (95%) result from activating mutations in one of the receptor tyrosine kinase proteins (KIT). Tumor cells express this protein. GIST is most common in the stomach and small intestine, but may occur anywhere in the gastrointestinal tract and intra-abdominal soft tissues. The variety of its clinical presentations is related to localization of the tumor, its size and relationship to surrounding organs. Surgery is the first choice of treatment for patients with localized or potentially resectable tumors with the intention of R0 resection. Targeted therapy with imatinib (a selective inhibitor of the KIT protein) is the primary option for patients with metastatic GIST, as adjuvant treatment after surgery or neo-adjuvant therapy prior to surgery in indicated cases. This paper describes comprehensive therapy of GIST with an emphasis laid on the status of surgical treatment, and it highlights some controversial topics, e.g. the role of surgery for metastatic disease or neo-adjuvant targeted therapy. Conclusion: GIST is a relatively rare tumor most commonly affecting the stomach and small intestine. Surgical treatment is not replaceable in the treatment strategy of this disease. The diagnostic-therapeutic approach to patients with GIST must be comprehensive. Due to prescribing restrictions of biological therapies, these patients are inevitably directed to specialized centers where surgical treatment should also be preferably provided., and L. Fiala, R. Šefr, I. Kocáková, M. Pacal
Neoadjuvant concomitant chemoradiotherapy has become a standard treatment of locally advanced rectal adenocarcinomas (LARA). It leads to shrinkage of the tumor mass and subsequently to an increase in complete resections (R0 resections), increasing a feasibility of sphincter-sparing intervention avoiding colostomy. It is based on concurrent application of fluoropyrimidines (5-fluorouracil, capecitabine) and radiotherapy (45 - 50,4 Gy). It shows less acute toxicity and improves local control rate in comparison to adjuvant treatment. Unfortunately, neoadjuvant chemoradiotherapy is not beneficial for all patients. The treatment response ranges from a complete pathological remission (pCR, ypT0ypN0) to a resistance. It is reported that cca 15 percent of patients with advanced rectal cancer show pCR which is indicative of improved long-term prognosis. DESIGN: The following is a review of the significance of neoadjuvant concomitant chemoradiotherapy in the treatment algorithm of patients with LARA and summary of potentional clinical-pathological and molecular markers of response prediction to neoadjuvant therapy. The most important clinical studies concern serum tumor markers levels, clinical lymph node classification. The components of the carcinogenic pathways are explored, including oncogenes, tumor supressor genes, microsatellite instability (MSI) and potentional markers involved in apoptosis, angiogionesis, proliferation as well as metastasis and invasion, are reviewed. Finally, the role of specific enzymes associated with the metabolism of fluoropyrimidines are examined. CONCLUSIONS: No one marker has been consistently identified as clinically applicable. Studies designed to determine the potentional markers are hampered by various techniques as well as tumor heterogenity and recent scientific approach--studying individual molecular markers. Gene expression profiling analysis of multiple genes from the same tumor is becoming reality. We suppose that this assessment will lead in future in finding combination of markers for predicting prognosis and response to therapy in rectal cancer., Garajová Ingrid, Svoboda M., Slabý O., Kocáková L., Fabian P., Kocák I., Vyzula R., and Lit.: 71