Gastrointestinal Stromal Tumours of the Rectum - Evaluating the National Registry Data with Respect to its Use in Clinical Practice.

BACKGROUND: Gastrointestinal stromal tumours (GIST) are rare malignant mesenchymal tumours with an incidence of 1 in 100,000. They represent only 5% of gastrointestinal tumours. The GISTs are mainly located in the stomach (60-70%) and in the rectum in < 5% of cases. In the case of localized, resectable tumours, the treatment is surgical resection. Depending on the size and localization of the tumour in the rectum, either a local excision, rectal resection with anastomosis, or abdominoperitoneal amputation with permanent stoma can be performed. In contrast to carcinomas, the metastasis of GISTs into lymph nodes is rare; therefore, from an oncological point of view, lymphadenectomy in the form of mesorectal excision is not required. Neoadjuvant treatment using tyrosine-kinase inhibitors (TKI) is recommended for tumours larger than 5 cm and in case of tumours infiltrating surrounding organs or sphincters in order to achieve complete resectability, less mutilating and continent procedure. In GISTs with a positive resection line, re-resection can be attempted. Adjuvant TKI therapy can be considered in cases of CD117 positivity and after resections of GISTs with medium and high-risk malignant behaviour. The TKI treatment is also indicated in cases of unresectable and metastatic GISTs. METHODS: Data obtained from the GIST registry by the 1st January 2017, when 10 centres in the Czech Republic were contributing to the registry, were analysed. RESULTS: We analysed 1,095 patients out of which 45 (4.1%) had GIST localized in the rectum. The average age of the patients was 60 years. There were significantly more males (68.9%; p = 0.0007) and symptomatic patients (62.2%; p = 0.034). In total, 82% of the patients underwent surgery. Local excision was performed in 37.8%, resection of the rectum with anastomosis in 29.7%, and Miles operation in 29.7%. In the cohort, most tumours were 2-5 cm in size and almost half of the tumours presented a high risk of malignant behaviour. Systemic treatment was reported in 73% of patients. A complete remission was achieved in 80% of patients with GIST of the rectum. The median survival rate was 11.3 years and the 5-year survival rate is 90.6%. CONCLUSION: Despite the success of TKI treatment, the only potentially curative method of rectal GISTs is a surgical R0 resection. Given the relatively rare frequency of these tumours, proper diagnosis and treatment is demanding. Therefore, these patients should be preferably treated in specialised centres. This work was supported by grant MH CZ - RVO (FNBr, 65269705).  The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 19. 12. 2018 Accepted: 2. 2. 2019.

Long term experience of patients with unresectable or metastatic KIT positive gastrointestinal stromal tumours.

A retrospective analysis of consecutive patients (183 in total, of which 105 were males and 78 females) with gastrointestinal stromal tumour (GIST) was performed. The mean age was 61 years, median age 64 years. The most frequent localization of the tumour was stomach in 74 patients (40.4 %) and the small intestine in 46 patients (25.1 %). Two or more different synchronous or metachronous cancers occurred in 34 (18.6 %) patients with histologically confirmed GIST. Ninety-six patients were treated with imatinib mesylate in palliative setting during the course of their disease. The therapy was finished in 60 patients and 36 patients have been treated so far. The median progression-free survival reached 32.9 months in the group of 96 patients treated with imatinib. The median overall survival in the group of 96 patients treated for metastatic disease reached 77 months. Two-year and 5-year survival was 85.2 % and 63.1 %, respectively. The second-line therapy with sunitinib malate was administered in 37 patients, of which 31 finished and 6 continued in the therapy. The median progression free survival and median survival since the sunitinib therapy initiation reached 8.4 and 22.1 months, respectively (Tab. 2, Fig. 2, Ref. 16).

[Registry of neuroendocrine tumors (NET) in Czech Republic after three years of data collection]. / Registr neuroendokrinních nádoru (NET) v CR po trech letech sberu dat.

BACKGROUND: Neuroendocrine tumors are traditionally considered to be "rare" diseases. On contrary, the prevalence of neuroendocrine tumors is high. Therefore, the diagnostics, treatment and follow-up of neuroendocrine tumors are subjected to an evolving interest. There are various specifics of neuroendocrine tumors requiring an appropriate feedback of each intervention i.e. data collection and central data evaluation. The "Cooperative Group for Neuroendocrine Tumors" (KSPNN) has been conducting a nationwide neuroendocrine tumors registry since June 2009. The first data summary after three years is aimed at evaluation of feasibility and data utility. MATERIAL AND METHODS: The anonymous data on diagnostics, therapy and follow up of patients with neuroendocrine tumors of any primary site are collected in the registry. The contribution is conditioned by morphologically proven diagnosis according to the current WHO 2010 classification, in earlier cases WHO 2000 classification. The registry is operated by the Institute of Biostatistics and Analyses, Masaryk University (Brno). The initial analysis includes data from June 2009 to October 2012. RESULTS: Data of a substantial share of neuroendocrine tumor carriers have been collected -  742 subjects with a valid record, i.e. about 14% of presumed prevalence. Moreover, the registry covers nearly one fourth of incidence in the period 2009- 2011. The morphological diagnoses with the sign of nonspecific "neuroendocrine tumors" comprise the majority of records (75%); the most frequent is "carcinoid tumor neuroendocrine tumors". This results in a clear requirement for more detailed specifications of morphology as well as separation of small cell (neuroendocrine) carcinoma possessing principal bio-logic differences to neuroendocrine tumors itself. There is an apparent polarity of recorded clinical stages. Both stage I and stage IV comprise 30% of the records. This result is presumably related to how the diagnosis is established, either early and incidentally in initial stage or late with a developed endocrine symptomatology, in advanced stage. There is an evident selection bias. The treatment data reflect current trends, dominance of surgical therapy including reasonable cytoreductive surgery, vast use of somatostatine analogues in advanced disease and persistent position of chemotherapy for high grade tumors. The distribution of treatment modalities in the records documents a certain adherence to international treatment standards (ENETS, ESMO, NCCN). CONCLUSION: The dynamics of data contributions confirm feasibility of data collection in the registry. The registry reveals a clear requirement for more detailed analyses of biopsies and more detailed disease morphology classification. In the near future, the registry is aimed to maintain the increasing volume of collected data and to cover the majority of neuroendocrine tumors incidence.