Cyclooxygenases and Prostaglandins in Tumor Immunology and Microenvironment of Gastrointestinal Cancer.

Chronic inflammation is a known risk factor for gastrointestinal cancer. The evidence that nonsteroidal anti-inflammatory drugs suppress the incidence, growth, and metastasis of gastrointestinal cancer supports the concept that a nonsteroidal anti-inflammatory drug target, cyclooxygenase, and its downstream bioactive lipid products may provide one of the links between inflammation and cancer. Preclinical studies have demonstrated that the cyclooxygenase-2-prostaglandin E2 pathway can promote gastrointestinal cancer development. Although the role of this pathway in cancer has been investigated extensively for 2 decades, only recent studies have described its effects on host defenses against transformed epithelial cells. Overcoming tumor-immune evasion remains one of the major challenges in cancer immunotherapy. This review summarizes the impacts of the cyclooxygenase-2-prostaglandin E2 pathway on gastrointestinal cancer development. Our focus was to highlight recent advances in our understanding of how this pathway induces tumor immune evasion.

Current management of succinate dehydrogenase-deficient gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are increasingly recognized as having diverse biology. With the development of tyrosine kinase inhibitors molecularly matched to oncogenic KIT and PDGFRA mutations, GISTs have become a quintessential model for precision oncology. However, about 5-10% of GIST lack these driver mutations and are deficient in succinate dehydrogenase (SDH), an enzyme that converts succinate to fumarate. SDH deficiency leads to accumulation of succinate, an oncometabolite that promotes tumorigenesis. SDH-deficient GISTs are clinically unique in that they generally affect younger patients and are associated with GIST-paraganglioma hereditary syndrome, also known as Carney-Stratakis Syndrome. SDH-deficient GISTs are generally resistant to tyrosine-kinase inhibitors, the standard treatment for advanced or metastatic GIST. Thus, surgical resection is the mainstay of treatment for localized disease, but recurrence is common. Clinical trials are currently underway investigating systemic agents for treatment of advanced SDH-deficient GIST. However, further studies are warranted to improve our understanding of SDH-deficient GIST disease biology, natural history, surgical approaches, and novel therapeutics.

Clinical Association between Phospho-AKT Expression with Clinicopathological Characteristics of Gastrointestinal Cancer Patients: A Meta-Analysis.

Deregulation of AKT (protein kinase B) is frequently observed in human malignancies including gastrointestinal (GI) cancers. Here we have reviewed the association between AKT phosphorylation (activation) and clinical and pathological characteristics of patients with GI cancer. Articles in the EMBASE, PubMed, Cochrane Library, and Web of Science databases were searched up to July 2018. Eighteen studies comprising 1,698 patients with 5 different cancer types were included in the meta-analysis. In the pooled analysis, AKT phosphorylation was positively correlated with tumor size (r = 0.14, 95% CI: 0.06-0.22; P < 0.001), tumor grade (r = 0.08, 95% CI: 0.02-0.14; P < 0.009), tumor stage (r = 0.19, 95% CI: 0.13-0.24; P < 0.001), lymph node status (r = 0.18, 95% CI: 0.09-0.25; P < 0.001) and the presence of distant metastasis (r = 0.14, 95% CI: 0.06-0.22; P < 0.001) in the patients with GI cancer. These findings support the potential clinical value of AKT as a prognostic marker and therapeutic target in patients with GI carcinomas.

New drugs in gastrointestinal stromal tumors.

PURPOSE OF REVIEW: Tyrosine kinase inhibitors (TKIs) are the backbone for advanced gastrointestinal stromal tumor (GIST) treatment. The increasing knowledge concerning the structure and the changing conformational status because of some mutations in KIT and PDGFRα, allowed the development of new efficient compounds, with the main goal to overcome resistance in GIST. This review summarizes the latest developments in the treatment of GIST patients. RECENT FINDINGS: Amongst the several TKIs currently being studied in GIST, ripretinib, avapritinib and crenolanib had shown promising potent activity in preclinical studies and clinical trials. Ripretinib is a type II inhibitor that exerts its main action in the switch pocket of the activation loop, by mimicking the inhibition exerted by the regulatory region in this domain. Ripretinib is considered the new standard in the fourth line in advanced GIST. Avapritinib is a type I inhibitor synthesized to exerts its activity in the active conformation of the activation loop of KIT and PDFGRα. The relevant activity reported with avapritinib in patients carrying the D842 v mutation represents, for first time, an active therapeutic option in this resistant mutant. Crenolanib is a type I selective inhibitor of PDGFRα-resistant mutants, mainly D842 V, which is currently under clinical trial. SUMMARY: New potent TKIs are being approved, adding value to the already three registered drugs. Other agents, such as MEK inhibitors, immunotherapy and TRK-targeted therapy are potential new options in specific subsets of GIST patients.

Endoplasmic Reticulum Calcium Pumps and Tumor Cell Differentiation.

Endoplasmic reticulum (ER) calcium homeostasis plays an essential role in cellular calcium signaling, intra-ER protein chaperoning and maturation, as well as in the interaction of the ER with other organelles. Calcium is accumulated in the ER by sarco/endoplasmic reticulum calcium ATPases (SERCA enzymes) that generate by active, ATP-dependent transport, a several thousand-fold calcium ion concentration gradient between the cytosol (low nanomolar) and the ER lumen (high micromolar). SERCA enzymes are coded by three genes that by alternative splicing give rise to several isoforms, which can display isoform-specific calcium transport characteristics. SERCA expression levels and isoenzyme composition vary according to cell type, and this constitutes a mechanism whereby ER calcium homeostasis is adapted to the signaling and metabolic needs of the cell, depending on its phenotype, its state of activation and differentiation. As reviewed here, in several normal epithelial cell types including bronchial, mammary, gastric, colonic and choroid plexus epithelium, as well as in mature cells of hematopoietic origin such as pumps are simultaneously expressed, whereas in corresponding tumors and leukemias SERCA3 expression is selectively down-regulated. SERCA3 expression is restored during the pharmacologically induced differentiation of various cancer and leukemia cell types. SERCA3 is a useful marker for the study of cell differentiation, and the loss of SERCA3 expression constitutes a previously unrecognized example of the remodeling of calcium homeostasis in tumors.

Prognostic utility and clinical significance of lysyl oxidase-like 2 protein expression in digestive system cancers.

Lysyl oxidase-like 2 (LOXL2) participates in the occurrence and development of digestive system cancers (DSCs). The aim of this study was to determine whether LOXL2 protein could serve as a prognostic biomarker in patients with DSCs. Relevant studies published before October 1, 2018 were identified from a comprehensive literature review in PubMed, Web of Science, and Embase. This meta-analysis was conducted via STATA/SE 14.1 software. Finally, a total of 12 publications and 6 different kinds of DSCs were identified. Meta-analysis indicated that increased expression of LOXL2 protein was significantly correlated with reduced overall survival (hazard ratios [HR]: 1.52; 95% confidence interval [CI]: 1.32-1.72) and worse progression-free survival/disease-free survival (HR: 2.15; 95% CI: 1.48-2.83) in cases with DSCs. In addition, clinicopathological parameters, including tumor invasion, lymph node metastasis, distant metastasis, and clinical stage were significantly related to LOXL2 protein expression in DSCs. High LOXL2 protein expression is significantly associated with worse clinical outcomes in DSCs and its expression level may represent a candidate prognostic biomarker in these cancers.

Complementary activity of tyrosine kinase inhibitors against secondary kit mutations in imatinib-resistant gastrointestinal stromal tumours.

BACKGROUND: Most patients with KIT-mutant gastrointestinal stromal tumours (GISTs) benefit from imatinib, but treatment resistance results from outgrowth of heterogeneous subclones with KIT secondary mutations. Once resistance emerges, targeting KIT with tyrosine kinase inhibitors (TKIs) sunitinib and regorafenib provides clinical benefit, albeit of limited duration. METHODS: We systematically explored GIST resistance mechanisms to KIT-inhibitor TKIs that are either approved or under investigation in clinical trials: the studies draw upon GIST models and clinical trial correlative science. We subsequently modelled in vitro a rapid TKI alternation approach against subclonal heterogeneity. RESULTS: Each of the KIT-inhibitor TKIs targets effectively only a subset of KIT secondary mutations in GIST. Regorafenib and sunitinib have complementary activity in that regorafenib primarily inhibits imatinib-resistance mutations in the activation loop, whereas sunitinib inhibits imatinib-resistance mutations in the ATP-binding pocket. We find that rapid alternation of sunitinib and regorafenib suppresses growth of polyclonal imatinib-resistant GIST more effectively than either agent as monotherapy. CONCLUSIONS: Our data highlight that heterogeneity of KIT secondary mutations is the main mechanism of tumour progression to KIT inhibitors in imatinib-resistant GIST patients. Therapeutic combinations of TKIs with complementary activity against resistant mutations may be useful to suppress growth of polyclonal imatinib-resistance in GIST.

Enrichment of HER2 Amplification in Brain Metastases from Primary Gastrointestinal Malignancies.

BACKGROUND: In nongastric gastrointestinal (GI) cancers, HER2-positive (HER2+) disease is not common. In breast cancer, HER2 status is associated with increased risk of brain metastases and response to HER2-targeted therapy. The purpose of this project was to compare HER2 status in GI cancer brain metastases versus matched prior sites of disease in order to determine if HER2+ disease is more common intracranially. MATERIALS AND METHODS: We identified 28 patients with GI cancer who had craniotomy for brain metastases between 1999 and 2017 with intracranial metastatic tissue available at Massachusetts General Hospital. Twenty-four patients also had tissue from a prior site of disease. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) for HER2 were performed on all samples. A tumor was defined as HER2+ if it had 3+ staining by IHC or amplification by FISH. RESULTS: A prior site of disease (including intracranial metastases) was HER2+ for 13% of evaluable patients: 3 of 11 patients with colorectal cancer and no patients with esophageal or pancreatic cancer. The most recent brain metastases were HER2+ for 32% of patients: 2 of 3 esophageal squamous cell carcinomas, 3 of 10 esophageal adenocarcinomas (ACs), 3 of 14 colorectal ACs, and 1 of 1 pancreatic AC. Only 37.5% of patients with HER2+ brain metastasis had concordant HER2+ prior tissue (κ = 0.38, p = .017). CONCLUSION: In this cohort of patients with GI cancer with brain metastases, HER2+ status was more common intracranially compared with prior sites of disease. These findings suggest that testing HER2 in patients with GI cancer with brain metastases may lead to additional therapeutic options, regardless of HER2 status in previously examined tissue. IMPLICATIONS FOR PRACTICE: HER2 amplification is a well-known driver of oncogenesis in breast cancer, with associated increased risk of brain metastases and response to HER2-directed therapy. In nongastric gastrointestinal (GI) cancers, HER2 amplification is not common and consequently is infrequently tested. The current study shows that brain metastases in patients with GI primary malignancies have a relatively high likelihood of being HER2 positive despite HER2 amplification or overexpression being less commonly found in matched tissue from prior sites of disease. This suggests that regardless of prior molecular testing, patients with GI cancer with brain metastases who have tissue available are likely to benefit from HER2 assessment to identify potential novel therapeutic options.

New therapeutic agents in gastrointestinal stromal tumours.

PURPOSE OF REVIEW: The aim of this study was to provide an update on the most recent developments regarding systemic treatments in the various molecular subtypes of gastrointestinal stromal tumour (GIST). RECENT FINDINGS: Several novel direct inhibitors of KIT and PDGFRA have entered the advanced clinical development in later treatment lines based on promising early clinical trial experience. Both avapritinib and ripretinib are more potent and more specific against various KIT and PDGFRA mutations. For patients with PDGFRA D842V mutations, the next generation of drugs may become the first active treatment options.Comprehensive molecular testing of KIT/PDGFRA-wildtype GIST may unmask clinically relevant targets, including NTRK fusions. SUMMARY: The treatment landscape in GIST is expected to undergo a profound transformation with more potent drugs currently in late-stage clinical development.

A phase Ib study of BGJ398, a pan-FGFR kinase inhibitor in combination with imatinib in patients with advanced gastrointestinal stromal tumor.

Background Preclinical studies suggest that imatinib resistance in gastrointestinal stromal tumor (GIST) can be mediated by MAP-kinase activation via fibroblast growth factor (FGF) signaling. In FGF stimulated GIST cell lines, BGJ398, a pan-FGFR kinase inhibitor in combination with imatinib, was cytotoxic and superior to imatinib therapy alone. In FGF-dependent GIST, the combination of BGJ398 and imatinib may provide a mechanism to overcome imatinib resistance. Methods This phase Ib study of BGJ398 and imatinib was performed in patients with imatinib refractory advanced GIST. A standard 3 + 3 dosing schema was utilized to determine the recommended phase II dose (RP2D). Two treatment schedules were evaluated incorporating imatinib 400 mg daily in combination with (A) BGJ398 daily 3 weeks on, 1 week off or (B) BGJ398 daily 1 week on, 3 weeks off. Results 16 patients enrolled. The median age was 54 years (range: 44-77), 81% were male, and the median number of lines of prior therapy was 4 [range: 2-6, 13 patients had ≥3 prior therapies]. 12 patients received treatment on schedule A [BGJ398 dose range: 25 - 75 mg]: 2 patients experienced dose limiting toxicities (DLT) (n = 1, myocardial infarction & grade (G)4 CPK elevation; n = 1, G3 ALT elevation) on schedule A (BGJ398 75 mg), significant hyperphosphatemia, an on-target effect, was not observed, implying the maximum tolerated dose was below the therapeutic dose. Following protocol amendment, 4 patients enrolled on schedule B [BGJ398 dose range: 75 - 100 mg]: no DLTs were observed. The most common treatment related adverse events occurring in >15% of patients included CPK elevation (50%), lipase elevation (44%), hyperphosphatemia (24%), anemia (19%), and peripheral edema (19%). Among the 12 evaluable patients, stable disease (SD) was the best response observed in 7 patients by RECIST v1.1 and 9 patients by CHOI. Stable disease ≥ 32 weeks was observed in 3 patients (25%). Median progression free survival was 12.1 weeks (95% CI 4.7-19.5 weeks). Conclusions Toxicity was encountered with the combination therapy of BGJ398 and imatinib. Due to withdrawal of sponsor support the study closed before the RP2D or dosing schedule of the combination therapy was identified. In heavily pre-treated patients, stable disease ≥ 32 weeks was observed in 3 of 12 evaluable patients. Trial Registration: NCT02257541 .

Thyroid hormone inactivation in gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are resistant to traditional chemotherapy but are responsive to the tyrosine kinase inhibitors imatinib and sunitinib. The use of these agents has improved the outcome for patients but is associated with adverse effects, including hypothyroidism. Multiple mechanisms of this effect have been proposed, including decreased iodine organification and glandular capillary regression. Here we report the finding of consumptive hypothyroidism caused by marked overexpression of the thyroid hormone-inactivating enzyme type 3 iodothyronine deiodinase (D3) within the tumor. Affected patients warrant increased monitoring and may require supernormal thyroid hormone supplementation.

Promoter Hypermethylation and Its Impact on Expression of MGMT Gene in the GIT Malignant Patients of Kashmiri Origin.

Epigenetic alterations, in addition to multiple gene abnormalities, are involved in the genesis and progression of human cancers. Gastrointestinal tract (GIT) cancer is a major medical and economic burden worldwide. Aberrant methylation of CpG islands within promoter regions is associated with transcriptional inactivation of various tumor suppressor genes. Although a number of cancer-associated genes have been found to be hypermethylated in GIT cancer, valuable methylation markers for early diagnosis and prognostic evaluation of this cancer remain largely unknown. O6-methyguanine DNA methyltransferase (MGMT) is a DNA-repair gene that removes mutagenic and cytotoxic adducts from the O6 position of guanine induced by alkylating agents. MGMT promoter hypermethylation and reduced expression have been found in some primary human carcinomas. We studied DNA methylation of CpG islands of the MGMT gene and its relation with MGMT protein expression in human GIT carcinomas. A total of 210 GIT tumor samples and 90 adjacent normal tissues were analyzed for MGMT promoter methylation by methylation-specific polymerase chain reaction after bisulfite modification of DNA and same samples were analyzed for MGMT protein expression by Western blotting. The methylation frequencies of MGMT gene promoter were 41.4%, 34.2%, and 44.2% in stomach, esophageal, and colorectal cancer cases while as 16.6, 13.3, and 13.3 in respective controls. MGMT protein was found downregulated in controls of all GIT. The results suggest that methylation at CpG islands of MGMT may be responsible for the downregulation of MGMT protein expression in GIT cancers.

Prediction of severe toxicity in adult patients under treatment with 5-fluorouracil: a prospective cohort study.

5-Fluorouracil (5-FU) has long been used for the treatment of gastrointestinal tumors harboring interindividual variability in both the pharmacokinetic and the pharmacogenetic profiles, which in turn may lead to life-threatening toxicities. We carried out a prospective cohort study of adult patients initiating treatment with 5-FU between 2013 and 2015. Primary exposures of interest were the methylenetetrahydrofolate reductase single nucleotide polymorphism in exons 4 and 7 and 5'-untranslated region-thymidylate synthase VNTR genotypes, in addition to baseline clinical and demographic variables. The primary outcome was the time to the occurrence of severe toxicity. We used a Cox regression model to evaluate patients' survival and toxicity experience and its association with baseline characteristics and a priori determined genetic polymorphisms. A total of 197 patients were included, 40.1% developed severe toxicity during follow-up. Variables that were significantly associated with developing severe toxicity were the European Organization for Research and Treatment of Cancer functional score [hazard ratio (HR): 0.98; 95% confidence interval (CI): 0.97-0.99]; type of tumor [anus (HR: 2.50; 95% CI: 1.07-5.82), head and neck/esophagus/stomach (HR: 2.95; 95% CI: 1.64-5.33)] and 5-FU continuous infusion regimens over 4-5 days (HR: 9.35; 95% CI: 2.68-32.59). We found a significant association between baseline functional status, type of tumor and continuous infusion regimens and the occurrence of severe toxicity during the follow-up of patients receiving 5-FU. No association was found with the genotypic variants evaluated. Future validation and modeling of an everyday easy-to-use score to predict toxicity among these subgroup of patients remains warranted.

Cytochrome P450 1A1 gene polymorphisms and digestive tract cancer susceptibility: a meta-analysis.

Cytochrome P450 1A1 (CYP1A1) is a phase I enzyme that regulates the metabolism of environmental carcinogens and alter the susceptibility to various cancers. Many studies have investigated the association between the CYP1A1 MspI and Ile462Val polymorphisms and digestive tract cancer (DTC) risk in different groups of populations, but their results were inconsistent. The PubMed and Embase Database were searched for case-control studies published up to 30th September, 2015. Data were extracted and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the relationship. Totally, 39 case-control studies (9094 cases and 12,487 controls) were included. The G allele in Ile/Val polymorphism was significantly associated with elevated DTC risk with per-allele OR of 1.24 (95% CI = 1.09-1.41, P = 0.001). Similar results were also detected under the other genetic models. Evidence was only found to support an association between MspI polymorphism and DTC in the subgroups of caucasian and mixed individuals, but not in the whole population (the dominant model: OR = 1.19, 95% CI = 0.94-1.91, P = 0.146). In conclusion, our results suggest that the CYP1A1 polymorphisms are potential risk factors for DTC. And large sample size and well-designed studies with detailed clinical information are needed to more precisely evaluate our founding.

Aurora kinase A in gastrointestinal cancers: time to target.

Gastrointestinal (GI) cancers are a major cause of cancer-related deaths. During the last two decades, several studies have shown amplification and overexpression of Aurora kinase A (AURKA) in several GI malignancies. These studies demonstrated that AURKA not only plays a role in regulating cell cycle and mitosis, but also regulates a number of key oncogenic signaling pathways. Although AURKA inhibitors have moved to phase III clinical trials in lymphomas, there has been slower progress in GI cancers and solid tumors. Ongoing clinical trials testing AURKA inhibitors as a single agent or in combination with conventional chemotherapies are expected to provide important clinical information for targeting AURKA in GI cancers. It is, therefore, imperative to consider investigations of molecular determinants of response and resistance to this class of inhibitors. This will improve evaluation of the efficacy of these drugs and establish biomarker based strategies for enrollment into clinical trials, which hold the future direction for personalized cancer therapy. In this review, we will discuss the available data on AURKA in GI cancers. We will also summarize the major AURKA inhibitors that have been developed and tested in pre-clinical and clinical settings.

[Succinate dehydrogenase deficient gastrointestinal stromal tumor: a clinicopathologic analysis of eight cases].

OBJECTIVE: To study the clinicopathologic features, diagnosis and differential diagnosis of succinate dehydrogenase (SDH) deficient gastrointestinal stromal tumors (GISTs) as a unique tumor subtype. METHODS: SDHB and SDHA immunohistochemistry was performed in 120 gastric GISTs, in addition to CD117, DOG-1, CD34, smooth muscle actin (SMA), desmin, S-100 protein, cytokeratin (CK) and Ki-67. Subset of the cases was further evaluated for the presence of mutations in CKIT exons 9, 11, 13 and 17 mutations and platelet derived growth factor receptor alpha(PDGFRA) exons 12 and 18. RESULTS: Eight of 120 (6.6%) GIST cases were found SDH-deficient including 3 male and 5 female patients (median age of 36.2 years; ranging 16 to 65 years of age). The tumors involved antrum (6 cases), lesser curvature (1 case) and fundus (1 case). Macroscopically, the dominant tumor masses varied from 3 to 10 cm in diameter with a multinodular or plexiform pattern involving the gastric wall. Microscopically,tumor cells had predominantly epithelioid morphology, with occasional mixed spindle cell nodules. Lymphovascular invasion was identified in 5 cases. Immunohistochemistry for SDHB was negative in all 8 cases, and SDHA was negative in 5 cases. All 8 SDHB negative cases also expressed CD117, DOG-1 and CD34, but were negative for SMA, desmin, S-100 and CK. All 8 cases were found to have wild-type CKIT and PDGFRA genes. Available clinical follow-up were obtained in 7 cases, ranging from 2 to 60 months (median follow-up 23.3 months), and all patient were alive. Three cases were found to have liver metastases at their first diagnosis, and one developed omental and mesenteric metastases in 17 months. CONCLUSIONS: SDH-deficient GIST is a distinct subtype of GIST, with a predilection to occur in young and female patients. Characteristic pathological findings include multinodular gastric wall involvement, epithelioid cell morphology, frequently lymphovascular invasion with occasional lymph node and liver metastases, but an overall indolent clinical behavior. Immunohistochemistry for SDHB is required for the diagnosis.

Gastrointestinal Stromal Tumors - Diagnosis and Surgical Treatment.

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract, previously classified as leiomyomas, leiomyosarcomas, leiomyoblastomas or schwannomas. They are now recognized as a distinct entity with origin in the mesodermal interstitial cell of Cajal, cells that express the c-KIT protein (tirozine kinase receptor). The definitive diagnosis is established by immunohistochemistry, more than 95% of GISTs being positive for CD117. Despite the major progress of chemotherapy, the treatment of choice is surgery, and it implies the complete resection of the tumor. The evolution of these tumors is unpredictable and the prognosis depends on localization, tumor size and mitotic index. Benign tumors have an excellent prognosis after surgery, with a 5 year survival of 90%, while malignant tumors resistant to radiotherapy and chemotherapy have a dismal prognosis even after surgical resection, with a median survival of 1 year. We studied a group of 15 patients diagnosed with TSGI in the Surgery Clinic of the œProf. Dr. Agrippa Ionescu Clinical Emergency Hospital, between 2003 and 2013, following the particularities of presentation, diagnosis and treatment, with focus on the prognostic factors according to available literature data.

Tracing PAKs from GI inflammation to cancer.

P-21 activated kinases (PAKs) are effectors of Rac1/Cdc42 which coordinate signals from the cell membrane to the nucleus. Activation of PAKs drive important signalling pathways including mitogen activated protein kinase, phospoinositide 3-kinase (PI3K/AKT), NF-κB and Wnt/ß-catenin. Intestinal PAK1 expression increases with inflammation and malignant transformation, although the biological relevance of PAKs in the development and progression of GI disease is only incompletely understood. This review highlights the importance of altered PAK activation within GI inflammation, emphasises its effect on oncogenic signalling and discusses PAKs as therapeutic targets of chemoprevention.

Does CD10 expression individuate a GIST subgroup of patients?

AIM: The aim of the study was to evaluate expression of CD10 in a series of gastrointestinal tumors (GIST) and to find its relationship with prognosis, biological and clinical behavior. GISTs represent the most frequent gastrointestinal (GI) mesenchymal tumors. Biological behavior of GIST cannot be easily predicted; for this reason many biomolecular factors are being investigated to predict prognosis. Recently the role of the CD10 as prognostic predictor in the carcinogenesis of the gastrointestinal carcinomas has been accurately studied. To our knowledge, no data regarding the role of CD10 in GISTs have been published to date. METHODS: CD10 expression was searched by immunohistochemistry in 29 histological specimens of proved GIST surgically treated. Patients' characteristics and all pathologic features of tumors were statistically reviewed and compared to CD10 expression. Survival analysis was also calculated respect to CD10 expression and relevant clinical or pathological features. RESULTS: CD10 was expressed in 24.1% of cases. There was no correlation between CD10 positivity and risk category, morphology, size or mitosis. The CD10 expression status did not prove to be statistically related to worse prognosis, advanced disease (metastasis) or recurrence, however it was significantly correlated to the tumor site. CONCLUSION: CD10 expression in our series seems to be associated to a small bowel origin of tumor. CD10 expression alone failed to reveal a statistically significant prognostic value. However survival analysis revealed worse prognosis in stomach tumours with mitotic count >10/50 HPF.

Effects of aqueous soybean, mistletoe and red clover extracts on activities of adenosine deaminase and xanthine oxidase enzyme.

Soybean (Glycine max), mistletoe (Viscum album) and red clover (Trifolium pratence) have been argued to have anti-cancer effects. In the present study it was aimed to investigate possible effects of these plant extracts on the activities of DNA turn-over enzymes, namely adenosine deaminase (ADA) and xanthine oxidase (XO) in cancerous and non-cancerous gastric and colon tissues. For this aim, 6 cancerous and 6 non-cancerous adjacent human gastric tissues, and 7 cancerous and 7 non-cancerous adjacent colon tissues were obtained by surgical operations. Our results suggest that aqueous soybean, mistletoe and red clover extracts may exhibit anti-tumoral activity by depleting hypoxanthine concentration in the cancer cells through XO activation, which may lead to lowered salvage pathway activity necessary for the cancer cells to proliferate in the cancerous colon tissue. Some foods like soybean, mistletoe and red clover may provide nutritional support to medical cancer therapy through inhibiting and/or activating key enzymes in cancer metabolism (Tab. 4, Ref. 33).