Progress in the Treatment of Small Intestine Cancer.

OPINION STATEMENT: Small intestine cancer is rare, accounting for approximately 3% of all gastrointestinal malignancies. The most common histological subtypes include adenocarcinoma, neuroendocrine tumours (NETs) and gastrointestinal stromal tumours (GISTs). In localised disease, surgery remains the mainstay of treatment and the best approach to improve survival. Current treatment for small intestine adenocarcinoma (SIA) is extrapolated from small studies and data from colorectal cancer (CRC). There is limited evidence to guide therapy in the adjuvant setting. However, there are small phase II studies in the advanced setting providing evidence for the role of chemotherapy and immunotherapy. There is also limited evidence assessing the efficacy of targeted therapies. Small intestine NETs are rare, with evidence for somatostatin analogue therapy, particularly in the low to intermediate-grade well-differentiated tumours. Poorly differentiated NETs are generally managed with chemotherapy but have worse outcomes compared with well-differentiated NETs. The management of small intestine GISTs is largely targeting KIT mutations with imatinib. Recent trials have provided evidence for effective therapies in imatinib-resistant tumours and the potential role of immunotherapy. The aim of this article was to review the evidence for the current management and recent advances in the management of small intestine adenocarcinoma, NETs and GISTs.

Gastrointestinal Stromal Tumors: What Is the Best Sequence of TKIs?

OPINION STATEMENT: In our practice, we evaluate the mutation status of advanced unresectable disease to guide decisions on use of tyrosine kinase inhibitor (TKI) therapy. This review focuses on management of GIST with KIT and PDGFRA mutations. Imatinib is first-line treatment for unresectable gastrointestinal stromal tumors (GISTs) unless they harbor a PDGFRA D842V mutation; it is recommended to escalate imatinib to twice daily dosing for KIT exon 9 mutant tumors. When patients progress on first-line treatment, treatment is changed to sunitinib followed by regorafenib; while the spectrum of activity against resistance mutations varies with these agents, routine biopsies provide data on one area of disease and ctDNA has not been validated prospectively. For those with a PDGFRA D842V mutation, avapritinib is the first TKI to lead to tumor response and disease control. Ripretinib is approved in the 4th line setting, with limited data on its benefit for PDGFRA D842V GIST. Avapritinib can be considered for treatment beyond ripretinib for KIT mutant disease. The efficacy of other TKIs tested in GIST is reviewed. Ongoing therapy provides palliative benefit and should be continued given rapid decline observed off of treatment.

Liquid Biopsy in Gastrointestinal Stromal Tumors: Ready for Prime Time?

OPINION STATEMENT: Gastrointestinal stromal tumor (GIST) constitutes a paradigm for clinically effective targeted inhibition of oncogenic driver mutations. Therefore, GIST has emerged as a compelling clinical and biological model to study oncogene addiction and to validate preclinical concepts for drug response and drug resistance. Oncogenic activation of KIT or PDGFRA receptor tyrosine kinases is the essential drivers of GIST progression throughout all stages of the disease. Interestingly, KIT/PDGFRA genotype predicts the response to first-line imatinib and to all tyrosine kinase inhibitors (TKIs) approved or in investigation after imatinib failure. Considering that TKIs are effective only against a subset of KIT or PDGFRA resistance mutations, close monitoring of tumor dynamics with non-invasive methods such as liquid biopsy emerges as a necessary step forward in the field. Liquid biopsy, in contrast to solid tumor biopsy, aims to characterize tumors irrespective of heterogeneity. Although there are several components in the peripheral blood, most recent studies have been focused on circulating tumor (ct)DNA, due to the technological feasibility, the stability of DNA itself and DNA alterations, and the therapeutic development in precision oncology largely based on the identification of genetic driver mutations. In the present review, we systematically dissect the current wealth of data of ctDNA in GIST. To do so, a critical understanding of the promises and limitations of the current technologies will be followed by an exposition of the knowledge gathered with such studies in GIST. Collectively, our goal is to establish clear premises that can be used as the foundations to build future studies towards the clinical implementation of ctDNA evaluation in GIST patients.

Revolutions in treatment options in gastrointestinal stromal tumours (GISTs): the latest updates

OPINION STATEMENT: The treatment of advanced GIST is rapidly evolving with the development of novel molecular compounds such as avapritinib and ripretinib, but also promising results have been achieved with cabozantinib in a phase II trial. The availability of over five lines of treatment for patients with advanced GIST is likely to completely shift the current second-line and third-line treatment options, and will also potentially enable a personalised approach to treatment. Imatinib will most likely remain as the first-line treatment of choice for the vast majority of GIST patients. However, for GIST patients with tumours harbouring a D842V mutation in PDGFRA exon 18, avapritinib has shown efficacy and will become first-line therapy for this molecular subgroup. For second- and third-line treatment, results are awaited of a number of clinical trials. However, second-line and further treatment could potentially be tailored depending on secondary mutations found in imatinib-resistant GISTs. As secondary resistance to TKIs remains the biggest challenge in the treatment of GIST and despite negative results with alternating regimens in phase II, combination treatments should be further evaluated to tackle this issue. Moreover, the favourable safety profiles observed with avapritinib and ripretinib suggest that combination treatments are feasible, for instance, combining two TKIs or a TKI with drugs targeting downstream signalling pathways, such as PI3K inhibitors or MEK inhibitors. Finally, in line with further personalisation of treatment in GIST, a multidisciplinary approach is essential, and local treatment options, such as RFA, resection in case of unifocal progression, and radiotherapy, should be considered.

Defining Tumor Rupture in Gastrointestinal Stromal Tumor.

Tumor rupture is an important risk factor predictive of recurrence after macroscopically complete resection of gastrointestinal stromal tumors (GISTs), and an indication for defined interval or even lifelong adjuvant therapy with imatinib according to guidelines. However, there is no consensus or universally accepted definition of the term 'tumor rupture', and, consequently, its incidence varies greatly across reported series. Without predefined criteria, the clinical significance of rupture has also been difficult to assess on multivariate analysis of retrospective data. We reviewed the relevant literature and international guidelines, and, based on the Oslo criteria, proposed the following six definitions for 'tumor rupture': (1) tumor fracture or spillage; (2) blood-stained ascites; (3) gastrointestinal perforation at the tumor site; (4) microscopic infiltration of an adjacent organ; (5) intralesional dissection or piecemeal resection; or (6) incisional biopsy. Not all minor defects of tumor integrity should not be classified as rupture, i.e. mucosal defects or spillage contained within the gastrointestinal lumen, microscopic tumor penetration of the peritoneum or iatrogenic damage only to the peritoneal lining, uncomplicated transperitoneal needle biopsy, and R1 resection. This broad definition identifies GIST patients at particularly high risk of recurrence in population-based cohorts; however, its applicability in other sarcomas has not been investigated. As the proposed definition of tumor rupture in GIST has limited evidence based on the small number of patients with rupture in each retrospective study, we recommend validating the proposed definition of tumor rupture in GIST in prospective studies and considering it in clinical practice.

The rare coexistence of high titer inhibitor development and gastrointestinal stromal tumor in a patient with severe hemophilia: A case report.

Hemophilia is a hereditary disease with impaired blood coagulation due to a genetic deficiency of blood coagulation factors. The development of inhibitors further complicates the course of the disease and management. The case is here reported of a haemophilia patient who presented with coexisting development of high titer inhibitor with Gastrointestinal Stromal Tumor (GIST) diagnosis and was admitted with upper gastrointestinal system bleeding. The patient had no prior history of inhibitor presence. During all procedures including surgery, excellent hemostasis was achieved with rFVIIa treatment and no hemorrhagic complication was observed. To the best of our knowledge, this constitutes the first reported case of GIST associated with inhibitor development in a hemophilia A patient.

Latest advances in adult gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are the most common GI tract mesenchymal tumors. GIST patients are optimally managed by a precision medicine approach. Herein, we discuss the latest advances in precision medicine and ongoing clinical trials relevant to GIST. Circulating tumor DNA for detection of mutational changes could replace tissue biopsies and radiographic imaging once validated. Most GISTs are KIT/PDGFRα mutated, and despite the good clinical response to imatinib, treatment is generally not curative, more often due to secondary mutations. New mechanisms to bypass this resistance by inhibiting KIT downstream pathways and by targeting multiple KIT or PDGFRα mutations are being investigated. Immunotherapy for GIST patients is in its infancy. These approaches may lead to more effective, less toxic therapies.

Efficacy and Clinical Outcomes of Transcatheter Arterial Embolization for Gastrointestinal Bleeding from Gastrointestinal Stromal Tumor.

PURPOSE: To evaluate the efficacy and clinical outcomes of transcatheter arterial embolization (TAE) for gastrointestinal (GI) bleeding from gastrointestinal stromal tumor (GIST). MATERIALS AND METHODS: TAE was performed in 20 referred patients (male:female = 13:7; median age, 56.3 y) for GI bleeding from GISTs. The locations of GISTs were assessed using contrast-enhanced computed tomography (CT) and catheter angiography. The technical and clinical success of TAE and clinical outcomes including procedure-related complications, recurrent bleeding, 30-day and overall mortality, and cumulative survival were evaluated. RESULTS: The sites of GIST-related bleeding or tumor staining were the jejunum (n = 9), stomach (n = 5), ileum (n = 3), duodenum (n = 2), and jejunum and colon (n = 1). Angiography showed bleeding from GIST in 5 patients, and tumor staining was noted in only 15 patients. TAE was performed for patients with and without contrast medium extravasation on angiography. Technical and clinical success rates of TAE were 95% (19 of 20 patients) and 90% (18 of 20 patients), respectively. Recurrent bleeding was noted in 1 patient. There were no procedure-related complications. In 15 patients, surgical resection of the tumors was performed after TAE. The 30-day and overall mortality rates were 10% (2 of 20 patients) and 30% (6 of 20 patients), respectively. CONCLUSIONS: TAE is a safe and effective method for controlling GI bleeding from the GIST.

Perforated gastrointestinal stromal tumor (GIST) in a true jejunal diverticulum in adulthood: report of a case.

A 61-year-old man was referred to us for investigation of acute abdominal pain. Computed tomography showed a 5.9 × 5.3 × 5.0 cm lump of food residue in the jejunum, and a large amount of free air and ascites around the liver and right paracolic gutter. He underwent emergency laparotomy for suspected peritonitis from perforation by a foreign body in the small intestine. We identified purulent exudate in the abdominal cavity and perforation of a jejunal cystic mass, attached ~40 cm from Treitz's ligament at the anti-mesenteric side of the jejunum. Based on a diagnosis of jejunal duplication with perforation, we resected that part of the small intestine and performed intra-abdominal drainage. Pathological findings confirmed the diagnosis of a perforated gastrointestinal stromal tumor (GIST) in a true jejunal diverticulum. Histopathological evidence suggests that intestinal pressure and/or hemorrhage can cause perforation in the background of a true jejunal diverticulum. To our knowledge, this is the first case report of a perforated GIST in a true jejunal diverticulum.

[GIST of the small bowel in neurofibromatosis terrain as a source of massive bleeding]. / GIST tenkého streva v terénu neurofibromatózy jako zdroj masivního krvácení

Neurofibromatosis type I (Morbus Von Recklinghausen) is an autosomal dominant disorder. The major diagnostic criteria include multiple cutaneous neurofibromas, café au lait spots, that are rarely found in the gastrointestinal tract. 5-25% of these lesions, however, may develop into gastrointestinal stromal tumours. We report the case of a 69-year-old woman with Von Recklinghausen disease. She was admitted due to gastrointestinal bleeding. During surgery we found, among multiple neurofibromatic intestinal lesions, macroscopically different bleeding tumours. They were completely removed. Histological examination revealed gastrointestinal stromal tumour. Using an immunohistological assay, we examined stored specimens from previous operations on the same patient: one anal polyp removed a year ago and tumours removed 32 years ago and regarded as polyps then were re-classified as gastrointestinal stromal tumours. In the discussion, the authors address the issue of which examination of the intestine would be appropriate to find out the source of bleeding in the small intestine and how to distinguish intestinal stromal tumours in the terrain of intestinal neurofibromatosis. Another issue addressed is a screening examination in patients with skin forms of Recklinghausens disease. To successfully manage intestinal bleeding, close cooperation among the surgeon, the endoscopist and the radiologist is indispensable. In order to quickly establish the right diagnosis and subsequently target treatment promptly, it is very helpful to know the patients exact personal medical history and also the possible complications of chronic diseases.

Promoting role of cholecystokinin 2 receptor (CCK2R) in gastrointestinal stromal tumour pathogenesis.

The cholecystokinin 2 receptor (CCK2R/CCKBR) is expressed in gastrointestinal stromal tumours (GISTs). We sought to investigate the role of CCK2R in GIST pathogenesis. Molecular characterization of CCK2R was performed on a heterogeneous cohort of 50 GISTs. In addition, CCK2R expression was evaluated by immunohistochemistry (IHC), using tissue microarray (TMA) containing 292 GISTs, two cases of hyperplasia of interstitial Cajal's cells (ICC) and six gastric microscopic GISTs. Mono-allelic loss of the CCK2R/11p15 allele was identified in 13.7% of GISTs, having no impact on the level of CCK2R transcript expression. No CCK2R mutations were found. The CCK2Ri4sv, CCK2R splice variant with retention of intron 4 was detected in six of 20 tumours analysed. Wild-type CCK2R transcripts were commonly expressed (57.1% of cases) and this expression was highly correlated with gastric primary site of GISTs (p < 0.001). At the protein level, expression of CCK2R in incidental ICC hyperplasia and early stages of gastric GIST development was documented, and its gastric association was confirmed on GIST-TMA by IHC. To explore the in vivo effect of CCK2R activation on tumour growth, gastrin versus placebo was administered intraperitoneally in nude mice carrying human GIST xenografts. The tumour volume was followed for 10 weeks. The effect of this stimulation on tumour cell proliferation/apoptosis was assessed by IHC and KIT/PKC-θ signalling was evaluated by western blotting (WB). In vivo experiments showed a two-fold increase in the volume of tumours which were exposed to gastrin in comparison with non-exposed controls (p = 0.03), with a significant increase in mitotic activity (p = 0.04) and Ki-67 proliferation index (p = 0.008). By WB, gastrin stimulation resulted in hyper-activation of KIT and PKC-θ kinases, and in evident PI3K-AKT pathway over-activation. Our results indicate a promoting role of CCK2R on GIST tumourigenesis, particularly in tumours of gastric origin.

Giant gastrointestinal stromal tumor (GIST) of the stomach cause of high bowel obstruction: surgical management.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) represent 85% of all mesenchymal neoplasms that affect the gastrointestinal (GI) tract. These GISTs range in size from small lesions to large masses. Often they are clinically silent until they reach a significant size, so their discovery is usually incidental. CASE PRESENTATION: A 67-year-old man was admitted at our general surgery department with a persistent abdominal pain in the left hypochondrium, associated with nausea and vomiting. Clinical examination revealed a palpable mass in the epigastrium and in the left hypochondrium, which was approximately 40 cm long. Ultrasonography and computed tomography of the abdomen showed a large mass of 40 × 25 cm, which extended from the posterior wall of the stomach to the spleen, involving the body and the tail of the pancreas. The patient underwent en-block resection of the mass, sleeve resection of the stomach, and distal pancreatectomy-splenectomy. The histopathology of the resected specimen was consistent with a gastrointestinal stromal tumor of the stomach (positive for CD 117) with a high risk of malignancy (mitotic count >5/50 high-power fieldand Ki67/Mib1 >10%). The postoperative course was uneventful and treatment with imatinib mesylate began immediately. The patient appears to be disease free after four years. CONCLUSIONS: Giant GISTs of the stomach are rare. Surgical resection with curative intent is feasible. The combination of surgical resection and imatinib can provide long-termdisease-free survival. An R0 resection is the best achievable treatment, therefore the patient should be evaluated over time for potential resectability.

Gastrointestinal stromal tumor arising in an ileal duplication: report of a case.

This report presents the extremely rare case of an adult patient who presented with peritonitis caused by the perforation of an ileal duplication, associated with a gastrointestinal stromal tumor (GIST) arising within the duplication. A 70-year-old female was admitted to the hospital with lower abdominal pain. Abdominal computed tomography showed free air in the peritoneal cavity. An emergency laparotomy was performed, presuming diffuse peritonitis caused by a perforation of the gastrointestinal tract. The surgical findings showed that the peritonitis was caused by the perforation of an ileal duplication, 90 cm proximal to the ileocecal valve, with an extrinsic tumor protruding from the duplication. A segmental resection of the ileum-including the tumor and ileal duplication-was performed. Histopathology showed that the tumor was composed of spindle-shaped and epithelioid cells. The tumor was immunohistochemically positive for KIT, with a deletion mutation spanning the intron 10-exon 11 boundary. Accordingly, a diagnosis was made of a GIST arising within a duplication of the ileum. Duplications of the alimentary tract are encountered only occasionally in adults. Although quite rare, malignant change should therefore be considered as a possible complication when a solid portion is observed within a duplication of the alimentary tract.

Pancreas-preserving segmental duodenectomy for gastrointestinal stromal tumor of the duodenum and splenectomy for splenic angiosarcoma.

BACKGROUND: Gastrointestinal stromal tumors are the most common mesenchymal tumors of the gastrointestinal tract and occur rarely in the duodenum. Splenic angiosarcoma is an aggressive neoplasm with an extremely poor prognosis. METHODS: We report a case of a 70-year-old man hospitalized for abdominal pain in the upper quadrants, dyspepsia and nausea, previously treated for Hodgkin lymphoma 30 years ago. Abdominal CT showed a solid nodular lesion in the third portion of the duodenum, the presence of retropancreatic, aortic and caval lymph nodes, and four nodular splenic masses. (111)In-octreotide scintigraphy revealed pathological tissue accumulation in the duodenal region, and in the retropancreatic, retroduodenal, aortic and caval lymph nodes, suggesting a nonfunctioning neuroendocrine peripancreatic tumor. RESULTS: At exploratory laparotomy, an exophytic soft tumor was found originating from the third portion of the duodenum. Pancreas-preserving duodenectomy with duodenojejunostomy, splenectomy and lymphnodectomy of retropancreatic aortic and caval lymph nodes were performed. Pathological evaluation and immunohistochemical studies showed the presence of a duodenal gastrointestinal stromal tumor with low mitotic activity and a well-differentiated angiosarcoma localized to the spleen and invading lymph nodes. CONCLUSIONS: We speculated that the angiosarcoma and duodenal gastrointestinal stromal tumors of this patient were due to the treatment of Hodgkin lymphoma with radiotherapy 30 years ago. Pancreas-preserving segmental duodenectomy can be used to treat non-malignant neoplasms of the duodenum and avoid extensive surgery. Splenectomy is the treatment of choice for localized angiosarcomas but a strict follow-up is mandatory because of the possibility of recurrence.

Transforming growth factor ß repressor, SnoN, is overexpressed in human gastrointestinal stromal tumors.

PURPOSE: The transforming growth factor bgr; (TGF-ß)/ Smad pathway is implicated in the development of interstitial cells of Cajal. The aim of this study was to examine the role of this pathway in human gastrointestinal stromal tumors (GISTs). METHODS: The expression of TGF-ß receptor II (TßRII), phosphorylated Smad2 (p-Smad2), SnoN, p21(WAF17sol;CIP1) and p27(KIP1) was examined by immunohistochemistry in 30 hu-man GISTs in relation to prognostic factors. RESULTS: TßRII was expressed in 76.9% of the cases. All cases were positive for p-Smad2 and SnoN, with significantly higher expression levels in small intestinal compared to gastric GISTs. Downregulation of p21(WAF1/CIP1) and p27(KIP1) was found in 78.6% and 46.4% of the cases respectively, while cytoplasmic expression of p27(KIP1) was also noted in 50% of GISTs. CONCLUSIONS: TGF-ß/Smad pathway may contribute to GIST pathogenesis. SnoN overexpression and low levels of p21(WAF1)/CIP1 and p27(KIP1) may be of importance in GISTs.

Rapid Flow Cytometry of Gastrointestinal Stromal Tumours Closely Matches the Modified Fletcher Classification.

AIM: We aimed to develop a rapid, simple procedure and an algorithm for quantitative analysis and classification of the metastatic risk of gastrointestinal stromal tumours (GIST) for clinical use. MATERIALS AND METHODS: Eighteen specimens from laparoscopic local gastrectomy were assessed by flow cytometry. We devised a new risk classification for GIST by combining flow cytometry parameters with tumour size and evaluated whether the combined parameters correlated with the modified Fletcher risk classification. RESULTS: We found a significant correlation between clinical prognostic factors (mitotic count and Ki-67 labelling index) and the flow cytometry parameters DNA ploidy, DNA index and S-phase fraction. The combined parameters established from tumour size and the flow cytometry parameters showed a high correlation with the modified Fletcher risk classification (p=0.0064). Flow cytometry had to be performed for approximately 10 minutes to determine the metastatic risk. CONCLUSION: Rapid flow cytometry parameters can classify risk without the need for histological analysis.

Low Distribution of TIM-3+ Cytotoxic Tumor-Infiltrating Lymphocytes Predicts Poor Outcomes in Gastrointestinal Stromal Tumors.

There are multiple tumor-infiltrating lymphocytes (TILs) and relevant immune checkpoints existing in gastrointestinal stromal tumor (GIST), which provides opportunities and rationales for developing effective immunotherapies. Recent studies have suggested that checkpoint TIM-3/Gal-9 plays a pivotal role on immune response in multiple tumors, similar to the PD-1/PD-L1, emerging as a potential therapeutic target. However, their functions in GIST are unrevealed. Hence, the expression of immune checkpoints TIM-3 and Gal-9, as well as the infiltration of CD8+ T cells and NK cells, is described in 299 cases of GIST specimens. The results showed that TIM-3 and Gal-9 are mainly expressed in TILs, rarely in tumor cells. Expression levels of TIM-3 and Gal-9 significantly differ in varying risks of GIST and exert opposite distribution trends. Indicated by prognosis analysis, high TIM-3 expression of TILs was associated with improved outcome, while low expression levels of TIM-3 in combination with low amounts of CD8+ and CD56+ TILs predict extremely poor survival. The integrated analysis of TIM-3+, CD8+, and CD56+ TILs as one biomarker is a reliable independent predictor of prognosis. In conclusion, low densities of TIM-3+ TILs are associated with poor survival, and integrated immune biomarkers lead to superior predictors of GIST prognosis.

Synchronous occurrence of myelodysplastic syndrome and a bleeding jejunal gastrointestinal stromal tumor in a patient with obscure gastrointestinal bleed.

The coexistence of gastrointestinal (GI) stromal tumors (GISTs) and other malignancies, both synchronous or metachronous, has been discussed extensively in literature. It has also been described that the frequency of malignancies among patients with GIST is significantly higher than that in the general population. We present a case report of a patient with synchronous occurrence of myelodysplastic syndrome (MDS) and a GIST who presented with chronic fatigue and an episode of syncope and was found to have obscure GI bleed. Laboratory investigations revealed severe anemia, marrow picture was suggestive of MDS, and magnetic resonance imaging of the abdomen revealed a proximal small bowel neoplasm. She underwent resection of the diseased segment and anastomosis. The histopathology of the specimen confirmed the diagnosis of a GIST arising from the jejunum. She was started on imatinib on postoperative day 21 and is presently well preserved and on regular follow-up. The possibility of small bowel neoplasm, especially GIST, must be considered in patients diagnosed with chronic anemia secondary to obscure GI bleed and the possibility of a synchronous GIST, although uncommon must be considered in patients with myeloproliferative disorders and leukemia.