Intestinal Gastrointestinal Stromal Tumors Research Articles

Outcomes of gastric and small Intestinal GISTs (Gastrointestinal Stromal Tumors) after curative resection and aggressive re-resection of recurrence; in Imatinib era: A propensity matched analysis.

Background: Surgical resection remains the mainstay of treatment for localized GISTs. Prognostication and need for adjuvant imatinib are based on risk stratification which includes tumor site as an important factor with small intestine lesions having poor prognosis as compared to gastric primary. Aim of this study is to evaluate oncological outcomes of gastric and small intestinal GIST patients undergoing curative resection, focusing on the role of primary tumor site as a prognostic indicator.

HAND1 and BARX1 Act as Transcriptional and Anatomic Determinants of Malignancy in Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumor (GIST) arises from interstitial cells of Cajal (ICC) or their precursors, which are present throughout the gastrointestinal tract. Although gastric GIST is commonly indolent and small intestine GIST more aggressive, a molecular understanding of disease behavior would inform therapy decisions in GIST. Although a core transcription factor (TF) network is conserved across GIST, accessory TFs HAND1 and BARX1 are expressed in a disease state-specific pattern. Here, we characterize two divergent transcriptional programs maintained by HAND1 and BARX1, and evaluate their association with clinical outcomes. We evaluated RNA sequencing and TF chromatin immunoprecipitation with sequencing in GIST samples and cultured cells for transcriptional programs associated with HAND1 and BARX1. Multiplexed tissue-based cyclic immunofluorescence and IHC evaluated tissue- and cell-level expression of TFs and their association with clinical factors. We show that HAND1 is expressed in aggressive GIST, modulating KIT and core TF expression and supporting proliferative cellular programs. In contrast, BARX1 is expressed in indolent and micro-GISTs. HAND1 and BARX1 expression were superior predictors of relapse-free survival, as compared with standard risk stratification, and they predict progression-free survival on imatinib. Reflecting the developmental origins of accessory TF programs, HAND1 was expressed solely in small intestine ICCs, whereas BARX1 expression was restricted to gastric ICCs. Our results define anatomic and transcriptional determinants of GIST and molecular origins of clinical phenotypes. Assessment of HAND1 and BARX1 expression in GIST may provide prognostic information and improve clinical decisions on the administration of adjuvant therapy.

A Case of Small Intestinal Gastrointestinal Stromal Tumor That Required Emergency Surgery After Preoperative Diagnosis of Intra-abdominal Abscess

A Case of Small Intestinal Gastrointestinal Stromal Tumor That Required Emergency Surgery After Preoperative Diagnosis of Intra-abdominal Abscess

A Thirteen and a Half Year Survival Case of Small Intestine Gastrointestinal Stromal Tumor with Multiple Liver Metastases Treated with Combined Therapies Including Radiofrequency Ablation

A Thirteen and a Half Year Survival Case of Small Intestine Gastrointestinal Stromal Tumor with Multiple Liver Metastases Treated with Combined Therapies Including Radiofrequency Ablation

A Case of Small Intestinal Gastrointestinal Stromal Tumor That was Difficult to Distinguish from an Ovarian Tumor: A Case Report

術前に卵巣腫瘍と鑑別が困難であった小腸Gastrointestinal stromal tumor（GIST）の手術症例を経験したので報告する．症例は67歳の女性．健診にて貧血を指摘され，近医で上下部消化管内視鏡検査を施行するも，異常所見なく，婦人科疾患の精査目的に当院産婦人科を紹介受診となった．骨盤部造影CT検査にて右卵巣に一致して内部造影不良域を伴う長径51mmの境界明瞭な腫瘤を認め，骨盤部造影MRI検査では子宮右側に53×38×48mm大の内部非造影領域と辺縁造影効果を伴う腫瘤を認めた．右卵巣腫瘍の診断で開腹子宮全摘，両側付属器切除術の予定となったが，開腹所見にて腫瘍は子宮や両側付属器と連続しておらず，小腸原発腫瘍と判明したため，術中に当科紹介となった．腫瘍の肉眼所見は壁外発育性のGIST様で小腸リンパ節の明らかな腫大を認めなかったため，小腸部分切除術を施行した．手術時間は１時間54分，出血は少量であった．術後経過は良好で術後第７病日に軽快退院となった．骨盤内に落ち込んだ小腸原発性腫瘍と卵巣腫瘍などの婦人科系腫瘍性疾患は鑑別が難しく，今回術前卵巣腫瘍と鑑別困難であった小腸GISTの手術症例を経験したため，文献的考察を交えて報告する．

Prognostic Impact of let-7e MicroRNA and Its Target Genes in Localized High-Risk Intestinal GIST: A Spanish Group for Research on Sarcoma (GEIS) Study.

Simple SummaryFor intestinal localized high-risk gastrointestinal stromal tumors (GIST) patients’ new molecular biomarkers are urgently needed for a more accurate prognosis. In our study, miRNA profiling analyses was planned to explore new molecular biomarkers with potential prognostic role in this clinical context. Our data, revealed that 39 microRNAs (miRNAs) were significantly deregulated when comparing patients with disease relapsed versus non-relapsed cases. The underexpression of a specific miRNA let-7e and the overexpression of 4 of its target genes (ACVR1B, CASP3, COL3A1 and COL5A2) correlated significantly with worse relapse-free survival. Overall, our results suggest that miRNA profiling is a potential molecular tool useful for a more accurate prognosis for intestinal localized high-risk GIST patients.MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level, and they have been described as being associated with tumor prognosis. Here, miRNA profiling was planned to explore new molecular prognostic biomarkers in localized intestinal high-risk GIST. Paraffin tumor blocks of 14 and 86 patients were used in the discovery and expansion sets, respectively. GeneChip miRNA v3.0 was employed to identify the miRNAs differentially expressed between relapsed and non-relapsed patient samples, which were validated in the expansion set, by qRT-PCR. RT2 Profiler PCR Array was used for the screening of let-7e targets. Expression levels were correlated with relapse-free survival and overall survival. In the discovery set, 39 miRNAs were significantly deregulated, let-7e and miR-550 being the most underexpressed and overexpressed miRNAs in the relapsed group, respectively. In the expansion set, the underexpression of let-7e or the overexpression of 4 of its target genes (ACVR1B, CASP3, COL3A1, and COL5A2) were statistically associated with worse relapse-free survival. The expression of let-7e and 4 of its target genes are potential prognostic biomarkers in high-risk localized intestinal GIST. The expression of these genes is a potential molecular tool useful for a more accurate prognosis in this subset of GIST patients.

Small intestine gastrointestinal stromal tumor and malignant peripheral nerve sheath tumor in a patient with neurofibromatosis type 1: A case report

AbstractThe clinical manifestation of neurofibromatosis type 1 (NF1) predisposes patients to the development of a variety of neoplasms, such as neurofibroma, malignant peripheral nerve sheath tumors (MPNSTs), optic pathway glioma, gastrointestinal stromal tumors (GISTs), and pheochromocytoma. We report the case of a patient with NF1 who underwent surgery for MPNST of the right upper abdominal wall in which a GIST arising in the jejunum was found incidentally. Two years later, the patient underwent surgical resection of a GIST in the small intestine owing to clinical manifestation of gastrointestinal hemorrhage. Further imaging examination is required for symptomatic plexiform neurofibroma to distinguish between an MPNST and other benign subcutaneous tumors. Patients with NF1 should undergo periodic computed tomography image surveillance because they are of increased risk of developing GISTs. Standard therapy for NF1‐GIST is surgery, and patients should be carefully followed up after tumor resection.

Abstract 5181: Therapeutic targeting of GPR20, selectively expressed in gastrointestinal stromal tumor (GIST), with DS-6157a, an antibody-drug conjugate (ADC)

Abstract More than 85% of GISTs are driven by activating mutations in KIT proto-oncogene receptor tyrosine kinase (KIT) or platelet-derived growth factor receptor alpha (PDGFRA). Currently, the only approved treatments for GIST are KIT directed tyrosine kinase inhibitors (TKIs). However, treatment with approved TKIs eventually results in disease progression most often due to the development of secondary resistance mutations in KIT. In addition, these agents have limited activity in PDGFRA mutant GIST and KIT/PDGFRA wild type (WT) GIST as primary therapy. Therefore, it is essential to develop novel therapeutic strategies with different modes of action in advanced GIST. G protein-coupled receptor 20 (GPR20) is an orphan GPCR selectively and abundantly expressed in GIST. GPR20 expression is regulated by FOXF1 and ETV1, transcription factors that play critical roles in KIT-driven GIST initiation, proliferation, and survival. We hypothesize that GPR20 is a potential therapeutic target for ADC development for the treatment of GIST. In this study, 1) GPR20 and KIT protein expression was assessed by IHC staining on GIST samples from DFCI (n=144) and NCCHE (n=100) as well as on normal and malignant tissue microarrays obtained commercially, and 2) an anti-GPR20 ADC (DS-6157a) was generated to evaluate antitumor activity in GIST models and to assess safety. GPR20 was expressed in more than 88% of the GIST samples analyzed, with higher expression levels in samples that: (I) received multiple treatment lines compared to naïve/early treated samples, (II) expressed higher KIT levels, (III) were small intestinal GIST, and/or (IV) had no KIT mutation, including succinate dehydrogenase (SDH) deficient GIST and neurofibromatosis type 1 (NF1)-associated GIST. The interstitial cells of Cajal were the only normal cells positive for GPR20. Normal mast cells expressed KIT but not GPR20. DS-6157a is an ADC composed of a humanized anti-GPR20 antibody, a Gly-Gly-Phe-Gly tetra-peptide-based linker, and a DNA topoisomerase I (TOP1) inhibitor Dxd. DS-6157a exhibited GPR20 expression-dependent cell growth-inhibitory activity and induced tumor regression with dosing at 3 to 10 mg/kg in multiple GIST xenograft models. In addition, DS-6157a showed antitumor activity in a GIST patient-derived xenograft model that was resistant to imatinib, sunitinib, and regorafenib. In vitro, DS-6157a induced TOP1 inhibitor-associated markers of DNA damage (phosphorylation of Chk1) and apoptosis (cleaved PARP) in GPR20 expressing cells. In preclinical toxicology studies using rats and cynomolgus monkeys, the pharmacokinetics and safety profile of DS-6157a were favorable at up to 200 mg/kg and 30 mg/kg, respectively. These data support the clinical development of DS-6157a as a potential novel GIST therapy with activity in patients that are resistant, refractory, or intolerant to approved TKIs. Citation Format: Kenji Iida, Amr H. Abdelhamid, Akiko Kawano Nagatsuma, Tomoko Shibutani, Satoru Yasuda, Michiko Kitamura, Chiharu Hattori, Manabu Abe, Jun Hasegawa, Takuma Iguchi, Tsuyoshi Karibe, Takashi Nakada, Koichiro Inaki, Reiko Kamei, Yuki Abe, Jessica L. Andersen, Sandro Santagata, Matthew L. Hemming, Suzanne George, Toshihiko Doi, Atsushi Ochiai, George D. Demetri, Toshinori Agatsuma. Therapeutic targeting of GPR20, selectively expressed in gastrointestinal stromal tumor (GIST), with DS-6157a, an antibody-drug conjugate (ADC) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5181.

A case of spontaneous mesenteric hematoma with diagnostic difficulty

BackgroundSpontaneous mesenteric hematoma (SMH) is a rare condition characterized by intraperitoneal hemorrhage of unknown etiology. SMH without worsening of general status allows conservative management; however, patients showing chronological changes on imaging require surgical intervention to rule out possible malignancy.Case presentationA 69-year-old man was referred to our hospital to evaluate an abdominal mass with no associated clinical symptoms. He had a history of chronic hepatitis C and diabetes mellitus. Six months earlier, computed tomography (CT) revealed a 75-mm tumor arising from the jejunum, suspected to be a gastrointestinal stromal tumor (GIST) of the small intestine. Following a further 6 months of observation, the patient was referred to our hospital. Abdominal contrast-enhanced CT revealed a well-defined heterogeneous round tumor with a maximum diameter of 75 mm adjacent to the upper jejunum. The tumor was accompanied by calcification at the periphery, with no evidence of augmentation over the prior 6 months. Diffuse lymphadenopathy was observed around the aorta and splenic artery. Under the diagnosis of GIST arising from small intestine, the patient underwent elective surgery. The resection revealed an elastic soft tumor at the mesentery adjacent to the upper jejunum with severe adhesion between the tumor and jejunum. The tumor origin was unclear; thus, we performed mesenteric excision and partial enterectomy without lymph node dissection.The tumor was surrounded by fibrous capsular tissue containing massive hemosiderin deposits and cholesterol crystals showing partial calcification, resulting in a diagnosis of spontaneous hematoma of the mesentery.ConclusionsWe report a case of SMH mimicking small intestinal GIST. It is difficult to diagnose long-established SMH because its radiological features change with time, and more case reports are needed to improve the accuracy of diagnosis.

Difference of computed tomographic characteristic findings between gastric and intestinal gastrointestinal stromal tumors.

We aimed to compare the computed tomography (CT) imaging differences between gastric and intestinal gastrointestinal stromal tumors (GISTs). Thirty-eight patients with 38 gastric GISTs and 27 with 31 intestinal GISTs were enrolled. Tumors were classified as small (< 5cm) or large (≥ 5cm). Qualitative and quantitative CT imaging characteristics on non-contrast and contrast-enhanced CT were evaluated by two radiologists independently and statistically compared. Early venous return and higher CT number of the draining vein in the arterial phase were more frequent in small-sized intestinal GISTs than in small-sized gastric GISTs (p < 0.001). Small-sized intestinal GISTs demonstrated a wash-out pattern, whereas small-sized gastric GISTs showed a plateau pattern. Contrast enhancement was higher in small-sized intestinal GISTs than in small-sized gastric GISTs (p < 0.001). CT number was inversely proportional to the diameter of intestinal GISTs in both arterial and venous phases but not to that of gastric GISTs. Strong enhancement with wash-out pattern and early venous return are characteristic findings of small-sized intestinal GISTs. Radiologists should be aware that CT findings of GISTs have a wide spectrum and may differ according to size and site of origin.

A surprise visitor at cesarean section: Gastrointestinal stromal tumor of the uterus

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors that almost always arise from the GI tract and account for 0.1-3% of GI tumors. During pregnancy, GIST is highly unusual given the predilection of this tumor to appear in the fifth to seventh decade of life. The finding of GISTs outside the GI tract is also rare as the cell of origin of these tumors is believed to be the interstitial cell of Cajal, found only in the GI tract. Extra intestinal GISTs have been reported with a few cases arising from the uterus or metastatic to the ovary; however; an asymptomatic uterine GIST occurring at pregnancy as an incidental finding during cesarean section has not been reported so far. We present a 32-year-old lady who underwent an emergency caesarean section and was found to have a GIST of the uterus. The tumor was excised in toto and she started imatinib therapy postoperatively. At the end of three years of close follow-up, she has done well with no evidence of recurrence.

Clinicopathologic and immunohistochemical features of gastrointestinal stromal tumors: a single-center experience

IntroductionHere we present our 10-year experience regarding gastrointestinal stromal tumors (GISTs) in terms of clinicopathologic features and immunohistochemical staining patterns.Material and methodsIn this single-center retrospective study, during 2008–2018, data of 26 patients with histologically confirmed diagnoses of GISTs were collected. All patients included in the study underwent surgical resection. The Mann-Whitney U test was used for continuous variables.ResultsThe mean age of the patients was 60.7 ±10.4 (35–79) years. The most common GIST location was the stomach (88.5%). The mean tumor size was 5.8 cm (1–13 cm) and the most common histologic type of GIST was spindle cell (61.5%). CD 117(c-kit) was positive in 96% of GIST cases, while CD34 was positive in 84.6%, discovered on GIST-1(DOG1) in 46.2%, smooth muscle actin (SMA) in 26.9%, S100 in 19.2%, and desmin in 7.7%. In one CD117 negative patient, DOG1 was positive. Four patients had metastases (15.4%). The mean follow-up time was 56.5 ±36.2 month. The length of hospital stay was significantly longer in patients who had small intestinal GIST (p = 0.010). In immunohistochemical staining, SMA was significantly more common among spindle cell type (p = 0.032).ConclusionsGISTs are very rare tumors of the gastrointestinal tract, but the accurate diagnosis with immunohistochemical staining is vital for the treatment. So, large scale, prospective and randomized multicenter trials are needed to reduce the misdiagnosis rate of GISTs.

Pediatric Female with Adult Type Small Intestine Gastrointestinal Stromal Tumor [GIST]: A case report

Background: Gastrointestinal stromal tumor [GIST] is commonest mesenchymal tumor, mainly affects adults. But, 1.5% to 2% GISTs were reported in pediatrics and adolescents. The treatment of GIST is managed as in adult because of lack of information about pediatric GIST. Aim of the work: Here we presented a case report of pediatric GIST. Current literature was reviewed and a summary was formulated to form a base for future optimal treatment of childhood GIST. Case summary: A 14 years Saudi female presented with vague abdominal pain and easy fatigability for 8 months. The pain located in lower abdomen, mild, waning, no aggravation or reliving factor and not radiating. Clinically, there was peri umbilical round, firm and not tender mass extending to right side of the abdomen till right hypochondrium, with no movement with respiratory movements. Investigations demonstrate severe microcytic hypochromic anemia. A computed tomography [CT] abdomen and pelvis showed evidence of soft tissue mass, about 13*11*12cm, of heterogeneous pattern and enhancement with area of hypodensity and cystic degeneration. There was necrosis of mesentery with some calcification seen inside the lesion suggestive of query GIST or Lymphoma. En block resection of the mass done with safety margin, biopsy from lymph node and side-to-side anastomosis done using linear stapler. The histopathological examination revealed ill and well defined fasicles of tumor cells that have spindle, oval and round shape nuclei invading mesentery and small bowel. Mitotic figurer 5-10/50 HPF, reactive lymph node. Immunohistochemistry showed diffused strong positive CD117 and CD34, negative S-100

Minimally invasive surgery for gastrointestinal stromal tumors--pursuing the trivial, or striving for perfection

Complete surgical resection is the main treatment for gastrointestinal stromal tumor (GIST). However, GIST is crisp with rich blood supply, and prone to rupture with improper handling, leading to intra-abdominal hemorrhage and tumor cell dissemination. With the development of technology and equipment, minimally invasive surgery is getting mature. However, according to a phase III, multicenter, randomized controlled trial published in the New England Journal of Medicine in November 2018, open surgery was superior to minimally invasive surgery for early cervical cancer, which warned us that the application of minimally invasive surgery in GIST should be understood dialectically. The general principle of minimally invasive surgery of GIST is avoiding tumor rupture, despite the different location and decision-making according to tumor location. For gastric GIST, minimally invasive surgery should be performed with tumor locating at the greater curvature or anterior wall of the stomach, and with a diameter less than 5 cm. Small intestinal GIST is more malignant and not recommended to undergo minimally invasive surgery, but the technique can be used to expose and locate the tumor. Colorectal GIST is rare but highly malignant, therefore open surgery should be the first choice. In fact, minimally invasive surgery for rectal GIST has certain advantages such as better visualization compared to open surgery. GIST in non-appropriate location, such as the esophagogastric junction, pylorus, and duodenum, should be treated with caution because of its close relationship with organ function. The general principle of GIST treatment is to completely remove the tumor while retaining organ function. The application of minimally invasive surgery should not cause extra damage to organ function or increase the risk of tumor rupture. Endoscopic treatment of GIST still lacks high-quality evidence-based studies. The application of minimally invasive surgery should be conservative. The purpose of performing minimally invasive surgery is not the technique itself, but to minimize the injuries to tissue and organs. In conclusion, we should perform minimally invasive surgery for appropriate patients cautiously on the basis of complete resection and function preservation.

Advances in radiological studies of gastrointestinal stromal tumors

The commonly used radiological examinations for gastrointestinal stromal tumor (GIST) include ultrasound, CT, magnetic resonance imaging and PET, which play important roles in the individualized treatment of GIST through the assistance of the detection, location, diagnose and differential diagnosis, biological behavior and risk evaluation, operation planning, therapeutic effects prediction and follow-up. Standardized predisposal, multi-planar reconstruction and multi-phase enhancement are of great significance in the detection of small GIST lesions. Differences in drainage vessels and enhancement characteristics of tumors are helpful in differentiating small intestinal GIST from pancreatic cancer, neuroendocrine tumors and other abdominal non-GIST tumors. Radiology can provide multiple indicators to qualitatively or quantitatively reflect the risk of GIST. Recent study found that the risk classification of GIST has correlation with necrosis, but not cystic degeneration. The risk stratification of GIST by dual-energy CT showed that CT value and standardized iodine concentration in arterial-venous and delayed phases of high-risk tumors were significantly higher than those of non-high-risk tumors. The correlation between tumor enhancement pattern and risk stratificationwas still controversial. Recently, the rise of radiomics and deep learning techniques provide new direction for risk assessment of GIST. Some studies used various models and parameters to predict the risk classifications of GIST and achieved AUC values above 0.85, and some results were also superior to conventional indicators and radiologists' subjective judgment in the prediction of exon 11 mutations, mitotic counts and survivals. Recent developments in PET and diffusion-weighted MRI provide more precise functional quantitative indicators for the prediction and early evaluation of the response of GIST to targeted therapy. These studies are constantly expanding our field of exploration, and prompting us to stride toward the goal of individualized treatment of GIST.

Transrectal EUS-FNA and Angiography Are Useful for the Treatment of Giant Small Intestine Gastrointestinal Stromal Tumors

Transrectal EUS-FNA and Angiography Are Useful for the Treatment of Giant Small Intestine Gastrointestinal Stromal Tumors

Comparative clinical features and short-term outcomes of gastric and small intestinal gastrointestinal stromal tumours: a retrospective study

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the gastrointestinal tract. Recent research has shown that small intestinal GISTs exhibit more aggressive features than gastric GISTs. To compare the clinical features of gastric and small intestinal GISTs for the further prediction of different prognoses, we conducted a retrospective study. 43 patients in the small intestine group and 97 in the gastric group were collected between January 2016 and December 2017. Data on demographics, preoperative lab results, clinicopathological results and surgical management were compared between groups. Significant elements were subsequently included in logistic regression analysis for further identification. The Kaplan-Meier method and log-rank test were used to calculate the relapse-free survival (RFS) rate and cumulative survival rate. Univariable analysis demonstrated that underlying disease, gastrointestinal (GI) bleeding, lymphocyte count, haemoglobin (Hb), albumin (ALB), platelet-to-lymphocyte ratio (PLR), thrombin time (TT), National Institutes of Health (NIH) category, Dog1, surgical procedure types and postoperative hospitalization were different between the two groups. Among these factors, logistic regression analysis identified that patients in small intestinal group exhibited significantly higher GI bleeding rate (p = 0.022), NIH category (p = 0.031), longer postoperative hospitalization time (p = 0.001) with lower TT value (p = 0.030) than those in gastric group. The log-rank test indicated that the location of the GIST (p = 0.022), GIST with GI bleeding (p = 0.027) and NIH category (p = 0.031) were independent prognostic predictors for poor outcome regarding RFS. Regarding cumulative survival, only the location of the GIST (p = 0.027) was an independent prognostic predictor for poor outcome. Thus, we concluded that small intestine GISTs were associated with lower TT, recurrent GI bleeding, advanced NIH category and extended postoperative hospitalization. Nevertheless, future multicentre prospective study are expected to validate our results.

The prognostic value of gastrointestinal bleeding in gastrointestinal stromal tumor: A propensity score matching analysis.

Background and objectivesWhether gastrointestinal (GI) bleeding indicates gastrointestinal stromal tumor (GIST) rupture and impacts prognosis is unclear. We examined the prognostic value of GI bleeding in GIST.MethodsPrimary GIST patients with (GB group) or without (NGB group) initial symptoms of GI bleeding were retrospectively studied. Propensity score matching (PSM) was conducted to reduce confounders.ResultsEight hundred patients were enrolled. Male gender [odds ratio (OR) = 1.517, P = 0.011], tumors in the small intestine (OR = 2.539, P < 0.001), and tumor size 5‐10 cm (OR = 2.298, P = 0.004) increased the odds of GI bleeding; age >60 years decreased the odds (OR = 0.683, P = 0.031). After PSM, 444 patients were included (222 in each group). Relapse‐free survival (RFS) (P = 0.001) and overall survival (OS) (P = 0.002) were both superior in the GB group. In subgroup analysis, the GB group achieved a superior RFS (P = 0.005) and OS (P = 0.007) in patients with small intestine GIST, but not stomach or colorectal GIST.ConclusionsGIST patients with age <60, male gender, tumors located in the small intestine, and tumors 5‐10 cm in size had a higher risk of GI bleeding. GIST patients with GI bleeding had a superior RFS and OS. This difference was statistically significant only in small intestine GIST.

Endoscopic characteristics of small intestinal malignant tumors observed by balloon-assisted enteroscopy.

BACKGROUNDCapsule endoscopy and balloon-assisted enteroscopy (BAE) enable visualization of rare small bowel conditions such as small intestinal malignant tumors. However, details of the endoscopic characteristics of small intestinal malignant tumors are still unknown.AIMTo elucidate the endoscopic characteristics of small intestinal malignant tumors.METHODSFrom March 2005 to February 2017, 1328 BAE procedures were performed at Keio University Hospital. Of these procedures, malignant tumors were classified into three groups, Group 1: epithelial tumors including primary small intestinal cancer, metastatic small intestinal cancer, and direct small intestinal invasion by an adjacent organ cancer; Group 2: small intestinal malignant lymphoma; and Group 3, small intestinal gastrointestinal stromal tumors. We systematically collected clinical and endoscopic data from patients’ medical records to determine the endoscopic characteristics for each group.RESULTSThe number of patients in each group was 16 (Group 1), 22 (Group 2), and 6 (Group 3), and the percentage of solitary tumors was 100%, 45.5%, and 100%, respectively (P < 0.001). Patients’ clinical background parameters including age, symptoms, and laboratory data were not significantly different between the groups. Seventy-five percent of epithelial tumors (Group 1) were located in the upper small intestine (duodenum and ileum), and approximately 70% of gastrointestinal stromal tumors (Group 3) were located in the jejunum. Solitary protruding or mass-type tumors were not seen in malignant lymphoma (Group 2) (P < 0.001). Stenosis was seen more often in Group 1, (68.8%, 27.3%, and 0%; Group 1, 2, and 3, respectively; P = 0.004). Enlarged white villi inside and/or surrounding the tumor were seen in 12.5%, 54.5%, and 0% in Group 1, 2, and 3, respectively (P = 0.001).CONCLUSIONThe differential diagnosis of small intestinal malignant tumors could be tentatively made based on BAE findings.

Association between CT imaging features and KIT mutations in small intestinal gastrointestinal stromal tumors

Small intestinal gastrointestinal stromal tumors (GISTs) have different clinical outcomes when KIT mutations are in exons 11 or 9, which are also the most common sites of neoplastic KIT mutations. The purpose of this study is to evaluate the CT imaging features in those two groups. A total of 35 patients were enrolled, and both quantitative and qualitative CT imaging features were compared between patient groups with KIT exon 9 mutations (KIT–9) and exon 11 mutations (KIT–11). The KIT–9 group was statistically associated with a tumor size larger than 10 cm and a higher enhancement ratio when compared with those of the KIT–11 group (both P < 0.05). For the enhancement ratio, the receiver operating characteristic curve indicated a cut-off value of 1.60 to differentiate KIT–9 from KIT–11 tumors. Additionally, tumor necrosis was more commonly seen in the KIT-9 group. In multivariate analysis, tumor size (β = 0.206; P = 0.022) and KIT–9 (β = 0.389; P = 0.006) were independent factors associated with tumor necrosis. Taken together, KIT–9 mutant tumors tended to have CT imaging features indicative of more aggressive neoplasms. These findings may be helpful in identifying more aggressive small intestinal GISTs and optimizing treatment.