Small Gastrointestinal Stromal Tumors Research Articles

Clinical outcomes of endoscopic resection for the treatment of intermediate- or high-risk gastric small gastrointestinal stromal tumors: a multicenter retrospective study.

Many studies of gastric gastrointestinal stromal tumors (g-GISTs) following endoscopic resection (ER) have typically focused on tumor size, with most tumors at low risk of aggressiveness after risk stratification. There have been few systematic studies on the oncologic outcomes of intermediate- or high-risk g-GISTs after ER. From January 2014 to January 2020, we retrospectively collected patients considered at intermediate- or high-risk of g-GISTs according to the modified NIH consensus classification system. The primary outcome was overall survival (OS). Six hundred and seventy nine (679) consecutive patients were diagnosed with g-GISTs and treated by ER between January 2014 and January 2020 in three hospitals in Shanghai, China. 43 patients (20 males and 23 females) were confirmed at intermediate-or high-risk. The mean size of tumors was 2.23±1.01 cm. The median follow-up period was 62.02±15.34 months, with a range of 28 to 105 months. There were no recurrences or metastases, even among patients having R1 resections. The 5-year OS rate was 97.4% (42/43). ER for intermediate- or high-risk gastric small GISTs is a feasible and safe method, which allows for a wait-and-see approach before determining the necessity for imatinib adjuvant or surgical treatment. This approach to g-GISTs does require that patients undergo close follow-up.

Comparable long‑term survival outcomes of endoscopic treatment versus surgical treatment for gastrointestinal stromal tumors with a diameter of 5–10 cm

Currently, endoscopic treatment for small gastrointestinal stromal tumors (GIST) has been widely accepted. However, for tumors larger than 5 cm, endoscopic treatment has not been recognized by national guidelines as the standard therapy due to concerns about safety and adverse tumor outcomes. Therefore, this study compares the long-term survival outcomes of endoscopic treatment and surgical treatment for GIST in the range of 5–10 cm. We selected patients with GIST from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Kaplan–Meier analysis and the log-rank test were employed to compare the long-term survival outcomes between endoscopic treatment and surgical treatment. A multivariate Cox proportional hazards model was used for analysis to identify risk factors influencing patient prognosis. To balance baseline data, we performed 1:1 propensity score matching (PSM). A total of 1223 GIST patients were included, with 144 patients (11.8%) received endoscopic treatment and 1079 patients (88.2%) received surgical treatment. Before PSM, there was no significant difference in the long-term survival rates between the two groups [5-year OS (86.5% vs. 83.5%, P = 0.42), 10-year OS (70.4% vs. 66.7%, P = 0.42)]. After adjusting for covariates, we found that the overall survival (HR = 1.26, 95% CI 0.89–1.77, P = 0.19) and cancer-specific survival (HR = 1.69, 95% CI 0.99–2.89, P = 0.053) risks were comparable between the endoscopic treatment group and the surgical treatment group. In the analysis after PSM, there was no significant difference between the endoscopic treatment group and the surgical treatment group. Our study found that for GIST patients with tumor sizes between 5 and 10 cm, the long-term OS and CSS outcomes were similar between the endoscopic treatment group and the surgical treatment group.

The Value of Computed Tomography in Differentiating Heterotopic Pancreas from Small Gastrointestinal Stromal Tumor.

It is critical for an accurate preoperative diagnosis of heterotopic pancreas (HP) and small gastrointestinal stromal tumor (GIST), given the unique treatment and prognosis of the two tumors. This study aims to investigate HP's computed tomography (CT) features and identify the distinguishing characteristics between HP and small GIST. From January 2016 to August 2020, our hospital database was searched for confirmed histopathological results and CT scans for HP and GIST for further analysis. The statistically significant variables were determined by using Fisher's exact test, the Mann-Whitney U test, the receiver operating characteristic (ROC) curve and the inverse probability weighting method. CT images and clinical data were reviewed for 24 participants with HP and 34 patients with small GIST. Contour, border, relative enhancement grade, surface dimple, duct-like structure, short diameter (SD), attenuation of each lesion in the unenhanced phase (Lp), and the enhancement ratio of tumor in the venous phase (ER) were significant for differentiating HP from small GIST. Threshold values for SD and Lp were 1.40 cm and 42.33 Hounsfield units, respectively. Ill-defined border, surface dimple, ductlike structure, and Lp were independent factors that differentiated HP from small GIST. Additionally, SD and ER were also found to be independent factors. Contour, relative enhancement grade, SD, and Lp could effectively differentiate HP from small GIST, demonstrating improved diagnostic performance compared to other parameters. The presence of ductlike structures and surface dimples could further characterize HP. These findings may help distinguish HP from small GIST and avoid unnecessary invasive examination and therapy in individuals with asymptomatic HP.

A Rare Case of Epithelioid Variant of Duodenal Gastrointestinal Tumour

Gastrointestinal stromal tumours (GISTs) are uncommon mesenchymal neoplasms of the digestive tract that develop from pluripotent mesenchymal stem cells. GISTs develop from interstitial cells of Cajal or their precursors that are distributed throughout the muscular wall of the gastrointestinal tract.
 Rare mesenchymal neoplasms of the gastrointestinal tract called gastrointestinal stromal tumours (GISTs) are derived from pluripotent mesenchymal stem cells. The interstitial cells of Cajal or their progenitors, which are dispersed throughout the muscular wall of the gastrointestinal system, give rise to gastrointestinal stromal tumours (GISTs). At a median age of 55–60 years old, they have an incidence of 10–20/million each year.[1-4] They develop mostly in the stomach (60%) and small intestine (35%) before developing in the rectum, oesophagus, omentum, and mesentery more than 5%. [2] Only less than 5% of GISTs are duodenal.[5] The majority of cases are sporadic, however 5% involve a family condition, such as neurofibromatosis type 1 or the Carney triad.[2] As a result of blockage, anaemia, or gastrointestinal bleeding from a core ulceration, they typically manifest with abdominal discomfort. The discovery of small duodenal GISTs during gastroscopy is possible.
 Within the GIST category, the epithelioid variant represents a distinct subtype that is less common than other variants, such as spindle cell or mixed cell types. The overall prevalence of epithelioid GISTs is relatively low compared to other subtypes. Large extragastric components may extend intraluminally or to the serosal side in larger tumours. GISTs have non-specific abdominal pain and distention as their clinical signs and symptoms; as a result, diagnosis and treatment are frequently delayed, which result in therapeutic failures and high morbidity and fatality rates. GISTs can exhibit a variety of histological subtypes under a microscope, including the spindle cell type (70%) and the epithelioid type (20–25%), as well as the combined spindle cell and epithelioid type. [6] The histopathological features of epithelioid GISTs have been extensively studied in the literature. One study by Pai et al. (2016) found that epithelioid GISTs had higher cellularity, higher mitotic counts, and more prominent nucleoli than other GIST subtypes. [7] Cytologically, the features of duodenal GIST resemble those of adenocarcinoma. Epithelioid Duodenal GIST must be differentiated from adenocarcinoma.
 We are reporting the case of a 68-year-old female who complained of pain abdomen, and constipation since 1 year. Pain was associated with nausea, vomiting, not able to digest food solid>liquid and USG guided FNAC was advised. Cytological features confirmed the diagnosis of epithelioid variant of duodenal GIST.

Gastrointestinal Stromal Tumor (GIST)


 
 
 Gastrointestinal stromal tumor (GIST) are the most common mesenchymal tumor of the gastrointestinal tract and most common malignancy of the small intestine. Although the exact prevalence of GIST is not known, GIST was recognized as tumor it's arise from interstitial cells of Cajal. Most of the GISTs driven by a KIT or platelet-derived growth factor receptor alpha (PDGFRA) mutation. Histologically, GISTs look like spindle cell tumors most of the time, but they can be epitheoid or mixed type. Clinically, patients with small GISTs remain asymptomatic. In another case, patients with larger GISTs present with various symptoms depending on the location of the GISTs. Most of GISTs are located in the stomach or small bowel. But, they can involve almost any segment of the gastrointestinal tract from distal esophagus to anus. Diagnosis is suspected on imaging and endoscopic studies, and confirmed by tissue acquisition with immunohistochemical staining. The various endoscopic modalities of resection are increasingly tried. Surgical resection is the treatment of choice. In management of larger GISTs, tyrosine kinase inhibitors are extremly useful. Treatment options for metastatic GISTs also include radiotherapy, chemotherapy, hepatic artery embolization, chemoembolization, and radiofrequency ablation.
 
 

#3154 MALIGNANT HYPERCALCEMIA IN A CASE OF SMALL BOWEL GASTROINTESTINAL STROMAL TUMOUR

Abstract Background and Aims Malignant hypercalcemia is the most common cause of hypercalcemia, occurring in 30% of cancer patients and rendering a poor prognosis. Most cases have a humoral cause, the majority mediated by parathyroid hormone related peptide (PTHrP), rarely by 1,25-dihydroxyvitamin D3 (1,25(OH)2D) and very rarely by parathyroid hormone (PTH) ectopic production; other cases are due to local osteolysis. In the literature, there are only 5 reported cases of hypercalcemia associated to gastrointestinal stromal tumour (GIST), only 2 of them due to 1,25(OH)2D overproduction. Method Case report. Results Sixty-two years-old male with small bowel GIST diagnosed in 2014, subjected to enterectomy and on tyrosine kinase inhibitor (TKI) since 2017. TKI was changed from imatinib to sunitinib 25mg since August 2020 to the present date due to disease progression with liver metastasis. In March 2022, a PET scan showed no bone or soft tissue metastasis and there was a finding of right ureteral lithiasis with asymptomatic mild pyelocaliceal dilation. The patient had also subclinical hypothyroidism and several episodes of acute kidney injury (AKI) associated with hypercalcemia and hyperphosphatemia managed in outpatient clinic. He did not take any other medication besides the TKI. In April 2022, symptoms of disequilibrium, confusion, asthenia, and anorexia drove the patient to the Oncology Department. At physical examination the patient had an ECOG 3, was disoriented, cachectic and dehydrated, with no other noticeable findings. Blood lab tests showed a serum creatinine (sCr) of 2,86 mg/dL (baseline 1,10 mg/dL, estimated glomerular filtration rate of 72 mL/min/1,73 m2), a corrected serum total calcium (sCa) of 16,6 mg/dL and a normal serum phosphate of 4,0 mg/dL. The patient was admitted in the oncology ward with the collaboration of the nephrology department and was started on fluid therapy with 3000–4000cc NaCl 0,9%/day for a target urinary output of 75–200 mL/h. Hypercalcemia work-up showed low PTH of 8,8 pg/dL (reference range: 12–65 pg/dL). Measurement of PTHrP and 1,25(OH)2D were requested but took longer. After 3 days, despite the improvement of both sCr (2,23 mg/dL) and sCa (13,6 mg/dL), zoledronic acid was started. Results revealed an increased 1,25(OH)2D of 309 pg/dL (reference range: 10,9-79,3 pg/dL) and negative PTHrP. At the 6th day, a clear improvement of analytical (sCr 1,60 mg/dL; sCa 11,9 mg/dL) and clinical status, so the patient was discharged. The diagnosis was GIST 1,25(OH)2D overproduction causing malignant hypercalcemia and prednisolone on 20mg id was started. In June 2022, the patient had tumour progression, presenting lethargic, disoriented, and dehydrated; blood lab results showed AKI (sCr 1,97 mg/dL) and worsening hypercalcemia (sCa 14,7 mg/dL). He was admitted for fluid therapy and bisphosphonates but, even though there was a recovery of the hypercalcemia and renal function, the patient's clinical status got worse and he had a fatal outcome in the following days. Conclusion Malignant hypercalcemia caused by GIST 1,25(OH)2D overproduction is a rare condition. The work-up of an oncological patient with ureteral lithiasis and recurrent hypercalcemia should prompt us to a more in-depth investigation.

Progress in the Treatment of Small Intestine Cancer.

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.

Differentiation of Small Gastrointestinal Stromal Tumor and Gastric Leiomyoma with Contrast-Enhanced CT.

The value of multiphase contrast-enhanced CT in differentiating gastrointestinal stromal tumors (GISTs) and gastric leiomyomas (GLMs) which were ≤3 cm was evaluated using machine learning. A retrospective analysis was conducted on 45 cases of small gastric wall submucosal tumors (including 22 GISTs and 23 GLMs) with pathologically confirmed diameter ≤3 cm and completed multiphase CT-enhanced scan images. The CT features including tumor location, maximum diameter, shape, margins, growth pattern, plain/enhanced CT value, cystic degeneration, calcification, ulcer, progressive reinforcement, perilesional lymph nodes, and the CT value ratio of the tumor to the aorta at the same level in the enhanced phase III scan of the two groups were evaluated. Tumor location and maximum diameter were automatically evaluated by machine learning. The GISTs and GLMs with a diameter ≤3 cm showed clear margins, uniform density on plain scan CT, and progressive homogeneous enhancement. The age of the GISTs is greater than that of the GLMs group. The plain scan CT value of the GISTs group was lower than that in the GLMs group. In the GISTs group, the lesions were mostly located in the fundus (68.18%), showing a mixed growth pattern (54.55%), and in the GLMs group, most lesions were located in the cardia (47.82%), showing an intraluminal growth pattern (95.65%). The abovementioned differences were statistically significant. Contrast-enhanced CT has limited value in differentiating small GISTs from GLMs, which are ≤3 cm. Older age (>49.0 years), a low plain CT value (<42.5 Hu), mixed growth inside and outside the cavity, and noncardiac location tended to be the criteria for the diagnosis of small GISTs of the gastric wall.

Small Gastric Stromal Tumors: An Underestimated Risk

Small gastrointestinal stromal tumors (GISTs) are defined as tumors less than 2 cm in diameter, which are often found incidentally during gastroscopy. There is controversy regarding the management of small GISTs, and a certain percentage of small GISTs become malignant during follow-up. Previous studies which used Sanger targeted sequencing have shown that the mutation rate of small GISTs is significantly lower than that of large tumors. The aim of this study was to investigate the overall mutational profile of small GISTs, including those of wild-type tumors, using whole-exome sequencing (WES) and Sanger sequencing. Thirty-six paired small GIST specimens, which were resected by endoscopy, were analyzed by WES. Somatic mutations identified by WES were confirmed by Sanger sequencing. Sanger sequencing was performed in an additional 38 small gastric stromal tumor samples for examining hotspot mutations in KIT, PDGFRA, and BRAF. Somatic C-KIT/PDGFRA mutations accounted for 81% of the mutations, including three novel mutation sites in C-KIT at exon 11, across the entire small gastric stromal tumor cohort (n = 74). In addition, 15% of small GISTs harbored previously undescribed BRAF-V600E hotspot mutations. No significant correlation was observed among the genotype, pathological features, and clinical classification. Our data revealed a high overall mutation rate (~96%) in small GISTs, indicating that genetic alterations are common events in early GIST generation. We also identified a high frequency of oncogenic BRAF-V600E mutations (15%) in small GISTs, which has not been previously reported.

Pure endoscopic resection versus laparoscopic assisted procedure for upper gastrointestinal stromal tumors: Perspective from a surgical endoscopist.

Management of upper gastrointestinal (UGI) tract gastrointestinal stromal tumor (GIST) has evolved significantly over the past two decades. For GIST size smaller than 5 cm, laparoscopic resection has become the current standard. To avoid postoperative gastric deformity and preserve gastric function, laparoscopic endoscopic cooperative surgery (LECS) was developed and various modifications have been reported and utilized successfully. Pure endoscopic resection techniques have also been reported at a similar period of time, which further push the boundary of incisionless surgery in managing these lesions. Both tunneling and nontunneling exposed type endoscopic full thickness resection are well described procedures for resection of small UGI GIST. In this review, a summary of these procedures is provided, and the pros and cons of each technique from the perspective of a surgical endoscopist are discussed in detail. LECS and endoscopic resection are complementary to each other. The choice of technique should be tailored to the location, morphology, and size of the target lesions, taking into account the experience of the laparoscopic surgeons and endoscopists.

Efficacy of endoscopic ultrasound in the evaluation of small gastrointestinal stromal tumors.

BACKGROUNDGastrointestinal stromal tumors (GISTs) with a diameter of < 2 cm are called small GISTs. Currently, endoscopic ultrasound (EUS) is widely used as a regular follow-up method for GISTs, which can also provide a preliminary basis for judging the malignancy potential of lesions. However, there are no studies on the accuracy of EUS to assess the malignant potential of small GISTs.AIMTo evaluate the efficacy of EUS in the diagnosis and risk assessment of small GISTs.METHODSWe collected data from patients with small GISTs who were admitted to Shengjing Hospital of China Medical University between October 2014 and July 2019. The accurate diagnosis and risk classifications of patients were based on the pathological assessment according to the modified National Institute of Health criteria after endoscopic resection or laparoscopic surgery. Preoperative EUS features (marginal irregularity, cystic changes, homogeneity, ulceration, and strong echogenic foci) were retrospectively analyzed. The assessment results based on EUS features were compared with the pathological features.RESULTSA total of 256 patients (69 men and 187 women) were enrolled. Pathological results included 232, 16, 7, and 1 very low-, low-, intermediate-, and high-risk cases, respectively. The most frequent tumor location was the gastric fundus (78.1%), and mitoses were calculated as > 5/50 high power field in 8 (3.1%) patients. Marginal irregularity, ulceration, strong echo foci, and heterogeneity were detected in 1 (0.4%), 2 (0.8%), 22 (8.6%), and 67 (65.1%) patients, respectively. However, cystic changes were not detected. Tumor size was positively correlated with the mitotic index (P < 0.001). Receiver operating curve analysis identified 1.48 cm as the best cut-off value to predict malignant potential (95% confidence interval: 0.824–0.956). EUS heterogeneity with tumor diameters > 1.48 cm was associated with higher risk classification (P < 0.05).CONCLUSIONSmall GISTs (diameters > 1.48 cm) with positive EUS features should receive intensive surveillance or undergo endoscopic surgery. EUS and dissection are efficient diagnostic and therapeutic approaches for small GISTs.

S1846 The GIST of Abdominal Pain With Jaundice

Introduction: Gastrointestinal Stromal Tumors (GISTs) are subepithelial neoplasms characterized by the expression of KIT protein (CD117 antigen). They are the most common non-epithelial neoplasms of the GI tract, often found in the stomach and distal small intestine, with small GISTs often undiagnosed. GISTs have malignant potential, but nodal involvement is rare, explaining why surgical resection is usually first line treatment. Adjuvant treatment following resection or neoadjuvant treatment in the setting of unresectable/metastatic GISTs may produce an improved median survival. We present a patient with painful jaundice found to have GIST. Case Description/Methods: A 70-year-old man with a history of lung cancer, coronary artery disease, and nephrolithiasis presented with waxing and waning diffuse abdominal pain occasionally radiating to the back for three weeks. Associated symptoms included increased eructation, decreased appetite, generalized weakness, steatorrhea, rust-colored urine, and jaundice. The pain worsened with fatty meals and improved with defecation. The patient appeared jaundiced with conjunctival icterus. Abdomen was soft, non-distended with right upper quadrant tenderness, voluntary guarding and hypoactive bowel sounds. Labs revealed a cholestatic pattern of liver enzymes indicating obstruction. Of note, the CA 19-9 level was 142. Biliary imaging was performed (Figure A), which showed peripancreatic mass and severe biliary stricture in the lower third of main bile duct (Figure B). Pathology results of fine needle biopsy indicated low-grade spindle cell neoplasm consistent with GIST, CD117, CD34 and smooth muscle actin positive, S-100 and desmin negative. Given the location of the tumor, elective robotic pancreaticoduodenectomy was performed two months later with nodal resection. Discussion: Historically, the presentation of painful jaundice is associated with extrahepatic cholestasis including intrinsic and extrinsic tumors (cholangiocarcinoma, pancreatic cancer), choledocholithiasis, primary sclerosing cholangitis, acute pancreatitis, sphincter of Oddi dysfunction or biliary tract strictures following invasive procedures. The unusual location of this patient’s GIST led to differential diagnoses that did not include his ultimate diagnosis. This case report highlights the presentation of an often undiagnosed cancer, GIST, especially given its unique location in the GI tract. It is vital that as clinicians we keep a broad differential while performing workups of abdominal pain with jaundice.Figure 1.: Biliary Imaging. A: RUQ abdominal ultrasound demonstrating hydropic gallbladder 11.5 cm in length with sludge. B: ERCP fluoroscopy showing evidence of biliary duct stricture.

Therapeutic Effects of 4 Surgical Approaches for Small Gastrointestinal Stromal Tumors: A Network Meta-analysis.

This study aims to systematically evaluate the efficacy of endoscopic resection (ER), laparoscopic resection (LR), laparoscopic endoscopic cooperative surgery (LECS), and open surgery (OpS) for gastrointestinal stromal tumors with small diameters (≤5cm). Relevant studies were collected through Pubmed, Cochrane Library, and Embase databases. Operative time, hospital stays, time to liquid diet, intraoperative bleeding, and complications were used as outcome indicators for meta-analysis. Twenty-four retrospective cohort studies with 2406 participants were analyzed. LR and OpS groups had longer operating time than the ER group. ER, LECS, and LR groups had decreased lengths of hospital stay than the OpS group. Moreover, patients in LR and LECS groups had fewer complications than those in the OpS group. Endoscopic operation for small gastrointestinal stromal tumors contributes to shortened lengths of surgery and hospital stay. This reduces intraoperative blood loss and promotes gastroenteric functional recovery without increasing the risk of complications or tumor recurrence.

Efficacy and Safety of Endoscopic Resection for Small Gastric Gastrointestinal Stromal Tumors in Elderly Patients.

Background Gastrointestinal stromal tumors (GISTs) are prevalent in elderly patients. Endoscopic resection has become popular for treating small (≤5 cm) gastric GISTs. However, little is known about the outcomes of endoscopic resection in elderly patients. Aim To assess the efficacy and safety of endoscopic resection for small (≤5 cm) gastric GISTs in elderly patients (≥65 years old). Methods A total of 260 patients (265 lesions) with gastric GISTs treated via endoscopic resection from January 2011 to May 2020 were retrospectively analyzed. Among them, 65 patients were ≥65 years old (elderly group), and 195 patients were <65 years old (nonelderly group). Clinicopathological characteristics, postoperative complications, and tumor recurrence rates between the two age groups were compared. Results A total of 260 patients with primary small (≤5 cm) gastric GISTs were treated with endoscopic resection. The median ages of the elderly and nonelderly groups were 68 (range 65-83) years and 55 (range 32-64) years, respectively. Elderly patients showed a higher incidence of comorbidities compared with nonelderly patients (61.5% versus 32.3%s, respectively; p < 0.001). All elderly patients and 99.0% of nonelderly patients underwent en bloc resection; only two nonelderly patients received piecemeal resection. No significant differences were found regarding postoperative complications or tumor recurrence rates between the two groups. Conclusions Although elderly patients had more comorbidities than nonelderly patients, both groups had similar postoperative complications and recurrence rates. We suggest that endoscopic resection performed by experienced endoscopists is safe and effective for treating small (≤5 cm) gastric GISTs in elderly patients.

The Diagnosis of Small Gastrointestinal Subepithelial Lesions by Endoscopic Ultrasound-Guided Fine Needle Aspiration and Biopsy.

Endoscopic ultrasonography (EUS) has been widely accepted in the diagnosis of all types of tumors, especially pancreatic tumors, lymph nodes, and subepithelial lesions (SELs). One reason is that the examination can provide a detailed observation, with tissue samples being immediately obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Many SELs are detected incidentally during endoscopic examinations without symptoms. Most SELs are mesenchymal tumors originating from the fourth layer, such as gastrointestinal stromal tumors (GISTs), leiomyomas, and schwannomas. GISTs are potentially malignant. Surgical treatment is recommended for localized GISTs of ≥20 mm. However, the indications for the diagnosis and follow-up of GISTs of <20 mm in size are controversial. There are several reports on the rapid progression or metastasis of small GISTs. Therefore, it is important to determine whether a SEL is a GIST or not. The main diagnostic method is EUS-FNA. Recently, endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) using a new biopsy needle has been reported to obtain larger tissue samples. Additionally, various biopsy methods have been reported to have a high diagnostic rate for small GISTs. In local gastric SELs, regardless of the tumor size, EUS can be performed first; then, EUS-FNA/B or various biopsy methods can be used to obtain tissue samples for decision-making in relation to therapy and the follow-up period.

Clinical outcomes of endoscopic treatment for gastric gastrointestinal stromal tumors: a single-center study of 240 cases in China

Background and aims Endoscopic resection (ER) gradually becomes an important treatment method for gastrointestinal stromal tumors (GISTs). The aim of this study is to evaluate the efficacy and safety of ER of gastric GISTs. Methods This retrospective study included 240 patients with gastric GISTs who underwent ER at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2010 to December 2019. The clinicopathologic, endoscopic and follow-up data of the patients were collected and analyzed. Results The mean maximum tumor diameter was 1.67 ± 1.00 cm (range 0.2–6.5 cm), of which 156 cases (65.00%) were small gastric GISTs (tumor diameter < 2 cm). A total of 43 patients (17.92%) had perioperative bleeding, including 40 cases (16.67%) of minor bleeding and three cases (1.25%) of major bleeding. Perioperative perforation occurred in 101 patients (42.08%), of which 51 patients (21.25%) were active perforation and 50 patients (20.83%) were passive perforation. The en bloc resection rate was 97.08% (233/240), and seven cases (2.92%) had piecemeal resection. There were three cases (1.92%) of small gastric GISTs at intermediate risk and one case (0.64%) at high risk. A total of 193 patients were followed up, and no tumor residual, recurrence or metastasis occurred within a median follow-up time of 30 months (range 1–127 months). Conclusions Endoscopic treatment for gastric GISTs is safe and effective. Piecemeal resection does not seem to be related to the patient's prognosis. Endoscopic resection can be performed if patients are willing to remove small gastric GISTs.

Long-term prognosis of small gastric gastrointestinal stromal tumors with high histological grade: a longitudinal nested cohort study.

Gastrointestinal stromal tumors (GIST) are mostly seen in the stomach. Clinical data on GISTs ≤ 2cm with > 5 mitosis/50 HPFs are limited. This study aimed to analyze small GISTs with high histological grades to gain a more comprehensive understanding of their clinical characteristics with long-term follow-up. This was a nested cohort study of patients with gastric GISTs ≤ 2cm and > 5 mitosis/50 HPFs. Individuals with endoscopically resected gastric specimens diagnosed as GISTs between January 2008 and July 2019 were enrolled. We analyzed baseline clinicopathological characteristics, perioperative characteristics, risk of recurrence, and metastasis during follow-up. A total of 55 patients diagnosed with gastric GISTs ≤ 2cm and > 5 mitosis/50 HPFs were enrolled. The mean tumor size was 1.6±0.4cm (median 1.7cm, range 0.8-2.0cm). ESD was performed in 33 patients (60.0%) and EFTR in 22 patients (40.0%). Mean mitotic figures were 8.9/50 HPFs. Postoperative bleeding in one patient (1.8%) was the only severe adverse event. The mean follow-up period was 61.2±33.9months (median 53months, range 13-133months). Five patients (5/55, 9.1%) received additional therapies, including partial gastrectomy and adjuvant Imatinib. Only two patients (2/55, 3.6%) showed signs of recurrence. We observed no significant difference regarding baseline clinical characteristics and recurrence among GISTs with mitosis < 10/50 HPF and ≥ 10/50 HPF. No patient had signs of metastasis during follow-up. Endoscopic resection of gastric GISTs ≤ 2cm with > 5 mitosis/50 HPFs has a low risk of recurrence and metastasis in the long term. Endoscopic resection of GISTs is safe and feasible.

Fibrinogen-like protein 2 in gastrointestinal stromal tumour.

Gastrointestinal stromal tumour (GIST), the most common sarcoma of the gastrointestinal tract, can be treated effectively with tyrosine kinase inhibitors, such as imatinib. Cancer immune therapy has limited efficacy, and little is known about the immune suppressive factors in GISTs. Fibrinogen‐like protein 2 (FGL2) is expressed either as a membrane‐associated protein or as a secreted soluble protein that has immune suppressive functions. We found that GISTs expressed FGL2 mRNA highly compared to other types of cancer in a large human cancer transcriptome database. GIST expressed FGL2 frequently also when studied using immunohistochemistry in two large clinical series, where 333 (78%) out of the 425 GISTs were FGL2 positive. The interstitial cells of Cajal, from which GISTs may originate, expressed FGL2. FGL2 expression was associated with small GIST size, low mitotic counts and low tumour‐infiltrating lymphocyte (TIL) counts. Patients whose GIST expressed FGL2 had better recurrence‐free survival than patients whose GIST lacked expression. Imatinib upregulated FGL2 in GIST cell lines, and the patients with FGL2‐negative GIST appeared to benefit most from long duration of adjuvant imatinib. We conclude that GISTs express FGL2 frequently and that FGL2 expression is associated with low TIL counts and favourable survival outcomes.

A case of a small gastrointestinal stromal tumor of the stomach detected by upper gastrointestinal X-ray examination during a Ningen dock

A case of a small gastrointestinal stromal tumor of the stomach detected by upper gastrointestinal X-ray examination during a Ningen dock

Small-sized gastrointestinal stromal tumors: Is there an association between expectant management and overall survival?

BackgroundSmall-sized gastrointestinal stromal tumors (GISTs) have limited malignant potential. Few studies evaluate the safety and efficacy of expectant management (EM) for patients presenting with small GIST. MethodsWe queried the National Cancer Database to identify patients ≤65 years presenting with GISTs smaller than 3 cm in size between 2004 and 2015. Patients undergoing EM were 1:3 propensity score matched for relevant covariates to patients undergoing resection. Kaplan-Meier (KM) analysis of matched cohorts was used to evaluate the association between EM and overall survival (OS). Results1330 patients met inclusion criteria; 966 (72.6%) had gastric GISTs. 1196 (89.9%) underwent resection; 134 (10.1%) EM. 117 patients undergoing EM were propensity-matched to 356 patients undergoing resection. There was no difference in 5-year OS between patients undergoing EM and those undergoing resection (95.7% vs 92.6%, p = 0.4882). ConclusionsSurvival for small GISTs is similar with expectant management or resection.