Current research and treatment for gastrointestinal stromal tumors

Influence of lymph node removal on the prognosis of high malignancy potential gastric gastrointestinal stromal tumors: Insights from population-based study

High malignancy potential gastric gastrointestinal stromal tumors (HMP-gGISTs) generally require surgical resection. However, the necessity of lymph node removal (LR) for patients with such tumors remains unclear. Therefore, we conducted a population-based study to analyze the impact of LR on the long-term prognosis of patients with HMP-gGISTs. Patients with HMP-gGISTs were gathered from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was utilized to address potential selection bias. Overall survival (OS) and cancer-specific survival (CSS) were evaluated using Kaplan-Meier analyses and multivariate Cox proportional hazards models. A total of 840 patients with HMP-gGISTs were included in the study, with 317 undergoing LR and 523 not undergoing LR. The prognosis for OS (P = 0.026) and CSS (P < 0.001) in the LR group was worse compared to the No-LR group. After PSM, 634 patients were matched for comparison. The results showed that the OS (P = 0.028) and CSS (P = 0.006) in the LR group remained poorer than those in the No-LR group. Subgroup analysis further indicated that patients who did not undergo LR had a better prognosis. Our findings suggest that LR may not improve the prognosis of patients with HMP-gGISTs, implying that LR may not be necessary for these patients.

Insulin-like growth factor 2 targets IGF1R signaling transduction to facilitate metastasis and imatinib resistance in gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are typical gastrointestinal tract neoplasms. Imatinib is the first-line therapy for GIST patients. Drug resistance limits the long-term effectiveness of imatinib. The regulatory effect of insulin-like growth factor 2 (IGF2) has been confirmed in various cancers and is related to resistance to chemotherapy and a worse prognosis.

AIM

To further investigate the mechanism of IGF2 specific to GISTs.

METHODS

IGF2 was screened and analyzed using Gene Expression Omnibus (GEO: GSE225819) data. After IGF2 knockdown or overexpression by transfection, the phenotypes (proliferation, migration, invasion, apoptosis) of GIST cells were characterized by cell counting kit 8, Transwell, and flow cytometry assays. We used western blotting to evaluate pathway-associated and epithelial-mesenchymal transition (EMT)-associated proteins. We injected transfected cells into nude mice to establish a tumor xenograft model and observed the occurrence and metastasis of GIST.

RESULTS

Data from the GEO indicated that IGF2 expression is high in GISTs, associated with liver metastasis, and closely related to drug resistance. GIST cells with high expression of IGF2 had increased proliferation and migration, invasiveness and EMT. Knockdown of IGF2 significantly inhibited those activities. In addition, OE-IGF2 promoted GIST metastasis in vivo in nude mice. IGF2 activated IGF1R signaling in GIST cells, and IGF2/IGF1R-mediated glycolysis was required for GIST with liver metastasis. GIST cells with IGF2 knockdown were sensitive to imatinib treatment when IGF2 overexpression significantly raised imatinib resistance. Moreover, 2-deoxy-D-glucose (a glycolysis inhibitor) treatment reversed IGF2 overexpression-mediated imatinib resistance in GISTs.

CONCLUSION

IGF2 targeting of IGF1R signaling inhibited metastasis and decreased imatinib resistance by driving glycolysis in GISTs.

Robot-assisted laparoscopic combined with endoscopic partial gastrectomy (RALE-PG) for the treatment of gastric gastrointestinal stromal tumors in challenging anatomical locations: single-center experience

Background

Gastric gastrointestinal stromal tumors in challenging anatomical locations are difficult to remove.

Methods

This study retrospectively analyzed the clinical data of 12 patients with gastric GISTs in challenging anatomical locations who underwent robot-assisted laparoscopic combined with endoscopic partial gastrectomy (RALE-PG) and manual suturing of the gastric wall.

Results

This study included 12 patients with a mean age of 56.8 ± 9.8 years and a mean BMI of 23.9 ± 1.9 kg/m2. Tumors were located in the GEJ (n = 3), lesser curvature (n = 3), posterior gastric wall (n = 3) and antrum (n = 3). The cardia and pylorus were successfully preserved in all patients regardless of the tumor location. The mean tumor size was 4.5 ± 1.4 cm. The mitotic-count/50 mm2 was less than 5 in all patients (100%). There was no intraoperative tumor rupture (0%) and no conversion to open surgery (0%). The median operation time was 122 (97-240) min, and the median blood loss volume was 10 (5-30) ml. The median postoperative VAS score was 2 (2-4). The median time to first flatus was 2 (2-3) days. The median time to first fluid intake was 2 (2-3) days. The median time to first ambulation after the operation was 3 (2-4) days. No cases of anastomotic stenosis or leakage were found. The median time to drain removal for 6 patients was 5 (4-7) days. The median time to nasogastric tube removal for all patients was 2 (1-5) days. The median postoperative hospital stay was 5 (4-8) days. One patient (female/41 year) developed moderate anemia (Clavien-Dindo grade II complication). There was no unplanned readmission within 30 days after the operation. The median distance from the tumor to the resection margin was 1 (1-2) cm. R0 resection was achieved in all patients. The median follow-up period was 19 (10-25) months, and all patients survived with no recurrence or metastasis.

Conclusions

RALE-PG is a safe, feasible and advantageous technique for treating GISTs in challenging anatomical locations. It can be used to accurately remove the tumor while preserving gastric function to the greatest extent, but long-term oncologic outcomes need to be evaluated in a study with a larger sample size and longer follow-up period.

Surgical Management of Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are considered rare, but they are one of the most common malignant mesenchymal tumors within the gastrointestinal tract, affecting 4,000 to 6,000 adults in the United States each year. Because gastrointestinal bleeding is often the initial symptom, a thorough and timely diagnostic workup is imperative to accurately diagnose a potentially deadly tumor. Endoscopic ultrasound is helpful when working through a differential diagnosis of subepithelial lesions and can help identify which mucosal layer the lesion originates from, as well as the density of the lesion; however, surgical resection is the standard of care for the treatment of a resectable nonmetastatic GIST. For recurrent GISTs, metastatic disease, or GISTs not amendable to resection, tyrosine kinase inhibitors are frequently used, with imatinib being used in the first-line setting. A multimodal treatment approach is often necessary to increase the chances of a permanent cure.

Optical second-harmonic generation imaging for identifying gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors arising in the digest tract. It brings a challenge to diagnosis because it is asymptomatic clinically. It is well known that tumor development is often accompanied by the changes in the morphology of collagen fibers. Nowadays, an emerging optical imaging technique, second-harmonic generation (SHG), can directly identify collagen fibers without staining due to its noncentrosymmetric properties. Therefore, in this study, we attempt to assess the feasibility of SHG imaging for detecting GISTs by monitoring the morphological changes of collagen fibers in tumor microenvironment. We found that collagen alterations occurred obviously in the GISTs by comparing with normal tissues, and furthermore, two morphological features from SHG images were extracted to quantitatively assess the morphological difference of collagen fibers between normal muscular layer and GISTs by means of automated image analysis. Quantitative analyses show a significant difference in the two collagen features. This study demonstrates the potential of SHG imaging as an adjunctive diagnostic tool for label-free identification of GISTs.

Benefit of Continuation of Low-Dose Imatinib for Gastrointestinal Stromal Tumors despite Adverse Events with Regular-Dose Imatinib

Tyrosine kinase inhibitors (TKIs) such as imatinib improve the prognosis of patients with gastrointestinal stromal tumors (GISTs). However, treatment options for GISTs are still limited, and the continuation of TKIs is difficult due to adverse events in some cases. The effectiveness of low-dose imatinib is unclear. We report 2 cases to show effectiveness of low-dose imatinib in patients with adverse events. The first case is a male in his early 60s with a history of intestinal GIST resection who was diagnosed with recurrent GIST with peritoneal dissemination. He was started on low-dose imatinib (300 mg) because of a history of subconjunctival hemorrhage after receiving postoperative imatinib. Follow-up contrast-enhanced ultrasonography revealed that the tumors had shrunk in size and number after 2 months of treatment with 300-mg imatinib. He continued this treatment and showed partial response for 8 months. The second case is a female in her late 70s with rectal GIST who was treated with imatinib 400 mg. Due to a severe skin lesion, she changed her treatment to sunitinib 2 months after initiation. However, new metastasis in the liver was confirmed after 4 months of administration of sunitinib. She underwent surgical esection of the rectal tumor to reduce the volume. After the surgery, low-dose imatinib (300 mg) with oral steroids was adopted. Follow-up confirmed the absence of recurrence at the rectum and no increase in hepatic tumor size for 18 months. Aggressive treatment with low-dose imatinib instead of discontinuation or alteration of treatment may benefit patients with unresectable and postoperative GISTs with sensible mutation to imatinib.

Deep learning and radiomics to predict the mitotic index of gastrointestinal stromal tumors based on multiparametric MRI

Introduction

Preoperative evaluation of the mitotic index (MI) of gastrointestinal stromal tumors (GISTs) represents the basis of individualized treatment of patients. However, the accuracy of conventional preoperative imaging methods is limited. The aim of this study was to develop a predictive model based on multiparametric MRI for preoperative MI prediction.

Methods

A total of 112 patients who were pathologically diagnosed with GIST were enrolled in this study. The dataset was subdivided into the development (n = 81) and test (n = 31) sets based on the time of diagnosis. With the use of T2-weighted imaging (T2WI) and apparent diffusion coefficient (ADC) map, a convolutional neural network (CNN)-based classifier was developed for MI prediction, which used a hybrid approach based on 2D tumor images and radiomics features from 3D tumor shape. The trained model was tested on an internal test set. Then, the hybrid model was comprehensively tested and compared with the conventional ResNet, shape radiomics classifier, and age plus diameter classifier.

Results

The hybrid model showed good MI prediction ability at the image level; the area under the receiver operating characteristic curve (AUROC), area under the precision-recall curve (AUPRC), and accuracy in the test set were 0.947 (95% confidence interval [CI]: 0.927-0.968), 0.964 (95% CI: 0.930-0.978), and 90.8 (95% CI: 88.0-93.0), respectively. With the average probabilities from multiple samples per patient, good performance was also achieved at the patient level, with AUROC, AUPRC, and accuracy of 0.930 (95% CI: 0.828-1.000), 0.941 (95% CI: 0.792-1.000), and 93.6% (95% CI: 79.3-98.2) in the test set, respectively.

Discussion

The deep learning-based hybrid model demonstrated the potential to be a good tool for the operative and non-invasive prediction of MI in GIST patients.

Current surgical management of duodenal gastrointestinal stromal tumors

Duodenal gastrointestinal stromal tumors (D-GISTs) are uncommon mesenchymal tumors and are managed differently to common duodenal epithelial tumors. They may pose surgical challenges due to their unique but complex pancreaticoduodenal location of the gastrointestinal tract near the ampulla of Vater, pancreas, mesenteric blood vessels, biliary and pancreatic ducts. The surgical management of D-GISTs can be performed safely with good oncological outcomes provided an adequate resection margin can be achieved. The current surgical options of resectable primary D-GISTs varies with increasing complexity depending on the location, size and involvement of surrounding structures such as wedge resection with primary closure, segmental resection with small bowel anastomosis or radical pancreaticoduodenectomy. Laparoscopic approaches have been shown to be feasible and safe with good oncological outcomes in experienced hands. The minimally invasive techniques including robotic-assisted approach will likely increase in the future. D-GISTs have a prognosis comparable to gastric and other small bowel GISTs. However, the heterogeneity of different studies and the limited use of systemic tyrosine kinase inhibitor in the neoadjuvant and adjuvant settings may influence the overall survival of resected D-GISTs. The use of limited resection when condition allows is recommended due to lower surgical morbidity, less postoperative complications and better oncologic outcomes.

A multidisciplinary approach in the diagnostic challenge of GIST

Gastrointestinal stromal tumors (GISTs) are the most common malignant mesenchymal lesions of the gastrointestinal tract. They originate from the interstitial cells of Cajal and are characterized by overexpression of the tyrosine kinase receptor, protein product of c-KIT gene (KIT). In this retrospective study, conducted over a period of 10 years, we retrieved from our database, a total number of 57 patients, admitted and operated in the surgical department of ‘Sf. Pantelimon’ Emergency Clinical Hospital, Bucharest, for digestive tumors, histopathologically confirmed as GISTs. More than half of the cases presented as surgical emergencies and the tumors found during the surgical procedures, which proved to be GISTs, were sometimes difficult to differentiate from other mesenchymal tumors, both for the clinician and the pathologist. The diagnosis of GIST relies mostly on pathology and immunohistochemistry, but also on clinical and imagistic data. The most common emergencies were digestive hemorrhage (associated with gastric location), followed by intestinal obstruction (especially for the ileal localization). The largest dimensions corresponded to gastric location. For selected indications (upper digestive sites), upper digestive endoscopy approaches 100% sensitivity. This study focuses on diagnosis of GISTs sustained by both clinical and imagistic methods, along with histopathology and immunohistochemistry techniques, according to the World Health Organization 2019 criteria. Even though the differential diagnosis of these tumors is challenging, an interdisciplinary cooperation with a multiple approach increases the odds of a correct positive diagnosis.

Assessment of Systemic Inflammation and Nutritional Indicators in Predicting Recurrence-Free Survival After Surgical Resection of Gastrointestinal Stromal Tumors

Background

Recent studies have shown that the systemic inflammation and nutritional indicators are prognostic for a variety of malignancies. However, only limited data have so far demonstrated their usefulness in gastrointestinal mesenchymal tumors (GIST).

Methods

We retrospectively analyzed the data of GIST patients who underwent radical surgery in Beijing hospital from October 2004 to July 2018. The area under the receiver operating characteristic curve (AUC) was used to compare several commonly used inflammatory and nutritional indicators. The indicators with largest AUC were further analysis. Optimal cut-off values of those indicators in predicting recurrence-free survival (RFS) were determined. Kaplan-Meier curve and the time-dependent receiver operating characteristic (ROC) curve were used to assess the prognostic values. We then used univariate and multivariate Cox regression analyses to identify prognostic factors that were associated with RFS.

Results

In total, 160 patients who underwent surgery for GIST were included in the study. The median survival time was 34.5 months, with 1-, 3-, and 5-year RFS rates of 96.1%, 84.7%, and 80.8%, respectively. The inflammatory and nutritional indicators with largest AUC were Systemic immunoinflammatory Index (SII) and Geriatric Nutrition Risk Index (GNRI), reached 0.650 and 0.713, respectively. The optimal cutoff of GNRI and SII were 98.3, and 820.0, respectively. Univariate analysis showed that GNRI, SII, KI67, surgery method, tumor location, tumor size, and mitotic index were all significant prognostic indicators of RFS. After multivariate Cox analysis, independent prognostic factors for RFS in GIST included tumor location, mitotic index, tumor size, and GNRI (HR=2.802,95% CI: 1.045 to 7.515, p = 0.041). Besides, SII also tended to be associated with RFS (HR = 2.970, 95% CI: 0.946 to 9.326, p = 0.062).

Conclusions

High GNRI is an independent prognostic factor for RFS in GIST, while SII can be considered as a prognostic factor. GNRI and SII can be used as tools to evaluate the prognosis of patients before surgery, helping doctors to better treat high-risk patients.

CD11c-CD8 Spatial Cross Presentation: A Novel Approach to Link Immune Surveillance and Patient Survival in Soft Tissue Sarcoma

Checkpoint inhibitors are slowly being introduced in the care of specific sarcoma subtypes such as undifferentiated pleomorphic sarcoma, alveolar soft part sarcoma, and angiosarcoma even though formal indication is lacking. Proper biomarkers to unravel potential immune reactivity in the tumor microenvironment are therefore expected to be highly warranted. In this study, intratumoral spatial cross presentation was investigated as a novel concept where immune cell composition in the tumor microenvironment was suggested to act as a proxy for immune surveillance. Double immunohistochemistry revealed a prognostic role of direct spatial interactions between CD11c+ antigen-presenting cells (APCs) and CD8+ cells in contrast to each marker alone in a soft tissue sarcoma (STS) cohort of 177 patients from the Karolinska University Hospital (MFS p = 0.048, OS p = 0.025). The survival benefit was verified in multivariable analysis (MFS p = 0.012, OS p = 0.004). Transcriptomics performed in the TCGA sarcoma cohort confirmed the prognostic value of combining CD11c with CD8 (259 patients, p = 0.005), irrespective of FOXP3 levels and in a CD274 (PD-LI)-rich tumor microenvironment. Altogether, this study presents a histopathological approach to link immune surveillance and patient survival in STS. Notably, spatial cross presentation as a prognostic marker is distinct from therapy response-predictive biomarkers such as immune checkpoint molecules of the PD-L1/PD1 pathway.

KIT and PDGFRa mutational patterns in Sardinian patients with gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal malignancy of the gastrointestinal tract. We provide in the present article the molecular characterization of a series of primary GISTs in a cohort of Sardinian patients (Italy), with the aim to describe the patterns of KIT and PDGFRa mutations and the corresponding clinical features. Ninety-nine Sardinian patients with histologically-proven diagnosis of GIST were included in the study. Medical records and pathology reports were used to assess the demographic and clinical features of the patients and the disease at the time of the diagnosis. Formalin-fixed, paraffin-embedded tissue samples were retrieved for each case, and mutation analysis of the KIT and PDGFRa genes was performed. KIT and PDGFRa mutations were detected in 81.8% and 5% of the cases, respectively. The most common KIT mutation was W557_K558del in exon 11, while D842V in exon 18 was the most common PDGFRa genetic alteration; V561D was the only PDGFRa mutation found in exon 12. The global "wild-type" cases, with no mutations in either the KIT or PDGFRa genes, were 13 (13.1%). The mean survival of those patients was approximately 46.9 (±43.9) months. Globally, 86.9% of Sardinian patients with GIST had a KIT or PDGFRa mutation; the former were more frequent in comparison with other Italian cohorts, while PDGFRa mutations were rare. No statistical differences in survival between mutated and wild-type cases, and between KIT and PDGFRa mutated cases were detected in our study.

Clinical features and immunohistochemistry profile of biopsy-proven gastric gastrointestinal stromal tumor (GIST): a description of 5 years case series and literature review of GIST

Background

Gastrointestinal stromal tumor (GIST) was the most common mesenchymal tumor of the gastrointestinal tract predominately occurring in the stomach. Although GIST was a rare disease, it was considered to be a life-threatening malignancy.

Objective

To explore the current status of gastric GIST in Thai patients.

Method

The medical records of patients who were diagnosed with histologically proven gastric GIST from 2012 to 2016 in King Chulalongkorn Memorial Hospital were reviewed.

Results

Of 22 patients, there were 14 (63.6%) females and 8 (36.4%) males with the mean age of 62.6 ± 14.8 years. The average duration before the first presentation was 12 weeks. The initial symptoms were upper gastrointestinal bleeding (50.0%) followed by abdominal pain (31.8%). Tumor mostly located at the proximal part (fundus and cardia) in 20 (90.9%) patients. At the time of the diagnosis, three patients (13.6%) had distant metastasis. Of this group, 77.3% underwent surgical treatment.

Discussion

Although gastric GIST was an uncommon disease, early diagnosis and prompt treatment could save the lives of many patients.

The Use of Molecular Subtypes for Precision Therapy of Recurrent and Metastatic Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor in the digestive tract. Tyrosine kinase inhibitors (TKIs), represented by imatinib, sunitinib, and regorafenib, have become the main treatment for recurrent and metastatic GISTs. With the wide application of mutation analysis and the precision medicine, molecular characteristics have been determined that not only predict the prognosis of patients with recurrent and metastatic GISTs, but also are closely related to the efficacy of first-, second- and third-line TKIs for GISTs, as well as other TKIs. Despite the significant effects of TKIs, the emergence of primary and secondary resistance ultimately leads to treatment failure and tumor progression. Currently, due to the signal transmission of KIT/PDGFRA during onset and tumor progression, strategies to counteract drug resistance include the replacement of TKIs and the development of new drugs that are directed towards carcinogenic mutations. In addition, it is also the embodiment of precision medicine for GISTs to explore new carcinogenic mechanisms and develop new drugs relying on new biotechnology. Surgery can benefit specific patients but its major purpose is to diminish the resistant clones. However, the prognosis of recurrent and metastatic patients is still unsatisfactory. Therefore, it is worth paying attention to how to maximize the benefits for patients.

Hybrid Laparoscopic and Endoscopic Partial Gastrectomy for Ulcerated GIST: Surgical Technique with Video

INTRODUCTION

Gastrointestinal stromal tumors of the gastric cardia pose several technical difficulties to their resection because they are difficult to access, and they must be removed respecting oncological principles, and due to their proximity to the gastroesophageal junction, excessive removal of gastric tissue may cause deformation with gastric dysfunction, or gastroesophageal reflux.

METHOD

Hybrid laparoscopic endoscopic partial gastrectomy is a technique that avoids these problems making use of three principles. First the tumor is pinpointed, marked, and resected under combined laparoscopic and endoscopic control to assure that it is completely resected without compromising the structure of the gastroesophageal junction. Second, a dissection of the abdominal esophagus is performed as during a Nissen fundoplication in order to increase the distance between the tumor and the gastroesophageal junction. Third the lesser curvature of the stomach is dissected, and the terminal branches of the left gastric vessels are controlled from the gastric incisura to the gastroesophageal junction exposing the lesser curvature and the posterior wall of the stomach. The tumor is resected under endoscopic control, tangentially with an endoscopic stapler applied parallel to the lesser curvature similarly to a sleeve partial gastrectomy.

RESULTS

No abdominal drain is used, and a nasogastric tube is left in place for the first 24 h after surgery. The patient receives fluid diet on the first postoperative day, is discharged on the second postoperative day, and is followed up in the outpatient department for a week.

CONCLUSION

In this technical paper, the procedure is described in detail and demonstrated with video.

Anti-tumoral activity of single and combined regorafenib treatments in preclinical models of liver and gastrointestinal cancers

Regorafenib is a sorafenib-derived chemotherapy drug belonging to the multikinase inhibitor family. This agent effectively targets a wide range of tyrosine kinases involved in cancer biology, such as those implicated in oncogenesis, angiogenesis, and tumor microenvironment control. The beneficial effects of regorafenib in clinical trials of patients who suffer from advanced hepatocellular carcinoma (HCC), colorectal cancer (CRC) or gastrointestinal stromal tumors (GISTs) refractory to standard treatments led to regorafenib monotherapy approval as a second-line treatment for advanced HCC and as a third-line treatment for advanced CRC and GISTs. Multiple in vitro and in vivo studies have been performed over the last decade to reveal the molecular mechanisms of the favorable actions exerted by regorafenib in patients. Given the hypothetical loss of sensitivity to regorafenib in tumor cells, preclinical research is also searching for novel therapeutic approaches consisting of co-administration of this drug plus other agents as a strategy to improve regorafenib effectiveness. This review summarizes the anti-tumor effects of regorafenib in single or combined treatment in preclinical models of HCC, CRC and GISTs and discusses both the global and molecular effects that account for its anti-cancer properties in the clinical setting.

The cancer drug regorafenib exhibits a broad range of anti-tumor activities that could be enhanced by combination with other treatments. A team led by José L. Mauriz from the University of León, Spain, review the ways in which regorafenib, blocking several enzymes involved in cancer biology, has been shown to shrink tumors in different models of liver, colon and gastrointestinal cancer. Its mechanisms of action include blockade of new blood vessel formation, induction of cell death and modulation of the immune microenvironment. Research studies show that co-administration of regorafenib with other drugs directed at various molecular targets or immune pathways produces synergistic effects against cancer cells. The preclinical data highlights the potential of combination drug regimens to improve outcomes among patients eligible for regorafenib treatment.

Downregulation of lncRNA CCDC26 contributes to imatinib resistance in human gastrointestinal stromal tumors through IGF-1R upregulation

Imatinib is the first line of therapy for patients with metastatic or gastrointestinal stromal tumors (GIST). However, drug resistance limits the long-term effect of imatinib. Long non-coding RNAs (lncRNAs) are emerging as key players in regulating drug resistance in cancer. In this study, we investigated the association between lncRNA CCDC26 and IGF-1R in GIST and their involvement in drug resistance. Considering the key role of lncRNAs in drug resistance in cancer, we hypothesized that IGF-1R is regulated by lncRNAs. The expression of a series of reported drug resistance-related lncRNAs, including CCDC26, ARF, H19, NBR2, NEAT1, and HOTAIR, in GIST cells treated with imatinib H19 was examined at various time-points by qRT-PCR. Based on our results and published literature, CCDC26, a strongly down-regulated lncRNA following imatinib treatment, was chosen as our research target. GIST cells with high expression of CCDC26 were sensitive to imatinib treatment while knockdown of CCDC26 significantly increased the resistance to imatinib. Furthermore, we found that CCDC26 interacted with c-KIT by RNA pull down, and that CCDC26 knockdown up-regulated the expression of IGF-1R. Moreover, IGF-1R inhibition reversed CCDC26 knockdown-mediated imatinib resistance in GIST. These results indicated that treatments targeting CCDC26-IGF-1R axis would be useful in increasing sensitivity to imatinib in GIST.

Gastric gastrointestinal stromal tumors: clinical features and short- and long-term outcomes of laparoscopic resection

Introduction

Although minimally invasive techniques are currently recognized as effective and validated treatment for small gastric gastrointestinal stromal tumors (GISTs), the role of laparoscopy is not yet established, especially in the institutions that have less experience in minimally invasive surgery.

Aim

To evaluate the outcomes of laparoscopic treatment of gastric gastrointestinal stromal tumors compared to the results obtained in a group of patients treated with conventional surgery.

Material and methods

A retrospective analysis of data collected for a group of 68 patients treated for gastric GIST in the period from 2002 to 2017 was performed. Forty-six patients were treated laparoscopically (group 1) and 22 patients underwent conventional surgery (group 2). The analyzed medical data included clinical and pathomorphological features of removed tumors, perioperative parameters as well as short and long-term results of surgical treatment.

Results

Histopathological examination confirmed radical resection for all patients. No deaths were reported in the 30-day post-operative period. Patients in group 1 had significantly shorter length of hospital stay (3 vs. 9 days), less intra-operative blood loss (25 vs. 175 ml) and fewer perioperative complications (13% vs. 41%) compared to group 2. The mean post-operative follow-up was 57 months. During this period, four patients died for reasons unrelated to the primary disease. None of the patients who underwent a laparoscopic procedure had a recurrence of the tumor in the follow-up period.

Conclusions

Laparoscopy in the treatment of gastric GISTs has unquestionable advantages, including decreased blood loss, reduced risk of complications, and shorter hospital stay.

Colonic Gastrointestinal Stromal Tumor: A Population-Based Analysis of Incidence and Survival

Objectives

The incidence of gastrointestinal stromal tumors (GISTs) located in the colon is rare. Current studies mainly focus on case reports for colonic GISTs. Therefore, a population-based analysis was useful to guide the clinical treatment strategy.

Methods

The patients were selected from 2000 to 2015 based on Surveillance, Epidemiology, and End Results (SEER) database. Patients' demographics, tumor characteristics, incidence, treatment, and survival were retrieved for analysis.

Results

249 cases of colonic GISTs were collected. The male-female ratio was close to 1 : 1 (male 51.41%, female 48.59%). Most cases were Caucasians (70.28%), and African Americans accounted for 19.68%. Age of diagnosis ranged from 21 to 93 years with a median (mean) age of 67.5 (65.56). The incidence was rare, only 0.018 per 100,000. It had an annual percentage change (APC = -0.7728) without statistical significance (P = 0.5127) while the incidence of other GISTs increased from 2000 to 2015, with an annual percentage change of 3.9% (P = 0.0001). Surgery was associated with better prognosis whereas chemotherapy did not impact the survival rate.

Conclusion

Colonic GIST is a rare solid tumor, and the incidence is stable. The entity has a poorer prognosis than other GISTs. Surgery improved the survival rate, while chemotherapy did not.

Analysis of risk factors of gastrointestinal stromal tumors in different age groups based on SEER database

Objective: To investigate the risk factors affecting the survival of patients with gastrointestinal stromal tumors (GISTs) in different age groups. Methods: Information on 6089 GIST patients was screened from the Surveillance, Epidemiology, and End Results (SEER) database. Risk factor analysis was performed using a chi-square test (univariate analysis). Survival analysis was performed using the Kaplan-Meier method (log-rank test) and the COX proportional hazard model. p Value < .05 was considered statistically significant. Results: Analyzed statistically to reveal that in addition to tumor size, mitotic index, and primary location, age, gender, race, and surgical treatment also were independent risk factors for GISTs. Gender, race, and location of disease influenced the survival rate of patients, which was higher in the young group (≤60 years old) than the elderly group (>60 years). Risk factors such as primary location, tumor diameter, and mitotic index varied significantly between the different age groups. Conclusions: Age, gender, race, and surgical treatment are independent risk factors that influence the prognosis in patients with GISTs. Some risk factors affecting prognosis are age dependent.

Surgical treatment of gastric GIST with acute bleeding using laparoscopic sleeve gastrectomy: A report of two cases

In this report, we want to emphasize how a laparoscopic bariatric surgical procedure, in experienced hands, has shown to be a valid alternative for the hemorrhage control and the removal of a gastrointestinal tumor in a life-threatening situation.

Clinicopathological characteristics and prognosis of primary appendiceal stromal tumors

Background

Gastrointestinal stromal tumors (GISTs) account for less than 1% of all gastrointestinal tumors. The biological behaviors of GISTs vary from benign to malignant. GISTs are common in the stomach (55.6%) and small intestine (31.8%), but rarely in the rectum, colon (6%), and other sites (5.5%). Currently, the majority of published reports of primary appendiceal stromal tumors (PASTs) are case reports or case series.

Methods

The PASTs described in this study were identified from a literature review (23 cases) and our center (one case). The relationship between PAST gross types and clinicopathological factors was analyzed and summarized. At the same time, the study also analyzed the related risk factors and survival of PASTs and GISTs.

Results

Twenty-four cases of PASTs were compared with 254 cases of GISTs from our center. The results showed that there was a significant difference between the two groups in tumor size (P < 0.001), histological type (P = 0.013), CD34 expression (P < 0.001), and DOG-1 expression (P < 0.001). Disease-free survival (DFS) analysis of 11 cases of PASTs and 227 cases of GISTs found that a comparison of 3-year and 5-year DFS was not statistically significant (P = 0.894 and P = 0.846, respectively). In the DFS multivariate analysis, tumor mucosal ulceration, tumor size, and NIH risk classification were independent prognostic factors in 3-year and 5-year DFS.

Conclusion

In this study, there was no significance in the survival of patients with appendix and gastric stromal tumors, which we hypothesized to be associated with the low sample size and incomplete follow-up records. Based on this, we conclude that the prognosis of primary appendiceal stromal tumors may be better than gastric tumors, but this needs to be confirmed in further prospective studies.

Successful Laparoscopic Sleeve Gastrectomy in Emergency for a Gastric Gastrointestinal Stomal Tumor (GIST) with Acute Bleeding: A Case Report

BACKGROUND Gastrointestinal stomal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, and the stomach is the most commonly involved organ. Complete surgical resection with negative margins is the primary and only potentially curative treatment. Surgeon experience with minimally invasive gastric resections in addition to the tumor size and site has to be considered in the choice of laparoscopic or open surgical approach in order to remove the lesion. CASE REPORT A 67-year-old male patient with an history of gastric ulcer presented 2 days after an esophagogastroduodenoscopy with an incidental finding of a 30-mm gastric submucosal lesion that was not histologically defined (biopsies were taken), chest pain in association with hematemesis, and melena. An initial attempt to achieve endoscopic hemostasis with epinephrine injection was followed by the recurrence of the gastric bleeding until the presentation of hemorrhagic shock. An emergent laparoscopic sleeve gastrectomy was then performed for hemorrhage control. There were no intra- or postoperative major complications and the histological findings led to the diagnosis of a gastrointestinal stromal tumor (GIST). CONCLUSIONS Laparoscopic sleeve gastrectomy is a bariatric surgical treatment of morbid obesity. This report describes the application of a bariatric procedure in a life-threatening situation and illustrates how safe and effective it can be when performed by surgeons with excellent laparoscopic skills.

Management of hemorrhage in gastrointestinal stromal tumors: a review

Gastrointestinal stromal tumors (GISTs) are relatively common mesenchymal tumors. They originate from the wall of hollow viscera and may be found in any part of the digestive tract. The prognosis of patients with stromal tumors depends on various risk factors, including size, location, presence of mitotic figures, and tumor rupture. Emergency surgery is often required for stromal tumors with hemorrhage. The current literature suggests that stromal tumor hemorrhage indicates poor prognosis. Although the optimal treatment options for hemorrhagic GISTs are based on surgical experience, there remains controversy with regard to optimum postoperative management as well as the classification of malignant potential. This article reviews the biological characteristics, diagnostic features, prognostic factors, treatment, and postoperative management of GISTs with hemorrhage.

CCDC26 knockdown enhances resistance of gastrointestinal stromal tumor cells to imatinib by interacting with c-KIT

Accumulating evidence indicates that long noncoding RNAs (lncRNAs) are involved in diseases such as cancer. However, little is known about the role of lncRNAs in gastrointestinal stromal tumors (GIST). In the present study, we explored the biological function of the lncRNA coiled-coil domain-containing 26 (CCDC26) in imatinib resistance of GIST. We found that human GIST-882 cells with lower CCDC26 expression were less sensitive to imatinib compared with GIST-T1 cells with higher CCDC26 expression. CCDC26 expression decreased in a time-dependent manner in the presence of imatinib. Moreover, small interfering RNA (siRNA) knockdown of CCDC26 increased GIST cell sensitivity to imatinib. The RNA pull-down experiment showed that CCDC26 can interact with c-KIT and that CCDC26 knockdown can upregulate c-KIT expression. We also found that inhibiting c-KIT induced resistance to imatinib. Lastly, we proved that inhibiting c-KIT can reverse CCDC26 knockdown-mediated imatinib resistance in GIST. We suggest that CCDC26 knockdown can induce imatinib resistance in GIST cells by downregulating c-KIT expression. Our results provide a novel insight into imatinib resistance in GIST.

Surgical treatment of gastrointestinal stromal tumors of the stomach: current status and future perspective

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, with the majority found in the stomach. Surgical resection of the primary gastric GISTs with complete resection margin has been the forefront of curative treatment. The indications for surgical resection are usually related to symptomatic gastric GISTs at presentation. Primary gastric GISTs resection performed conventionally through an open surgery can now be frequently achieved by minimal invasive surgery with similar oncological outcome. Surgeon's selection of the type of surgical techniques such as open, laparoscopic and endoscopic resections depends on the site, size and local invasion of gastric GISTs to the adjacent organ. Similarly those factors dictate the extent of gastric resections in the form of wedge, partial or total gastrectomy. All these inherent tumor factors (size and mitotic index), patient factors (older age, male) and surgical factors (incomplete resection margin, tumor rupture or spillage) play an important role in stratifying the malignant potential risk of primary gastric GISTs and their chances of recurrence. The understanding of gene mutation driving the growth of GISTs and the discovery of tyrosine kinase inhibitors (TKIs) has altered the surgical management of advanced and metastatic GISTs. Multi-modal therapy incorporating the surgical resection of GISTs and utilizing the molecular targeted therapy in the adjuvant, neoadjuvant and palliative settings can offer optimal personalized outcome and prolong patient's overall survival (OS).