Review article: the biology, diagnosis and management of gastrointestinal stromal tumours

KIT-SNAP-tag/cell membrane chromatography model coupled with liquid chromatography-mass spectrometry for anti-GIST compound screening from Evodia rutaecarpa

Gastrointestinal mesenchymal tumors, as the most common mesenchymal tumors in the gastrointestinal tract, are adjuvantly treated with multi-targeted tyrosine kinase inhibitors, such as imatinib and sunitinib, but there are problems of drug resistance and complex methods of monitoring therapeutic agents. The pathogenesis of this disease is related to mutations in tyrosine kinase (KIT) or platelet-derived growth factor receptor α, an important target for drug therapy. In recent years, the screening of relevant tyrosine kinase inhibitors from traditional Chinese medicine has become a hotspot in antitumor drug research. In the current study, the KIT-SNAP-tag cell membrane chromatography (KIT-SNAP-tag/CMC) column was prepared with satisfying specificity, selectivity, and reproducibility by chemically bonding high KIT expression cell membranes to the silica gel surface using the SNAP-tag technology. The KIT-SNAP-tag/CMC-HPLC-MS two-dimensional coupling system was investigated using the positive drug imatinib, and the results showed that the system was a reliable model for screening potential antitumor compounds from complex systems. This system screened and identified three potential active compounds of evodiamine (EVO), rutaecarpin (RUT), and dehydroevodiamine (DEVO), which possibly target the KIT receptor, from the alcoholic extract of the traditional Chinese medicine Evodia rutaecarpa. Then, the KD values of the interaction of EVO, RUT, and DEVO with KIT receptors measured using nonlinear chromatography were 7.75 (±4.93) × 10-6, 1.42 (±0.71) × 10-6, and 2.34 (±1.86) × 10-6 mol/L, respectively. In addition, the methyl thiazolyl tetrazolium assay validated the active effects of EVO and RUT in inhibiting the proliferation of high KIT-expressing cells in the ranges of 0.1-10 µmol/L and 0.1-50 µmol/L, respectively. In conclusion, the KIT-SNAP-tag/CMC could be a reliable model for screening antitumor components from complex systems.

Comparing endoscopic ultrasonography and double contrast-enhanced ultrasonography in the preoperative diagnosis of gastric stromal tumor

BACKGROUND

This study was designed to perform a comparative analysis between endoscopic ultrasonography (EUS) and double contrast-enhanced ultrasonography (DCEUS) for the preoperative diagnosis of gastric stromal tumors (GSTs).

METHODS

A retrospective study was conducted involving 139 patients with histologically confirmed GSTs. All patients preoperatively underwent DCEUS and EUS. The pathology reports were treated as the baseline and were retrospectively compared with the findings of EUS and DCEUS.

RESULTS

Of the 139 lesions, 120 and 113 were correctly identified by DCEUS and EUS, respectively, with an accuracy of 86.3% and 81.3%. The results revealed an insignificant difference between these two methods (p = 0.189).

CONCLUSIONS

DCEUS can display not only the locations, sizes, shapes, borders, internal echoes, but also show the blood perfusion patterns of GSTs. It is a highly accurate, noninvasive, and convenient method to be used at the pre-treatment stage.

Artificial intelligence-assisted endoscopic ultrasound in the diagnosis of gastrointestinal stromal tumors: a meta-analysis

BACKGROUND AND AIMS

Endoscopic ultrasonography (EUS) is useful for the diagnosis of gastrointestinal stromal tumors (GISTs), but is limited by subjective interpretation. Studies on artificial intelligence (AI)-assisted diagnosis are under development. Here, we used a meta-analysis to evaluate the diagnostic performance of AI in the diagnosis of GISTs using EUS images.

METHODS

PubMed, Ovid Medline, Embase, Web of science, and the Cochrane Library databases were searched for studies based on the EUS using AI for the diagnosis of GISTs, and a meta-analysis was performed to examine the accuracy.

RESULTS

Overall, 7 studies were included in our meta-analysis. A total of 2431 patients containing more than 36,186 images were used as the overall dataset, of which 480 patients were used for the final testing. The pooled sensitivity, specificity, positive, and negative likelihood ratio (LR) of AI-assisted EUS for differentiating GISTs from other submucosal tumors (SMTs) were 0.92 (95% confidence interval [CI] 0.89-0.95), 0.82 (95% CI 0.75-0.87), 4.55 (95% CI 2.64-7.84), and 0.12 (95% CI 0.07-0.20), respectively. The summary diagnostic odds ratio (DOR) and the area under the curve were 64.70 (95% CI 23.83-175.69) and 0.950 (Q* = 0.891).

CONCLUSIONS

AI-assisted EUS showed high accuracy for the automatic endoscopic diagnosis of GISTs, which could be used as a valuable complementary method for the differentiation of SMTs in the future.

Risk factors for the failure of endoscopic resection of gastric submucosal tumors: a long-term retrospective case-control study

OBJECTIVE

Endoscopic resection (ER) is an effective treatment method for gastric submucosal tumors (G-SMTs), but endoscopic resection failure requires emergency surgery. The purpose of this study was to assess potential risk factors for endoscopic resection failure.

METHODS

A total of 1041 patients with G-SMT undergoing endoscopic resection were enrolled. Twenty-five patients in whom endoscopic resection failed, requiring a transition to surgery midway through the operation, were included in the failed group, and 1016 patients who received successful endoscopic resection were included in the successful endoscopic resection group. Baseline and lesion characteristics were recorded, and the differences in tumor characteristics and risk factors for resection failure of G-SMT were analyzed. Sensitivity analysis was performed to detect the stability of the indicator.

RESULTS

Of the 1041cases included, there were 25 cases (2.4%) of failed endoscopic resection. Binary logistic analysis showed that the independent risk factors included tumors originating from deep muscularis propria(OR = 14.42, 95% CI 4.47-46.52), size > 3 cm (OR = 7.75, 95% CI 2.64-22.70), exophytic growth pattern (OR = 4.98, 95% CI 1.62-15.29), endoscopist with less experience (OR = 5.99, 95% CI 1.07-12.19), and irregular borders (OR = 4.13, 95% CI 1.40-12.19). The stable risk factors were tumors size, tumor origin and growth pattern according to sensitivity analysis.

CONCLUSIONS

Tumors originating from the deep muscularis propria, tumor size > 3 cm, endoscopists with less experience, an exophytic growth pattern, and irregular boundaries were found to be independent risk factors for endoscopic resection failure. To reduce the risk of endoscopic resection failure, physicians should carefully evaluate G-SMT characteristics preoperative.

Complete response of advanced rectal gastrointestinal stromal tumors after imatinib treatment: A case report and literature review

RATIONALE

Patients with rectal gastrointestinal stromal tumors (GISTs) who achieve a complete response (CR) with imatinib therapy have rarely been reported in the literature. Moreover, no treatment guidelines have been established for rectal GIST patients with CR after imatinib treatment, warranting further studies.

PATIENT CONCERNS

A 51-year-old man presented to our outpatient clinic in October 2013 with complaints of difficulty to defecate and a change in stool characteristics. During digital rectal examination, a mass was palpated within 5 cm from the anal verge. Contrast-enhanced computed tomography revealed a 8.1 × 7.2-cm rectal mass with significant enhancement during the arterial phase.

DIAGNOSES

A diagnosis of GIST was established after conducting needle biopsy and immunohistochemistry staining.

INTERVENTIONS

Imatinib therapy (400 mg/d, oral administration) was immediately started. When the patient achieved clinical CR (cCR), the oncologist recommended the patient to continue imatinib treatment.

OUTCOMES

At 7 months after imatinib administration, the patient achieved cCR. As suggested by the oncologist, the patient continued to receive imatinib treatment after cCR. After 13 months, the patient spontaneously stopped imatinib. Finally, tumor recurrence was observed 7 months later.

LESSONS

Surgery remains the mainstay of treatment for advanced rectal GIST patients who achieve cCR after imatinib treatment. Close follow-up and continuous imatinib treatment are indicated in patients who cannot undergo surgery.

Effects of Endoscopic Submucosal Excavation With Non-Submucosal Injection on Stromal Tumors in Stomach

Background and Aim

Endoscopic submucosal excavation (ESE) is commonly used to treat gastrointestinal stromal tumors (GISTs), especially for tumor sizes within 2 cm; compared with the conventical ESE, the efficacy and safety of the no-submucosal injection (NSI) ESE remains unclear. The aim of this study was to assess the clinical efficacy and safety of NSI-ESE for gastric stromal tumors.

Methods

ESE was performed in 102 patients at our hospital between January 2018 and January 2020, and the clinical features, surgical outcomes, complications, cost of performance, pathological diagnosis, and risk classification were evaluated.

Results

All tumors were completely resected by endoscopic resection (ER), with a complete resection rate of 100%. It was achieved by ESE/EFTR (endoscopic full-thickness resection) in 49 cases with submucosal injection, and by ESE/EFTR in 53 cases with NSI-ESE. The mean surgical time in cases with submucosal injection was 25.86 ± 4.45 min, compared to the cases without submucosal injection (17.23 ± 3.47 min), and the difference was significant (p < 0.001); the exposure time of tumor, the time of complete excavation of tumor, procedure cost, and hospital stay in the NSI-ESE group were all lower than those cases with submucosal injection (p < 0.05). In the risk classification, 95 (93.1%) cases had a very low risk, 4 (4.0%) cases had a low risk, and 2 (2.0%) cases had a high risk. No recurrence or metastasis was observed during the follow-up period of 18 ± 6 months (range: 13–25 months).

Conclusions

NSI-ESE is a feasible, effective, and safe treatment for gastric GISTs; compared to the conventional ESE, NSI-ESE has the following advantages: it decreases procedure time, it lowers the risk of perforation, and it is cost-effective.

Diagnosis of gastric submucosal tumors and estimation of malignant risk of GIST by endoscopic ultrasound. Comparison between B mode and contrast-harmonic mode

BACKGROUND

standard B-mode EUS assessment and EUS-guided tissue acquisition present sub-optimal diagnostic yield in the differential diagnosis of gastric submucosal tumors (SMTs).

AIMS

to evaluate the performances of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) to differentiate gastric SMTs and predict malignancy risk of gastrointestinal stromal tumors (GIST).

METHODS

a retrospective analysis was performed retrieving consecutive patients with gastric SMTs who underwent EUS between 2009 and 2014. Patients with available EUS video recordings and histological diagnosis were included. De-identified videos were presented to experts who made a diagnosis on B-mode EUS and CH-EUS.

RESULTS

fifty-four patients (29 female, 64-year-old) were included. Final diagnoses were 40 GISTs (8 high-grade), 9 leiomyomas, 5 rare SMTs. The sensitivity, specificity, and accuracy of B-mode and CH-EUS for the differential diagnosis of GIST were 95.0% vs. 85.0%, 57.1% for both techniques, and 85.2% vs. 77.8%, respectively. The sensitivity, specificity, and accuracy of B-mode and CH-EUS for the estimation of the malignancy GISTs risk were 62.5% vs. 100%, 83.3% vs. 82.1%, and 78.9% vs. 86.1%, respectively.

CONCLUSIONS

CH-EUS showed better diagnostic performance than B-mode EUS in differentiating leiomyomas and risk stratification of GIST. When considering high-grade GISTs, the addition of CH-EUS allowed an improvement in diagnostic accuracy.

Targeted Therapies in Cancer: To Be or Not to Be, Selective

Development of targeted therapies in recent years revealed several nonchemotherapeutic options for patients. Chief among targeted therapies is small molecule kinase inhibitors targeting key oncogenic signaling proteins. Through competitive and noncompetitive inhibition of these kinases, and therefore the pathways they activate, cancers can be slowed or completely eradicated, leading to partial or complete remissions for many cancer types. Unfortunately, for many patients, resistance to targeted therapies, such as kinase inhibitors, ultimately develops and can necessitate multiple lines of treatment. Drug resistance can either be de novo or acquired after months or years of drug exposure. Since resistance can be due to several unique mechanisms, there is no one-size-fits-all solution to this problem. However, combinations that target complimentary pathways or potential escape mechanisms appear to be more effective than sequential therapy. Combinations of single kinase inhibitors or alternately multikinase inhibitor drugs could be used to achieve this goal. Understanding how to efficiently target cancer cells and overcome resistance to prior lines of therapy became imperative to the success of cancer treatment. Due to the complexity of cancer, effective treatment options in the future will likely require mixing and matching these approaches in different cancer types and different disease stages.

Minimally Invasive Approach to Gastric GISTs: Analysis of a Multicenter Robotic and Laparoscopic Experience with Literature Review

Simple Summary

Gastrointestinal stromal tumors (GISTs) represent about 1–3% of all gastrointestinal malignancies, of which 50–60% are gastric GISTs (GGs). To the date, surgery represents the best therapeutic option, and the robotic gastric surgery could gain an important role, overcoming many laparoscopic drawbacks. The aim of this study is to evaluate safety and effectiveness of minimally invasive surgery (MIS) for GGs, reporting 10-year experience of three different centers. We included a population of 81 patients who underwent MIS approaches (36 laparoscopy vs. 45 robotic surgery). Seventy-two (72) patients were enrolled in a follow-up program to evaluate the long-term oncological outcomes. Furthermore, we discussed some technical notes and also we analyzed the operative and peri-operative outcomes. In conclusion, our results suggest that the robotic approach might be a suitable treatment, especially for GISTs >5 cm, even located in unfavorable places, despite longer operative time and costs than laparoscopic approach.

Abstract

Background: Gastrointestinal stromal tumors (GISTs) are most frequently located in the stomach. In the setting of a multidisciplinary approach, surgery represents the best therapeutic option, consisting mainly in a wedge gastric resection. (1) Materials and methods: Between January 2010 to September 2020, 105 patients with a primary gastrointestinal stromal tumor (GISTs) located in the stomach, underwent surgery at three surgical units. (2) Results: A multi-institutional analysis of minimally invasive series including 81 cases (36 laparoscopic and 45 robotic) from 3 referral centers was performed. Males were 35 (43.2%), the average age was 66.64 years old. ASA score ≥3 was 6 (13.3%) in the RS and 4 (11.1%) in the LS and the average tumor size was 4.4 cm. Most of the procedures were wedge resections (N = 76; 93.8%) and the main operative time was 151 min in the RS and 97 min in the LS. Conversion was necessary in five cases (6.2%). (3) Conclusions: Minimal invasive approaches for gastric GISTs performed in selected patients and experienced centers are safe. A robotic approach represents a useful option, especially for GISTs that are more than 5 cm, even located in unfavorable places.

Aurora kinase A (AURKA) promotes the progression and imatinib resistance of advanced gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumor (GIST) is a common tumor that originates from the alimentary system mesenchyme. Compared to typical gastrointestinal carcinomas, GISTs exhibit unique malignant behaviors. Bioinformatic tools and subsequent experiments were applied to investigate novel targets involved in GIST progression and imatinib resistance.

METHODS

Differences in gene expression profiles between advanced and nonadvanced GISTs were comprehensively analyzed based on the Gene Expression Omnibus (GEO) dataset GSE136755. A protein-protein interaction (PPI) network was constructed to identify the potential target gene. Gene set enrichment analysis (GSEA) was used to elucidate relevant biological events related to the target gene based on the GSE47911 dataset. Subsequently, immunohistochemistry and Kaplan-Meier analysis were performed to validate the prognostic value of the target gene in GISTs. Overexpression of the target gene was conducted to analyze its function in the proliferation, apoptosis, and imatinib resistance of GIST/T1 cells.

RESULTS

In the current study, a total of 606 differentially expressed genes (DEGs) were screened based on the GSE136755 dataset, and the upregulated DEGs in advanced GISTs were mainly involved in cell division through functional annotations. The intersecting hub gene, Aurora kinase A (AURKA), was identified by degree and bottleneck algorithms. GSEA revealed that AURKA was involved in cell cycle-related biological processes. Analysis of the Oncomine and GEPIA databases revealed a pattern of elevated AURKA expression in most human malignances. Clinical assays demonstrated that AURKA could be an independent prognostic factor for GISTs. Additionally, overexpression of AURKA was experimentally demonstrated to promote cell proliferation, inhibit cell apoptosis, and enhance imatinib resistance in GIST/T1 cells.

CONCLUSIONS

These findings indicated that overexpression of AURKA promoted GIST progression and enhanced imatinib resistance, implying that AURKA is a potential therapeutic target for GISTs.

Coexistence of gastric cancer and gastric GIST with intra-tumor bleeding: successful embolization with subsequent total gastrectomy

Background

Gastrointestinal stromal tumor (GIST) is a rare tumor, however, simultaneous development of gastric cancer and gastric GIST has been documented more frequently in recent years. Rupture of gastric GIST is even more rare and occurred in 7% of all GISTs. Although ruptured GIST might be occasionally difficult to be managed by endoscopy, transcatheter arterial embolization (TAE) was reported to control bleeding from GIST effectively. We report herein a case of coexistence of gastric cancer and gastric GIST with progressing intra-tumor bleeding managed successfully by TAE and review the clinicopathological characteristics of this rare condition reported previously in the Japanese literature.

Case presentation

A 75-year-old woman with dyspnea and systemic edema was diagnosed as simultaneous occurrence of gastric cancer (histopathologically detected tubular adenocarcinoma pT2N1M0 fStageIIA) and gastric GIST (65 × 92 mm in diameter at the anterior wall of the fornix) with intra-tumor hemorrhage. Perceiving the progress of bleeding from tumor growth and exacerbating anemia, TAE of left gastric artery was performed. Then remission of anemia has been obtained, the patient underwent an elective radical surgery.

Conclusions

Simultaneous occurrence of gastric cancer and gastric GIST was speculated to be more common. TAE for ruptured GIST may be effective for hemostasis and reduction of tumor burden, which could facilitate minimal invasive surgery.

LncRNA-HOTAIR activates autophagy and promotes the imatinib resistance of gastrointestinal stromal tumor cells through a mechanism involving the miR-130a/ATG2B pathway

Gastrointestinal stromal tumors (GISTs) are common neoplasms of the gastrointestinal tract that can be treated successfully using C-kit target therapy and surgery; however, imatinib chemoresistance is a major barrier to success in therapy. The present study aimed to discover alternative pathways in imatinib-resistant GISTs. Long noncoding RNAs (lncRNAs) are newly discovered regulators of chemoresistance. Previously, we showed that the lncRNA HOTAIR was upregulated in recurrent GISTs. In this study, we analyzed differentially expressed lncRNAs after imatinib treatment and found that HOTAIR displayed the largest increase. The distribution of HOTAIR in GISTs was shifted from nucleus to cytoplasm after imatinib treatments. The expression of HOTAIR was validated as related to drug sensitivity through Cell Counting Kit-8 assays. Moreover, HOTAIR was associated strongly with cell autophagy and regulated drug sensitivity via autophagy. Mechanistically, HOTAIR correlated negatively with miRNA-130a in GISTs. The downregulation of miRNA-130a reversed HOTAIR-small interfering RNA-induced suppression of autophagy and imatinib sensitivity. We identified autophagy-related protein 2 homolog B (ATG2B) as a downstream target of miR-130a and HOTAIR. ATG2B downregulation reversed the effect of pEX-3-HOTAIR/miR-130a inhibitor on imatinib sensitivity. Finally, HOTAIR was shown to influence the autophagy and imatinib sensitivity of GIST cells in mouse tumor models. Our results suggested that HOTAIR targets the ATG2B inhibitor miR-130a to upregulate the level of cell autophagy so that promotes the imatinib resistance in GISTs.

Endoscopic or laparoscopic resection for small gastrointestinal stromal tumors: a cumulative meta-analysis

Background

Despite the recent large number of studies comparing endoscopic and laparoscopic resection for small gastrointestinal stromal tumors (GISTs) (diameter ≤ 5 cm), the results remain conflicting. The objective of this work was to perform a cumulative meta-analysis to assess the advantages and disadvantages of endoscopic resection vs. laparoscopic resection.

Methods

The meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We searched medical databases up to January 2020. Meta-analytical random or fixed effects models were used in pooled analyses. Meta-regression, cumulative meta-analyses, and subgroup analyses were performed to improve the accuracy of the conclusion. Sensitivity analyses were applied to assess the robustness of the results.

Results

A total of 12 cohort studies with 1383 participants comparing endoscopic resection and laparoscopic resection were identified, while three cohort studies with 167 participants comparing endoscopic resection and laparoscopic and endoscopic cooperative surgery were found. We found that endoscopic resection had shorter operation times (weighted mean difference [WMD] = –27.1 min, 95% confidence interval [CI]: –40.8 min to –13.4 min) and lengths of hospital stay (WMD = –1.43 d, 95% CI: –2.31 d to –0.56 d) than did laparoscopic resection. The results were stable and reliable. There were no significant differences in terms of blood loss, hospitalization costs, incidence of complications or recurrence rates. For tumor sizes 2 – 5 cm, endoscopic resection increased the risk of positive margins (relative risk [RR] = 5.78, 95% CI: 1.31 – 25.46). Although operation times for endoscopic resection were shorter than those of laparoscopic and endoscopic cooperative surgery (WMD = –41.03 min, 95% CI: –59.53 min to –22.54 min), there was a higher incidence of complications (RR = 4.03, 95% CI: 1.57 – 10.34).

Conclusions

In general, endoscopic resection is an alternative method for gastric GISTs ≤ 5 cm. Laparoscopic and endoscopic cooperative surgery may work well in combination. Further randomized controlled trials are recommended to validate or update these results.

Gastrointestinal stromal tumors (GIST): a proposal of a "CT-based predictive model of Miettinen index" in predicting the risk of malignancy

PURPOSE

To identify the predictors of malignancy on CT for the evaluation of gastrointestinal stromal tumors (GIST) by correlating CT findings with the mitotic index in order to propose a "CT-based predictive model of Miettinen index."

METHODS

One radiologist and one resident in radiology with 14- and 4-year experience in oncological field reviewed the CT findings of 42 patients by consensus, with respect to lesion site, size, contour, tumor growth pattern, enhancing pattern, degree of enhancement of tumor, percentage of tumor necrosis, mesenteric fat infiltration, ulceration, calcification, regional lymphadenopathy, direct invasion to adjacent organs, and distant metastasis. All parameters were correlated with the mitotic index evaluated at histopathological analysis following surgery. Normality of variables was evaluated using Shapiro-Wilk test. Pearson's correlation test was used to assess the interaction between variables. The diagnostic accuracy percentage of tumor necrosis was measured by receiver operating characteristic (ROC) analysis for detecting whether the number of mitosis per 50 high-power fields was > 5.

RESULTS

A significant statistical correlation was found between percentage of tumor necrosis and the mitotic index (p < 0.005), dimension, and location of the tumor.

CONCLUSION

CT could be an accurate technique in the prediction of malignancy of GIST in a CT risk assessment system, based on the location of the tumor, its size, and the percentage of tumor necrosis.

The prognostic value of gender in gastric gastrointestinal stromal tumors: a propensity score matching analysis

Background

Gastrointestinal stromal tumors (GISTs) of the stomach are the most common GISTs. The risk, incidence, and outcome of cancer are different between the sexes. Whether gender is related to the prognosis of gastric stromal tumors is unclear. Therefore, this study aims to explore the relationship between gender and gastric GIST prognosis.

Methods

Data from gastric GIST patients were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was performed to reduce confounding factors, and the clinicopathological features and prognosis of GIST patients were comprehensively evaluated.

Results

There were 512 male patients and 538 female patients with gastric GIST. The gender of gastric GIST patients was associated with marital status, surgical treatment, tumor size, and mitotic index (P < 0.05). The Kaplan-Meier analysis and log-rank test revealed that male patients had a higher mortality rate than female patients (P = 0.0024). After matching all the potential confounding factors, the survival of the female gastric GIST patients was better than that of the male gastric GIST patients (P = 0.042). Cox regression analysis revealed that gender was an independent risk factor for overall survival. The risk of death was higher for males than for females (HR 1.677, 95% CI 1.150–2.444, P = 0.007).

Conclusion

Gender could be a prognostic factor for gastric GIST survival, and male patients had a higher risk of death.

Clinical outcomes of tumor bleeding in duodenal gastrointestinal stromal tumors: a 20-year single-center experience

BACKGROUND

Duodenal gastrointestinal stromal tumors (GISTs) are rare, and reports on duodenal GIST bleeding are few. We analyzed the risk factors and clinical outcomes of hemorrhagic duodenal GISTs and compared them with those of gastric GISTs.

METHODS

Primary duodenal GISTs surgically diagnosed between January 1998 and December 2017 were retrospectively reviewed. Furthermore, patients with duodenal GIST were compared with those with primary gastric GIST histopathologically diagnosed between January 1998 and May 2015 using previously published data.

RESULTS

Of the 170 total patients with duodenal GISTs, 48 (28.2%) exhibited tumor bleeding. Endoscopic intervention, embolization, and non-interventional conservative treatment were performed for initial hemostasis in 17, 1, and 30 patients, respectively. The 5-year survival rate was 81.9% in the bleeding group and 89.4% in the non-bleeding group (P = 0.495). Multivariate analysis showed that p53 positivity was a significant risk factor for duodenal GIST bleeding (hazard ratio [HR] 2.781, P = 0.012), and age ≥ 60 years (HR 3.163, P = 0.027), a large maximum diameter (comparing four groups: < 2, 2-5, 5-10, and ≥ 10 cm), and mitotic count ≥ 5/high-power field (HPF) (HR 3.265, P = 0.032) were risk factors for overall survival. The incidence of bleeding was significantly higher in duodenal GISTs than in gastric GISTs (28.2% vs. 6.6%, P < 0.001), and the re-bleeding rate after endoscopic hemostasis was also higher in duodenal GISTs than in gastric GISTs (41.2% vs. 13.3%, P = 0.118).

CONCLUSION

In patients with duodenal GIST with old age, large tumor diameter, and mitotic count ≥ 5/HPF, a treatment plan should be established in consideration of the poor prognosis, although tumor bleeding does not adversely affect the prognosis. Duodenal GISTs have a higher incidence of tumor bleeding and re-bleeding rate after endoscopic hemostasis than gastric GISTs.

Endoscopic Removal of Gastrointestinal Stromal Tumors in the Stomach: A Single-Center Experience

BACKGROUND AND AIMS

Endoscopic removal of GISTs (gastrointestinal stromal tumors) is recently recognized, but less is known about its efficacy and safety. This study is aimed at assessing the feasibility, clinical efficacy, and safety of the endoscopic removal of gastric GISTs.

PATIENTS AND METHODS

Endoscopic removal (ER) of GISTs was performed in 134 patients at our hospital between January 2015 and January 2019. The clinical features, surgical outcomes, complications, pathological diagnosis, and risk classification were evaluated retrospectively.

RESULTS

ER was successful in 131 cases (98%), including 58 by ESD (endoscopic submucosal dissection), 43 by ESE (endoscopic submucosal excavation), 25 by EFTR (endoscopic full-thickness resection), and 5 by STER (submucosal tunneling endoscopic resection). In addition, GISTs of two cases were resected using LECS (laparoscopic and luminal endoscopic cooperative surgery) for the extraluminal and intraluminal growth pattern. The average tumor size was 1.89 ± 1.25 cm (range: 0.5-6.0 cm). Of these patients, 26 cases had a large tumor size (range: 2.0-6.0 cm), and endoscopic removal was successful in all of them. During the procedure, endoclips were used to close the perforation in all cases, without conversion to open surgery. The average length of hospital stay was 5.50 ± 2.15 days (range: 3-10 days). In the risk classification, 106 (79.7%) were of a very low risk, 25 (18.8%) of a low risk, and 2 (1.5%) of a moderate risk. The moderate-risk cases were treated with imatinib mesylate after ER. No recurrence or metastasis was observed during the follow-up period of 23 ± 8 months (range: 3-48 months).

CONCLUSIONS

The endoscopic treatment is feasible, effective, and safe for gastric GISTs, and individualized choice of approaches is recommended for GISTs.

Clinical outcomes of upper gastrointestinal bleeding in patients with gastric gastrointestinal stromal tumor

BACKGROUND

Upper gastrointestinal bleeding (UGIB) is one of the major manifestations of gastrointestinal stromal tumor (GIST) of the stomach. Several studies have reported that GIST bleeding is associated with poor prognosis. However, only case reports have reported hemostasis modalities for treating hemorrhagic gastric GIST. To identify clinical outcome of gastric GIST bleeding, we analyzed risk factors and prognosis of hemorrhagic GIST evaluating hemostasis methods.

METHODS

Total 697 patients histopathologically diagnosed with primary gastric GIST between January 1998 and May 2015 were enrolled to the study, retrospectively.

RESULTS

Of 697 total patients, 46 (6.6%) patients had UGIB. Endoscopic intervention, transarterial embolization, or surgical intervention was performed for initial hemostasis in 15, 2, and 1, respectively. Over a median of 68 months of follow-up, 16 patients in bleeding group and 88 patients in non-bleeding group died; the 5-year survival rate was 79.4% in bleeding group and 91.8% in non-bleeding group (p = 0.004). Multivariate analysis showed that significant risk factors for gastric GIST bleeding included the maximal tumor diameter > 5 cm and Ki-67 positivity. Age ≥ 60 [hazard ratio (HR) = 8.124, p = 0.048], necrosis (HR = 5.093, p = 0.027), and bleeding (HR 5.743, p = 0.034) were significant factors for overall survival of gastric GIST patients.

CONCLUSIONS

Bleeding risk of gastric GIST was higher when tumor had diameter > 5 cm or Ki-67 positivity. In addition, tumor bleeding, necrosis, and age ≥ 60 years were associated with poor overall survival. Endoscopic intervention can be considered as an effective method for initial hemostasis of hemorrhagic gastric GIST.

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.

Value of contrast-enhanced harmonic endoscopic ultrasonography in differentiating between gastrointestinal stromal tumors: A meta-analysis

OBJECTIVE

Contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) is a valuable device to diagnose and determine the malignant potential of gastrointestinal stromal tumors (GIST) as early as possible when making clinical therapeutic decisions. This study aimed to estimate the ability of CH-EUS to discriminate between GIST and benign submucosal lesions (SML) and to predict their malignant potential.

METHODS

PubMed, MEDLINE, EMBASE, the Web of Science, and Cochrane Central Register of Controlled Trials databases were screened. Using the data provided in the literatures, 2 × 2 tables were constructed to obtain the pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. A receiver operating characteristic (ROC) curve was generated and the area under the ROC curve (AUROC) was calculated.

RESULTS

Four studies with a total of 187 patients were identified to evaluate the value of CH-EUS in discriminating between GIST and benign SML. The pooled sensitivity, specificity, and AUROC were 89% (95% CI 0.82-0.93), 82% (95% CI 0.66-0.92), and 0.89, respectively. Five studies including 143 patients were analyzed to assess the accuracy of CH-EUS in determining the malignant potential of GIST. The pooled sensitivity, specificity, and AUROC curve of CH-EUS were 96% (95% CI 0.90-0.99), 53% (95% CI 0.40-0.66), and 0.92, respectively.

CONCLUSIONS

CH-EUS is a safe, noninvasive method that can distinguish between GIST and benign subepithelial lesions and to predict their malignant potential to a certain extent. Large-scale, multicenter prospective studies are needed in the future.

Clinicopathologic Characteristics and Optimal Surgical Treatment of Duodenal Gastrointestinal Stromal Tumor

BACKGROUND

The clinicopathologic characteristics of duodenal gastrointestinal stromal tumor (GIST) were unclear and the optimal surgical procedure for duodenal GIST remains poorly defined. We aimed to analyze clinicopathological characteristics, survival outcomes based on the surgical procedure, and recommend optimal surgical treatment for duodenal GIST.

METHODS

From July 2000 to April 2017, 118 patients with localized duodenal GIST underwent curative surgical resection at a single institution. We retrospectively reviewed the clinicopathological characteristics and survival outcomes.

RESULTS

The 5-year overall survival (OS) and disease-free survival (DFS) rates were 94.9 and 79.2%, respectively. On multivariate analysis, the mitotic count was a statistically significant prognostic factor for DFS. Limited resection (LR) was performed in 20 patients with GIST in the first or fourth portion of the duodenum. Both LR and pancreaticoduodenectomy (PD) were performed in 98 patients with GIST in second or third portion of the duodenum. The patients in the LR group had less late complications than in the PD group and no postoperative newly developed diabetes mellitus. The minimally invasive LR (MI-LR) group had a shorter duration of surgery and shorter length of postoperative hospital stay.

CONCLUSION

LR is a feasible and effective surgical treatment for patients with small-sized and antimesenteric-sided duodenal GIST in terms of late complications and postoperative diabetic complications. MI-LR has better perioperative outcomes than open LR. Therefore, we should consider MI-LR as an optimal surgical treatment for selected patients with duodenal GIST.

Simultaneous occurrence of splenic diffuse large B cell lymphoma and gastrointestinal stromal tumor in the stomach: a case report

Background

Although the primary malignant spleen tumor is relatively rare, lymphoma is the most common splenic malignancy. It can have quite different clinical manifestations that usually lead to relatively poor outcomes, and thus early and accurate diagnosis are of utmost importance.

Case presentation

The present study reports a case of a 67-year-old female with high fever, abnormal spleen (diagnosed by PET/CT) and no obvious lymph node enlargement. After being subjected to splenectomy, the patient was diagnosed with splenic diffuse large B cell lymphoma coexisting with gastrointestinal stromal tumor in the stomach.

Conclusions

To our knowledge, splenic lymphoma accompanied by gastrointestinal stromal tumor in the stomach is rarely reported. This case report discusses the diagnosis and case management of a patient referring to the existing literature.

Comparison of short- and long-term outcomes of laparoscopic vs open resection for gastric gastrointestinal stromal tumors

AIM

To compare the short- and long-term outcomes of laparoscopic (LR) vs open resection (OR) for gastric gastrointestinal stromal tumors (gGISTs).

METHODS

In total, 301 consecutive patients undergoing LR or OR for pathologically confirmed gGISTs from 2005 to 2014 were enrolled in this retrospective study. After exclusion of 77 patients, 224 eligible patients were enrolled (122 undergoing LR and 102 undergoing OR). The demographic, clinicopathologic, and survival data of all patients were collected. The intraoperative, postoperative, and long-term oncologic outcomes were compared between the LR and OR groups following the propensity score matching to balance the measured covariates between the two groups.

RESULTS

After 1:1 propensity score matching for the set of covariates including age, sex, body mass index, American Society of Anesthesiology score, tumor location, tumor size, surgical procedures, mitotic count, and risk stratification, 80 patients in each group were included in the final analysis. The baseline parameters of the two groups were comparable after matching. The LR group was significantly superior to the OR group with respect to the operative time, intraoperative blood loss, postoperative first flatus, time to oral intake, and postoperative hospital stay (P < 0.05). No differences in perioperative blood transfusion or the incidence of postoperative complications were observed between the two groups (P > 0.05). No significant difference was found in postoperative adjuvant therapy (P = 0.587). The mean follow-up time was 35.30 ± 26.02 (range, 4-102) mo in the LR group and 40.99 ± 25.07 (range, 4-122) mo in the OR group with no significant difference (P = 0.161). Survival analysis showed no significant difference in the disease-free survival time or overall survival time between the two groups (P > 0.05).

CONCLUSION

Laparoscopic surgery for gGISTs is superior to open surgery with respect to intraoperative parameters and postoperative outcomes without compromising long-term oncological outcomes.

Concomitant stromal tumor and early cancer of the stomach: What should be done?

Concomitant gastric stromal tumor (GST) and gastric cancer (GC) is uncommon; even more uncommon is a concomitant GST and early stage GC (EGC). Tumor resection by endoscopic submucosal dissection (ESD) for concomitant GST and EGC has not been reported. We sought to define the clinical importance of detection of concomitant GST and EGC during the first esophagogastroduodenoscopy (EGD), and compare the clinical outcomes of ESD versus radical surgery for the treatment of concomitant GST and EGC. Our investigation was a retrospective cohort study. Patients with concomitant GST and EGC who underwent ESD or radical surgery were enrolled at the university-affiliated hospital from January 2005 to January 2015. The detection rate of concomitant GST and EGC during the first EGD was 3/25 (12%). Among 25 patients, 14 underwent ESD and 11 underwent surgery. Mean operation time and hospital stay were significantly shorter in the ESD group than the surgery group. There were no significant differences in terms of rates of en bloc resection, complete resection, and early complications. Late complications were more common in the surgery group than in the ESD group. The median follow-up duration was 58.9 months. Three- or 5-year overall survival rates were 100% for both groups and no patient died of EGC and GST. There was no local recurrence in the 2 groups; however, 3 metachronous EGC lesions were found during the follow-up period in the ESD group as follows: the simultaneous occurrence of GST and EGC was uncommon; the detection rate of concomitant GST and EGC was very low at the first EGD; and ESD appeared to be a safe, efficient, and popular treatment option for concomitant GST and EGC, that met the ESD absolute indication, and the outcomes were comparable to those achieved with surgery.

Cytohistological and immunohistochemical characteristics of spindle-shaped mesenchymal neoplasms occurring in the gastrointestinal tract

The purpose of the present review is to analyze the cytohistological and immunohistochemical characteristics of spindle-shaped mesenchymal gastrointestinal neoplams (MGNs), a group of unusual neoplastic conditions with different biological behavior. These tumors exhibit clinical pictures strictly related to the site of origin and dimensions, even if they appear generally with an intramural localization. This latter point may suggest an useful application of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), mainly followed by the cell-block procedure (CBP) in the differential diagnostic approach. First of all, we discuss the most common entity of MGNs represented by gastrointestinal stromal tumors (GISTs), analyzing the morphologic characteristics and stressing the strength of immunohistochemical algorithm for diagnostic purposes. Successively, we have reported the less common group of spindle-shaped MGNs comprehensive of those arising elsewhere the soft tissues, such as leiomyomas, leiomyosarcomas, schwannomas, inflammatory myofibroblastic tumor and intra-abdominal desmoid fibromatosis. Finally, very uncommon spindle-shaped MGNs, like clear cell, follicular dendritic cell, undifferentiated pleomorphic and radiation-induced sarcomas as well as spindle cell dedifferentiated liposarcomas, have been briefly mentioned.

A Foregut Duplication Cyst of the Stomach in Association with a Gastrointestinal Stromal Tumor and a Leiomyoma: A Case Report

Objectives. Duplication cysts are rare benign lesions usually arising in the gastrointestinal tract. We report a case of a 52-year-old woman with an incidental gastric mass found on computed tomography during a pregraft workup for a familial cardiomyopathy. Methods. The mass was completely excised by partial gastrectomy and gross examination revealed a cystic lesion containing two small solid nodules in its wall. Microscopic evaluation and immunohistochemistry study were performed to further characterize the cyst and the nodules. A comprehensive literature review of the NCBI database PubMed was also carried out. Results. While the cyst was diagnosed as a foregut duplication cyst, the solid nodules proved to be concomitant gastrointestinal stromal tumor (GIST) and leiomyoma. Both morphologic features and immunohistochemistry stains, including CD117, smooth muscle actin, and CD34 supported the diagnosis. Clinical course was benign and the patient had no clinical evidence of relapse ten months following the surgical procedure. The literature search did not reveal any other published case of a foregut duplication cyst presenting in combination with a GIST and a leiomyoma. Conclusions. To our knowledge, this is the first case of a composite lesion comprising a foregut duplication cyst of the stomach along with a leiomyoma and a GIST.

A retrospective study on the safety, diagnostic yield, and therapeutic effects of endoscopic unroofing for small gastric subepithelial tumors

BACKGROUND AND AIMS

Accurate diagnosis of small gastric subepithelial tumors (SETs) is essential to assess their malignant potential. Endoscopic unroofing has been reported to yield sufficient tissue samples for histologic evaluation. This study aimed to evaluate the safety, diagnostic yield, and potential therapeutic effects of this technique over time.

METHODS

This retrospective analysis of prospectively collected clinical data identified patients who underwent endoscopic unroofing at the Medical University of Vienna from January 2003 to December 2012. Demographic data, indications for endoscopic unroofing, intraprocedural adverse events, hospital stay, histologic results, and follow-up procedures were reviewed.

RESULTS

A total of 14 patients (7 men; 7 women; median age, 70 years; range, 51-95 years) underwent endoscopic unroofing of 14 gastric SETs with a mean diameter of 26 ± 13 mm at EUS. In 9 of 14 cases, endoscopic unroofing was done exclusively for diagnostic purposes; in the remaining cases, it was performed with therapeutic intent because of bleeding from the gastric SETs. Unroofing was technically successful in 13 of 14 cases and revealed 8 cases of GI stromal tumor (GIST) and 1 case each of leiomyoma, fibroid polyp, glomus tumor, pancreatic rest, and nondiagnostic material at histology. Intraprocedural bleeding was the only adverse event (4 cases) and could be managed endoscopically. A follow-up EUS was available (median, 8 months) for 10 of the 14 patients. Notably, most patients showed complete regression of their gastric SETs after unroofing (on white light and EUS), including the glomus tumor, the leiomyoma, and 6 of the 8 cases of GIST.

CONCLUSIONS

Endoscopic unroofing was safe and had a very favorable diagnostic yield in this study. Unexpectedly, it led to complete regression in most gastric SETs. Although it is not an oncologically curative treatment, endoscopic unroofing can be a valuable option to treat local adverse events in patients unfit for surgical therapy. (Clinical trial registration number: NCT02587923.).

Partial response to imatinib treatment in a patient with unresectable gastrointestinal stromal tumor: A case report and mini literature review

The aim of the present study was to evaluate the efficacy and safety of imatinib mesylate in unresectable gastrointestinal stromal tumor (GIST) and to discuss its therapeutic regimen. A patient with unresectable GIST is described, and several key clinical studies are reviewed, including the clinical trials B2222 and S0033, which contain recently reported results of the long-term clinical outcome of imatinib in patients with unresectable or metastatic GIST. The recent results of the two studies demonstrate the long-term efficacy and safety of imatinib for unresectable or metastatic GIST. A positive response to imatinib treatment was observed in the present patient, which is consistent with the data of the B2222 and S0033 trials. However, further long-term, large-scale, multicenter and controlled trials are required to determine the relative efficacy of combining imatinib agents with surgical procedures or administering imatinib alone.

A meta-analysis of prognostic value of KIT mutation status in gastrointestinal stromal tumors

Numerous types of KIT mutations have been reported in gastrointestinal stromal tumors (GISTs); however, controversy still exists regarding their clinicopathological significance. In this study, we reviewed the publicly available literature to assess the data by a meta-analysis to characterize KIT mutations and different types of KIT mutations in prognostic prediction in patients with GISTs. Twenty-eight studies that included 4,449 patients were identified and analyzed. We found that KIT mutation status was closely correlated with size of tumors and different mitosis indexes, but not with tumor location. KIT mutation was also observed to be significantly correlated with tumor recurrence, metastasis, as well as the overall survival of patients. Interestingly, there was higher risk of progression in KIT exon 9-mutated patients than in exon 11-mutated patients. Five-year relapse-free survival (RFS) rate was significantly higher in KIT exon 11-deleted patients than in those with other types of KIT exon 11 mutations. In addition, RFS for 5 years was significantly worse in patients bearing KIT codon 557–558 deletions than in those bearing other KIT exon 11 deletions. Our results strongly support the hypothesis that KIT mutation status is another evaluable factor for prognosis prediction in GISTs.

The functional morphology and role of cardiac telocytes in myocardium regeneration

Key morphological discoveries in recent years have included the discovery of new cell populations inside the heart called cardiac telocytes. These newly described cells of the connective tissue have extremely long cytoplasmic processes through which they form functionally connected three-dimensional networks that connect cells of the immune system, nerve fibers, cardiac stem cells, and cardiac muscle cells. Based on their functions, telocytes are also referred to as "connecting cells" or "nurse cells" for cardiac progenitor stem cells. In this critical review, we provide a summary of the latest research on cardiac telocytes localized in all layers of the heart - from the historical background of their discovery, through ultrastructural, immunohistochemical, and functional characterizations, to the application of this knowledge to the fields of cardiology, stem cell research, and regenerative medicine.

Regorafenib: A Review of Its Use in Patients with Advanced Gastrointestinal Stromal Tumours

Regorafenib (Stivarga(®)) is an orally administered small molecule inhibitor of multiple protein kinases, including kinases involved in oncogenesis and tumour angiogenesis. It was initially approved for use in patients with previously treated metastatic colorectal cancer. Based on the findings of the phase III GRID clinical trial, approval for regorafenib has been expanded to include the treatment of advanced gastrointestinal stromal tumours (GISTs) following the failure of imatinib and sunitinib. In the GRID trial, regorafenib significantly improved progression-free survival and was associated with a significantly higher disease control rate than placebo. No significant between-group difference was observed in overall survival (OS) in the trial; however, the high proportion of patients who crossed over from placebo to regorafenib likely impacted the OS analysis. Regorafenib has an acceptable tolerability profile, with most adverse events being manageable with dose modification and/or supportive measures. The most commonly reported drug-related adverse events among patients receiving regorafenib in the GRID trial were hand-foot skin reaction, hypertension, diarrhoea and fatigue. In conclusion, regorafenib presents a valuable new tool in the treatment of patients with advanced GISTs following the failure of imatinib and sunitinib.

Comparison of endoscopic submucosal dissection and surgery for the treatment of gastric submucosal tumors originating from the muscularis propria layer: a single-center study (with video)

INTRODUCTION

Endoscopic submucosal dissection (ESD) has been used for the treatment of gastric submucosal tumors (SMTs). This study aims to compare clinical outcomes of ESD versus laparoscopic wedge resection (LWR) for gastric SMTs.

METHODS

This is a retrospective cohort study. Patients with SMTs who underwent ESD or LWR were enrolled in this study at a university-affiliated hospital from January 2010 to October 2015. Preoperative endoscopic ultrasound and computed tomography were performed to determine origin of layer and growth pattern. Clinical outcomes including baseline demographics, tumor size, operation time, blood loss, hospital stay, cost, pathology and postoperative complications were compared.

RESULTS

From January 2010 to October 2015, 68 patients with SMTs received ESD and 47 patients with SMTs received LWR. There was no difference in age, gender, body mass index, origin of layer and proportion with symptoms between ESD group and LWR group. However, tumor size was significantly larger in the LWR group (37.1 mm) than in the ESD group (25.8 mm, P = 0.041). For patients with tumors smaller than 20 mm, ESD was associated with shorter mean operation time (89.7 ± 23.5 vs 117.6 ± 23.7 min, P = 0.043), less blood loss (4.9 ± 1.7 vs 72.3 ± 23.3 ml, P < 0.001), shorter length of hospital stay (3.6 ± 1.9 vs 6.9 ± 3.7 days, P = 0.024) and lower cost (2471 ± 573 vs 4498 ± 1257 dollars, P = 0.031) when compared with LWR. For patients with tumors between 20 mm and 50 mm, ESD was associated with shorter mean operation time (99.3 ± 27.8 vs 125.2 ± 31.5 min, P = 0.039), less blood loss (10.1 ± 5.3 vs 87.6 ± 31.3 ml, P < 0.001), shorter length of hospital stay (4.0 ± 1.7 vs 7.3 ± 4.5 days, P = 0.027) and lower cost (2783 ± 601 vs 4798 ± 1343 dollars, P = 0.033) when compared with LWR. There were no significant differences in terms of rates of en bloc resection, complete resection and complication and histological diagnosis regardless of tumor size.

CONCLUSIONS

ESD can achieve similar oncological outcomes when compared with surgery for treatment of gastric SMT smaller than 50 mm.

Synchronous occurrence of gastrointestinal stromal tumor and acute myeloid leukemia: A case report and review of the literature

Gastrointestinal stromal tumors (GISTs) originate from the mesenchymal tissue of the gastrointestinal tract. The pathogenesis of GIST is associated with the mutational activation of the receptor tyrosine kinase cluster of differentiation (CD)117 or platelet-derived growth factor receptor-α. Overall, ~60% of GISTs occur in the stomach. Clinically, GISTs may coexist with various types of cancer, including liver cancer, pancreatic tumors and lymphoma, either synchronously or metachronously. The present study reports the case of a patient with the synchronous occurrence of a CD117-positive GIST and acute myeloid leukemia. A 69-year-old man was hospitalized for heart palpitations and dizziness, and was diagnosed with acute myeloid leukemia (AML) by bone marrow aspiration and flow cytometry analysis. An abdominal computed tomograpy and gastroscopy revealed the presence of GIST. The patient received chemotherapy in combination with imatinib (400 mg/day), and the mass was removed 2 months later. To the best of our knowledge, the present study is the first reported case of the synchronous development of a CD117-positive GIST and AML. Additional studies are required in order to understand the association between GIST and hematological malignancies.

Clinical Control Study of Endoscopic Full-thickness Resection and Laparoscopic Surgery in the Treatment of Gastric Tumors Arising from the Muscularis Propria

BACKGROUND

Gastric stromal tumors arising from the muscularis propria are located in deeper layers. Endoscopic resection may be contraindicated due to the possibility of perforation. These tumors are therefore usually removed by surgical or laparoscopic procedures. This study evaluated the curative effects, safety and feasibility of endoscopic full-thickness resection (EFR) of gastric stromal tumors originating from the muscularis propria.

METHODS

This study enrolled 92 patients with gastric stromal tumors >2.5 cm originating from the muscularis propria. Fifty patients underwent EFR, and 42 underwent laparoscopic intragastric surgery. Operation time, complete resection rate, length of hospital stay, incidence of complications, and recurrence rates were compared in these two groups.

RESULTS

EFR resulted in complete resection of all 50 gastric stromal tumors, with a mean procedure time of 85 ± 20 min, a mean hospitalization time of 7.0 ± 1.5 days and no complications. Laparoscopic intragastric surgery also resulted in a 100% complete resection rate, with a mean operation time of 88 ± 12 min and a mean hospitalization period of 7.5 ± 1.6 days. The two groups did not differ significantly in operation time, complete resection rates, hospital stay or incidence of complications (P > 0.05). No patient in either group experienced tumor recurrence.

CONCLUSIONS

EFR technique is effective and safe for the resection of gastric stromal tumors arising from the muscularis propria.

Immunohistochemical Markers of Soft Tissue Tumors: Pathologic Diagnosis, Genetic Contributions, and Therapeutic Options

After ~30 years of widespread usage, immunohistochemistry (IHC) has become a standard method of diagnosis for surgical pathology. Because of the plethora of diagnoses and often subtle nature of diagnostic criteria, IHC finds particular utility in soft tissue tumors. The use of progressively small amounts of tissue for diagnosis highlights the importance of this method. The sensitivity and crispness of IHC stains have progressively improved with the advent of new techniques. Traditionally, IHC detects cell-typic markers that characterize cell phenotypes, such as chromogranin for neuroectodermal tissue, myogenin for skeletal muscle, and cytokeratin for epithelium. However, the advent of genetic discoveries have led to IHC testing for detection of fusion gene products or overexpressed oncogenes associated with deletions and mutations. Proliferation-based markers such as Ki-67 can also be used for prognosis and grading, but more standardization is needed. Development of monoclonal antibody-based pharmaceuticals, such as imatinib or crizotinib, holds the promise of tailored anticancer therapy. IHC thus has assumed importance not only for diagnosis but also for guidance of personalized medicine.

Efficiency and safety of endoscopic resection in the management of subepithelial lesions of the stomach

BACKGROUND

Gastric subepithelial tumors represent a diagnostic and therapeutic challenge, given their histologic heterogeneity and potential malignant behavior.

OBJECTIVE

The objective of this article is to evaluate the interest, efficiency and safety of endoscopic resection for subepithelial gastric lesions of size <20 mm.

METHODS

We conducted a single-center retrospective study in a tertiary care center.

RESULTS

A total of 33 lesions (10 malignant/23 benign lesions) were studied. Mean histological size was 14.5 mm. Nine EMR, 18 ESD and six hybrid resections were performed. A total of 93.9% lesions were resected in one piece. At six months' follow-up, complete and definitive resection was obtained in 96.7% of cases. A vertical resection was insufficient in four cases. One GIST needed a complementary surgical resection, one neuroendocrine tumor was successfully treated by a new ESD session and two pancreatic rests were not additionally treated given the benign character and the absence of residual tissue in endoscopic control after six months. There was only one severe adverse event (2.9%); one pneumoperitoneum with ESD, three bleeding with one ESD and two EMR, always treated conservatively or endoscopically.

CONCLUSION

Endoscopic resection is safe and should be the procedure of choice for both diagnosis and definitive resection of subepithelial gastric lesions of size under 20 mm.

Duodenal gastrointestinal stromal tumor: From clinicopathological features to surgical outcomes

Duodenal gastrointestinal tumors represent an extremely rare subset of stromal tumors arising from interstitial cells of Cajal. In the last 30 years the comprehension of the pathophysiology and natural history of this previously misunderstood clinical entity, in association with developments in endoscopy, imaging technology, and immunohistochemistry has resulted in novel diagnostic and treatment approaches. This is a comprehensive review of the current data of the literature on the various aspects of the diagnosis and treatment of these tumors. The duodenum is the less commonly involved site for these tumors in the digestive tract. Endoscopy and computed tomography can usually establish the diagnosis, confirmed by immunohistochemical staining and occasionally molecular genetic analysis. Endoscopic ultrasound with fine needle aspiration has been recently found to be the gold diagnostic standard with high sensitivity and specificity rates, diagnosing GIST in up to 80% of patients. Due to the complex anatomy of the pancreatico-duodenal region optimal therapeutic strategy of duodenal GISTs are challenging. Nevertheless surgical resection with microscopically clear resection margins seems to be the only potentially curative treatment for non-metastatic primary GISTs of the duodenum. Imatinib mesylate plays a key role in the management of GISTs both as neoadjuvant therapy and in patients with recurrent and metastatic disease. Meanwhile, the advances in the comprehension of the pathophysiology and natural history of this previously misunderstood clinical entity as well as the treatment of these tumors may render feasible, in the near future, the advent of newer and more effective treatment options.

Impact of periodic endoscopy on incidentally diagnosed gastric gastrointestinal stromal tumors: findings in surgically resected and confirmed lesions

BACKGROUND

Although gastric gastrointestinal stromal tumors (GISTs) are usually identified by endoscopic examinations, the diagnostic value of endoscopy has not been fully evaluated. We assessed the diagnostic performance of endoscopy for gastric GISTs according to lesion characteristics. Furthermore, the benefits of periodic endoscopy prior to diagnosis of gastric GISTs were evaluated.

METHODS

We reviewed patients who underwent surgery for gastric GISTs at Severance Hospital, Seoul, Korea, between January 2008 and April 2014. In addition, we administered a questionnaire to determine the usage of periodic endoscopic inspection and the period from the penultimate endoscopy to the diagnosis.

RESULTS

Of 174 included patients, 109 (62.4 %) showed intraluminally growing GISTs and 65 (37.4 %) showed extraluminally growing GISTs. The proportions of lesions that were initially diagnosed via endoscopy were 99.1 % for intraluminally growing GISTs and 49.2 % for extraluminally growing GISTs (P < 0.001). In patients with intraluminally growing GISTs, patients who had undergone endoscopy within 3 years prior to the diagnosis showed smaller tumor sizes (P = 0.015) and fewer tumors with ulceration (7.1 vs. 28.4 %, P = 0.021). The proportion of GISTs with a high mitotic index did not differ according to the usage of periodic endoscopy (P = 0.639). In contrast, lesion characteristics of the extraluminally growing GISTs did not differ according to whether an endoscopy was performed within 3 years prior to the diagnosis.

CONCLUSIONS

Endoscopic examinations had a limited role in the diagnosis of extraluminally growing GISTs. However, periodic endoscopy was associated with relatively earlier detection of growth in intraluminal gastric GISTs.

Cancer stem cells in basic science and in translational oncology: can we translate into clinical application?

Since their description and identification in leukemias and solid tumors, cancer stem cells (CSC) have been the subject of intensive research in translational oncology. Indeed, recent advances have led to the identification of CSC markers, CSC targets, and the preclinical and clinical evaluation of the CSC-eradicating (curative) potential of various drugs. However, although diverse CSC markers and targets have been identified, several questions remain, such as the origin and evolution of CSC, mechanisms underlying resistance of CSC against various targeted drugs, and the biochemical basis and function of stroma cell-CSC interactions in the so-called ‘stem cell niche.’ Additional aspects that have to be taken into account when considering CSC elimination as primary treatment-goal are the genomic plasticity and extensive subclone formation of CSC. Notably, various cell fractions with different combinations of molecular aberrations and varying proliferative potential may display CSC function in a given neoplasm, and the related molecular complexity of the genome in CSC subsets is considered to contribute essentially to disease evolution and acquired drug resistance. In the current article, we discuss new developments in the field of CSC research and whether these new concepts can be exploited in clinical practice in the future.