Prognostic Indicators for Gastrointestinal Stromal Tumors: A Review

A Rare Case of Colonic Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumors (GISTs) are a type of mesenchymal tumor of the gastrointestinal tract that originate anywhere in the gastrointestinal tract, with the colon and appendix being the least recorded sites of occurrence. The following case report is that of a colonic GIST in a 53-year-old male and its histologic type. Included are notes on the recent additions and updates in the risk stratification of GISTs occurring in unusual sites with the relevant immunohistochemistry.

Genomic profiling in GIST: Implications in clinical outcome and future challenges

Gastrointestinal Stromal Tumors (GIST) are the most frequent mesenchymal neoplasia of the digestive tract. Genomic alterations in KIT, PDFGRA, SDH, and BRAF genes are essential in GIST oncogenesis. Therefore, the mutations in these genes have demonstrated clinical implications. Tumors with deletions in KIT-exon 11 or duplications in exon 9 are associated with a worse prognosis. In contrast, KIT-exon 11 substitutions and duplications are associated with a better clinical outcome. Moreover, mutations in Kit exon 9 and 11 are actionable, due to their response to imatinib, while mutations in PDGFRA respond to sunitinib and/or avapritinib. Although, molecular testing on tissue samples is effective; it is invasive, requires adequate amounts of tissue, and a long experimental process is needed for results. In contrast, liquid biopsy has been proposed as a simple and non-invasive method to test biomarkers in cancer. The most common molecule analyzed by liquid biopsy is circulating tumor DNA (ctDNA). GISTs ctDNA testing has been demonstrated to be effective in identifying known and novel KIT mutations that were not detected using traditional tissue DNA testing and have been useful in determining progression risk and response to TKI therapy. This allows the clinician to have an accurate picture of the genetic changes of the tumor over time. In this work, we aimed to discuss the implications of mutational testing in clinical outcomes, the methods to test ctDNA and the future challenges in the establishment of alternatives of personalized medicine.

Exploring Perforated Jejunal GIST: A Rare Case Report and Review of Molecular and Clinical Literature

This case report details a rare instance of a perforated jejunal gastrointestinal stromal tumor (GIST) in a 76-year-old female patient. The patient presented with acute abdominal pain and distension without any changes in bowel habits or episodes of nausea and vomiting. Initial diagnostics, including abdominal plain radiography and ultrasonography, were inconclusive; however, a computed tomography (CT) scan revealed pneumoperitoneum and an irregular fluid collection suggestive of small intestine perforations. Surgical intervention uncovered a 35 mm jejunal GIST with a 10 mm perforation. Histopathological examination confirmed a mixed cell type GIST with high malignancy potential, further substantiated by immunohistochemistry markers CD117, DOG1, and vimentin. Molecular analysis illuminated the role of key oncogenes, primarily KIT and PDGFRA mutations, emphasizing the importance of molecular diagnostics in GIST management. Despite the severity of the presentation, the patient's postoperative recovery was favorable, highlighting the effectiveness of prompt surgical and multidisciplinary approaches in managing complex GIST cases.

A mutation-based radiomics signature predicts response to imatinib in Gastrointestinal Stromal Tumors (GIST)

Objectives

To develop a mutation-based radiomics signature to predict response to imatinib in Gastrointestinal Stromal Tumors (GISTs).

Methods

Eighty-two patients with GIST were enrolled in this retrospective study, including 52 patients from one center that were used to develop the model, and 30 patients from a second center to validate it. Reference standard was the mutational status of tyrosine-protein kinase (KIT) and platelet-derived growth factor α (PDGFRA). Patients were dichotomized in imatinib sensitive (group 0 - mutation in KIT or PDGFRA, different from exon 18-D842V), and imatinib non-responsive (group 1 - PDGFRA exon 18-D842V mutation or absence of mutation in KIT/PDGFRA). Initially, 107 texture features were extracted from the tumor masks of baseline computed tomography scans. Different machine learning methods were then implemented to select the best combination of features for the development of the radiomics signature.

Results

The best performance was obtained with the 5 features selected by the ANOVA model and the Bayes classifier, using a threshold of 0.36. With this setting the radiomics signature had an accuracy and precision for sensitive patients of 82 % (95 % CI:60-95) and 90 % (95 % CI:73-97), respectively. Conversely, a precision of 80 % (95 % CI:34-97) was obtained in non-responsive patients using a threshold of 0.9. Indeed, with the latter setting 4 patients out of 5 were correctly predicted as non-responders.

Conclusions

The results are a first step towards using radiomics to improve the management of patients with GIST, especially when tumor tissue is unavailable for molecular analysis or when molecular profiling is inconclusive.

Is single incision laparoscopic surgery (SILS) for gastric gastrointestinal stromal tumor (GIST) dependent on the location of the tumor?

BACKGROUND

We compared the surgical outcomes of single-incision laparoscopic surgery (SILS) and conventional laparoscopic surgery (CLS) for gastric gastrointestinal stromal tumor (GIST).

METHODS

We performed single-incision gastric wedge resection on prospectively-enrolled 15 consecutive patients with gastric GIST between November 2020 and April 2022 in a single tertiary center. The early perioperative outcomes of these patients were compared to those of patients who underwent CLS. The indications did not differ from those for conventional laparoscopic procedures for gastric GIST.

RESULTS

In total, 30 patients were assigned to the SILS (n = 15) and CLS (n = 15) groups. There were no significant differences in the estimated blood loss and intraoperative blood transfusion between the SILS and CLS groups. There were no intraoperative complications or conversions to multiple-port or open surgery in the SILS group. Proximally located tumors were more commonly treated with CLS than with SILS (P = 0.045). GISTs located in the greater curvature were more commonly treated with SILS than with CLS, although the difference was not statistically significant (P = 0.08). The mean incision length in the SILS group was 4.1 cm shorter than that in the CLS group (3.2 ± 0.7 and 7.3 ± 5.2 cm, respectively, P = 0.01). The postoperative analgesic dose was significantly lower in the SILS than in the CLS group (0.4 ± 1.4 and 2.1 ± 2.3, respectively P = 0.01). Also, the duration of postoperative use of analgesic was shorter in SILS than in CLS (0.4 ± 0.7 and 2.0 ± 1.8, respectively, P = 0.01). There were no significant differences in the early postoperative complications between the groups.

CONCLUSIONS

SILS is as safe, feasible, and effective for the treatment of gastric GIST as CLS with comparable postoperative complications, pain, and cosmesis. Moreover, SILS can be considered without being affected by the type or location of the tumor.

Gastrointestinal Stromal Tumors: Our Ten-Year Experience of a Single-Center Tertiary Hospital

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal neoplasms of the gastrointestinal tract. They have variable clinical presentation, prognosis, and molecular characteristics. Here, we present the results of our retrospective study including patients operated on for GIST during the last decade.

METHODS

All the patients who underwent GIST resection during the decade 2008-2018 were included in the study. The diagnosis was based on the pathology report. All the data were collected and analyzed statistically using the Statistical Package for Social Science v25.0. Finally, after having applied the proper search terms, a comprehensive review of articles published in the Medline database was held.

RESULTS

Thirty-two patients (sixteen women) were included in the study with a mean age of 69.6 years old (SD = 13.9). Twenty-one patients had a GIST in the stomach, eight in the small intestine, and three had an extra GIST. Of the 29 patients contacted, 21 were alive with a mean survival time of 74.3 months (SD = 49.6 months, min: 3.0 months, max: 161.0 months), whereas eight patients passed away. Finally, 13 patients were treated with tyrosine kinase inhibitors (TKIs) of whom only one died, while 9 patients passed away from those treated with surgery alone (p = 0.031).

CONCLUSIONS

Our results were in concordance with the existing data in the literature. GISTs require patient-based therapeutical management depending on the histology of the tumors. Gastric tumors present a better prognosis than those localized in the intestine, while the use of TKIs has led to an improvement in patient survival rate.

A multiplatform metabolomics approach for comprehensive analysis of GIST xenografts with various KIT mutations

Metabolites in biological matrices belong to diverse chemical groups, ranging from non-polar long-chain fatty acids to small polar molecules. The goal of untargeted metabolomic analysis is to measure the highest number of metabolites in the sample. Nevertheless, from an analytical point of view, no single technique can measure such a broad spectrum of analytes. Therefore, we selected a method based on GC-MS and LC-MS with two types of stationary phases for the untargeted profiling of gastrointestinal stromal tumours. The procedure was applied to GIST xenograft samples (n = 71) representing four different mutation models, half of which were treated with imatinib. We aimed to verify the method coverage and advantages of applying each technique. RP-LC-MS measured most metabolites due to a significant fraction of lipid components of the tumour tissue. What is unique and worth noting is that all applied techniques were able to distinguish between different mutation models. However, for detecting imatinib-induced alterations in the GIST metabolome, RP-LC-MS and GC-MS proved to be more relevant than HILIC-LC-MS, resulting in a higher number of significantly changed metabolites in four treated models. Undoubtedly, the inclusion of all mentioned techniques makes the method more comprehensive. Nonetheless, for green chemistry and time and labour saving, we assume that RP-LC-MS and GC-MS analyses are sufficient to cover the global GIST metabolome.

A Review of 10-Year Survivability of Immunotherapy in the Management of Colon Cancer

Colon cancer is one of the most common cancers in the United States of America. In addition to conventional treatment approaches such as surgery, chemotherapy, and radiation for colorectal cancer, immunotherapy has gained recognition over the past few years. However, its effectiveness in colorectal cancer treatment is controversial. Our study investigates the survival and progression-free rates of immunotherapy for different types of colorectal cancer over the last 10 years. We conducted literature reviews from various clinical trials and research studies to evaluate immunotherapy's role in colorectal cancer treatment. We also investigated how it affects clinical outcomes. We discovered a range of effective immunotherapy approaches targeting various growth factors and signaling pathways. These modalities include monoclonal antibodies aimed at growth factors such as epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), human epidermal growth factor receptor 2 (HER2), and downstream signaling pathways such as mitogen-activated protein kinase (MAPK), kirsten rat sarcoma viral oncogene (KRAS), B-raf proto-oncogene, serine/threonine kinase (BRAF), and phosphatase and tensin homolog (PTEN). Additionally, we identified immune checkpoint inhibitors, such as cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitors and programmed cell death ligand 1 (PD-L1) inhibitors, as well as target therapy and adoptive cell therapy as promising immunotherapeutic options. Nevertheless, the application of immunotherapy remains highly limited due to various factors influencing survival and progression-free rates, including tumor microenvironment, microsatellite instability, immune checkpoint expression, and gut microbiome. Additionally, its effectiveness is restricted to a small subgroup of patients, accompanied by side effects and the development of drug resistance mechanisms. To unlock its full potential, further clinical trials and research on molecular pathways in colorectal cancer are imperative. This will ultimately enhance drug discovery success and lead to more effective clinical management approaches.

Gastrointestinal Stromal Tumor Presenting as Food Impaction and Pseudo-Achalasia

Gastrointestinal stromal tumors (GISTs) are one of the most common mesenchymal tumors of the gastrointestinal tract. Studies report the incidence of GIST to be 14.5 per million, with 18% being diagnosed incidentally. The most common location is the stomach while the esophagus is the rarest, representing only 0.7% of cases. The clinical manifestations of GISTs vary. Most patients present with bleeding and gastric discomfort. Some may present with life-threatening hematemesis or melena. We present a unique case of a GIST presenting as pseudo-achalasia and food impaction.

Giant gastric GIST with fast-growing mass after intra-tumoral bleeding

Only a few instances of giant gastrointestinal stromal tumors and even fewer cases of such tumors with intra-tumoral bleeding have ever been reported. This report represents a case with both giant size and intra-tumoral spontaneous hemorrhage. Here a 42-year-old male patient presented with abdominal pain and abdominal distention of 5-month duration. The distention had fast growth over 1 month before the hospital presentation. Physical examination showed a conjunctival pallor and an ill-defined abdominal mass. A contrast-enhanced computed tomography (CT) scan showed a huge intra-abdominal mass with variable enhancements. Surgical exploration was done and a huge mass measuring 10.5 kg with dimensions of 32 × 30 × 15 cm was excised en-bloc with distal gastrectomy.

Efficacy and safety of ripretinib in Chinese patients with advanced gastrointestinal stromal tumors: a real-world, multicenter, observational study

Introduction

Mutations in KIT proto-oncogene, receptor tyrosine kinase (KIT) and platelet-derived growth factor receptor-α (PDGFRA) render the available tyrosine kinase inhibitors (TKI) ineffective in treating advanced gastrointestinal stromal tumors (GIST). Ripretinib, a broad-spectrum switch-control kinase inhibitor, has shown increased efficacy and manageable safety, but real-world evidence remains scarce. This study evaluates the efficacy and safety of ripretinib among Chinese patients in a real-world setting.

Methods

Advanced GIST patients (N=23) receiving ripretinib following progression on previous lines of TKI treatment were enrolled to determine the efficacy [progression-free survival (PFS) and overall survival (OS)]. Safety was assessed by the incidence and severity of adverse events (AEs). All statistical analyses were performed using SPSS version 20.0 and a p-value of <0.05 was considered significant.

Results

The median PFS (mPFS) of efficacy analysis set (EAS) (N=21) was 7.1 months. mPFS of patients receiving ripretinib following ≤2 lines of previous TKI treatment and ≥3 prior lines of therapy were 7.1 and 9.2 months, respectively. The median OS (mOS) was 12.0 months and shorter interval between the end of the latest TKI and ripretinib therapy was correlated with longer median PFS and OS (p=0.054 and p=0.046), respectively. Alopecia and asthenia were the most common AEs observed.

Conclusion

Compared to previous lines of TKI in advanced GIST patients, ripretinib showed superior efficacy with clinically manageable AEs. Real-world results are comparable to that of phase III INVICTUS study and its Chinese bridging study. Hence, ripretinib can be used for the clinical management of advanced GIST patients.

The Epithelial to Mesenchymal Transition in Colorectal Cancer Progression: The Emerging Role of Succinate Dehydrogenase Alterations and Succinate Accumulation

Colorectal cancer (CRC) stands as the third most significant contributor to cancer-related mortality worldwide. A major underlying reason is that the detection of CRC usually occurs at an advanced metastatic stage, rendering therapies ineffective. In the progression from the in situ neoplasia stage to the advanced metastatic stage, a critical molecular mechanism involved is the epithelial-to-mesenchymal transition (EMT). This intricate transformation consists of a series of molecular changes, ultimately leading the epithelial cell to relinquish its features and acquire mesenchymal and stem-like cell characteristics. The EMT regulation involves several factors, such as transcription factors, cytokines, micro RNAs and long noncoding RNAs. Nevertheless, recent studies have illuminated an emerging link between metabolic alterations and EMT in various types of cancers, including colorectal cancers. In this review, we delved into the pivotal role played by EMT during CRC progression, with a focus on highlighting the relationship between the alterations of the tricarboxylic acid cycle, specifically those involving the succinate dehydrogenase enzyme, and the activation of the EMT program. In fact, emerging evidence supports the idea that elucidating the metabolic modifications that can either induce or inhibit tumor progression could be of immense significance for shaping new therapeutic approaches and preventative measures. We conclude that an extensive effort must be directed towards research for the standardization of drugs that specifically target proteins such as SDH and SUCNR1, but also TRAP1, PDH, ERK1/2, STAT3 and the HIF1-α catabolism.

Prognostic analysis of 2-5 cm diameter gastric stromal tumors with exogenous or endogenous growth

BACKGROUND

There has been limited research on the prognosis differences in patients with gastric stromal tumor invasion of the plasma membrane surface. This study intended to investigate whether there is a difference in prognosis in patients with endogenous or exogenous 2-5 cm diameter GISTs.

METHODS

We retrospectively analyzed the clinicopathological and follow-up data of gastric stromal tumor patients, all of whom underwent surgical resection for primary GIST at Nanjing Drum Tower Hospital from December 2010 to February 2022. We classified patients based on tumor growth patterns and then investigated the association between tumor growth patterns and clinical outcomes. Progression-free survival (PFS) and overall survival (OS) were calculated by the Kaplan‒Meier method.

RESULTS

A total of 496 gastric stromal tumor patients were enrolled in this study, among which 276 patients had tumors of 2-5 cm in diameter. Of these 276 patients, 193 had exogenous tumors, and 83 had endogenous tumors. Tumor growth patterns were significantly related to age, rupture status, resection style, tumor site, tumor size, and intraoperative bleeding. According to Kaplan‒Meier curve analysis, the tumor growth pattern among patients with 2-5 cm diameter tumors was significantly correlated with worse progression-free survival (PFS). Ultimately, multivariate analyses identified the Ki-67 index (P = 0.008), surgical history (P = 0.031), and resection style (P = 0.045) as independent prognostic markers for PFS.

CONCLUSIONS

Although gastric stromal tumors with a diameter of 2-5 cm are classified as low risk, the prognosis is lower for exogenous tumors than for endogenous tumors, and exogenous gastric stromal tumors have a risk of recurrence. Consequently, clinicians should be vigilant regarding the prognosis of patients with this type of tumor.

Clinicopathological, immunohistochemical, molecular-genetic and risk profiles of gastrointestinal stromal tumors in a cohort of Sudanese patients

Background

Determining the risk of malignant behaviour and mutational status of gastrointestinal stromal tumours (GISTs) guide the management decision and allow optimal individualized patient treatment.

Objectives

To determine clinicopathological, immunohistochemical (IHC), risk and KIT mutational findings of GISTs in Sudanese patients.

Methods

Histological slides were reviewed, IHC for DOG-1 and CD117 performed and hotspot KIT mutations examined. The risk group was assigned using combined risk criteria.

Results

21 of the 36 patients (58.3%) were males (mean age, 54.83 ±12.57; range, 26-71). Abdominal pain and mass were the most frequent symptoms. Mean tumor size (±SD) was 11.6(±5.82) cm. Either CD117, DOG1 or both were positive in all cases. Using risk criteria, 33.3% (n=12) were clinically malignant at presentation, 13.9% (n=5) high risk, 16.7% (n=6) intermediate, 27.8% (n=10) low risk and 2.8% (n=1) very low risk. Sixteen of 23 (70%) tested cases had KIT (14 exon 11 and two exon 9) mutations. Six tumors were wild type. Exon 11 deletions (p.I563-L576 del and p.V559-N566delinsD) significantly correlate with disease recurrence (p-value: 0.028).

Conclusions

Sudanese patients with GIST tend to present late. Nearly half of them correspond to the malignant/high-risk category. The frequency of KIT mutations (79.31%) is in line with the literature.

Molecular Mechanisms of Gastrointestinal Stromal Tumors and Their Impact on Systemic Therapy Decision

Gastrointestinal stromal tumors (GISTs) are soft tissue sarcomas that mostly derive from Cajal cell precursors. They are by far the most common soft tissue sarcomas. Clinically, they present as gastrointestinal malignancies, most often with bleeding, pain, or intestinal obstruction. They are identified using characteristic immunohistochemical staining for CD117 and DOG1. Improved understanding of the molecular biology of these tumors and identification of oncogenic drivers have altered the systemic treatment of primarily disseminated disease, which is becoming increasingly complex. Gain-of-function mutations in KIT or PDGFRA genes represent the driving mutations in more than 90% of all GISTs. These patients exhibit good responses to targeted therapy with tyrosine kinase inhibitors (TKIs). Gastrointestinal stromal tumors lacking the KIT/PDGFRA mutations, however, represent distinct clinico-pathological entities with diverse molecular mechanisms of oncogenesis. In these patients, therapy with TKIs is hardly ever as effective as for KIT/PDGFRA-mutated GISTs. This review provides an outline of current diagnostics aimed at identifying clinically relevant driver alterations and a comprehensive summary of current treatments with targeted therapies for patients with GISTs in both adjuvant and metastatic settings. The role of molecular testing and the selection of the optimal targeted therapy according to the identified oncogenic driver are reviewed and some future directions are proposed.

What Is the Significance of Lysosomal-Mediated Resistance to Imatinib?

The lysosomal sequestration of hydrophobic weak-base anticancer drugs is one proposed mechanism for the reduced availability of these drugs at target sites, resulting in a marked decrease in cytotoxicity and consequent resistance. While this subject is receiving increasing emphasis, it is so far only in laboratory experiments. Imatinib is a targeted anticancer drug used to treat chronic myeloid leukaemia (CML), gastrointestinal stromal tumours (GISTs), and a number of other malignancies. Its physicochemical properties make it a typical hydrophobic weak-base drug that accumulates in the lysosomes of tumour cells. Further laboratory studies suggest that this might significantly reduce its antitumor efficacy. However, a detailed analysis of published laboratory studies shows that lysosomal accumulation cannot be considered a clearly proven mechanism of resistance to imatinib. Second, more than 20 years of clinical experience with imatinib has revealed a number of resistance mechanisms, none of which is related to its accumulation in lysosomes. This review focuses on the analysis of salient evidence and raises a fundamental question about the significance of lysosomal sequestration of weak-base drugs in general as a possible resistance mechanism both in clinical and laboratory settings.

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.

Metabolomic and transcriptomic response to imatinib treatment of gastrointestinal stromal tumour in xenograft-bearing mice

BACKGROUND

Although imatinib is a well-established first-line drug for treating a vast majority of gastrointestinal stromal tumours (GIST), GISTs acquire secondary resistance during therapy. Multi-omics approaches provide an integrated perspective to empower the development of personalised therapies through a better understanding of functional biology underlying the disease and molecular-driven selection of the best-targeted individualised therapy. In this study, we applied integrative metabolomic and transcriptomic analyses to elucidate tumour biochemical processes affected by imatinib treatment.

MATERIALS AND METHODS

A GIST xenograft mouse model was used in the study, including 10 mice treated with imatinib and 10 non-treated controls. Metabolites in tumour extracts were analysed using gas chromatography coupled with mass spectrometry (GC-MS). RNA sequencing was also performed on the samples subset (n=6).

RESULTS

Metabolomic analysis revealed 21 differentiating metabolites, whereas next-generation RNA sequencing data analysis resulted in 531 differentially expressed genes. Imatinib significantly changed the profile of metabolites associated mainly with purine and pyrimidine metabolism, butanoate metabolism, as well as alanine, aspartate, and glutamate metabolism. The related changes in transcriptomic profiles included genes involved in kinase activity and immune responses, as well as supported its impact on the purine biosynthesis pathway.

CONCLUSIONS

Our multi-omics study confirmed previously known pathways involved in imatinib anticancer activity as well as correlated imatinib-relevant downregulation of expression of purine biosynthesis pathway genes with the reduction of respectful metabolites. Furthermore, considering the importance of the purine biosynthesis pathway for cancer proliferation, we identified a potentially novel mechanism for the anti-tumour activity of imatinib. Based on the results, we hypothesise metabolic modulations aiming at the reduction in purine and pyrimidine pool may ensure higher imatinib efficacy or re-sensitise imatinib-resistant tumours.

Management of gastrointestinal subepithelial lesions: an answer to the conflicting opinions

Subepithelial lesions, formerly known as subepithelial tumors, are incidentally discovered protrusions throughout the gastrointestinal tract with normal overlying mucosa. Studies related to the diagnosis and therapy methods are limited due to the low incidence and malignant potential of these lesions. They commonly originating from the second, third, and fourth layers (muscularis mucosa, submucosa, and muscularis propria) of the gastrointestinal wall. They are reported to be more prevalent in the stomach and esophagus than small intestine and colon. Subepithelial lesions in the stomach and duodenum are more prone to malignancy than the lesions in the esophagus. Despite different strategies in the management of subepithelial lesions based on their size and location, there is still not a unique consensus on the issue. In this review, we have attempted to introduce the most practical approach to managing gastrointestinal subepithelial lesions based on current guidelines.

A Rare Case of Breast Metastatic Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumor (GIST) is one of the most common spindle cell neoplasms of the alimentary system, and can arise anywhere along the gastrointestinal tract (GI). Its incidence rate is up to 22 cases per million, with a minor geographic variation. GIST is thought to originate from interstitial cell of Cajal, and its pathogenesis is related to molecular defects, such as KIT receptor tyrosine kinase or platelet-derived growth receptor alpha gene activation. While the majority of GISTs are known to show a benign disease course, metastases of high-grade forms to different organ systems have been seldom reported. We present a case with an unprecedented metastasis of GIST to the breast. The patient is a 62-year-old female with a history of the primary resection of GIST from the small intestine. Her disease course was initially complicated by multiple metastases, solely localized to the liver for which she had a living-donor liver transplant. The tumor harbored both KIT exon 11 and exon 17 mutation. Fourteen months post-transplant, the patient was found to have metastatic GIST on her breast biopsy. GIST metastasis to the breast is extremely rare. A consideration of this spindle cell neoplasm as a differential is recommended when clinical suspicion arises. The pathophysiology, current diagnostic tool, grading system, and treatment of this tumor are discussed.

Construction and validation of a prognostic model for gastrointestinal stromal tumors based on copy number alterations and clinicopathological characteristics

Background

The increasing incidence of gastrointestinal stromal tumors (GISTs) has led to the discovery of more novel prognostic markers. We aim to establish an unsupervised prognostic model for the early prediction of the prognosis of future patients with GISTs and to guide clinical treatment.

Methods

We downloaded the GISTs dataset through the cBioPortal website. We extracted clinical information and pathological information, including the microsatellite instability (MSI) score, fraction genome altered (FGA) score, tumor mutational burden (TMB), and copy number alteration burden (CNAB), of patients with GISTs. For survival analysis, we used univariate Cox regression to analyze the contribution of each factor to prognosis and calculated a hazard ratio (HR) and 95% confidence interval (95% CI). For clustering groupings, we used the t-distributed stochastic neighbor embedding (t-SNE) method for data dimensionality reduction. Subsequently, the k-means method was used for clustering analysis.

Results

A total of 395 individuals were included in the study. After dimensionality reduction with t-SNE, all patients were divided into two subgroups. Cluster 1 had worse OS than cluster 2 (HR=3.45, 95% CI, 2.22-5.56, P<0.001). The median MSI score of cluster 1 was 1.09, and the median MSI score of cluster 2 was 0.24, which were significantly different (P<0.001). The FGA score of cluster 1 was 0.28, which was higher than that of cluster 2 (P<0.001). In addition, both the TMB and CNAB of cluster 1 were higher than those of cluster 2, and the P values were less than 0.001.

Conclusion

Based on the CNA of GISTs, patients can be divided into high-risk and low-risk groups. The high-risk group had a higher MSI score, FGA score, TMB and CNAB than the low-risk group. In addition, we established a prognostic nomogram based on the CNA and clinicopathological characteristics of patients with GISTs.

Ki-67 index assessment on FNA specimens of gastrointestinal stromal tumor: Correlation with mitotic rate and potential predictive value for risk stratification

BACKGROUND

Risk assessment of gastrointestinal stromal tumor (GIST) is challenging on cytology specimens. This study aims to determine whether Ki-67 index evaluated on fine-needle aspiration (FNA) specimens can correlate with the mitotic rate of GIST in surgical specimens and provide further risk assessment.

METHODS

Cases with cell blocks containing adequate tumor cells and surgical resections were included. Ki-67 immunostain was retrospectively performed on cell block sections, and Ki-67 index was calculated on the "hot spot" areas.

RESULTS

This study included 50 GIST cases from stomach (n = 45; 90%), duodenum (n = 4; 8%), and distal esophagus (n = 1; 2%). The tumor size ranged from 1.5 cm to 21 cm (mean, 5.4 cm). Based on the mitotic count, 37 GISTs (74%) had low mitotic rate (LMR) and 13 GISTs (26%) had high mitotic rate (HMR). The spindle cell, epithelioid, and mixed types accounted for 60%, 14%, and 26% of GIST, respectively. Ki-67 index counted on cell block sections correlated well with mitotic count evaluated in surgical specimens (r = 0.8031). Mean Ki-67 index was higher in HMR than LMR groups (3.5% vs. 1%, p < .001). The receiver operating characteristic curve using Ki-67 index to predict mitotic rate was further analyzed, and area under the curve was 0.839. Using a cutoff of 2.5% yielded a sensitivity of 70% at 92% specificity.

CONCLUSIONS

This study demonstrates good correlations between Ki-67 index and mitotic count or risk stratification, suggesting that Ki-67 index evaluated on cytology specimens may offer a promising approach to preoperatively predict the mitotic rate and risk of GIST.

Prognostic and clinicopathological significance of the Prognostic Nutritional Index in patients with gastrointestinal stromal tumours undergoing surgery: a meta-analysis

OBJECTIVES

Previous studies have investigated the prognostic value of the Prognostic Nutritional Index (PNI) in patients with gastrointestinal stromal tumours (GISTs). However, the results have been inconsistent. We performed a meta-analysis to quantitatively determine the prognostic and clinicopathological significance of PNI in GISTs.

DESIGN

This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Pooled HRs and 95% CIs were calculated to estimate the prognostic value of PNI in patients with GISTs. Combined ORs and corresponding 95% CIs were used to evaluate the association between the PNI and clinicopathological characteristics.

DATA SOURCES

The electronic databases PubMed, Web of Science, Embase and Cochrane Library were thoroughly searched from inception to December 2021.

ELIGIBILITY CRITERIA

A random-effects model or fixed-effects model was selected based on the level of heterogeneity among the included studies.

RESULTS

Eight studies comprising 2307 patients were included in this meta-analysis. A low PNI was significantly associated with worse recurrence-free survival (RFS) (HR 2.02, 95% CI 1.66 to 2.47, p<0.001) and overall survival (OS) (HR 4.35, 95% CI 1.25 to 16.83, p=0.033) in patients with GISTs. In addition, a low PNI was significantly associated with tumour size ≥5 cm (OR 1.65, 95% CI 1.21 to 2.24, p=0.002) and primary tumour site in small intestine/colorectum/extra-GISTs (OR 2.03, 95% CI 1.26 to 3.26, p=0.004).

CONCLUSIONS

Patients with GISTs and a lower PNI had inferior RFS and OS. Patients with GISTs and a low PNI may have a higher risk of tumour recurrence.

Prognostic Nomogram for Gastrointestinal Stromal Tumors after Surgery Based on the SEER Database

We aimed to determine prognostic factors and develop an effective and practical nomogram for predicting cancer-specific survival in gastrointestinal stromal tumor (GIST) patients. Postoperative data were obtained from the SEER database (2000-2018). Patients were divided into training and validation cohorts at random (7 : 3). Prognostic factors were screened, and a prognostic nomogram was established using log-rank testing and Cox regression. We used DCA, ROC curves, C-index, and calibration curves to evaluate our model's predictive performance. The clinical value of the nomogram and the modified National Institute of Health (M-NIH) classification were compared using the NRI and IDI. The Kaplan-Meier method was applied to examine survival by risk group, and log-rank tests were applied to compare variations in survival curves. Independent prognostic risk factors associated with cancer-specific survival on multivariate Cox proportional hazards regression analysis were age, race, and tumor location, size, grade, and stage. Clinically relevant variables need to be considered in addition to statistically significant variables when developing prognostic models to aid clinical decision-making. We included two additional variables (mitotic rate and chemotherapy) when constructing the prognostic model. The C-index was 0.766 (95% confidence interval (CI): 0.737-0.794) in the training cohort and 0.795 (95% CI: 0.754-0.836) in the internal validation group suggesting robustness. The areas under the ROC curve for three-year and five-year survival were >0.700, indicating satisfactory discrimination. The calibration curves showed good agreement between the predictions of the nomogram and the actual results. The NRI (0.346 for 3-year and 0.265 for 5-year cancer-specific survival for patients with GIST (GSS) prediction; validation cohort: 0.356 for 3-year and 0.246 for 5-year GSS prediction) and IDI values (0.047 for 3-year and 0.060 for 5-year GSS prediction; validation cohort: 0.071 for 3-year and 0.084 for 5-year GSS prediction) suggested that the established nomogram performed significantly better than the M-NIH classification. The DCA indicated that the nomogram was clinically useful and had a high discriminative ability in identifying patients who were at high risk of poor outcomes. According to nomogram findings, patients were divided into three groups (high, moderate, and low risk), with significantly different prognoses in both cohorts. Our nomogram satisfactorily predicted survival in postsurgical GIST patients, which may assist clinicians to evaluate the postoperative status and guide subsequent treatments.

Ferroptosis Induction and YAP Inhibition as New Therapeutic Targets in Gastrointestinal Stromal Tumors (GISTs)

GISTs are sarcomas of the gastrointestinal tract often associated with gain-of-function mutations in KIT or PDGFRA receptor genes. While most GISTs initially respond to tyrosine kinase inhibitors, relapses due to acquired resistance frequently occur. The induction of ferroptosis, an iron-dependent form of non-apoptotic cell death, emerged as a novel therapeutic approach in cancers and remains poorly characterized in GISTs. We studied hallmarks of ferroptosis, i.e., lipid peroxidation, iron and glutathione content, and GPX4 protein expression in imatinib-sensitive (GIST882) and -resistant (GIST48) GIST cell lines. GIST cells were highly sensitive to the induction of ferroptosis by RSL3, which was reversed by liproxstatin and deferoxamine. Lipid peroxidation and ferroptosis were mediated by VP and CA3 in GIST cells through a significant decrease in antioxidant defenses. Moreover, VP, but surprisingly not CA3, inhibited a series of target genes downstream of YAP in GIST cells. The ferroptosis marker TFRC was also investigated by immunohistochemistry in GIST tissue arrays. TFRC expression was observed in all samples. High TFRC expression was positively correlated with high-risk GISTs, elevated mitotic count, and YAP nuclear localization, reflecting YAP activation. This study highlights ferroptosis as a novel cell death mechanism in GISTs, and a potential therapeutic target to overcome resistance to tyrosine kinase inhibitors.

Safety and efficacy of surgical and endoscopic resection in the treatment of duodenal subepithelial lesions

BACKGROUND

Duodenal subepithelial lesions (D-SELs) are rare and their resection is challenging. Unfortunately, data on surgical and endoscopic resection of D-SELs are scarce. This study aimed to assess the safety and efficacy of surgical resection and endoscopic resection (ER) for D-SELs.

METHODS

We retrospectively analyzed clinical data of patients with non-ampullary D-SELs who underwent ER or surgery and compared the outcomes between ER and surgery with no/low-risk SELs over 15 mm from March 2010 to August 2020. Clinicopathologic findings, procedure-related parameters, and follow-up data were analyzed.

RESULTS

A total of 107 patients (108 lesions) were enrolled; 52 patients (53 lesions) received ER and 55 patients (55 lesions) received surgery. In ER group, en bloc resection rate and R0 resection rate were 94 and 89%, respectively. Major adverse events rate was 6%. One (2%) patient experienced local recurrence. In surgery group, R0 resection was achieved in all cases. Major adverse events rate was 20%. Recurrence rate and distant metastases rate were 4 and 8%, respectively. One (2%) patient died from septicemia during follow-up. Thirty-three patients in each group were enrolled in the comparison. There were no significant differences in age, sex, lesion size and location (P > 0.05). More histologically GISTs and muscularis propria-originated lesions were treated by surgery (P < 0.05). ER was significantly associated with a shorter operation time, shorter hospital stay, lower cost, less estimated blood loss, and lower major adverse events rate compared to the surgery group (P < 0.05). However, R0 resection rate, mortality, recurrence rate, and metastases rate were not significant different (P > 0.05).

CONCLUSIONS

ER is an effective and safe treatment modality for selected patients with non-ampullary D-SELs by expert endoscopists. Surgery is a radical method for D-SELs that should be reserved for D-SELs not amenable to ER.

Ki67 for evaluating the prognosis of gastrointestinal stromal tumors: A systematic review and meta‑analysis

Overexpression of Ki67 is observed in tumor cells, and it has been suggested to be a marker for cancer prognosis. However, the relationship between Ki67 expression and the risk of recurrence of gastrointestinal stromal tumors (GISTs) remains poorly defined. In the present study, a meta-analysis was used to examine the associations between Ki67 levels and GIST recurrence. Studies reporting GIST and Ki67 were found by searching Cochrane Library, PubMed and Embase until October 14, 2021. The Newcastle-Ottawa Scale (NOS) was used to verify the quality of the evidence. Totally, 1682 patient cases were included. The odds ratio (OR) estimates and 95% confidence interval (CI) for each publication were determined by a fixed-effects (Mantel-Haenszel) model. A total of 20 studies that fulfilled the inclusion criteria were finally included in the analysis. The average score of quality evaluation was 6.4 points according to NOS. It was found that Ki67 levels were significantly higher in the NIH L group compared with the NIH VL group (OR: 0.51; 95% CI: 0.26-0.99; P=0.04; P heterogeneity=0.44). There was also greater Ki67 overexpression in the NIH I group compared with the NIH L group (OR: 0.45, 95% CI: 0.31-0.65; P<0.0001; P heterogeneity=0.32), while Ki67 levels were greater in the NIH H group than in the NIH I group (OR: 0.20; 95% CI: 0.15-0.28; P<0.00001; P heterogeneity=0.56). In conclusion, Ki67 overexpression may be a useful marker of the risk of recurrent GIST transformation.

Endoscopic management of subepithelial lesions including neuroendocrine neoplasms: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends endoscopic ultrasonography (EUS) as the best tool to characterize subepithelial lesion (SEL) features (size, location, originating layer, echogenicity, shape), but EUS alone is not able to distinguish among all types of SEL.Strong recommendation, moderate quality evidence. 2: ESGE suggests providing tissue diagnosis for all SELs with features suggestive of gastrointestinal stromal tumor (GIST) if they are of size > 20 mm, or have high risk stigmata, or require surgical resection or oncological treatment.Weak recommendation, very low quality evidence. 3: ESGE recommends EUS-guided fine-needle biopsy (EUS-FNB) or mucosal incision-assisted biopsy (MIAB) equally for tissue diagnosis of SELs ≥ 20 mm in size.Strong recommendation, moderate quality evidence. 4: ESGE recommends against surveillance of asymptomatic gastrointestinal (GI) tract leiomyomas, lipomas, heterotopic pancreas, granular cell tumors, schwannomas, and glomus tumors, if the diagnosis is clear.Strong recommendation, moderate quality evidence. 5: ESGE suggests surveillance of asymptomatic esophageal and gastric SELs without definite diagnosis, with esophagogastroduodenoscopy (EGD) at 3-6 months, and then at 2-3-year intervals for lesions < 10 mm in size, and at 1-2-year intervals for lesions 10-20 mm in size. For asymptomatic SELs > 20 mm in size that are not resected, ESGE suggests surveillance with EGD plus EUS at 6 months and then at 6-12-month intervals.Weak recommendation, very low quality evidence. 6: ESGE recommends endoscopic resection for type 1 gastric neuroendocrine neoplasms (g-NENs) if they grow larger than 10 mm. The choice of resection technique should depend on size, depth of invasion, and location in the stomach.Strong recommendation, low quality evidence. 7: ESGE suggests considering removal of histologically proven gastric GISTs smaller than 20 mm as an alternative to surveillance. The decision to resect should be discussed in a multidisciplinary meeting. The choice of technique should depend on size, location, and local expertise.Weak recommendation, very low quality evidence. 8: ESGE suggests that, to avoid unnecessary follow-up, endoscopic resection is an option for gastric SELs smaller than 20 mm and of unknown histology after failure of attempts to obtain diagnosis.Weak recommendation, very low quality evidence. 9: ESGE recommends basing the surveillance strategy on the type and completeness of resection. After curative resection of benign SELs no follow-up is advised, except for type 1 gastric NEN for which surveillance at 1-2 years is advised.Strong recommendation, low quality evidence. 10: For lower or upper GI NEN with a positive or indeterminate margin at resection, ESGE recommends repeating endoscopy at 3-6 months and another attempt at endoscopic resection in the case of residual disease.Strong recommendation, low quality evidence.

Unusual Gastrointestinal Hemorrhaging Mimicking a Rupture of Solitary Gastric Varices Due to a Gastric Gastrointestinal Stromal Tumor with Exogenous Growth

Gastric gastrointestinal stromal tumors can lead to upper gastrointestinal hemorrhaging, which is usually caused by dimpling or ulceration on the tumor surface. While rare, pedunculated gastric gastrointestinal stromal tumors outside the stomach can present as a huge mass with delayed complaints. We herein report an unusual hemorrhaging mimicking a rupture of solitary gastric varices due to a pedunculated gastric gastrointestinal stromal tumor. In this case, contrast-enhanced computed tomography (CECT) was essential for tumor detection. An endoscopic investigation revealed dilated, aberrant veins and arteries in the submucosa of this tumor, recognized as solitary gastric varices.

Spontaneous hemoperitoneum as a rare presentation of gastric lesions: Two case reports

Introduction

Spontaneous hemoperitoneum is a rare but life-threatening condition. Clinical presentation is usually nonspecific. The aim of this report is to document a rare clinical presentation of two different intramural stomach tumors.

Clinical cases

A 40-year-old patient with 24 h epigastric pain was admitted to the emergency, pale, with signs of peritoneal irritation. Computed tomography showed an hemoperitoneum with active bleeding in the posterior wall of the stomach. A wedge resection was performed. Histological report revealed a plexiform fibromyxoma (PF). The second case presents a 79-year-old patient with 24 h abdominal pain, fullness and dizziness, pale and with signs of peritoneal irritation. A voluminous exophytic lesion on gastric wall with active bleeding was diagnosed. Wedge resection was performed and histological report demonstrated a gastrointestinal stromal tumor (GIST).

Discussion

Imaging plays a role in the diagnosis of spontaneous hemoperitoneum, in elucidating a cause and detecting active hemorrhage. Tumor hemorrhage may be the first presentation of an underlying mass. The presence of a bleeding gastric mass of uncertain nature may result in a challenging situation for the surgeon, who is forced to perform a gastric resection without knowing the exact nature of the tumor and hence the extent of gastric resection required. To our knowledge, our case is the first of PF presenting as hemoperitoneum. Hemoperitoneum is rare as first presentation of GIST, with few cases reported in literature.

Conclusion

We report two extremely rare cases of spontaneous hemoperitoneum as first presentation of gastric tumor. For the diagnosis a high level of suspicion is required.

•

Spontaneous hemoperitoneum is a rare but life-threatening condition.

•

Tumor hemorrhage may be the first presentation of an underlying gastric mass.

•

This is the first case of Plexiform fibromyxoma (PF) presenting as hemoperitoneum.

[Gastrointestinal stromal tumors: potential of minimally invasive surgical interventions]

OBJECTIVE

To analyze the issue of gastrointestinal stromal tumors (GISTs) and potential of minimally invasive surgical interventions.

MATERIAL AND METHODS

We analyzed postoperative outcomes in 97 patients with gastric and intestinal GISTs who underwent surgical treatment at the National Medical Research Centre for Oncology between 2015 and 2020.

RESULTS

Twenty (24.7) patients with gastric GISTs underwent laparoscopic partial and distal gastric resections. Five (35.7%) patients with GISTs of the small intestine underwent minimally invasive segmental bowel resections. Only minimally invasive interventions were performed in patients with rectal GISTs. Analysis of laparoscopic and open surgeries for GISTs found no significant differences. Analysis of laparoscopic and open surgeries for gastric and small bowel GISTs revealed the obvious advantages of minimally invasive access regarding postoperative outcomes. Indeed, we found no need for nasogastric drainage in 50% of patients (p<0.001), earlier recovery of intestinal motility and oral feeding (p<0.001), lower postoperative morbidity (p=0.036), fast recovery of motor activity (p<0.001) and shorter postoperative hospital-stay (p<0.001).

CONCLUSION

Despite small incidence, GISTs are a complex problem in modern oncology. Diagnosis and treatment require a multidisciplinary medical team (morphologists, geneticists, radiologists, surgeons, chemotherapists, gastroenterologists and other specialists) that is possible in a reference center. Minimally invasive interventions for GISTs of the stomach, small intestine and rectum improve postoperative course.

Postoperative Adjuvant Imatinib Therapy-Associated Nomogram to Predict Overall Survival of Gastrointestinal Stromal Tumor

BACKGROUND

Adjuvant imatinib therapy has been shown to improve overall survival (OS) of gastrointestinal stromal tumor (GIST) significantly. Few nomograms combining the use of adjuvant imatinib and clinicopathological characteristics estimate the outcome of patients. We aimed to establish a more comprehensive nomogram for predicting OS in patients with GIST.

METHODS

In total, 1310 GIST patients undergoing curative resection at four high-volume medical centers between 2001 and 2015 were enrolled. Independent prognostic factors were identified by multivariate Cox analysis. Eligible patients were randomly assigned in a ratio of 7:3 into a training set (916 cases) and a validation set (394 cases). A nomogram was established by R software and its predictive power compared with that of the modified National Institutes of Health (NIH) classification using time-dependent receiver operating characteristic (ROC) curves and calibration plot.

RESULTS

Age, tumor site, tumor size, mitotic index, postoperative imatinib and diagnostic delay were identified as independent prognostic parameters and used to construct a nomogram. Of note, diagnostic delay was for the first time included in a prognostic model for GIST. The calibrated nomogram resulted in predicted survival rates consistent with observed ones. And the decision curve analysis suggested that the nomogram prognostic model was clinically useful. Furthermore, time-dependent ROC curves showed the nomogram exhibited greater discrimination power than the modified NIH classification in 3- and 5-year survival predictions for both training and validation sets (all P < 0.05).

CONCLUSIONS

Postoperative adjuvant imatinib therapy improved the survival of GIST patients. We developed and validated a more comprehensive prognostic nomogram for GIST patients, and it could have important clinical utility in improving individualized predictions of survival risks and treatment decision-making.

Survival trends in gastric cancer patients between 1987 and 2016: a population-based cohort study in Finland

BACKGROUND

Gastric cancer is the fourth leading cause of cancer-related deaths globally. There is a paucity of national studies examining gastric cancer mortality in relation to treatment status. This study evaluated the survival trends in gastric adenocarcinoma and all gastric cancers stratified by treatment in Finland during 1987-2016.

METHODS

This population-based, nationwide, retrospective cohort study included all gastric cancer patients registered in the Finnish Cancer Registry and Patient Registry. The survival rates were calculated for 1, 3, and 5 years, stratified by treatment. Prognostic factors were determined using Cox regression.

RESULTS

A total of 18,713 non-cardia gastric adenocarcinoma, and 3617 cardia adenocarcinoma patients were included. Surgical treatment decreased for non-cardia adenocarcinoma and remained constant for cardia adenocarcinoma. In non-cardia adenocarcinoma, the 5-year survival declined from 17% to 16% from 1987-1991 to 2012-2016. In surgically treated patients, survival increased from 29% to 38%, while an increase from 4% to 7% in those undergoing chemotherapy and decrease from 6% to 3% in those not receiving any treatment were observed. In cardia adenocarcinoma, the 5-year survival increased from 10% to 18% in all patients, 16% to 40% in surgical patients, 0% to 5% in patients receiving chemotherapy, and from 5% to 9% in patients receiving no treatment. Earlier calendar periods, older age, male sex, and higher comorbidity were risk factors for poor prognosis.

CONCLUSIONS

Gastric non-cardia adenocarcinoma survival declined, limited to advanced stage patients not receiving any treatment. Gastric cardia cancer survival seems to have improved over time in Finland. This study evaluated survival trends of gastric cancer in Finland during 1987-2016 and established that the 5-year survival is declining in non-cardia adenocarcinoma but improving in all gastric cancers.

Primary Localized Gastrointestinal Stromal Tumors: Medication Adherence and Prognosis According to Gender

OBJECTIVE

Gender is associated with medication adherence for imatinib, but whether it is related to the prognosis of primary localized gastrointestinal stromal tumors (GISTs) is unclear. The goal of this study was to clarify the relationship between gender and prognosis in GIST patients, with differences in medication adherence considered.

METHODS

The data of 320 GIST patients were retrospectively collected from the First Affiliated Hospital of Chongqing Medical University. Survival analysis was performed using the Kaplan-Meier method (Log rank test) and the risk factors of recurrence were determined using Cox multivariate analysis. Medication adherence-stratified analyses were performed to control for confounding factors.

RESULTS

Kaplan-Meier analysis revealed that among patients who received postoperative adjuvant imatinib therapy, men had a higher recurrence rate than women (P<0.01). Pearson's chi-square test revealed better medication adherence in women than in men (P<0.01). Cox regression analysis revealed that gender was not an independent risk factor for recurrence-free survival (RFS; P=0.25), but medication adherence was (P<0.01). Among GIST patients with a medication possession ratio (MPR) of less than 90%, 62.86% of male patients took imatinib irregularly or not at all due to limited understanding of the disease, whereas 55.74% of female patients' took imatinib irregularly because they could not tolerate adverse drug reactions.

CONCLUSION

Adherence was poorer in male than in female patients, which might explain the worse prognoses of the former among patients who received adjuvant treatment with imatinib. The gender difference in the degree of adherence should be considered in postoperative pharmacotherapy for patients with primary localized GISTs.

A rare case of extraluminally pedunculated gastrointestinal stromal tumor with postoperative metastasis to pancreas

The gastrointestinal stromal tumor (GIST) is the most common type of sarcomatous tumor of the gastrointestinal tract. Many GISTs appear as submucosal tumors with intraluminal protrusion. GISTs with malignant features have a high risk of postoperative recurrence or metastasis, usually to the liver or peritoneum. We present a case of gastric GIST with double rarities: arising completely extraluminally with a pedicle and postoperative metastasis to the pancreas. A woman in her seventies diagnosed with a large extraluminal gastric GIST underwent complete removal of the tumor. Nine months later, a solitary metastatic tumor in the pancreas was detected. Imatinib controlled metastasis well for four years before the tumor became resistant. The patient then had a partial pancreatectomy with splenectomy. She is currently free from recurrence. We genetically analyzed the primary and metastatic GISTs and found known mutations related to poor prognosis and imatinib resistance.

Robotic resection of duodenal gastrointestinal stromal tumour: Preliminary experience from a single centre

BACKGROUND

Experience in minimally invasive surgery in the treatment of duodenal gastrointestinal stromal tumors (DGISTs) is accumulating, but there is no consensus on the choice of surgical method.

AIM

To summarize the technique and feasibility of robotic resection of DGISTs.

METHODS

The perioperative and demographic outcomes of a consecutive series of patients who underwent robotic resection and open resection of DGISTs between May 1, 2010 and May 1, 2020 were retrospectively analyzed. The patients were divided into the open surgery group and the robotic surgery group. Pancreatoduodenectomy (PD) or limited resection was performed based on the location of the tumour and the distance between the tumour and duodenal papilla. Age, sex, tumour location, tumour size, operation time (OT), estimated blood loss (EBL), postoperative hospital stay (PHS), tumour mitosis, postoperative risk classification, postoperative recurrence and recurrence-free survival were compared between the two groups.

RESULTS

Of the 28 patients included, 19 were male and 9 were female aged 51.3 ± 13.1 years. Limited resection was performed in 17 patients, and PD was performed in 11 patients. Eleven patients underwent open surgery, and 17 patients underwent robotic surgery. Two patients in the robotic surgery group underwent conversion to open surgery. All the tumours were R0 resected, and there was no significant difference in age, sex, tumour size, operation mode, PHS, tumour mitosis, incidence of postoperative complications, risk classification, postoperative targeted drug therapy or postoperative recurrence between the two groups (P > 0.05). OT and EBL in the robotic group were significantly different to those in the open surgery group (P < 0.05). All the patients survived during the follow-up period, and 4 patients had recurrence and metastasis. No significant difference in recurrence-free survival was noted between the open surgery group and the robotic surgery group (P > 0.05).

CONCLUSION

Robotic resection is safe and feasible for patients with DGISTs, and its therapeutic effect is equivalent to open surgery.

Value of radiomics model based on enhanced computed tomography in risk grade prediction of gastrointestinal stromal tumors

To explore the application of computed tomography (CT)-enhanced radiomics for the risk-grade prediction of gastrointestinal stromal tumors (GIST). GIST patients (n = 292) confirmed by surgery or endoscopic pathology during June 2013–2019 were reviewed and categorized into low-grade (very low to low risk) and high-grade (medium to high risk) groups. The tumor region of interest (ROI) was depicted layer by layer on each patient’s enhanced CT venous phase images using the ITK-SNAP. The texture features were extracted using the Analysis Kit (AK) and then randomly divided into the training (n = 205) and test (n = 87) groups in a ratio of 7:3. After dimension reduction by the least absolute shrinkage and the selection operator algorithm (LASSO), a prediction model was constructed using the logistic regression method. The clinical data of the two groups were statistically analyzed, and the multivariate regression prediction model was constructed by using statistically significant features. The ROC curve was applied to evaluate the prediction performance of the proposed model. A radiomics-prediction model was constructed based on 10 characteristic parameters selected from 396 quantitative feature parameters extracted from the CT images. The proposed radiomics model exhibited effective risk-grade prediction of GIST. For the training group, the area under curve (AUC), sensitivity, specificity, and accuracy rate were 0.793 (95%CI: 0.733–0.854), 83.3%, 64.3%, and 72.7%, respectively; the corresponding values for the test group were 0.791 (95%CI: 0.696–0.886), 84.2%, 69.3%, and 75.9%, respectively. There were significant differences in age (t value: − 3.133, P = 0.008), maximum tumor diameter (Z value: − 12.163, P = 0.000) and tumor morphology (χ² value:10.409, P = 0.001) between the two groups, which were used to establish a clinical prediction model. The area under the receiver operating characteristic curve of the clinical model was 0.718 (95%CI: 0.659–0.776). The proposed CT-enhanced radiomics model exhibited better accuracy and effective performance than the clinical model, which can be used for the assessment of risk grades of GIST.

Gastrointestinal stromal tumor in ruptured Meckel's diverticulum located in jejunum caused myelosuppression for a short time: A case report

INTRODUCTION AND IMPORTANCE

Gastrointestinal stromal tumor (GIST) in Meckel's diverticulum (MD) is rare but it seems to be a common phenomenon that GIST triggers MD perforation or rupture; the exact mechanism is unclear. In addition, the location of GIST in perforated or ruptrued MD is most common in ileum, rarely in jejunum. We herein report a GIST in ruptured MD Located in jejunum and severe peritoneal cavity infection leads to myelosuppression.

CASE PRESENTATION

A female patient was admitted to our hospital with "abdominal pain". Physical examination and laboratory tests revealed that the patient was in shock and myelosuppression. Abdominal X-ray photograph and computed tomography indicated perforation of digestive tract. Laparotomy revealed rupture of MD located 90 cm from the Treitz ligament and a tumor was also found in the MD. As the condition is critical, the MD was excisioned from its root and the small bowel gap was closed and repaired. Laboratory indicators showed that myelosuppression was removed 24 h after operation. The pathological findings established a GIST in the MD. The patient was discharged on postoperative day 5 without significant complications.

CLINICAL DISCUSSION

A GIST in ruptured MD Located in jejunum caused the severe peritoneal cavity infection and myelosuppression In a short time, as seen in this case. Failure to recognize the severity of the disease and delay in treatment will endanger the life of the patient.

CONCLUSION

GIST in MD Located in jejunum is very rare, and the rupture of the MD can be life-threatening at any time.

Outcome, prognostic factors and histological characterization of canine gastrointestinal sarcomas

Canine gastrointestinal sarcomas, a group of tumours that includes leiomyosarcomas (LMSAs), gastrointestinal stromal tumours (GISTs) and other rarer sarcomas, comprise about 10-30% of all gastrointestinal tumours. This study aims to characterize the histologic characteristics and clinical behaviour in order to identify prognostic factors predictive of outcome. A single institution database search for surgically treated gastrointestinal sarcomas yielded 47 cases with adequate tissue remaining for histologic analysis and 42 cases available for analysis of clinical outcome. Tumours were then prospectively evaluated for mitotic count, necrosis, haemorrhage and inflammation, as well as categorized via immunohistochemical (IHC) staining for smooth muscle actin, c-KIT and DOG-1. IHC analysis defined 32 tumours as GISTs, 14 as LMSAs and one as a sarcoma not otherwise specified. For both GISTs and LMSAs, the overall median survival time (MST) is 1024 days (range 31-1456), which did not differ statistically between tumour types (p = .92). The overall metastatic rate of GISTs in this study was 32.1% (n = 9) which was not significantly different to that of LMSAs at 15.3% (n = 2, p = .45). In multivariate analysis, mitotic count under 9 in GIST patients and complete surgical excision in all tumour types correlated with improved MST. For patients with GISTs, the intensity of c-KIT staining also correlated positively with survival, with an MST of 250 days in cases with weak staining and an MST of 1418 days in cases with moderate or strong c-KIT staining (p = .005).

Preoperative Diagnosis Failure for a Rare Gastric Collision Tumor: A Case Report

Gastrointestinal stromal tumors (GISTs) are common mesenchymal tumors of the gastrointestinal tract (GIT), usually occur as a solitary neoplasm. Inflammatory florid polyp (IFP) is a solitary rare benign lesion of the gastrointestinal tract, mainly occur in the gastric antrum, whose atypical presentation can mimic GISTs or other malignant tumors, therefore the synchronous occurrence of GISTs and IFP is extremely rare. We had a case of a 58-year-old man that was presented with recurrent epigastric pain and recurrent melena. Upper endoscopic examination revealed a large polypoid antrum polyp measured 7 cm at greatest dimension with focal ulceration. Clinical and radiological features did not reach the definite diagnosis until histopathological evaluation with immunohistochemical analysis was performed. Surgical intervention is recommended and partial gastrectomy was done with wide resection margins. Histological examination revealed two distinct GISTs and IFP parts presenting a collision tumor that showed spindle and epitheloid cells consistent with GISTs with histological features of florid polyp showed a characteristic perivascular onion-skin arrangement of spindle cells with dense chronic inflammatory infiltrate including eosinophils and lymphocytes. Immunohistochemical studies have been done and revealed an association between GISTs and IFP. To the best of our knowledge, this is the first case of a collision tumor consisting of a GIST and an IFP arising in the stomach. In conclusion, the gastrointestinal stromal tumor is the comments mesenchymal tumor of GIT and IFP is a rare benign lesion of GIT therefore association between GIST and IFP as a collision tumor is extremely rare.

Improved understanding of gastrointestinal stromal tumors biology as a step for developing new diagnostic and therapeutic schemes

A gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal tract, with an estimated incidence of 10-15 per 1 million per year. While preparing holistic care for patients with GIST diagnosis, scientists might face several difficulties - insufficient risk stratification, acquired or secondary resistance to imatinib, or the need for an exceptional therapy method associated with wild-type tumors. This review summarizes recent advances associated with GIST biology that might enhance diagnostic and therapeutic strategies. New molecules might be incorporated into risk stratification schemes due to their proven association with outcomes; however, further research is required. Therapies based on the significant role of angiogenesis, immunology, and neural origin in the GIST biology could become a valuable enhancement of currently implemented treatment schemes. Generating miRNA networks that would predict miRNA regulatory functions is a promising approach that might help in better selection of potential biomarkers and therapeutical targets in cancer, including GISTs.

Gastrointestinal Stromal Tumor in Monozygotic Twins Shows Distinct Mutational Status: A Case Report

Case series

Patients: Female, 62-year-old • Female, 62-year-old

Final Diagnosis: Gastrointestinal stromal tumor (GIST)

Symptoms: Abdominal pain • fatigue

Medication: —

Clinical Procedure: Genetic analysis

Specialty: Oncology

The Role of the Pathologist in the Next-Generation Era of Tumor Molecular Characterization

Current pathology practice is being shaped by the increasing complexity of modern medicine, in particular of precision oncology, and major technological advances. In the "next-generation technologies era", the pathologist has become the person responsible for the integration and interpretation of morphologic and molecular information and for the delivery of critical answers to diagnostic, prognostic and predictive queries, acquiring a prominent position in the molecular tumor boards.

Solitary peritoneal metastasis of gastrointestinal stromal tumor: A case report

BACKGROUND

A gastrointestinal stromal tumor (GIST) is a mesenchymal tumor of the gastrointestinal tract that is most commonly found in the stomach. Recurrence of GISTs mostly occurs in the liver or peritoneum, and in most cases, multiple metastases occur. As a solitary peritoneal metastasis is rare, an appropriate treatment strategy has not been established. Here, we report a case of solitary peritoneal metastasis after complete resection of gastric GIST.

CASE SUMMARY

A 76-year-old woman was diagnosed with stomach GIST and underwent laparoscopic local resection using the CLEAN-NET method. As the recurrence risk was intermediate, adjuvant imatinib therapy was not administered. Two years after surgery, routine computed tomography revealed an abdominal mass between the dorsal side of the right hepatic lobe and right kidney. Other imaging tests did not reveal any abnormalities. Laparoscopic observation showed that the tumor was located at the retroperitoneum, and intraperitoneal dissemination was not found. Therefore, we performed laparoscopic tumor resection. Immunohistochemically, the tumor was positive for c-kit and CD34 and had a relatively high mitotic index and MIB-1 Labeling index. We administered adjuvant imatinib therapy. There was no evidence of recurrence 3 years after the operation.

CONCLUSION

This is the first reported case of a solitary recurrence of GIST in the peritoneum treated with complete laparoscopic resection.