Diagnostic and treatment strategy for small gastrointestinal stromal tumors

A population-based analysis of gender differences in survival outcomes for gastric gastrointestinal stromal tumors

BACKGROUND

Although gender-based differences have been demonstrated to affect the prognosis of multiple tumors, their specific influence on the survival of gastric gastrointestinal stromal tumors (gGISTs) at the population level is still uncertain. Consequently, we aimed to investigate gender disparities in the prognosis of gGISTs using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Patients with gGISTs from the years 2000 to 2019 were retrieved from the SEER database. To minimize selection bias, propensity score matching (PSM) was used. Kaplan-Meier analyses and Cox proportional hazard models were used to assess the influence of clinical characteristics on overall survival (OS) and cancer-specific survival (CSS).

RESULTS

A total of 3006 patients with gGISTs were analyzed, including 1459 males and 1547 females. Compared with female patients, male patients exhibited a higher proportion of Whites, more advanced T stage, larger tumor sizes, and elevated mitotic index. Before PSM, male patients experienced significantly worse OS (hazard ratio [HR], 1.55; 95% CI, 1.33-1.81; P <.001) and CSS outcomes (HR, 1.61; 95% CI, 1.28-2.02; P <.001) than female patients. Furthermore, they had lower mean OS and CSS rates at the 1-, 3-, and 5-year follow-up intervals (P <.05). Even after PSM, male patients continued to show poorer OS (HR, 1.30; 95% CI, 1.10-1.54; P =.002) and CSS outcomes (HR, 1.34; 95% CI, 1.05-1.70; P =.016) than female patients, with persistently lower mean OS and CSS rates across the 1-, 3-, and 5-year follow-up intervals (P <.05). For males without distant metastasis, 5-year OS was 78.8% and CSS was 90.0%, both lower than females' 85.5% and 93.7% (P <.05). For males with distant metastasis, 5-year OS was 48.7% and CSS was 58.8%, similar to females' 55.4% and 65.3% (P >.05). Multivariate Cox regression analysis identified age, race, gender, M stage, surgical intervention, tumor size, and mitotic index as independent risk factors for both OS and CSS.

CONCLUSION

Patients with gGISTs exhibit distinct clinical characteristics between males and females, with female patients showing a tendency toward improved OS and CSS. Surgical treatment has the potential to enhance the prognosis of patients with gGISTs.

Defining Textbook Outcomes for Minimally Invasive Surgical Resection of Small Gastrointestinal Stromal Tumors (GIST) of the Stomach

BACKGROUND

Textbook outcome (TO) has been utilized to assess the quality of surgical care. This study aimed to define TO rates for minimally invasive gastric gastrointestinal stromal tumor (GIST) resections in a bi-institutional cohort.

METHODS

Patients with gastric GIST (≤ 5 cm) who underwent laparoscopic or robotic resection (January 2014 to January 2024) were retrospectively identified from two GIST centers. We excluded patients with concurrent procedures, tumor involvement of adjacent organs, or metastatic disease. To balance perioperative and oncologic outcomes, we defined TO as: R0 resection, no conversion to open surgery, operative time ≤ 120 min, no perioperative transfusions, no intraoperative complications, no Clavien-Dindo ≥ II complications, hospital length of stay (LOS) ≤ 3 days, no 90-day readmission or death, no tumor rupture, and recurrence-free status at 2 years (5% predicted recurrence risk for tumors with a low mitotic index).

RESULTS

A total of 83 patients were included. TO was achieved in 62.7% of cases (N = 52). Mean tumor size was 3.0 ± 1.0 cm and 86.7% of GIST were modified-NIH low or very low risk (i.e., mitotic index ≤5/mm2). Mean operative time was 102.7 ± 49.3 minutes. Mean LOS was 2.3 ± 1.2 days. Among non-TO cases, the most common disqualifying factors were operative time > 120 minutes (N = 20, 24.1%) and LOS > 3 days (N = 15, 18.1%). There were four 90-day readmissions (4.8%) and one case with staple line bleeding requiring endoscopic clipping. During a mean follow-up of 32.6 ± 24.1 months, 3 patients (3.6%) recurred within 2 years. On multivariable regression analysis, no factors were independently associated with non-TO.

CONCLUSIONS

Minimally invasive gastric GIST resection is well-described. Herein, we propose new TO standards to serve as a measure of short- and long-term outcomes for monitoring institutional performance.

Reopenable clip over-the-line method in endoscopic full-thickness resection of gastric submucosal tumors: A historical control study

OBJECTIVES

Endoscopic full-thickness resection for gastric submucosal tumors is gradually gaining popularity, and secure and amenable closure is key to its success. This study aimed to compare the reopenable clip over-the-line method with the purse-string method for defect closure after endoscopic full-thickness resection for gastric submucosal tumors.

METHODS

This historical control trial included 37 consecutive patients with 37 gastric submucosal tumors, who underwent endoscopic full-thickness resection between January 2021 and July 2024. All lesions were resected en bloc. After excluding three patients who underwent non-full-thickness resection, 34 patients were analyzed. Post-endoscopic full-thickness resection defects were closed using the purse-string method (n = 18) until 2022 and the reopenable clip over-the-line method (n = 16) from 2023.

RESULTS

The median (interquartile range) time for defect closure was longer in the reopenable clip over-the-line method group of 33 (31-57) min than in the purse-string method group of 26 (24-35) min (p = 0.013). The visual analog scale pain score at the umbilical region was lower (p = 0.048) after the reopenable clip over-the-line method than after the purse-string method. In the reopenable clip over-the-line method group, post-procedural abdominal pain was confined to the epigastrium, whereas it extended to the umbilical or left lateral regions in the purse-string method group. The reopenable clip over-the-line method group commenced the diet (p = 0.001) and discharged (p = 0.024) earlier than the purse-string method group.

CONCLUSIONS

Reopenable clip over-the-line method facilitated secure post-endoscopic full-thickness resection defect closure, reduced post-procedural abdominal pain, and shortened the fasting and hospitalization periods after endoscopic full-thickness resection in gastric submucosal tumors.

Surgical resection for small (≤2 cm) gastric gastrointestinal stromal tumor

BACKGROUND

It is unclear whether surgical excision is the best course of treatment for small gastric gastrointestinal stromal tumor (GIST) ≤2 cm. The aim of this study was to evaluate the long-term survival results of surgical and non-surgical treatment for small gastric GIST.

METHODS

Between 2000 and 2021, patients with small gastric GIST were chosen from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was used to mitigate selection bias in the comparison process. Kaplan-Meier analysis and multivariate Cox model were used to assess the effects of demographic and clinical characteristics on overall survival (OS) and cancer-specific survival (CSS).

RESULTS

A total of 1229 patients with gastric GIST (≤2 cm) were included, including 1004 (81.69 %) patients who underwent operative management and 225 (18.31 %) who received non-operative management. The 5-year OS and CSS rates were compared between the two groups before PSM [5-year OS (83.51 % vs. 79.53 %, P < 0.001), 5-year CSS (96.96 % vs. 91.81 %, P = 0.017)]; after PSM [5-year OS (82.79 % vs. 80.00 %, P = 0.039), and 5-year CSS (94.88 % vs. 94.42 %, P = 0.398)]. Furthermore, after correcting for covariates, operative management was associated with a significant improvement in OS (HR = 0.62, 95 % CI 0.40-0.97, P = 0.037), while no significant effect on CSS was observed (HR = 0.85, 95 % CI 0.43-1.70, P = 0.643).

CONCLUSIONS

Our analysis demonstrated a statistically significant association between operative management and improved OS for small gastric GIST (≤2 cm).

Feasibility study of synchronously increasing dose of multi-shell structure to improve stereotactic ablation radiotherapy central dose of large volume locally advanced gastrointestinal stromal tumors using cyberKnife

Purpose. Increasing the central dose for large, locally advanced, drug-resistant gastrointestinal stromal tumors (LADR-GISTs) has consistently been a significant challenge. This study explores the feasibility of using multiple shell structures within the tumor to enhance the central ablation dose of large LADR-GIST by increasing the shell doses.Methods and Materials. This study involved five patients with large LADR-GIST who were treated with CyberKnife. The gross tumor volume (GTV) was delineated as a multi-shell structure. Five dose escalation plans (SIB-SBRT) were created for each patient, varying the dose escalation ratios. The radiation doses for the center of the GTV (GTV center) in these plans ranged from 49 Gy to 70 Gy. Parameter evaluations were conducted comparing the SIB-SBRT plans with conventional SBRT plans (Con-SBRT), focusing on equivalent uniform dose (EUD), relative equivalent uniform dose (rEUD), dose volume parameters, conformal index (CI), new conformal index (nCI), gradient index (GI), and monitor unit (MU). The Friedman Test was employed to determine statistical differences (P< 0.05), followed by pairwise comparisons.Results. When the dose escalation ratios reached 25% of the prescribed dose, the average rEUD increased to 6.92, and the proportion of the GTV volume with Biologically Equivalent Dose (BED)> 100 Gy increased to 30.69%. At dose escalation ratios of 30% of the prescribed dose, the rEUD stabilized, but the radiation dose received by the bladder, colon, and duodenum significantly increased. Except for the SIB25-SBRT and SIB30-SBRT groups, no statistically significant differences were observed between the other SIB-SBRT groups and the Con-SBRT group across various evaluation metrics.Conclusions. The method of synchronously increasing the dose using a multi-shell structure is feasible for stereotactic ablation in the treatment of LADR-GISTs using CyberKnife. The results indicate that dose escalation ratios of 25% of the prescribed dose can provide a satisfactory ablation dose (BED > 100 Gy), covering 31% of the large tumor volume.

Ileal Gastrointestinal Stromal Tumor (GIST) Presenting With a Liver Abscess: A Case Report and Review of the Literature

Gastrointestinal stromal tumors (GISTs) are rare small intestinal tumors. Due to challenging diagnoses, the majority of patients typically report chronic problems. Early diagnosis and the start of appropriate treatment depend on high suspicion. We present a case of a 47-year-old male patient who first experienced fever, nausea, vomiting, and pain in the right upper quadrant. Radiologic examinations showed an intra-abdominal tumor containing oral contrast and a liver lesion, indicating gastrointestinal tract involvement. He had an ileal GIST that created a fistula between the tumor and the small intestine, complicated by a liver abscess. We surgically removed the tumor and intra-operatively drained the liver abscess. A liver lesion found in conjunction with a small intestine GIST should cause concern for both the possibility of infectious complications such as a pyogenic liver abscess and metastatic illness. The uncommon appearance of an ileal GIST with a tumor-intestinal fistula, accompanied by a liver abscess, is reviewed in this case report.

Deep learning model combined with computed tomography features to preoperatively predicting the risk stratification of gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GIST) are prevalent neoplasm originating from the gastrointestinal mesenchyme. Approximately 50% of GIST patients experience tumor recurrence within 5 years. Thus, there is a pressing need to accurately evaluate risk stratification preoperatively.

AIM

To assess the application of a deep learning model (DLM) combined with computed tomography features for predicting risk stratification of GISTs.

METHODS

Preoperative contrast-enhanced computed tomography (CECT) images of 551 GIST patients were retrospectively analyzed. All image features were independently analyzed by two radiologists. Quantitative parameters were statistically analyzed to identify significant predictors of high-risk malignancy. Patients were randomly assigned to the training (n = 386) and validation cohorts (n = 165). A DLM and a combined DLM were established for predicting the GIST risk stratification using convolutional neural network and subsequently evaluated in the validation cohort.

RESULTS

Among the analyzed CECT image features, tumor size, ulceration, and enlarged feeding vessels were identified as significant risk predictors (P < 0.05). In DLM, the overall area under the receiver operating characteristic curve (AUROC) was 0.88, with the accuracy (ACC) and AUROCs for each stratification being 87% and 0.96 for low-risk, 79% and 0.74 for intermediate-risk, and 84% and 0.90 for high-risk, respectively. The overall ACC and AUROC were 84% and 0.94 in the combined model. The ACC and AUROCs for each risk stratification were 92% and 0.97 for low-risk, 87% and 0.83 for intermediate-risk, and 90% and 0.96 for high-risk, respectively. Differences in AUROCs for each risk stratification between the two models were significant (P < 0.05).

CONCLUSION

A combined DLM with satisfactory performance for preoperatively predicting GIST stratifications was developed using routine computed tomography data, demonstrating superiority compared to DLM.

Patterns of Care and Outcomes of Patients with Small Gastrointestinal Stromal Tumors at a High-Volume Sarcoma Center

BACKGROUND

The course of subclinical gastrointestinal stromal tumors (GISTs) is variable. The management of small GISTs is not well-defined.

METHODS

Records of patients presenting with small GISTs with documented follow-up appointment at our institution between 2016 and 2022 were identified and reviewed. Comparative univariate analysis to compare patient and tumor characteristics and outcomes was performed.

RESULTS

Eighty-six patients were followed for a median of 3.7 years (range 0.1-20 years). The median size at presentation was 1.7 (range 0.1-2.5) cm. A total of 51.2% (n = 44) underwent surgery before or immediately after initial presentation for pain (18.2%), bleeding (15.9%), or patient preference (6.8%). Another 17.4% (n = 15) had delayed surgery for tumor growth (40%), patient preference (2.7%), bleeding (6.7%), or pain (6.7%). The remaining 31.4% (n = 27) of patients never underwent surgery for reasons that included no growth/stability (44.4%), concomitant cancer diagnosis/treatment (29.6%), comorbidities (14.8%), and patient preference (3.7%). Patients who underwent surveillance without intervention compared with those who had delayed surgery were older (71.1 vs. 60.8 years, p < 0.001) with multiple comorbidities or a concurrent cancer diagnosis (70.3% vs. 20%, p = 0.005). There were no differences in survival or rate of distant metastases. Average time to surgery in the delayed group was 2 (range 0.1-10.3) years, and 86% of these patients underwent surgery by 5.5 years after diagnosis.

CONCLUSIONS

In older patients with comorbidities or concurrent cancer diagnoses, opting out of surgery does not affect survival. Conversely, younger patients, free from significant comorbidities or other diagnoses, may consider surgery or active surveillance for up to 5 years, with comparable outcomes.

Gene Mutations in Gastrointestinal Stromal Tumors: Advances in Treatment and Mechanism Research

Although gastrointestinal stromal tumors (GISTs) has been reported in patients of all ages, its diagnosis is more common in elders. The two most common types of mutation, receptor tyrosine kinase (KIT) and platelet-derived growth factor receptor a (PDGFRA) mutations, hold about 75 and 15% of GISTs cases, respectively. Tumors without KIT or PDGFRA mutations are known as wild type (WT)-GISTs, which takes up for 15% of all cases. WT-GISTs have other genetic alterations, including mutations of the succinate dehydrogenase and serine-threonine protein kinase BRAF and neurofibromatosis type 1. Other GISTs without any of the above genetic mutations are named "quadruple WT" GISTs. More types of rare mutations are being reported. These mutations or gene fusions were initially thought to be mutually exclusive in primary GISTs, but recently it has been reported that some of these rare mutations coexist with KIT or PDGFRA mutations. The treatment and management differ according to molecular subtypes of GISTs. Especially for patients with late-stage tumors, developing a personalized chemotherapy regimen based on mutation status is of great help to improve patient survival and quality of life. At present, imatinib mesylate is an effective first-line drug for the treatment of unresectable or metastatic recurrent GISTs, but how to overcome drug resistance is still an important clinical problem. The effectiveness of other drugs is being further evaluated. The progress in the study of relevant mechanisms also provides the possibility to develop new targets or new drugs.

Clinical importance of tumor rupture in gastrointestinal stromal tumor

Risk factors of gastrointestinal stromal tumors (GISTs) include tumor size, location, mitosis, and tumor rupture. Although the first three are commonly recognized as independent prognostic factors, tumor rupture is not a consistent finding. Indeed, tumor rupture may be subjectively diagnosed and is rarely observed. Moreover, the criteria used for diagnosis differ among oncologists, which may result in inconsistent outcomes. Based on these conditions, a universal definition of tumor rupture was proposed in 2019 and consists of six scenarios: tumor fracture, blood-stained ascites, gastrointestinal perforation at the tumor site, histologically proven invasion, piecemeal resection, and open incisional biopsy. Although the definition is considered appropriate for selection of GISTs with worse prognostic outcomes, each scenario lacks a high level of evidence and there is yet no consensus for some, including histological invasion and incisional biopsy. It may be, however, important to have common criteria for clinical decision-making, which may facilitate reliability, external validity, and comparability of clinical studies in rare GISTs. After the definition, several retrospective reports indicated that even with adjuvant therapy, tumor rupture was associated with high recurrence rates and poor prognostic outcomes. The prognosis of patients with ruptured GISTs is improved by 5-year adjuvant therapy compared with 3-year therapy. Nevertheless, the universal definition requires further evidence, and prospective clinical studies based on the definition are warranted.

Safety and efficacy of a modified endoscopic full-thickness resection technique for gastric submucosal tumors: a case series

Objectives

Endoscopic full-thickness resection (EFTR) has proven effective and economical for patients with gastric submucosal tumors (SMTs). However, the poor operative field of view, the risk of massive hemorrhage, and the difficulties in defect closure have limited its widespread application. Herein, we described a modified EFTR technique developed to simplify the dissection and defect closure procedures using common and economical endoscopic accessories.

Methods

Forty-two patients who underwent the modified EFTR for gastric SMTs in the Shenzhen Guangming District People's Hospital were enrolled in the case series. Following a cross incision to expose the intraluminal surface the tumors were captured by suction through a transparent cap and the roots were ligated using a loop. The tumors and part of the suction tissue were removed along the ligated root. A tension-relieving closure was performed by clipping the raised plica in four quadrants outside the ligated root. Patient demographics, tumor characteristics, and therapeutic outcomes were evaluated retrospectively.

Results

All tumors had an R0 resection. The median procedure time was 51.8 min (IQR 34.25 min). No severe perioperative adverse events occurred. No residual lesion or recurrence was reported during the follow-up period of 9.84 months (IQR 5.0 months).

Conclusion

The safety and practicability of Modified-EFTR could allow for wide clinical application in patients with micro-gastric SMTs.

Clinical course of small gastric subepithelial lesion less than 20 mm diagnosed by endoscopic ultrasound-guided fine-needle aspiration

BACKGROUND AND AIM

Gastrointestinal stromal tumors (GISTs) are treated as malignant gastric subepithelial lesions (SELs), and resection is recommended. However, small gastric SELs < 20 mm with no malignant features are monitored without histopathological examination, and the frequency of malignancy is unknown. This study aimed to clarify the clinicopathological findings and clinical course of gastric SELs < 20 mm measured by endoscopic ultrasound (EUS).

METHODS

This retrospective cohort study included consecutive patients with small gastric SELs < 20 mm diagnosed using EUS at a tertiary referral center between 2009 and 2021. The clinical course after diagnosis using EUS-guided fine-needle aspiration (EUS-FNA) was reviewed.

RESULTS

Among 333 patients with small gastric SELs, 104 patients with 105 lesions underwent EUS-FNA. The pathological diagnosis was confirmed in 87 patients. GISTs were the most common pathology (47%). Among the 87 patients, 43 underwent therapeutic interventions, including tumor resection and chemotherapy. In groups of tumor resection, the pathological tumor size on the resected specimen was significantly larger than the size measured by EUS (19.5 mm vs 15.0 mm, P < 0.001), and 37% of resected SELs were 20 mm or over. No recurrence was observed after tumor resection during a mean follow-up period of 40 months.

CONCLUSIONS

Approximately 40% of small gastric SELs were malignant tumors, such as GIST, with most of them requiring treatment. Additionally, considering that the EUS measurement is 5 mm smaller than the pathological tumor diameter, further examinations, such as systematic EUS-FNA, may be required for SEL, including those smaller than 20 mm.

The impact of gender on survival outcomes in patients with small intestinal stromal tumors: a comprehensive analysis using the SEER database

BACKGROUND

Small intestinal stromal tumors (SISTs) are a rare type of mesenchymal tumor. Gender is known to influence the incidence and prognosis of various tumors, but its role on the survival of SISTs at the population level remains unclear. Therefore, we aim to explore the relationship between gender and the prognosis of SISTs using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Data on SISTs patients from 2000 to 2019 were derived from the SEER database. Multiple imputation was used to address missing data. Kaplan-Meier analyses and Cox proportional hazard models were applied to evaluate the impact of demographic and clinical characteristics on overall survival (OS) and cancer-specific survival (CSS).

RESULTS

A total of 3513 patients with SISTs were analyzed, including 1921 males and 1592 females. Kaplan-Meier analysis coupled with log-rank testing demonstrated a significantly higher mortality rate among male patients compared to females (P < 0.001). Notably, female patients exhibited superior OS (hazard ratio [HR] 0.808, 95% confidence interval [CI] 0.724-0.902, P < 0.001) and CSS (HR 0.801, 95% CI 0.692-0.927, P = 0.003) compared to male patients. While the mean 1-year CSS rates were comparable between genders (95.3% for males vs. 96.0% for females, P = 0.332), male patients consistently showed lower mean survival rates at 3-, 5-, and 10-year intervals. Surgical intervention significantly boosted 5-year OS and CSS rates in both male and female patients (P < 0.001). Multivariate Cox regression analysis identified age, sex, grade, TNM stage, surgery, and mitotic rate as independent risk factors for OS and CSS in patients with SISTs.

CONCLUSIONS

Our findings suggest that male patients with SISTs have a higher risk of mortality compared to female patients, indicating that gender may serve as a predictive indicator for survival in this patient population.

Endoscopic full-thickness resection for gastric submucosal tumors: Japanese multicenter prospective study

OBJECTIVES

Early gastric cancer endoscopic resection (ER) is prominent in Japan. However, evidence regarding ER of gastric submucosal tumors (SMT) is limited. This prospective multicenter phase II study investigated the efficacy and safety of endoscopic full-thickness resection (EFTR) for gastric SMT.

METHODS

Endoscopic full-thickness resection indication for gastric SMT was 11-30 mm, histologically proven or clinically suspicious (irregular margin, increasing size, or internal heterogeneity) gastrointestinal stromal tumors (GIST), with no ulceration and intraluminal growth type. The primary end-point was the complete ER (ER0) rate, with a sample size of 42.

RESULTS

We enrolled 46 patients with 46 lesions between September 2020 and May 2023 at seven Japanese institutions. The mean ± SD (range) endoscopic tumor size was 18.8 ± 4.5 (11-28) mm. The tumor resection and defect closure times were 54 ± 26 (22-125) min and 33 ± 28 (12-186) min, respectively. A 100% ER0 was achieved in all 46 patients. The EFTR procedure was accomplished in all patients without surgical intervention. One patient had delayed perforation and was managed endoscopically. GIST accounted for 76% (n = 35) of the cases. R0, R1, and RX rates were 33 (77%), 3 (6.5%), and 7 (15%), respectively.

CONCLUSION

Endoscopic full-thickness resection for gastric SMT of 11-30 mm is efficacious. It warrants further validation in a large-scale cohort study to determine the long-term outcome of this treatment for patients with gastric GIST.

English version of Japanese Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) issued by the Japan Society of Clinical Oncology

The Japan Society of Clinical Oncology Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) have been published in accordance with the Minds Manual for Guideline Development 2014 and 2017. A specialized team independent of the working group for the revision performed a systematic review. Since GIST is a rare type of tumor, clinical evidence is not sufficient to answer several clinical and background questions. Thus, in these guidelines, we considered that consensus among the experts who manage GIST, the balance between benefits and harms, patients' wishes, medical economic perspective, etc. are important considerations in addition to the evidence. Although guidelines for the treatment of GIST have also been published by the National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO), there are some differences between the treatments proposed in those guidelines and the treatments in the present guidelines because of the differences in health insurance systems among countries.

Comparative Analysis of Enbloc or Piecemeal Removal After Enbloc Resection of Gastrointestinal Stromal Tumors

OBJECTIVE

To investigate the safety and prognosis of enbloc or piecemeal removal after enbloc resection of a gastric GIST by comparing the clinical data of endoscopic en block resection and piecemeal removal (EP) and en block resection and complete removal (EC) of gastric GISTs.

METHODS

A total of 111 (43 endoscopic piecemeal, and 68 complete removal) patients with gastric GIST's ≥ 2 cm in diameter who underwent endoscopic therapy from January 2016 to June 2020 at the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. In all cases, it was ensured that the tumor was intact during the resection, however, it was divided into EP group and EC group based on whether the tumor was completely removed or was cut into pieces which were then removed. The patients' recurrence-free survival rate and recurrence-free survival (RFS) were recorded.

RESULTS

There was no statistically significant difference in RFS rates between the two groups (P = 0.197). The EP group had relatively high patient age, tumor diameter, risk classification, and operation time. However, there was no statistically significant difference in the number of nuclear fission images, postoperative hospitalization time, postoperative fasting time, complication rate and complication grading between the two groups (P > 0.05).

CONCLUSION

Endoscopic piecemeal removal after en block resection of gastric GIST is safe and effective and achieves similar clinical outcomes as complete removal after en block resection.

Automatically optimized radiomics modeling system for small gastric submucosal tumor (<2 cm) discrimination based on EUS images

BACKGROUND AND AIMS

The clinical management of small gastric submucosal tumors (SMTs) (<2 cm) faces a non-negligible challenge because of the lack of guideline consensus and effective diagnostic tools. This article develops an automatically optimized radiomics modeling system (AORMS) based on EUS images to diagnose and evaluate SMTs.

METHODS

A total of 205 patients with EUS images of small gastric SMTs (<2 cm) were retrospectively enrolled in the development phase of AORMS for the diagnosis and the risk stratification of GI stromal tumor (GIST). A total of 178 patients with images from different centers were prospectively enrolled in the independent testing phase. The performance of AORMS was compared to that of endoscopists in the development set and evaluated in the independent testing set.

RESULTS

AORMS demonstrated an area under the curve (AUC) of 0.762 for the diagnosis of GIST and 0.734 for the risk stratification of GIST, respectively. In the independent testing set, AORMS achieved an AUC of 0.770 and 0.750 for the diagnosis and risk stratification of small GISTs, respectively. In comparison, the AUCs of 5 experienced endoscopists ranged from 0.501 to 0.608 for diagnosing GIST and from 0.562 to 0.748 for risk stratification. AORMS outperformed experienced endoscopists by more than 20% in diagnosing GIST.

CONCLUSIONS

AORMS implements automatic parameter selection, which enhances its robustness and clinical applicability. It has demonstrated good performance in the diagnosis and risk stratification of GISTs, which could aid endoscopists in the diagnosis of small gastric SMTs (<2 cm).

MicroRNA-128 acts as a suppressor in the progression of gastrointestinal stromal tumor by targeting B-lymphoma Mo-MLV insertion region 1

INTRODUCTION

The critical role of microRNA-128 (miR-128) in gastrointestinal-related diseases has been documented. In the current study, we tried to clarify the specific role miR-128 in gastrointestinal stromal tumor (GIST) and the underlying mechanism.

METHODS

Differentially expressed genes in GIST were identified following bioinformatics analysis. Then, expression patterns of miR-128 and B-lymphoma Mo-MLV insertion region 1 (BMI-1) in clinical tissue samples and cell lines were characterized, followed by validation of their correlation. GIST-T1 cells were selected and transfected with different mimic, inhibitor, or siRNA plasmids, after which the biological functions were assayed.

RESULTS

We identified low miR-128 and high BMI-1 expression in GIST tissues of 78 patients and 4 GIST cell lines. Ectopic expression of miR-128 or silencing of BMI-1 suppressed the malignant potentials of GIST-T1 cells. As a target of miR-128, BMI-1 re-expression could partly counteract the suppressive effect of miR-128 on the malignancy of GIST-T1 cells.

CONCLUSION

Our study provided evidence that miR-128-mediated silencing of BMI-1 could prevent malignant progression of GIST, highlighting a promising anti-tumor target for combating GIST.

Small gastric synovial sarcoma diagnosed and treatment by laparoscopic-endoscopic cooperative surgery: a case report

We report a case of small gastric synovial sarcoma (SS) finally diagnosed after laparoscopic-endoscopic cooperative surgery (LECS). A 50 year-old male underwent medical examination for a chief complaint of epigastric pain. Endoscopic examination showed a 20 mm submucosal tumor (SMT) located in the anterior wall which extended to the lesser curvature of the middle stomach. The biopsy tissue did not yield a definitive diagnosis. During 6 months of follow-up for this lesion suspected to be an inflammatory tumor, neither the shape nor the size of the tumor changed. We performed LECS for both diagnosis and treatment. Histologically, the tumor was composed of fascicles of spindle cells. Immunohistochemically, the tumor cells were focally positive for epithelial membrane antigen, cytokeratin (AE1/AE3) and S100 protein, while being negative for desmin, α-smooth muscle actin, CD34, c-kit and DOG1. The expression of INI1 was reduced. Fluorescence in situ hybridization (FISH) detected SS18 rearrangement. The SMT was diagnosed as primary SS. A SMT measuring < 20 mm might be malignant potential tumor such as SS even if there are no typical malignant findings by endoscopy. Surgical resection should be considered for SMT measuring < 20 mm with atypical findings even in the absence of definitive high-risk features.

EZH2 as a potential therapeutic target for gastrointestinal cancers

Gastrointestinal (GI) cancers continue to be a major cause of mortality and morbidity globally. Understanding the molecular pathways associated with cancer progression and severity is essential for creating effective cancer treatments. In cancer research, there is a notable emphasis on Enhancer of zeste homolog 2 (EZH2), a key player in gene expression influenced by its irregular expression and capacity to attach to promoters and alter methylation status. This review explores the impact of EZH2 signaling on various GI cancers, such as colorectal, gastric, pancreatic, hepatocellular, esophageal, and cholangiocarcinoma. The primary function of EZH2 signaling is to facilitate the accelerated progression of cancer cells. Additionally, EZH2 has the capacity to modulate the reaction of GI cancers to chemotherapy and radiotherapy. Numerous pathways, including long non-coding RNAs and microRNAs, serve as upstream regulators of EZH2 in these types of cancer. EZH2's enzymatic activity enables it to attach to target gene promoters, resulting in methylation that modifies their expression. EZH2 could be considered as an independent prognostic factor, with increased expression correlating with a worse disease prognosis. Additionally, a range of gene therapies including small interfering RNA, and anti-tumor agents are being explored to target EZH2 for cancer treatment. This comprehensive review underscores the current insights into EZH2 signaling in gastrointestinal cancers and examines the prospect of therapies targeting EZH2 to enhance patient outcomes.

Possibility of Using Conventional Computed Tomography Features and Histogram Texture Analysis Parameters as Imaging Biomarkers for Preoperative Prediction of High-Risk Gastrointestinal Stromal Tumors of the Stomach

BACKGROUND

The objective of this study is to determine the morphological computed tomography features of the tumor and texture analysis parameters, which may be a useful diagnostic tool for the preoperative prediction of high-risk gastrointestinal stromal tumors (HR GISTs).

METHODS

This is a prospective cohort study that was carried out in the period from 2019 to 2022. The study included 79 patients who underwent CT examination, texture analysis, surgical resection of a lesion that was suspicious for GIST as well as pathohistological and immunohistochemical analysis.

RESULTS

Textural analysis pointed out min norm (p = 0.032) as a histogram parameter that significantly differed between HR and LR GISTs, while min norm (p = 0.007), skewness (p = 0.035) and kurtosis (p = 0.003) showed significant differences between high-grade and low-grade tumors. Univariate regression analysis identified tumor diameter, margin appearance, growth pattern, lesion shape, structure, mucosal continuity, enlarged peri- and intra-tumoral feeding or draining vessel (EFDV) and max norm as significant predictive factors for HR GISTs. Interrupted mucosa (p < 0.001) and presence of EFDV (p < 0.001) were obtained by multivariate regression analysis as independent predictive factors of high-risk GISTs with an AUC of 0.878 (CI: 0.797-0.959), sensitivity of 94%, specificity of 77% and accuracy of 88%.

CONCLUSION

This result shows that morphological CT features of GIST are of great importance in the prediction of non-invasive preoperative metastatic risk. The incorporation of texture analysis into basic imaging protocols may further improve the preoperative assessment of risk stratification.

Hallmarks and novel insights for gastrointestinal stromal tumors: A bibliometric analysis

BACKGROUND

Due to the increasing recognition of gastrointestinal stromal tumor (GIST), novel insights have appeared in both preclinical and clinical research and begun to reshape the field. This study aims to map the research landscape through bibliometric analysis and provide a brief overview for the future of the GIST field.

METHODS

We searched the Web of Science Core Collection without publication data restrictions for GISTs and performed a bibliometric analysis with CiteSpace and VOSviewer software.

RESULTS

In sum, 5,911 of 13,776 records were included, and these studies were published in 948 journals and written by 24,965 authors from 4,633 institutions in 100 countries. Referring to published reviews and bibliometric analysis, we classified the future trends in four groups. In epidemiological study, precise incidence and clinicopathological features in different regions and races might become potential hotspots. Novel therapy, such as drugs, modified strategies, radioligand therapy, was persistent hotspots in GIST fields, and ctDNA-guided diagnosis, monitoring, and treatment might meet future clinical needs. The debate over serosa surgery vs. mucosa surgery will remain active for a long time in GIST surgery, and function reserve surgery, biology-based surgery will play an important role in future. Moreover, rare GIST type, like NF-1-associated GIST, Carney triads and SDH mutant GIST, need more studies in pathogenesis and genetic mutation to provide appropriate treatment for this orphan GIST patients.

CONCLUSIONS

Potential hotspots in future GIST trends might involve epidemiology, agents, resection therapy and rare type GIST, moreover, researchers could pay more attention in these four fields.

Esterase-Responsive Polyglycerol-Based Nanogels for Intracellular Drug Delivery in Rare Gastrointestinal Stromal Tumors

Rare gastrointestinal stromal tumors (GISTs) are caused by mutations in the KIT and PDGFRA genes. Avapritinib (BLU-285) is a targeted selective inhibitor for mutated KIT and PDGFRA receptors that can be used to treat these tumors. However, there are subtypes of GISTs that exhibit resistance against BLU-285 and thus require other treatment strategies. This can be addressed by employing a drug delivery system that transports a combination of drugs with distinct cell targets. In this work, we present the synthesis of esterase-responsive polyglycerol-based nanogels (NGs) to overcome drug resistance in rare GISTs. Using inverse nanoprecipitation mediated with inverse electron-demand Diels-Alder cyclizations (iEDDA) between dPG-methyl tetrazine and dPG-norbornene, multi-drug-loaded NGs were formed based on a surfactant-free encapsulation protocol. The obtained NGs displayed great stability in the presence of fetal bovine serum (FBS) and did not trigger hemolysis in red blood cells over a period of 24 h. Exposing the NGs to Candida Antarctica Lipase B (CALB) led to the degradation of the NG network, indicating the capability of targeted drug release. The bioactivity of the loaded NGs was tested in vitro on various cell lines of the GIST-T1 family, which exhibit different drug resistances. Cell internalization with comparable uptake kinetics of the NGs could be confirmed by confocal laser scanning microscopy (CLSM) and flow cytometry for all cell lines. Cell viability and live cell imaging studies revealed that the loaded NGs are capable of intracellular drug release by showing similar IC50 values to those of the free drugs. Furthermore, multi-drug-loaded NGs were capable of overcoming BLU-285 resistance in T1-α-D842V + G680R cells, demonstrating the utility of this carrier system.

Survival analysis of extragastrointestinal stromal tumors based on the SEER database: a population-based study

BACKGROUND

Extragastrointestinal stromal tumors (EGISTs) are rare mesenchymal neoplasms that originate outside the gastrointestinal tract. However, the population-level survival analysis of EGIST remains poorly grasped. Therefore, we aimed to analyze the survival of EGIST patients using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

All patients diagnosed with GIST and EGIST between 2000 and 2019 were identified through utilization of the SEER database. Missing data were handled using multiple imputation methodology. Kaplan-Meier analyses and Cox proportional hazard models were employed to assess the influence of demographic and clinical characteristics on both overall survival (OS) and cancer-specific survival (CSS).

RESULTS

A total of 13,330 patients were enrolled in the study, comprising 12,627 diagnosed with GIST and 703 with EGIST. EGIST patients demonstrated significantly poorer OS [hazard ratio (HR) 1.732, 95% confidence interval (CI) 1.522-1.970, P < 0.001] and CSS (HR 2.167, 95% CI 1.821-2.577, P < 0.001) compared to GIST patients. The mean 1-year, 3-year, 5-year, and 10-year OS rates for EGIST patients were 78.3%, 61.9%, 50.5%, and 32.5%, respectively, with corresponding mean CSS rates of 84.3%, 70.8%, 61.3%, and 46.5%. Multivariate Cox regression analysis identified age, race, sex, grade, size, and surgical type as independent risk factors for OS in EGIST patients, while age, sex, year of diagnosis, grade, surgical type, and radiation therapy were identified as independent risk factors for CSS. Patients with EGIST who underwent surgical treatment exhibited significantly higher 5-year OS rates (49.0% vs. 39.9%, P = 0.035) and CSS rates (63.9% vs. 53.0%, P = 0.028) compared to those who did not undergo surgery.

CONCLUSIONS

EGIST patients have a poorer prognosis compared to GIST patients; however, surgical treatment has been shown to improve the prognosis.

Intelligent identification system of gastric stromal tumors based on blood biopsy indicators

BACKGROUND

The most prevalent mesenchymal-derived gastrointestinal cancers are gastric stromal tumors (GSTs), which have the highest incidence (60-70%) of all gastrointestinal stromal tumors (GISTs). However, simple and effective diagnostic and screening methods for GST remain a great challenge at home and abroad. This study aimed to build a GST early warning system based on a combination of machine learning algorithms and routine blood, biochemical and tumour marker indicators.

METHODS

In total, 697 complete samples were collected from four hospitals in Gansu Province, including 42 blood indicators from 318 pretreatment GST patients, 180 samples of gastric polyps and 199 healthy individuals. In this study, three algorithms, gradient boosting machine (GBM), random forest (RF), and logistic regression (LR), were chosen to build GST prediction models for comparison. The performance and stability of the models were evaluated using two different validation techniques: 5-fold cross-validation and external validation. The DeLong test assesses significant differences in AUC values by comparing different ROC curves, the variance and covariance of the AUC value.

RESULTS

The AUC values of both the GBM and RF models were higher than those of the LR model, and this difference was statistically significant (P < 0.05). The GBM model was considered to be the optimal model, as a larger area was enclosed by the ROC curve, and the axes indicated robust model classification performance according to the accepted model discriminant. Finally, the integration of 8 top-ranked blood indices was proven to be able to distinguish GST from gastric polyps and healthy people with sensitivity, specificity and area under the curve of 0.941, 0.807 and 0.951 for the cross-validation set, respectively.

CONCLUSION

The GBM demonstrated powerful classification performance and was able to rapidly distinguish GST patients from gastric polyps and healthy individuals. This identification system not only provides an innovative strategy for the diagnosis of GST but also enables the exploration of hidden associations between blood parameters and GST for subsequent studies on the prevention and disease surveillance management of GST. The GST discrimination system is available online for free testing of doctors and high-risk groups at https://jzlyc.gsyy.cn/bear/mobile/index.html .

Impact of Tumor Size and Management on Survival in Small Gastric Gastrointestinal Stromal Tumors

BACKGROUND

Society guidelines remain inconsistent on the role of endoscopic and radiographic surveillance as an alternative to surgical resection of small gastric gastrointestinal stromal tumors (GISTs). Herein, we aimed to assess survival among patients with gastric GISTs undergoing observation versus surgical resection, stratified by tumor size.

METHODS

The National Cancer Database (NCDB) was queried for gastric GISTs < 2 cm diagnosed from 2010-2017. Patients were stratified by management strategy-observation vs surgical resection. The primary outcome, overall survival (OS), was examined with Kaplan-Meier and multivariable Cox proportional hazard methods. Subgroup analyses were conducted on tumors < 1 cm and 1-2 cm in size.

RESULTS

Altogether, 1208 patients were identified: 439 (36.3%) undergoing observation and 769 (63.7%) receiving surgical resection. In the overall cohort, patients undergoing surgical resection demonstrated improved survival (93.6 vs. 88.8% 5-year OS, p=0.02). In multivariable analysis, upfront surgical resection was not associated with a reduction in mortality; however, there was a significant interaction with tumor size. For patients with tumors < 1 cm, there was no difference in survival based on management strategy. However, resection of tumors 1-2 cm was associated with improved survival relative to surveillance.

CONCLUSIONS

While surgical resection and surveillance were associated with similar survival for patients with gastric GISTs < 1 cm, this NCDB analysis suggests that patients with tumor size ≥ 1 cm may benefit from upfront surgical resection. Prospective studies comparing these two approaches and their impact on recurrence-free and disease-specific survival are needed to better align consensus guidelines and recommendations.

Endoscopic Resection with One-Port Placement: A Newly Developed Technique for the Safe Management of Advanced Endoscopic Resection for Gastric Gastrointestinal Stromal Tumors

INTRODUCTION

Endoscopic full-thickness resection (EFTR) without laparoscopic assistance (pure EFTR) is an emerging, less invasive treatment for gastrointestinal stromal tumors (GISTs). However, the technique has seldom been performed outside China because of concerns regarding pneumoperitoneum, maintenance of endoscopic view, and endoscopic suturing. This study aimed to evaluate the efficacy and safety of endoscopic resection with one-port placement (EROPP) for gastric GISTs.

METHODS

This retrospective study included 17 patients with gastric GISTs originating from the muscularis propria who underwent EROPP between 2019 and 2022. One camera port was inserted in the umbilicus before initiating the endoscopic procedure to maintain intra-abdominal pressure, which was monitored and adjusted via this port. While allowing for conversion to laparoscopic surgery if needed, EFTR was performed as follows: (1) circumferential incision of the mucosal and submucosal layers around the lesion was performed by typical endoscopic submucosal dissection; (2) an intentional perforation and subsequent seromuscular resection was made using dental floss and an endo-clip for traction; and (3) closure of the gastric full-thickness defect was performed with an over-the-scope clip (OTSC) after peroral retrieval of the specimen. We retrospectively assessed the short-term outcomes and safety.

RESULTS

All procedures were completed successfully without conversion to laparoscopic surgery. The median size of the resected tumors was 23 mm (range, 8-35 mm), the median resection time was 36 min (range, 22-95 min), and closure time was 18 min (range, 10-45 min). The rates of en bloc and complete resection were 100% and 88%, respectively. In 2 cases, another port was added to aspirate the leaking fluid or check the condition of the endoscopic closure. All gastric defects were endoscopically closed, mainly using OTSCs. The recovery course for all patients was uneventful, and no adverse events were reported.

CONCLUSIONS

EROPP is a safe and minimally invasive treatment for gastric GISTs and appears to be suitable for introducing EFTR procedures.

Incidence Trends and Main Features of Gastro-Intestinal Stromal Tumours in a Mediterranean Region: A Population-Based Study

Gastro-Intestinal Stromal Tumours (GISTs) are a kind of neoplasm whose diagnosis in common clinical practice just started in the current century, implying difficulties for proper registration. Staff from the Cancer Registry of Murcia, in southeastern Spain, were commissioned by the EU Joint Action on Rare Cancers into a pilot study addressing GIST registration that also yielded a population-based depiction of GISTs in the region, including survival figures. We examined reports from 2001 to 2015 from hospitals as well as cases already present in the registry. The variables collected were sex, date of diagnosis, age, vital status, primary location, presence of metastases, and risk level according to Joensuu's Classification. In total, 171 cases were found, 54.4% occurred in males, and the mean age value was 65.0 years. The most affected organ was the stomach, with 52.6% of cases. Risk level was determined as "High" for 45.0%, with an increment of lower levels in recent years. Incidence for the year 2015 doubled that of 2001. Overall, the 5-year net survival estimation was 77.0%. The rising incidence magnitude is consistent with trends in other European countries. Survival evolution lacked statistical significance. A more interventional approach in clinical management could explain the increase in the proportion of "Low Risk GISTs" and the first occurrence of "Very Low Risk" in recent years.

Risk stratification for 1- to 2-cm gastric gastrointestinal stromal tumors: visual assessment of CT and EUS high-risk features versus CT radiomics analysis

OBJECTIVES

To investigate the ability of CT and endoscopic sonography (EUS) in predicting the malignant risk of 1-2-cm gastric gastrointestinal stromal tumors (gGISTs) and to clarify whether radiomics could be applied for risk stratification.

METHODS

A total of 151 pathologically confirmed 1-2-cm gGISTs from seven institutions were identified by contrast-enhanced CT scans between January 2010 and March 2021. A detailed description of EUS morphological features was available for 73 gGISTs. The association between EUS or CT high-risk features and pathological malignant potential was evaluated. gGISTs were randomly divided into three groups to build the radiomics model, including 74 in the training cohort, 37 in validation cohort, and 40 in testing cohort. The ROIs covering the whole tumor volume were delineated on the CT images of the portal venous phase. The Pearson test and least absolute shrinkage and selection operator (LASSO) algorithm were used for feature selection, and the ROC curves were used to evaluate the model performance.

RESULTS

The presence of EUS- and CT-based morphological high-risk features, including calcification, necrosis, intratumoral heterogeneity, irregular border, or surface ulceration, did not differ between very-low and intermediate risk 1-2-cm gGISTs (p > 0.05). The radiomics model consisting of five radiomics features showed favorable performance in discrimination of malignant 1-2-cm gGISTs, with the AUC of the training, validation, and testing cohort as 0.866, 0.812, and 0.766, respectively.

CONCLUSIONS

Instead of CT- and EUS-based morphological high-risk features, the CT radiomics model could potentially be applied for preoperative risk stratification of 1-2-cm gGISTs.

KEY POINTS

• The presence of EUS- and CT-based morphological high-risk factors, including calcification, necrosis, intratumoral heterogeneity, irregular border, or surface ulceration, did not correlate with the pathological malignant potential of 1-2-cm gGISTs. • The CT radiomics model could potentially be applied for preoperative risk stratification of 1-2-cm gGISTs.

Endoscopic full‑thickness resection with clip‑ and snare‑assisted traction for gastric submucosal tumours in the fundus: A single‑centre case series

Exposed endoscopic full-thickness resection (Eo-EFTR) has been recognized as a feasible therapy for gastrointestinal submucosal tumours (SMTs) originating deep in the muscularis propria layer; however, Eo-EFTR is difficult to perform in a retroflexed fashion in the gastric fundus. As a supportive technique, clip- and snare-assisted traction may help expose the surgical field and shorten the operation time in endoscopic resection of difficult regions. However, the application of clip- and snare-assisted traction in Eo-EFTR of SMTs in the gastric fundus is limited. Between April 2018 and December 2021, Eo-EFTR with clip- and snare-assisted traction was performed in 20 patients with SMTs in the gastric fundus at The First Affiliated Hospital of Soochow University. The relevant clinical data were collected retrospectively for all of the patients and analysed. All 20 patients underwent Eo-EFTR successfully without conversion to open surgery or severe adverse events. The en bloc resection rate and R0 resection rate were both 100%. Two patients had abdominal pain and fever after the operation, and five patients had fever, which recovered with medical therapy. No complications, such as delayed bleeding or delayed perforation, were observed. The postoperative pathology indicated that 19 cases were gastrointestinal stromal tumours and one case was leiomyoma. During the follow-up, no residual tumour, local recurrence or distant metastasis was detected by endoscopy or abdominal computed tomography. In conclusion, Eo-EFTR with clip- and snare-assisted traction appears to be a relatively safe and effective treatment for gastric SMTs in the fundus. However, prospective studies on a larger sample size are required to verify the effect of the clip- and snare-assisted traction in Eo-EFTR.

Mucosal Ulceration in Gastrointestinal Stromal Tumor is an Independent Predictor of Progression-Free Survival

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. Known prognostic features of GISTs include tumor mitotic rate, size, and location, yet one common feature of primary GISTs for which prognostic significance is unknown, is mucosal ulceration. This study aims to investigate the significance of mucosal ulceration in GISTs.

MATERIALS AND METHODS

A retrospective study was conducted of 513 patients at a tertiary referral center with a suspected or documented diagnosis of primary GIST between the years of 2000 and 2020. Ulceration was confirmed by definitive documentation in the endoscopic or histopathologic report. The significance of ulceration in GIST was compared to other prognostic factors.

RESULTS

Of the 513 patients reviewed, 310 primary GIST patients with known ulceration and disease status were identified. Of those, 27.4% (n = 85) demonstrated mucosal ulceration. Mucosal ulceration in GISTs is associated with GI bleeding, mitotic rate, tumor size, and exon 11 mutations. After a median follow-up of 35.4 (interquartile range = 17.1-62.2) mo, patients with ulcerated GISTs experienced higher rates of tumor progression (40.0% versus 14.2%, P < 0.0001). In multivariate analysis, ulceration of GISTs was highly associated with disease progression (P < 0.0001) and progression-free survival (hazard ratio = 2.4 [1.2-4.7], P = 0.01).

CONCLUSIONS

Mucosal ulceration in GISTs is associated with GI bleeding, mitotic rate, tumor size, and exon 11 mutations. Overall, ulceration in GISTs is associated with elevated risk of tumor progression and is an independent prognostic factor. In multivariate analysis, ulceration in GIST remains an independent risk factor for disease progression.

LAPAROSCOPIC VERSUS OPEN SURGERY IN GASTRIC GASTROINTESTINAL STROMAL TUMORS LARGER THAN 5 CM: A SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

Surgical resection represents the main treatment for resectable nonmetastatic gastric gastrointestinal stromal tumors. Despite the feasibility and safety of laparoscopic resection, its standard use in gastric tumors larger than 5 cm is yet to be established.

AIMS

This study aimed to compare the current evidence on laparoscopic resection with the classical open surgical approach in terms of perioperative, postoperative, and oncological outcomes.

METHODS

The PubMed, Scopus, and Web of Science databases were consulted. Articles comparing the approach to gastric gastric gastrointestinal stromal tumors larger than 5 cm by open and laparoscopic surgery were eligible. A post hoc subgroup analysis based on the extent of the surgery was performed to evaluate the operative time, blood loss, and length of hospital stay.

RESULTS

A total of nine studies met the eligibility criteria. In the study, 246 patients undergoing laparoscopic surgery and 301 patients undergoing open surgery were included. The laparoscopic approach had statistically significant lower intraoperative blood loss (p=0.01) and time to oral intake (p<0.01), time to first flatus (p<0.01), and length of hospital stay (0.01), compared to the open surgery approach. No significant differences were found when operative time (0.25), postoperative complications (0.08), R0 resection (0.76), and recurrence rate (0.09) were evaluated. The comparative subgroup analysis between studies could not explain the substantial heterogeneity obtained in the respective outcomes.

CONCLUSION

The laparoscopic approach in gastric gastrointestinal stromal tumors larger than 5 cm compared to the open surgical approach is a technically safe and feasible surgical method with similar oncological results.

Case report: Giant cystic ileal gastrointestinal stromal tumor with an atypical intratumoral abscess

Background

Gastrointestinal stromal tumors (GISTs) are typically solid, sometimes with small cystic areas, but rarely manifest as predominantly cystic neoplasms. In addition, cystic intestinal GISTs with intratumoral abscess formation are rare.

Case presentation

We present the case of a 49-year-old male patient with a history of frequent and urgent urination for 2 weeks. Radiologic studies revealed a large cystic mass in the lower abdomen. The patient underwent abdominal laparotomy, which revealed a large cystic mass arising from the distal ileum invading the sigmoid mesocolon and apex vesicae. Partial resection of the ileum along with the tumor and the adjacent bladder was performed. Macroscopic examination revealed that the cystic mass contained a large amount of foul-smelling pus and a tumor-bowel fistula. The final pathology revealed an abdominal stromal tumor. Postoperative recovery was uneventful, and adjuvant imatinib mesylate 400 mg was administered daily. No tumor recurrence or metastasis was observed during the 9-month follow-up period.

Conclusion

Fingings of a cystic tumor in the abdomen should raise concern for cystic GISTs. This case report reviews a rare presentation of an ileal giant cystic GIST with atypical intratumoral abscess formation. Complete surgical resection and adjuvant imatinib is still the mainstay treatment for GISTs.

Gastric defect closure after endoscopic full-thickness resection: the closing while dissecting technique

BACKGROUND

Complete closure of gastric wall defects is critical following endoscopic full-thickness resection (EFTR). The aim of this study was to evaluate the efficacy, safety, and clinical outcome of a new endoscopic method: closing while dissecting.

METHODS

Twenty-seven patients who underwent EFTR were retrospectively analyzed between January 2020 and March 2021. Gastric defects resulting from EFTR were closed using the "interrupted-close during dissection" technique with endoclips. Tumor characteristics, en bloc resection rates, and postoperative adverse events were evaluated.

RESULTS

All submucosal tumors were successfully resected and complete resection was histologically confirmed. The mean maximal tumor diameter was 1.3 cm (ranging from 0.8 to 3.0 cm). The majority of these tumors were gastrointestinal stromal tumors (n = 20), Leiomyoma (n = 3), schwannomas (n = 2), others included fibroma (n = 1) and neurogenic tumor (n = 1). There were no cases of hemorrhage, peritonitis, or delayed perforation. Four patients complained of slight abdominal pain, but no hyperpyrexia or serious elevated white blood cell count was detected in the first 24 h after treatment. All wounds were healed on follow-up endoscopy 3 months after the procedure. The mean follow-up duration was 8.5 months (ranging from 3 to 17) and no tumor recurrences were observed.

CONCLUSIONS

The feasibility and safety of this interrupted-close during dissection approach allows for clinical applications in EFTR of gastric submucosal tumors.

Advances of endoscopic and surgical management in gastrointestinal stromal tumors

As one of the most common mesenchymal malignancies in the digestive system, gastrointestinal stromal tumors (GISTs) occur throughout the alimentary tract with diversified oncological characteristics. With the advent of the tyrosine kinase inhibitor era, the treatment regimens of patients with GISTs have been revolutionized and GISTs have become the paradigm of multidisciplinary therapy. However, surgery resection remains recognized as the potentially curative management for the radical resection and provided with favorable oncological outcomes. The existing available surgery algorithms in clinical practice primarily incorporate open procedure, and endoscopic and laparoscopic surgery together with combined operation techniques. The performance of various surgery methods often refers to the consideration of risk evaluation of recurrence and metastases; the degree of disease progression; size, location, and growth pattern of tumor; general conditions of selected patients; and indications and safety profile of various techniques. In the present review, we summarize the fundamental principle of surgery of GISTs based on risk assessment as well as tumor size, location, and degree of progress with an emphasis on the indications, strengths, and limitations of current surgery techniques.

Small Gastric Stromal Tumors: An Underestimated Risk

BACKGROUND AND OBJECTIVES

Small gastrointestinal stromal tumors (GISTs) are defined as tumors less than 2 cm in diameter, which are often found incidentally during gastroscopy. There is controversy regarding the management of small GISTs, and a certain percentage of small GISTs become malignant during follow-up. Previous studies which used Sanger targeted sequencing have shown that the mutation rate of small GISTs is significantly lower than that of large tumors. The aim of this study was to investigate the overall mutational profile of small GISTs, including those of wild-type tumors, using whole-exome sequencing (WES) and Sanger sequencing.

METHODS

Thirty-six paired small GIST specimens, which were resected by endoscopy, were analyzed by WES. Somatic mutations identified by WES were confirmed by Sanger sequencing. Sanger sequencing was performed in an additional 38 small gastric stromal tumor samples for examining hotspot mutations in KIT, PDGFRA, and BRAF.

RESULTS

Somatic C-KIT/PDGFRA mutations accounted for 81% of the mutations, including three novel mutation sites in C-KIT at exon 11, across the entire small gastric stromal tumor cohort (n = 74). In addition, 15% of small GISTs harbored previously undescribed BRAF-V600E hotspot mutations. No significant correlation was observed among the genotype, pathological features, and clinical classification.

CONCLUSIONS

Our data revealed a high overall mutation rate (~96%) in small GISTs, indicating that genetic alterations are common events in early GIST generation. We also identified a high frequency of oncogenic BRAF-V600E mutations (15%) in small GISTs, which has not been previously reported.

Efficacy and feasibility of snare-assisted endoscopic resection of small submucosal gastric tumors: A retrospective analysis

Background and aim

The prevalence of small submucosal gastric tumors is rising. Despite the fact that high success rate of endoscopic resection of small submucosal gastric tumors originating from the muscularis propria has been reported, the procedure is technically challenging and has a high rate of complications. In this study, we investigated the efficacy and feasibility of a novel snare-assisted endoscopic resection technique for small submucosal gastric tumors.

Patients and methods

This is a single-center consecutive study of 50 patients who were diagnosed with small submucosal gastric tumors originating from the muscularis propria and who subsequently underwent snare-assisted endoscopic resection between January 2019 and January 2021 at our hospital. Data on the demographic characteristics, procedural success rate, complications, recurrence rate, and histopathology of the resected specimen were collected and analyzed retrospectively.

Results

The majority of the patient’s population was male (66%) with the mean age of 48.4 ± 9 years (range, 20–70 years). The mean size of the tumor confirmed by endoscopic ultrasonography was 6.4 ± 1.6 mm (range, 3.1–9.8 mm). All the tumors were resected successfully using snare-assisted endoscopic resection technique. The mean procedure time was 22.8 ± 9.6 (range, 15–35 min). The technical (performed the procedure successfully without converting to surgery) and clinical (the patient fully recovered after the procedure without experiencing any complications) success rate of the procedure was 100%. Eighteen (24%) patients had very small amount of mucosal damage, and wound closure was not needed in these patients. During 6–24 months of follow-up, no recurrence or metastasis occurred. No adverse event was noted during the follow-up time.

Conclusion

The novel approach of snare-assisted endoscopic resection is simple, feasible, and effective for tumors with small size and originating from the gastric muscularis propria. In addition, it offers a better alternative therapy for the complete resection of small submucosal gastric tumors. Its advantages compared with traditional endoscopic approaches such as endoscopic submucosal resection and endoscopic submucosal dissection include shorter procedure times, lesser cost, and a lower rate of complications (perforation, bleeding, and infection).

A propensity score-matched analysis of laparoscopic versus open surgical radical resection for gastric gastrointestinal stromal tumor

Background

Surgery is the mainstay of treatment for gastric gastrointestinal stromal tumours (GIST). However, the choice of surgical approach for gastric GIST remains controversial.

Aims and Objectives

To evaluate the short- and long-term efficacies of laparoscopic surgery versus conventional open surgery for gastric GIST.

Materials and Methods

We retrospectively reviewed 148 patients with gastric GIST at our hospital between January 2013 and January 2020. The patients were categorised into the following two groups based on the surgery performed: The laparoscopic surgery group (LG) and the open surgery group (OG). Differences in the tumour size, surgical procedures and modified National Institutes of Health classification were statistically significant. To balance the intergroup confounders, we performed 1:1 propensity score matching (PSM).

Results

A total of 104 patients were selected after PSM (52 in each group). We focused on the short- and long- term outcomes of patients. The baseline information was balanced between the two groups after PSM. The LG benefited from the advantages of a minimally invasive surgery (faster gastrointestinal function recovery, shorter time to drainage tube removal, less blood loss and shorter hospitalisation period), however, it also had high treatment costs. Moreover, both laparoscopic and open surgeries resulted in similar intra-operative and post-operative complications rates, overall survival time and disease-free survival time.

Conclusion

Laparoscopic resection is feasible and oncologically safe for GIST. However, more prospective studies are required to confirm the findings.

Advances in endoscopic resection techniques of small gastric tumors originating from the muscularis propria

Gastrointestinal stromal tumors are common gastrointestinal tumors typically originating from the muscularis propria layer of the stomach. Small gastric stromal tumors are usually detected incidentally during routine endoscopic examination. Although they may have malignant potentially, controversies remain regarding the need for endoscopic resection of small gastric stromal tumors originating from the muscularis propria. According to the guidelines of the European Society of Medical Oncology, all gastrointestinal stromal tumors >2 cm in size should be resected with endoscopic surveillance recommended for tumors <2 cm. Endoscopic resection including endoscopic mucosal dissection (EMD), endoscopic submucosal dissection (ESD), submucosal tunneling endoscopic resection and snare assisted endoscopic resection. However, EMD and ESD procedures may be accompanied with serious complications including perforation, bleeding, and abdominal infection. Snare-assisted endoscopic resection is an alternative approach and has the advantages of a shorter procedure time and a low rate of perforation or bleeding. This study summarizes the safety and feasibility of a novel snare-assisted endoscopic resection technique and highlights the pros and cons of the different endoscopic approaches currently used for subepithelia small gastric tumors.

Gastrointestinal Stromal Tumors and the General Surgeon

Gastrointestinal stromal tumors (GISTs) are rare malignancies of the gastrointestinal tract but are the most common sarcoma. This review covers aspects of the care of patients with GIST relevant to surgeons. In particular, management of sub-2 cm GISTs, the utility of neoadjuvant and adjuvant therapy for primary GISTs, and indications for surgery in the setting of metastatic disease are discussed.

Comparison of effectiveness and safety between endoscopic and surgical resection for 2-5 cm gastric stromal tumors

BACKGROUND

As endoscopic resection remains controversial, this study aims to compare the effectiveness and safety between endoscopic and surgical resection for 2-5 cm gastric stromal tumors (GSTs).

METHODS

Patients with 2-5 cm GST resected at West China Hospital from March 2008 to April 2019 were enrolled. Propensity score matching (PSM) (1:1) was performed to achieve baseline data consistency.

RESULTS

112 patients were matched between the endoscopic resection group (ER) and the open surgery group. There were no significant differences in the complete resection rate (94.6% vs. 100%), the incidence of complications (25.0% vs. 14.3%), the recurrence rate (0% vs. 1.8%) and the 5-year relapse-free survival (100% vs. 97.9%) (P > 0.05). The ER had a shorter fasting time (3.5 days vs. 5 days), a shorter postoperative hospital stay (7 days vs. 8 days) and a lower hospitalization cost (3,589.16 USD vs. 5,931.24 USD) (P < 0.05). 54 cases were matched between the ER and the laparoscopic surgery group (LS). There were no significant differences in the complete resection rate (92.6% vs. 96.3%), the incidence of complications (22.2% vs. 11.1%), the fasting time (4 days vs. 3 days), the recurrence rate (0% vs. 3.7%) and the 5-year relapse-free survival (100% vs. 96.3%) (P > 0.05). The hospitalization cost (3,589.25 USD vs. 4,715.16 USD) was lower in the ER, and the postoperative hospital stay was shorter in the LS (6 days vs. 7 days) (P < 0.05).

CONCLUSIONS

Although slightly higher incidences of incomplete resection and perforation were shown in the endoscopic resection group, there was insignificant difference between groups (P > 0.05). Endoscopic resection might be an alternative surgical method for 2-5 cm GSTs.

Gastrointestinal Stromal Tumor

Over the past 20 years, gastrointestinal stromal tumor (GIST) has evolved into an increasingly complex clinical entity with ever more challenges. While surgical resection is the gold standard, advancements in genetic testing, therapeutic options, immunotherapy, and management of metastatic disease necessitate a comprehensive, multimodal approach for these tumors. This chapter highlights the importance of genomic testing of GIST, the use of neoadjuvant and adjuvant therapy for localized disease, surgical principles for GIST, as well as current and new approaches for addressing metastatic disease.

Efficiency of an endoscopic resection strategy for management of submucosal tumors < 20 mm in the upper gastrointestinal tract

Background and study aims  The histologic diagnosis of submucosal tumors (SMTs) < 20 mm is challenging. Monitoring is the main option offered, but compliance is debatable. Endoscopic resection (ER) of malignant SMTs or those with an uncertain diagnosis is an alternative that has already been reported about and proposed in our center. The aims of this study were to confirm the safety of this resection strategy and to perform long-term follow-up of malignant SMTs after resection. Patients and methods  All patients who underwent ER for SMTs < 2 cm in a single center between 2007 and 2019 were included retrospectively. Patients were classified into two groups according to the need for postresection follow-up: benign SMTs (B-SMTs) and follow-up SMTs (FU-SMTs). Results  One hundred and one patients were included. The mean tumor size was 16.7 mm. In total, 92 of 101 SMTs had an uncertain diagnosis. Macroscopic resection was completed for 95 SMTs (93.1 %), with en bloc resection in 94 (92.1%). The morbidity rate was 3 %, with no mortality. A total of 84 of 101 SMTs (84 %) were B-SMTs and did not need monitoring, and 17 SMTs (19.7 %) were FU-SMTs (8 gastrointestinal stromal tumors, 6 neuroendocrine tumors, and 3 others). No relapse was reported in the FU-SMT group, with a median follow-up duration of 33 months [4-127] (61 months [17-127] for the gastrointestinal stroma tumor group). Conclusions  The study results suggest ER is a potentially reliable and effective strategy for upper gastrointestinal tract SMTs < 20 mm. Although the strategy needs further validation in advanced care units, it could eliminate the need for long-term monitoring, therefore targeting such follow-up efforts to patients with FU-SMTs.

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

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

Development and external validation of a nomogram for individualized adjuvant imatinib duration for high-risk gastrointestinal stromal tumors: A multicenter retrospective cohort study

Introduction

The main emphasis of the research about adjuvant imatinib for high‐risk gastrointestinal stromal tumors (GISTs) is prolonging the treatment duration and ignores the heterogeneous that 10‐year recurrence rates ranged from about 20%–100%. Thus, this study evaluated the effect of different durations of adjuvant imatinib on outcomes in high‐risk GISTs to explore the feasibility of individual treatment.

Methods

We analyzed 855 high‐risk GIST patients from three centers who underwent macroscopically complete resection between December 2007 and September 2020. The patients were divided into training (n =564) and two validation cohorts (n = 238 and53) based on their source. Recurrence‐free survival (RFS) was the primary point. Cox multivariate analysis was used to develop the nomogram. C‐index, time‐dependent area under the curves, and calibration plots were used to assess the performance of the nomogram.

Results

Univariate analysis showed that longer adjuvant imatinib was significantly associated with better 5‐year RFS (p < 0.0001). Further investigation identified that the same high‐risk patients with lower tumor‐associated recurrence risk benefitted little from prolonged treatment and that the recommended adjuvant imatinib duration was insufficient for those with higher recurrence risk. A nomogram for predicting 2‐, 3‐, and 5‐year RFS based on different treatment durations and four major risk factors, namely, tumor site, size, mitotic count, and rupture status, was built and validated, with a C‐index of 0.82, 0.74, and 0.70 in training and two external validation cohorts, respectively. An online dynamic nomogram was further developed for clinical applications (https://ruolinliu666.shinyapps.io/GIST/), offering predictive recurrence rates based on different treatment durations and tumor features.

Conclusions

We developed a nomogram to predict the recurrence risk for high‐risk patients according to tumor features and treatment durations of imatinib to help physicians on decision‐making for individualized treatment duration.

Application of ultrasonography in predicting the biological risk of gastrointestinal stromal tumors

OBJECTIVES

To explore and establish a reliable and noninvasive ultrasound model for predicting the biological risk of gastrointestinal stromal tumors (GISTs).

MATERIALS AND METHODS

We retrospectively reviewed 266 patients with pathologically-confirmed GISTs and 191 patients were included. Data on patient sex, age, tumor location, biological risk classification, internal echo, echo homogeneity, boundary, shape, blood flow signals, presence of necrotic cystic degeneration, long diameter, and short/long (S/L) diameter ratio were collected. All patients were divided into low-, moderate-, and high-risk groups according to the modified NIH classification criteria. All indicators were analyzed by univariate analysis. The indicators with inter-group differences were used to establish regression and decision tree models to predict the biological risk of GISTs.

RESULTS

There were statistically significant differences in long diameter, S/L ratio, internal echo level, echo homogeneity, boundary, shape, necrotic cystic degeneration, and blood flow signals among the low-, moderate-, and high-risk groups (all p < .05). The logistic regression model based on the echo homogeneity, shape, necrotic cystic degeneration and blood flow signals had an accuracy rate of 76.96% for predicting the biological risk, which was higher than the 72.77% of the decision tree model (based on the long diameter, the location of tumor origin, echo homogeneity, shape, and internal echo) (p = .008). In the low-risk and high-risk groups, the predicting accuracy rates of the regression model reached 87.34 and 81.82%, respectively.

CONCLUSIONS

Transabdominal ultrasound is highly valuable in predicting the biological risk of GISTs. The logistic regression model has greater predictive value than the decision tree model.

Prognostic Factors and Management of Colorectal Gastrointestinal Stromal Tumors

Introduction The gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. Even though it can be found in any location of the digestive tract, the colorectal GIST is rare. With this study, we aim to review the current knowledge regarding the prognosis and management of colorectal GIST.

Methods A literature search was conducted in PubMed, and 717 articles were collected. After analyzing these studies, 60 articles were selected to use in this review.

Results The mitotic index, as well as tumor size and location were identified as good discriminators of prognosis in various studies. Surgery remains the only curative therapy for potentially resectable tumors. However, even after surgical resection, some patients develop disease recurrence and metastasis, especially those with high-risk tumors. Therefore, surgical resection alone might be inadequate for the management of all colorectal GISTs. The discovery of GIST's molecular pathway led to a shift in its therapy, insofar as tyrosine kinase inhibitors became part of the treatment schemes for this tumor, revolutionizing the treatment's outcome and prognosis.

Discussion/Conclusion The controversy concerning colorectal GIST prognosis and treatment can be, in part, attributed to the limited number of studies in the literature. In this review, we gathered the most recent knowledge about the prognosis and management of GIST in this rare location and propose two algorithms for its approach. Lastly, we highlight the importance of an individualized approach in the setting of a multidisciplinary team.

A radiologic diagnostic scoring model based on CT features for differentiating gastric schwannoma from gastric gastrointestinal stromal tumors

We aimed to further explore the CT features of gastric schwannoma (GS), propose and validate a convenient diagnostic scoring system to distinguish GS from gastric gastrointestinal stromal tumors (GISTs) preoperatively. 170 patients with submucosal tumors pathologically confirmed (GS n=35; gastric GISTs n=135) from Hospital 1 were analyzed retrospectively as the training cohort, and 72 patients (GS=11; gastric GISTs=61) from Hospital 2 were enrolled as the validation cohort. We searched for significant CT imaging characteristics and constructed the scoring system via binary logistic regression and converted regression coefficients to weighted scores. The ROC curves, AUCs and calibration tests were carried out to evaluate the scoring models in both the training cohort and the validation cohort. For convenient assessment, the system was further divided into four score ranges and their diagnostic probability of GS was calculated respectively. Four CT imaging characteristics were ultimately enrolled in this scoring system, including transverse position (2 points), location (5 points), perilesional lymph nodes (6 points) and pattern of enhancement (2 points). The AUC of the scoring model in the training cohort were 0.873 (95% CI, 0.816-0.929) and the cutoff point was 6 points. In the validation cohort, the AUC was 0.898 (95% CI, 0.804-0.957) and the cutoff value was 5 points. Four score ranges were as follows: 0-3 points for very low probability of GS, 4-7 points for low probability; 8-9 points for middle probability; 10-15 points for very high probability. A convenient scoring model to preoperatively discriminate GS from gastric GISTs was finally proposed.