NCCN Task Force Report: Management of Patients with Gastrointestinal Stromal Tumor (GIST)—Update of the NCCN Clinical Practice Guidelines

Management of subepithelial esophageal tumors

Subepithelial esophageal tumors (SET) are normally benign intramural esophageal lesions of mesenchymal origin. Although rare, the incidence of SET has increased in recent decades due to the more widespread use of endoscopy and diagnostic imaging. The current review aims to provide an overview of the histopathologic spectrum and the most frequent entities including leiomyoma and gastrointestinal stromal tumor (GIST), diagnostic workup, and multidisciplinary treatment options. Staging for SET should include endoscopy, endoscopic ultrasonography (EUS), and tissue sampling. Current consensus guidelines recommend that SET suggestive of gastrointestinal stromal tumor (GIST) larger than 20 mm or lesions with high-risk stigmata should undergo tissue sampling. Most SET have an excellent long-term outcome, but malignancy may be present in certain subtypes. Asymptomatic SET without high-risk stigmata discovered incidentally usually do not require specific treatment. However, depending on the size and location of the lesion symptoms may occur. Therapeutic interventions range from endoscopic interventional resections to major surgical procedures. Enucleation via minimally invasive or robotic-assisted access remains the standard of care for most SET sub-entities.

Correlation of preoperative CT features with intra- and postoperative parameters of endoscopic resection in patients with gastric submucosal tumor (1~3 cm)

OBJECTIVES

Endoscopic resection of gastric submucosal tumors (SMTs) possesses minimal trauma, expedited recovery, and reduced costs. Nonetheless, intraoperative challenges, including imprecise surgical risk assessment, prevail. Hence, we investigated the correlation between preoperative CT observation features and perioperative parameters for predicting outcomes in SMT patients.

METHODS

Subjects diagnosed with SMT and undergoing endoscopic surgery conducted at West China Hospital's Endoscopy Center from September 2019 to October 2023 were retrospectively selected. Endoscopic ultrasonography (EUS) and computer tomography (CT) were utilized for evaluating SMT. The study assessed the correlation between preoperative CT findings and perioperative parameters.

RESULTS

Increased lesion size on contrast-enhanced CT correlates with increased operative duration, hospital stay, postoperative antibiotic use. Of utmost significance, we observed a significantly higher intraoperative perforation rate for patients with tumor outgrowth compared to those with lesion involvement of the lumen (96.88% vs 29.11%, P < 0.001). These patients also demonstrated an increased risk of postoperative blood stream infections (P = 0.012), necessitating higher antibiotic grade (P = 0.048), along with prolonged gastrostomy tube retention (P = 0.001) and hospitalization (P = 0.018). In addition, CT provides a more accurate and comprehensive assessment of tumor size (P = 0.037) and growth pattern (P = 0.026) than EUS.

CONCLUSION

CT assessment of tumor size closer to reality than EUS. Importantly, these features can assist in pinpointing lesions with elevated surgical complexity and high risk of complications, leading to improved preoperative preparation, thereby increasing anticipation of surgical risks and reducing incidence of complications.

Gastrointestinal stromal tumors mimicking as gynecological tumors-A case series

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors that arise from interstitial cells of Cajal. Due to vague presentation, location and confusing imaging studies, they tend to mimic gynaecological tumors. They usually diagnosed intra-operative and histopathology followed by tumor specific receptors such as KIT, CD34, CD 117 and DOG 1 are mainstay of diagnosis of GIST. Prognosis of GISTs depends on mitotic rate, tumor size and organ of origin. Resection of mass with tumor free margins is the target of treatment. L ymphadenectomy is not routine. Chemotherapy with tyrosine kinase inhibitors such as Imatinib, Dasatinib, Sorafenib and follow- up depend upon risk category. In this case series, there were four cases with vague symptoms misdiagnosed as gynaecological tumors are reviewed. Preoperatively tumors assumed to be of gynaecological origin were found to be case of GISTs intra-operatively and confirmed by presence of cajal's cells histopathology and mainly by DOG 1, CD117 and tyrosine kinase inhibitor receptors on immunohistochemistry. All belonged to high risk category of GISTs. Any abdomino-pelvic mass detected on ultrasonography and with unusual presentation presenting at primary health centre the possibility of non-gynecological tumors especially GISTs should be kept in mind and should be referred to higher centres for further investigation and proper management.

Performance of radiomics in preoperative determination of malignant potential and Ki-67 expression levels in gastrointestinal stromal tumors: a systematic review and meta-analysis

Empirical evidence for radiomics predicting the malignant potential and Ki-67 expression in gastrointestinal stromal tumors (GISTs) is lacking. The aim of this review article was to explore the preoperative discriminative performance of radiomics in assessing the malignant potential, mitotic index, and Ki-67 expression levels of GISTs. We systematically searched PubMed, EMBASE, Web of Science, and the Cochrane Library. The search was conducted up to 30 September 2023. Quality assessment was performed using the Radiomics Quality Score (RQS). A total of 35 original studies were included in the analysis. Among them, 26 studies focused on determining malignant potential, three studies on mitotic index discrimination, and six studies on Ki-67 discrimination. In the validation set, the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of radiomics in the determination of high malignant potential were 0.74 (95% CI=0.69-0.78), 0.90 (95% CI=0.83-0.94), and 0.81 (95% CI=0.14-0.99), respectively. For moderately to highly malignant potential, the sensitivity, specificity, and AUC were 0.86 (95% CI=0.83-0.88), 0.73 (95% CI=0.67-0.78), and 0.88 (95% CI=0.27-0.99), respectively. Regarding the determination of high mitotic index, the sensitivity, specificity, and AUC of radiomics were 0.86 (95% CI=0.83-0.88), 0.73 (95% CI=0.67-0.78), and 0.88 (95% CI=0.27-0.99), respectively. When determining high Ki-67 expression, the combined sensitivity, specificity, and AUC were 0.74 (95% CI=0.65-0.81), 0.81 (95% CI=0.74-0.86), and 0.84 (95% CI=0.61-0.95), respectively. Radiomics demonstrates promising discriminative performance in the preoperative assessment of malignant potential, mitotic index, and Ki-67 expression levels in GISTs.

Gastrointestinal stromal tumors in fine-needle aspiration biopsies

Gastrointestinal stromal tumors (GISTs), although rare, are the most common mesenchymal neoplasms of the gastrointestinal tract. Their potential for malignancy underscores the significance of identifying them through cytomorphologic findings and pertinent immunohistochemical markers. GISTs can emerge anywhere along the gastrointestinal tract with a predilection for the stomach. The clinical manifestations vary from nonspecific abdominal symptoms to incidental discovery during diagnostic interventions for unrelated signs and symptoms. Cytologically, GIST aspirates contain spindle or epithelioid cells with immunoreactivity for CD117/c-KIT, DOG-1, and CD34. Molecularly, KIT or PDGFRA mutations are prevalent, guiding targeted therapy with tyrosine kinase inhibitors. Distinct subtypes like succinate dehydrogenase-deficient GISTs pose challenges, often affecting younger individuals and displaying unique features. Histologically, GISTs are graded by mitotic rates, aiding prognostication. Distinguishing GISTs from similar entities is pivotal, necessitating attention to their immunostaining patterns for making an accurate diagnosis and molecular alterations for effectively planning treatment. Common differential diagnoses include leiomyoma, schwannoma, and solitary fibrous tumor. This article presents a classic GIST case and showcases relatively simple diagnostic clues for identifying similar lesions that may occur in diverse locations.

Is laparoscopic approach as treatment of large gastric GIST acceptable?

AIM

Laparoscopic surgery is widely used for small gastric gastrointestinal stromal tumors (GISTs) (≤ 5 cm) but remains a controversial approach for larger gastric GISTs (> 5 cm). This study aims to compare short- and long-term outcomes of laparoscopic resection in comparison with open resection for gastric GISTs measuring over 5 cm.

METHOD

All patients receiving surgery for gastric GIST > 5 cm between 2000 and 2021 in a single tertiary hospital were included. Data were collected from prospectively maintained records. Kaplan-Meier method and log rank test were used to compare survival outcomes.

RESULTS

Among 108 included patients, 59 patients had minimally invasive (MI) surgery (54.6%) whereas 49 patients had open surgery (46.4%). The rate of overall postoperative morbidity was 14.8% and the median length was significantly shorter in the MI group [4 (range 2-30) vs. 7 (range 4-33) days; P = 0.007]. The overall R0 resection rate was 98.2% and the rate of tumor rupture was 13%, not different between the two groups. Recurrence occurred in 24% of the whole population without any difference between groups (20.3% vs. 28.7%, p = 0.31). Minimally invasive surgery was not found as a negative prognostic disease-free survival factor.

CONCLUSION

Laparoscopic surgery could be a safe and feasible alternative to open surgery in large gastric GIST, bringing the benefits of minimally invasive surgery without compromising oncologic results.

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

Background

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

Methods

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

Results

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

Conclusions

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

Hybrid surgical approach excision of gastrointestinal stromal tumor (GIST): A case report of GIST at an unusual location and review of the literature

Gastrointestinal stromal tumors are the most common malignant subepithelial lesions involving the gastrointestinal tract. Surgical techniques have been the mainstay of treatment, however, in recent times hybrid surgeries are being introduced yielding better clinical 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.

A gist on an obscure neoplasm in Ghana: gastrointestinal stromal tumours

BACKGROUND

Gastrointestinal Stromal Tumour is a rare but potentially curable tumour of the gastrointestinal tract accounting for up to 1% of all gastrointestinal tumours. The discovery of Imatinib mesylate, a novel tyrosine kinase inhibitor has improved the chances even for unresectable, recurrent, or metastatic diseases.

METHODS

This study sought to document the clinical and pathological characteristics of GISTs from two tertiary hospitals in Ghana that have undergone immunohistochemistry confirmation between 2014 and 2021.

RESULTS

The median age of the subjects was 50 years with most of them (28.0%) being above 61 years. There were more females than males (64.0% vs. 36.0%). Abdominal mass and abdominal pain made up the majority of the clinical presentations. The majority of the subjects had partial gastrectomy (32.0%) which was followed by wedge resection (28.0%). Appendectomy and sleeve gastrectomy were the least performed procedures (8% each). Four of the 25 patients (16.0%) had resections of involved contiguous organs done with splenectomy being the most common procedure. The majority of GISTs were found in the stomach (68.0%) followed by the appendix (12.0%) and small bowel (12.0%). Gastrointestinal bleeding (55.8%) and abdominal pain (38.5%) were the most reported symptoms. Free resection margins were observed in 84.0% of the subjects and only 3/25 (12.0%) experienced tumour recurrence.

CONCLUSION

GIST is a potentially curable tumour that once was obscure but currently gaining popularity. Surgical resection offers the hope of a cure for localized disease while targeted therapies is a viable option for recurrent, metastatic, or unresectable tumours.

Gastrointestinal Stromal Tumor Complicated by Fistula Formation

Gastrointestinal (GI) stromal tumors are mesenchymal tumors that may arise in any portion of the GI tract. Their clinical presentation and complications may vary but do not often present with fistulization. This case is of clinical interest because of the rarity of GI stromal tumor intestinal fistulas.

The Association between the Growth Pattern and Malignancy in the Formation of Ulceration in Gastric Gastrointestinal Stromal Tumor

Objective In general, surface ulceration in gastric gastrointestinal stromal tumor (GIST) is considered a malignant feature; however, the mechanism underlying its formation has not been evaluated in detail. In this study, we analyzed the factors involved in ulceration using resected specimens of gastric GIST. Methods A total of 48 samples were retrospectively analyzed. We examined the association of surface ulceration of gastric GIST with the MIB-1 labeling index, mitotic number, tumor size, endoscopic ultrasound (EUS) findings and growth pattern on computed tomography (CT). Results The proportion of men was significantly higher in the ulceration group than in the non-ulceration group (p=0.04146), whereas age was not significantly different between the groups. Tumor was significantly larger in the ulceration group than in the non-ulceration group (p=0.0048). There was no correlation between tumor size and ulcer number. The MIB-1 index was not related to ulceration, nor were EUS findings. The number of mitotic cells tended to be higher in the ulceration group than in the non-ulceration group (p=0.05988). Intraluminal growth pattern was strongly associated with ulceration (p=0.00019). After a multivariate analysis, the growth pattern was the only factor associated with ulceration of gastric GIST. Conclusion Although formation of surface ulceration in gastric GIST was partially associated with the degree of malignancy, the growth pattern was the most important factor associated with ulceration in gastric GIST.

2023 GEIS Guidelines for gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GIST) is the most common malignant neoplasm of mesenchymal origin. GIST spans a wide clinical spectrum that ranges from tumors with essentially no metastatic potential to malignant and life-threatening spread diseases. Gain-of-function mutations in KIT or PDGFRA receptor tyrosine kinases are the crucial drivers of most GISTs, responsible for tumor initiation and evolution throughout the entire course of the disease. The introduction of tyrosine kinase inhibitors targeting these receptors has substantially improved the outcomes in this formerly chemoresistant cancer. As of today, five agents hold regulatory approval for the treatment of GIST: imatinib, sunitinib, regorafenib, ripretinib, and avapritinib. This, in turn, represents a success for a rare neoplasm. During the past two decades, GIST has become a paradigmatic model in cancer for multidisciplinary work, given the disease-specific particularities regarding tumor biology and tumor evolution. Herein, we review currently available evidence for the management of GIST. This clinical practice guideline has been developed by a multidisciplinary expert panel (oncologist, pathologist, surgeon, molecular biologist, radiologist, and representative of patients' advocacy groups) from the Spanish Group for Sarcoma Research, and it is conceived to provide, from a critical perspective, the standard approach for diagnosis, treatment, and follow-up.

An Overview of In Vitro Assays of 64Cu-, 68Ga-, 125I-, and 99mTc-Labelled Radiopharmaceuticals Using Radiometric Counters in the Era of Radiotheranostics

Radionuclides are unstable isotopes that mainly emit alpha (α), beta (β) or gamma (γ) radiation through radiation decay. Therefore, they are used in the biomedical field to label biomolecules or drugs for diagnostic imaging applications, such as positron emission tomography (PET) and/or single-photon emission computed tomography (SPECT). A growing field of research is the development of new radiopharmaceuticals for use in cancer treatments. Preclinical studies are the gold standard for translational research. Specifically, in vitro radiopharmaceutical studies are based on the use of radiopharmaceuticals directly on cells. To date, radiometric β- and γ-counters are the only tools able to assess a preclinical in vitro assay with the aim of estimating uptake, retention, and release parameters, including time- and dose-dependent cytotoxicity and kinetic parameters. This review has been designed for researchers, such as biologists and biotechnologists, who would like to approach the radiobiology field and conduct in vitro assays for cellular radioactivity evaluations using radiometric counters. To demonstrate the importance of in vitro radiopharmaceutical assays using radiometric counters with a view to radiogenomics, many studies based on ⁶⁴Cu-, ⁶⁸Ga-, ¹²⁵I-, and ^99mTc-labeled radiopharmaceuticals have been revised and summarized in this manuscript.

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.

Improving Outcomes in the Advanced Gastrointestinal Stromal Tumors: The Role of the Multidisciplinary Team Discussion Intervention

Objectives: There is disagreement over the prognostic value of multidisciplinary team (MDT) discussion for advanced gastrointestinal stromal tumors (GISTs). This study examined how an MDT affected patients with advanced GISTs in terms of their overall survival (OS) and whether it may enhance their performance status (PS). Methods: A retrospective data analysis was conducted on patients with advanced GISTs between 2000 and 2022. Depending on whether they had received the MDT discussion intervention, the patients were split into two groups. The OS between the two groups was compared using the Kaplan–Meier method. A multivariate Cox regression analysis was used to analyze the prognostic variables for advanced GIST. Fisher’s test was used to investigate the relationship between an MDT and PS. Results: There were 122 patients with an MDT and 117 patients without an MDT in this study. In comparison to the non-MDT group, the MDT group showed a higher survival rate (5-year OS, 42.62% vs. 28.21%, p < 0.05). MDT was an independent prognostic factor for OS in univariate and multivariate Cox regression analyses (p < 0.05). Fisher’s test revealed that there were variations in PS between the two groups (p < 0.05). Conclusions: The effectiveness of an MDT in the treatment of advanced GIST was examined for the first time in this study. MDT discussion intervention is an effective measure for improving the outcomes of patients with advanced GISTs.

Impact of ABCG2 and ABCB1 Polymorphisms on Imatinib Plasmatic Exposure: An Original Work and Meta-Analysis

Adequate imatinib plasma levels are necessary to guarantee an efficacious and safe treatment in gastrointestinal stromal tumor (GIST) and chronic myeloid leukemia (CML) patients. Imatinib is a substrate of the drug transporters ATP-binding cassette subfamily B member 1 (ABCB1) and ATP-binding cassette subfamily G member 2 (ABCG2) that can affect its plasma concentration. In the present study, the association between three genetic polymorphisms in ABCB1 (rs1045642, rs2032582, rs1128503) and one in ABCG2 (rs2231142) and the imatinib plasma trough concentration (C_trough) was investigated in 33 GIST patients enrolled in a prospective clinical trial. The results of the study were meta-analyzed with those of other seven studies (including a total of 649 patients) selected from the literature through a systematic review process. The ABCG2 c.421C>A genotype demonstrated, in our cohort of patients, a borderline association with imatinib plasma trough levels that became significant in the meta-analysis. Specifically, homozygous carriers of the ABCG2 c.421 A allele showed higher imatinib plasma C_trough with respect to the CC/CA carriers (C_trough, 1463.2 ng/mL AA, vs. 1196.6 ng/mL CC + AC, p = 0.04) in 293 patients eligible for the evaluation of this polymorphism in the meta-analysis. The results remained significant under the additive model. No significant association could be described between ABCB1 polymorphisms and imatinib C_trough, neither in our cohort nor in the meta-analysis. In conclusion, our results and the available literature studies sustain an association between ABCG2 c.421C>A and imatinib plasma C_trough in GIST and CML patients.

The Application of Virtual Therapeutic Drug Monitoring to Assess the Pharmacokinetics of Imatinib in a Chinese Cancer Population Group

PURPOSE

Imatinib is used in gastrointestinal stromal tumours (GIST) and chronic myeloid leukaemia (CML). Oncology patients demonstrate altered physiology compared to healthy adults, e.g. reduced haematocrit, increased α-1 acid glycoprotein, decreased albumin and reduced glomerular filtration rate (GFR), which may influence imatinib pharmacokinetics. Given that Chinese cancer patients often report raised imatinib plasma concentrations and wider inter-individual variability reported in trough concentration when compared to Caucasian cancer patients, therapeutic drug monitoring (TDM) has been advocated.

METHOD

This study utilised a previously validated a Chinese cancer population and assessed the impact of imatinib virtual-TDM in Chinese and Caucasian cancer populations across a dosing range from 200-800 mg daily.

RESULTS

Staged dose titration to 800 mg daily, resulted in recapitulation to within the target therapeutic range for 50 % (Chinese) and 42.1% (Caucasian) subjects possessing plasma concentration < 550 ng/mL when dosed at 400 mg daily. For subjects with plasma concentrations >1500 ng/mL when dosed at 400 mg daily, a dose reduction to 200 mg once daily was able to recover 67 % (Chinese) and 87.4 % (Caucasian) patients to the target therapeutic range.

CONCLUSION

Virtual TDM highlights the benefit of pharmacokinetic modelling to optimising treatments in challenging oncology population groups.

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.

Laparoscopic resection is not superior to endoscopic resection for relative small gastric gastrointestinal stromal tumors: A propensity score-matched study

BACKGROUND AND AIM

Endoscopic resection (ER) and laparoscopic resection (LAP) have been recommended for the treatment of gastric gastrointestinal stromal tumors (GISTs) less than 2 cm. However, the therapeutic approach for gastric GISTs between 2 and 5 cm in diameter is still under debate. In this retrospective study, we aimed to evaluate the feasibility, efficacy, and safety of ER for gastric GISTs (2-5 cm) compared with LAP.

METHODS

From January, 2011 to January, 2018, 197 patients with GISTs at our institution with tumor diameter between 2 and 5 cm were included in our study. Clinical baseline characteristics, histopathological results, and perioperative outcomes were collected and compared in all the patients. Propensity score matching (PSM) methods were used to balance baseline characteristics.

RESULTS

There was no significant difference in age (p = 0.246), gender (p = 0.572), tumor location (p = 0.333), pathological risk classification (p = 0.543), Ki-67 index (p = 0.212), and follow-up time (p = 0.831) in the ER and LAP groups. However, significance difference was found in times to liquid diet intake (4.45 ± 1.2 vs. 5.40 ± 1.5 days, p = 0.013) and hospital stays (7.72 ± 1.1 vs. 10.01 ± 1.3 days, p < 0.001). During the follow-up period, there was one recurrence in the ER group vs. two recurrences in the LAP group. After PSM, the tumor size was balanced between the two groups with 49 patients in each group. The times to liquid diet intake (4.18 ± 1.3 vs. 5.16 ± 1.6 days, p = 0.042) and hospital stay days (7.12 ± 1.1 vs. 9.94 ± 1.3, p < 0.0001) were still short in the ER group.

CONCLUSIONS

ER is more associated with a quick postoperative recovery than LAP. ER could be an alternative approach for gastric GISTs (2-5 cm). However, the long-term follow-up outcomes are still unclear and random control trials are needed.

Is minimally invasive surgery for large gastric GIST actually safe? A comparative analysis of short- and long-term outcomes

INTRODUCTION

While minimally invasive surgery (MIS) is frequently utilized to remove small gastric gastrointestinal stromal tumors (GIST), MIS surgery for tumors ≥ 5 cm is currently not endorsed by national guidelines as standard of care due to concerns of safety and inferior oncologic outcomes. Hence this study investigates the perioperative and long-term outcomes of MIS for T3 gastric GIST measuring 5-10 cm.

METHODS

The National Cancer Database (NCDB) 2017 was queried for gastric GIST measuring 5-10 cm or T3 category. Inclusion criteria were known: stage, size, comorbidities, grade, lymphovascular invasion, type of surgery, approach, conversion info, margin status, mitotic rate, neoadjuvant and adjuvant treatment, hospital stay, readmission, 30- and 90-day mortality, complete follow-up, type of institution, and hospital gastric surgery case volume. Binary logistic regression, linear regression models, and Kaplan-Meier survival analysis were used.

RESULTS

In 3765 patients, mean tumor size was 67.3 mm; 26.3% MIS; and 73.8% open. Median hospital stay was shorter for MIS (4.77 vs 7.04 days, p < 0.001). There was no significant difference in incidence of R1 margins [2.9% MIS vs. 3.1% open (p = 0.143)], unplanned readmission [2.9% MIS and 4.1% open (OR 0.474 p = 0.025)], 30-day mortality [0.5% MIS vs 1.2% open (OR 0.325, p = 0.031)], and 90-day mortality [0.9% MIS vs 2.1% open (OR 0.478 p = 0.036)]. Cox regression models for OS showed no difference in survival (p = 0.137, HR 0.808).

CONCLUSION

This analysis provides substantial evidence that MIS for gastric GIST ≥ 5-10 cm may not only offer improved postoperative morbidity but also oncologic safety. Moreover, as both approaches lead to similar long-term survival, national guidelines may need to incorporate this new information.

Necessity of Individualized Approach for Gastric Subepithelial Tumor Considering Pathologic Discrepancy and Surgical Difficulty Depending on the Gastric Location

Background: Depending on the location of gastric subepithelial tumors (SETs), surgical access is difficult with a risk of postoperative complications. This study aimed to evaluate the clinicopathological characteristics of small-sized gastric SETs and their surgical outcomes depending on location and provide considering factors for their treatment plans. Methods: This single-center, retrospective study reviewed patients who underwent surgical resection for gastric SETs (size < 5 cm). SETs were divided into benign SETs and gastrointestinal stromal tumors (GISTs) for comparison. The clinicopathological characteristics of SETs in the cardia were compared to those in the other regions. Results: Overall, 191 patients with gastric SETs (135 GISTs, 70.7%; and 56 benign SETs, 29.3%) were included. In multivariate analysis, age > 65 years (odds ratio (OR), 3.183; 95% confidence interval (CI), 1.310−7.735; p = 0.011), and non-cardiac SETs (OR, 2.472; 95% CI, 1.110−5.507; p = 0.030) were associated with a significant risk of malignancy. Compared to SETs in other locations, cardiac SETs showed more complications (3 versus 0; p = 0.000), and open conversion rates (2 versus 0; p = 0.003). However, the proportion of GISTs of SETs in the cardia is not negligible (52.9%). Conclusions: Considering the malignancy risk of SETs, active surgical resection should be considered in old age and/or location in the non-cardiac area. However, in young patients, SETs located in the gastric cardia have a considerably benign nature and are associated with poor short-term surgical outcomes. An individualized surgical approach for asymptomatic small SETs according to the gastric location is warranted.

Effect of endoscopic resection of gastrointestinal stromal tumors in the stomach under double-channel gastroscopy: A retrospective observational study

We aimed to investigate the safety and efficacy of endoscopic resection for the treatment of gastric gastrointestinal stromal tumors (GISTs) under single-channel gastroscopy and double-channel gastroscopy. We identified 154 patients with GISTs of the stomach who underwent endoscopic resection and were retrospectively analyzed at our hospital between May 2016 and March 2020, including 49 patients by single-channel gastroscopy and 105 patients by double-channel gastroscopy. We observed the clinical efficacy, complications, and safety of endoscopic resection of gastric GISTs, and the data were evaluated retrospectively. All patients underwent endoscopic resection successfully, without conversion to open surgery. In the single-channel gastroscopy group, 7 patients had lesions in the gastric cardia, 17 in the gastric fundus, 20 in the gastric corpus, and 5 in the gastric antrum. In the double-channel gastroscopy group, 13 patients had lesions in the gastric cardia, 34 in the gastric fundus, 46 in the gastric body, 10 in the gastric antrum, 1 in the pylorus, and 1 in the gastric angular incisure. The double-channel gastroscopy group had a shorter operation time than the single-channel gastroscopy group (59.9 ± 34.9 minutes vs 74.8 ± 26.7 minutes; P = .009 and P < .01, respectively), while they also had a lower perforation rate than the single-channel gastroscopy group (34.3% vs 51.0%; P = .048 and P < .05, respectively). No residual or recurrent lesions were discovered in any patients by gastroscopy reexamination. Both single-channel gastroscopy and double-channel gastroscopy can provide safe, effective, feasible endoscopic resection. However, double-channel gastroscopy has some distinct advantages in endoscopic resection.

Safety and feasibility of laparoscopy-assisted surgery for gastrointestinal stromal tumors larger than 5 cm: Results of a retrospective, single-center series of 1,802 consecutive patients

BACKGROUND

The role of laparoscopy-assisted resection for treating gastrointestinal stromal tumors >5 cm is still disputed. We aimed to assess the advantages of laparoscopy-assisted resection for treating gastrointestinal stromal tumors >5 cm.

METHODS

In total, 1,802 patients with primary gastrointestinal stromal tumors who underwent laparoscopy-assisted surgery or open surgery were retrospectively evaluated. Propensity score matching was performed to reduce confounders.

RESULTS

In total, 518 patients with tumor size >5 cm were enrolled in this study (males: 292, 56.4%; females: 226, 43.6%; median age: 58 years, range: 23-85 years). One hundred and twenty-three (23.7%) patients underwent laparoscopy-assisted resection, and 395 (76.3%) patients underwent open resection. After propensity score matching, 190 patients were included (95 in each group). The laparoscopy-assisted surgery group was superior to the open surgery group considering the blood loss (>200 mL: 6.3% vs 22.1%, P = .005), length of midline incision (6.0 ± 0.9 cm vs 9.6 ± 2.1 cm, P < .001), time to first flatus (49.7 ± 10.5 hours vs 63.9 ± 7.4 hours, P < .001), and shorter hospital stay (10.3 ± 3.2 days vs 11.9 ± 2.9 days, P < .001). The difference in relapse-free survival or overall survival between the laparoscopy-assisted surgery and open surgery groups after matching was not significant (all P > .05). On subgroup analysis, the relapse-free survival and overall survival of the laparoscopy-assisted surgery group were comparable to those of the open surgery group, irrespective of tumor location (gastric or nongastric locations) (all P > .05).

CONCLUSION

When performed by experienced surgeons, laparoscopy-assisted resection is feasible and safe for gastrointestinal stromal tumors >5 cm, which showed improved short-term outcomes and comparable oncological outcomes, regardless of whether the tumor had a gastric or nongastric location.

Next questions for the medical treatment of gastrointestinal stromal tumor

PURPOSE OF REVIEW

Since its approval in 2002, imatinib remains the standard first-line treatment for patients with advanced gastrointestinal stromal tumors (GISTs). Overall, all the drugs approved for patients who have developed secondary resistance to imatinib are less effective than imatinib in first-line. Even if, overall survival of patients with advanced GIST has improved over time the last 20 years, imatinib-resistant GIST remains therefore a difficult-to-treat cancer. The aim of this review is to elaborate on the potential strategies to improve outcome for patients with imatinib-refractory disease.

RECENT FINDINGS

New-generation potent KIT and PDGFRA inhibitors such as ripretinib and avapritinib developed for the treatment of GIST have shown very promising clinical activity in patients with highly refractory disease. However, both failed to improve outcome in comparison with standard of care in earlier lines settings. Clinical trials investigating the efficacy of multikinase inhibitor with highly specific KIT inhibitors are currently ongoing. Targeting the microenvironment of GIST may also represent a promising approach and is investigated in several clinical studies.

SUMMARY

Imatinib-refractory GIST still represent a therapeutic challenge. It is likely that only combination therapies with new generation of tyrosine kinase inhibitors (TKIs) and/or immune-oncology agents might potentially result in an enhanced therapeutic efficacy compared with current standard of care.

The GIST of Advances in Treatment of Advanced Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumor (GIST) is the most common malignant neoplasm of mesenchymal origin and a compelling clinical and biologic model for the rational development of molecularly targeted agents. This is because the majority of GISTs are driven by gain-of-function mutations in KIT or PDGFRA receptor tyrosine kinases. Specific GIST mutations circumscribe well-defined molecular subgroups that must be determined during the diagnostic work-up to guide clinical management, including therapeutic decisions. Surgery is the cornerstone treatment in localized disease and can also be clinically relevant in the metastatic setting. The correct combination and sequence of targeted agents and surgical procedures improves outcomes for patients with GIST and should be discussed individually within multidisciplinary expert teams. All currently approved agents for the treatment of GIST are based on orally available tyrosine kinase inhibitors targeting KIT and PDGFRA oncogenic activation. Although first-line imatinib achieves remarkable prolonged disease control, the benefit of subsequent lines of treatment is more modest. Novel therapeutic strategies focus on overcoming the heterogeneity of KIT or PDGFRA secondary mutations and providing more potent inhibition of specific challenging mutations. This article reviews the current understanding and treatment of GIST, with an emphasis on recent advances.

Laparoscopic Versus Open Surgery for Rectal Gastrointestinal Stromal Tumor: A Multicenter Propensity Score-Matched Analysis

BACKGROUND

The safety and feasibility of laparoscopic surgery for the management of rectal gastrointestinal stromal tumors are unknown.

OBJECTIVE

This study aimed to compare the surgical and oncologic results of laparoscopic versus open surgery for the treatment of rectal gastrointestinal stromal tumors.

DESIGN

This was a retrospective multicenter propensity score-matched study to minimize heterogeneity between groups and focus on the difference between surgery strategies.

SETTINGS

Eleven Chinese tertiary hospitals participated in this study.

PATIENTS

A total of 364 patients with pathologically confirmed rectal gastrointestinal stromal tumors were retrospectively analyzed.

MAIN OUTCOME MEASURES

Relapse-free survival, postoperative hospital stay length, and 30-day postoperative complication rate were the main outcome measures.

RESULTS

We enrolled 214 patients who underwent surgical operation for primary localized rectal gastrointestinal stromal tumors. After propensity score matching, 134 cases involved in the comparison (67 laparoscopic vs 67 open surgery) were randomly matched (1:1) by sex, age, tumor size, tumor site, and neoadjuvant therapy. The laparoscopic surgery group had superior relapse-free survival (χ2 = 4.46, p = 0.04), and fewer complications (6.0% vs 25.4%, p = 0.002). No significant difference was found in the length of postoperative hospital stay between the laparoscopic surgery and open surgery groups (9.66 ± 5.42 vs. 10.64 ± 4.93, p = 0.28). Subgroup analysis showed that the laparoscopic surgery group had superior relapse-free survival (χ2 = 4.14, p = 0.04) and fewer complications after surgery (2.9% vs 24.4%, p = 0.01) in the rectal gastrointestinal stromal tumors ≤5 cm subgroup.

LIMITATIONS

This study was limited by the nature of retrospective reviews and relatively short follow-up period.

CONCLUSIONS

Laparoscopic surgery offers a safe and feasible option for the radical resection of primary localized rectal gastrointestinal stromal tumors, especially for patients with rectal gastrointestinal stromal tumors ≤5 cm. See Video Abstract at http://links.lww.com/DCR/B764.

CIRUGA LAPAROSCPICA VERSUS CIRUGA ABIERTA PARA TUMORES DEL ESTROMA GASTROINTESTINAL DE RECTO UN ANLISIS MULTICNTRICO EMPAREJADO POR PUNTAJE DE PROPENSIN

ANTECEDENTES:Se desconoce la seguridad y factibilidad de la cirugía laparoscópica para el tratamiento de los tumores del estroma gastrointestinal de recto.OBJETIVO:Comparar los resultados quirúrgicos y oncológicos de la cirugía laparoscópica versus cirugía abierta para el tratamiento de los tumores del estroma gastrointestinal de recto.DISEÑO:Estudio retrospectivo multicéntrico emparejado por puntuación de propensión para minimizar la heterogeneidad entre los grupos y centrarse en las diferencias entre las estrategias quirúrgicas.AJUSTES:Once hospitales terciarios de la China participaron en este estudio.PACIENTES:Se analizaron retrospectivamente un total de 364 pacientes con tumores del estroma gastrointestinal de recto confirmados patológicamente.PRINCIPALES MEDIDAS DE VALORACION:Supervivencia sin recidiva, duración de la estancia hospitalaria postquirúrgica y tasa de complicaciones postquirúrgicas a los 30 días.RESULTADOS:Inscribimos a 214 pacientes que fueron sometidos a cirugía por tumores primariamente localizados del estroma gastrointestinal de recto. Después del emparejamiento por puntaje de propensión, 134 casos involucrados en la comparación (67 laparoscópicos versus 67 cirugía abierta) fueron emparejados aleatoriamente (1: 1) por sexo, edad, tamaño del tumor, sitio del tumor y terapia neoadyuvante. El grupo de cirugía laparoscópica tuvo una supervivencia sin recidiva superior (χ2 = 4,46, p = 0,04) y menos complicaciones (6,0% frente a 25,4%, p = 0,002). No se encontraron diferencias significativas en la duración de la estancia hospitalaria postquirúrgica entre los grupos de cirugía laparoscópica y cirugía abierta (9,66 ± 5,42 frente a 10,64 ± 4,93, p = 0,28). El análisis de subgrupos mostró que el grupo de cirugía laparoscópica tuvo una supervivencia sin recidiva superior (χ2 = 4,14, p = 0,04) y menos complicaciones después de la cirugía (2,9% frente a 24,4%, p = 0,01) en el subgrupo de tumores del estroma gastrointestinal de recto ≤ 5 cm.LIMITACIONES:La naturaleza de la revisión retrospectiva y el período de seguimiento relativamente corto son limitaciones de este estudio.CONCLUSIONES:La cirugía laparoscópica ofrece una opción segura y factible para la resección radical de tumores primariamente localizados del estroma gastrointestinal de recto, especialmente para pacientes con tumores ≤5 cm. Consulte Video Resumen en http://links.lww.com/DCR/B764.

Mesenchymal Neoplasms of the Prostate and Seminal Vesicles: Spectrum of Disease with Radiologic-Pathologic Correlation

There is a wide spectrum of benign and malignant mesenchymal neoplasms of the prostate, which account for less than 1% of all prostatic tumors. These include distinctive tumors that arise from the specialized prostatic stroma and site-agnostic neoplasms such as smooth muscle tumors, fibrous or myofibroblastic neoplasms, neurogenic tumors, vascular tumors, and a plethora of sarcomas. Select tumors show classic sites of origin within the prostate. While stromal tumors of uncertain malignant potential (STUMPs) commonly involve the peripheral zone at the prostate base, leiomyomas typically originate from the central prostate toward the apex. Some "prostatic" neoplasms such as gastrointestinal stromal tumors, solitary fibrous tumor (SFT), paragangliomas, and neurogenic tumors arise primarily from periprostatic soft tissues. Most mesenchymal tumors of the prostate and seminal vesicles manifest as large tumors that cause nonspecific symptoms; prostate-specific antigen level is not typically elevated. Diverse mesenchymal neoplasms demonstrate characteristic histopathologic and immunocytochemical features and variable cross-sectional imaging findings. While leiomyoma and SFT typically display low signal intensity on T2-weighted images, synovial sarcomas commonly show hemorrhage. Diagnosis is difficult because of the rarity and lack of awareness of the tumors and the significant overlap in histopathologic features. Select tumors show characteristic genetic abnormalities that allow the diagnosis to be established. For example, more than 90% of SFTs are characterized by a unique NAB2-STAT6 gene fusion, and more than 95% of synovial sarcomas are associated with a distinctive SYT-SSX chimeric transcript. Accurate diagnosis is imperative for optimal management owing to markedly different tumor biology as well as attendant therapeutic and prognostic implications. While STUMPs commonly recur, sarcomas typically charter an aggressive course with poor prognosis. Online supplemental material is available for this article. ^©RSNA, 2022.

Gastrointestinal stromal tumor of the small intestine with lung metastasis

Gastrointestinal stromal tumours (GISTs) represent 1% of primary gastrointestinal cancers. These tumors most frequently metastasise to the liver and peritoneum and rarely to the lungs. We report the case of a 79-year-old woman with gastrointestinal stromal tumor of the small intestine and pulmonary metastases. Contrast-enhanced computed tomography (CT) revealed a focal mass centered around the last intestinal loop associated with pulmonary bilateral masses. The diagnosis of gist of the small bowel was confirmed by histopathological and immunohistochemical analyses of bioptic material obtained from CT guided biopsy of pulmonary lesions. To the best of our knowledge, only few cases had been reported in medical literature as This mode of presentation is unusual, with computed tomography (CT) playing a significant role in the diagnosis and management.

[Surgical and interdisciplinary treatment of gastrointestinal stromal tumors]

Gastrointestinal stromal tumors (GISTs) are the most frequent potentially malignant mesenchymal tumors of the gastrointestinal tract. The treatment of GISTs has been revolutionized since imatinib and other tyrosine kinase inhibitors were introduced for the treatment of GISTs, which inhibit the tyrosine kinases c‑KIT and platelet-derived growth factor receptor (PDGFR) alpha. Even after the introduction of this targeted treatment GISTs can only be cured by surgical resection. With interdisciplinary multimodal treatment the prognosis of metastasized GIST can now be further improved by surgical resection of the primary tumor and the metastases, potentially leading to a cure. Neoadjuvant therapy can reduce the extent of surgical resection and hereby enable organ preservation and reduce surgical morbidity. To evaluate molecular and clinical predictors and to offer an optimal therapeutic plan, patients with GISTs and certainly patients with advanced GISTs should be evaluated by interdisciplinary sarcoma boards.

Targeted therapy for drug-tolerant persister cells after imatinib treatment for gastrointestinal stromal tumours

BACKGROUND

Despite the effectiveness of tyrosine kinase inhibitors (TKI), gastrointestinal stromal tumours (GIST) develop after the withdrawal of TKI. Based on previous studies, a subpopulation of drug-tolerant cells called "persister cells" may be responsible for the recurrence and have thus, gained attention as a novel target in cancer therapy.

METHODS

The metabolic changes were investigated in imatinib-derived persister GIST cells. We investigated the efficacy and the mechanism of GPX4 inhibitor, which is known as a major inducer of "ferroptosis". We also evaluated the effects of RSL3 to the gefitinib-derived persister lung cancer cells.

RESULTS

We demonstrated a downregulation of glucose metabolism, subsequent decrease in the glutathione level and sensitivity to glutathione peroxidase 4 (GPX4) inhibitor, RSL3 in persister cells. As the cell death induced by RSL3 was found to be "iron-dependent" and "caspase-independent", loss of GPX4 function could have possibly induced selective persister cell ferroptotic death. In the xenograft model, we confirmed the inhibition of tumour regrowth after discontinuation of imatinib treatment. Moreover, RSL3 prevented the growth of gefitinib-derived persister lung cancer cells.

CONCLUSIONS

RSL3 combined with TKI may be a promising therapy for both GIST and epidermal growth factor receptor-mutated lung cancer.

The Pathologic Confirmation in Subepithelial Tumors

Background/Aims: Subepithelial tumors (SETs) are small, mostly asymptomatic lesions with normal overlying mucosa, usually identified incidentally on endoscopy. The aim of this study was to evaluate the pathologic diagnosis of SETs, and to assess the diagnostic yield and impact of endoscopic submucosal dissection (ESD) biopsy on the management of patients with SETs.Materials and Methods: We included 52 subepithelial lesions in this study during the study period. Inclusion criteria included size of the SET >2 cm, and a gastrointestinal stromal tumor (GIST) that cannot be excluded using EUS. We performed an endoscopic biopsy of each SET using the ESD technique.Results: The mean diameter of the lesions was 24.15±6.0 mm. The diagnostic yield of this method was 96.15%. Among the 52 participants, 45 were located in the stomach, four in the esophagus, and three in the duodenum. The pathologic diagnoses included: 17 leiomyomas, 13 GISTs, 11 ectopic pancreases, two carcinomas, two inflammatory fibroid polyps, two Brunner’s gland hyperplasia, two lipomas, one glomus tumor, and two remained undiagnosed. The mean duration of the procedure was 13.44±2.41 minutes. Three complications were associated with the procedure.Conclusions: Deep biopsy via ESD is useful in determining the histopathologic nature of SETs. This method minimizes the need for unnecessary surgery in benign SETs.

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

Simple Summary

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

Abstract

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

Gastrointestinal stromal tumor with maxillary metastasis: a case report and literature review

Gastrointestinal stromal tumors (GISTs) form commonly in the stomach, small intestine, colorectum, and esophagus. Metastatic GIST occurs in up to 50% of patients at presentation. The liver and peritoneal cavity are the most common (93%) metastatic sites; head and neck metastases are extremely rare. This report describes a unique case of a 77-year-old man who was diagnosed with a duodenal GIST that had been completely resected 15 years ago. Eleven years after complete resection, he presented with liver metastases and then received multiple lines of systemic therapy and ablative radiotherapy. In 2015, he presented to our oral and maxillofacial surgery department with a left exophytic maxillary mass that filled the left maxillary sinus. Incisional biopsy confirmed metastatic GIST. Further evaluation revealed extensive metastases in the patient's liver, lungs, spleen, abdominal wall, and lymph nodes. After adequate staging, the patient's condition was deemed palliative, and he was referred to the radiation oncology department for palliative treatment of the symptomatic maxillary lesion. To our knowledge, this is the first reported case of maxillary metastasis from a duodenal GIST. Inclusion of GIST in the differential diagnosis of jaw tumors in patients with nonoral malignancies is recommended. The literature on oral metastasis of GIST is reviewed and discussed in this case report.

Leptomeningeal Carcinomatosis Secondary to a Gastrointestinal Stromal Tumor

A 66-year-old male presented to the emergency department (ED) with altered mental status and concern for stroke. Seven months prior to presentation, the patient was diagnosed with a benign gastrointestinal stromal tumor (GIST), for which he did not receive further workup. Initially, there was a concern for a stroke, however, CT of the brain, CT angiography of the head and neck, and MRI of the brain were negative for any acute abnormalities. Lumbar puncture (LP) revealed a low glucose level with increased protein and white blood cells in the cerebrospinal fluid (CSF). The patient did not display the typical signs and symptoms of meningitis, however, inpatient antibiotic treatment was initiated. The patient continued to deteriorate and repeat LP with cytology was ordered, which revealed malignant cells that were similar to the biopsy of the GIST; our patient was diagnosed with leptomeningeal carcinomatosis (LMC) secondary to the GIST. This case report presents a rare complication of a solid GIST and highlights the need for a high clinical index of suspicion for LMC, including those previously deemed to be benign.

Perirectal Extragastrointestinal Stromal Tumor: An Unusual Presentation

Gastrointestinal stromal tumors (GISTs), even though rare, remain the most common mesenchymal tumors of the gastrointestinal (GI) tract. When GISTs occur outside of the GI tract, they are termed extragastrointestinal stromal tumors (EGISTs). Most GISTs arise from the stomach (50-70%) and small intestine (20-30%). A smaller percentage of these tumors also occurs in the large intestine (5%) and esophagus (2-5%). EGISTs have histopathological and molecular characteristics that are similar to GISTs. However, the precise incidence and tumor behavior of EGISTs are not fully understood. EGISTs have no specific symptoms or radiologic features, and in most cases, the presenting complaint is abdominal pain or discomfort. Yet, they tend to be more aggressive and have a worse prognosis than GISTs. Morphologic diagnosis based on microscopic examination of histological sections is the standard diagnostic procedure for GIST/EGIST. In this patient-centered study, we present a case of EGIST that originated in the anterior perirectal space, an extremely rare location; we also describe the endoscopic approach that was used to biopsy the tumor.

Gastrointestinal stromal tumor: a review of current and emerging therapies

Gastrointestinal stromal tumors (GIST) are rare neoplasms arising from the interstitial cell of Cajal in the gastrointestinal tract. Two thirds of GIST in adult patients have c-Kit mutation and smaller fractions have platelet derived growth factor receptor alpha (PDGFRA) mutation. Surgery is the only curative treatment for localized disease. Imatinib improves survival when used adjuvantly and in advanced disease. Several targeted therapies have also improved survival in GIST patients after progression on imatinib including sunitinib and regorafenib. Recently, United States Federal and Drug Administration (FDA) approved two new tyrosine kinase inhibitors for the treatment of heavily pretreated advanced/unresectable GIST including avapritinib (a selective inhibitor for PDGFRA exon 18 mutation including D842V mutations) and ripretinib (a broad-spectrum kinase inhibitor of c-Kit and PDGFRA). In this article, we will provide a comprehensive review of GIST including the current standard of care treatment and exploring future paradigm shifts in therapy.

Laparoscopic ultrasound guided wedge resection of the stomach: a novel procedure for gastric submucosal tumor

It is essential for the surgery of gastric submucosal tumors to resect the tumor with a negative margin and minimize the incision of the normal stomach wall. We developed a novel procedure for patients with gastric submucosal tumors using a laparoscopic ultrasound probe as a guide to determine the resection line. Since 2014, we have performed the laparoscopic ultrasound-guided wedge resection of the stomach in seven patients. The tumor was localized, and the property of the tumor was clearly identified using a laparoscopic ultrasound probe. As a result, the ideal incision line was determined without intraoperative endoscopy. The stomach wall was perforated along the marking on the planned incision line and the whole layer is subsequently incised along with the tumor. The surgical margins were negative, and there were no obvious injuries of the pseudocapsule, microscopically, in any case. It is possible that the laparoscopic ultrasound-guided wedge resection of the stomach contributes to a simplification of the surgery of gastric submucosal tumors resulting in reduced medical cost while maintaining curability and functional preservation.

Characteristics and prognosis of jejunoileal gastrointestinal stromal tumours (GISTs) in the era of imatinib: a comparative study with gastric GISTs

BACKGROUND

Gastrointestinal stromal tumours (GISTs) located in the jejunum or ileum (JI-GIST) are considered worse prognosis compared to those of gastric (G-GIST) location. It has been suggested that this dogma should be revised. The aim of this study was to describe the characteristics of jejunoileal GISTs and its prognosis and to compare them with G-GISTs in the era of imatinib.

METHODS

We retrospectively reviewed the clinical histories of all the patients diagnosed with GISTs between January 2000 and November 2016: Clinical and pathological data, as recurrence, metastatic state, disease-free survival (DFS) as well as overall survival (OS) rates of patients were reviewed.

RESULTS

JI-GIST patients comprise 29 cases (37.7%). Compared to G-GIST, JI-GIST patients had undergone emergency surgery more frequently (37.9% vs. 10.4%, p = 0.007). According to the NIH-Fletcher classification, the low or very-low risk group represents 17.2% of JI-GISTs as opposed to 37.6% of G-GISTs (p < 0.005). When the AFIP-Miettinen system was used the low or very-low group represented 17.2% of JI-GISTs vs. 58.4% in the G-GISTs group (p < 0.001). Both local recurrence (24.1% vs. 12.5%, p < 0.05) and metastatic rate (34.5% vs. 22.9%, p < 0.05) were higher in the JI-GIST group than in G-GIST. 5- and 10-year DFS and 10-year OS rate were lower for JI-GIST (54.5% and 39.6% vs. 77.2% and 60.8%, and 57.9% vs. 65%, respectively, p < 0.05).

CONCLUSIONS

The observed differences between both groups in DFS and OS rates at long term could be attributed to the effect of imatinib.

Gastrointestinal stromal tumor of the stomach with lymph node metastasis treated by laparoscopic and endoscopic cooperative surgery with lymph node pick-up resection: A case report and literature review

INTRODUCTION

Gastrointestinal stromal tumor of the stomach with lymph node metastasis is a rare condition, and few cases have been treated by gastrectomy and systematic lymph node dissection.

PRESENTATION OF CASE

We report the case of a patient who was treated by local resection with laparoscopic and endoscopic cooperative surgery and lymph node pick-up resection. A 73-year-old woman presented with gastric submucosal tumor and swollen lymph node. The submucosal tumor was 30 mm in size. After surgery, the tumor was confirmed to be a gastrointestinal stromal tumor by immunostaining. No recurrence was noted 36 months following the surgery.

DISCUSSION

Laparoscopic and endoscopic cooperative surgery allows minimal resection because the exact resection margin can be identified. Therefore, endoscopy is a useful aid in the treatment of gastric gastrointestinal stromal tumor. The MIB-1 index of metastatic lymph node was lower than that of a primary lesion; hence, the prognosis might not depend on lymph node metastasis.

CONCLUSION

Laparoscopic and endoscopic cooperative surgery and lymph node pick-up resection were useful and minimally invasive. Systematic lymph node dissection is not a viable option.

Minimally Invasive Resection of Large Gastric Gastrointestinal Stromal Tumors

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) frequently present as a large exophytically growing mass in the stomach, for which open partial gastrectomy is standard of care. The aim of this study was to evaluate the safety and feasibility of minimally invasive gastric resection (MIG) of large (>5 cm) GIST.

METHODS

All patients who underwent MIG for a GIST in the University Medical Center Utrecht between 2011 and 2019 were included. Postoperative course and oncological outcomes were analyzed.

RESULTS

Twenty-two patients with gastric GIST, median size 53 mm [20-175 mm], underwent MIG. In 4 patients, preoperative imatinib was given, aiming for tumor regression. Conversion from laparoscopic to open surgery occurred once (5%). An additional resection was performed in 3 patients (14%). In 2 patients (9%), an intraoperative complication occurred, consisting of tumor rupture in 1 patient (5%), and 6 patients (27%) developed postoperative complications. Median hospital stay was 5 days [3-7 days]. R0 resection was achieved in 96%. In 4 patients, adjuvant treatment was indicated. The median follow-up was 31 months, and 1-, 3- and 5-year disease-free survival were 94, 74 and 74%, respectively. One patient presented with local recurrence 2 years after the index resection.

CONCLUSION

MIG for large GIST up to 17.5 cm in diameter is safe, feasible, and oncologically sound, allowing for a controlled resection and reduced patient morbidity.

Unusual presentation of small bowel GIST: diffuse omental & mesenteric sarcomatosis

Gastrointestinal stromal tumors (GISTs) represent ~1% of gastrointestinal (GI) tract neoplasms. Unusual presentation of a small bowel GIST with diffuse omental and mesenteric implants in a symptomatic patient is reported. CT scan in a 68-years-old woman showed multiple processes with solid density and colliquation areas in the abdominal cavity. At surgery, an uncommon finding of multiple omental and mesenteric secondary implants was evident. The index mass with 40 cm of adjacent small bowel, omentum and all peritoneal lesions were completely removed. Definitive pathology report showed a small bowel GIST with focal areas of necrosis and high mitotic activity (35 mitosis/50 High Power Fields), with multiple metastases on mesentery and omentum. Patient was therefore submitted to adjuvant treatment with Imatinib and a close follow-up program. Small bowel GIST with high mitotic activity may present with diffuse omental and mesenteric peritoneal seedings. Complete surgical clearance remains the mainstay of treatment.

Primary Gastrointestinal Stromal Tumor of the Prostate: Unexpected Guest

Primary mesenchymal lesions of the prostate are exceptionally rare. They comprise 1% of all prostatic neoplasms. Despite its rare location, the diagnosis of primary gastrointestinal stromal tumors (GISTs) of the prostate gland should never be missed. Such a diagnosis can be made after the rolling out of direct extension from adjacent organs, especially the rectum. GIST diagnosis has a clinical impact on patient treatment and clinical outcomes. They harbor a certain KIT activation mutation that responds to pharmacologic therapy inhibitors.

The objective of the current study was to provide a thorough review of GIST arising primarily in the prostate gland along with a comprehensive study of GIST pathogenesis, histologic morphology, immunohistochemistry, and molecular studies’ findings, and their importance in differentiating GIST from other prostate mesenchymal tumors. This will emphasize the role of careful spindle cell lesion diagnosis in the prostate gland that can influence the prognostic stratification of clinical management, future follow-up, and disease outcome.

Thirteen cases were collected after an extensive and detailed review of the English literature through PubMed, Medknow, Google Scholar, as well as personal experience.

The anatomic location of this lesion plays a significant role in the differential diagnosis. It is difficult to establish the accurate primary origin of GIST on core needle tissue biopsy. Thus, clinical, and radiological examinations play a crucial role in rolling out the possibility of rectal GIST secondarily invading and involving the prostate gland.

To conclude, primary prostatic GIST is a rare diagnosis. Extraintestinal, particularly rectal, GIST can clinically and radiologically mimic the impression of the prostatic lesion. Before diagnosing primary prostatic spindle cell lesions, such as solitary fibrous tumor (SFT), inflammatory myofibroblastic tumor (IMT), leiomyoma, leiomyosarcoma, or prostatic stromal tumors, one should include CD117/c-Kit in the workup of a prostatic spindle cell lesion. GIST has distinct pathogenesis, and its diagnosis can have a clinical impact on the patient's management plan and clinical outcome.

Laparoscopic Versus Open Surgery for Gastric Gastrointestinal Stromal Tumors: a Propensity Score Matching Analysis

BACKGROUND

Surgery is the first choice for the treatment of gastric gastrointestinal stromal tumors (GISTs). With the development of new instruments and techniques, the popularity of laparoscopic resection of GISTs has increased rapidly. Previous studies on the advantages of laparoscopic resection over open surgery are generally limited by methodology or data capacity. This study evaluated the efficacy of laparoscopic resection and open surgery in gastric GISTs using the propensity score matching (PSM) method.

METHODS

Between January 2005 and December 2017, 1027 patients were diagnosed with primary GIST at our institution. Among them, 548 patients were enrolled in this study. Standard demographic and clinicopathological data were collected from our database. Selection bias was eliminated using the PSM methods.

RESULTS

After PSM, 256 cases involved in the comparison (128 laparoscopic (LAP) vs. 128 open surgery (OPEN)) were randomly matched (1:1) by age, sex, body mass index, hypertension, diabetes, heart disease, year of surgery, tumor location, tumor size, mitotic rate, and treatment with adjuvant tyrosine kinase inhibitors. The LAP group was superior to the OPEN group in blood loss (χ² = 6.048, P = 0.049), time to first flatus (49.41 ± 7.56 vs. 71.31 ± 4.87 h, P < 0.001), and hospital stay (10.21 ± 6.05 vs. 12.56 ± 5.43 days, P = 0.001). No significant differences were seen in either the relapse-free survival or overall survival between the LAP and OPEN groups. In tumors located in favorable locations, the LAP group showed less blood loss (P = 0.008) and less multivisceral resection (17.8% vs. 5.5%, P = 0.02).

CONCLUSIONS

Laparoscopic resection for gastric GISTs is associated with improved surgical outcomes and postoperative courses and comparable oncological outcomes, regardless of favorable or unfavorable tumor location.

Gastrointestinal Stromal Tumors: A Single Institution Experience of 176 Surgical Patients

Large single-institution series of patients undergoing resection for gastrointestinal stromal tumors (GIST) are lacking. Clinicopathologic characteristics and postoperative outcomes were retrospectively collected and analyzed from patients undergoing resection for GIST from 2002 to 2011. One hundred seventy-six patients were identified; 156 underwent resection of primary nonmetastatic disease. KIT mutations were identified in 131 patients (84.0%). Of the 156 patients with primary disease, the most common site was the stomach (75.6%). Tumors were categorized as very low (24.4%), low (35.9%), intermediate (12.2%), high (24.4%), or unknown (3.2%) risk. Symptomatic patients more often had high risk (35.6 vs 9.8%; P < 0.0001) and larger tumors (7.3 vs 3.0 cm; P < 0.0001). Forty-seven patients (30.1%) underwent laparoscopic resection (LR). Compared with open surgery, LR was performed for smaller tumors (3.8 vs 6.2 cm; P = 0.002). Positive margin rates were similar (4.3% LR vs 10.2% open; P = 0.346). Median follow-up for the 156 patients with primary tumors was 32.9 months; mean overall survival was 120.9 months (median not reached). Of the 20 patients with metastatic GIST (excluded from above analysis), five patients (25.0%) died of disease with a median follow-up of 15.9 months. Most patients with resectable primary GIST have a favorable prognosis. The presence of symptoms directly related to GIST may be associated with a poor prognosis and is likely related to increased tumor size. Laparoscopic resection is well tolerated and does not appear to compromise outcomes in well-selected patients. Highly selected patients with metastatic disease may benefit from resection.

Laparoscopic versus Open Resection for Gastric Gastrointestinal Stromal Tumors: A Meta-analysis

We conducted our meta-analysis to compare outcomes between laparoscopic resection and open resection for gastric gastrointestinal stromal tumors (GISTs) from all published comparative studies in the literature. Databases, including PubMed, Embase, Cochrane Library, Ovid, Web of Science, and CNKI, were searched to identify studies comparing outcomes after laparoscopic resection and open resection for gastric GISTs. The meta-analysis was performed by RevMan 5.1. Eleven comparative studies comprising 495 patients were identified. Patients undergoing laparoscopic resection of gastric GISTs were found to have similar operative time (weighted mean difference [WMD], 2.29; 95% confidence interval [CI], -16.01 to 11.43; P = 0.74) and complications rate (odds ratio [OR], 0.76; 95% CI, 0.36 to 1.58; P = 0.46). Less intraoperative blood loss (WMD, -55.91; 95% CI, -90.26 to -21.56; P = 0.001), earlier passing first flatus (WMD, -0.89, 95% CI, -1.60 to -0.18; P = 0.01), earlier having the first liquid diet (WMD, -1.54; 95% CI, -2.44 to -0.64; P = 0.0008), and shorter hospital stay (WMD, -4.25; 95% CI, -5.63 to -2.88; P < 0.00001) were observed in the laparoscopic resection group. The recurrence rate was higher in the group of open resection compared with the group of laparoscopic resection (OR, 0.26; 95% CI, 0.09 to 0.75; P = 0.01). Laparoscopic resection is safe and efficient in the treatment of patients with gastric GISTs as compared with open resection procedure. Laparoscopic resection may be a preferred treatment for gastric GISTs.

S100A4 expression is associated with poor prognosis in patients with resectable gastrointestinal stromal tumor

S100A4 is particularly associated with the progression and metastasis of numerous human malignancies. This study was designed to examine the clinicopathologic significance of S100A4 in gastrointestinal stromal tumor (GISTs). The level of OPNS100A4 expression in a large cohort of resectable GISTs was evaluated with immunohistochemistry. Its correlation with the clinicopathologic parameters of patients with resectable GISTs was analyzed. A survival analysis was performed to evaluate the prognostic significance of S100A4 expression using Kaplan-Meier method. Results: In 108 patients with resectable GISTs, the most high-risk GISTs had a strong level of S100A4 expression. Strong S100A4 expression was significantly associated with tumor size, mitosis, and recurrence, but not gender and age. Patients with weak S100A4 expression had a relatively longer disease-free survival compared to patients with strong S100A4 expression.Therefore, S100A4 expression is a putative marker for tumor progression and an adverse prognosis in GISTs.