Gastrointestinal Stromal Tumors

Regorafenib exerts an inhibitory effect on the proliferation of human lung fibroblasts by reducing the production of several cytokines in vitro study

BACKGROUND

Pulmonary fibrosis is a disease that leads to respiratory failure and death. There has been little progress in therapeutic strategies for pulmonary fibrosis. There have been several reports on the cytokines associated with pulmonary fibrosis, including IL-6 and TGF-β1. Angiogenesis is one of the most important phenomena in the pathogenesis of pulmonary fibrosis. Previously, we reported the preventive effects of thalidomide against pulmonary fibrosis via the inhibition of neovascularization by angiogenic factors such as VEGF. Regorafenib is a multikinase inhibitor, which inhibits tyrosine kinase receptors such as VEGFR1-3 and TIE2. In the clinical setting, regorafenib has been widely used for anti-cancer therapy for metastatic colorectal cancer. In this study, we examined the preventive effects of regorafenib against pulmonary fibrosis.

METHODS

We investigated whether regorafenib had an inhibitory effect on the proliferation, viability, and production of several cytokines in lung fibroblasts.

RESULTS

We demonstrated an inhibitory effect of regorafenib on the proliferation and viability of lung fibroblasts. Moreover, regorafenib reduced the production of several cytokines associated with the pathogenesis of pulmonary fibrosis, including IL-6, VEGF and TGF- β1, and collagen synthesis from lung fibroblasts.

CONCLUSIONS

These data suggest that regorafenib may have potential clinical applications in the prevention of pulmonary fibrosis.

Preclinical study of microphthalmia-associated transcription factor inhibitor ML329 in gastrointestinal stromal tumor growth

Gastrointestinal stromal tumors (GISTs) comprise about 80% of mesenchymal neoplasms in the gastrointestinal tract. Although imatinib mesylate is the preferred treatment, the development of drug resistance highlights the need for novel therapeutic strategies. Recently, we have identified the microphthalmia-associated transcription factor (MITF) as a critical player in pro-survival signaling and tumor growth. This study investigates the effects of MITF inhibition using ML329, an MITF pathway inhibitor, on GIST cell viability in vitro and in NMRI-nu/nu mouse xenograft models. ML329 suppresses growth in imatinib-sensitive (GIST-T1) and -resistant (GIST 430/654) cell lines, impairs MITF targets such as BCL2 and CDK2, and induces S-G2/M cell-cycle arrest. In vivo, ML329 is well tolerated and significantly reduces tumor growth in established imatinib-sensitive and -resistant GIST models. These findings underscore the importance of MITF in GIST growth and support its inhibition as a promising therapeutic approach.

Effects of first‑line therapies in patients with locally advanced gastrointestinal stromal tumors with KIT and PDGFRα gene mutations: A single‑center study

Curative resection is typically recommended for treating gastrointestinal stromal tumors (GISTs). Exceptions are made for locally advanced GISTs (LAGISTs) where radical resection may be impossible. First-line imatinib therapy can be employed to treat GISTs harboring mutations in the tyrosine-protein kinase KIT (KIT) and platelet-derived growth factor receptor α (PDGFRα) genes to reduce the tumor size to resectable levels and minimize surgical risks. The present study investigated the treatment outcomes of patients with LAGISTs with different KIT and PDGFRα gene mutations who received first-line imatinib therapy. A total of 37 patients with LAGISTs who underwent first-line imatinib treatment were included, and the median follow-up period was 41 months. Treatment regimens included imatinib, with subsequent therapies, such as sunitinib and regorafenib, administered upon imatinib failure. The genetic profiles of KIT and PDGFRα were analyzed. Of the 37 patients, 24 (64.9%) successfully underwent curative resection. The median progression-free survival (PFS) was 36 months and the median overall survival (OS) was 41 months. Patients presented with tumors with various genetic mutations, which differentially affected their PFS and OS and adverse events were typically manageable. However, the gene mutation status was not significantly associated with treatment response or surgical resectability (both P>0.05). The present study elucidated the effects of first-line therapy on LAGISTs with genetic mutations, underscoring the effectiveness of imatinib treatment and the value of continual patient monitoring. Additional studies with long-term follow-up are required to evaluate treatment outcomes.

Regulatory roles of non-coding RNAs in programmed cell death pathways and drug resistance in gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract, primarily driven by KIT or PDGFRA mutations. Programmed cell death (PCD), including apoptosis, autophagy, and ferroptosis, plays a crucial role in GIST pathogenesis, progression, and treatment response. Non-coding RNAs (ncRNAs) have emerged as key regulators of PCD pathways, influencing GIST proliferation, metastasis, and drug resistance, particularly in response to tyrosine kinase inhibitors (TKIs) such as imatinib. Apoptosis suppression is strongly associated with poor prognosis, while autophagy contributes to tumor dormancy and TKI resistance. Ferroptosis, a novel iron-dependent cell death pathway, represents a promising therapeutic target. Recent evidence suggests that ncRNAs modulate these PCD pathways through interactions with key molecular regulators such as miR-494, miR-30a, and lncRNAs, which affect signaling networks including PI3K/AKT, MAPK, and mTOR. Furthermore, ncRNAs have mediated secondary resistance to imatinib by promoting autophagic flux and altering ferroptosis sensitivity. Understanding the molecular interplay between ncRNAs and PCD in GIST provides novel insights into disease mechanisms and offers potential therapeutic strategies to overcome drug resistance. Targeting ncRNA-mediated regulation of apoptosis, autophagy, and ferroptosis may enhance treatment efficacy and improve patient outcomes. Future research should focus on elucidating the mechanistic roles of ncRNAs in PCD pathways to develop innovative diagnostic and therapeutic approaches for GIST.

Clinical characteristics of gastrointestinal stromal tumors with lymph node metastasis: a retrospective single-center study

BACKGROUND

Lymph node metastasis (LNM) of gastrointestinal stromal tumors (GISTs) rarely occurs, and lymphadenectomy is not routinely performed in GIST resection. To date, the relevant characteristics and prognosis of GIST patients with LNM are not well known.

METHODS

From January 2010 to December 2021, GIST patients who underwent lymph node resection were enrolled from a GIST referral center. All patients were divided into either the LN- group (GISTs without LNM) or the LN+ group (GISTs with LNM). The clinicopathological features and follow-up data were analyzed. Propensity score matching (PSM) was conducted to reduce bias caused by confounders.

RESULTS

Out of 1024 surgical patients, 198 patients (age, 52.23 ± 13.54 years; 56.6% males) underwent GIST resection with lymph node dissection for lymphadenopathy, and 17 patients had lymph node metastases (17/1024, 1.66%; 17/198, 8.59%). The LN+ group had a higher mitotic count (p = 0.012) and a higher proportion of distant metastasis (p < 0.001) than the LN- group. After PSM, 28 patients were included (18 in LN- group and 10 in LN+ group). The LN- group had both longer postoperative progression-free survival (PFS, not reached vs. 15.0 months, p = 0.002) and overall survival (OS) than the LN+ group, but the difference in OS was not statistically significant (not reached vs. 35.0 months, p = 0.069).

CONCLUSIONS

The rate of LNM in GISTs is low. LNM may be a less common form of distant metastasis. Moreover, GIST with LNM has an unfavorable prognosis. Further studies are warranted to identify GISTs with lymph node involvement and the potential involved mechanism.

Using body composition to predict treatment-related adverse events and disease-free survival in patients with gastrointestinal stromal tumors treated with imatinib: a retrospective cohort study

Background

Imatinib (IM) is the primary treatment for Gastrointestinal stromal tumor (GIST), but it faces significant challenges with resistance and a high incidence of adverse events. This study aims to assess the predictive value of baseline body composition parameters on treatment-related adverse events and disease-free survival (DFS) in GIST patients treated with imatinib.

Materials and Methods

A single-center retrospective analysis was conducted on 107 moderate or high-risk stratification GIST patients diagnosed from 2014 to 2020 at the First Affiliated Hospital of Nanjing Medical University. Body composition parameters, including skeletal muscle index (SMI), myosteatosis, cachexia index (CXI), and Fat-Free Mass (FFM), etc. were obtained using abdominal CT images and clinical data. Logistic and COX regression models were used to analyze the relationship between these indicators and treatment-related adverse events and DFS.

Results

Multivariate analysis revealed that myosteatosis (OR=7.640, P<0.001) and drug dose (OR=1.349, P=0.010) were independent risk factors for adverse events, while a higher CXI (OR=0.983, P=0.017) was protective. Additionally, LAMA/SMA% (OR=1.072, P=0.028) was identified as an independent risk factor for dose-limiting toxicity (DLT). Independent predictors of DFS included sarcopenia (HR=3.067, P=0.013), myosteatosis (HR=6.985, P=0.024), risk stratification (HR=9.562, high-risk vs. moderate-risk, P=0.003), and C-KIT mutation (HR=3.615, C-KIT exon 9 mutation vs. 11, P=0.013).

Conclusions

Baseline body composition parameters, particularly myosteatosis, effectively predict the adverse events and DFS in patients taking imatinib. Personalized treatment, such as targeted nutritional and exercise interventions, and close monitoring of patients with myosteatosis or sarcopenia can enhance compliance and improve survival rates.

A rare unifocal gastric gastrointestinal stromal tumor in a young NF1 patient: A case report

INTRODUCTION AND IMPORTANCE

Gastrointestinal stromal tumors (GISTs) are the most prevalent mesenchymal neoplasms of the gastrointestinal tract, predominantly associated with mutations in the KIT and PDGFRA genes. Neurofibromatosis type 1 (NF1) increases the risk of developing GISTs, particularly in younger individuals, and often presents with atypical features.

CASE PRESENTATION

A 16-year-old female with a known diagnosis of NF1 presented with severe anemia, hematemesis, and melena. Physical examination revealed multiple café-au-lait spots and cutaneous nodular masses. A contrast-enhanced CT scan showed a large mass arising from the stomach's greater curvature, consistent with GIST. The patient underwent a sleeve gastrectomy, and histopathological evaluation confirmed high-grade spindle cell GIST. Immunohistochemistry was positive for CD117, CD34, and DOG-1. Postoperative PET-CT showed no residual disease.

CLINICAL DISCUSSION

GIST in NF1 patients typically presents with a multifocal pattern, but our patient exhibited a rare unifocal GIST in the stomach. The diagnosis was complicated by atypical presentation and required multimodal imaging and histopathological confirmation. NF1-associated GISTs generally lack KIT and PDGFRA mutations, rendering targeted therapies like imatinib ineffective, emphasizing surgical management as the primary treatment.

CONCLUSION

This case highlights the unique clinical and pathological characteristics of NF1-associated GISTs, stressing the need for vigilant assessment in NF1 patients with gastrointestinal symptoms.

Recent Advances in Succinate Dehydrogenase Deficient Gastrointestinal Stromal Tumor Systemic Therapies

OPINION STATEMENT

Gastrointestinal stromal tumors (GIST) are the most common gastrointestinal soft tissue sarcomas, with an incidence of about 15 cases per million person-years. Approximately 15% of GIST develop due to succinate dehydrogenase deficiency (SDH-Def), and such tumors do not respond well to the tyrosine kinase inhibitors (TKIs) used to treat other GIST. Due to its indolent nature SDH-Def GIST can often be surveilled if asymptomatic. In our current practice we typically treat advanced symptomatic SDH-Def GIST with the anti-angiogenic TKIs, sequentially treating with sunitinib, regorafenib and pazopanib. This practice is based on limited data. This systematic review provides an update on new data (12/21/2021 to 9/26/2024) for systemic treatment of SDH-Def GIST, both with agents generally used to treat other GIST subtypes and with agents approved in other malignancies. Olverembatinib and rogaratinib have shown promising activity in pre-clinical models and small SDH-Def GIST cohorts. Other agents whose benefits are explored here include the immune checkpoint inhibitors (ICI) ipilimumab and nivolumab and temozolomide, whether as monotherapy or in combination with INBRX-109 (a pro-apoptotic antibody) or olaparib. Additional research into TKI agents with anti-vascular endothelial growth factor receptor (VEGFR) and anti-fibroblast growth factor receptor (FGFR) activity in this clinical setting is needed. Patients with SDH-Def will benefit more broadly from ongoing explorations of treatments with alternative mechanisms of action, especially those that exploit cellular pathways involved in SDH-Def GIST tumorigenesis.

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).

Gastric gastrointestinal stromal tumor in a patient with neurofibromatosis type I presenting with anemia: A case report

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are caused by mutations in the KIT and platelet derived growth factor receptor alpha genes in approximately 90% of cases. A minority of wild-type GISTs are associated with neurofibromatosis type 1 (NF1), an autosomal dominant genetic disease resulting from pathogenic mutations in the NF1 gene, which encodes the neurofibromin protein. NF1 patients often exhibit multi-system involvement, with café-au-lait macules and neurofibromas being characteristic symptoms. GISTs are a rare complication of NF1, with the tumors most frequently occurring in the small intestine (90% of cases), while occurrences in the stomach are rare.

CASE SUMMARY

A 51-year-old woman presented to the emergency department with complaints of dizziness, fatigue, chest tightness, and dark stools. Initial examination revealed a red blood cell count of 1.99 × 1012/L and a hemoglobin level of 43 g/L. She underwent blood transfusions and fluid replacement to stabilize her condition. Further investigations identified typical café-au-lait macules on her trunk, limbs, and face, along with neurofibromas. Endoscopy showed coffee-colored fluid in the gastric cavity, a large submucosal elevation with an exudative covering, and ulcer formation on the gastric fundus. Exploratory laparoscopy confirmed the tumor's origin in the gastric fundus, and resection of the giant GIST was performed. Pathological analysis revealed a necrotic GIST measuring 18 cm × 14 cm, classified as high-risk, with approximately 5 mitotic figures per 10 high-power fields and no tumor at the margins. Immunohistochemistry results were CD117 (+), delay of germination 1 (+), CD34 (+), and succinate dehydrogenase complex iron sulfur subunit B intact expression. Genetic testing using next-generation sequencing confirmed an NF1 gene mutation. The patient underwent successful tumor resection and was discharged home with postoperative regorafenib therapy. A follow-up at one year showed no recurrence.

CONCLUSION

Given the diversity of clinical symptoms associated with NF1 and the complexity of NF1-related GISTs, surgical resection with complete tumor removal remains the preferred treatment option. However, the absence of a standardized treatment protocol for adjuvant therapy presents numerous challenges for clinicians.

Multiple small bowel GIST as GI manifestation of neurofibromatosis type I: A case report

Neurofibromatosis type 1 (NF1) is characterized by café-au-lait patches on the skin and the presence of neurofibromas. Gastrointestinal stromal tumor (GIST) is the most common GI tumour in NF1 patients. In NF1-associated GIST, KIT and PDGFRA mutations are frequently absent and imatinib is ineffective. Surgical resection is first-line treatment. A 58-year-old woman present with dyspepsia symptoms and physical examination was notable for multiple café-au-lait patches and multiple subcutaneous nodular masses of the skin of the face, trunk, and limbs. Abdomininoplevic CT shows multiple different size avidly enhancing small bowel mass. The patient underwent laparotomy and resection with jejenu-jejunal anastomosis was done with smooth post op condition. Histopathology shows Grade I GIST with score 4+ immune reactivity for CD117. It is typically difficult to make a conclusive preoperative diagnosis of GISTs. Computed tomography of the abdomen should be done in Neurofibromatosis type 1 Patients with gastrointestinal symptoms as GISTs may be the cause of these symptoms. Surgical resection may also be performed for both diagnosis and treatment. The objective of this case repot is to describe the radiological feature of multiple GIST in elder NF1 patient in resource limited setup.

Racial Disparities and Trends in Outcomes of Patients with Gastrointestinal Stromal Tumors

BACKGROUND

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. However, there are limited studies on the latest survival trends and the impact of racial disparities on GIST patients' outcomes.

METHODS

We obtained 12,808 GIST patients between 2001 and 2020 from the Surveillance, Epidemiology, and End Results (SEER) database in 17 original sites. Analysis utilizing the Kaplan-Meier method explored survival disparities and Cox regression was employed to assess the impact of prognostic factors.

RESULTS

Our study revealed an increase in the GIST incidence per 100,000 people over the past two decades, along with a rise in relative survival rate (RSR). Age, gender, social groups, tumor site, size, stage, socioeconomic status, marital status, surgery, and systemic therapy are prognostic factors. Subgroup analysis indicated higher incidence and poorer survival trends among Non-Hispanic Blacks (NHB) (Incidence, 1.88 per 100,000 people; 120 Mo RSR, 61.6%, 2001 to 2020). Colonic GIST has the worst prognosis among different locations, while rectal and anal GIST has the best. Within these groups, Non-Hispanic White (NHW) with colonic GIST have the poorest prognosis (HR, 2.032; 95% CI, 1.476-2.798), whereas NHB with rectal and anal GIST have the best prognosis.

CONCLUSION

The incidence and RSR of GIST both increased during 2001-2020. NHW with colonic GIST showed poorer survival, while NHB with rectal and anal GIST revealed better survival, highlighting the importance of targeted clinical management for GIST.

Transcoccygeal resection for a presacral GIST of the distal rectum

Gastrointestinal stromal tumours (GISTs) of the rectum are rare and comprise about 5% of all GISTs. Workup includes biopsy with immunohistochemistry analysis. Surgical excision is the standard treatment, although tyrosine kinase inhibitors, particularly imatinib, are known to be useful in the neoadjuvant and adjuvant settings. We present a case of a woman in her 70s who was diagnosed with distal rectal GIST. MRI revealed the tumour to be located within the presacral space. She underwent core needle biopsy with immunohistochemistry confirming KIT-positive GIST. The patient received neoadjuvant imatinib therapy, followed by surgical excision via the transcoccygeal approach (Kraske procedure). She recovered appropriately and went on to receive adjuvant imatinib therapy. We describe the progression of this patient's care and review various pertinent therapies for distal rectal GIST, highlighting the transcoccygeal resection as a safe and effective approach.

Liquid chromatography-tandem mass spectrometry for the quantification of ripretinib and its metabolites DP-5439 in human plasma

Background

Ripretinib, a broad-spectrum tyrosine kinase inhibitor, has been approved for the treatment of advanced gastrointestinal stromal tumors in adult patients. Clinical studies have shown that higher in vivo exposure of ripretinib correlates with improved efficacy, highlighting the potential clinical significance of therapeutic drug monitoring. In this study, a simple and stable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was attempted to be established and validated for pharmacokinetic studies of ripretinib and its metabolite DP-5439 and therapeutic drug monitoring in human plasma.

Method

Ripretinib and DP-5439 were separated by chromatography using a Thermofisher Hypersil GOLDTM C18 HPLC column. The mobile phase for gradient elution is composed of 0.1% formic acid in water and acetonitrile. Multiple reaction monitoring was implemented along with electrospray ionization positive mode for detection. The ion pairs of ripretinib, DP-5439 and internal standard D8-ripretinib were m/z 510.1→m/z 417, m/z 496.11→m/z 402.9 and m/z 518.15→m/z 420, respectively. Plasma samples from ripretinib-treated patients of our hospital were collected for pharmacokinetic analysis.

Results

Ripretinib and DP-5439 demonstrated a strong linear relationship over 10-5,000 μg/L (R 2 > 0.99). Accuracy, precision, specificity, recoveries, matrix effect, stability, and dilution effect were all validated and found to meet the required criteria. Following validation, the method was utilized to determine plasma samples from patients treated with ripretinib. The median steady-state trough concentrations (Cmin, range) were 398.50 (66.98 ∼ 1,458.91) μg/L for ripretinib and 654.74 (30.71 ∼ 1,522.48) μg/L for DP-5439, with a total median concentration of 1,129.46 (140.95 ∼ 2,981.39) μg/L in patients receiving ripretinib at 150 mg once daily. Meanwhile, using the established methods, the study conducted pharmacokinetics studies on four patients with ripretinib and DP-5439.

Conclusion

This study developed and validated a robust LC-MS/MS method for determining ripretinib and its metabolite DP-5439 in human plasma. Furthermore, the practicality of this method in clinical sample analysis was demonstrated. This approach can serve as an effective tool for the pharmacokinetics analysis and therapeutic drug monitoring in patients treated with ripretinib.

Identifying subtle differences : a radiomics model assessment for gastric schwannomas and gastrointestinal stromal tumors across risk grades

Objective

This study aims to develop and validate an enhanced computed tomography (CT)-based radiomics model to differentiate gastric schwannomas (GS) from gastrointestinal stromal tumors (GIST) across various risk categories.

Methods

This retrospective analysis was conducted on 26 GS and 82 GIST cases, all confirmed by postoperative pathology. Data was divided into training and validation cohorts at a 7:3 ratio. We collected patient demographics, clinical presentations, and detailed CT imaging characteristics. Through univariable and multivariable logistic regression analyses, we identified independent predictors for discriminating between GS and GIST, facilitating the construction of a conventional model. Radiomic features were extracted and refined through manual 3D segmentation of venous phase thin-slice images to develop a radiomics model. Subsequently, we constructed a comprehensive combined model by integrating selected clinical and radiomics indicators. The diagnostic performances of all models in differentiating GS from GIST and stratifying GISTs according to malignancy risk were evaluated.

Results

We identified several key independent variables distinguishing GS from GIST, including tumor location, cystic changes, degree of enhancement in arterial phase, and enhancement uniformity. The conventional model achieved AUCs of 0.939 and 0.869 in the training and validation cohort, respectively. Conversely, the radiomics model, predicated on eight pivotal radiomics features, demonstrated AUCs of 0.949 and 0.839. The combined model, incorporating tumor location, degree of enhancement in arterial phase, enhancement uniformity, and a radiomics model derived rad-score, significantly outperformed the traditional approach, achieving AUCs of 0.989 and 0.964 in the respective cohorts. The combined model showed superior diagnostic accuracy in distinguishing GS from GIST, as well as GS from high or low malignancy potential GISTs, as evidenced by IDI values of 0.2538, 0.2418, and 0.2749 (P<0.05 for all).

Conclusion

The combined model based on CT imaging features and radiomics features presents a promising non-invasive approach for accurate preoperative differentiation between gastric schwannomas and gastrointestinal stromal tumors.

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.

The benefit of surgery during systematic therapy for gastrointestinal stromal tumor liver metastasis: a SEER-based retrospective study

Background

The liver is the most common site of gastrointestinal stromal tumor (GIST) metastasis. Most patients who develop metastases gradually develop multiline drug resistance during long-term systematic treatment. We aimed to evaluate the benefit of surgery during the systematic treatment of GIST liver metastases.

Methods

Data on GISTs with liver metastasis were retrieved from the Surveillance, Epidemiology, and End Results database. This study included 607 patients, of whom 380 patients were treated with chemotherapy alone (Chemo group) and 227 patients underwent surgery in addition to chemotherapy (Chemo&Surg group). The primary outcomes were cancer-specific survival (CSS) and overall survival (OS). Propensity score matching (PSM) was performed to balance the baseline factors.

Results

According to the multivariate analysis, surgery benefitted both CSS and OS (P < 0.001). After PSM, surgical resection still showed significant benefits in terms of both CSS and OS (P < 0.001). Surgery combined with chemotherapy increased the median CSS by at least 63 months and the median OS by at least 76 months. Subgroup analysis of the Chemo&Surg group revealed that the timing of surgery was not an independent influencing factor for either CSS or OS.

Conclusions

We found that performing additional surgery, in addition to systematic therapy, for GIST liver metastasis resulted in improved CSS and OS. These benefits were not affected by the timing of surgery during systemic treatment.

True Mitotic Count Prediction in Gastrointestinal Stromal Tumors: Bayesian Network Model and PROMETheus (Preoperative Mitosis Estimator Tool) Application Development

BACKGROUND

Gastrointestinal stromal tumors (GISTs) present a complex clinical landscape, where precise preoperative risk assessment plays a pivotal role in guiding therapeutic decisions. Conventional methods for evaluating mitotic count, such as biopsy-based assessments, encounter challenges stemming from tumor heterogeneity and sampling biases, thereby underscoring the urgent need for innovative approaches to enhance prognostic accuracy.

OBJECTIVE

The primary objective of this study was to develop a robust and reliable computational tool, PROMETheus (Preoperative Mitosis Estimator Tool), aimed at refining patient stratification through the precise estimation of mitotic count in GISTs.

METHODS

Using advanced Bayesian network methodologies, we constructed a directed acyclic graph (DAG) integrating pertinent clinicopathological variables essential for accurate mitotic count prediction on the surgical specimen. Key parameters identified and incorporated into the model encompassed tumor size, location, mitotic count from biopsy specimens, surface area evaluated during biopsy, and tumor response to therapy, when applicable. Rigorous testing procedures, including prior predictive simulations, validation utilizing synthetic data sets were employed. Finally, the model was trained on a comprehensive cohort of real-world GIST cases (n=80), drawn from the repository of the Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Humanitas Research Hospital, with a total of 160 cases analyzed.

RESULTS

Our computational model exhibited excellent diagnostic performance on synthetic data. Different model architecture were selected based on lower deviance and robust out-of-sample predictive capabilities. Posterior predictive checks (retrodiction) further corroborated the model's accuracy. Subsequently, PROMETheus was developed. This is an intuitive tool that dynamically computes predicted mitotic count and risk assessment on surgical specimens based on tumor-specific attributes, including size, location, surface area, and biopsy-derived mitotic count, using posterior probabilities derived from the model.

CONCLUSIONS

The deployment of PROMETheus represents a potential advancement in preoperative risk stratification for GISTs, offering clinicians a precise and reliable means to anticipate mitotic counts on surgical specimens and a solid base to stratify patients for clinical studies. By facilitating tailored therapeutic strategies, this innovative tool is poised to revolutionize clinical decision-making paradigms, ultimately translating into improved patient outcomes and enhanced prognostic precision in the management of GISTs.

Multifocal Small Bowel Gastrointestinal Stromal Tumor (GIST): A Case Report

Gastrointestinal stromal tumours, also known as GIST, are a rare subset of soft tissue sarcomas. They are the most common mesenchymal neoplasms of the GI tract and can be found multifocal intra-operatively. We present a 44-year-old male patient who presented with vague upper abdominal pain of one-week duration associated with non-bilious vomiting. His CT abdomen with IV contrast revealed a non-enhancing intraperitoneal mass, which displaced the small bowel and mesentery; however, there was no obstruction or strangulation. A CT-guided biopsy was done and showed a low-grade gastrointestinal stromal tumor (GIST). Interestingly, during diagnostic laparoscopy, in addition to the large serosal ileal mass, he had multiple smaller lesions throughout the small bowel. He underwent resection of all the masses. He made an excellent recovery and was discharged home on postoperative day three. Small bowel GIST can rarely present as multiple lesions. Examination of all bowels during surgery is mandatory.

Novel antibody-drug conjugates based on DXd-ADC technology

In recent years, antibody-drug conjugate (ADC) technology, which uses monoclonal antibodies (mAbs) to specifically deliver effective cytotoxic payloads to tumor cells, has become a promising method of tumor targeted therapy. ADCs are a powerful class of biopharmaceuticals that link antibodies targeting specific antigens and small molecule drugs with potent cytotoxicity via a linker, thus enabling selective destruction of cancer cells while minimizing systemic toxicity. DXd is a topoisomerase I inhibitor that induces DNA damage leading to cell cycle arrest, making it an option for ADC payloads. The DXd-ADC technology, developed by Daiichi Sankyo, is a cutting-edge platform that produces a new generation of ADCs with improved therapeutic metrics and has shown significant therapeutic potential in various types of cancer. This review provides a comprehensive assessment of drugs developed with DXd-ADC technology, with a focus on mechanisms of action, pharmacokinetics studies, preclinical data, and clinical outcomes for DS-8201a, U3-1402, DS-1062a, DS-7300a, DS-6157a, and DS-6000a. By integrating existing data, we aim to provide valuable insights into the current therapeutic status and future prospects of these novel agents.

Comprehensive Genomic Assessment of Advanced-Stage GI Stromal Tumors Using the Japanese National Center for Cancer Genomics and Advanced Therapeutics Database

PURPOSE

Clinical utility of comprehensive genomic profiling (CGP) for precision medicine has become evident. Although there are several reports on the genomic landscape of GI stromal tumors (GISTs), large-scale data specific to GIST are limited, especially in Asia. Additionally, the applicability of molecular-targeted agents identified using CGP has not been extensively examined. We investigated the status of genomic alterations in Japanese patients with advanced GISTs using the National Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database to identify novel treatment strategies and drug development.

MATERIALS AND METHODS

We retrospectively reviewed the clinical and CGP data of patients with advanced-stage GIST registered in the C-CAT database to assess the genomic landscape and potential actionable alterations.

RESULTS

Data from 144 patients were reviewed. Oncogenic alterations were detected frequently in KIT (78%), CDKN2A (37%), CDKN2B (29%), RB1 (11%), STK11 (10%), TP53 (9%), PDGFRA (6%), and SDHB (6%). Loss of CDKN2A/CDKN2B was only observed in KIT/PDGFRA-mutated GISTs, while alterations in SDHA/SDHB were only detected in KIT/PDGFRA wild-type GISTs. Among 119 KIT/PDGFRA-mutated GISTs, 95 (80%) had oncogenic genomic alterations and 29 (24%) had actionable alterations, excluding KIT and PDGFRA. However, among 25 KIT/PDGFRA wild-type GISTs, 22 (88%) had oncogenic alterations and 11 (44%) had actionable alterations. Representative candidate drugs for genome-matched therapies in KIT/PDGFRA-mutated and wild-type GISTs were as follows: pembrolizumab for tumor mutation burden-high in one and two patients, respectively; poly-adenosine diphosphate ribose polymerase inhibitors for alterations related to homologous recombination deficiency in 12 and one patient, respectively; NTRK inhibitor for ETV6-NTRK3 fusion in one with KIT/PDGFRA wild-type GIST; and human epidermal growth factor receptor 2-antibody-drug conjugate in one with KIT/PDGFRA-mutated GIST.

CONCLUSION

This study highlights the genomic landscape of advanced GISTs and the important role of CGP in identifying rational molecular-targeted therapeutic options.

circ_SMA4 promotes gastrointestinal stromal tumors malignant progression by sponging miR-494-3p/KIT axis and activating JAK/STAT pathway

Recent evidence has demonstrated that abnormal expression and regulation of circular RNA (circRNAs) are implicated in the development and progression of various tumors. The aim of this study was to investigate the effects of circ_SMA4 in Gastrointestinal Stromal Tumors (GISTs) malignant progression. Human circRNAs microarray analysis was conducted to identify differentially expressed (DE) circRNAs in GISTs. The effect of circ_SMA4 on cell proliferation, invasion, migration, and apoptosis was assessed in both in vitro and in vivo settings. Dual-luciferase reporter assay, RT-qPCR, Western-blot, and rescue assay were employed to confirm the interaction between circ_SMA4/miR-494-3p/ KIT axis. The results revealed that circ_SMA4 was significantly upregulated in GISTs, and exhibited high diagnostic efficiency with an AUC of 0.9824 (P < 0.01). circ_SMA4 promoted cell proliferation, invasion, migration, while inhibiting apoptosis in GISTs cells, both in vitro and in vivo. Silencing circ_SMA4 partially inhibited GISTs malignant progression. Additionally, circ_SMA4 acted as a competing endogenous RNA (ceRNA) by targeting miR-494-3p, and KIT was identified as a functional gene for miR-494-3p in GISTs. Furthermore, the results confirmed that circ_SMA4/miR-494-3p/ KIT axis plays a role in activating the JAK/STAT signaling pathway in GISTs. Therefore, for the first time, we have identified and emphasized that circ_SMA4 is significantly upregulated and plays an oncogenic role in GISTs by sponging miR-494-3p to activate the KIT/JAK/STAT pathway. These findings underscore circ_SMA4 may serve as a novel diagnostic biomarker and therapeutic target for GISTs.

Demographic Trends, Co-Alterations, and Imatinib Resistance across Genomic Variants in Gastrointestinal Stromal Tumors: An AACR Project GENIE Analysis

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal tract, the treatment of which represents a significant breakthrough in targeted cancer therapy. Given its overall rare nature, genomic differences and clinical implications between demographic groups have not been previously investigated.

METHODS

Anonymized demographic, clinical, and genomic data from 1,559 GIST patients in the American Association for Cancer Research Project GENIE database were analyzed using cBioPortal and custom Python scripts. Data on patient demographics, genomic alterations, and co-occurrence genetic alerations were collected and classified according to clinical implications using the OncoKB database. χ2 tests for differences in genomic alterations were used across various demographic factors and mutual exclusivity analysis was employed to identify co-mutation patterns.

RESULTS

Male patients demonstrated higher incidence of PDGFRA mutation (14.56% vs. 8.05%; p < 0.001), while female patients had higher likelihood of NF1 mutations (7.46% vs. 3.23%; p = 0.001). Asian patients had higher alteration rates at KIT (85.59%; p = 0.002). Co-occurrence analysis revealed KIT alterations frequently co-occurred with CDKN2A (q < 0.001), MTAP (q = 0.045), and PTEN (q = 0.056), while there was mutual exclusivity with PDGFRA (q < 0.001), NF1 (q < 0.001), and BRAF (q = 0.015). CDKN2A alterations co-occurred with MTAP (q < 0.001) and PIK3CA (q = 0.015), while being mutually exclusive with TP53 (q = 0.002) and NF1 (q = 0.007). Trends were similar among patients who had received no prior medical treatment. Imatinib-resistant mutations were more common among male patients (25.6% vs. 18.9%; p = 0.0056) and individuals under 55 (27.3% vs. 20.9%; p = 0.0228). Among patients with imatinib-resistant mutations, 77.78% had sunitinib resistance, while 70.25% maintained sensitivity to ripretinib.

CONCLUSION

Sex and race/ethnic differences in genomic alterations, as well as co-mutations, were prevalent among patients with GIST. Variations in mutational profiles highlight the importance of distinct genetic drivers that may be targeted to treat different patient populations.

Two different mutational types of familial gastrointestinal stromal tumors: Two case reports

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract, and cases of GISTs tend to be of the disseminated type, with a global incidence of 10 to 15 cases/million each year. The rarer familial GISTs, which often represent a population, differ in screening, diagnosis, and treatment. Familial GISTs include primary familial GISTs with predominantly KIT/PDGFRA mutations and wild-type GISTs. However, whether the same genetic family has different phenotypes has not been reported.

CASE SUMMARY

We report two cases of rare GISTs in the same family: A male patient with the V561D mutation in exon 12 of the PDGFRA gene, who has been taking the targeted drug imatinib since undergoing surgery, and a female patient diagnosed with wild-type GIST, who has been taking imatinib for 3 years since undergoing surgery. The favorable prognosis of these patients during the 7-year follow-up period validates the accuracy of our treatment strategy, and we have refined the entire process of diagnosis and treatment of familial GISTs in order to better manage this rare familial disease.

CONCLUSION

Different mutation types of familial GISTs in the same family are very rare, thus it is very important to make the correct diagnosis and treatment strategies according to the results of molecular detection for the management of familial GISTs.

Utilization of neoadjuvant therapy for localized gastric gastrointestinal stromal tumors and the association with survival

BACKGROUND

For gastric gastrointestinal stromal tumors (GISTs), neoadjuvant imatinib is most often reserved for tumors near the gastroesophageal junction, multivisceral involvement, or limited metastatic disease. Whether localized gastric GISTs benefit from neoadjuvant therapy (NAT) remains unknown. We sought to examine factors associated with NAT utilization for localized gastric GISTs and evaluate implications on survival.

METHODS

The National Cancer Database identified patients with localized gastric GISTs treated with NAT (2010-2020), excluding tumors extending beyond the gastric wall, located in the cardia, or with metastatic disease. Multivariable logistic regression assessed characteristics of NAT use. After 1:1 propensity score matching, Kaplan-Meier methods and multivariable Cox regression assessed overall survival (OS).

RESULTS

Of 7203 patients, 762 (10.6%) received NAT followed by resection. On multivariable analysis, increasing tumor size was associated with NAT use (<2.0 cm vs 2.0-5.0 cm [odds ratio {OR}, 2.03; 95% CI, 1.19-3.47; P = .010] vs >5 cm [OR, 16.87; 95% CI, 10.02-28.40; P < .001]). After propensity score matching, 1506 patients remained. Median OS for NAT was 46.0 months vs 43.0 months for resection (P = .059), which was independently predictive of improved survival on multivariable analysis (hazard ratio [HR], 0.89; 95% CI, 0.80-0.99; P = .041). Subgroup analysis by tumor size showed no survival differences for tumors <2.0 cm or from 2.0 to 5.0 cm. Median OS was higher for tumors > 5.0 cm treated with NAT (NAT, 45.4 months [IQR, 29.5-65.9] vs upfront resection, 42.3 months [IQR 26.9-62.8]) and associated with improved survival on multivariable analysis (HR, 0.88; 95% CI, 0.78-0.99; P = .040).

CONCLUSION

Although patients who received NAT had improved survival, this was primarily due to tumors >5.0 cm. Expanding NAT selection criteria to include localized gastric GISTs >5.0 cm may improve outcomes and warrants investigation through clinical trials.

Ripretinib for the treatment of advanced, imatinib-resistant gastrointestinal stromal tumors

Discovery of constitutive activation of KIT/PDGFRA tyrosine kinases in gastrointestinal stromal tumors (GISTs) leads to the development of the targeted drug imatinib. However, the inevitable development of imatinib resistance remains a major issue. Ripretinib is a novel targeted drug that inhibits the activities of a broad spectrum of drug-resistant KIT/PDGFRA mutants. It was approved in 2020 and is currently recommended by major international guidelines as the fourth-line and beyond therapy for advanced GISTs. Emerging evidence shows that ripretinib is superior to sunitinib as a second-line treatment for KIT exon 11-mutated GISTs due to its activity against highly heterogeneous frequently occurring secondary mutations. This review summarizes current data on the use of ripretinib to treat advanced imatinib-resistant GISTs. We also propose future research directions to improve the targeted GIST treatment.

Is Autophagy Targeting a Valid Adjuvant Strategy in Conjunction with Tyrosine Kinase Inhibitors?

Tyrosine kinase inhibitors (TKIs) represent a relatively large class of small-molecule inhibitors that compete with ATP for the catalytic binding site of tyrosine kinase proteins. While TKIs have demonstrated effectiveness in the treatment of multiple malignancies, including chronic myelogenous leukemia, gastrointestinal tumors, non-small cell lung cancers, and HER2-overexpressing breast cancers, as is almost always the case with anti-neoplastic agents, the development of resistance often imposes a limit on drug efficacy. One common survival response utilized by tumor cells to ensure their survival in response to different stressors, including anti-neoplastic drugs, is that of autophagy. The autophagic machinery in response to TKIs in multiple tumor models has largely been shown to be cytoprotective in nature, although there are a number of cases where autophagy has demonstrated a cytotoxic function. In this review, we provide an overview of the literature examining the role that autophagy plays in response to TKIs in different preclinical tumor model systems in an effort to determine whether autophagy suppression or modulation could be an effective adjuvant strategy to increase efficiency and/or overcome resistance to TKIs.

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

BACKGROUND

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

AIM

To further investigate the mechanism of IGF2 specific to GISTs.

METHODS

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

RESULTS

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

CONCLUSION

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

Different efficacy of tyrosine kinase inhibitors by KIT and PGFRA mutations identified in circulating tumor DNA for the treatment of refractory gastrointestinal stromal tumors

BACKGROUND

While advanced gastrointestinal stromal tumors (GISTs) are primarily treated with tyrosine kinase inhibitors (TKIs), acquired resistance from specific mutations in KIT or PDGFRA frequently occurs. We aimed to assess the utility of circulating tumor DNA (ctDNA) as a modality of therapeutic decision-making in advanced GIST.

METHODS

We conducted a pooled analysis of SCRUM-Japan studies for advanced GIST patients. We compared patient characteristics analyzed with tissue and blood samples, assessed gene alteration profiles, and evaluated prognostic implications from ctDNA status.

RESULTS

In 133 patients, tissue and blood samples were analyzed for 89 and 44 patients, respectively. ctDNA was detected in 72.7% of cases; no prior treatment or progressive disease was significantly associated with ctDNA-positivity. ctDNA-positive patients had significantly shorter progression-free survival compared with ctDNA-negative patients (hazard ratio = 3.92; P = 0.007). ctDNA genotyping revealed a complex landscape of gene alterations, characterized by multi-exonic mutations in KIT, compared with tissue-based analysis. Patients who received TKIs matched to the identified KIT mutation in ctDNA demonstrated significantly longer PFS than those with unmatched treatment (median, 8.23 vs. 2.43 months; P < 0.001).

CONCLUSIONS

ctDNA-based analysis facilitates assessment of disease status and genomic profiles, thus potentially assisting in identifying optimal therapeutic strategies for advanced GIST patients.

Survival of advanced/recurrent gastrointestinal stromal tumors treated with tyrosine kinase inhibitors in Taiwan: a nationwide registry study

BACKGROUND

Most gastrointestinal stromal tumors (GISTs) harbor c-KIT or PDGFRA mutations. Administration of tyrosine kinase inhibitors (TKIs) has significantly improved the survival of patients with GISTs. We aimed to evaluate the clinical outcome of advanced or recurrent GIST patients in Taiwan.

METHODS

Patients diagnosed between 2010 and 2020 were enrolled. The collected data included baseline characteristics, treatment pattern, treatment outcome, genetic aberrations and survival status. Progression-free survival (PFS) and overall survival (OS) were analyzed and plotted with the Kaplan-Meier method. Cox regression analysis was used to analyze the prognostic factors of survival.

RESULTS

A total of 224 patients with advanced or recurrent GISTs treated with TKIs were enrolled. All patients received imatinib treatment. Ninety-three and 42 patients received sunitinib and regorafenib treatment, respectively. The 48-month PFS and OS rates for patients treated with imatinib were 50.5% and 79.5%, respectively. c-KIT exon 9 and PDGFRA mutations were prognostic factors for a poor PFS and PDGFRA mutation was a prognostic factor for a poor OS in patients treated with imatinib in multivariate Cox regression analysis. The median PFS of patients who received sunitinib treatment was 12.76 months (95% confidence interval (CI), 11.01-14.52). Patients with c-KIT exon 9 mutations had a longer PFS than those with other genetic aberrations. The median PFS of patients treated with regorafenib was 7.14 months (95% CI, 3.39-10.89).

CONCLUSIONS

We present real-world clinical outcomes for advanced GIST patients treated with TKIs and identify mutational status as an independent prognostic factor for patient survival.

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.

Neoadjuvant Imatinib in Gastrointestinal Stromal Tumors (GIST): The First Analysis of a Mexican Population

Introduction Gastrointestinal stromal tumors (GISTs) are neoplasms originating from the interstitial cells of Cajal, pacemaker cells responsible for intestinal motility. Patients with locally advanced GISTs and those with borderline resections due to the proximity of vital anatomical structures, which could result in unacceptable post-surgical morbidity, require special therapeutic consideration. Imatinib, a tyrosine kinase inhibitor, has demonstrated significant success in the non-surgical management of metastatic GIST, and its favorable impact on overall survival in the adjuvant setting makes it logical to speculate on the benefit it could provide as a neoadjuvant medication in patients with locally advanced disease. Methods Patients aged 18-90 years with a diagnosis of GIST confirmed by immunohistochemistry (CD117 positivity) who were treated at the Oncology Hospital of Centro Médico Nacional Siglo XXI in Mexico City from January 2012 to December 2016 were included in the study. It is a retrospective study with a duration of four years. Clinical data were collected from the medical records, which included sex, age, tumor location, initial resectability, reason for unresectability, initial tumor size, and mitotic rate. In the case of unresectable disease, patients who were evaluated by medical oncology and who had received treatment with 400 mg of imatinib daily were evaluated. Results A total of 312 patients diagnosed with GIST were analyzed. One hundred thirty-one were men (42%) with a mean age of 57 years, and 181 were women (58%) with a mean age of 59 years. The most frequent anatomical location was the stomach (n=185, 59.2%). At the time of diagnosis, 210 patients (67.3%) presented with resectable disease, while n=102 patients (32.7%) had unresectable disease. A total of 102 patients with unresectable disease received therapy with 400 mg of imatinib per day. Sixteen patients (15.7%) presented a reduction in tumor dimensions and underwent surgery. Conclusion The study highlights the importance of complete surgical resection and the potential benefit of neoadjuvant imatinib therapy in converting unresectable to resectable disease. The results suggest that imatinib can be effective in converting unresectable GISTs to resectable ones, allowing for a complete resection to be performed and obtaining an R0 resection in 93.7% of these cases.

Huge Gastrointestinal Stromal Tumor (GIST) in Upper Gastrointestinal Masquerade Anaemia

Gastrointestinal stromal tumor (GIST) represents a rare neoplasm affecting the gastrointestinal (GI) tract and is classified as a common nonepithelial tumor within the GI tract. It originates from the interstitial cells of Cajal, and GIST typically manifests with symptoms such as abdominal pain, weight loss, and gastrointestinal bleeding. This case involves a 33-year-old male who presented with GI bleeding symptoms after eight months of treatment for anemia. Oesophagogastroduodenoscopy (OGDS) revealed a singular ulcerated mass measuring 4x4cm while a computed tomography (CT) scan identified a large fundal exophytic component extending from the gastroesophageal junction to the stomach. Subsequently, the patient underwent a laparotomy and proximal gastrectomy with Roux-en-Y reconstruction, which revealed a 12x10 cm tumor located at the fundus of the stomach. This report aims to underscore the potential for misdiagnosis in the initial presentation of GIST, emphasizing the importance of raising clinical awareness in such cases.

Clinicopathological Characteristics and the First Mutational Analysis of Gastrointestinal Stromal Tumors From Mexico: A Single Institution Experience

Background Gastrointestinal stromal tumors (GISTs) arise from Cajal's interstitial cell precursors and display a variety of genetic mutations, primarily in the KIT and PDGFRA genes. These mutations are linked to tumor location, prognosis, and response to treatment. This study delves into the mutational patterns of GISTs in a Mexican population and their impact on overall survival (OS) and disease-free survival (DFS). Methodology This retrospective study examined 42 GIST cases diagnosed at the Oncology Hospital of the National Medical Center XXI Century between January 2018 and December 2020. Clinical, histological, and immunohistochemical data were gathered, and mutational analysis of KIT and PDGFRA genes was conducted using second-generation sequencing. Results The study group consisted of 52.4% females and 47.6% males, with an average age of 62.6 years. The most common tumor site was the stomach (59.5%), followed by the small intestine (26.2%). KIT mutations were detected in 71.4% of cases, predominantly involving exon 11. PDGFRA mutations were observed in 7.1% of cases. Recurrence was noted in 9.5% of patients, all with high-risk tumors. No significant link was identified between specific mutations and OS or DFS. Conclusions This investigation sheds light on the genetic landscape of GISTs in the Mexican population. While no significant association was established between particular mutations and survival outcomes, the study emphasizes the importance of molecular profiling in treatment decision-making. Further studies with larger sample sizes and longer follow-up periods are necessary to validate these results and explore their clinical relevance.

Automated machine learning for predicting liver metastasis in patients with gastrointestinal stromal tumor: a SEER-based analysis

Gastrointestinal stromal tumors (GISTs) are a rare type of tumor that can develop liver metastasis (LIM), significantly impacting the patient's prognosis. This study aimed to predict LIM in GIST patients by constructing machine learning (ML) algorithms to assist clinicians in the decision-making process for treatment. Retrospective analysis was performed using the Surveillance, Epidemiology, and End Results (SEER) database, and cases from 2010 to 2015 were assigned to the developing sets, while cases from 2016 to 2017 were assigned to the testing set. Missing values were addressed using the multiple imputation technique. Four algorithms were utilized to construct the models, comprising traditional logistic regression (LR) and automated machine learning (AutoML) analysis such as gradient boost machine (GBM), deep neural net (DL), and generalized linear model (GLM). We evaluated the models' performance using LR-based metrics, including the area under the receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA), as well as AutoML-based metrics, such as feature importance, SHapley Additive exPlanation (SHAP) Plots, and Local Interpretable Model Agnostic Explanation (LIME). A total of 6207 patients were included in this study, with 2683, 1780, and 1744 patients allocated to the training, validation, and test sets, respectively. Among the different models evaluated, the GBM model demonstrated the highest performance in the training, validation, and test cohorts, with respective AUC values of 0.805, 0.780, and 0.795. Furthermore, the GBM model outperformed other AutoML models in terms of accuracy, achieving 0.747, 0.700, and 0.706 in the training, validation, and test cohorts, respectively. Additionally, the study revealed that tumor size and tumor location were the most significant predictors influencing the AutoML model's ability to accurately predict LIM. The AutoML model utilizing the GBM algorithm for GIST patients can effectively predict the risk of LIM and provide clinicians with a reference for developing individualized treatment plans.

An Extragastrointestinal Stromal Tumor Arising From the Omentum in a Young Hispanic Male

Gastrointestinal stromal tumors (GISTs) are neoplasms arising from the bowel wall, most often in the jejunoileum of the small intestine, but rarely from extragastrointestinal locations. GISTs most often occur in patients older than 40 years of age and can present with a multitude of gastrointestinal symptoms. We present a rare case of an extragastrointestinal stromal tumor (EGIST) causing abdominal pain and melena in a 34-year-old Hispanic male. The patient presented with diffuse abdominal pain, melena, and severe anemia. Computed tomography of the abdomen revealed a large mass abutting the small bowel. The patient was taken to surgery where the mass, which appeared to be deriving from the omentum and invading the adjacent small bowel, was completely excised and found to be a spindle cell GIST. Excision margins were determined to be negative, and the patient was started on a tyrosine kinase inhibitor for maintenance therapy. The patient continues to follow up on an outpatient basis for surveillance. This case represents the rare disease entity EGIST presenting outside the typical demographics of the disease in a young patient with no identified previous genetic syndromes. Gross examination of the mass in this case was also atypical given the appearance that the mass was rooted in the omentum and invading the small bowel which would suggest the primary tumor site was extragastrointestinal. This case demonstrates the need to build a differential diagnosis that includes GIST and the ability to successfully treat this disease if it is identified early in the clinical course.

Development and validation of a preoperative risk nomogram prediction model for gastric gastrointestinal stromal tumors

BACKGROUND AND STUDY AIMS

Gastrointestinal stromal tumors (GIST) carry a potential risk of malignancy, and the treatment of GIST varies for different risk levels. However, there is no systematic preoperative assessment protocol to predict the malignant potential of GIST. The aim of this study was to develop a reliable and clinically applicable preoperative nomogram prediction model to predict the malignant potential of gastric GIST.

PATIENTS AND METHODS

Patients with a pathological diagnosis of gastric GIST from January 2015 to December 2021 were screened retrospectively. Univariate and multivariate logistic analyses were used to identify independent risk factors for gastric GIST with high malignancy potential. Based on these independent risk factors, a nomogram model predicting the malignant potential of gastric GIST was developed and the model was validated in the validation group.

RESULTS

A total of 494 gastric GIST patients were included in this study and allocated to a development group (n = 345) and a validation group (n = 149). In the development group, multivariate logistic regression analysis revealed that tumor size, tumor ulceration, CT growth pattern and monocyte-to- lymphocyte ratio (MLR) were independent risk factors for gastric GIST with high malignancy potential. The AUC of the model were 0.932 (95% CI 0.890-0.974) and 0.922 (95% CI 0.868-0.977) in the development and validation groups, respectively. The best cutoff value for the development group was 0.184, and the sensitivity and specificity at this value were 0.895 and 0.875, respectively. The calibration curves indicated good agreement between predicted and actual observed outcomes, while the DCA indicated that the nomogram model had clinical application.

CONCLUSIONS

Tumor size, tumor ulceration, CT growth pattern and MLR are independent risk factors for high malignancy potential gastric GIST, and a nomogram model developed based on these factors has a high ability to predict the malignant potential of gastric GIST.

The GIST of it all: management of gastrointestinal stromal tumors (GIST) from the first steps to tailored therapy. A bibliometric analysis

PURPOSE

Improvement of patient care is associated with increasing publication numbers in biomedical research. However, such increasing numbers of publications make it challenging for physicians and scientists to screen and process the literature of their respective fields. In this study, we present a comprehensive bibliometric analysis of the evolution of gastrointestinal stromal tumor (GIST) research, analyzing the current state of the field and identifying key open questions going beyond the recent advantages for future studies to assess.

METHODS

Using the Web of Science Core Collection, 5040 GIST-associated publications in the years 1984-2022 were identified and analyzed regarding key bibliometric variables using the Bibliometrix R package and VOSviewer software.

RESULTS

GIST-associated publication numbers substantially increased over time, accentuated from year 2000 onwards, and being characterized by multinational collaborations. The main topic clusters comprise surgical management, tyrosine kinase inhibitor (TKI) development/treatment, diagnostic workup, and molecular pathophysiology. Within all main topic clusters, a significant progress is reflected by the literature over the years. This progress ranges from conventional open surgical techniques over minimally invasive, including robotic and endoscopic, resection techniques to increasing identification of specific functional genetic aberrations sensitizing for newly developed TKIs being extensively investigated in clinical studies and implemented in GIST treatment guidelines. However, especially in locally advanced, recurrent, and metastatic disease stages, surgery-related questions and certain specific questions concerning (further-line) TKI treatment resistance were infrequently addressed.

CONCLUSION

Increasing GIST-related publication numbers reflect a continuous progress in the major topic clusters of the GIST research field. Especially in advanced disease stages, questions related to the interplay between surgical approaches and TKI treatment sensitivity should be addressed in future studies.

Proteomic Characterization Identifies Clinically Relevant Subgroups of Gastrointestinal Stromal Tumors

BACKGROUND & AIMS

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract, and it has high metastatic and recurrence rates. We aimed to characterize the proteomic features of GIST to understand biological processes and treatment vulnerabilities.

METHODS

Quantitative proteomics and phosphoproteomics analyses were performed on 193 patients with GIST to reveal the biological characteristics of GIST. Data-driven hypotheses were tested by performing functional experiments using both GIST cell lines and xenograft mouse models.

RESULTS

Proteomic analysis revealed differences in the molecular features of GISTs from different locations or with different histological grades. MAPK7 was identified and functionally proved to be associated with tumor cell proliferation in GIST. Integrative analysis revealed that increased SQSTM1 expression inhibited the patient response to imatinib mesylate. Proteomics subtyping identified 4 clusters of tumors with different clinical and molecular attributes. Functional experiments confirmed the role of SRSF3 in promoting tumor cell proliferation and leading to poor prognosis.

CONCLUSIONS

Our study provides a valuable data resource and highlights potential therapeutic approaches for GIST.

Acute Pyelonephritis and an Incidental Diagnosis

Gastrointestinal stromal tumors (GISTs) arise from the gastrointestinal tract. In rare cases, extra-gastrointestinal stromal tumors (EGISTs) occur in the omentum, mesentery, et cetera. They are mostly asymptomatic or have unspecific symptoms. Risk stratification classification systems are based on tumor size, mitotic rate, location, and perforation. The gold standard for diagnosis is a computed tomography (CT) scan. Ultrasound/CT-guided percutaneous biopsy allows histopathology and immunochemistry results (most stain positive for CD117 (c-KIT), CD34, and/or DOG1). Mutational analysis (most are in proto-oncogene c-KIT and platelet-derived growth factor receptor A (PDGFRA)) determines appropriate therapy. Surgical resection is the gold standard of treatment, with adjuvant and neoadjuvant molecular-targeted therapies depending on recurrence risk and mutations. This report describes a rare case of GIST (omentum EGIST) with a rare presentation (acute pyelonephritis) in a 67-year-old woman. Abdominal examination showed tenderness and a positive Murphy sign on the left side. Blood analysis presented microcytic hypochromic anemia, aggravated renal function, leukocytosis, and increased C-reactive protein. Abdominal CT revealed a heterogeneous abdominal mass, and a CT-guided biopsy showed epithelioid cells positive for CD117 and DOG1, which is compatible with a GIST. The patient underwent surgery that determined the GIST's origin from the greater omentum. Histology revealed an epithelioid GIST with large dimensions and a high histologic grade. Genetic testing detected a variant in the PDGFRA gene. With a high risk of progression, the patient received a three-year course of imatinib.

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

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

Advances in Drug Therapy for Gastrointestinal Stromal Tumour

INTRODUCTION

Gastrointestinal stromal tumour (GIST) is a common gastrointestinal sarcoma located in the stromal cells of the digestive tract, and molecular studies have revealed the pathogenesis of mutations in KIT and PDGFRA genes. Since imatinib opened the era of targeted therapy for GIST, tyrosine kinase inhibitors (TKIs) that can treat GIST have been developed successively. However, the lack of new drugs with satisfactory therapeutic standards has made addressing resistance a significant challenge for TKIs in the face of the resistance to first-line and second-line drugs. Therefore, we need to find as many drugs and new treatments that block mutated genes as possible.

METHODS

We conducted a comprehensive collection of literature using databases, integrated and analysed the selected literature based on keywords and the comprehensive nature of the articles, and finally wrote articles based on the content of the studies.

RESULTS

In this article, we first briefly explained the relationship between GIST and KIT/ PDGFRα and then introduced the related drug treatment. The research progress of TKIs was analyzed according to the resistance of the drugs.

CONCLUSION

This article describes the research progress of some TKIs and briefly introduces the currently approved TKIs and some drugs under investigation that may have better therapeutic effects, hoping to provide clues to the research of new drugs.

Diagnosis, Treatment, and Prognosis of Patients with Primary Familial Gastrointestinal Stromal Tumor: A Case Report and Literature Review

Gastrointestinal stromal tumors are the most common mesenchymal tumors of the digestive tract, most of which are sporadic, and familial GISTs with germline mutations are rarely seen. Here, we report a 26-year-old female with a germline p. W557R mutation in exon 11 of the KIT gene. The proband and her father and sister presented with multifocal GIST and pigmented nevi. All 3 patients underwent surgery and imatinib therapy. To date, only 49 kindreds with germline KIT mutations and 6 kindreds with germline PDGFRA mutations have been reported. Summarizing the reported kindreds, the majority of familial GISTs manifest as multiple primary GISTs complicated with special clinical manifestations, including cutaneous hyperpigmentation, dysphagia, mastocytosis, inflammatory fibrous polyps, and large hands. Familial GISTs are generally thought to exhibit TKI sensitivity similar to that of sporadic GISTs with the same mutation.

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 prognostic role of gastrointestinal bleeding in patients with a primary gastrointestinal stromal tumor: a long-term follow-up study

Background

Gastrointestinal (GI) bleeding is one of the common symptoms of GI stromal tumor (GIST). Although several studies have highlighted its prognostic role, conclusions have been inconsistent. This study aimed to investigate the prognosis of GIST patients with GI bleeding.

Methods

Primary GIST patients who underwent complete resection and did not receive adjuvant imatinib therapy from January 2003 to December 2008 were reviewed. The Kaplan-Meier method was used to estimate recurrence-free survival (RFS), and multivariate analysis was performed using the Cox proportional hazard model. Propensity score matching (PSM) was conducted to reduce confounders. A systematic review of the published articles in the PubMed, Embase, Cochrane Collaboration, and Medline databases was also conducted, and the inclusion criteria were determined using PICOS (patients, intervention, comparison, outcomes, and study design) principles.

Results

In total, 84 patients presenting with GI bleeding and 90 patients without GI bleeding were enrolled in this study. The median time of follow-up was 140 months (range, 10-196 months), and 38 patients developed tumor recurrence/metastasis. For all patients, the multivariate analysis indicated that tumor location [hazard ratio (HR) =3.48, 95% confidence interval (CI): 1.78-6.82, P<0.001], tumor size (HR =1.91, 95% CI: 1.05-3.47, P=0.035), mitotic index (MI; HR =5.69, 95% CI: 2.77-11.67, P<0.001), and age (HR =2.68, 95% CI: 1.49-4.82, P=0.001) were the independent prognostic factors for poor RFS. However, GI bleeding was not associated with RFS (HR =1.21, 95% CI: 0.68-2.14, P=0.518). After PSM, 45 patients from each group were included, and it was found that GI bleeding was still not the independent prognostic factor (HR =1.23, 95% CI: 0.51-2.97, P=0.642). Moreover, the pooled results of our study and six previously reported studies showed that GI bleeding was not the independent prognostic factor (HR =1.45, 95% CI: 0.73-2.86, P=0.287).

Conclusions

In this study, tumor location, tumor size, MI, and age were independent prognostic factors in primary GIST patients who underwent radical resection. However, GI bleeding was not associated with worse RFS.