Gastrointestinal Stromal Tumors

SMYD2 aggravates gastrointestinal stromal tumor via upregulation of EZH2 and downregulation of TET1

SMYD2, as an oncogene, has been involved in multiple types of cancer, but the potential role of SMYD2 in gastrointestinal stromal tumors (GIST) remains enigmatic and requires further investigation. Hence, this study was conducted with the main objective of analyzing the effect of SMYD2 on GIST. GIST and adjacent normal tissues were collected from 46 patients with GIST where the expression of EZH2, SMYD2, and TET1 was determined, followed by the analysis of their interactions. The functional role of SMYD2 in cell biological functions was determined using a loss-of-function assay in GIST-T1 cells. Nude mouse xenograft experiments were performed to verify the role of the SMYD2/EZH2/TET1 axis in GIST in vivo. EZH2 was upregulated in GIST tissues and cell lines, which was positively correlated with SMYD2 expression and inversely correlated with TET1 expression in GIST tissues. EZH2 silencing due to SMYD2 inhibition reduced GIST-T1 cell proliferation and accelerated cell senescence. EZH2 repressed TET1 expression by promoting H3K27me3 methylation in the TET1 promoter region. TET1 inhibition reversed the effect of EZH2 silencing on the biological functions of GIST-T1 cells. In vivo data further revealed the promoting effect of SMYD2 on the progression of GIST by regulating the EZH2/TET1 axis. Overall, this study demonstrates that SMYD2 can increase EZH2 expression while suppressing TET1 expression, thus accelerating GIST, and creating new treatment opportunities for GIST.

c-Abl-induced Olig2 phosphorylation regulates the proliferation of oligodendrocyte precursor cells

Oligodendrocytes (OLs), the myelinating cells in the central nervous system (CNS), are differentiated from OL progenitor cells (OPCs). The proliferation of existing OPCs is indispensable for myelination during CNS development and remyelination in response to demyelination stimulation. The transcription factor Olig2 is required for the specification of OLs and is expressed in the OL lineage. However, the post-translational modification of Olig2 in the proliferation of OPCs is poorly understood. Herein, we identified that c-Abl directly phosphorylates Olig2 mainly at the Tyr137 site, and that Olig2 phosphorylation is essential for OPC proliferation. The expression levels of c-Abl gradually decreased with brain development; moreover, c-Abl was highly expressed in OPCs. OL-specific c-Abl knockout at the developmental stage led to an insufficient proliferation of OPCs, a decreased expression of myelin-related genes, and myelination retardation. Accordingly, a c-Abl-specific kinase inhibitor suppressed OPC proliferation in vitro. Furthermore, we observed that OL-specific c-Abl knockout reduced OPC proliferation and remyelination in a cuprizone model of demyelination. In addition, we found that nilotinib, a clinically used c-Abl inhibitor, decreased the expression of myelin basic protein (Mbp) and motor coordination in mice, indicating a neurological side effect of a long-term administration of the c-Abl inhibitor. Thus, we identified the important role of c-Abl in OLs during developmental myelination and remyelination in a disease model.

Tropomyosin-Related Kinase Fusions in Gastrointestinal Stromal Tumors

Simple Summary

The canonical mutations in gastrointestinal stromal tumors (GISTs) are typically activating mutations in KIT and platelet-derived growth factor receptor alpha (PDGFRA). Imatinib, the treatment of choice for GISTs, shows a lower response in KIT/PDGFRA wild-type GISTs. Neurotrophic tyrosine receptor kinase (NTRK) fusion, which can be treated with an NTRK target agent, has been reported in KIT/PDGFRA wild-type GISTs, and, therefore, the Yonsei Cancer Center analyzed NTRK fusion incidence in KIT/PDGFRA wild-type GISTs. At the Yonsei Cancer Center, NTRK fusion was confirmed in 16% of cases. Confirmation of NTRK fusion in KIT/PDGFRA wild-type GISTs provides important information for improving therapeutic outcomes. NTRK fusion was confirmed in 16% of KIT/PDGFRA wild-type GIST cases at the Yonsei Cancer Center. Confirmation of NTRK fusion in KIT/PDGFRA wild-type GISTs will improve therapeutic outcomes.

Abstract

The canonical mutations in gastrointestinal stromal tumors (GISTs) are typically activating mutations in KIT and platelet-derived growth factor receptor alpha (PDGFRA). GISTs with non-canonical mutations are a heterogeneous group. Here, we examined tropomyosin-related kinase (TRK) fusion in GIST cases without KIT/PDGFRA mutations (KIT/PDGFRA wild-type (WT) GISTs). We retrospectively analyzed patients who were diagnosed with GISTs at the Yonsei Cancer Center, Severance Hospital, between January 1998 and December 2016. Thirty-one patients with KIT/PDGFRA WT GISTs were included in the analysis. TRK expression in tumor samples was assessed by pan-TRK immunohistochemistry (IHC), and the neurotrophic tyrosine receptor kinase (NTRK: the gene encoding TRK) rearrangement was analyzed by fluorescence in situ hybridization (FISH). IHC analyses revealed that five cases in this cohort exhibited a weak to moderate TRK expression. NTRK1 fusions were detected in three tumor samples, and two samples harbored NTRK3 fusions. The remaining 26 samples did not harbor NTRK fusions. Two types of NTRK fusions were detected, and the overall NTRK fusion frequency in KIT/PDGFRA WT GIST cases was 16% (5/31). Our data provide insights into the molecular alterations underpinning KIT/PDGFRA WT GISTs. More effort should be devoted to improve methods to identify this distinct disease subtype within the KIT/PDGFRA WT GIST group.

The Molecular Biology of Soft Tissue Sarcomas: Current Knowledge and Future Perspectives

Simple Summary

Over the past 20 years, significant advances in the field of genetics and molecular biology have led to the dismantlement of multiple subtypes of sarcomas. As a result, molecular approaches nowadays play a critical role in the diagnosis, prognostic classification, and therapeutic management of numerous mesenchymal tumor subtypes. This review of the current literature illustrates the main uses of molecular biology in the field of soft tissue sarcomas and the future challenges that remain to be addressed.

Abstract

Soft tissue sarcomas are malignant tumors of mesenchymal origin, encompassing a large spectrum of entities that were historically classified according to their histological characteristics. Over the last decades, molecular biology has allowed a better characterization of these tumors, leading to the incorporation of multiple molecular features in the latest classification of sarcomas as well as to molecularly-guided therapeutic strategies. This review discusses the main uses of molecular biology in current practice for the diagnosis and treatment of soft tissue sarcomas, in addition to perspectives for this rapidly evolving field of research.

Preoperative prediction of malignant potential of 2-5 cm gastric gastrointestinal stromal tumors by computerized tomography-based radiomics

BACKGROUND

The use of endoscopic surgery for treating gastrointestinal stromal tumors (GISTs) between 2 and 5 cm remains controversial considering the potential risk of metastasis and recurrence. Also, surgeons are facing great difficulties and challenges in assessing the malignant potential of 2-5 cm gastric GISTs.

AIM

To develop and evaluate computerized tomography (CT)-based radiomics for predicting the malignant potential of primary 2-5 cm gastric GISTs.

METHODS

A total of 103 patients with pathologically confirmed gastric GISTs between 2 and 5 cm were enrolled. The malignant potential was categorized into low grade and high grade according to postoperative pathology results. Preoperative CT images were reviewed by two radiologists. A radiological model was constructed by CT findings and clinical characteristics using logistic regression. Radiomic features were extracted from preoperative contrast-enhanced CT images in the arterial phase. The XGboost method was used to construct a radiomics model for the prediction of malignant potential. Nomogram was established by combing the radiomics score with CT findings. All of the models were developed in a training group (n = 69) and evaluated in a test group (n = 34).

RESULTS

The area under the curve (AUC) value of the radiological, radiomics, and nomogram models was 0.753 (95% confidence interval [CI]: 0.597-0.909), 0.919 (95%CI: 0.828-1.000), and 0.916 (95%CI: 0.801-1.000) in the training group vs 0.642 (95%CI: 0.379-0.870), 0.881 (95%CI: 0.772-0.990), and 0.894 (95%CI: 0.773-1.000) in the test group, respectively. The AUC of the nomogram model was significantly larger than that of the radiological model in both the training group (Z = 2.795, P = 0.0052) and test group (Z = 2.785, P = 0.0054). The decision curve of analysis showed that the nomogram model produced increased benefit across the entire risk threshold range.

CONCLUSION

Radiomics may be an effective tool to predict the malignant potential of 2-5 cm gastric GISTs and assist preoperative clinical decision making.

Molecular Portrait of GISTs Associated With Clinicopathological Features: A Retrospective Study With Molecular Analysis by a Custom 9-Gene Targeted Next-Generation Sequencing Panel

Objectives: The study aims to investigate genetic characterization of molecular targets and clinicopathological features with gastrointestinal stromal tumors based on targeted next-generation sequencing.

Materials and Methods: We selected 106 patients with GISTs from Sir Run Run Shaw Hospital between July 2019 and March 2021. FFPE samples and paired blood samples were obtained from these patients who underwent excision of the tumor. A customized targeted-NGS panel of nine GIST-associated genes was designed to detect variants in the coding regions and the splicing sites of these genes.

Results: In total, 106 patients with a GIST were included in the study which presented with various molecular driver alterations in this study. KIT mutations occurred most often in GISTs (94/106, 95.92%), followed by point mutations in PDGFRA. KIT or PDGFRA mutations were detected to be mutually exclusive in the GIST. A total of eight patients with wide-type KIT/PDGFRA were characterized as WT-GISTs, according to clinical diagnosis which included six quadruple-WT GISTs, 1 BRAF-mutant, and 1 NF1-mutant GIST. In KIT exon 11, the most common mutation type was the codon Mutation (in-frame deletion or indels), whereas the missense mutation was the dominant type in KIT exon 13 and KIT exon 17. All variations in KIT exon 11 observed in this study were concentrated at a certain position of codon 550 to codon 576. Mutation in KIT exon 9 was mostly located at codon 502–503. Two germline pathogenic mutations were detected: NF1-R681* and KRAS-T58I. NF1-L591P was a germline mutation to be identified for the first time and is not recorded in the database. The frequency of driving mutations differed between the primary anatomical site in the GIST (p = 0.0206). KIT exon 11 mutants had a lower proliferation index of Ki67 (68.66%,≤5%), while 50.00% of KIT exon 9 mutants had the Ki67 status greater than 10%.

Conclusion: The occurrence and development of a GIST is driven by different molecular variations. Resistance to TKIs arises mainly with resistance mutations in KIT or PDGFRA when they are the primary drivers. Targeted NGS can simultaneously and efficiently detect nine GIST-related gene mutations and provide reference for clinicians’ individualized diagnosis and treatment. Our results have important implications for clinical management.

In Vivo Evaluation of Fibroblast Growth Factor Receptor Inhibition in Mouse Xenograft Models of Gastrointestinal Stromal Tumor

Advanced gastrointestinal stromal tumors (GIST) are typically treated with tyrosine kinase inhibitors, and imatinib is the most commonly used standard of care in first line treatments. The use of this and other tyrosine kinase inhibitors is associated with objective tumor responses and prolongation of progression-free and overall survival, but the treatment of metastatic disease is non-curative due to the selection or acquisition of secondary mutations and the activation of alternative kinase signaling pathways, leading to resistance and disease progression after an initial response. The present preclinical study evaluated the potential use of the fibroblast growth factor receptor inhibitors infigratinib and dovitinib alone or in combination with the mitogen-activated protein kinase inhibitor binimetinib in mouse models of GIST with different sensitivity or resistance to imatinib. Patient- and cell-line-derived GIST xenografts were established by bilateral, subcutaneous transplantation of human GIST tissue in female adult nu/nu NMRI mice. The mice were treated with dovitinib, infigratinib, or binimetinib, either alone or in combination with imatinib. The safety of treated animals was assessed by well-being inspection and body weight measurement. Antitumor effects were assessed by caliper-based tumor measurement. H&E staining and immunohistochemistry were used for assessing anti-mitotic and pro-apoptotic activity of the experimental treatments. Western blotting was used for assessing effects of the agents on kinase signaling pathways. Anti-angiogenic activity was assessed by measuring tumor vessel density. Dovitinib was found to have antitumor efficacy in GIST xenografts characterized by different imatinib resistance patterns. Dovitinib had better efficacy than imatinib (both at standard and increased dose) and was found to be well tolerated. Dovitinib had better efficacy in a KIT exon 9 mutant model, highlighting a role of patient selection in clinical GIST trials with the agent. In a model with KIT exon 11 and 17 mutations, dovitinib induced tumor necrosis, most likely due to anti-angiogenic effects. Additive effects combining dovitinib with binimetinib were limited.

Oncogenic KIT Induces Replication Stress and Confers Cell Cycle Checkpoint Vulnerability in Melanoma

Acral and mucosal melanomas arise from sun-protected sites, disproportionately impact darker-skinned individuals, and exact higher mortality than common types of cutaneous melanoma. Genetically, acral and mucosal melanomas harbor more alterations of KIT than typical cutaneous melanomas. Because KIT-mutated melanomas remain largely treatment resistant, we set out to create a faithful murine KIT-driven allograft model to define newer therapeutic strategies. Using the prevalent human KITK642E activating mutation, the murine mKITK641E cellular avatars show features of transformation in vitro and tumorigenicity in immunocompetent C57BL/6J mice. mKITK641E cells proliferate more rapidly, exhibit greater chromosomal aberrations, and sustain three-dimensional spheroid expansion and aggressive tumor growth in C57BL/6J mice compared with their vector-controlled cells. We further verified the functional dependence of these cells on KITK641E with both genetic and pharmacologic suppression. Using these cells, we performed a screen of 199 kinase inhibitors and identified a selective vulnerability to Chk1/ATR inhibition in the KITK641E-activated cells. Mechanistically, we subsequently showed that KITK641E induces a significantly increased level of replication stress compared with murine vector‒controlled cells. These results showcase an allograft model of human KIT-driven melanomas, which uncovered an unappreciated role for replication stress in KIT melanomagenesis and implicated a possible therapeutic strategy with Chk1/ATR inhibitors.

Efficacy and Safety of Endoscopic Resection for Small Gastric Gastrointestinal Stromal Tumors in Elderly Patients

Background

Gastrointestinal stromal tumors (GISTs) are prevalent in elderly patients. Endoscopic resection has become popular for treating small (≤5 cm) gastric GISTs. However, little is known about the outcomes of endoscopic resection in elderly patients.

Aim

To assess the efficacy and safety of endoscopic resection for small (≤5 cm) gastric GISTs in elderly patients (≥65 years old).

Methods

A total of 260 patients (265 lesions) with gastric GISTs treated via endoscopic resection from January 2011 to May 2020 were retrospectively analyzed. Among them, 65 patients were ≥65 years old (elderly group), and 195 patients were <65 years old (nonelderly group). Clinicopathological characteristics, postoperative complications, and tumor recurrence rates between the two age groups were compared.

Results

A total of 260 patients with primary small (≤5 cm) gastric GISTs were treated with endoscopic resection. The median ages of the elderly and nonelderly groups were 68 (range 65-83) years and 55 (range 32-64) years, respectively. Elderly patients showed a higher incidence of comorbidities compared with nonelderly patients (61.5% versus 32.3%s, respectively; p < 0.001). All elderly patients and 99.0% of nonelderly patients underwent en bloc resection; only two nonelderly patients received piecemeal resection. No significant differences were found regarding postoperative complications or tumor recurrence rates between the two groups.

Conclusions

Although elderly patients had more comorbidities than nonelderly patients, both groups had similar postoperative complications and recurrence rates. We suggest that endoscopic resection performed by experienced endoscopists is safe and effective for treating small (≤5 cm) gastric GISTs in elderly patients.

Long-term progression-free survival achieved in the skull base metastasis of gastrointestinal stromal tumor with introduction of tyrosine kinase inhibitor: illustrative case

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are common subepithelial tumors that rarely metastasize to the intracranial space. Because the standard treatment for metastatic intracranial GISTs has not been established, multimodal therapies are needed, especially in the case of skull base metastasis. However, its outcome has not always been favorable. The authors report the longest known surviving case of skull base metastasis of GIST treated with imatinib only.

OBSERVATIONS

A 52-year-old male with a history of GIST presented with left facial swelling and numbness. Examinations revealed a 70-mm tumor occupying the left middle cranial fossa and the orbit. The authors performed transnasal endoscopic tumor biopsy for definitive diagnosis and reintroduced imatinib treatment. The tumor significantly decreased in size early after the introduction of imatinib, and symptoms completely disappeared within several weeks. The lesion has remained shrunk radiologically for 63 months, and the patient is continuously being followed up under imatinib treatment.

LESSONS

The authors reported a rare case of skull base metastasis of GIST successfully treated solely with systemic therapy with a tyrosine kinase inhibitor, achieving tumor control for over 5 years. This case suggests that tyrosine kinase inhibitors might play a key role in the multidisciplinary treatment for skull base metastases of GIST.

Adjuvant Imatinib in Patients with GIST Harboring Exon 9 KIT Mutations: Results from a Multi-institutional European Retrospective Study

PURPOSE

The effect of high-dose imatinib (800 mg/day) on survival in the adjuvant treatment of patients with resected KIT exon 9-mutated gastrointestinal stromal tumors (GIST) is not established. Here, the association of dose and other clinicopathologic variables with survival was evaluated in a large multi-institutional European cohort.

EXPERIMENTAL DESIGN

Data from 185 patients were retrospectively collected in 23 European GIST reference centers. Propensity score matching (PSM) and inverse-probability of treatment weighting (IPTW) were used to account for confounders. Univariate and multivariate unweighted and weighted Cox proportional hazard regression models were estimated for relapse-free survival (RFS), modified-RFS (mRFS) and imatinib failure-free survival (IFFS). Univariate Cox models were estimated for overall survival.

RESULTS

Of the 185 patients, 131 (70.8%) received a starting dose of 400 mg/d and the remaining 54 (29.2%) a dose of 800 mg/d. Baseline characteristics were partially unbalanced, suggesting a potential selection bias. PSM and IPTW analyses showed no advantage of imatinib 800 mg/d. In the weighted multivariate Cox models, high-dose imatinib was not associated with the survival outcomes [RFS: hazard ratio (HR), 1.24; 95% confidence interval (CI), 0.79-1.94; mRFS: HR, 1.69; 95% CI, 0.92-3.10; IFFS: HR, 1.35; 95% CI, 0.79-2.28]. The variables consistently associated with worse survival outcomes were high mitotic index and nongastric tumor location.

CONCLUSIONS

In this retrospective series of patients with KIT exon 9-mutated GIST treated with adjuvant imatinib, a daily dose of 800 mg versus 400 mg did not show better results in terms of survival outcomes. Prospective evaluation of the more appropriate adjuvant treatment in this setting is warranted.

Comparison of the Suitability Between NRS2002 and MUST as the First-Step Screening Tool for GLIM Criteria in Hospitalized Patients With GIST

Objective

The Global Leader Initiative on Malnutrition (GLIM) criteria have been recommended for malnutrition diagnosis recently, for which the first step is malnutrition risk screening with any validated tool. This study aims to investigate the incidence of malnutrition risk in gastrointestinal stromal tumor (GIST) inpatients and compare the suitability of Nutritional Risk Screening 2002 (NRS2002) and Malnutrition Universal Screening Tool (MUST) as the first-step screening tool for GLIM criteria.

Methods

We retrospectively analyzed the clinical data of GIST inpatients in our hospital from January 2015 to December 2019. NRS2002 and MUST were used to screen malnutrition risk at the time of admission. The diagnostic consistency of these two tools with GLIM criteria for malnutrition was analyzed, and the predictive performance of both tools for the length of hospital stay and the occurrence of complications was also evaluated in surgical and non-surgical inpatients.

Results

A total of 269 GIST inpatients were included in this study, of which 45.7 and 40.9% were at malnutrition risk determined by NRS2002 and MUST, respectively. In non-surgical inpatients, NRS2002 and MUST had similar diagnostic consistency with GLIM criteria in sensitivity (93.0 vs. 97.7%), specificity (81.1 vs. 81.1%), and Kappa value (K = 0.75 vs. 0.80), and high nutritional risk classified by NRS2002 and malnutrition identified by GLIM criteria were found to be associated with the length of hospital stay. In surgical inpatients, MUST had better diagnostic consistency with GLIM criteria in sensitivity (86.1 vs. 53.5%) and Kappa value (K = 0.61 vs. 0.30) than NRS2002, but no factors were found associated with the length of postoperative hospital stay or the occurrence of complications.

Conclusion

The malnutrition risk is common in GIST inpatients. NRS2002 is more suitable than MUST for the first-step risk screening of the GLIM scheme in non-surgical inpatients, considering its better performance in screening malnutrition risk and predicting clinical outcomes. MUST was found to have good diagnostic consistency with GLIM criteria for malnutrition in both non-surgical and surgical GIST inpatients, and further studies need to be conducted to investigate its predictive performance on clinical outcomes.

Naples prognostic score, a novel prognostic score for patients with high- and intermediate-risk gastrointestinal stromal tumours after surgical resection

BACKGROUND

A novel multidimensional inflammatory and nutritional assessment system named the Naples prognostic score could serve as an independent prognostic indicator. However, its significance in patients with high- and intermediate-risk gastrointestinal stromal tumours remains unclear.

METHODS

We performed this retrospective cohort study based on a prospectively collected database of gastrointestinal stromal tumours (GISTs) between March 2010 and December 2019. The Kaplan-Meier method and log-rank test were used for survival analyses. Least absolute shrinkage and selection operator (LASSO) and Cox proportional hazards regression analysis was used for univariate and multivariate analyses. Time-dependent receiver operating characteristic curves were generated to evaluate the discriminatory ability of the prognostic scoring systems. Differences in the areas under the curve were further compared.

RESULTS

A total of 405 patients with regular follow-up were included and analysed in this study. Significant differences in progression-free survival and overall survival were observed between the groups (P < 0.001). Multivariate analysis demonstrated that the NPS was a significant predictor of poor progression-free survival (1 vs 0, HR = 4.622, P = 0.001; 2 vs 0, HR = 12.770, P < 0.001) and overall survival (2 vs 0, HR = 5.535, P = 0.002). Furthermore, time-dependent AUC analyses showed that the NPS was more accurate than other haematologic prognostic systems.

CONCLUSIONS

The present study demonstrates that the NPS could independently predict disease progression and survival among patients with high- and intermediate-risk GISTs. The NPS might be regarded and applied as one of the most convenient and effective preoperative risk stratification tools in the future, which should be validated by large-scale multicentre prospective cohort studies.

Comparison of Computed Tomography Features of Gastric and Small Bowel Gastrointestinal Stromal Tumors With Different Risk Grades

OBJECTIVE

This study aimed to compare the computed tomography (CT) features of gastric and small bowel gastrointestinal stromal tumors (GISTs) and further identify the predictors for risk stratification of them, respectively.

METHODS

According to the modified National Institutes of Health criteria, patients were classified into low-malignant potential group and high-malignant potential group. Two experienced radiologists reviewed the CT features including the difference of CT values between arterial phase and portal venous phase (PVPMAP) by consensus. The CT features of gastric and small bowel GISTs were compared, and the association of CT features with risk grades was analyzed, respectively. Determinant CT features were used to construct corresponding models.

RESULTS

Univariate analysis showed that small bowel GISTs tended to present with irregular contour, mixed growth pattern, ill-defined margin, severe necrosis, ulceration, tumor vessels, heterogeneous enhancement, larger size, and marked enhancement compared with gastric GISTs. According to multivariate analysis, tumor size (P < 0.001; odds ratio [OR], 3.279), necrosis (P = 0.008; OR, 2.104) and PVPMAP (P = 0.045; OR, 0.958) were the independent influencing factors for risk stratification of gastric GISTs. In terms of small bowel GISTs, the independent predictors were tumor size (P < 0.001; OR, 3.797) and ulceration (P = 0.031; OR, 4.027). Receiver operating characteristic curve indicated that the CT models for risk stratification of gastric and small bowel GISTs both achieved the best predictive performance.

CONCLUSIONS

Computed tomography features of gastric and small bowel GISTs are different. Furthermore, the qualitative and quantitative CT features of GISTs may be favorable for preoperative risk stratification.

Prediction of the Ki-67 expression level and prognosis of gastrointestinal stromal tumors based on CT radiomics nomogram

PURPOSE

To build and validate a radiomics nomogram integrated with the radiomics signature and subjective CT characteristics to predict the Ki-67 expression level of gastrointestinal stromal tumors (GISTs). Moreover, the purpose was to compare the performance of pathological Ki-67 expression level with predicted Ki-67 expression level in estimating the prognosis of GISTs patients.

METHODS

According to pathological results, patients were classified into high-Ki-67 labeling index group (Ki-67 LI ≥ 5%) and low-Ki-67 LI group (Ki-67 LI < 5%). Radiomics features extracted from contrast-enhanced CT(CECT) images were selected and classified to build a radiomics signature. A combined model was built by incorporating radiomics signature and determinant subjective CT characteristics using multivariate logistic regression analysis. The diagnostic performance of the radiomics signature, subjective CT model and combined model were explored by receiver operating characteristic (ROC) curve analysis and Delong test. The model with best diagnostic performance was then set up for the prediction nomogram. Recurrence-free survival (RFS) rates were compared utilizing Kaplan-Meier curve.

RESULTS

The generated combined model yielded the best diagnostic performance with area under the curve (AUC) values of 0.738 [95% confidence interval (CI): 0.669-0.807] and 0.772 (95% CI 0.683-0.860) in the training set and testing set respectively. The nomogram based on the combined model demonstrated good calibration in the training set and testing set (both P > 0.05). Patients of high-Ki-67 LI group predicted by our nomogram had a poorer RFS than patients of low-Ki-67 LI group (P < 0.0001).

CONCLUSION

This radiomics nomogram based on CECT had a satisfactory performance in predicting both the Ki-67 expression level and prognosis noninvasively in patients with GISTs, which may serve as an effective imaging tool that can assist in guiding personalized clinical treatment.

Early experience of laparoscopic resection and comparison with open surgery for gastric gastrointestinal stromal tumor: a multicenter retrospective study

The advantages of laparoscopic resection over open surgery in the treatment of gastric gastrointestinal stromal tumor (GIST) are not conclusive. This study aimed to evaluate the postoperative and oncologic outcome of laparoscopic resection for gastric GIST, compared to open surgery. We retrospectively reviewed the prospectively collected database of 1019 patients with gastric GIST after surgical resection at 13 Korean and 2 Japanese institutions. The surgical and oncologic outcomes were compared between laparoscopic and open group, through 1:1 propensity score matching (PSM). The laparoscopic group (N = 318) had a lower rate of overall complications (3.5% vs. 7.9%, P = 0.024) and wound complications (0.6% vs. 3.1%, P = 0.037), shorter hospitalization days (6.68 ± 4.99 vs. 8.79 ± 6.50, P < 0.001) than the open group (N = 318). The superiority of the laparoscopic approach was also demonstrated in patients with tumors larger than 5 cm, and at unfavorable locations. The recurrence-free survival was not different between the two groups, regardless of tumor size, locational favorableness, and risk classifications. Cox regression analysis revealed that tumor size larger than 5 cm, higher mitotic count, R1 resection, and tumor rupture during surgery were independent risk factors for recurrence. Laparoscopic surgery provides lower rates of complications and shorter hospitalizations for patients with gastric GIST than open surgery.

Relationship Between Nutritional Status and Clinical Outcome in Patients With Gastrointestinal Stromal Tumor After Surgical Resection

Background

Currently, gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors in the gastrointestinal tract, and surgical resection is the main treatment. Malnutrition after gastrointestinal surgery is not uncommon, which may have adverse effects on postoperative recovery and prognosis. However, the nutritional status of GIST patients after surgical resection and its impact on clinical outcomes have received less attention. Therefore, the aim of this study was to dynamically evaluate the nutritional status of GIST patients undergoing surgical resection, and to analyze the correlation between nutritional status and clinical outcomes.

Methods

We retrospectively analyzed the clinical data of GIST patients who underwent surgical resection in the Fourth Hospital of Hebei Medical University from January 2016 to January 2020. Nutritional risk screening 2002 (NRS2002) and Patient-Generated Subjective Global Assessment (PG-SGA) were used to assess the nutritional status of all patients at admission and discharge, and the correlation between nutritional risk and clinical outcomes was analyzed.

Results

A total of 413 GIST patients were included in this study, among which 114 patients had malnutrition risk at admission (NRS2002 score ≥ 3), and 65 patients had malnutrition (PG-SGA score ≥ 4). The malnutrition risk rate (27.60 vs. 46.73%, p &lt; 0.001) and malnutrition incidence (15.73 vs. 37.29%, p &lt; 0.001) at admission were lower than those at discharge. Compared with the laboratory results at admission, the albumin, prealbumin, and total protein of the patients at discharge were significantly lower (all p &lt; 0.05). And there was a negative correlation between PG-SGA and clinical outcome (all p &lt; 0.05).

Conclusion

The nutritional status of GIST patients after surgical resection at discharge was worse than that at admission, and malnutrition is an important risk factor leading to poor clinical outcomes.

Noncoding RNAs in Drug Resistance of Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor in the gastrointestinal tracts and a model for the targeted therapy of solid tumors because of the oncogenic driver mutations in KIT and PDGDRA genes, which could be effectively inhibited by the very first targeted agent, imatinib mesylate. Most of the GIST patients could benefit a lot from the targeted treatment of this receptor tyrosine kinase inhibitor. However, more than 50% of the patients developed resistance within 2 years after imatinib administration, limiting the long-term effect of imatinib. Noncoding RNAs (ncRNAs), the non-protein coding transcripts of human, were demonstrated to play pivotal roles in the resistance of various chemotherapy drugs. In this review, we summarized the mechanisms of how ncRNAs functioning on the drug resistance in GIST. During the drug resistance of GIST, there were five regulating mechanisms where the functions of ncRNAs concentrated: oxidative phosphorylation, autophagy, apoptosis, drug target changes, and some signaling pathways. Also, these effects of ncRNAs in drug resistance were divided into two aspects. How ncRNAs regulate drug resistance in GIST was further summarized according to ncRNA types, different drugs and categories of resistance. Moreover, clinical applications of these ncRNAs in GIST chemotherapies concentrated on the prognostic biomarkers and novel therapeutic targets.

Computed tomography features and clinical characteristics of gastritis cystica profunda

Background

The diagnostic evidence of gastritis cystica profunda (GCP) are not adequately described due to its extremely low morbidity. This study aimed to analyze and summarize the comprehensive CT features and clinical characteristics of patients with GCP.

Results

Nineteen patients were enrolled, including eight men and eleven women, with a mean age of 55.53 years. Only one patient had the history of gastric polypectomy. Among the nineteen cases, two cases were in the gastric cardia, four in the gastric fundus, eight in the gastric body and five in the gastric antrum. The shapes were sphere in thirteen patients, hemisphere in five patients and diffuse in one patient. The mean size of eighteen local lesions was 1.63 cm. The cystic changes in submucosa were detected in fifteen patients. Compared with the pancreas, most GCP lesions were hypo-attenuated on unenhanced CT (n = 8), in arterial phase (AP) (n = 17) and venous phase (VP) (n = 11). Fifteen patients had the peak enhancement in VP and two in AP. The rim-like enhancement with central low attenuation was clearly observed in thirteen patients. For the GCP accompanied by adenocarcinoma, the enhancement peak was present in AP and the gradual expansion of enhancement area was in VP. All patients underwent surgical or endoscopic resection. Sixteen cases had remission of symptoms and no recurrence.

Conclusions

The careful analysis of CT features and clinical characteristics can provide support for deepening the understanding of the GCP. However, a more accurate diagnosis depends on histopathological features.

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

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

Fibrinogen-like protein 2 in gastrointestinal stromal tumour

Gastrointestinal stromal tumour (GIST), the most common sarcoma of the gastrointestinal tract, can be treated effectively with tyrosine kinase inhibitors, such as imatinib. Cancer immune therapy has limited efficacy, and little is known about the immune suppressive factors in GISTs. Fibrinogen‐like protein 2 (FGL2) is expressed either as a membrane‐associated protein or as a secreted soluble protein that has immune suppressive functions. We found that GISTs expressed FGL2 mRNA highly compared to other types of cancer in a large human cancer transcriptome database. GIST expressed FGL2 frequently also when studied using immunohistochemistry in two large clinical series, where 333 (78%) out of the 425 GISTs were FGL2 positive. The interstitial cells of Cajal, from which GISTs may originate, expressed FGL2. FGL2 expression was associated with small GIST size, low mitotic counts and low tumour‐infiltrating lymphocyte (TIL) counts. Patients whose GIST expressed FGL2 had better recurrence‐free survival than patients whose GIST lacked expression. Imatinib upregulated FGL2 in GIST cell lines, and the patients with FGL2‐negative GIST appeared to benefit most from long duration of adjuvant imatinib. We conclude that GISTs express FGL2 frequently and that FGL2 expression is associated with low TIL counts and favourable survival outcomes.

Mimics and Pitfalls of Primary Ovarian Malignancy Imaging

The complex anatomy and similarity of imaging features of various pathologies in the pelvis can make accurate radiology interpretation difficult. While prompt recognition of ovarian cancer remains essential, awareness of processes that mimic ovarian tumors can avoid potential misdiagnosis and unnecessary surgery. This article details the female pelvic anatomy and highlights relevant imaging features that mimic extra-ovarian tumors, to help the radiologists accurately build a differential diagnosis of a lesion occupying the adnexa.

Genotyping guided ripretinib directly after the progression of first-line imatinib therapy in advanced gastrointestinal stromal tumor: a case report

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Surgery and tyrosine kinase inhibitor (TKI) therapy are the main choices of treatment. However, the long-term use of TKIs is prone to drug resistance. Herein, we report the case of a 47-year-old female with primary gastric GIST with liver metastases since June 2015. The patient achieved disease control under imatinib therapy and underwent primary lesion resection. She took postoperative imatinib maintenance therapy, but discontinued imatinib for 10 months about 2 years after surgery. The patient suffered from disease progression in May 2019, with recurrence of liver metastases and new abdominal metastases. From then on, imatinib was resumed and partial response (PR) persisted for another 2 years. The patient subsequently experienced tumor progression due to secondary KIT exon 17 mutation confirmed by tissue biopsy and circulating tumor DNA (ctDNA) detection. After multidisciplinary team discussion, the patient received ripretinib as a second-line therapy, and ctDNA monitoring demonstrated that the KIT mutations turned negative. After disease control from ripretinib for 2+ months, she underwent cytoreductive surgery (R0/1) and received ripretinib maintenance treatment postoperatively. We believe that this case provides a reference value for individualized ripretinib precise therapy according to mutational analysis after the progression of first-line GIST treatment, and ctDNA can predict effectiveness to guide treatment.

Development and validation of a novel diagnostic model for initially clinical diagnosed gastrointestinal stromal tumors using an extreme gradient-boosting machine

Introduction

Gastrointestinal stromal tumor (GIST) is the most common gastrointestinal soft tissue tumor. Clinical diagnosis mainly relies on enhanced CT, endoscopy and endoscopic ultrasound (EUS), but the misdiagnosis rate is still high without fine needle aspiration biopsy. We aim to develop a novel diagnostic model by analyzing the preoperative data of the patients.

Methods

We used the data of patients who were initially diagnosed as gastric GIST and underwent partial gastrectomy. The patients were randomly divided into training dataset and test dataset at a ratio of 3 to 1. After pre-experimental screening, max depth = 2, eta = 0.1, gamma = 0.5, and nrounds = 200 were defined as the best parameters, and in this way we developed the initial extreme gradient-boosting (XGBoost) model. Based on the importance of the features in the initial model, we improved the model by excluding the hematological features. In this way we obtained the final XGBoost model and underwent validation using the test dataset.

Results

In the initial XGBoost model, we found that the hematological indicators (including inflammation and nutritional indicators) examined before the surgery had little effect on the outcome, so we subsequently excluded the hematological indicators. Similarly, we also screened the features from enhanced CT and ultrasound gastroscopy, and finally determined the 6 most important predictors for GIST diagnosis, including the ratio of long and short diameter under CT, the CT value of the tumor, the enhancement of the tumor in arterial period and venous period, existence of liquid area and calcific area inside the tumor under EUS. Round or round-like tumors with a CT value of around 30 (25–37) and delayed enhancement, as well as liquid but not calcific area inside the tumor best indicate the diagnosis of GIST.

Conclusions

We developed a model to further differential diagnose GIST from other tumors in initially clinical diagnosed gastric GIST patients by analyzing the results of clinical examinations that most patients should have completed before surgical resection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-02048-1.

Prognostic significance of MCM6 expression in gastrointestinal stromal tumor

Minichromosome maintenance (MCM) proteins are essential for the initiation of DNA replication and they are prognostic markers in various human cancers. The aim of this study was to investigate the role of the MCM6 protein in gastrointestinal stromal tumor (GIST) and its clinical and prognostic significance. We evaluated MCM6 expression in 211 GIST samples using immunohistochemistry. We used the receiver operating characteristic curve (ROC) to identify optimal cut-off values. High MCM6 expression was associated with tumor size, mitosis, tumor necrosis, presence of recurrence/metastasis, and the National Institute of Health (NIH) and Armed Forces Institute of Pathology (AFIP) malignant risk criteria. Patients with high MCM6 expression had significantly shorter overall survival (OS) and disease-free survival (DFS) than those with low MCM6 expression. Univariate analysis indicated that tumor size, mitosis, AFIP and NIH malignant risk criteria, and high MCM6 expression were significantly associated with poor OS and DFS. High MCM6 expression and high-risk group categorization based on the NIH criteria were independent prognostic factors for OS and DFS. High MCM6 expression is significantly associated with tumor progression and aggressiveness and is an independent factor for shorter survival in GIST patients. MCM6 expression could be a predictive biomarker for tumor aggressiveness as well as a treatment target.

Down-regulation of SOCS6: an unfavorable prognostic factor for gastrointestinal stromal tumor proven by survival analysis

Background

Many studies reporting that down-regulation of SOCS6 plays vital roles in promoting progression of malignant tumors have been published. The present study was performed to evaluate whether SOCS6 was significantly associated with prognosis of GIST patients.

Methods

Immunohistochemical staining was accomplished to evaluate the expression levels of SOCS6 among GIST patients. The impacts of SOCS6 expression on overall survival (OS) and recurrence-free survival (RFS) of GIST patients were assessed by Cox proportional hazard regression model analysis and Kaplan-Meier curve analysis.

Results

It was demonstrated that the expression level of SOCS6 was significantly associated with tumor size (P=0.001). Then according to Kaplan-Meier curve analysis, low expression of SOCS6 was significantly correlated with worse OS and RFS of GIST patients. Ultimately, it was revealed by Cox proportional regression model analysis that low expression of SOCS6 was an independent predictive factor for OS and RFS.

Conclusions

Low expression of SOCS6 was an independent prognostic factor for GIST, suggesting its potential as a novel biomarker predicting survival of GIST patients.

National Utilization of Imatinib in the Management of Resected Gastrointestinal Stromal Tumors

BACKGROUND

Imatinib decreases recurrence risk and improves overall survival (OS) in localized gastrointestinal stromal tumors (GISTs); however, the extent to which patients receive appropriate treatment in the US has not been well characterized.

METHODS

Patients with non-metastatic, resectable GIST were included in this study (National Cancer Database, 2010-2015). Those with a low-risk of recurrence were classified as receiving overtreatment or guideline-concordant treatment, while those with a high-risk of recurrence were classified as receiving undertreatment or guideline-concordant treatment. Multivariable logistic regression was used to determine factors associated with non-concordant treatment. The association between non-concordant treatment and OS was evaluated using multivariable Cox regression and propensity score matching.

RESULTS

Among 3088 patients with high-risk GIST, 41% were undertreated, and among 3908 patients with low-risk GIST, 18.8% were overtreated. For patients with high-risk GIST, age > 60 years, African American race, and treatment at a community or comprehensive cancer program were associated with undertreatment. Among low-risk patients, small bowel primary, tumor size > 2 cm, and tumors with > 1 mitotic figure per 50 high-power fields were more likely to be overtreated. After propensity score matching, guideline-concordant therapy was associated with an 8.8% improvement in 5-year OS (81.9% vs. 73.1%, p = 0.002) for those with high-risk GIST and decreased risk of death (hazard ratio 0.63, 95% confidence interval 0.47-0.84). There was no statistically significant difference in survival for patients with low-risk GIST with the addition of imatinib overtreatment (overtreatment 93.9% vs. 89.6%, p = 0.053).

CONCLUSIONS

Nearly 30% of GIST patients do not receive guideline-concordant treatment and future work is needed to understand the factors driving non-concordant treatment.

Review: Challenges of In Vitro CAF Modelling in Liver Cancers

Simple Summary

Liver cancer and tumours spreading from other organs to the liver are associated with high death rates. Current treatments include surgical removal of the tumour and chemotherapy. Unfortunately, patients are often re-diagnosed with liver nodules in the years after cessation of the treatment. Therefore, scientists are looking for alternative treatment strategies, and these include targeting the tumour environment. The tumour environment includes the cancer-associated fibroblasts, which could be an interesting target for therapy in combination with current strategies. In this review paper we summarize the current models to investigate the effect of the tumour on the cancer-associated fibroblasts. Not many studies focus on the cancer-associated fibroblasts in non-animal models and this should improve in order to better understand the role of the cancer-associated fibroblasts and to evaluate the potential of cancer-associated fibroblast-directed therapies.

Abstract

Primary and secondary liver cancer are the third cause of death in the world, and as the incidence is increasing, liver cancer represents a global health burden. Current treatment strategies are insufficient to permanently cure patients from this devastating disease, and therefore other approaches are under investigation. The importance of cancer-associated fibroblasts (CAFs) in the tumour microenvironment is evident, and many pre-clinical studies have shown increased tumour aggressiveness in the presence of CAFs. However, it remains unclear how hepatic stellate cells are triggered by the tumour to become CAFs and how the recently described CAF subtypes originate and orchestrate pro-tumoural effects. Specialized in vitro systems will be needed to address these questions. In this review, we present the currently used in vitro models to study CAFs in primary and secondary liver cancer and highlight the trend from using oversimplified 2D culture systems to more complex 3D models. Relatively few studies report on the impact of cancer (sub)types on CAFs and the tumour microenvironment, and most studies investigated the impact of secreted factors due to the nature of the models.

Identification of New Tumor-Related Gene Mutations in Chinese Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. As the main GIST drivers, gain-of-function mutations in KIT or PDGFRA are closely associated with not only tumor development and progression but also therapeutic response. In addition to the status of KIT and PDGFRA, little is known about other potential GIST-related genes. In this study, we identified the mutation profiles in 49 KIT-mutated GIST tumors using the whole exome sequencing (WES) method. Furthermore, some representative mutations were further validated in an independent GIST cohort using the SNaPshot SNP assay. We identified extensive and diverse mutations of KIT in GIST, including many undescribed variants. In addition, we revealed some new tumor-related gene mutations with unknown pathogenicity. By enrichment analyses of gene function and protein-protein interaction network construction, we showed that these genes were enriched in several important cancer- or metabolism-related signaling pathways, including PI3K-AKT,RTK-RAS, Notch, Wnt, Hippo, mTOR, AMPK, and insulin signaling. In particular, DNA repair-related genes, including MLH1, MSH6, BRCA1, BRCA2, and POLE, are frequently mutated in GISTs, suggesting that immune checkpoint blockade may have promising clinical applications for these GIST subpopulations. In conclusion, in addition to extensive and diverse mutations of KIT, some genes related to DNA-repair and cell metabolism may play important roles in the development, progression and therapeutic response of GIST.

Association Between the Nutritional Risk and the Survival Rate in Newly Diagnosed GIST Patients

Background: Currently, the incidence of gastrointestinal stromal tumors (GIST) is increasing rapidly worldwide. Malnutrition may increase the risk of perioperative complications and affect the prognosis of patients. However, previous studies on the nutritional status of GIST patients and its impact on prognosis are limited. Therefore, this study aims to explore the incidence of malnutrition in newly diagnosed GIST patients, the proportion of participants in need of nutritional intervention, and the relationship between nutritional status and overall survival (OS). Methods: We retrospectively analyzed the clinical data of GIST patients treated in our hospital from January 2014 to January 2018. Nutritional Risk Screening 2002 (NRS2002) and Patient-Generated Subjective Global Assessment (PG-SGA) were used to assess the nutritional status of all patients. This study was to investigate the clinical significance of PG-SGA by analyzing the relationship between PG-SGA score and OS. Results: A total of 1,268 newly diagnosed GIST patients were included in this study, of which 77.76% were at risk of malnutrition (NRS2002 score ≥ 3), and the incidence of malnutrition was 10.09% (PG-SGA score ≥ 4). Meanwhile, we found 2.29% of the patients required urgent nutritional support (PG-SGA score ≥ 9). Multivariate analysis showed that age (p = 0.013), BMI (p = 0.001), weight loss (p = 0.001), anemia (p = 0.005), pre-albumin (p = 0.010), albumin (p = 0.002), tumor location (p = 0.001), tumor size (p = 0.002), and NIH classification (p = 0.001) were risk factors for nutritional status. The prognosis was significantly in GIST patients with different PG-SGA score at admission (p < 0.05). Conclusion: This study suggested that malnutrition is common in newly diagnosed GIST patients, and the higher the PG-SGA score, the worse the clinical outcome.

Unusual Presentation of a Gastrointestinal Stromal Tumor in a Small Intestine Diverticulum

A 50-year-old female with no significant medical history initially presented to an urgent care center with symptoms of acute onset abdominal pain, nausea, and emesis. Chest and abdominal X-ray revealed free air under the diaphragm, prompting immediate transfer to the emergency department. Continued abdominal tenderness and pain were concerning for perforated viscus. The patient was transferred to the operating room, and diagnostic laparoscopy was performed. Inflammation and contamination were discovered in the right side of the abdomen and pelvis secondary to a small bowel (SB) perforation. Segmental SB resection revealed a perforated diverticulum. Pathological examination confirmed a diagnosis of gastrointestinal stromal tumor (GIST) at the perforated segment. On postoperative day 5, the patient was discharged home, and at 30-month follow-up, the patient continued to do well. Although rare, SB diverticula are commonly false (i.e., pseudodiverticula). The concomitant presence of a GIST in a true SB diverticulum presenting with perforation has not yet been reported.

A proposed risk assessment score for gastrointestinal stromal tumors based on evaluation of 19,030 cases from the National Cancer Database

BACKGROUND

Standard risk assessment algorithms for gastrointestinal stromal tumor (GIST) are based on anatomic and histopathological variables with arbitrarily defined subcategories. Our goal was to improve risk assessment for GIST through retrospective analysis of patient data.

METHODS

The National Cancer Database (NCDB) was queried for patients with GIST; the final cohort consisted of 19,030 cases. Main outcomes were metastasis at presentation and overall survival. A test dataset was used to reevaluate risk stratification parameters in multivariate regression models. A novel risk assessment system was applied to the validation dataset and compared to other currently used risk assessment schemes.

RESULTS

Analysis of observed prevalence of metastases at presentation suggested 7 cm and mitotic rates > 10 per 5 mm² as optimal threshold values. A proposed risk stratification score showed statistical superiority compared to the National Comprehensive Cancer Network, American Joint Committee on Cancer, and modified National Institute of Health classifications in predicting probability of presentation with metastasis at diagnosis and 4-year overall survival after accounting for important covariables including patient age and comorbidities, year of diagnosis, and surgical/systemic therapeutic regimen.

CONCLUSIONS

Reexamination of prognostic factors for GIST demonstrated that current threshold values for tumor size and mitotic rate are suboptimal. A risk stratification score based on revised categorization of these factors outperformed currently used risk assessment algorithms.

[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.

Contributions of NFKB1 -94insertion/deletion ATTG polymorphism to the susceptibility of gastrointestinal cancers: A meta-analysis

Nuclear factor‐kappa B1 (NF‐κB1), a pleiotropic transcription factor, functions as a critical contributor to tumorigenesis. Growing numbers of case‐control studies were carried out to analyse the potential contribution of NF‐κB1 gene variants to gastrointestinal cancer risk, yet remains conflicting conclusions. Therefore, we conducted this most up‐to‐date meta‐analysis to evaluate the relationship between NF‐κB1 gene insertion (I)/deletion (D) polymorphism, namely −94ins/delATTG or rs28362491, and the susceptibility to gastrointestinal cancers. We searched PubMed, EMBASE and MEDLINE databases updated in April 2021 for relevant studies. Meta‐analysis was carried out by software Stata11.0. The quantification of the relationship was determined by computing the combined odds ratios (ORs) and their corresponding 95% confidence intervals (CIs). Sensitivity analysis, the funnel plot and Begg's rank correlation test were also applied. Our findings indicate that −94ins/delATTG polymorphism could not significantly impact the susceptibility to gastrointestinal cancers. Under any five genetic models, −94ins/delATTG polymorphism was not remarkedly linked to the risk of colorectal, gastric and oesophageal cancer, respectively. The significant role of −94ins/delATTG was only observed in some certain subgroups. Findings here suggest that NF‐κB1 gene −94ins/delATTG polymorphism may not predispose to gastrointestinal cancer susceptibility.

Imatinib Regulates miR-483-3p and Mitochondrial Respiratory Complexes in Gastrointestinal Stromal Tumors

Metabolic adaptation to increased oxidative phosphorylation (OXPHOS) has been found in gastrointestinal stromal tumor (GIST) upon imatinib treatment. However, the underlying mechanism of imatinib-induced OXPHOS is unknown. Discovering molecules that mediate imatinib-induced OXPHOS may lead to the development of therapeutic strategies synergizing the efficacy of imatinib. In this study, we explored the role of microRNAs in regulating OXPHOS in GIST upon imatinib treatment. Using a microarray approach, we found that miR-483-3p was one of the most downregulated miRNAs in imatinib-treated tumors compared to untreated tumors. Using an extended series of GIST samples, we further validated the downregulation of miR-483-3p in imatinib-treated GIST samples by RT-qPCR. Using both gain- and loss-of-function experiments, we showed that miR-483-3p could regulate mitochondrial respiratory Complex II expression, suggesting its role in OXPHOS regulation. Functionally, miR-483-3p overexpression could rescue imatinib-induced cell death. These findings provide the molecular link for imatinib-induced OXPHOS expression and the biological role of miR-483-3p in regulating cell viability upon imatinib treatment.

New FDA oncology small molecule drugs approvals in 2020: Mechanism of action and clinical applications

In 2020, fifty-three new drugs, including forty small-molecules (thirty-six new chemical entities and four new diagnostic agents) and thirteen biologic drugs were approved by the U.S. Food and Drug Administration (FDA). This year, small-molecules continue to play a role in innovative treatments representing around 75% of all drugs accepted by FDA. The dominant therapeutic area was oncology, accounting for twenty-three new approvals, including thirteen new chemical entities, four new diagnostic agents, and thirteen biologic drugs. Recognizing the importance of small-molecules on cancer treatment, this review aims to provide an overview regarding the clinical applications and mechanism of action of the thirteen new small-molecules (excluding new diagnostic agents) approved by FDA in 2020.

The Value of Endoscopic Ultrasonography in the Endoscopic Resection of Gastrointestinal Stromal Tumors

Objective

This study aimed to explore the clinical value of endoscopic ultrasonography (EUS) in the endoscopic resection of gastrointestinal stromal tumors (GISTs).

Methods

A retrospective study of 92 patients who were confirmed to have GISTs by endoscopic resection after EUS examination was conducted. The preoperative features of the EUS examination, ultrasound diagnosis, endoscopic resection methods, surgical procedures, complications, and complete degree of lesion resection were recorded. And 16 patients who were diagnosed by endoscopy and EUS and confirmed by surgical operation were included and analyzed in the subsequent part of the investigation (gastroscopy and EUS image analysis, EUS image and risk classification).

Results

The preoperative diagnosis rate of EUS and postoperative pathological diagnosis of GISTs was 78.7% (85/108), and the presence of a non-homogeneous echo and liquid anechoic zone in GISTs often indicated higher risk (P < 0.05). There was a positive correlation between tumor size and risk (P < 0.05).

Conclusion

The endoscopic resection of GISTs is feasible and safe. EUS is of great significance for the diagnosis and risk assessment of GISTs and can assist in the endoscopic resection of GISTs.

RP11-616M22.7 recapitulates imatinib resistance in gastrointestinal stromal tumor

Emerging evidence has shown that long non-coding RNAs (lncRNAs) play crucial roles in human cancers. However, systematic characterization of lncRNAs and their roles in gastrointestinal stromal tumor (GIST) therapy have been lacking. We performed high-throughput RNA sequencing (RNA-seq) of 20 GIST and paired adjacent normal samples. We characterized the transcriptional landscape and dysregulation of lncRNAs in GIST. We identified 866 upregulated and 1,268 downregulated lncRNAs in GIST samples, the majority of which were GIST-specific over other cancer types. Most hallmarks were found to be dysregulated in GIST samples, and lncRNAs were highly associated with cancer-related hallmarks. RP11-616M22.7 was identified to increase in imatinib-resistant samples compared to those in non-resistant samples. Further analysis revealed that RP11-616M22.7 was closely associated with the Hippo signaling pathway. By treating GIST cells with different doses of imatinib, we verified that RP11-616M22.7 knockdown promotes the sensitivity of tumor cells, whereas RP11-616M22.7 overexpression induces resistance to imatinib. We further confirmed reducing of resistance to imatinib by knocking down RP11-616M22.7 in vivo. Additionally, RP11-616M22.7 was observed to interact with RASSF1 protein. Our study revealed that deficiency of RP11-616M22.7 was able to reduce resistance of the GIST cell response to imatinib treatment both in vitro and in vivo.

Classification and Treatment of Diseases in the Age of Genome Medicine Based on Pathway Pathology

The focus of pathology as a biomedical discipline is the identification of the pathomechanisms of diseases and the integration of this knowledge into routine diagnosis and classification. Standard tools are macroscopic and microscopic analysis complemented by immunohistochemistry and molecular pathology. So far, classification has been based on the paradigm of cellular pathology established by Rudolf Virchow and others more than 150 years ago, stating that diseases originate from diseased cells. This dogma is meanwhile challenged by the fact that cells can be fully reprogrammed. Many diseases are nowadays considered to originate from undifferentiated stem cells, induced into a diseased state by genetic or epigenetic alterations. In addition, the completion of the Human Genome Project, with the identification of more than 20.000 genes and a much higher number of gene variants and mutations, led to the concept that diseases are dominated by genetics/epigenetics rather than cells of origin. The axiom of cellular pathology, however, still holds true, as cells are the smallest animate units from which diseases originate. Medical doctors and researchers nowadays have to deal with a tremendous amount of data. The International Classification of Diseases will expand from 14.400 entities/codes in ICD-10 to more than 55.000 in ICD-11. In addition, large datasets generated by “genomics“, e.g., whole-genome sequencing, expression profiling or methylome analysis, are meanwhile not only applied in research but also introduced into clinical settings. It constitutes a major task to incorporate all the data into routine medical work. Pathway pathology may help solve this problem. It is based on the realization that diseases are characterized by three essential components: (i) cells of origin/cellular context and (ii) the alteration of cellular as well as (iii) molecular/signal transduction pathways. The concept is illustrated by elaborating on two key cellular pathways, i.e., the cellular senescence of normal cells and the immortality of cancer cells, and by contrasting single cell/single pathway diseases, such as mycoplasma and coughing pneumonia, with complex diseases such as cancer, with multiple cell types as well as multiple affected cellular and signaling pathways. Importantly, the concept of pathway pathology is not just intended to classify disease, but also to conceive new treatment modalities. This article is dedicated to Dr. Leonard Hayflick, who made basic discoveries in pathway pathology not only by identifying cells causing disease (Mycoplasma pneumoniae) and establishing cell strains for treating disease (WI-38 for viral vaccines), but also by first describing cellular senescence and immortality.

A multidisciplinary approach in the diagnostic challenge of GIST

Gastrointestinal stromal tumors (GISTs) are the most common malignant mesenchymal lesions of the gastrointestinal tract. They originate from the interstitial cells of Cajal and are characterized by overexpression of the tyrosine kinase receptor, protein product of c-KIT gene (KIT). In this retrospective study, conducted over a period of 10 years, we retrieved from our database, a total number of 57 patients, admitted and operated in the surgical department of ‘Sf. Pantelimon’ Emergency Clinical Hospital, Bucharest, for digestive tumors, histopathologically confirmed as GISTs. More than half of the cases presented as surgical emergencies and the tumors found during the surgical procedures, which proved to be GISTs, were sometimes difficult to differentiate from other mesenchymal tumors, both for the clinician and the pathologist. The diagnosis of GIST relies mostly on pathology and immunohistochemistry, but also on clinical and imagistic data. The most common emergencies were digestive hemorrhage (associated with gastric location), followed by intestinal obstruction (especially for the ileal localization). The largest dimensions corresponded to gastric location. For selected indications (upper digestive sites), upper digestive endoscopy approaches 100% sensitivity. This study focuses on diagnosis of GISTs sustained by both clinical and imagistic methods, along with histopathology and immunohistochemistry techniques, according to the World Health Organization 2019 criteria. Even though the differential diagnosis of these tumors is challenging, an interdisciplinary cooperation with a multiple approach increases the odds of a correct positive diagnosis.

Concomitant use of Tyrosine-kinase Inhibitor and Mepolizumab in Asthma secondary to Chronic Myeloid Leukemia with hypereosinophilia

INTRODUCTION

Asthma and hypereosinophilia have been treated with different therapeutics in the past. Some of them appear to be more effective in symptoms resolution and decreasing eosinophilic count.

CASE PRESENTATION

We report here an unusual case of asthma with hypereosinophilia secondary to Chronic Myeloid Leukemia (CML) with high prevalence of eosinophilic infiltrate, treated simultaneously with an anti-IL-5 antibody (Mepolizumab) and Tyrosine-kinase Inhibitors (TKI: Imatinib and Bosutinib) for three years. The patient showed a promising reduction of pulmonary exacerbations and good control of CML without developing side effects.

CONCLUSION

We hope that this finding could inspire further studies on the efficacy and safety of the concomitant use of anti-IL-5 and TKI.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Delayed adjuvant imatinib in patients with high risk of recurrence of gastrointestinal stromal tumor after radical surgery: a retrospective cohort study

PURPOSE

To investigate the impact of delayed adjuvant imatinib on GIST patients with high risk of recurrence.

METHOD

Adult GIST patients were retrospectively collected from our hospital between 2011 and 2018, and patients having high risk of recurrence were included for subsequent analyses. The primary endpoint was recurrence-free survival (RFS).

RESULTS

According to the interval between the radical surgery and the beginning of adjuvant imatinib, 222 patients were divided into three groups: group A (≤ 2 months, n = 41), group B (2-≤ 4 months, n = 113), and group C (4-≤ 6 months, n = 68). Univariate, multivariate, and survival analyses all showed that patients in group A had significantly more favorable RFS than those in group C but not group B, and patients taking adjuvant imatinib for over 12 months were also associated with longer RFS comparing to adjuvant imatinib of ≤ 12 months. When stratified by the duration of adjuvant imatinib, no significant differences were found in RFS among groups A, B, and C for adjuvant imatinib of ≤ 12 months. While for adjuvant imatinib of over 12 months, both groups A and B had significantly more favorable RFS than group C, and no significant difference in RFS was found between group A and B.

CONCLUSION

Delayed postoperative adjuvant imatinib for over 4 months in patients with high risk of recurrence of GIST may lead to worse RFS, and longer treatment with shorter delay has best results.

Antitumor efficacy of CHMFL-KIT-110 solid dispersion in mouse xenograft models of human gastrointestinal stromal tumors

PURPOSE

CHMFL-KIT-110, a selective c-KIT kinase inhibitor for gastrointestinal stromal tumors (GISTs), possesses a poorly water-soluble, limiting the further development of the drug. This study was to investigate the antitumor efficacy of CHMFL-KIT-110 and CHMFL-KIT-110 solid dispersion (laboratory code: HYGT-110 SD) in GIST tumor xenograft models and to explore the PK/PD relationship of HYGT-110 SD.

METHODS

Plasma concentrations of HYGT-110 and HYGT-110 SD were determined by LC-MS/MS in KM mice. Antitumor activity was evaluated by measuring tumor volume and weight in c-KIT-dependent GIST xenograft models. PK/PD relationship was assessed by LC-MS/MS and Western Blot in the GIST-T1 xenografted mice.

RESULTS

HYGT-110 exhibited a low oral bioavailability (10.91%) in KM mice. Compared with HYGT-110 treatment, the C_max and AUC_0-t of HYGT-110 SD in mice plasma were substantially increased by 18.81 and 6.76-fold, respectively. HYGT-110 SD (10, 30, and 100 mg/kg/day) also could dose-dependently decrease the tumor volume and weight in the GIST-882 cell-inoculated xenograft mouse models and show 86.35% tumor growth inhibition (TGI) at 28 days at a 25 mg/kg bid dosage in the GIST-T1 cell-inoculated xenograft mouse model. The free concentration of HYGT-110 in plasma was closely correlated with the inhibition of c-KIT phosphorylation levels in tumor tissues.

CONCLUSIONS

In comparison with the HPMC formulation, both improved PK and PD characteristics of the solid dispersion formulation of CHMFL-KIT-110 were observed in in vivo animal experiments.

The Role of lncRNA PCAT6 in Cancers

Long non-coding RNA (lncRNA) PCAT6 is a member of the Prostate Cancer Associated Transcripts family of molecules. In this review, we focus on the latest studies involving PCAT6 in the diagnosis, treatment, and prognosis of malignant tumors of the digestive, respiratory, urinary, reproductive, motion, and nervous systems. PCAT6 was found to be highly expressed in gastric cancer, colon cancer, hepatocellular carcinoma, lung cancer, bladder cancer, ovarian cancer, breast cancer, cervical cancer, osteosarcoma, glioblastoma, and other tumors. PCAT6 can promote the development and progression of different types of malignant tumors through various mechanisms. Overall, these findings suggest that PCAT6 may play an increasingly vital role in the clinical assessment of these malignant tumors. It can function as an oncogene and may be used as a potential new prognostic biomarker of these tumors.