The standard diagnosis, treatment, and follow-up of gastrointestinal stromal tumors based on guidelines

A preoperative risk prediction model for high malignancy potential gastrointestinal stromal tumors of the stomach

BACKGROUND

Gastric gastrointestinal stromal tumors (GISTs) exhibit various degrees of aggression and malignant potential. However, no systematic preoperative evaluation strategy to predict the malignancy potential of gastric GISTs has yet been developed. This study aimed to develop a reliable and easy-to-use preoperative risk-scoring model for predicting high malignancy potential (HMP) gastric GISTs.

METHODS

The data of 542 patients with pathologically confirmed gastric GISTs who underwent resection were reviewed. Multivariate logistic regression analysis was used to identify significant predictors of HMP. The risk-scoring system (RSS) was based on the predictive factors for HMP, and its performance was validated using a split-sample approach.

RESULTS

A total of 239 of 542 (44.1%) surgically resected gastric GISTs had HMP. Multivariate analysis demonstrated that tumor size, location, and surface changes were independent risk factors for HMP. Based on the accordant regression coefficients, the presence of surface ulceration was assigned 1 point. Tumor sizes of 4-6 cm and > 6 cm were assigned 2 and 5 points, respectively. Two points were assigned to cardia or fundus locations. A score of 3 points was the optimal cut-off value for HMP prediction. HMP were found in 19.8% and 82.7% of the low and high-risk groups of the RSS, respectively. The area under the receiver-operating characteristic curve for predicting HMP was 0.81 (95% confidence interval (CI) 0.75-0.86). Discrimination was good after validation (0.75, 95% CI 0.69-0.81).

CONCLUSION

This simple RSS could be useful for predicting the malignancy potential of gastric GISTs and may aid preoperative clinical decision making to ensure optimal treatment.

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

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

Contribution of Interstitial Cells of Cajal to Gastrointestinal Stromal Tumor Risk

BACKGROUND Gastrointestinal stromal tumors (GISTs), which originate from interstitial cells of Cajal (ICCs), are one of most common mesenchymal tumors of the gastrointestinal tract. This study explored the impact of ICCs and immunological markers on GIST risk. MATERIAL AND METHODS A total of 122 patients diagnosed with GISTs who underwent surgery were recruited for the study. Demographic and clinical information, including modified NIH criteria, sex, age, tumor site, and tumor size, of all patients were collected. GIST risk was assessed using the modified NIH risk classification for primary GISTs. Paraffin-embedded GIST specimens were evaluated by hematoxylin-eosin staining and ICCs immunohistochemistry. RESULTS According to the modified NIH criteria, most GIST cases (44 cases, 36.07%) were at very low risk. Females had greater incidence of high-risk GISTs (P<0.05). The mean age at GIST diagnosis was 58.69±9.90 years and had no impact on GIST risk (P>0.05). Most GISTs were located in the stomach (87 cases, 71.73%), and the size of the tumors varied (0.5-20 cm). CD117/c-kit and CD34 were specific immuno-markers for ICCs and GIST. Most patients with GIST were CD117-positive (115 cases, 94.26%), 111 cases (90.98%) were CD34-positive, and 109 cases (89.34%) were positive for both CD117/c-kit and CD34. With increasing GIST risk, CD117 (also named c-k0it) and CD34 expression levels increased, as well as the number of ICCs (all P<0.05). CONCLUSIONS ICCs have a great impact on GISTs incidence. CD117/c-kit and CD34 expression, as well ICCs levels, appear to affect GIST risk.

Systematic Endoscopic Approach for Diagnosing Gastric Subepithelial Tumors

Subepithelial tumors (SETs) are commonly encountered during upper gastrointestinal endoscopy, especially during national gastric cancer screening programs in Korea. Although the majority of SETs are benign, endoscopists harbor concerns regarding whether a SET is benign or malignant because the diagnosis cannot be established on the basis of routine endoscopic biopsy findings. The differential diagnosis of SETs is important, beginning with meticulous endoscopic examination, including the evaluation of the location, macroscopic shape, color, surface characteristics, mobility, consistency, and size of the tumors. The yield of endoscopic biopsy increases with the use of the bite-on-bite technique for SETs without the rolling or tenting sign, with large openings, and with erosion or ulceration. In this review, a systematic approach for the diagnosis of gastric SETs during conventional endoscopy is introduced.

Relation Prediction of Co-Morbid Diseases Using Knowledge Graph Completion

Co-morbid disease condition refers to the simultaneous presence of one or more diseases along with the primary disease. A patient suffering from co-morbid diseases possess more mortality risk than with a disease alone. So, it is necessary to predict co-morbid disease pairs. In past years, though several methods have been proposed by researchers for predicting the co-morbid diseases, not much work is done in prediction using knowledge graph embedding using tensor factorization. Moreover, the complex-valued vector-based tensor factorization is not being used in any knowledge graph with biological and biomedical entities. We propose a tensor factorization based approach on biological knowledge graphs. Our method introduces the concept of complex-valued embedding in knowledge graphs with biological entities. Here, we build a knowledge graph with disease-gene associations and their corresponding background information. To predict the association between prevalent diseases, we use ComplEx embedding based tensor decomposition method. Besides, we obtain new prevalent disease pairs using the MCL algorithm in a disease-gene-gene network and check their corresponding inter-relations using edge prediction task.

A Case of Liver Metastasis from Small Intestinal Gastrointestinal Stromal Tumor 25 Years after Surgery including Autopsy Findings

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor in the digestive tract. Recurrences may occur even after radical resection; however, recurrence later than 10 years after surgery is rare. We report a case of GIST with recurrence of liver metastasis 25 years after surgery. A 56-year-old man complained of sudden epigastric pain and was transferred to the emergency department. He had undergone partial resection of the small intestine for leiomyosarcoma 25 years previously. Abdominal computed tomography showed multiple liver tumors with massive hemorrhage. Ultrasound-guided percutaneous biopsy was performed for the 15-mm hepatic tumor in segment 2. Pathological findings revealed proliferation of spindle-shaped atypical cells, and immunostaining for c-kit and CD34 was both positive; the patient was therefore diagnosed with GIST. He then underwent chemotherapy for 7 years but died of multiple organ failure due to GIST. Autopsy revealed GIST occupying the entire liver with peritoneal dissemination, and minute lung metastases that could not be identified by CT were also detected. This case is interesting in considering the recurrence of GIST, and we will report it together with the literature review.

Clinical significance of surgical intervention for imatinib-resistant gastrointestinal stromal tumors in the era of multiple tyrosine kinase inhibitors

PURPOSE

Imatinib is the standard treatment for unresectable and metastatic GIST. In the late stages, patients undergoing imatinib show drug resistance. Surgical intervention has been occasionally performed for resistant lesions. However, the clinical significance of such intervention remains unclear.

METHODS

Between 2006 and 2015, 37 patients were diagnosed with imatinib-resistant GISTs. We performed surgical intervention only for localized resistant lesions. We retrospectively investigated the background characteristics, data on surgical intervention and subsequent treatment, progression-free survival (PFS), and overall survival (OS).

RESULTS

Eighteen patients diagnosed with localized resistance received surgical intervention (S-group) and 19 patients diagnosed with generalized resistance were received other TKIs (M-group). In S-group, no serious complications occurred, and all patients restarted imatinib after resection. The median PFS was 14.5 months. Five patients underwent surgical intervention multiple times followed by the continuation of imatinib, and the median duration of imatinib continuation was 22.2 months. Second-line TKIs were administered to 93% of the patients and the dose-intensity and outcome were similar in both groups. The median OS was 47.2 months after surgery.

CONCLUSIONS

Surgical intervention could be performed safely and therefore could be followed by the continuation of TKI therapy. Surgical intervention based on the appropriate criteria of resistance might thus be useful for imatinib-resistant GISTs.

Duodenal gastrointestinal stromal tumors: A retrospective study based on a 13 years experience of a single center in China

AIM

Duodenal gastrointestinal stromal tumors (GISTs) constitute a small rare subset. This study aims to analyze the prognostic differences between duodenal and jejunoileal GISTs and evaluate the clinical treatment and prognostic characteristics of patients with duodenal GISTs.

METHODS

Data of patients with primary duodenal or jejunoileal GISTs were collected. Patients were matched through propensity score matching (PSM). Perioperative and long-term outcomes of patients with duodenal GISTs were compared based on surgical approach.

RESULTS

Altogether, 101 duodenal and 219 jejunoileal GISTs were identified. In patients with duodenal GISTs, 79 (78%) underwent local resection (LR) and 22 (22%) underwent pancreaticoduodenectomy (PD). Patients undergoing PD had a longer postoperation stay (18.5 vs 13 days, P = 0.001) and more complications (Clavien-Dindo I-II complications for PD vs LR, 31.8 vs 15.2%; Clavien-Dindo III-V complications for PD vs LR, 22.7 vs. 2.5%; P < 0.001). There was no difference in recurrence-free survival (RFS) (P = 0.8) or overall survival (OS) (P = 0.9) when comparing patients who underwent LR versus PD. Multivariable analysis showed that tumor size >5 cm was the only independent predictor of shorter RFS (P = 0.004) and OS (P = 0.012). After matching, there was no significant difference in RFS and OS between patients with duodenal versus jejunoileal GISTs (both P > 0.05).

CONCLUSION

The prognosis of duodenal and jejunoileal GISTs are similar. Recurrence and OS of duodenal GISTs primarily depend on tumor size. For duodenal GISTs, LR is associated with comparable long-term survival when compared to PD, but with superior short-term outcomes.

Extragastrointestinal Stromal Tumor Presenting as a Recurrent Vaginal Mass: Case Report

Gastrointestinal stromal tumors (GISTs) are the dominant mesenchymal tumors of the digestive tract. Extragastrointestinal stromal tumors (EGISTs) usually originate outside the gastrointestinal tract without connection to the gastric or intestinal wall. However, EGISTs arising from the vaginal wall are very rare. Here, we report a case of EGIST that occurred in the vagina of a 60-year-old woman. The tumor was present in the posterior vaginal wall. It was surgically excised, and histological examination revealed spindle cell morphology with up to 14 mitoses per 50 high power field (HPF) and necrosis with the tumor-negative margins. Immunohistochemical analyses showed strongly positive CD34, CD117, and DOG-1 expression, but negative SMA, S-100, CD10, desmin, and actin expression. The patient underwent surgery and is currently being followed up. A literature review of EGSTs and treatments is also discussed in this report.

Significance of Primary Malignant Tumors on the Outcome of Patients With Resected Gastrointestinal Stromal Tumors

AIM

This study aimed to clarify the significance of primary malignant tumors for the outcome of resected gastrointestinal stromal tumors (GISTs).

PATIENTS AND METHODS

The medical history, pathological findings and prognosis of 66 patients with GISTs resected at our institute between January 2003 and December 2018 were investigated retrospectively and compared statistically.

RESULTS

Among 66 patients with GISTs, 24 (36%) had concomitant malignant tumors. In an average study period of 57 months, one patient died from GIST, seven from other malignant tumors, and one from another disease. Only coexistence of GIST and other malignant tumors was recognized as a prognostic factor. Increasing age was significantly correlated with other malignant tumor in combination with GIST. When comparing patients with GIST alone and GIST with other malignant tumors, the latter showed significantly poorer prognosis.

CONCLUSION

Coexistence of other malignant tumors was commonly observed in patients with GIST, and was associated with poorer prognosis. This association should be carefully considered and monitored in patients with GISTs.

Pretreatment Tumor DNA Sequencing of KIT and PDGFRA in Endosonography-Guided Biopsies Optimizes the Preoperative Management of Gastrointestinal Stromal Tumors

BACKGROUND

Neoadjuvant tyrosine kinase inhibitor (TKI) therapy increases the chance of organ-preserving, radical resection in selected patients with gastrointestinal stromal tumors (GISTs). We aimed to evaluate systematic, immediate DNA sequencing of KIT and PDGFRA in pretreatment GIST tissue to guide neoadjuvant TKI therapy and optimize preoperative tumor response.

METHODS

All patients who were candidates for neoadjuvant therapy of a suspected GIST [the study cohort (SC)] were prospectively included from January 2014 to March 2018. Patients were subjected to pretreatment endosonography-guided fine-needle biopsy (EUS-FNB) or transabdominal ultrasound-guided needle biopsy (TUS-NB), followed by immediate tumor DNA sequencing (< 2 weeks). A historic (2006-2013) reference cohort (RC) underwent work-up without sequencing before neoadjuvant imatinib (n = 42). The rate of optimal neoadjuvant therapy (Therapy_OPTIMAL) was calculated, and the induced tumor size reduction (Tumor Regression_MAX, %) was evaluated by computed tomography (CT) scan.

RESULTS

The success rate of pretreatment tumor DNA sequencing in the SC (n = 81) was 77/81 (95%) [EUS-FNB 71/74 (96%); TUS-NB 6/7 (86%)], with mutations localized in KIT (n = 58), PDGFRA (n = 18), or neither gene, wild type (n = 5). In patients with a final indication for neoadjuvant therapy, the Therapy_OPTIMAL was higher in the SC compared with the RC [61/63 (97%) versus 33/42 (79%), p = 0.006], leading to a significantly higher Tumor Regression_MAX in patients treated with TKI (27% vs. 19%, p = 0.015).

CONCLUSIONS

Pretreatment endosonography-guided biopsy sampling followed by immediate tumor DNA sequencing of KIT and PDGFRA is highly accurate and valuable in guiding neoadjuvant TKI therapy in GIST. This approach minimizes maltreatment with inappropriate regimens and leads to improved tumor size reduction before surgery.

Novel Prognostic Nomogram for Recurrence-Free Survival of Patients With Primary Gastrointestinal Stromal Tumors After Surgical Resection: Combination of Prognostic Nutritional Index and Basic Variables

Background

Gastrointestinal stromal tumor (GIST) is the most common type of mesenchymal tumors in the digestive tract, often recrudescing even after R0 resection. Adjuvant tyrosine kinase inhibitor therapy prolonged recurrence-free survival (RFS). This study aimed to develop a novel nomogram for predicting the RFS of patients following surgical resection of GISTs.

Methods

Clinicopathologic data of patients with GISTs at Tianjin Medical University General Hospital (Tianjin, China) from January 2000 to October 2019 were retrospectively reviewed. Univariate and multivariate Cox regression analyses were used to select the suitable variables from the training cohort to construct a nomogram for 2- and 5-year RFS. The 1,000 bootstrap samples and calibration curves were used to validate the discrimination of the nomogram. The receiver operating characteristic analysis(ROC) was used to compare the predictive ability of the nomogram and present four commonly used risk stratification systems: National Institutes of Health (NIH)–Fletcher staging system; NIH–Miettinen criteria; Modified NIH criteria; and Air Forces Institute of Pathology risk criteria (AFIP).

Results

Univariate and multivariate analyses showed that the tumor site, tumor size, mitotic index, tumor rupture, and prognostic nutritional index were significant factors associated with RFS. These variables were selected to create the nomogram for 2- and 5-year RFS (all P<0.05). The 2- and 5-year the ROC of the nomogram were 0.821 (95% confidence interval [CI]: 0.740–0.903) and 0.798 (95% CI: 0.739–0.903); NIH–Fletcher criteria were 0.757 (95% CI: 0.667–0.846) and 0.683 (95% CI: 0.613–0.753); NIH–Miettinen criteria were 0.762 (95% CI: 0.678–0.845) and 0.718 (95% CI: 0.653–0.783); Modified NIH criteria were 0.750 (95% CI: 0.661–0.838) and 0.689 (95% CI: 0.619–0.760); and AFIP were 0.777 (95% CI: 0.685–0.869) and 0.708 (95% CI: 0.636–0.780). Hence, the predictive probabilities of our nomogram are better than those of other GIST risk stratification systems.

Conclusion

This nomogram, combining tumor site, tumor size, mitotic index, tumor rupture, and prognostic nutritional index, may assist physicians in providing individualized treatment and surveillance protocols for patients with GISTs following surgical resection.

Single-cell transcriptome analysis revealed the heterogeneity and microenvironment of gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal tract. In this study, we performed single-cell RNA sequencing (RNA-seq) on intra- and peri-tumor tissues from GIST patients with the aim of discovering the heterogeneity of tumor cells in GIST and their interactions with other cells. We found four predominating cell types in GIST tumor tissue, including T cells, macrophages, tumor cells, and NK cells. Tumor cells could be clustered into two groups: one was highly proliferating and associated with high risk of metastasis, the other seemed "resting" and associated with low risk. Their clinical relevance and prognostic values were confirmed by RNA-seq of 65 GIST samples. T cells were the largest cell type in our single-cell data. Two groups of CD8⁺ effector memory (EM) cells were in the highest clonal expansion and performed the highest cytotoxicity but were also the most exhausted among all T cells. A group of macrophages were found polarized to possess both M1 and M2 signatures, and increased along with tumor progression. Cell-to-cell interaction analysis revealed that adipose endothelial cells had high interactions with tumor cells to facilitate their progression. Macrophages were at the center of the tumor microenvironment, recruiting immune cells to the tumor site and having most interactions with both tumor and nontumor cells. In conclusion, we obtained an overview of the GIST microenvironment and revealed the heterogeneity of each cell type and their relevance to risk classifications, which provided a novel theoretical basis for learning and curing GISTs.

Efficacy evaluation of nilotinib treatment in different genomic subtypes of gastrointestinal stromal tumors: A meta-analysis and systematic review

Nilotinib has been used as a third-line drug for gastrointestinal stromal tumors (GISTs) after a failure of sunitinib. In this study, we aimed to evaluate the efficacy of nilotinib in different genomic subtypes of GISTs. We searched the English articles through EMBASE, Cochrane Library and PubMed Database regarding to the use of nilotinib on GISTs, which published up to February 15, 2019. Inclusion criteria were: GISTs patients received nilotinib in a clinical trial and had detailed genetic subtype records (such as KIT exon 9, KIT exon 11, or PDGFRA mutations, or wild-type). The clinical benefit rate was used to assess the efficacy of nilotinib. A total of 3 studies involving 218 GISTs were included in this meta-analysis. The overall OR (KIT group vs WT group) was 3.26 (95% CI: 1.14-9.28; P = 0.027, P_{heterogeneity} = 0.613). The overall OR in KIT exon 11 group vs WT group was 5.30 (95% CI: 1.79-15.68; P = 0.003, P_{heterogeneity} = 0.409). The overall OR in KIT exon 9 group vs WT group was 0.13 (95% CI: 0.02-0.86; P = 0.035, P_{heterogeneity} = 0.229). The overall OR in KIT exon 11 group vs exon 9 group was 9.96 (95% CI: 0.39-254.66; P < 0.0001, P_{heterogeneity} = 0.024). Different genotypes of GISTs showed different responses to nilotinib, and KIT exon 11-mutant GISTs mostly benefited from nilotinib, followed by KIT exon 9-mutant or WT one.

Co-Incidence of Paraesophageal Hernia and Perforated Gastrointestinal Stromal Tumor: A Case Report on Rare Presentation of GIST

Introduction: The most common connective tissue neoplasm of the gastrointestinal tract is gastrointestinal stromal tumors (GISTs). Its presentations are usually abdominal pain and gastrointestinal bleeding. Case Presentation: We report a 31-year-old man with abdominal pain presented to our hospital with 10 days history of abdominal pain. After radiologic investigations, total distended stomach paraesophageal hernia and antral deformity were seen in the CT scan. Subsequently, the patient underwent surgery and after releasing the stomach, a large sealed perforated mass was seen in the antrum near the diaphragmatic hiatus and small localized abscess that subtotal gastrectomy and hernia repair was done. Pathologic examination revealed that the perforated mass is a GIST. Conclusions: We report a rare complication of gist that is perforation and the first report of simultaneous paraesophageal hernia and perforated gist.

Gastrointestinal Stromal Tumors (GISTs): Novel Therapeutic Strategies with Immunotherapy and Small Molecules

Gastrointestinal stromal tumors (GISTs) are the most common types of malignant mesenchymal tumors in the gastrointestinal tract, with an estimated incidence of 1.5/100.000 per year and 1–2% of gastrointestinal neoplasms. About 75–80% of patients have mutations in the KIT gene in exons 9, 11, 13, 14, 17, and 5–10% of patients have mutations in the platelet-derived growth factor receptor a (PDGFRA) gene in exons 12, 14, 18. Moreover, 10–15% of patients have no mutations and are classified as wild type GIST. The treatment for metastatic or unresectable GISTs includes imatinib, sunitinib, and regorafenib. So far, GIST therapies have raised great expectations and offered patients a better quality of life, but increased pharmacological resistance to tyrosine kinase inhibitors is often observed. New treatment options have emerged, with ripretinib, avapritinib, and cabozantinib getting approvals for these tumors. Nowadays, immune checkpoint inhibitors form a new landscape in cancer therapeutics and have already shown remarkable responses in various tumors. Studies in melanoma, non-small-cell lung cancer, and renal cell carcinoma are very encouraging as these inhibitors have increased survival rates. The purpose of this review is to present alternative approaches for the treatment of the GIST patients, such as combinations of immunotherapy and novel inhibitors with traditional therapies (tyrosine kinase inhibitors).

Controversies in EUS: Do we need miniprobes?

This is the fifth in a series of papers entitled "Controversies in EUS." In the current paper, we deal with high-resolution catheter probes, otherwise known as EUS miniprobes (EUS-MPs). The application of miniprobes for early carcinomas in the entire intestinal tract, for subepithelial lesions, and for findings in the bile duct and pancreatic duct as well as endobronchial use is critically discussed. Submucous lesions, especially in the colon, but also early carcinomas in special cases are considered the most important indications. The argument is illustrated by numerous examples.

Simultaneous Integrated Boost Intensity-Modulated Radiotherapy for Locally Advanced Drug-Resistant Gastrointestinal Stromal Tumors: A Feasibility Study

Background

As an emerging clinical problem, locally advanced drug-resistant gastrointestinal stromal tumors (LADRGISTs) has relatively few therapeutic schemes. Although radiotherapy is not often considered for GISTs, it could be a valuable contributing modality. The aim of our study is to explore a safe and effective radiation regimen for LADR-GISTs.

Methods

Three patients with LADR-GISTs were treated with simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) plans. In the SIB-IMRT plans, gross target volume (GTV) was divided into GTV-outer, GTV-mid, and GTV-center. And the prescribed dose of planning gross target volume (PGTV) and GTV-outer were both set to 50.4 Gy in 28 fractions. GTV-mid and GTV-center were simultaneously boosted to 60–62 Gy and 62–64 Gy respectively. For comparison purposes, conventional IMRT (Con-IMRT) plans with uniform dose distribution were generated for same optimization objectives without a dose boost to GTV-mid and GTV-center. All plans were optimized to make sure that deliver at least 95% of the prescription dose was delivered to PGTV. Isodose distribution, dose profiles, conformity indexes (CIs), monitor units (MUs), and dose volume histogram (DVH) was evaluated for each individual patient. After the three patients were treated with SIB-IMRT plans, the relative changes in the tumor size and CT values by CT scanning were also tracked.

Results

Compared with Con-IMRT plans, SIB-IMRT plans saw a significant increase from D₉₅ to D₂ of the GTV. With steeper dose gradients in the dose profiles, SIB-IMRT plans had GTV-mid and GTV-center accumulated with higher dose mainly by delivering extra 93 MUs in average. However, there was no significant difference in CIs and organs at risks (OARs) DVH. The relative changes in tumor size and CT values of the three patients in follow up were up to the Choi criteria and the three patients were all assessed as partial response.

Conclusions

The proposed SIB-IMRT may be a potential technique for achieving objective response and prolonging survival of selected GISTs patients.

Distinction of surgically resected gastrointestinal stromal tumor by near-infrared hyperspectral imaging

The diagnosis of gastrointestinal stromal tumor (GIST) using conventional endoscopy is difficult because submucosal tumor (SMT) lesions like GIST are covered by a mucosal layer. Near-infrared hyperspectral imaging (NIR-HSI) can obtain optical information from deep inside tissues. However, far less progress has been made in the development of techniques for distinguishing deep lesions like GIST. This study aimed to investigate whether NIR-HSI is suitable for distinguishing deep SMT lesions. In this study, 12 gastric GIST lesions were surgically resected and imaged with an NIR hyperspectral camera from the aspect of the mucosal surface. Thus, the images were obtained ex-vivo. The site of the GIST was defined by a pathologist using the NIR image to prepare training data for normal and GIST regions. A machine learning algorithm, support vector machine, was then used to predict normal and GIST regions. Results were displayed using color-coded regions. Although 7 specimens had a mucosal layer (thickness 0.4-2.5 mm) covering the GIST lesion, NIR-HSI analysis by machine learning showed normal and GIST regions as color-coded areas. The specificity, sensitivity, and accuracy of the results were 73.0%, 91.3%, and 86.1%, respectively. The study suggests that NIR-HSI analysis may potentially help distinguish deep lesions.

Lentivirus-Mediated Overexpression of SIVA-1 Reverses Cisplatin Resistance in Gastric Cancer in vitro

SIVA-1 plays a critical role in the induction of apoptosis in a number of different cell lines and participates in the mechanism of cisplatin (DDP)-mediated antitumor effects. However, the involvement of SIVA-1 in cisplatin resistance in gastric carcinoma has not been revealed. To explore the effect of SIVA-1 on DDP resistance, a recombinant pGV358-GFP-SIVA-1 lentiviral vector was constructed and transfected into human cisplatin-resistant MKN45/DDP gastric cancer cells. Subsequently, stable SIVA-1 overexpression was established in MKN45/DDP cells, which resulted in increased DDP sensitivity in MKN45/DDP cells in vitro. Flow cytometry demonstrated that SIVA-1 overexpression increased the percentage of apoptotic cells compared to that in the control. The colony formation assay clearly revealed that cell growth and proliferation were significantly suppressed following SIVA-1 overexpression. In addition, overexpression of SIVA-1 inhibited the migratory and invasive potential of MKN45/DDP cells in vitro. Western blot analysis indicated that SIVA-1 increased the expression levels of p53, p73, and p14ARF, whereas it reduced Bcl-2, MDM2, and Bcl-xL expression. In short, SIVA-1 upregulated the protein expression of p53, p73, and p14ARF and decreased that of Bcl-2, MDM2, and Bcl-xL in vitro and subsequently reversed cisplatin resistance in gastric cancer cells, suggesting that SIVA-1 serves as a valuable potential target for attenuating chemotherapy resistance.

Efficacy of endoscopic ultrasound with artificial intelligence for the diagnosis of gastrointestinal stromal tumors

BACKGROUND

Although endoscopic ultrasound (EUS) is reported to be suitable for determining the layer from which subepithelial lesions (SELs) originate, it is difficult to distinguish gastrointestinal stromal tumor (GIST) from non-GIST using only EUS images. If artificial intelligence (AI) can be used for the diagnosis of SELs, it should provide several benefits, including objectivity, simplicity, and quickness. In this pilot study, we propose an AI diagnostic system for SELs and evaluate its efficacy.

METHODS

Thirty sets each of EUS images with SELs ≥ 20 mm or < 20 mm were prepared for diagnosis by an EUS diagnostic system with AI (EUS-AI) and three EUS experts. The EUS-AI and EUS experts diagnosed the SELs using solely the EUS images. The concordance rates of the EUS-AI and EUS experts' diagnoses were compared with the pathological findings of the SELs.

RESULTS

The accuracy, sensitivity, and specificity for SELs < 20 mm were 86.3, 86.3, and 62.5%, respectively for the EUS-AI, and 73.3, 68.2, and 87.5%, respectively, for the EUS experts. In contrast, accuracy, sensitivity, and specificity for SELs ≥ 20 mm were 90.0, 91.7, and 83.3%, respectively, for the EUS-AI, and 53.3, 50.0, and 83.3%, respectively, for the EUS experts. The area under the curve for the diagnostic yield of the EUS-AI for SELs ≥ 20 mm (0.965) was significantly higher than that (0.684) of the EUS experts (P = 0.007).

CONCLUSION

EUS-AI had a good diagnostic yield for SELs ≥ 20 mm. EUS-AI has potential as a good option for the diagnosis of SELs.

The Health-Related Quality of Life of Sarcoma Patients and Survivors in Germany-Cross-Sectional Results of a Nationwide Observational Study (PROSa)

Simple Summary

Sarcomas are a rare cancer with many different subtypes. They can occur anywhere in the body and are treated in a multi-disciplinary manner. Large studies on the quality of life of sarcoma patients are rare, so little is known about how patients are doing compared to the general population and which groups of sarcoma patients are particularly affected by quality of life limitations. We assessed the quality of life of 1113 sarcoma patients from Germany. The majority were particularly restricted in their emotional functioning, physical functioning, and the exercise of everyday demands (role function). Many of them experienced pain (56%) and fatigue (51%). We found that patients with leg or bone sarcomas were especially affected by quality of life limitations. We also found that patients who received a retirement pension were less affected by quality of life restrictions than patients who had not retired.

Abstract

Sarcomas are rare cancers with high heterogeneity in terms of type, location, and treatment. The health-related quality of life (HRQoL) of sarcoma patients has rarely been investigated and is the subject of this analysis. Adult sarcoma patients and survivors were assessed between September 2017 and February 2019 in 39 study centers in Germany using standardized, validated questionnaires (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30)). Associated factors were analyzed exploratively using multivariable linear regressions. Among 1113 patients, clinically important limitations and symptoms were most pronounced in emotional (63%, 95% CI 60–66%), physical (60%, 95% CI 57–62%), role functioning (51%, 95% CI 48–54%), and pain (56%, 95% CI 53–59%) and fatigue (51%, 95% CI 48–54%). HRQoL differed between tumor locations with lower extremities performing the worst and sarcoma types with bone sarcoma types being most affected. Additionally, female gender, higher age, lower socioeconomic status, recurrent disease, not being in retirement, comorbidities, and being in treatment were associated with lower HRQoL. Sarcoma patients are severely restricted in their HRQoL, especially in functioning scales. The heterogeneity of sarcomas with regard to type and location is reflected in HRQoL outcomes. During treatment and follow-up, close attention has to be paid to the reintegration of the patients into daily life as well as to their physical abilities and emotional distress.

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

INTRODUCTION

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

PRESENTATION OF CASE

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

DISCUSSION

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

CONCLUSION

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

Utility of Circulating Tumor DNA in the Management of Patients With GI Stromal Tumor: Analysis of 243 Patients

PURPOSE

GI stromal tumor (GIST) is the most common sarcoma of the GI tract. Management of patients with GIST is determined by KIT, PDGFRA, or other genomic alterations. Tissue-based next-generation sequencing (NGS) analysis is the standard approach for diagnosis, prognosis, and treatment selection. However, circulating tumor DNA (ctDNA)–based NGS is a novel and noninvasive alternative.

METHODS

ctDNA sequencing results were evaluated in blood samples from 243 de-identified patients within the Guardant360 database. Under an approved institutional review board protocol, a retrospective analysis was performed on 45 single-institution patients.

RESULTS

Of 243 patients, 114 (47%) were women, and the median age was 59 years (range, 17-90 years). Patients with no alterations and variations of uncertain significance were excluded. Of the 162 patients with known pathogenic mutations, KIT was the most common (56%), followed by NF (7%), PDGFRA (6%), PI3KCA (6%), KRAS (5%), and others (6%). Most tumors harbored an actionable KIT or PDGFRA mutation. Our institutional cohort (n = 45) had 16 (35%) KIT exon 11 mutations, 3 (6%) KIT exon 9 mutations, and 1 (2%) PDGFRA mutation detected on ctDNA. Resistance mutations were observed in KIT exon 17 (8 patients), exon 13 (3 patients), and in both (3 patients). Our comparison of ctDNA with tissue NGS revealed a positive predictive value (PPV) of 100%. Failure of concordance was observed in patients with localized or low disease burden. From the time of ctDNA testing, the median overall survival was not reached, whereas the median progression-free survival was 7 months.

CONCLUSION

ctDNA provides a rapid, noninvasive analysis of current mutations with a high PPV for patients with metastatic GIST. ctDNA-based testing may help to define the optimal choice of therapy on the basis of resistance mutations and should be studied prospectively.

Gastrointestinal Stromal Tumors Incidentalomas: A Case Series

BACKGROUND

Gastrointestinal stromal tumors (GISTs) represent approximately 0.2% of all gastrointestinal tumors. GISTs can occur anywhere along the length of the gastrointestinal tract. Most common clinical manifestations of GISTs include GI bleeding, abdominal discomfort, distention and pain. Small lesions can be found incidentally during imaging studies, endoscopy, surgery and post-mortem. The progression of disease from incidentally found indolent to symptomatic disease is unknown.

CASE SERIES

Here we describe a series of cases of incidentally found GIST and their management. The first patient was a 38-years old morbid obese female with an incidentally found GIST in the stomach following an elective laparoscopic vertical sleeve gastrectomy. The second patient was a 69-year-old male who underwent elective sleeve gastrectomy for his obesity and associated refractory acid reflux. On pathologic examination of the gastrectomy specimen, GIST was diagnosed in the gastric fundus.

DISCUSSION

Coexistence of GIST with other malignancies is higher than previously reported and should draw attention of clinicians towards these incidental findings. Prognosis in these patients is usually determined by other malignancy and not significantly influenced by GIST. Therefore, treatment algorithms should be focused on prognostically relevant malignancy.

Comparison of endoscopic versus laparoscopic resection for gastric gastrointestinal stromal tumors: A preliminary meta-analysis

BACKGROUND AND AIM

For localized disease, complete surgical resection is regarded as the "gold standard" therapeutic modality. With the rapid development of endoscopic techniques, endoscopic resection (ESR) has been confirmed as an efficient and safe alternative for the treatment of gastrointestinal stromal tumors (GISTs) in the stomach. Nevertheless, the management of gastric GISTs remains poorly defined. The purpose of this study is to evaluate the security and effectiveness of ESR with laparoscopic resection (LAR) for gastric GISTs.

METHODS

A literature search of online databases was conducted to identify relevant comparative studies of ESR and LAR procedures for gastric GISTs published before April 10, 2020. The cumulative data analysis was also performed utilizing the software STATA.

RESULTS

In total, 10 studies involving 1165 patients met the inclusion criteria for analysis (651 for ESR and 514 for LAR). From the results of meta-analysis, patients who underwent ESR experienced decreased operative time (P = 0.000), less intraoperative blood loss (P = 0.002), earlier time to diet (P = 0.000), shorter hospital stay (P = 0.000), and lower total charges (P = 0.000) compared with LAR. Moreover, there were no significant differences between these two approaches concerning tumor rupture, conversion rate to other procedure, complete resection rate, postoperative complication rate, recurrence rate, and disease-free survival.

CONCLUSIONS

Endoscopic resection, as an effective alternative treatment strategy with satisfactory outcomes, is acceptable for selective patients with gastric GISTs compared with LAR. Further well-designed randomized controlled trials with large samples are warranted to corroborate our observations.

Gastrointestinal Stromal Tumor – An Overview

Gastrointestinal stromal tumors (GISTs) are rare tumors but are most common mesenchymal tumors of the digestive tract. They are commonly seen in the stomach (60%) and small intestine (30%). GISTs are likely derived from the interstitial cells of Cajal or their stem cell precursors. They are best characterized by computerized tomography and have a specific staining pattern on immunohistochemistry, i.e., C-Kit and DOG-1. The treatment of GIST is based on the risk assessment for relapse, and patients with localized GIST require resection with or without adjuvant imatinib mesylate (IM). Advanced unresectable tumors are usually treated with IM, with a number of further options available for patients post progression on IM. There is an increasing emphasis on identifying C-Kit and platelet-derived growth factor receptor alpha mutations in all patients with GIST, as these are driver mutations with current and future therapeutic implications.

A multi-class scoring system based on CT features for preoperative prediction in gastric gastrointestinal stromal tumors

Our study aimed to establish and validate a multi-class scoring system for preoperative gastric gastrointestinal stromal tumors (GISTs) risk stratifications based on CT features. 150 gastric GIST patients who underwent contrast-enhanced CT examination and surgical resection from hospital 1 were retrospectively analyzed as the training cohort, and 61 patients from hospitals 2 and 3 were included as the validation cohort. A model was established by logistic regression analysis and weighted to be a scoring model. A calibration test, area under the receiver operating characteristic (ROC) curve (AUC), and cutoff points were determined for the score model. The model was also divided into three score ranges for convenient clinical evaluation. Five CT features were included in the score model, including tumor size (4 points), ill-defined margin (6 points), intratumoral enlarged vessels (5 points), heterogeneous enhancement pattern (4 points), and exophytic or mixed growth pattern (2 points). Then, based on the calibration results, performance was merely assessed as very low and high* risk. The AUCs of the score model for very low risk and high* risk were 0.973 and 0.977, and the cutoff points were 3 points (97.30%, 93.81%) and 7 points (92.19%, 94.19%), respectively. In the validation cohort, the AUCs were 0.912 and 0.972, and the cutoff values were 3 points (92.31%, 85.42%) and 5 points (100%, 87.88%), respectively. The model was stratified into 3 ranges: 0-3 points for very low risk, 4-8 points for low risk, and 9-21 points for high* risk. A concise and practical score system for gastric GISTs risk stratification was proposed.

Preoperative CT feature of incomplete overlying enhancing mucosa as a high-risk predictor in gastrointestinal stromal tumors of the stomach

OBJECTIVES

To determine whether the CT finding of overlying enhancing gastric mucosa (OEGM) can be used to predict risk stratifications by observing CT features of gastrointestinal stromal tumors (GISTs) of the stomach.

METHODS

Clinical characteristics and CT features within pathologically demonstrated GISTs were retrospectively reviewed. Risk stratifications were classified into non-high group and high-risk group according to the modified National Institutes of Health criteria. Univariate analysis and multivariate logistic regression analysis were performed in order to determine significant predictors for high-risk stratification. Receiver operating characteristic (ROC) curve analysis, subgroup analysis, and pathologic-radiologic correlation analysis were all executed.

RESULTS

A total of 147 patients were finally enrolled as test subjects. Within the univariate analysis, high-risk tumors tended to have a larger diameter, irregular shape, exophytic growth pattern, present necrosis, incomplete OEGM, tumor vessels, heterogeneous enhancement, and present rupture. According to ROC curve analysis, incomplete OEGM showed the largest area under curve values for diagnosing lesions (0.835; 95% CI, 0.766-0.904; p < 0.001). Multivariate analysis showed that the incomplete OEGM was the strongest independent predictor for high-risk stratification of gastric GISTs (OR = 21.944; 95% CI, 4.344-110.863; p < 0.001). Within the subgroup analysis, incomplete OEGM was more frequently associated with tumors size > 10 cm, irregular shape, exophytic growth pattern, high mitotic count, and disrupted mucosa on pathology.

CONCLUSIONS

The CT feature of incomplete OEGM is an independent predictive factor for high-risk stratification of gastric GISTs and strongly correlated with pathological mucosal changes.

KEY POINTS

• Preoperative CT features can be helpful in assessment of risk stratifications of gastric GISTs. • OEGM is an independent predictor for high-risk stratification of gastric GISTs. • Incomplete OEGM likely indicates high-risk stratification of gastric GISTs.

Massive bleeding of a jejunal gastrointestinal stromal tumour: a rare case of a life-threatening presentation

A jejunal gastrointestinal stromal tumour (GIST) is a rare neoplasm of the gastrointestinal tract. Massive bleeding due to a jejunal GIST is a diagnostic challenge and could present as a life-threatening situation needing urgent intervention. A 54-year-old woman presented with episodes of melaena and haematochezia for the previous 3 days. An oesophagoduodenoscopy was inconclusive. A contrast computed tomography (CT) scan showed a well-defined extraluminal mass in the proximal jejunum suggestive of a bleeding GIST. Her haemodynamic state deteriorated despite initial supportive therapy including a blood transfusion. An urgent laparotomy to excise the jejunal mass was performed. Histopathology and immunohistochemical studies confirmed the diagnosis. She subsequently received adjuvant imatinib therapy. She has remained symptom free at 5 months post-op. We therefore present a rare case of obscure massive gastrointestinal bleeding due to a jejunal GIST. The CT scan was the most effective investigation to detect the source of bleeding in this case.

MRI Texture-Based Models for Predicting Mitotic Index and Risk Classification of Gastrointestinal Stromal Tumors

BACKGROUND

Treatment regimens and prognoses of gastrointestinal stromal tumors (GIST) are quite different for tumors in different risk categories. Accurate preoperative grading of tumors is important for avoiding under- or overtreatment.

PURPOSE

To develop and validate an MRI texture-based model to predict the mitotic index and its risk classification.

STUDY TYPE

Retrospective.

POPULATION

Ninety-one patients with histologically-confirmed GIST; 64 patients in a training cohort, and 27 patients in a test cohort.

FIELD STRENGTH/SEQUENCE

T₂ -weighted imaging (T₂ WI), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) at 1.5T.

ASSESSMENT

GIST images were manually segmented by two independent radiologists using ITK-SNAP software and MRI features were extracted using Pyradiomics. Two pathologists reviewed the tissue specimens of the tumors to identify the mitotic index and risk classification in consensus.

STATISTICAL TESTS

The least absolute shrinkage and selection operator (LASSO) regression method was used to select texture features. A logistic regression model was established based on the radiomic score (radscore), tumor location, and maximum diameter to predict tumor classification and develop a nomogram. Receiver operator characteristic (ROC) curves were used to evaluate the ability of the nomogram to distinguish between two tumors with different risk classifications, and a calibration curve was used to evaluate the consistency between the predicted risk and the actual risk.

RESULTS

The texture signature achieved high efficacy in predicting the mitotic index area under the curve ([AUC], 0.906; 95% confidence interval [CI]: 0.813, 0.961). A nomogram for prediction of the risk classification of GIST, which incorporated this texture signature together with maximum tumor diameter and location, allowed good discrimination in the training cohort (AUC, 0.878; 95% CI: 0.769, 0.960) and the validation cohort (AUC, 0.903; 95% CI: 0.732, 0.922).

DATA CONCLUSION

The texture-based model can be used to predict GIST mitotic index and risk classification preoperatively.

LEVEL OF EVIDENCE

2.

TECHNICAL EFFICACY STAGE

3.

Evaluation of Upper Endoscopic and Endoscopic Ultrasound Features in the Differential Diagnosis of Gastrointestinal Stromal Tumors and Leiomyomas in the Upper Gastrointestinal Tract

Background

Differentiation between benign and malignant subepithelial lesions (SELs) in the upper gastrointestinal tract (UGT) leads to far-reaching clinical consequences. An accurate diagnosis can be challenging because of the insufficient diagnostic yield of upper endoscopy, endoscopic ultrasound (EUS), and different types of biopsy.

Aim

Our aim was to reveal the efficacy of upper endoscopic and EUS features for the differential diagnosis of hypoechogenic SELs (gastrointestinal stromal tumors [GISTs] and leiomyomas) in the UGT.

Materials and Methods

The research covers a case series study of 27 hypoechogenic SELs in the UGT between 2012 and 2015 at Vilnius University Hospital Santaros Klinikos. Upper endoscopic and EUS features of SELs were recorded. In order to standardize the diagnostic approach to GISTs and leiomyomas, we assigned scores for seven upper endoscopic and EUS features.

Results

The mean total scores in the GIST group were significantly higher than those in the leiomyoma group: 3.25 ± 1.71 and 0.53 ± 0.83 (p < 0.0001), respectively. Increment by one score increased the odds ratio for GIST 5.87 times (95% CI 1.63-21.11; p = 0.007). The total score demonstrated very good discriminatory features of GISTs against leiomyomas (area under the receiver operating characteristic curve 0.94 [0.86-1]). The cutoff value of 1.5 total score indicated 83.3% sensitivity and 93.3% specificity in diagnosing GISTs.

Conclusions

Upper endoscopy and EUS are useful methods in making a definite diagnosis of SELs. Their diagnostic accuracy for the differential diagnosis of GISTs and leiomyomas is sufficient.

Application of A Convolutional Neural Network in The Diagnosis of Gastric Mesenchymal Tumors on Endoscopic Ultrasonography Images

Background and Aims: Endoscopic ultrasonography (EUS) is a useful diagnostic modality for evaluating gastric mesenchymal tumors; however, differentiating gastrointestinal stromal tumors (GISTs) from benign mesenchymal tumors such as leiomyomas and schwannomas remains challenging. For this reason, we developed a convolutional neural network computer-aided diagnosis (CNN-CAD) system that can analyze gastric mesenchymal tumors on EUS images. Methods: A total of 905 EUS images of gastric mesenchymal tumors (pathologically confirmed GIST, leiomyoma, and schwannoma) were used as a training dataset. Validation was performed using 212 EUS images of gastric mesenchymal tumors. This test dataset was interpreted by three experienced and three junior endoscopists. Results: The sensitivity, specificity, and accuracy of the CNN-CAD system for differentiating GISTs from non-GIST tumors were 83.0%, 75.5%, and 79.2%, respectively. Its diagnostic specificity and accuracy were significantly higher than those of two experienced and one junior endoscopists. In the further sequential analysis to differentiate leiomyoma from schwannoma in non-GIST tumors, the final diagnostic accuracy of the CNN-CAD system was 75.5%, which was significantly higher than that of two experienced and one junior endoscopists. Conclusions: Our CNN-CAD system showed high accuracy in diagnosing gastric mesenchymal tumors on EUS images. It may complement the current clinical practices in the EUS diagnosis of gastric mesenchymal tumors.

Usefulness of tumor traction with a snare and endoclips in gastric submucosal tumor resection: a propensity-score-matching analysis

Background

Endoscopic resection, including endoscopic submucosal dissection (ESD) and endoscopic full-thickness resection (EFR), was used to resect small gastric submucosal tumors (SMTs). Our team explored a method of tumor traction using a snare combined with endoclips to assist in the resection of SMTs. This study aims to explore the safety and effectiveness of the method.

Methods

This research performed a propensity-score-matching (PSM) analysis to compare ESD/EFR assisted by a snare combined with endoclips (ESD/EFR with snare traction) with conventional ESD/EFR for the resection of gastric SMTs. Comparisons were made between the two groups, including operative time, en bloc resection rate, perioperative complications, and operation-related costs.

Results

A total of 253 patients with gastric SMTs resected between January 2012 and March 2019 were included in this study. PSM yielded 51 matched pairs. No significant differences were identified between the two groups in perioperative complications or the costs of disposable endoscopic surgical accessories. However, the ESD/EFR-with-snare-traction group had a shorter median operative time (39 vs 60 min, P = 0.005) and lower rate of en bloc resection (88.2% vs 100%, P = 0.027).

Conclusions

ESD/EFR with snare traction demonstrated a higher efficiency and en bloc resection rate for gastric SMTs, with no increases in perioperative complications and the costs of endoscopic surgical accessories. Therefore, the method seems an appropriate choice for the resection of gastric SMTs.

The prognostic value of gender in gastric gastrointestinal stromal tumors: a propensity score matching analysis

Background

Gastrointestinal stromal tumors (GISTs) of the stomach are the most common GISTs. The risk, incidence, and outcome of cancer are different between the sexes. Whether gender is related to the prognosis of gastric stromal tumors is unclear. Therefore, this study aims to explore the relationship between gender and gastric GIST prognosis.

Methods

Data from gastric GIST patients were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was performed to reduce confounding factors, and the clinicopathological features and prognosis of GIST patients were comprehensively evaluated.

Results

There were 512 male patients and 538 female patients with gastric GIST. The gender of gastric GIST patients was associated with marital status, surgical treatment, tumor size, and mitotic index (P < 0.05). The Kaplan-Meier analysis and log-rank test revealed that male patients had a higher mortality rate than female patients (P = 0.0024). After matching all the potential confounding factors, the survival of the female gastric GIST patients was better than that of the male gastric GIST patients (P = 0.042). Cox regression analysis revealed that gender was an independent risk factor for overall survival. The risk of death was higher for males than for females (HR 1.677, 95% CI 1.150–2.444, P = 0.007).

Conclusion

Gender could be a prognostic factor for gastric GIST survival, and male patients had a higher risk of death.

Spontaneous perforation of jejunal gastrointestinal stromal tumor: A case report

•

GIST is rare and its presentation as spontaneous rupture is extremely rare.

•

GIST preoperative diagnosis remains difficult.

•

Local excision of the GIST associated with the use of imatinib is effective.

•

GIST is a rare pathological condition.

Introduction

The incidence of small bowel tumors is comparatively rare when compared to colonic tumors. They comprise less than 10% of all gastrointestinal neoplasms. Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract; however it accounts for less than 1% of all gastrointestinal tumors.

Aim

To report a rare case of jejunal gastrointestinal stromal tumor presenting as a life-threatening emergency in a young adult male who was treated in the General Surgery department in the Jordanian Royal Medical Services (JRMS), Amman, Jordan. PRESENTED CASE: We report a 59-year-old male who presented to our emergency department with severe generalized abdominal pain. The patient was in a hypovolemic shock. Abdominal examination revealed a massively distended, tender abdomen. Abdomenal CT scan with IV contrast showed significant fat stranding around the jejunum associated with pneumoperitoneum and free fluid. Exploratory laparotomy was emergently performed, revealing diffuse peritonitis secondary to perforated small bowel tumor. En bloc resection was performed. Histopathologic examination confirmed the presence of malignant gastrointestinal stromal tumor of the jejunum with R0 clearance.

Discussion

Gastrointestinal stromal tumors are relatively rare and the jejunum is the least affected among other parts of the GI tract. The majority of ruptured GISTs occur spontaneously, and are located in the stomach and small bowel. Most ruptured GISTs are associated with dismal prognosis.

Conclusion

A jejunal gastrointestinal stromal tumor can rarely present with spontaneous perforation. However, it is important to highlight this condition, as early emergency intervention constitutes the key to a good outcome.

Advanced pharmacological therapies for neurofibromatosis type 1-related tumors

Neurofibromatosis Type 1 (NF1) is an autosomal dominant tumor-predisposition disorder that is caused by a heterozygous loss of function variant in the NF1 gene, which encodes a protein called neurofibromin. The absence of neurofibromin causes increased activity in the Rat sarcoma protein (RAS) signalling pathway, which results in an increased growth and cell proliferation. As a result, both oncological and non-oncological comorbidities contribute to a high morbidity and mortality in these patients. Optic pathways gliomas, plexiform neurofibromas and malignant peripheral nerve sheath tumor (MPNST) are the most frequent NF1-associated tumors. The treatment of these complications is often challenging, since surgery may not be feasible due to the location, size, and infiltrative nature of these tumors, and standard chemotherapy or radiotherapy are burdened by significant toxicity and risk for secondary malignancies. For these reasons, following the novel discoveries of the pathophysiological mechanisms that lead to cell proliferation and tumorigenesis in NF1 patients, emerging drugs targeting specific signalling pathways (i.e. the MEK/ERK cascade), have been developed with promising results.

Endoscopic Submucosal Dissection of Gastrointestinal Stromal Tumours: A Retrospective Cohort Study

Background

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal neoplasms. Endoscopic submucosal dissection (ESD) has been used to remove submucosal tumours for many years. However, whether ESD can be recommended for the treatment of GISTs is still controversial. Therefore, we evaluated the efficacy and safety of ESD for treating GISTs.

Patients and Methods

We retrospectively analysed 75 GIST patients who underwent ESD in our hospital from January 2016 to December 2018, and the demographic data, clinical presentation of tumours, operative parameters, postoperative complications and length of hospital stay were analysed.

Results

Seventy-five patients successfully underwent en bloc resection, and 74 (98.7%) patients underwent complete resection of the lesions, with an average tumour size of 1.7 cm (range 0.3–6.0 cm). The median operation time was 84.8 min (range 20–180 min). Forty-two (56.0%) patients underwent endoscopic purse-string suture with no conversions to an open operation. The median postoperative length of hospitalization was 6.6 days (range 3–14 days). Out of a total of 75 GIST patients, 48 (64.0%) were considered very low risk, 19 (25.3%) were low risk, 5 (6.7%) were mild risk, and 3 (4.0%) were high risk. The median follow-up was 24.0 months (range 6–45 months). During hospitalization and follow-up, no complications, recurrence or metastasis occurred.

Conclusion

Based on our study from a medical centre, ESD is a safe and effective method for treating GISTs. However, further studies are needed.

Immune-infiltration based signature as a novel prognostic biomarker in gastrointestinal stromal tumour

BACKGROUND

Accumulating evidence indicates that tumour-infiltrating lymphocytes (TILs) are the primary determinant of survival outcomes in various tumours. Thus, we sought to investigate the TIL distribution and density in gastrointestinal stromal tumours (GISTs) and to develop an immune infiltration (II)-based signature to predict prognosis.

METHODS

The expression of 8 immune features in the tumour centre (TC) and tumour margin (TM) and PD-L1 in 435 GIST patients was investigated by immunohistochemistry. Then, a 4-feature-based II-GIST signature integrating the CD3⁺ TC, CD3⁺ TM, CD8⁺ TM and CD45RO⁺ TM parameters was developed using a LASSO Cox regression model in the training cohort and was validated in two separate validation cohorts.

FINDINGS

High CD3⁺ TC, CD3⁺ TM, CD8⁺ TC, CD8⁺ TM, CD45RO⁺ TM, NKp46⁺ TM and CD20⁺ TM correlated with improved survival. Patients with high II-GIST scores have better RFS and OS outcomes than those with low II-GIST scores. Multivariable analyses demonstrated that the II-GIST signature is an independent prognostic factor. The receiver operating characteristic (ROC) curve demonstrated that the prognostic accuracy of the II-GIST signature is superior to that of the NIH risk criteria. Further analysis showed that moderate- and high-risk GIST patients with high II-GIST scores could gain survival benefits from adjuvant imatinib therapy.

INTERPRETATION

The novel II-GIST signature accurately predicted the survival outcomes of GIST patients. In addition, the II-GIST signature was a useful predictor of survival benefit from imatinib therapy amongst moderate- and high-risk patients with GIST.

FUNDING

This project was supported by National Natural Science Foundation of China (81702325), Natural Science Foundation of Guangdong Province (2017A030310565), and 3&3 Project of the First Affiliated Hospital of Sun Yat-sen University.

A Serosa-Originated Gastric Stromal Tumor Misdiagnosed by Ultrasonography and Frozen Section Pathology: A Case Report

Gastric gastrointestinal stromal tumor (GIST) is a mesenchymal neoplasm, typically arising from the muscularis propria layer of the stomach wall. Serosa-derived GIST is rarely seen and has not been reported yet. A 49-year-old Chinese female was presented with marked abdominal distension. Ultrasonography revealed a retroperitoneal tumor adjacent to the stomach wall with an intact structure of five echo layers, indicating a non-stomach tumor origin. Preoperative radiological studies suggested tight tumor-stomach adjacency, which was confirmed by intraoperative dissection. Initial frozen section indicated a pathological diagnosis of spindle cell tumor, which turned out to be a gastric GIST originated from the serosa layer of the stomach wall. The current case demonstrates the rare occurrence of serosa-derived GIST. This case also suggests difficulties in preoperative diagnosis of gastric GISTs, especially when uncommon pathological conditions like rare tumor origins were presented.

Diagnosing Gastric Mesenchymal Tumors by Digital Endoscopic Ultrasonography Image Analysis

Gastric mesenchymal tumors (GMTs) are incidentally discovered in national gastric screening programs in Korea. Endoscopic ultrasonography (EUS) is the most useful diagnostic modality for evaluating GMTs. The differentiation of gastrointestinal stromal tumors from benign mesenchymal tumors, such as schwannomas or leiomyomas, is important to ensure appropriate clinical management. However, this is difficult and operator dependent because of the subjective interpretation of EUS images. Digital image analysis computes the distribution and spatial variation of pixels using texture analysis to extract useful data, enabling the objective analysis of EUS images and decreasing interobserver and intraobserver agreement in EUS image interpretation. This review aimed to summarize the usefulness and future of digital EUS image analysis for GMTs based on published reports and our experience.

Wireless Power Transfer for Implanted Medical Application: A Review

With ever-increasing concerns on health and environmental safety, there is a fast-growing interest in new technologies for medical devices and applications. Particularly, wireless power transfer (WPT) technology provides reliable and convenient power charging for implant medical devices without additional surgery. For those WPT medical systems, the width of the human body restricts the charging distance, while the specific absorption rate (SAR) standard limits the intensity of the electromagnetic field. In order to develop a high-efficient charging strategy for medical implants, the key factors of transmission distance, coil structure, resonant frequency, etc. are paid special attention. In this paper, a comprehensive overview of near-field WPT technologies in medical devices is presented and discussed. Also, future development is discussed for the prediction of different devices when embedded in various locations of the human body. Moreover, the key issues including power transfer efficiency and output power are addressed and analyzed. All concerning characteristics of WPT links for medical usage are elaborated and discussed. Thus, this review provides an in-depth investigation and the whole map for WPT technologies applied in medical applications.

Gastrointestinal Stromal Tumors of the Small Intestine: Progress in Diagnosis and Treatment Research

In recent years, the diagnosis and treatment of gastrointestinal stromal tumors (GISTs) of the small intestine have been a hot topic due to their rarity and non-specific clinical manifestations. With the development of gene and imaging technology, surgery, and molecular targeted drugs, the diagnosis and treatment of GISTs have achieved great success. For a long time, radical resection was prioritized to treat GISTs of the small intestine. At present, preoperative tumor staging is a novel treatment for unresectable malignant tumors. In addition, karyokinesis exponent is the sole independent predictor of progression-free survival of GISTs. The DNA, miRNA, and protein of exosomes have also been found to be biomarkers with prognostic implications. The research on the treatment of GISTs has become a focus in the era of precision medicine, ushering in the use of standardized, normalized, and individualized treatment.

Clinicopathologic and Surgical Characteristics Study of 151 Cases of GIST

BACKGROUND

Gastrointestinal stromal tumor (GIST) is the most appearing mesenchymal tumor of the gastrointestinal system. In this study, we are aiming to share the most up to date knowledge about diagnosis and treatment of these tumors by transferring our clinical experience about GISTs.

METHODS

The 151 patients who were operated between 2006-2020 and whose pathological examination was reported as GIST were analyzed retrospectively. Demographic, clinical, and pathological features and treatment methods of patients were evaluated.

RESULTS

Seeventy-six of the patients were women and 75 of them were men whose age averages were 66.1 (31-86). The most common location was the stomach (55.6%), followed by the small intestine, retroperitoneal, large intestine, rectum, esophagus, and another organ. With surgical intervention, 139 of them had been cured. Twelve of cases were accepted as inoperable. The diameter of tumors in our cases were between 0.4 cm and 35 cm. Determined mitotic activity was ≤ 5 in 71 patients and 5 < in 80 patients. In 8 of 12 unresectable cases, it has been seen that partial remission after the treatment of 12-month tyrosine kinase inhibitors, C-KIT, was positive in 96.7% of our cases. CD34 and Ki-67 was analyzed in patients. CD34 was found positive in 98 (64.9%) of them, Ki-67 was positive in 82 (54.3%) patients. Patients had been observed for 40 months.

CONCLUSION

Despite GISTs are not appearing frequently, nowadays they have started to be seen more frequently than before with the growing present-day diagnostic methods. The ideal treatment is performing radical resection without leaving any tumor cells behind. Tyrosine kinase inhibitors have an important place in unresectable cases.

Drug Development in Soft Tissue Sarcomas: Novel Targets and Recent Early Phase Trial Results

Soft tissue sarcomas are a heterogeneous group of rare malignancies with few effective standard therapies. Our understanding of the underlying biology driving tumorigenesis in these mesenchymal tumors have led to a growth in drug development for soft tissue sarcomas. This review focuses on novel targets in soft tissue sarcomas, describes early clinical trial results of drugs directed at these targets, and discusses the data surrounding the use of these compounds in clinical practice and rationale for possible future US Food and Drug Administration approvals.

Signet Ring Cell Carcinoma Mimicking Gastric Gastrointestinal Stromal Tumor: A Case Report

The presentation of submucosal gastric cancer, especially signet ring cell carcinoma, is rare. The submucosal tumor (SMT) is covered with normal mucosa, and confirmation is difficult through endoscopic biopsy; thus, histologic diagnosis is important to determine the appropriate treatment method. Here, we report a case of gastric signet ring cell carcinoma mimicking gastrointestinal stromal tumor (GIST). A 2-cm-sized SMT suspected of being a GIST on preoperative endoscopic ultrasonography and computed tomography was suspected to be cancerous during surgery. The frozen diagnosis of the resected mass (obtained via wedge resection) showed a carcinoma with signet ring feature, and additional frozen diagnosis of one enlarged lymph node revealed metastatic cancer. Therefore, subtotal gastrectomy with lymph node dissection was performed. This case report suggests that preoperative histologic diagnosis of high-risk SMT might be useful, although the tumor had typical features of GIST on preoperative imaging. Overall, if a tumor is suspected of being a gastric carcinoma during surgery and the differential diagnosis between gastric carcinoma and GIST is uncertain, a careful surgical approach should be considered to account for the possibility of adenocarcinoma.

Treatment of a Gastrointestinal Stromal Tumor (GIST) Adherent to the Spleen and the Tail of the Pancreas: A Case Report

BACKGROUND Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal gastrointestinal tumors (GIT). Usually, they appear in patients ages 55-65 years, with no apparent difference between males and females. Their annual incidence is about 11-14 per 10⁶. They generally do not present with any prominent symptoms, appearing with the atypical symptoms of abdominal pain, weight loss, early satiety, and occasionally bleeding. Adequate surgical treatment involves sphenoid resection of the tumor within clear margins. If adjacent organs are involved, en bloc resection is the procedure of choice. CASE REPORT A 62-year-old male patient presented to the Emergency Department complaining of melena for 1 week. He underwent gastroscopy, colonoscopy and abdominal computed tomography scan, which revealed a large, exophytic, lobular mass (12.6×9.7×12 cm) of the greater curvature of the stomach. The patient underwent en bloc sphenoid gastrectomy, splenectomy, and caudal pancreatectomy. The histopathologic examination revealed findings compatible with a gastrointestinal stromal tumor located at the stomach, with low-grade malignancy (G1) and T4N0 according to TNM classification. He was discharged from the hospital on the 7th postoperative day. CONCLUSIONS GISTs are uncommon tumors of the gastrointestinal system that usually do not invade neighboring organs or develop distant metastases; therefore, local resection is usually the treatment of choice. However, in cases of large GISTs that are adherent to neighboring organs, en bloc resection and resection of adjacent organs may be inevitable.

A Rare Case of Gastric Schwannoma: A Case Report and Literature Review

In general, schwannoma is a benign and slow-glowing neoplasm that rarely occurs in the gastrointestinal tract as a submucosal tumor (SMT), with the most common site being the stomach. As gastric schwannoma (GS) is a rare tumor, there is limited data in the literature about its clinical features. The diagnosis of schwannoma can only be made by pathological examination with positive staining for S-100 protein. It is necessary to obtain an accurate diagnosis to introduce optimal treatment options preoperatively. However, a precise diagnosis of GS is difficult, even with modern imaging techniques. On the other hand, a complete resection with a negative surgical margin (R0) of GS is considered the best treatment, with an excellent prognosis. We present a case of a 66-year-old female patient who underwent laparoscopic-assisted wedge gastrectomy for gastric SMT, pathologically diagnosed as GS, with positive staining for S-100 protein and negative for c-kit and CD34. At 12-month follow-up after surgery, there was no recurrence or metastasis of GS. Our treatment is appropriate and effective in case of GS exceeding 50 mm.