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

The Role of Hospital Transfer in Reexamination Computed Tomography Scans: A Nationwide Cohort Study of Gastric Cancer Patients Undergoing Surgery

Because the high-cost of medical imaging can cause a tremendous economic burden across the health care system, we investigated factors associated with taking additional computed tomography (CT) scans. Data of gastric cancer patients were eligible for analysis if the patient underwent a gastrectomy during the study period (2002–2013). We defined initial CT scans as those taken within 90 days from the surgery date. If there was an additional CT scan between the date of an initial CT scan and the surgery date, we regarded it as a reexamination. We used multivariate logistic regression analysis for reexamination CT scans. Among 3342 gastrectomy patients, 1165 participants underwent second CT scans. Transfer experience (adjusted odds ratio (OR) = 23.87, 95% confidence interval (CI) = 18.15–31.39) was associated with higher OR for reexamination. Among transferred patients, an increased number per 100 beds at the initial CT hospital was associated with a decreased OR for reexamination (OR = 0.88, 95% CI = 0.83–0.94), but increased beds in surgery hospitals was related to an increased OR for reexamination (OR = 1.29, 95% CI = 1.20–1.36). In our study, transfer experience, initial CT scan in a low-volume hospital, and surgical treatment in a high-volume hospital were associated with reexamination CT scans.

Laparoscopic resection is better than endoscopic dissection for gastric gastrointestinal stromal tumor between 2 and 5 cm in size: a case-matched study in a gastrointestinal center

BACKGROUND

The feasibility of endoscopic dissection for gastric gastrointestinal stromal tumor (gGIST) between 2 and 5 cm in size has been demonstrated. However, its impact on short-term and long-term outcomes, compared with laparoscopic resection, is unknown. The purpose of this study was to compare short-term and long-term outcomes between laparoscopic resection and endoscopic dissection for 2-5-cm gGIST.

METHODS

A case-matched study was performed using the propensity score. To overcome selection bias, we performed a 1:1 match using six covariates, including age, sex, BMI, ASA score, tumor size, and tumor location. Short-term and long-term outcomes between laparoscopic resection and endoscopic dissection were compared.

RESULTS

A total of 210 patients with 2-5-cm gGIST were enrolled between 2006 and 2017 in our gastrointestinal center. According to the intention-to-treat approach, 165 patients underwent laparoscopic resection, and 45 patients underwent endoscopic dissection. After the propensity score, 45 pairs were balanced and analyzed. There was no significant difference in the baseline characteristics between the laparoscopic and endoscopic groups after matching. The rate of complications was significantly higher in the endoscopic group compared with the laparoscopic group (P < 0.001). Perforations occurred in 16 patients in the endoscopic group (16/45, 35.6%). The postoperative hospital stay was significantly longer in the endoscopic group compared with the laparoscopic group (P < 0.001). There was no significant difference between the two groups in disease-free survival or overall survival.

CONCLUSION

Laparoscopic resection is better than endoscopic dissection for 2-5-cm gGIST because of the lower complication rate and shorter hospital stay.

Excision of a Large Gastrointestinal Stromal Tumour Following 16 Months of Neoadjuvant Therapy with Imatinib (Case Report)

Introduction

Although the standard treatment for stromal tumours is surgery, in locally advanced forms, it is often necessary to achieve tumour downstaging to improve surgical outcomes. Neoadjuvant treatment in gastrointestinal stromal tumours (GISTs) with tyrosine kinase inhibitors, including imatinib, has been shown to be effective in several studies, but the duration of this treatment is still a subject of debate.

Case report

We report a case of a large GIST of the stomach in a 51-year-old patient with atypical presentation that was initially unresectable. Neoadjuvant treatment with imatinib for 16 months resulted in a good response, allowing secondary surgical excision.

Conclusion

Imatinib in neoadjuvant therapy should be continued as long as there is a good response and tolerance to the medication to obtain tumour downsizing compatible with carcinologic excision.

Electronic supplementary material

The online version of this article (10.1007/s40487-019-00101-4) contains supplementary material, which is available to authorized users.

Gastrointestinal stromal tumor: epidemiology, diagnosis, and treatment

PURPOSE OF REVIEW

The purpose of this review is to review the past year's literature to provide comprehensive information to researchers, physicians, and the general public regarding the epidemiology, diagnosis, and treatment of gastrointestinal stromal tumors (GISTs). Common ground as well as divergent viewpoints will be highlighted and discussed.

RECENT FINDINGS

The diagnosis of GISTs may involve imaging tests such as computed tomorgraphy scan and MRI, endoscopy with or without endoscopic ultrasound, and biopsy. Only biopsy, however, can yield a positive diagnosis. As most GISTs express KIT protein, immunostaining for KIT and/or molecular genetic testing for mutations in KIT can diagnose 95% of GISTs. Regorafenib, a drug that inhibits various protein genes that lead to GIST development is a relatively new treatment modality.

SUMMARY

The current review should enable clinicians to best select the diagnostic and treatment approaches to GIST.

Clinical feasibility and safety of third space robotic and endoscopic cooperative surgery for gastric gastrointestinal stromal tumors dissection : A new surgical technique for treating gastric GISTs

Background

Surgical management of gastric gastrointestinal stromal tumors (GISTs) has evolved towards minimal invasiveness. Laparoscopic wedge resection and laparoscopic and endoscopic cooperative surgery had been considered as standard surgical treatments for gastric GISTs > 2 cm. However, stomach deformation and the full-thickness gastric defect caused by these procedures may increase the risk of morbidity. To address these problems, we developed a novel technique, third space robotic and endoscopic cooperative surgery (TS-RECS), which could dissect the tumor entirely while preserving the intact mucosal layer. Here we performed a prospective evaluation of the feasibility and safety of TS-RECS.

Methods

Patients with gastric GISTs were recruited between April 2018 and April 2019. During the operation, the gastric GIST was located by endoscopic view firstly and the submucosal injection was performed. The tumor was then dissected through robotic surgery. Clinicopathological characteristics, operative data, adverse events, and follow-ups were prospectively collected and analyzed.

Results

A total of 20 patients with gastric GISTs received TS-RECS. The mean tumor size was 33.0 ± 7.3 mm. R0 resection was achieved in all patients with a median operation time of 115 min and a median blood loss of 20 ml. The integrity of mucosal layer was maintained in 95% (19/20) of the patients. All patients started oral diet on postoperative day 1 or 2, staying in the hospital for a median of 6 days after surgery. There were no major adverse events. Local or distant recurrences were not observed during a median follow-up period of 10 months.

Conclusions

Our study suggests that TS-RECS appears to be a feasible and safe technique which could be an alternative method for resecting gastric GISTs > 2 cm.

Clinical Trials

ClinicalTrials.gov NCT03804762.

Electronic supplementary material

The online version of this article (10.1007/s00464-019-07223-w) contains supplementary material, which is available to authorized users.

Combination of laparoscopic and endoscopic approaches for neoplasia with non-exposure technique (CLEAN-NET) for gastric submucosal tumors: updated advantages and limitations

Laparoscopic and endoscopic cooperative surgery (LECS) for gastric submucosal tumors (SMTs) has been developed under the concept of resecting gastric tumors with both complete curability and preserving organ functions. Precise resection is obtained by classical LECS, however, concerns regarding intraoperative bacterial infection and dissemination of the tumor cells into the abdominal cavity by LECS with exposure technique still remain. To prevent these concerns, several LECS-related procedures with non-exposure techniques, such as combination of laparoscopic and endoscopic approaches for neoplasia with non-exposure technique (CLEAN-NET) and non-exposed endoscopic wall-inversion surgery (NEWS), have been reported to be safe and feasible. Classical LECS, CLEAN-NET, and NEWS have the same concept, however, each has its own different characteristic procedures; exposure or non-exposure technique, inversion of the tumor into or outer the lumen, retrieval of tumor per oral or through the abdominal cavity, and dominance in the role of the endoscopist or the laparoscopic surgeon. Familiarization with these procedure details is important to understand their indications, advantages and limitations, resulting in providing a tailored minimally invasive surgery for patients. The main scope of this review article is to introduce readers to the clinical application, procedure, and results of CLEAN-NET, both from previous literatures and from our experience, as well as to offer a closer look at its advantages and limitations while comparing with other LECS procedures from the viewpoint of introducing CLEAN-NET first.

A novel technique for removing large gastric subepithelial tumors with ESD method in the subcardia region

Previously, patients with tumors larger than 4 cm in sub-cardia region usually received open gastrectomy. Due to its anatomic features, the cardia is often considered as a contraindicated area for endoscopic resection. Herein, we report a novel technique of endoscopic submucosal dissection (ESD) which facilitates the removal of gastric subepithelial tumors (SMTs) larger than 4 cm in the subcardia and fundus region. This is a retrospective case series of patients with SMTs larger than 4 cm in the subcardia and fundus regions who received the novel procedure of ESD between October 2015 and October 2016. The novel procedure of ESD involved a median linear incision of the mucosa being made in the central area of the tumor, followed by the submucosal dissection. The residual defect was finally closed using titanium endoclips. The endoscopical outcomes, histopathological findings as well as other complications were assessed. Eight patients fulfilled the entry criteria. The mean lesion size was 45.6±7.5 mm (range: 40.0-65.0 mm), and the mean operating time was 83±13 min (range: 60-100 min). The en bloc resection rate was 100%. Although perforations occurred in 5 out of 8 patients, they were successfully closed with endoclips. The median length of inpatient hospital stay was 6 days (range: 5-8 days). No patients needed further gastrectomy. The median follow-up was 36 months and none of the patients developed local recurrence or distant metastasis. The advanced procedure of ESD is feasible and safe for tumors more than 4 cm in the subcardia region. It could be applied as a novel technique for treating patient without surgical interventions.

Regorafenib regresses an imatinib-resistant recurrent gastrointestinal stromal tumor (GIST) with a mutation in exons 11 and 17 of c-kit in a patient-derived orthotopic xenograft (PDOX) nude mouse model

Gastrointestinal stromal tumor (GIST) with a mutation in exons 11 and 17 of c-kit is a rare type of sarcoma. The aim of this study was to determine drug sensitivity for a regionally-recurrent case of GIST using a patient-derived orthotopic xenograft (PDOX) model. The PDOX model was established in the anterior wall of the stomach. GIST PDOX models were randomized into 5 groups of 6 mice each when the tumor volume reached 60 mm³: G1, control group; G2, imatinib group (oral administration (p.o.), daily, for 3 weeks); G3, sunitinib group (p.o., daily, for 3 weeks); G4, regorafenib (p.o., daily, for 3 weeks); G5, pazopanib (p.o., daily, for 3 weeks). All mice were sacrificed on day 22. Tumor volume was evaluated on day 0 and day 22 by laparotomy. Body weight were measured 2 times per week. Though regorafenib is third-line therapy for GIST, it was the most effective drug and regressed the tumor significantly (p < 0.001). Sunitinib suppressed tumor growth compared to the control group (p = 0.002). Imatinib, first-line therapy for GIST, and pazopanib did not have significant efficacy compared to the control group (p = 0.886, p = 0.766). The implications of this result is discussed for GIST patients.

Digital image analysis-based scoring system for endoscopic ultrasonography is useful in predicting gastrointestinal stromal tumors

BACKGROUND

When gastric mesenchymal tumors (GMTs) measuring 2-5 cm in size are found, whether to undergo further treatment or not is controversial. Endoscopic ultrasonography (EUS) is useful for the evaluation of malignant potential of GMTs, but has limitations, such as subjective interpretation of EUS images. Therefore, we aimed to develop a scoring system based on the digital image analysis of EUS images to predict gastrointestinal stromal tumors (GISTs).

METHODS

We included 103 patients with histopathologically proven GIST, leiomyoma or schwannoma on surgically resected specimen who underwent EUS examination between January 2007 and June 2018. After standardization of the EUS images, brightness values, including the mean (T_mean), indicative of echogenicity, and the standard deviation (T_SD), indicative of heterogeneity, in the tumors were analyzed.

RESULTS

Age, T_mean, and T_SD were significantly higher in GISTs than in non-GISTs. The sensitivity and specificity were almost optimized for differentiating GISTs from non-GISTs when the critical values of age, T_mean, and T_SD were 57.5 years, 67.0, and 25.6, respectively. A GIST-predicting scoring system was created by assigning 3 points for T_mean ≥ 67, 2 points for age ≥ 58 years, and 1 point for T_SD ≥ 26. When GMTs with 3 points or more were diagnosed as GISTs, the sensitivity, specificity, and accuracy of the scoring system were 86.5%, 75.9%, and 83.5%, respectively.

CONCLUSIONS

The scoring system based on the information of digital image analysis is useful in predicting GISTs in case of GMTs that are 2-5 cm in size.

Pancreaticoduodenectomy versus limited resection for duodenal gastrointestinal stromal tumors: a systematic review and meta-analysis

Background

By comparing the long-term prognostic outcomes after pancreaticoduodenectomy (PD) and limited resection (LR), this study aimed to investigate the optimal surgical modality for duodenal gastrointestinal stromal tumors (GISTs).

Methods

Two authors independently searched PubMed, Web of Science, Embase, and the Cochrane Library for published articles comparing the long-term prognostic and clinicopathological factors of duodenal GIST patients undergoing PD versus LR. Relevant information was extracted and analyzed.

Results

After screening, 10 items comprising 623 cases were eventually included. This meta-analysis explicitly indicated that PD treatment was associated with worse long-term prognosis (hazard ratio = 1.93; 95% confidence interval [CI], 1.39–2.69; p < 0.001; I² = 0) and more complications (odds ratio [OR] = 2.90; 95% CI, 1.90–4.42; p < 0.001; I² = 10%) than LR treatment. Nevertheless, for duodenal GISTs, PD was related to the following clinicopathological features: invasion of the second part of the duodenum (OR = 3.39; 95% CI, 1.69–6.79; p < 0.001; I² = 50%), high-degree tumor mitosis (> 5/50 high-power fields; OR = 2.24; 95% CI, 1.42–3.52; p < 0.001; I² = 0), and high-risk classification (OR = 3.17; 95% CI; 2.13–4.71; p < 0.001; I² = 0).

Conclusions

Since PD is associated with worse long-term prognosis and more complications, its safety and efficacy should be ascertained. Our findings recommend the use of LR to obtain negative incision margins when conditions permit it.

Electronic supplementary material

The online version of this article (10.1186/s12893-019-0587-4) contains supplementary material, which is available to authorized users.

Endoscopic Ultrasound-Guided Fine Needle Aspiration and Biopsy in Gastrointestinal Subepithelial Tumors

The incidence of asymptomatic and incidentally found upper gastrointestinal subepithelial tumors (SETs) is increasing with the implementation of national cancer screening and the development of high-resolution endoscopy in Korea. However, endoscopy alone cannot be used to determine whether SETs are benign or malignant. Endoscopic ultrasound (EUS) is used to further characterize these lesions through the examination of their layered structure, internal echogenicity, size, and relationship to the extramural structure. These provide additional information on whether the lesion is benign or malignant. Nevertheless, the sensitivity and specificity of EUS alone in predicting malignancy is unsatisfactory. Recent guidelines have recommended deciding the timing of EUS-fine needle aspiration and biopsy (EUS-FNA/B) for SETs based on tumor size, malignant features on endoscopy, and high-risk features on EUS. The diagnostic accuracy of EUS-FNA/B is reportedly influenced by factors including needle size, number of needle passes, use of suction, use of a stylet in the needle assembly, fanning technique, availability of an on-site cytopathologist, and experience of the endosonographer. Therefore, according to the characteristics of the SETs, various subsequent methods and techniques should be appropriately employed to improve the diagnostic yield of EUS-FNA/B.

Building CT Radiomics-Based Models for Preoperatively Predicting Malignant Potential and Mitotic Count of Gastrointestinal Stromal Tumors

PURPOSE: To build radiomic prediction models using contrast-enhanced computed tomography (CE-CT) to preoperatively predict malignant potential and mitotic count of gastrointestinal stromal tumors (GISTs). PATIENTS AND METHODS: A total of 333 GISTs patients were retrospectively included in our study. Radiomic features were extracted from the preoperative CE-CT images. According to postoperative pathology, patients were categorized by malignant potential and mitotic count, respectively. The most valuable radiomic features were chosen to build a logistic regression model to predict the malignant potential and a random forest classifier model to predict the mitotic count. The performance of radiomic models was assessed with the receiver operating characteristics curve. Our study further developed a radiomic nomogram to preoperatively predict malignant potential in a personalized way for patients with GISTs. RESULTS: The predictive model was built to discriminate high– from low–malignant potential GISTs with an area under the curve (AUC) of 0.882 (95% CI 0.823-0.942) in the training set and 0.920 (95% CI 0.870-0.971) in the validation set. Moreover, the other radiomic model was built to differentiate high– from low–mitotic count GISTs with an AUC of 0.820 (95% CI 0.753-0.887) in the training set and 0.769 (95% CI 0.654-0.883) in the validation set. CONCLUSION: The radiomic models using CE-CT showed a good predictive performance for preoperative risk stratification of GISTs and hold great potential for personalized clinical decision making.

Comparison between laparoscopic and endoscopic resections for gastric submucosal tumors

BACKGROUND/AIMS

Open resection/laparoscopic resection (LR) is the traditional treatment of gastric submucosal tumor (G-SMT). The endoscopic resection (ER) technology provides good results for G-SMT treatment but lacks sufficient evidence-based evidence. This retrospective study aimed to compare the clinical efficacy of ER [endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), and endoscopic full-thickness resection (EFR)] and LR [laparoscopic wedge resection (LWR) and laparoscopic subtotal gastrectomy (LSG)] for G-SMT.

PATIENTS AND METHODS

From January 2013 to January 2017, data of patients with G-SMT with tumor diameter <5 cm were collected from the database of The Affiliated Hospital of Qingdao University and classified based on surgical methods. Demographics, tumor characteristics, surgical outcomes, complications and tumor recurrence were recorded and compared.

RESULTS

Overall, 275 patients with G-SMT were enrolled: 152 underwent ER (ESD, n = 65; ESE, n = 23; EFR, n = 61) and 123 underwent LR (LWR, n = 93; LSG, n = 30). Age, sex, R0 resection rate, tumor location, type, recurrence and complications were not statistically significant (P > 0.05). The ER group had a significantly higher percentage of intraluminal tumor (94.1% vs 62.4%) and smaller tumor size (1.8 ± 0.8 vs 3.4 ± 1.2 cm) than the LR group. The ER group had less muscular tumors than the LR group (54.6% vs 70.7%). The ER group had no serosal tumor. The ER group had shorter hospitalization time, postoperative hospital stay and diet recovery time. The LR group had shorter operation time, less cost and less blood loss.

CONCLUSION

ER and LR are safe and effective treatments for SMT. For small intraluminally growing SMT, ER is better than LR.

Fine-needle biopsy is superior to fine-needle aspiration of suspected gastrointestinal stromal tumors: a large multicenter study

Background and study aims  There are numerous studies published on the diagnostic yield of the new fine-needle biopsy (FNB) needles in pancreas masses. However, there are limited studies in suspected gastrointestinal stromal tumors (GIST lesions). The aim of this study was to evaluate the diagnostic yield of a new fork-tip FNB needle. Patients and methods  This was a multicenter retrospective study of consecutive patients from prospectively maintained databases comparing endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) versus endoscopic ultrasound-guided FNB (EUS-FNB) using the fork-tip needle. Outcomes measured were cytopathology yield (ability to obtain tissue for analysis of cytology), ability to analyze the tissue for immunohistochemistry (IHC yield), and diagnostic yield (ability to provide a definitive diagnosis). Results  A total of 147 patients were included in the study of which 101 underwent EUS-FNB and 46 patients underwent EUS-FNA. Median lesion size in each group was similar (21 mm vs 25 mm, P  = 0.25). Cytopathology yield, IHC yield, and diagnostic yield were 92 % vs 46 % ( P  = 0.001), 89 % vs 41 % ( P  = 0.001), and 89 % vs 37 % ( P  = 0.001) between the FNB and FNA groups, respectively. Median number of passes was the same between the two groups at 3.5. Conclusion  EUS-FNB is superior to EUS-FNA for diagnostic yield of suspected GIST lesions. This should be confirmed with a prospective study.

Gastrointestinal Stromal Tumor in a Patient with Neurofibromatosis Type 1 That Was Successfully Treated with Regorafenib

An unconscious 55-year-old man with a history of neurofibromatosis type 1 (NF1) was transported to the emergency department and was diagnosed with acute renal failure owing to a large bladder tumor. A submucosal tumor was also identified in the duodenum. The patient was diagnosed with a primary gastrointestinal stromal tumor (GIST) of the bladder and duodenum. After six cycles of regorafenib therapy, 18F-fluorodeoxyglucose accumulation in the duodenal GIST on positron emission tomography-computed tomography (PET-CT) showed a partial metabolic response. Currently, no standard drug therapy for unresectable or relapsed NF1-associated GIST has been established. Regorafenib may thus be considered as and appropriate initial therapy.

Effect of the imatinib treatment regimen on the postoperative prognosis of patients with high-risk gastrointestinal stromal tumors

Background: Surgical resection is the standard treatment for localized and potentially resectable gastrointestinal stromal tumors (GISTs), If the postoperative pathology diagnosis indicates that patients are at high risk of recurrence, they should be treated with imatinib. Even though the introduction of imatinib substantially improved the outcome of GIST patients, it is unclear whether different imatinib treatment regimens affect patients' survival. Methods: This retrospective study included 120 patients who underwent tumor resection for high-risk GISTs between January 2009 and October 2018. The patients were divided into three groups: one group of patients received postoperative imatinib adjuvant therapy regularly (regular treatment group); the second group was not treated with imatinib until they were found to have disease progression (observation group); the third group was treated with postoperative imatinib adjuvant therapy irregularly (irregularly treatment group). The progression-free survival (PFS) and overall survival (OS) were compared between the three groups, and the prognostic risk factors were analysed by the Cox regression model. Results: The median PFS was 45 months (range: 25-59). The 3- and 5-year PFS values were 71.3% and 49.9%, respectively. The PFS in the regular group was longer than in the observation group and irregular group (P<0.001). The median OS was 59 months (range:47-78). The 3- and 5-year OS values were 91.6% and 84.2%, respectively. There were no differences in OS among the three groups (P=0.150). The extent of radical resection (P<0.001) and intraoperative tumor rupture (P=0.005) were independent prognostic factors influencing OS. Conclusions: Irregular administration of imatinib was associated with a worse PFS, but it did not affect the OS of patients with high-risk GISTs. Avoiding intraoperative tumor rupture and R0 resection were associated with better survival.

Multifocal gastrointestinal stromal tumor: A case report with CT, surgical, and histopathologic correlation

Mutifocal gatrointestinal stromal tumors (GISTs) are rare conditions that are usually associated with other syndromes or reported in pediatric cases. The sporadic form represents only 11% of GISTs. The imaging features on a contrast-enhanced computed tomography examination, surgery and histopathology of a rare case of a sporadic multifocal small bowel GISTs in an emergency setting are described. This case highlights how GISTs appearances on an imaging computed tomography may vary. Radiologists can have difficulty in defining the point of origin of large lesions. In our case, laparotomy open surgery was mandatory to figuring out the correct diagnosis.

Apatinib Treatment in Metastatic Gastrointestinal Stromal Tumor

Background: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. The clinical management of patients with metastatic GISTs is exceptionally challenging due to their poor prognosis. Apatinib is a multiple tyrosine kinase inhibitor. Here, we present the unique case with metastatic GISTs who derived clinical benefit from apatinib following the failure of imatinib and sunitinib.

Case presentation: A 57-year-old man was admitted to our hospital diagnosed with metastatic and recurrent GISTs following surgical resection. Fifty-four months after the first-line imatinib treatment, he developed progressive disease and then was treated with cytoreductive surgery combined with imatinib. Disease progression occurred after 7 months. He then received second-line sunitinib and achieved a progression-free survival of 11 months. Apatinib mesylate was then administered. Follow-up imaging revealed a stable disease. Progression-free survival following apatinib therapy was at least 8 months. The only toxicities were hypertension and proteinuria, which were both controllable and well-tolerated.

Conclusions: Treatment with apatinib provides an additional option for the treatment of patients with GISTs refractory to imatinib and sunitinib.

Downregulation of lncRNA CCDC26 contributes to imatinib resistance in human gastrointestinal stromal tumors through IGF-1R upregulation

Imatinib is the first line of therapy for patients with metastatic or gastrointestinal stromal tumors (GIST). However, drug resistance limits the long-term effect of imatinib. Long non-coding RNAs (lncRNAs) are emerging as key players in regulating drug resistance in cancer. In this study, we investigated the association between lncRNA CCDC26 and IGF-1R in GIST and their involvement in drug resistance. Considering the key role of lncRNAs in drug resistance in cancer, we hypothesized that IGF-1R is regulated by lncRNAs. The expression of a series of reported drug resistance-related lncRNAs, including CCDC26, ARF, H19, NBR2, NEAT1, and HOTAIR, in GIST cells treated with imatinib H19 was examined at various time-points by qRT-PCR. Based on our results and published literature, CCDC26, a strongly down-regulated lncRNA following imatinib treatment, was chosen as our research target. GIST cells with high expression of CCDC26 were sensitive to imatinib treatment while knockdown of CCDC26 significantly increased the resistance to imatinib. Furthermore, we found that CCDC26 interacted with c-KIT by RNA pull down, and that CCDC26 knockdown up-regulated the expression of IGF-1R. Moreover, IGF-1R inhibition reversed CCDC26 knockdown-mediated imatinib resistance in GIST. These results indicated that treatments targeting CCDC26-IGF-1R axis would be useful in increasing sensitivity to imatinib in GIST.

Gastrointestinal Stromal Tumors of the Stomach and Esophagus

Gastrointestinal stromal tumors (GISTs) arise anywhere along the gastrointestinal tract, most commonly as a result of c-kit or PDGFRA proto-oncogene mutations. Surgical resection is an important component of treatment. However, molecular profiling of GISTs has provided many insights into adjuvant and neoadjuvant therapy options. Imatinib, the most frequently studied medical therapy, has been shown in numerous studies to provide benefit to patients in both the neoadjuvant and adjuvant setting. Interval imaging is an important component of the treatment of GISTs and national surveillance recommendations should be followed.

Do GISTs Occur in Rats and Mice? Immunohistochemical Characterization of Gastrointestinal Tumors Diagnosed as Smooth Muscle Tumors in The National Toxicology Program

The majority of the tumors in the gastrointestinal (GI) tract of rats and mice, with spindle cell morphology, are diagnosed as smooth muscle tumors (SMTs). Similarly, several decades ago human GI tumors with spindle cell morphology were also diagnosed as SMTs. However, later investigations identified most of these tumors in humans as gastrointestinal stromal tumors (GISTs). The GISTs are considered to arise from the interstitial cells of Cajal located throughout the GI tract. Positive immunohistochemical staining with CKIT antibody is a well-accepted diagnostic marker for GISTs in humans. Since there is a considerable overlap between the histomorphology of SMTs and GISTs, it is not possible to distinguish them on hematoxylin and eosin stained sections. As a result, GISTs are not routinely diagnosed in toxicological studies. The current study was designed to evaluate the tumors diagnosed as leiomyoma or leiomyosarcoma in the National Toxicology Program's 2-year bioassays using CKIT, smooth muscle actin, and desmin immunohistochemistry. The results demonstrate that most of the mouse SMTs diagnosed as leiomyoma or leiomyosarcoma are likely GISTs, whereas in rats the tumors are likely SMTs and not GISTs.

CT Versus Endoscopic Ultrasound for Differentiating Small (2-5 cm) Gastrointestinal Stromal Tumors From Leiomyomas

OBJECTIVE. Abdominal CT or endoscopic ultrasound is recommended for the evaluation of gastric subepithelial tumors. However, few studies have compared the diagnostic performance of these two methods. We compared the diagnostic performance of CT versus endoscopic ultrasound for gastric subepithelial tumors smaller than 5 cm. We also identified significant CT findings associated with the diagnosis of gastrointestinal stromal tumors. MATERIALS AND METHODS. Seventy-one patients with pathologically proven gastric subepithelial tumors were enrolled. We examined the diagnostic performance of CT compared with endoscopic ultrasound. We analyzed CT findings, including the location, long diameter (LD), short diameter (SD), LD-SD ratio, contour, margin, growth pattern, degree and pattern of enhancement, attenuation value, intralesional necrosis, calcification, hemorrhage, surface dimpling, and perilesional lymph node. RESULTS. Endoscopic ultrasound had a sensitivity of 77.6%, specificity of 61.5%, PPV of 90.0%, NPV of 38.1%, and accuracy of 74.6%. CT had a sensitivity of 84.5%, specificity of 53.8%, PPV of 89.1%, NPV of 43.8%, and accuracy of 78.9%. Multivariate analysis revealed that the presence of intralesional necrosis (odds ratio [OR], 10.88; p = 0.037) and an LD-SD ratio less than 1.5 (OR, 32.37; p = 0.002) were independent CT findings for the diagnosis of gastrointestinal stromal tumors. CONCLUSION. CT is as effective as endoscopic ultrasound for the diagnosis of gastric subepithelial tumors smaller than 5 cm. Tumors with intralesional necrosis and an LD-SD ratio less than 1.5 may require further pathologic diagnosis.

Malignant jejunal gastrointestinal stromal tumor with history of prostate cancer: A case report

RATIONALE

The problem of the coexistence of gastrointestinal stromal tumor (GIST) with other neoplasms is complex, and carcinomas of prostate is one of the common types of GIST-associated cancers. Doubling time of GIST is about 3.9 months for high-risk GIST, and the treatment paradigm for GIST has required the integration of surgery and molecular therapy.

PATIENT CONCERNS

A 70-year-old man with postoperative history of prostate cancer experienced fast-growing malignant jejunal GIST with multiple peritoneal metastases within 1 year.

DIAGNOSES

Enhanced computed tomography (CT) detected a neoplasm of small intestine with multiple peritoneal nodules and postoperative pathology confirmed GIST.

INTERVENTIONS

Oral imatinib after surgery, at 400 mg per day, was used for 4 years.

OUTCOMES

The patient remains well, and the peritoneal nodules located in front of the rectum disappeared gradually.

LESSONS

Physicians should be aware of possibility of GIST in patients with prostate cancer and can perform abdominal examination in these patients. For postoperative patients with prostate cancer, an yearly or half-yearly abdominal and pelvic cavity examination can be performed. Suspicion and timely work-up is necessary in these postoperative prostate cancer patients, especially when they have abdominopelvic pain.

Adjuvant therapy with imatinib in gastrointestinal stromal tumors (GISTs)-review and perspectives

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the gastrointestinal (GI) tract. Most of them (>75%) are driven by an oncogenic initiating event involving activating mutations of the genes encoding for tyrosine kinase, KIT or platelet derived growth factor receptor alpha (PDGFRA). Efficacy of the tyrosine kinase Inhibitor imatinib is now well established for advanced disease. For localized GISTs, 3 years treatment is the recommended adjuvant therapy for high risk patients. Whether a longer duration and selection of patients for this adjuvant therapy in localized GISTs remains is not yet established (PERSIST-5 study). Similarly, it will be important to further refine the definition of the population of GIST patients at high risk of relapse including molecular criteria (Annals of Oncology, ESMO guidelines 2018). This review aims to describe current knowledges on the issue of adjuvant therapy of primary GISTs in view of available results.

Recurrent gastric volvulus associated with a gastrointestinal stromal tumor: A case report

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A 7-cm gastrointestinal stromal tumor (GIST) caused recurrent abdominal pain, apparently through gastric volvulus (GV).

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The risk of GV based on the size and location of a tumor is unknown.

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Prompt surgical intervention is indicated in cases of recurrent GV.

Introduction

Gastric volvulus (GV) is defined as a rotation of the stomach along its short or long axis leading to variable degrees of gastric outlet obstruction. Rotation of the stomach >180° may cause closed loop obstruction and possible strangulation, which often causes acute abdominal pain. Strangulation and gangrene of the twisted stomach sometimes occurs, which demands immediate surgical intervention. We report a case of acute gastric volvulus due to a gastrointestinal stromal tumor (GIST), with multiple recurrences, that eventually required emergency gastrectomy.

Presentation of the case

A 71-year-old woman with a history of recurrent epigastric pain, nausea, and anorexia was diagnosed to have a 70-mm sized submucosal tumor (SMT) in the lesser curvature of the stomach. An elective gastrectomy was planned; however, before the procedure, she visited the emergency room with acute recurrent epigastric pain associated with postural variations. Computed tomography (CT) revealed a GV and the tumor had shifted to the greater curvature. An emergency gastrectomy was performed. The postoperative course was uneventful and pathological examination revealed features consistent with that of GIST.

Discussion

GV with GIST has rarely been reported and risk factors such as size or localization are unknown. In this case, GV was probably caused by GIST of the stomach, which was large and heavy enough to rotate the gastric body around the mesenteroaxis.

Conclusion

Surgical intervention without delay should be planned in similar scenarios accounting for the risk of GV in GIST.

Surgical treatment of gastric GIST with acute bleeding using laparoscopic sleeve gastrectomy: A report of two cases

In this report, we want to emphasize how a laparoscopic bariatric surgical procedure, in experienced hands, has shown to be a valid alternative for the hemorrhage control and the removal of a gastrointestinal tumor in a life-threatening situation.

Gastrointestinal stromal tumor presenting as a rectovaginal septal mass: A case report and review of literature

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) arising from the gynecological tract are extremely rare. A case of GIST with an unusual presentation as a vaginal mass is presented with comprehensive literature review, aiming to gain a better understanding of the diagnostic and treatment strategy of the disease.

PATIENT CONCERNS

A 78-year-old woman presented with persistent vaginal bleeding and difficulty in micturition. Although the tumor mass was diagnosed, the results of preoperative evaluations are uncertain.

DIAGNOSIS

Preoperative evaluation included the computed tomography examination (a 6.3×5.3 cm cervical mass lesion with rectal and vaginal invasion), colonoscopy (an external compression with an intact mucosa), tumor markers, and biopsy (spindle cell tumor). Postoperative histopathology confirmed the diagnosis of GIST.

INTERVENTIONS

Posterior exenteration with complete resection was performed. The patient received postoperative adjuvant imatinib therapy.

OUTCOMES

The patient has survived without the disease for more than 3 years.

CONCLUSION

It is still a challenge to diagnose GISTs in women with rectovaginal mass preoperatively. Efforts should be made, including a high suspicion and an assistance of immunohistochemistry. A precise diagnosis may offer a better surgical and treatment plan, especially on the preservation of reproductive organs and accessibility of targeted therapy.

Impact of endoscopic ultrasound-guided fine-needle biopsy on the diagnosis of subepithelial tumors: A propensity score-matching analysis

BACKGROUND AND AIM

Immunohistological evaluations are essential for diagnosing subepithelial tumors (SET). However, endoscopic ultrasound-guided sampling using fine-needle aspiration (FNA) needles is limited in its ability to procure core tissue for immunostaining. Fine-needle biopsy (FNB) needles may mitigate this limitation. The present study aimed to examine the efficacy of FNB needles for procuring samples that enable the diagnosis of SET.

METHODS

One hundred sixty patients were included in the study and separated into those whose samples were obtained using FNB needles (FNB group) and those whose samples were procured using FNA needles (FNA group). Groups were compared regarding the conclusive diagnosis rate and unwarranted resection rate. Propensity score matching was introduced to reduce selection bias.

RESULTS

Rates at which conclusive diagnoses were reached through adequate immunohistological evaluations were 82% and 60% in the FNB and FNA groups, respectively; this difference was significant (P = 0.013). Unwarranted resection rate was significantly lower in the FNB group (2%) than in the FNA group (14%; P = 0.032). Multivariate analyses showed that lesions ≤20 mm were a significant risk factor for lower conclusive diagnosis rates following the use of FNB needles (P = 0.017).

CONCLUSIONS

Fine-needle biopsy needles can be useful for obtaining samples that facilitate the diagnosis of SET and for avoiding unwarranted resections. However, FNB needles may be less advantageous for small SET.

Lesion size determines diagnostic yield of EUS-FNA with onsite cytopathologic evaluation for upper gastrointestinal subepithelial lesions

BACKGROUND/AIMS

The aim of this study was to determine the diagnostic yield and factors influencing the diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for upper gastrointestinal (GI) subepithelial lesions (SELs) with rapid onsite cytopathologic evaluation.

MATERIALS AND METHODS

This is a single-center, retrospective study.

RESULTS

Among 22 patients who underwent EUS-FNA, a cytopathological diagnosis was reached in 16 (72.7%) patients. The EUS-FNA results were as follows: seven GISTs (31.8%), six leiomyomas (27.2%), four non-diagnostics (18%), two duplication cysts (9%), two spindle cell tumor (9%), and one ectopic pancreas (4.5%). The long-axis size was > 20 mm in 12 patients (average size: 31.3 ±9.3 mm) and < 20 mm (average size: 16.6 ±2.5 mm) in 10 patients. Diagnostic accuracy of EUS-FNA from lesions < 20 mm was 50% (5/10 lesions), and of lesions > 20 mm was 91.6% (11/12 lesions) (Fisher's exact test; p=0.028). Six patients underwent surgical resection. Surgical pathology results of five lesions (four GIST, one leiomyoma) were consistent with cytopathology results (83.3%).

CONCLUSION

The diagnostic yield of EUS-FNA of the upper GI SELs with an onsite cytopathologic interpretation was 72.7%. Lesion size < 2 cm significantly reduces the diagnostic yield of EUS-FNA for the upper GI SELs.

PRE-OPERATIVE GASTRIC GIST DOWNSIZING: THE IMPORTANCE OF NEOADJUVANT THERAPY

Introduction:

Gastric gastrointestinal tumors (GIST) are a rare and usually asymptomatic neoplasm that can present as abdominal mass in more advanced scenarios. Since surgical resection is the main aspect of the treatment, locally advanced tumors require multivisceral resection and, therefore, higher postoperative morbidity and mortality.

Objective:

To perform a review the literature on the topic, with emphasis on the neoadjuvant therapy.

Methods:

Literature review on the Medline database using the following descriptors: gastrointestinal stromal tumors, neoadjuvant therapy, imatinib mesylate and molecular targeted therapy.

Results:

Surgical resection remains the cornerstone for the treatment of GISTs; however, tyrosine kinase inhibitors have improved survival as an adjuvant therapy. More recently, neoadjuvant therapy have been described in the treatment of locally advanced tumors in order to avoid multivisceral resection.

Conclusion:

Despite surgical resection remains as the most important aspect of the treatment of GISTs, adjuvant and neoadjuvant therapy with tyrosine kinase inhibitors have shown to both improve survival and resectability, respectively.

Relationship between R1 resection, tumour rupture and recurrence in resected gastrointestinal stromal tumour

Background

According to guidelines, adjuvant treatment or re-excision should be considered after R1 resection of gastrointestinal stromal tumours (GISTs). However, the prognostic significance of R1 resection is uncertain and tumour rupture confounds its assessment. Here, the impact of positive margins was examined and related to rupture in a population-based cohort.

Methods

Patients undergoing surgery for non-metastatic GIST since 2000 were identified in the sarcoma database of Oslo University Hospital. Margins were coded according to the residual tumour (R) classification and tumour rupture defined according to the Oslo criteria.

Results

Among 410 patients, there were 47 who underwent R1 resection and 52 had tumour rupture. The relative risk of R1 resection with rupture was 3·55 (95 per cent c.i. 2·09 to 6·03; P &lt; 0·001). In patients without rupture, there was no difference in estimated 5-year recurrence-free survival after R0 versus R1 resection (87·6 versus 93 per cent; hazard ratio (HR) 0·71, 95 per cent c.i. 0·17 to 2·98; P = 0·638); nor was there any difference among patients with rupture (37 versus 31 per cent; HR 1·31, 0·68 to 2·54; P = 0·420). In multivariable analysis, tumour rupture but not R1 resection was independently associated with recurrence. Twenty-four patients at very low, low or intermediate risk did not receive adjuvant imatinib after R1 resection and remained recurrence-free.

Conclusion

Positive resection margins are strongly associated with tumour rupture. R1 resection does not independently influence prognosis. Adjuvant imatinib may not be justified after R1 resection in the absence of tumour rupture or other high-risk features.

Laparoscopic and endoscopic cooperative surgery for gastric tumors: Perspective for actual practice and oncological benefits

Laparoscopic and endoscopic cooperative surgery (LECS) is a surgical technique that combines laparoscopic partial gastrectomy and endoscopic submucosal dissection. LECS requires close collaboration between skilled laparoscopic surgeons and experienced endoscopists. For successful LECS, experience alone is not sufficient. Instead, familiarity with the characteristics of both laparoscopic surgery and endoscopic intervention is necessary to overcome various technical problems. LECS was developed mainly as a treatment for gastric submucosal tumors without epithelial lesions, including gastrointestinal stromal tumors (GISTs). Local gastric wall dissection without lymphadenectomy is adequate for the treatment of gastric GISTs. Compared with conventional simple wedge resection with a linear stapler, LECS can provide both optimal surgical margins and oncological benefit that result in functional preservation of the residual stomach. As technical characteristics, however, classic LECS involves intentional opening of the gastric wall, resulting in a risk of tumor dissemination with contamination by gastric juice. Therefore, several modified LECS techniques have been developed to avoid even subtle tumor exposure. Furthermore, LECS for early gastric cancer has been attempted according to the concept of sentinel lymph node dissection. LECS is a prospective treatment for GISTs and might become a future therapeutic option even for early gastric cancer. Interventional endoscopists and laparoscopic surgeons collaboratively explore curative resection. Simultaneous intraluminal approach with endoscopy allows surgeons to optimizes the resection area. LECS, not simple wedge resection, achieves minimally invasive treatment and allows for oncologically precise resection. We herein present detailed tips and pitfalls of LECS and discuss various technical considerations.

Clinical Overview of GIST and Its Latest Management by Endoscopic Resection in Upper GI: A Literature Review

Aims

To review the clinical presentation, diagnosis, assessment of risk of malignancy, and recent advances in management (mainly focusing on the role of endoscopic resection) of gastrointestinal stromal tumors (GISTs) in upper GI.

Method

We searched Embase, Web of science, and PubMed databases from 1993 to 2018 by using the following keywords: “gastrointestinal stromal tumors,” “GIST,” “treatment,” and “diagnosis.” Additional papers were searched manually from references of the related articles.

Findings

The improvement of endoscopic techniques in treating upper gastrointestinal subepithelial tumors especially gastrointestinal tumors has reduced the need for invasive surgery in patients unfit for surgery. Many studies have concluded that modified endoscopic treatments are effective and safe. These treatments permit minimal tissue resection, better dissection control, and high rates of en bloc resection with an acceptable rate of complications.

Standard Approach to Gastrointestinal Stromal Tumors - Differences between China and Europe

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. With the considerable research and application of molecular-targeted therapy for GISTs in the last two decades, GISTs have become a model of multidisciplinary oncological treatment. Although Western clinical guidelines are available for GISTs, such as those by the European Society of Medical Oncology (ESMO), the clinical situations in China are different from those in European countries. There are distinct differences between the clinical practice, diagnostic methods, surgical approach, and availability of new targeted agents in China and those in Europe. This review summarizes the Chinese GIST consensus guidelines compared to the European ones, which may provide an optimal approach to the diagnosis and management of GIST patients.

Evaluation of Clinical Plus Imaging Features and Multidetector Computed Tomography Texture Analysis in Preoperative Risk Grade Prediction of Small Bowel Gastrointestinal Stromal Tumors

OBJECTIVE

This study aimed to evaluate the prediction roles of clinical plus imaging features and multidetector computed tomography (MDCT) texture analysis in preoperative risk grade classification of small bowel (SB) gastrointestinal stromal tumors (GISTs).

METHODS

This study included 213 SB GIST patients. Clinical features and MDCT imaging findings were reviewed. Tumor risk stratifications were determined according to modified National Institutes of Health criteria. Random forest models were performed to evaluate the correlation of risk stratification.

RESULTS

The model of clinical plus imaging findings showed an area under receiver operating characteristic curve (AUC) of 92.0%. The AUC of texture analysis based on MDCT portal phase was 93.3%, without statistical difference from that of clinical plus imaging model (P = 0.378). The AUC of the model combined clinical plus imaging features and MDCT texture analysis was 94.3%, which was significantly higher than the AUC of clinical imaging model (P = 0.042).

CONCLUSION

Texture analysis may become an important comprehensive tool for preoperative risk stratification of SB GISTs.

Imaging pediatric gastrointestinal stromal tumor (GIST)

BACKGROUND

Gastrointestinal stromal tumors (GIST) are extremely rare in children. Imaging plays a key role in staging and monitoring therapy (surgical and with tyrosine kinase inhibitors). The vast majority of articles addressing imaging of GIST base on adults and are based on CT. The subtype "pediatric GIST" - if at all - is only mentioned in a dependent clause. Although the imaging features in children and adults are similar, histology, clinical course and thus imaging approach are different.

METHODS

A PubMed search using the search terms "Gastrointestinal stromal tumor, GIST, WT GIST, children, pediatric, carney's triad, imaging, staging, follow-up, MRI, CEUS, ultrasonography, Positron emission tomography" was conducted. Studies that reported on laparoscopy, endoscopy and surgical techniques only were excluded.

RESULTS

Based on our selective literature review, we present alternative radiological imaging strategies using MRI, contrast enhanced ultrasound (CEUS) and PET-CT to stage and follow-up pediatric GIST patients. As pediatric GIST often is a chronic disease, minimizing exposure to ionizing radiation is mandatory.

CONCLUSION

MRI, contrast enhanced ultrasound and PET-CT instead of CT are the imaging modalities to evaluate pediatric GIST.

TYPE OF STUDY

Systematic review LEVEL OF EVIDENCE: III.

Imatinib rechallenge in patients with advanced gastrointestinal stromal tumors following progression with imatinib, sunitinib and regorafenib

BACKGROUND

Rechallenge with imatinib is an option in advanced gastrointestinal stromal tumor (GIST) patients following progression with standard tyrosine-kinase inhibitors (TKIs), imatinib, sunitinib and regorafenib. We retrospectively collected data from metastatic Italian GIST patients treated with imatinib resumption after progression to conventional TKIs.

METHODS

A total of 104 eligible advanced GIST patients, previously treated with imatinib, sunitinib and regorafenib, were collected from six referral Italian institutions. Mutational analysis was recorded and correlated with survival and response according to RECIST 1.1 or CHOI criteria.

RESULTS

Overall, 71 patients treated with imatinib 400 mg as rechallenge were included. Mutational status was available in all patients. The median follow up was 13 months. In patients who received a rechallenge therapy, the median time to progression (TTP) was 5.4 months [95% confidence interval (CI) 1.9-13.5] and overall survival (OS) was 10.6 months (95% CI 2.8-26.9). A correlation between mutational status, response rate, TTP and OS was not found but comparing deleted versus nondeleted KIT exon 11 patients, a significant difference was identified in terms of TTP and OS (p = 0.04 and p = 0.02, respectively).

CONCLUSIONS

Our retrospective data confirm that imatinib rechallenge is a reasonable option in advanced GIST. The prognostic value of the specific KIT mutations was confirmed in our series.

Small bowel gastrointestinal stromal tumor: a retrospective study of 32 cases at a single center and review of the literature

Background

Gastrointestinal stromal tumor (GIST) is a rare tumor of the small bowel, which can be difficult to diagnose and has a varied clinical outcome.

Purpose

This is a retrospective review of the diagnosis, management, and clinical outcome of 32 patients diagnosed with primary small bowel GIST from a single center and a comparison of the findings with previously published cases.

Patients and methods

Retrospective review of data from patient clinical records, endoscopic and imaging findings, surgical procedures, tumor histology and immunohistochemistry, and clinical outcome was conducted.

Results

Data of 32 patients with a median age of 56 years including 50% men and women were reviewed. The majority (29/32) were symptomatic at presentation, with the main symptom being gastrointestinal bleeding (15/32). Imaging detection rates included ultrasound (0%), magnetic resonance imaging (0%), computed tomography (54.8%), computed tomography angiography (71.4%), and double-balloon enteroscopy (88.9%). The mean tumor diameter was 5.3 cm; 4 tumors were located in the duodenum, 21 in the jejunum, and 7 in the ileum. Based on the tumor size and mitotic index, 5 (15.6%), 15 (46.9%), 0 (0%), and 12 (37.5%) patients were classified into very low-risk, low-risk, intermediate-risk, and high-risk groups. Immunohistochemistry showed positive expression for CD117 (100%), CD34 (81.2%), DOG1 (93.8%), smooth muscle actin (37.5%), S100 (9.4%), and desmin (6.2%). Twenty-five patients (78.1%) were treated with open surgical tumor resection; seven patients (21.9%) underwent laparoscopic surgery. Postoperative complications that occurred in seven patients (21.9%) were resolved with conservative management. Four patients were treated with postoperative imatinib. At median follow-up of 30 months, two patients were died.

Conclusion

The findings from this case series, combined with the findings from previously published cases, provide an update on the current status of the diagnosis and the therapeutic approaches that might lead to improvement in prognosis for patients who present with primary small bowel GIST.

Radiomics nomogram for predicting the malignant potential of gastrointestinal stromal tumours preoperatively

OBJECTIVE

To develop and evaluate a radiomics nomogram for differentiating the malignant risk of gastrointestinal stromal tumours (GISTs).

METHODS

A total of 222 patients (primary cohort: n = 130, our centre; external validation cohort: n = 92, two other centres) with pathologically diagnosed GISTs were enrolled. A Relief algorithm was used to select the feature subset with the best distinguishing characteristics and to establish a radiomics model with a support vector machine (SVM) classifier for malignant risk differentiation. Determinant clinical characteristics and subjective CT features were assessed to separately construct a corresponding model. The models showing statistical significance in a multivariable logistic regression analysis were used to develop a nomogram. The diagnostic performance of these models was evaluated using ROC curves. Further calibration of the nomogram was evaluated by calibration curves.

RESULTS

The generated radiomics model had an AUC value of 0.867 (95% CI 0.803-0.932) in the primary cohort and 0.847 (95% CI 0.765-0.930) in the external cohort. In the entire cohort, the AUCs for the radiomics model, subjective CT findings model, clinical index model and radiomics nomogram were 0.858 (95% CI 0.807-0.908), 0.774 (95% CI 0.713-0.835), 0.759 (95% CI 0.697-0.821) and 0.867 (95% CI 0.818-0.915), respectively. The nomogram showed good calibration.

CONCLUSIONS

This radiomics nomogram predicted the malignant potential of GISTs with excellent accuracy and may be used as an effective tool to guide preoperative clinical decision-making.

KEY POINTS

• CT-based radiomics model can differentiate low- and high-malignant-potential GISTs with satisfactory accuracy compared with subjective CT findings and clinical indexes. • Radiomics nomogram integrated with the radiomics signature, subjective CT findings and clinical indexes can achieve individualised risk prediction with improved diagnostic performance. • This study might provide significant and valuable background information for further studies such as response evaluation of neoadjuvant imatinib and recurrence risk prediction.

Pediatric gastrointestinal stromal tumors-a review of diagnostic modalities

Gastrointestinal stromal tumors are exceedingly rare tumors in the pediatric population, as a result many clinicians either may never see this diagnosis or will encounter it only a few times throughout their careers. It is imperative in the pediatric population to follow appropriate steps to ensure a swift diagnosis and referral to specialized centers that are equipped with the multidisciplinary teams accustomed to treating rare diseases. This review aims to discuss the most recent data available on the diagnostic modalities utilized in cases of suspected Pediatric GIST.

Current treatment strategies in pediatric gastrointestinal stromal cell tumor

Gastrointestinal stromal tumors (GIST) are exceedingly rare tumors in the pediatric population. As a result, many clinicians either may never see this diagnosis or will encounter it only a few times throughout their careers. Additionally, the more we discover about this disease, it becomes evident that it represents a distinct clinical entity from adult GIST. Many of the treatments and strategies used to combat the adult tumor are either ineffective or may be harmful to the pediatric population with this disease. The unique tumor biology found in pediatric GIST necessitates unique approaches and treatment strategies in order to achieve the best clinical outcome. This review aims to discuss the most recent data available on the different therapeutic modalities utilized in cases of Pediatric GIST.

Current clinical management of gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are the most common malignant subepithelial lesions (SELs) of the gastrointestinal tract. They originate from the interstitial cells of Cajal located within the muscle layer and are characterized by over-expression of the tyrosine kinase receptor KIT. Pathologically, diagnosis of a GIST relies on morphology and immunohistochemistry [KIT and/or discovered on gastrointestinal stromal tumor 1 (DOG1) is generally positive]. The prognosis of this disease is associated with the tumor size and mitotic index. The standard treatment of a GIST without metastasis is surgical resection. A GIST with metastasis is usually only treated by tyrosine kinase inhibitors without radical cure; thus, early diagnosis is the only way to improve its prognosis. However, a GIST is usually detected as a SEL during endoscopy, and many benign and malignant conditions may manifest as SELs. Conventional endoscopic biopsy is difficult for tumors without ulceration. Most SELs have therefore been managed without a histological diagnosis. However, a favorable prognosis of a GIST is associated with early histological diagnosis and R0 resection. Endoscopic ultrasonography (EUS) and EUS-guided fine needle aspiration (EUS-FNA) are critical for an accurate diagnosis of SELs. EUS-FNA is safe and effective in enabling an early histological diagnosis and adequate treatment. This review outlines the current evidence for the diagnosis and management of GISTs, with an emphasis on early management of small SELs.

Neuroblastoma Origin and Therapeutic Targets for Immunotherapy

Neuroblastoma is a pediatric solid cancer of heterogeneous clinical behavior. The unique features of this type of cancer frequently hamper the process of determining clinical presentation and predicting therapy effectiveness. The tumor can spontaneously regress without treatment or actively develop and give rise to metastases despite aggressive multimodal therapy. In recent years, immunotherapy has become one of the most promising approaches to the treatment of neuroblastoma. Still, only one drug for targeted immunotherapy of neuroblastoma, chimeric monoclonal GD2-specific antibodies, is used in the clinic today, and its application has significant limitations. In this regard, the development of effective and safe GD2-targeted immunotherapies and analysis of other potential molecular targets for the treatment of neuroblastoma represents an important and topical task. The review summarizes biological characteristics of the origin and development of neuroblastoma and outlines molecular markers of neuroblastoma and modern immunotherapy approaches directed towards these markers.

Primary gastric Burkitt lymphoma-induced anaemia: a case report and a literature review

Background.

Primary tumours of the gastrointestinal tract are very uncommon in children. They can present with anaemia caused by gastrointestinal acute or chronic bleeding. One of the most common gastrointestinal tumours is Burkitt lymphoma. This lymphoma is a highly aggressive, rapidly growing B-cell neoplasm, making survival without treatment possible only for a few weeks. For this reason it requires immediate hospitalization and treatment.

Case report.

We report a case of a gastric Burkitt lymphoma in an adolescent girl who presented with anaemia due to gastrointestinal bleeding. She received out-patient care with iron medications orally due to suspected iron-deficiency anaemia but there was no sufficient effect. The patient was referred to Children’s Oncohematology Department with a progression of symptoms (weakness, fatigue, sound in the ears, and nausea) five months after anaemia was diagnosed in the complete blood count. The imaging tests showed a massive solid tumour with bleeding in the stomach. The final diagnosis was a histologically atypical Burkitt lymphoma. Chemotherapy treatment was started according to NHL-BFM 2004 paediatric protocol.

Conclusions.

Non-Hodgin’s lymphoma is the most common malignancy of the gastrointestinal tract in children and about 75% of these tumours are Burkitt lymphomas. They can present with anaemia in the complete blood count due to bleeding. Reticulocyte test and serum ferritin level test help to differentiate pathophysiological origin of anaemia. Combination chemotherapy according to standardized protocols is the best current standard of care and has a very good clinical response without unfavourable risk factors.

Tumor-targeting Salmonella typhimurium A1-R suppressed an imatinib-resistant gastrointestinal stromal tumor with c-kit exon 11 and 17 mutations

Gastrointestinal stromal tumor (GIST) is a refractory disease in need of novel efficacious therapy. The aim of our study was to evaluate the effectiveness of tumor-targeting Salmonella typhimurium A1-R (S. typhimurium A1-R) using on a patient derived orthotopic xenograft (PDOX) model of imatinib-resistant GIST. The GIST was obtained from a patient with regional recurrence, and implanted in the anterior gastric wall of nude mice. The GIST PDOX mice were randomized into 3 groups of 6 mice each when the tumor volume reached 60 mm3: G1, control group; G2, imatinib group (oral administration [p.o.], daily, for 3 weeks); G3, S. typhimurium A1-R group (intravenous [i.v.] injection, weekly, for 3 weeks). All mice from each group were sacrificed on day 22. Relative tumor volume was estimated by laparotomy on day 0 and day 22. Body weight of the mouse was evaluated 2 times per week. We found that S. typhimurium A1-R significantly reduced tumor growth in contrast to the untreated group (P = 0.001). In addition, we found that S. typhimurium A1-R was more effective compared to imatinib (P = 0.013). Furthermore, Imatinib was not significantly effective compared to the control group (P = 0.462). These results indicate that S. typhimurium A1-R may be new effective therapy for imatinib-resistant GIST and therefore a good candidate for clinical development of this disease.

Invasive inflammatory fibroid polyp of the stomach: a case report and literature review

Background

Inflammatory fibroid polyps (IFPs) are rare mesenchymal lesions that affect the gastrointestinal tract. IFPs are generally considered benign, noninvasive lesions; however, we report a case of an invasive gastric IFP. To the best of our knowledge, this is only the second case report of an invasive gastric IFP.

Case presentation

A 62-year-old woman presented with complaints of epigastric pain and vomiting. Computed tomography showed a 27-mm, hyper-enhancing tumor in the prepyloric antrum. Upper endoscopy also showed a submucosal tumor causing subtotal obstruction of the gastric outlet. Because a gastrointestinal stromal tumor was suspected, distal gastrectomy was performed. Histopathological examination revealed spindle cell proliferation in the submucosal layer. The spindle cells had invaded the muscularis propria layer and extended to the subserosal layer. The tumor was finally diagnosed as an IFP based on immunohistochemical findings. No mutations were identified in the platelet-derived growth factor receptor alpha (PDGFRA) gene via molecular genetic analysis.

Discussion and conclusions

After the discovery that IFPs often harbor PDGFRA mutations, these growths have been considered neoplastic lesions rather than reactive lesions. Based on the present case, IFPs might be considered not only neoplastic but also potentially invasive lesions.