Asian Consensus Guidelines for the Diagnosis and Management of Gastrointestinal Stromal Tumor

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.

Clinicopathological Features and Prognosis of Small Gastric Gastrointestinal Stromal Tumors (GISTs)

BACKGROUND

The aim of the present study was to evaluate the safety of endoscopic surgery, the clinicopathological features, and prognoses of small gastric gastrointestinal stromal tumors (GISTs).

METHODS

Small gastric GIST patients (diameter: 0.10-2.00 cm) resected endoscopically in Zhongshan Hospital were retrospectively identified and clinicopathological features and outcomes were collected. The relationship between clinicopathological characteristics and tumor recurrence was analyzed. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal tumor diameter for predicting malignant potential.

RESULTS

All lesions were completely removed by endoscopy and En bloc resection was 98.5%. The most frequent location was the gastric fundus (60.3%) and the average diameter of all lesions was 1.20 cm (range: 0.10-2.00 cm). Mitoses were calculated as more than 5/50 HPF in 44 (6.8%) patients and nuclear atypia was moderate in 243 (37.5%) patients, severe in 1 (0.2%). Necrosis, mucosal infiltration, and vascular infiltration were detected in 8 (1.2%), 5 (0.7%), and 3 (0.5%) patients, respectively. Tumor size was positively correlated with mitotic index (P < 0.001) and nuclear atypia (P < 0.001). After a median follow-up of 54 months, four patients were confirmed local recurrence. ROC curve analysis identified 1.45 cm as the best cut-off value to predict malignant potential (95% CI: 0·694-0·774). Survival analysis showed that patients with tumor diameters larger than 1.45 cm were associated with more local recurrences after resection (P = 0.011).

CONCLUSIONS

Endoscopic surgery is feasible and safe for small gastric GISTs, especially those in favorable locations. Small gastric GISTs bear a good prognosis as a whole but those with diameters larger than 1.45 cm should receive more intensive surveillance or undergo endoscopic surgery.

Endoscopic full-thickness resection using an endoluminal-suturing device: a proof-of-concept study

Background and study aims  Endoscopic full-thickness resection (EFTR) is used to achieve R0 resection in difficult situations and as a way to overcome the limitations of endoscopic submucosal dissection. Multiple techniques have been described but adequate tools are still under evaluation. In this study, we evaluated the safety and feasibility of non-exposed endoscopic full-thickness resection using a novel endoscopic suturing device. Materials and methods  Full-thickness resections of gastric predetermined lesions were performed on five pigs using the Endomina platform. After creating virtual lesion > 20 mm, sutures were placed around it using this triangulation platform. After tightening the knots, the bulging lesion, internalized into the gastric lumen, was cut with a needle knife. Results  R0 resections of large lesions (42 to 60 mm) were achieved in all cases. One perforation occurred and prompted us to improve the procedure by shortening the sutures for more maneuverability and reinforcing the suture line before section. Procedure duration dropped by 50 % between the first case and the fourth case. Histological analysis confirmed successful full-thickness resection of all resected specimens. Conclusion  EFTR using this triangulation platform seems feasible for lesions > 20 mm. Additional possible improvements were identified to simplify the procedure before moving to human trials.

Impact of L-carnitine on imatinib-related muscle cramps in patients with gastrointestinal stromal tumor

Introduction Muscle cramps constitute one of the leading adverse events of imatinib, the standard first-line treatment for advanced gastrointestinal stromal tumor (GIST). This study aims to assess the impact of L-carnitine on relieving cramps in patients with GIST taking imatinib. Materials and methods We reviewed our prospective database for patients with GIST who took L-carnitine (500-mg tablet, 2-3 times daily) for muscle cramps in Asan Medical Center. The assessment tool included severity by the numeric rating scale (NRS), frequency, duration of cramps, and questionnaire for the disturbance in basic activities of daily living (ADL), instrumental ADL (iADL), outdoor activity, or sleeping before and after L-carnitine treatment. Results We examined 42 patients [median age: 60 (range: 17-81) years; males, 52.4%] who received L-carnitine for cramps on NRS ≥ 4 intensity during 2016-2017. In 83.3% of patients (n = 35), the NRS score declined to <4 points, with 8 patients (19.0%) experiencing complete disappearance of symptoms [median response time: 10 (range: 2-30) days]. Moreover, the median duration of each episode and frequency decreased from 5 to 2 min and from 30 to 3 times per month (P < 0.001), respectively. We observed substantial improvement in all quality-of-life aspects after L-carnitine (ADL, 73.2%-14.6%; iADL, 73.2%-17.1%; sleeping, 78.0%-22.0%; outdoor activity, 68.3%-17.1%; P < 0.001). ConclusionL-carnitine could effectively relieve imatinib-related muscle cramps in patients with GIST. Accordingly, a randomized phase 3 study is currently ongoing (NCT03426722).

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.

Endoscopic full-thickness resection for a gastrointestinal stromal tumor in a liver transplant recipient: A case report

RATIONALE

With the development of endoscopic technique and the improvement of available accessories, endoscopic therapy became to play an important role in the management of gastrointestinal submucosal tumors (SMTs).

PATIENTS CONCERNS

A gastric SMT which was suspected to be gastrointestinal stroma tumor (GIST) was diagnosed in a liver transplant recipient who received transplanted operation 11 months ago.

DIAGNOSIS

gastric SMT, post-liver transplantation INTERVENTIONS:: Endoscopic full-thickness resection (EFR) was preformed to remove the tumor. The operation time was 50 minutes and oral immunosuppressant drug was not interrupted in the postoperative period.

OUTCOMES

The clinical course was uneventful and slightly elevated liver enzyme was observed on the fourth day after operation. The pathological diagnosis was GIST with complete capsule.

LESSONS

Our successful experience showed that EFR is a feasible, safe and efficacious treatment for small (<2 cm) gastric GIST in liver transplant recipients, providing the advantages of little damage, short operative time, stable graft function, without compromising postoperative outcomes.

Gastric sub-epithelial tumors: identification of gastrointestinal stromal tumors using CT with a practical scoring method

OBJECTIVES

To determine CT features that can identify gastrointestinal stromal tumors (GISTs) among gastric sub-epithelial tumors (SETs) and to explore a practical scoring method.

METHODS

Sixty-four patients with gastric SETs (51 GISTs and 13 non-GISTs) from hospital I were included for primary analyses, and 92 (67 GISTs and 25 non-GISTs) from hospital II constituted a validation cohort. Pre-operative CT images were reviewed for imaging features: lesion location, growth pattern, lesion margin, enhancement pattern, dynamic pattern, attenuation at each phasic images and presence of necrosis, superficial ulcer, calcification, and peri-lesion enlarged lymph node (LN). Clinical and CT features were compared between the two groups (GISTs versus non-GISTs) and a GIST-risk scoring method was developed; then, its performance for identifying GISTs was tested in the validation cohort.

RESULTS

Seven clinical and CT features were significantly suggestive of GISTs rather than non-GISTs: older age (> 49 years), non-cardial location, irregular margin, lower attenuation on unenhanced images (≤ 43 HU), heterogeneous enhancement, necrosis, and absence of enlarged LN (p < 0.05). At validation step, the established scoring method with cut-off score dichotomized into ≥ 4 versus < 4 for identifying GISTs revealed an AUC of 0.97 with an accuracy of 92%, a sensitivity of 100% and a negative predictive value (NPV) of 100%.

CONCLUSIONS

Gastric GISTs have special CT and clinical features that differ from non-GISTs. With a simple and practical scoring method based on the significant features, GISTs can be accurately differentiated from non-GISTs.

Primary hepatic gastrointestinal stromal tumor with right adrenal gland invasion: A case report and systematic literature review

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors that mainly occur in the gastrointestinal tract. The GISTs that are sporadically reported in extra-gastrointestinal regions are named as extra-gastrointestinal stromal tumors (EGISTs). However, the primary EGISTs that originate from the liver are rare.

PATIENT CONCERNS

A 64-year-old female presenting with right upper abdominal pain and thirsty for more than 20 days.

DIAGNOSIS

A diagnosis of a 15 × 14 × 7 cm liver mass located in the posterior right lobe of liver and spread to the right adrenal gland was confirmed. Pathological results showed that the tumor was mainly composed of epithelial cells and tested positive for CD117 and SDHB (succinate dehydrogenase complex iron sulfur subunit B). The gene mutational analyses for c-Kit and platelet-derived growth factor receptor alpha exons revealed negative results. Fluorescence in situ hybridization of murine double minute 2 produced negative fluorescence results which distinguished it from dedifferentiated liposarcomas. The postoperative gastroduodenal and colorectal endoscopy did not find any neoplastic lesions. To this end, the diagnosis of primary hepatic EGIST of wild type nature was confirmed.

INTERVENTIONS

The patient received right hepatectomy and adrenalectomy, no postoperative chemotherapy was administered.

OUTCOMES

The patient died 11 months after surgery due to tumor metastasis.

CONCLUSION

Primary hepatic EGIST is a rare and complicated disease of liver, a multidisciplinary team is necessary in diagnosis and treatment of primary hepatic EGIST.

Phase II Trial of Continuous Regorafenib Dosing in Patients with Gastrointestinal Stromal Tumors After Failure of Imatinib and Sunitinib

BACKGROUND

Regorafenib at the standard intermittent dosing schedule proved effective in the GRID trial for refractory gastrointestinal stromal tumors (GISTs). However, this dosing schedule requires frequent dose reduction, and the progression of GISTs or tumor-related symptoms during the off-treatment period has also been noted in some patients. Therefore, we conducted this phase II trial to evaluate the efficacy and safety of regorafenib at a lower dose on a continuous dosing schedule.

METHODS

Patients with measurable, metastatic, or recurrent GISTs who failed to respond to both imatinib and sunitinib were eligible for this study. Regorafenib 100 mg p.o. daily was administered continuously. The primary endpoint was disease control rate (DCR: complete response plus partial response [PR] plus stable disease [SD]) lasting for at least 12 weeks using RECIST version 1.1.

RESULTS

The best response was PR in 2 (8%), SD in 16 (64%), and progressive disease in 6 (24%) patients. DCR lasting for at least 12 weeks was 64% (16 of 25). The median progression-free survival was 7.3 months (95% confidence interval, 5.9-8.6), and the 1-year survival rate was 64.5%. Ten patients (40%) experienced grade 3-4 toxicities, including hand-foot skin reaction (n = 4, 16%) and elevation of alanine aminotransferase (n = 2, 8%). Only six patients (24%) needed dose modification with a relative dose intensity of 95.0% for eight cycles in all patients.

CONCLUSION

Regorafenib at a lower dose on a continuous schedule might be an alternative treatment in patients with GISTs after failure of imatinib and sunitinib. Clinical trial identification number. NCT02889328 IMPLICATIONS FOR PRACTICE: Regorafenib at the standard intermittent dosing schedule proved effective in the GRID trial for refractory gastrointestinal stromal tumors (GISTs). However, this dosing schedule requires frequent dose reduction, and the progression of GISTs or tumor-related symptoms during the off-treatment period has been noted in some patients. This study was to evaluate the efficacy and safety of regorafenib at a lower dose on a continuous dosing schedule. With good efficacy and acceptable safety profiles, regorafenib at a lower, continuously administered dose might be an alternative treatment in patients with GISTs after imatinib and sunitinib. Rechallenge of regorafenib may slow the disease progression.

Intra-abdominal desmoid tumors mimicking gastrointestinal stromal tumors - 8 cases: A case report

BACKGROUND

Intra-abdominal desmoid tumors (DTs) can mimic recurrence or progression of gastrointestinal stromal tumors (GISTs). Differential diagnosis is important to avoid unnecessary or inappropriate treatment.

CASE SUMMARY

All 8 patients experienced surgical resection of GIST, and median time to diagnosis of DT was 1.8 years after surgical resection. All sites of DT were in the peritoneum around the surgical sites of GIST. The following clinical suspicion coupled with radiological findings contributed to the suspicion of intra-abdominal DTs: (1) Occurrence of a new single lesion in the peritoneum around the surgical sites of GIST; (2) uncontrolled lesion with imatinib while other lesions being controlled with imatinib; (3) well-defined ovoid shaped lesion with delayed or mild enhancement and absence of necrosis, hemorrhage, and cystic change on computed tomography; and (4) a lesion showing mild or no hypermetabolic activity on 18fluorodeoxyglucose-positron emission tomography, contrary to initially hyperactive lesion of GIST. All DTs were surgically removed except for one unresectable DT and only one DT recurred at another site of peritoneum, which was also surgically removed.

CONCLUSION

Intra-abdominal DT should be a differential diagnosis for a new single lesion in patients with GIST.

Value of contrast-enhanced harmonic endoscopic ultrasonography in differentiating between gastrointestinal stromal tumors: A meta-analysis

OBJECTIVE

Contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) is a valuable device to diagnose and determine the malignant potential of gastrointestinal stromal tumors (GIST) as early as possible when making clinical therapeutic decisions. This study aimed to estimate the ability of CH-EUS to discriminate between GIST and benign submucosal lesions (SML) and to predict their malignant potential.

METHODS

PubMed, MEDLINE, EMBASE, the Web of Science, and Cochrane Central Register of Controlled Trials databases were screened. Using the data provided in the literatures, 2 × 2 tables were constructed to obtain the pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio. A receiver operating characteristic (ROC) curve was generated and the area under the ROC curve (AUROC) was calculated.

RESULTS

Four studies with a total of 187 patients were identified to evaluate the value of CH-EUS in discriminating between GIST and benign SML. The pooled sensitivity, specificity, and AUROC were 89% (95% CI 0.82-0.93), 82% (95% CI 0.66-0.92), and 0.89, respectively. Five studies including 143 patients were analyzed to assess the accuracy of CH-EUS in determining the malignant potential of GIST. The pooled sensitivity, specificity, and AUROC curve of CH-EUS were 96% (95% CI 0.90-0.99), 53% (95% CI 0.40-0.66), and 0.92, respectively.

CONCLUSIONS

CH-EUS is a safe, noninvasive method that can distinguish between GIST and benign subepithelial lesions and to predict their malignant potential to a certain extent. Large-scale, multicenter prospective studies are needed in the future.

[Comparative treatment analysis of upper gastroenterology submucosal tumors originating from muscularis propria layer: submucosal tunneling endoscopic resection versus endoscopic submucosal excavation]

OBJECTIVE

To evaluate the efficacy and safety of submucosal tunneling endoscopic resection (STER) and endoscopic submucosal excavation (ESE) for upper gastroenterology submucosal tumors (SMT) originating from the muscularis propria (MP) layer.

METHODS

Clinicopathological and endoscopic data of 42 cases with upper gastroenterology tumors originating from the MP layer who were treated with STER (n=28) or ESE (n=14) between April 2013 and December 2016 in Peking University Third Hospital were retrospectively analyzed. The treatment and complications of the two groups were compared.

RESULTS

In the study, 42 cases were all resected by therapeutic endoscopy successfully．There was no significant difference (STER vs. ESE) in gender, age, mean tumor size [1.5 (1.0-6.0) cm vs. 1.3 (0.5-2.0) cm, P=0.056]. STER was superior to ESE with reduced sutured time [3.5 (1.0-11.0) min vs. 8.0 (2.0-33.0) min, P=0.006], but more resection time [46.5 (11.0-163.0) min vs.19.5 (6.0-56.0) min, P=0.007]. There was statistical difference between the two groups in resection time or sutured time, but no significant difference (STER vs. ESE) in total operative time [52.0 (14.0-167.0) min vs. 31.5 (10.0-88.0) min, P=0.080]. En bloc resection rates (92.9% vs. 85.7%), hospital stay duration and complications (10.7 vs. 0.0) were similar in the STER and ESE groups. One case developed mediastinal emphysema and 2 pneumonia after operation in STER group, and all of them recovered uneventfully after conservative treatments; There were no complications in the ESE group. After operation, 28 cases of leiomyoma and 14 cases of stromal tumor were diagnosed by routine pathological and immunohistochemical staining. Among them, 6 cases of stromal tumors in group STER were all extremely low risk, 4 cases of stromal tumors in group ESE were extremely low risk, 4 cases of stromal tumors in group ESE were medium risk (the size of the lesion was about 1.0-2.0 cm, and mitotic figures counted (6-8)/50 high power field). The median follow-up time of all the patients was 46.5 (24-60) months, and the shortest follow-up time for medium risk stromal tumors was 32 months. No residual tumor, recurrence and implantation in the tunnel were observed.

CONCLUSION

STER or ESE can be used as an effective and safe option for treatment of submucosal tumors originating from the muscularis propria of the upper digestive tract. Compared with STER, ESE had shorter resection time but longer wound closure time. There was no significant difference in total operation time.

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.

Long-term survival outcome with tyrosine kinase inhibitors and surgical intervention in patients with metastatic or recurrent gastrointestinal stromal tumors: A 14-year, single-center experience

The long‐term effects of tyrosine kinase inhibitors (TKIs), including imatinib, and surgical intervention on advanced gastrointestinal stromal tumor (GIST) were evaluated. All 379 patients had metastatic or recurrent GIST and started 400 mg/d imatinib at the Asan Medical Center in periods 1 and 2 [2001‐2007 (33.2%) and 2008‐2014 (66.8%), respectively]. Men constituted 60.4%; median patient age and tumor size at the initiation of imatinib were 58.6 (14.6‐85.5) years and 51 (0‐324) mm, respectively, without differences between periods except for older age and less preimatinib surgery in period 2. Response and disease control rates with imatinib in measurable GIST were 63.1% and 94.3%, respectively, without differences between periods. More patients in period 2 underwent surgical resection for TKI‐responsive diseases within the first 2 years (24.9%, P = 0.006). With a median follow‐up of 6.1 years (2.5‐16.0) in survivors, median progression‐free survival (PFS) was 5.4 years [95% confidence interval (CI), 4.0‐6.9]. Subsequent sunitinib (P = 0.066) and regorafenib (P = 0.003) were more commonly administered in period 2. Median overall survival (OS) was 8.8 years (95% CI, 7.8‐9.7). PFS with imatinib (P = 0.002) and OS (P = 0.019) were significantly longer in period 2. Young age, smaller tumor size at the initiation of imatinib, KIT exon 11 mutation, surgical intervention, and period 2 were favorable factors for PFS and OS. Patients with advanced GIST showed better prognosis with the optimal use of imatinib, along with active surgical intervention and more common use of subsequent TKIs in period 2.

Per oral endoscopic tumor (POET) resection for treatment of upper gastrointestinal subepithelial tumors

BACKGROUND

Endoscopic submucosal tunneling has evolved to allow endoscopic resection of subepithelial tumors of gastrointestinal tract without full-thickness perforation. This study aimed to investigate safety and efficacy of submucosal tunnel resection for these tumors.

METHOD

Patients with subepithelial tumors (SET) located in esophagus, gastric cardia, lesser curvature, and antrum were recruited. The size of tumor was limited to < 40 mm. The procedures were performed under general anesthesia. A mucosal entrance was created 2 cm proximal to the SET after submucosal injection. Submucosal tunnel was then extended and the tumor was dissected and mobilized with intact overlying mucosa. After complete dissection, the tumors would be retrieved per orally and mucosal entrance closed by endoclips.

RESULTS

From June 2012 to December 2016, 51 patients with subepithelial tumors received POET. 39 patients had SET in stomach, 11 located in esophagus, and 1 in duodenum. The mean operative time was 90.46 ± 46.49 min, while the mean size of the tumors was 20.71 ± 14.05 mm. The POET was converted to endoscopic full-thickness resection (EFTR) in three patients with gastric subepithelial tumors located at greater curvature. The overall complication rate was 4.0%, and there was no bleeding, mucosal dehiscence, or leakage. The time to resume diet was 1.7 days, while the average hospital stay was 3.2 ± 1.0 days. The mean follow-up period was 19 ± 16 months, and only 1 patient developed recurrence of leiomyoma.

CONCLUSION

Per oral endoscopic tumor resection is safe and effective treatment for esophageal and gastric SET located at cardia, lesser curvature, and antrum. Currently, POET for treatment of upper GI SET is limited by the size and location of the tumor.

A Novel Pathological Prognostic Score (PPS) to Identify "Very High-Risk" Patients: a Multicenter Retrospective Analysis of 506 Patients with High Risk Gastrointestinal Stromal Tumor (GIST)

BACKGROUND

To determine the better risk stratification based on surgical pathology and to assess the clinical outcomes after curative resection with a new scoring system in high risk gastrointestinal stromal tumor (GIST) patients.

METHODS

We retrospectively evaluated 506 high-risk GIST patients who underwent curative resection as initial treatment at four centers from 2001 to 2015.

RESULTS

Multivariate analysis revealed that only Ki-67 labeling index (LI) and mitotic index were independent prognostic factors of overall survival (OS). For the two tumor-related pathological factors, Ki-67 LI > 7% and mitotic index ≥ 7/50 high power fields were allocated 1 point each. The total score was defined as the Pathological Prognostic Score (PPS). When Ki-67 LI and mitotic index were replaced by PPS, a multivariate analysis still identified PPS as an independent predictor of OS (HR 2.719; 95% CI 1.309-5.650; P = 0.007). Patients with a PPS of 0, 1, or 2 had a 5-year survival of 91.8, 79.8, and 51.0%, respectively (P = 0.001). Furthermore, an elevated PPS (PPS = 2) was associated with larger tumor size, non-stomach tumor, and open resection (all P < 0.05).

CONCLUSION

The PPS independently predicted postoperative survival in high-risk GIST, and it might facilitate the selection of appropriate treatment strategy for these patients.

Gastric ectopic pancreas mimicking a gastrointestinal stromal tumour: A case report

•

The diagnosis and management of gastric submucosal tumours are fraught with difficulty and uncertainty.

•

After a thorough work-up with gastroscopy and endoscopic ultrasonography, a gastrointestinal stromal tumour of the antrum was diagnosed.

•

Laparoscopic excision was performed – histopathologically, an ectopic pancreas was diagnosed.

•

Despite an adequate work-up, surgery was performed for an essentially benign lesion.

Introduction

The diagnosis and management of upper gastrointestinal tract submucosal tumours can be challenging due to the difficulties with adequate pre-operative characterization and tissue sampling.

Presentation of the case

A 61-year-old female patient underwent esophagogastroduodenoscopy because of epigastric pain and episodic vomiting. A submucosal tumour was found along the greater curvature in the antrum. On endoscopic ultrasound, the mass was suspected to be a gastrointestinal stromal tumour. The patient was referred for laparoscopic excision. The final histopathological examination confirmed an ectopic pancreas, not a gastrointestinal stromal tumour as thought preoperatively.

Discussion

Despite an adequate pre-operative diagnostic workup with endoscopic ultrasonography, the lesion was misdiagnosed as a gastrointestinal stromal tumour and surgery was performed to excise an ectopic pancreas, essentially a benign lesion.

Conclusion

The case highlights the absence of firm diagnostic criteria to differentiate submucosal gastric lesions.

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.

Robotic Gastrotomy With Intracorporeal Suture for Patients With Gastric Gastrointestinal Stromal Tumors Located at Cardia and Subcardiac Region

PURPOSE

Few studies of robotic gastric gastrointestinal stromal tumors (GISTs) resection have been conducted. This study was aimed to evaluate the robotic gastrotomy with intracorporeal suture for patients with GISTs located at cardia and subcardiac region.

MATERIALS AND METHODS

From January 2014 to August 2016, 11 patients with GISTs located at cardia and subcardiac region underwent robotic gastrotomy with intracorporeal suture. Data of these patients were collected.

RESULTS

The mean operative time was 82.7 minutes and the mean blood loss was 30.0 mL. No complication was reported. The postoperative length of stay was 3.3 days. On postoperative day 14, inflammation recovered to preoperative level. On postoperative month 6, the nutritional status was similar to that before the surgery. After 25.5 months follow-up, all patients survived with no recurrence or metastasis.

CONCLUSIONS

Robotic gastrotomy with intracorporeal suture for patients with GISTs located at cardia and subcardiac region is safe and feasible.

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.

Tumor rupture of gastric gastrointestinal stromal tumors during endoscopic resection: a risk factor for peritoneal metastasis?

BACKGROUND AND STUDY AIMS

 Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal tract. Up to the present time, complete surgical excision has been the standard treatment for primary GISTs greater than 2 cm. It is well known that tumor rupture during surgery is an independent risk factor for peritoneal metastasis; however, it is not known whether the risk of peritoneal metastasis increases in cases where the tumor is ruptured during endoscopic resection.

PATIENTS AND METHODS

 A total of 195 patients treated for GIST between January 2014 and December 2016 in our hospital were enrolled in this study. They were divided into two groups according to whether the tumor was ruptured during endoscopic resection. The rate of peritoneal metastasis in patients in the two groups who also suffered perforation was investigated from the follow-up results.

RESULTS

 Approximately 55.4 % of all patients were female and the average age of the study group was 59.0 ± 10.3 years. Of the 195 patients, the tumors in 27 were ruptured and the remaining 168 patients underwent en bloc resection. There was no statistically significant difference in gender or age between the two groups. The median tumor size (maximum diameter) in all patients was 1.5 cm (0.3 - 5.0 cm): 2.5 cm (0.8 - 5.0 cm) and 1.4 cm (0.3 - 4.0 cm) in the tumor rupture group and en bloc resection group, respectively ( P  < 0.001). Most of the tumors were located in the gastric fundus. At a median follow-up of 18.7 ± 10.2 months, neither tumor recurrence (liver metastasis, peritoneal metastasis, local recurrence) nor mortality related to GISTs were detected.

CONCLUSIONS

 Tumor rupture during endoscopic resection of gastric GISTs may not be a risk factor for peritoneal metastasis.

Inhibition of stromal-interacting molecule 1-mediated store-operated Ca2+ entry as a novel strategy for the treatment of acquired imatinib-resistant gastrointestinal stromal tumors

Imatinib has revolutionized the treatment of gastrointestinal stromal tumors (GIST); however, primary and secondary resistance to imatinib is still a major cause of treatment failure. Multiple mechanisms are involved in this progression. In the present study, we reported a novel mechanism for the acquired resistance to imatinib, which was induced by enhanced Ca²⁺ influx via stromal‐interacting molecule 1 (STIM1)‐mediated store‐operated Ca²⁺ entry (SOCE). We found that the STIM1 expression level was related to the acquired resistance to imatinib in our studied cohort. The function of STIM1 in imatinib‐resistant GIST cells was also confirmed both in vivo and in vitro. The results showed that STIM1 overexpression contributed to SOCE and drug response in imatinib‐sensitive GIST cells. Blockage of SOCE by STIM1 knockdown suppressed the proliferation of imatinib‐resistant GIST cell lines and xenografts. In addition, STIM1‐mediated SOCE exerted an antiapoptotic effect via the MEK/ERK pathway. The results from this study provide a basis for further research into potential novel therapeutic strategies in acquired imatinib‐resistant GIST.

Using the recurrence risk score by Joensuu to assess patients with gastrointestinal stromal tumor treated with adjuvant imatinib: A retrospective cohort study

In 2014, Joensuu and colleagues devised the first recurrence risk score (RRS) to identify the risk factors for gastrointestinal stromal tumor (GIST) recurrence. However, there are scarce data available on RRS effectiveness and efficiency. Therefore, we retrospectively analyzed clinical data to validate Joensuu's RRS in patients treated with adjuvant imatinib.In this retrospective cohort study, data were collected from patients with GIST who were treated with adjuvant imatinib between December 2005 and May 2017 in the West China Hospital. The study consisted of 137 patients, after application of inclusion and exclusion criteria. Recurrence-free survival (RFS) was the primary end point.The RRSs for 137 patients were divided into 3 groups: low (n = 46), medium (n = 48), and high (n = 43). The RFSs of the 3 groups were significantly different (P < .001). In patients who received adjuvant imatinib for <36 months, the RFS difference was also significant (P < .001), and the result was similar in patients treated with adjuvant imatinib for ≥36 months (P = .03). The area under the curve of the RRS was 0.84 ([95% confidence interval] 0.76-0.92, P < .001), suggesting that the RRS method could accurately assess recurrence risks for patients with GIST who were treated with adjuvant imatinib.It is appropriate to apply the RRS method to assess recurrence risks for patients with GIST who were treated with adjuvant imatinib. A longer adjuvant imatinib duration is recommended for high-risk patients with GIST. It is also important to identify a more effective treatment for patients who are resistant to imatinib.

Asian consensus guidelines for gastrointestinal stromal tumor: what is the same and what is different from global guidelines

There are some disparities between the clinical practice and profiles of cancer in Asia and those in Europe & North America. In Asia, surgical oncologists still have a major role in the multidisciplinary therapy of gastrointestinal stromal tumor (GIST), whereas medical oncologists hold this status in the West. Although the incidence of clinical GIST is considered similar between the two areas, small gastric GISTs are more frequently treated by surgery in East Asia compared with Europe & North America. The diagnosis and treatment of small submucosal tumors (SMTs), including GIST, is important in Asian clinical practice guidelines for GIST. Most items of Asian and Western GIST guidelines are very similar. There are slight differences between the two guidelines in the degree of recommendation, which may come from disparities of clinical practice and available medicines. Importantly, most clinical evidence in the GIST guidelines has been established by clinical trials conducted in Western countries, and the number of clinical trials is still limited in Asia, suggesting that Asian GIST patients may have limited access to investigational drugs after standard therapy. Finally, both Asian and Western GIST guidelines are well-harmonized in some parts, and their contents may reflect the medical circumstances of each region.

Prognostic factors of primary gastrointestinal stromal tumors: a cohort study based on high-volume centers

Objective

We aimed to evaluate the clinicopathologic characteristics, immunohistochemical expression and prognostic factors of patients with primary gastrointestinal stromal tumors (GISTs).

Methods

Data from 2,570 consecutive GIST patients from four medical centers in China (January 2001-December 2015) were reviewed. Survival curves were constructed by the Kaplan-Meier method, and Cox regression models were used to identify independent prognostic factors.

Results

Of the included patients, 1,375 (53.5%) were male, and the patient age range was 18 to 95 (median, 58) years. The tumors were mostly found in the stomach (64.5%), small intestine (25.1%) and colorectal region (5.1%). At the time of diagnosis, the median tumor size was 4.0 (range: 0.1-55.0) cm, and the median mitotic index per 50 high power fields (HPFs) was 3 (range: 0-254). Of the 2,168 resected patients, 2,009 (92.7%) received curative resection. According to the modified National Institutes of Health (NIH) classification, 21.9%, 28.9%, 14.1% and 35.1% were very low-, low-, intermediate- and high-risk tumors, respectively. The rate of positivity was 96.4% for c-Kit, 87.1% for CD34, 96.9% for delay of germination 1 (DOG-1), 8.0% for S-100, 31.0% for smooth muscle actin (SMA) and 5.1% for desmin. However, the prognostic value of each was limited. Multivariate analysis showed that age, tumor size, mitotic index, tumor site, occurrence of curative resection and postoperative imatinib were independent prognostic factors. Furthermore, we found that high-risk patients benefited significantly from postoperative imatinib (P<0.001), whereas intermediate-risk patients did not (P=0.954).

Conclusions

Age, tumor size, mitotic index, tumor site, occurrence of curative resection and postoperative imatinib were independent prognostic factors in patients with GISTs. Moreover, determining whether intermediate-risk patients can benefit from adjuvant imatinib would be of considerable interest in future studies.

Endoscopic resection of gastric gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal tract, and about 60% of them are found in the stomach. With the widespread application of endoscopy and endoscopic ultrasonography (EUS), more and more gastric GISTs are being found in an early stage (with a relative small diameter and no metastasis), giving the chance of complete resection. Endoscopic resection such as endoscopic band ligation (EBL), endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), endoscopic full-thickness resection (EFTR) and submucosal tunneling endoscopic resection (STER), is a minimally invasive method compared with the conventional surgical approaches (open or laparoscopic), and has been demonstrated to be safe and effective for treating gastric GISTs. This review summarizes the recent advances on endoscopic resection of gastric GISTs, aiming to provide a rational management strategy for gastric GISTs.

A Diagnostic Surprise For A Right Iliac Fossa Mass - A Perforated Ileal Gastrointestinal Stromal Tumour

Gastrointestinal Stromal Tumours (GISTs) are tumours of the gut found mostly in stomach and small intestine. The complications are Gastrointestinal (GI) bleeding, obstruction, pain and rarely perforation. We are reporting an abnormal presentation of GIST masquerading as an acute abdomen with Right Iliac Fossa (RIF) mass in 60-year-old lady. Contrast Enhanced Computed Tomography (CECT) of abdomen revealed a peripherally enhancing encapsulated abscess in RIF in close contact with base of caecum and adjacent peritonitis suggesting caecal perforation. On laparotomy, a gangrenous perforated ileal GIST was identified along the antimesenteric border of ileum. Pathological examination confirmed the tumour to be a GIST of spindle cell type, further reiterated by immunohistochemistry. Our case report emphasizes, GIST as a rare and unusual differential diagnosis of RIF mass, and to have high degree of clinical suspicion when a similar situation is encountered in an emergency scenario, keeping in mind the poor outcome due to delay in appropriate management of the disease.

Adjuvant imatinib for patients with high-risk gastrointestinal stromal tumors: a retrospective cohort study

The duration of adjuvant imatinib for high-risk patients with gastrointestinal stromal tumors (GISTs) is still controversial. Therefore, we retrospectively analyzed the data of high-risk patients with GISTs to investigate the appropriate duration. All 185 patients were divided into 4 groups: <1 year (Group A), 1–2 years (Group B), 2–3 years (Group C) and >3 years (Group D). The mean recurrence-free survival (RFS) in Groups A, B, and C were 44.3, 62.1, and 86.8 months, respectively (P < 0.001); the mean overall survival (OS) in Groups A, B and C was 75.2, 88.1, and 94.7 months, respectively (P = 0.009). The 5-year RFS in Groups A, B, C, and D was 15%, 26%, 83%, and 100%, respectively (P < 0.001); and the 5-year OS was 64%, 88%, 88%, and 100%, respectively (P < 0.001). The greatest impact on unfavorable outcomes was the tumor mitotic rate (HR, 2.01, 95% CI, 1.38–2.94; P < 0.001). Duration of adjuvant imatinib was the only favorable factor (HR, −0.95, 95% CI, 0.93–0.97; P < 0.001). For high-risk patients with high tumor size or mitotic rate, or non-gastric GISTs, we recommend that more than 3 years of adjuvant imatinib is feasible.

Laparoscopic total gastrectomy for a giant gastrointestinal stromal tumor (GIST) with acute massive gastrointestinal bleeding: a case report

Gastrointestinal stromal tumors (GISTs) include 80% of gastrointestinal mesenchymal tumors that originate from interstitial Cajal cells and include 0.1–3% of GI malignancies, and the stomach is the most commonly involved organ. The only potentially curative treatment is surgical resection with clear margins. Although laparoscopic resection of small GISTs is a standard treatment, there is controversy about laparoscopic surgical resection for large and giant GISTs. A 52-year-old woman, a known case of large GIST of the stomach that was under neoadjuvant imatinib therapy, was admitted to the emergency department due to acute massive gastrointestinal bleeding (GIB). The patient underwent laparoscopic total gastrectomy and received adjuvant imatinib after surgery. Laparoscopic resection is a safe and feasible method in large and giant GISTs with oncologic and long-term outcomes comparable to open surgery, and with better short-term outcomes.

Evidence mapping based on systematic reviews of therapeutic interventions for gastrointestinal stromal tumors (GIST)

Background

Gastrointestinal Stromal Tumours (GISTs) are the most common mesenchymal tumours. Currently, different pharmacological and surgical options are used to treat localised and metastatic GISTs, although this research field is broad and the body of evidence is scattered and expanding. Our objectives are to identify, describe and organise the current available evidence for GIST through an evidence mapping approach.

Methods

We followed the methodology of Global Evidence Mapping (GEM). We searched Pubmed, EMBASE, The Cochrane Library and Epistemonikos in order to identify systematic reviews (SRs) with or without meta-analyses published between 1990 and March 2016. Two authors assessed eligibility and extracted data. Methodological quality of the included systematic reviews was assessed using AMSTAR. We organised the results according to identified PICO questions and presented the evidence map in tables and a bubble plot.

Results

A total of 17 SRs met eligibility criteria. These reviews included 66 individual studies, of which three quarters were either observational or uncontrolled clinical trials. Overall, the quality of the included SRs was moderate or high. In total, we extracted 14 PICO questions from them and the corresponding results mostly favoured the intervention arm.

Conclusions

The most common type of study used to evaluate therapeutic interventions in GIST sarcomas has been non-experimental studies. However, the majority of the interventions are reported as beneficial or probably beneficial by the respective authors of SRs. The evidence mapping is a useful and reliable methodology to identify and present the existing evidence about therapeutic interventions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-017-0402-9) contains supplementary material, which is available to authorized users.

Current research and treatment for gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and have gained considerable research and treatment interest, especially in the last two decades. GISTs are driven by mutations commonly found in the KIT gene and less commonly in the platelet-derived growth factor receptor alpha gene, BRAF gene and succinate dehydrogenase gene. GISTs behave in a spectrum of malignant potential, and both the tumor size and mitotic index are the most commonly used prognostic criteria. Whilst surgical resection can offer the best cure, targeted therapy in the form of tyrosine kinase inhibitors (TKIs) has revolutionized the management options. As the first-line TKI, imatinib offers treatment for advanced and metastatic GISTs, adjuvant therapy in high-risk GISTs and as a neoadjuvant agent to downsize large tumors prior to resection. The emergence of drug resistance has altered some treatment options, including prolonging the first-line TKI from 1 to 3 years, increasing the dose of TKI or switching to second-line TKI. Other newer TKIs, such as sunitinib and regorafenib, may offer some treatment options for imatinib-resistant GISTs. New molecular targeted therapies are being evaluated, such as inhibitors of BRAF, heat shock protein 90, glutamine and mitogen-activated protein kinase signaling, as well as inhibitors of apoptosis proteins antagonist and even immunotherapy. This editorial review summarizes the recent research trials and potential treatment targets that may influence our future patient-specific management of GISTs. The current guidelines in GIST management from Europe, North America and Asia are highlighted.

Laparoscopic management of gastric gastrointestinal stromal tumors: A retrospective 10-year single-center experience

AIM

To determine the feasibility, safety, and oncological outcome of laparoscopic resection of gastric gastrointestinal stromal tumors (GISTs) based on favorable or unfavorable location.

METHODS

Our hospital database included 207 patients who underwent laparoscopic removal of gastric GISTs from January 2004 to September 2015. Patient demographics, clinical presentation, surgery, histopathology, postoperative course, and oncological outcomes were reviewed and analyzed.

RESULTS

Gastric GIST in favorable locations was present in 81/207 (39.1%) cases, and in unfavorable locations in 126/207 (60.9%) cases. Overall mean tumor size was 3.28 ± 1.82 cm. No conversions occurred, and complete R0 resection was achieved in 207 (100%) cases. There were three incidences of iatrogenic tumor rupture. The feasibility and safety of laparoscopic surgery were comparable in both groups with no statistical difference between unfavorable and favorable location groups, respectively: for operative time: 83.86 ± 44.41 vs 80.77 ± 36.46 min, P = 0.627; conversion rate: 0% vs 0%; estimated blood loss: 27.74 ± 45.2 vs 29.59 ± 41.18 mL, P = 0.780; tumor rupture during surgery: 0.90% vs 2.82%, P = 0.322; or postoperative complications: 3.74% vs 7.04%, P = 0.325. The follow-up period recurrence rate was 1.89% with no significant differences between the two groups (3.03% vs 0%, P = 0.447). Overall 5-year survival rate was 98.76% and survival rates were similar between the two groups: 98.99% vs 98.39%, P = 0.623 (unfavorable vs favorable, respectively).

CONCLUSION

The laparoscopic approach for gastric GISTs is safe and feasible with well-accepted oncological surgical outcomes. Strategies for laparoscopic resection should be selected according to the location and size of the tumor. Laparoscopic treatment of gastric GISTs in unfavorable locations should not be restricted in gastrointestinal centers.

Percutaneous endoscopic intragastric surgery: an organ preserving approach to submucosal tumors at esophagogastric junction

As an organ preserving option in the treatment of submucosal tumor found at the esophagogastric junction (EGJ), percutaneous endoscopic intragastric surgery (PEIGS) plays an important role, while it is not commonly performed and there have been very few reports on this unique operation. The current authors have been performing PEIGS since 1993 and have reported on its short- and long-term outcomes from one of the world largest series. Herein its confusing terminology is discussed and techniques of three different types of PEIGS (original PEIGS, single incision PEIGS, and needlescopic PEIGS) are precisely described. Although reports on clinical outcomes of PEIGS have been rarely published, both short-term and long-term outcomes seem acceptable, as far as we review our own experiences and the past literatures. PEIGS needs to be accessed by the data from larger series or RCT to be further justified and spread for the patients with submucosal tumors at EGJ to salvage their stomach.

Drill needle aspiration biopsy for submucosal tumors in an experimental study

BACKGROUND AND AIMS

EUS-guided FNA biopsy has been widely performed to aid in the diagnosis of submucosal tumors (SMTs). However, in cases of small tumors, the diagnostic yield of EUS-FNA is poor. Therefore, it is necessary to develop a new needle for the diagnosis. We developed a device with a new mechanism that we refer to as a drill needle aspiration biopsy (DNAB). The aim of this study was to evaluate the use of DNAB in resected gastric SMT specimens.

METHODS

A drill needle with a sharp tip and wide ditch was inserted into a catheter for angiography. Continuous suction is enabled through the catheter at the tip. DNAB was performed with one pass and one stroke in 13 gastric SMTs resected by operation. Similarly, FNA was performed by one pass and ten strokes. These gastric tumors included nine diagnosed gastrointestinal stromal tumors and four undiagnosed SMTs by preoperative examinations. The tissue quantity between DNAB and FNA was macroscopically and microscopically examined.

RESULTS

All 13 drill biopsy specimens were obtained. Additionally, all 13 gastric SMTs, including 4 undiagnosed tumors, could be diagnosed by DNAB. The quantity of each specimen obtained by DNAB was macroscopically and microscopically much greater than that by FNA. In particular, for tumors <25 mm in the longer axis, the ratio of microscopic diagnosable cases was 100 % (7/7) for DNAB and 42.9 % (3/7) for FNA.

CONCLUSIONS

DNAB is a novel method that can obtain more tissue than FNA for small gastric SMT.