Suggested cutoff tumor size for management of small EUS-suspected gastric gastrointestinal stromal tumors

Results of the interim analysis of a prospective, multicenter, observational study of small subepithelial lesions in the stomach

OBJECTIVES

Long-term outcomes of gastric subepithelial lesions have not been elucidated. To reveal the natural history, we initiated a prospective, 10-year follow-up of patients with small (≤20 mm) gastric subepithelial lesions in September 2014. Here, we report the results of an interim analysis of a prospective observational study.

METHODS

In total, 567 patients with 610 lesions were prospectively registered between September 2014 and August 2016. The location, size, morphology, and number of subepithelial lesions were recorded on a web-based case report form. This study has been conducted as an Academic Committee Working Group of the Japan Gastroenterological Endoscopy Society.

RESULTS

The endoscopic follow-up period was 4.60 ± 1.73 years (mean ± standard deviation), and survival data were investigated for 5.28 ± 1.68 years. This interim analysis revealed that the estimated cumulative incidence of a size increase ≥5 mm, after accounting for patients' death and resection of the tumor as competing risk events, was 4.5% at 5 years. In addition, the estimated cumulative incidence of lesion size increase ≥5 mm or resection of lesions was 7.9% at 5 years, and that of size increase ≥10 mm or resection of lesions was 4.5% at 5 years.

CONCLUSION

These results indicate that approximately one in 13 patients with small (≤20 mm) gastric subepithelial lesions may require resection or further investigation for increased tumor size (≥5 mm) within 5 years.

Small Gastric Stromal Tumors: An Underestimated Risk

BACKGROUND AND OBJECTIVES

Small gastrointestinal stromal tumors (GISTs) are defined as tumors less than 2 cm in diameter, which are often found incidentally during gastroscopy. There is controversy regarding the management of small GISTs, and a certain percentage of small GISTs become malignant during follow-up. Previous studies which used Sanger targeted sequencing have shown that the mutation rate of small GISTs is significantly lower than that of large tumors. The aim of this study was to investigate the overall mutational profile of small GISTs, including those of wild-type tumors, using whole-exome sequencing (WES) and Sanger sequencing.

METHODS

Thirty-six paired small GIST specimens, which were resected by endoscopy, were analyzed by WES. Somatic mutations identified by WES were confirmed by Sanger sequencing. Sanger sequencing was performed in an additional 38 small gastric stromal tumor samples for examining hotspot mutations in KIT, PDGFRA, and BRAF.

RESULTS

Somatic C-KIT/PDGFRA mutations accounted for 81% of the mutations, including three novel mutation sites in C-KIT at exon 11, across the entire small gastric stromal tumor cohort (n = 74). In addition, 15% of small GISTs harbored previously undescribed BRAF-V600E hotspot mutations. No significant correlation was observed among the genotype, pathological features, and clinical classification.

CONCLUSIONS

Our data revealed a high overall mutation rate (~96%) in small GISTs, indicating that genetic alterations are common events in early GIST generation. We also identified a high frequency of oncogenic BRAF-V600E mutations (15%) in small GISTs, which has not been previously reported.

Efficacy of endoscopic ultrasound in the evaluation of small gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) with a diameter of < 2 cm are called small GISTs. Currently, endoscopic ultrasound (EUS) is widely used as a regular follow-up method for GISTs, which can also provide a preliminary basis for judging the malignancy potential of lesions. However, there are no studies on the accuracy of EUS to assess the malignant potential of small GISTs.

AIM

To evaluate the efficacy of EUS in the diagnosis and risk assessment of small GISTs.

METHODS

We collected data from patients with small GISTs who were admitted to Shengjing Hospital of China Medical University between October 2014 and July 2019. The accurate diagnosis and risk classifications of patients were based on the pathological assessment according to the modified National Institute of Health criteria after endoscopic resection or laparoscopic surgery. Preoperative EUS features (marginal irregularity, cystic changes, homogeneity, ulceration, and strong echogenic foci) were retrospectively analyzed. The assessment results based on EUS features were compared with the pathological features.

RESULTS

A total of 256 patients (69 men and 187 women) were enrolled. Pathological results included 232, 16, 7, and 1 very low-, low-, intermediate-, and high-risk cases, respectively. The most frequent tumor location was the gastric fundus (78.1%), and mitoses were calculated as > 5/50 high power field in 8 (3.1%) patients. Marginal irregularity, ulceration, strong echo foci, and heterogeneity were detected in 1 (0.4%), 2 (0.8%), 22 (8.6%), and 67 (65.1%) patients, respectively. However, cystic changes were not detected. Tumor size was positively correlated with the mitotic index (P < 0.001). Receiver operating curve analysis identified 1.48 cm as the best cut-off value to predict malignant potential (95% confidence interval: 0.824–0.956). EUS heterogeneity with tumor diameters > 1.48 cm was associated with higher risk classification (P < 0.05).

CONCLUSION

Small GISTs (diameters > 1.48 cm) with positive EUS features should receive intensive surveillance or undergo endoscopic surgery. EUS and dissection are efficient diagnostic and therapeutic approaches for small GISTs.

Clinical outcomes of endoscopic treatment for gastric gastrointestinal stromal tumors: a single-center study of 240 cases in China

BACKGROUND AND AIMS

Endoscopic resection (ER) gradually becomes an important treatment method for gastrointestinal stromal tumors (GISTs). The aim of this study is to evaluate the efficacy and safety of ER of gastric GISTs.

METHODS

This retrospective study included 240 patients with gastric GISTs who underwent ER at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2010 to December 2019. The clinicopathologic, endoscopic and follow-up data of the patients were collected and analyzed.

RESULTS

The mean maximum tumor diameter was 1.67 ± 1.00 cm (range 0.2-6.5 cm), of which 156 cases (65.00%) were small gastric GISTs (tumor diameter < 2 cm). A total of 43 patients (17.92%) had perioperative bleeding, including 40 cases (16.67%) of minor bleeding and three cases (1.25%) of major bleeding. Perioperative perforation occurred in 101 patients (42.08%), of which 51 patients (21.25%) were active perforation and 50 patients (20.83%) were passive perforation. The en bloc resection rate was 97.08% (233/240), and seven cases (2.92%) had piecemeal resection. There were three cases (1.92%) of small gastric GISTs at intermediate risk and one case (0.64%) at high risk. A total of 193 patients were followed up, and no tumor residual, recurrence or metastasis occurred within a median follow-up time of 30 months (range 1-127 months).

CONCLUSIONS

Endoscopic treatment for gastric GISTs is safe and effective. Piecemeal resection does not seem to be related to the patient's prognosis. Endoscopic resection can be performed if patients are willing to remove small gastric GISTs.

A Nomogram for Predicting Laparoscopic and Endoscopic Cooperative Surgery during the Endoscopic Resection of Subepithelial Tumors of the Upper Gastrointestinal Tract

Background: Considering the widespread use of esophagogastroduodenoscopy, the prevalence of upper gastrointestinal (GI) subepithelial tumors (SET) increases. For relatively safer removal of upper GI SETs, endoscopic submucosal dissection (ESD) has been developed as an alternative to surgery. This study aimed to analyze the outcome of endoscopic resection for SETs and develop a prediction model for the need for laparoscopic and endoscopic cooperative surgery (LECS) during the procedure. Method: We retrospectively analyzed 123 patients who underwent endoscopic resection for upper GI SETs between January 2012 and December 2020 at our institution. Intraoperatively, they underwent ESD or submucosal tunneling endoscopic resection (STER). Results: ESD and STER were performed in 107 and 16 patients, respectively. The median age was 55 years, and the average tumor size was 1.5 cm. En bloc resection was achieved in 114 patients (92.7%). The median follow-up duration was 242 days without recurrence. Perforation occurred in 47 patients (38.2%), and 30 patients (24.4%) underwent LECS. Most perforations occurred in the fundus. Through multivariable analysis, we built a nomogram that can predict LECS requirement according to tumor location, size, patient age, and sex. The prediction model exhibited good discrimination ability, with an area under the curve (AUC) of 0.893. Conclusions: Endoscopic resection is a noninvasive procedure for small upper-GI SETs. Most perforations can be successfully managed endoscopically. The prediction model for LECS requirement is useful in treatment planning.

Endoscopic Resection for Gastric Subepithelial Tumor with Backup Laparoscopic Surgery: Description of a Single-Center Experience

The aim of this study was to analyze patients who underwent endoscopic resection (ER) for gastric subepithelial tumors (SETs) with a high probability of surgical intervention. Between January 2013 and January 2021, 83 patients underwent ER at the operation theater and 27 patients (32.5%) required backup surgery mainly due to incidental perforation or uncontrolled bleeding despite endoscopic repairing. The tumor was predominantly located in the upper-third stomach (81%) with a size ≤ 2 cm (69.9%) and deep to the muscularis propria (MP) layer (92.8%) but there were no significant differences between two groups except tumor exophytic growth as a risk factor in the surgery group (37% vs. 0%, p < 0.0001). Patients in the ER-only group had shorter durations of procedure times (60 min vs. 185 min, p < 0.0001) and lengths of stay (5 days vs. 7 days, p < 0.0001) but with a higher percentage of overall morbidity graded III (0% vs. 7.1%, p = 0.1571). After ER, five patients (6%) had delayed perforation and two (2.4%) required emergent laparoscopic surgery. Neither recurrence nor gastric stenosis was reported during long-term surveillance. Here, we provide a minimally invasive strategy of endoscopic resection with backup laparoscopic surgery for gastric SETs.

Novel endoscopic management for small gastric submucosal tumors: A single-center experience (with video)

BACKGROUND AND AIMS

To explore the novel treatment of small gastric submucosal tumors (SMTs) originating from the muscularis propria layer (SMT-MPs), we utilized endoscopic band ligation (EBL) with a precut of the covering mucosa.

METHODS

From Jan. 2012 to Dec. 2019, 111 patients with 124 gastric SMT-MPs were treated by precutting EBL. The clinical characteristics, operation duration, postoperative adverse events, and follow-up profiles were retrospectively collected.

RESULTS

A total of 124 tumors from 111 patients were successfully treated by precutting EBL. No adverse events, including perforation and major bleeding, were observed. Furthermore, 93 patients (83.8%) underwent endoscopic surveillance postoperatively, and during the follow-up period, no local recurrence was detected.

CONCLUSIONS

Precutting EBL appears to be a safe and simple method for removing gastric SMT-MPs < 16 mm (mainly indicated for potentially malignant GISTs), but further studies with longer follow-up are needed to assess the radicality of this intervention.

Efficacy and safety of endoscopic resection in treatment of small gastric stromal tumors: A state-of-the-art review

Gastrointestinal stromal tumors can occur in any part of the gastrointestinal tract, but gastric stromal tumors (GSTs) are the most common. All GSTs have the potential to become malignant, and these can be divided into four different grades by risk from low to high: Very low risk, low risk, medium risk, and high risk. Current guidelines all recommend early complete excision of GSTs larger than 2 cm in diameter. However, it is not clear whether small GSTs (sGSTs, i.e., those smaller than 2 cm in diameter) should be treated as early as possible. The National Comprehensive Cancer Network recommends that endoscopic ultrasonography-guided (EUS-guided) fine-needle aspiration biopsy and imaging (computed tomography or magnetic-resonance imaging) be used to assess cancer risk for sGSTs detected by gastroscopy to determine treatment. When EUS indicates a higher risk of tumor, surgical resection is recommended. There are some questions on whether sGSTs also require early treatment. Many studies have shown that endoscopic treatment of GSTs with diameters of 2-5 cm is very effective. We here address whether endoscopic therapy is also suitable for sGSTs. In this paper, we try to explain three questions: (1) Does sGST require treatment? (2) Is digestive endoscopy a safe and effective means of treating sGST? and (3) When sGSTs are at different sites and depths, which endoscopic treatment method is more suitable?

Preoperative imaging of gastric GISTs underestimates pathologic tumor size: A retrospective, single institution analysis

BACKGROUND

How well imaging size agrees with pathologic size of gastric gastrointestinal stromal tumors (GISTs) is unknown. GIST risk stratification is based on pathologic size, location, and mitotic rate. To inform decision making, the size discrepancy between imaging and pathology for gastric GISTs was investigated.

METHODS

Imaging and pathology reports were reviewed for 113 patients. Bland-Altman analyses and intraclass correlation (ICC) assessed agreement of imaging and pathology. Changes in clinical risk category due to size discrepancy were identified.

RESULTS

Computed tomography (CT) (n = 110) and endoscopic ultrasound (EUS) (n = 50) underestimated pathologic size for gastric GISTs by 0.42 cm, 95% confidence interval (CI): (0.11, 0.73), p = 0.008 and 0.54 cm, 95% CI: (0.25, 0.82), p < 0.001, respectively. ICCs were 0.94 and 0.88 for CT and EUS, respectively. For GISTs ≤ 3 cm, size underestimation was 0.24 cm for CT (n = 28), 95% CI: (0.01, 0.47), p = 0.039 and 0.56 cm for EUS (n = 26), 95% CI: (0.27, 0.84), p < 0.0001. ICCs were 0.72 and 0.55 for CT and EUS, respectively. Spearman's correlation was ≥0.84 for all groups. For GISTs ≤ 3 cm, 6/28 (21.4% p = 0.01) on CT and 7/26 (26.9% p = 0.005) on EUS upgraded risk category using pathologic size versus imaging size. No GISTs ≤ 3 cm downgraded risk categories. Size underestimation persisted for GISTs ≤ 2 cm on EUS (0.39 cm, 95% CI: [0.06, 0.72], p = 0.02, post hoc analysis).

CONCLUSION

Imaging, particularly EUS, underestimates gastric GIST size. Caution should be exercised using imaging alone to risk-stratify gastric GISTs, and to decide between surveillance versus surgery.

Over-the-Scope Clip-Associated Endoscopic Muscular Dissection for Seven Cases of Small Gastric Submucosal Tumor: A Video-Based Case Series

Objectives

To evaluate the methodology, feasibility, safety, and efficacy of a novel method called over-the-scope clip- (OTSC-) associated endoscopic muscular dissection for small GSMT.

Methods

A pilot study on small GSMT diameter ≤ 1 cm was performed. OTSC-associated endoscopic muscular dissection was based on the requirement of OTSC apparatus and ESD technique; after ligaturing the bottom of small GSMT by OTSC, ESD was performed to resect the tumors, and the wounds of ESD were closed by clips finally. All the patients were followed up for more than 3 months, and the complications during and after OTSC-associated endoscopic muscular dissection were recorded.

Results

A total of 7 consecutive patients with small GSMT were included. All tumors were completely dissected without any perforation or infection during and after the procedure in all cases, while three patients had mild abdominal pain, and one experienced postoperative bleeding after the procedure which was treated by the endoscopy with titanium clips. All the patients were followed by endoscopy three months later, all the wounds healed well, and all the OTSCs were still in the gastric wall.

Conclusions

OTSC-associated endoscopic muscular dissection as a novel endoscopic interventional therapy should be a convenient, safe, and effective therapy for small GSMT. The short-time outcome is excellent, whereas long-term effect is unclear, and the further follow-up is needed to schedule.

A scoring model for radiologic diagnosis of gastric leiomyomas (GLMs) with contrast-enhanced computed tomography (CE-CT): Differential diagnosis from gastrointestinal stromal tumors (GISTs)

OBJECTIVES

To investigate CT findings and develop a diagnostic score model to differentiate GLMs from GISTs.

METHODS

This retrospective study included 109 patients with pathologically confirmed GLMs (n = 46) and GISTs (n = 63) from January 2013 to August 2018 who received CE-CT before surgery. Demographic and radiological features was collected, including lesion location, contour, presence or absence of intralesional necrosis and ulceration, growth pattern, whether the tumor involved EGJ, the long diameter (LD) /the short diameter (SD) ratio, pattern and degree of lesion enhancement. Univariate analyses and multivariate logistic regression analyses were performed to identify independent predictors and establish a predictive model. Independent predictors for GLMs were weighted with scores based on regression coefficients. A receiver operating characteristic (ROC) curve was created to determine the diagnostic ability of the model. Overall score distribution was divided into four groups to show differentiating probability of GLMs from GISTs.

RESULTS

Five CT features were the independent predictors for GLMs diagnosis in multivariate logistic regression analysis, including esophagogastric junction (EGJ) involvement (OR, 367.9; 95 % CI, 5.8-23302.8; P =  0.005), absence of necrosis (OR, 11.9; 95 % CI, 1.0-138. 1; P =  0.048) and ulceration (OR, 151.9; 95 % CI, 1.4-16899.6; P =  0.037), degree of enhancement (OR, 9.3; 95 % CI, 3.2-27.4; P <  0.001), and long diameter/ short diameter (LD/SD) ratio (OR,170.9; 95 % CI, 8.4-3493.4; P =  0.001). At a cutoff of 9 points, AUC for this score model was 0.95, with 95.65 % sensitivity, 79.37 % specificity, 77.19 % PPV, 96.15 % NPV and 86.24 % diagnostic accuracy. An increasing trend was showed in diagnostic probability of GLMs among four groups based on the score (P <  0.001).

CONCLUSIONS

The newly designed scoring system is reliable and easy-to-use for GLMs diagnosis by distinguishing from GISTs, including EGJ involvement, absence of ulceration and necrosis, mild enhancement and high LD/SD ratio. The overall score of model ranged from 1 to 17 points, which was divided into 4 groups: 1-7 points, 7-10 points, 10-13 points and 13-17 points, with a diagnostic probability of GLMs 0%, 45 %, 83 % and 100 %, respectively.

Peroral endoscopic tumor resection (POET) with preserved mucosa technique for management of upper gastrointestinal tract subepithelial tumors

BACKGROUND

Third space endoscopy technique facilitates therapeutic endoscopy in subepithelial space. This study aimed to investigate peroral endoscopic tumor resection (POET) with preserved mucosa technique for upper gastrointestinal tract subepithelial tumors (UGI-SETs) removal.

METHODS

Between February 2011 and December 2019, consecutive patients with SETs of esophagus and stomach who underwent POET for enlarging size during follow-up, malignant endoscopic ultrasound features or by patient's request were enrolled. Demographic, endoscopic and pathological data were analyzed retrospectively.

RESULTS

Totally 18 esophageal (mean ± SD age, 55.23 ± 4.15 year-old, 38.89% female) and 30 gastric (52.65 ± 2.43 year-old, 53.33% female) SETs in 47 patients (one with both esophageal and gastric lesions) were resected. The mean (± SD) endoscopic/pathological tumor size, procedure time, en-bloc/complete resection rate, and hospital stays of esophageal and gastric SET patients were 12.36 (± 7.89)/11.86 (± 5.67) and 12.57 (± 6.25)/12.35 (± 5.73) mm, 14.86 (± 6.15) and 38.21 (± 15.29) minutes, 88.89%/94.44% and 86.77%/93.30%, and 4.14 (± 0.21) and 4.17 (± 0.20) days, respectively. The overall complication rate was 18.75%, including 6 self-limited fever and 3 pneumoperitoneum relieved by needle puncture. There was no mortality or recurrence reported with mean follow-up period of 23.74 (± 4.12) months.

CONCLUSIONS

POET is a safe and efficient third space endoscopic resection technique for removal of UGI-SETs less than 20 mm. Long term data are warranted to validate these results.

Which size is the best cutoff for primary small gastric gastrointestinal stromal tumor?

Background

The biological behavior of primary small gastric gastrointestinal stromal tumor (gGIST) is indolent. The cutoff size categorizing small gGIST continues to be controversial. To date, there is no consensus regarding whether it should be 1 cm, 2 cm, or another size. We aimed to find a new cutoff size.

Methods

Retrospective clinicopathological and prognosis data of patients with small gGIST from January 1998 to January 2015 were collected among five medical centers in southern China. Tumor size was divided into two groups: <1 cm (Mirco group) and 1-2 cm (Small group). We compared the clinicopathological index and prognosis between these two groups and identified a new cutoff size to define small gGIST.

Results

During this 18-year period, there were 276 patients with primary small gGIST treated at these five medical centers. The range of tumor size was 0.2-2.0 cm. The median tumor size was 1.0 cm. The range of the mitotic count was 0-70/50 high power fields (HPFs) with counts ≤5/50 HPFs in 259 patients (93.8%), 5< counts ≤10/50 HPFs in 7 patients (2.5%), and counts >10/50 HPFs in 10 patients (3.6%). The median follow-up time was 38 months (3-156 months). The 5-year overall survival rate was 98.7% in the entire group. Using Pearson correlation analysis, there was a positive correlation between the mitotic count and tumor size as a continuous variable (r=0.164, P=0.006). There were 137 patients in the Micro group and 139 cases in the Small group. In the Micro group, mitotic counts were ≤5/50 HPFs in 134 patients, 5< counts ≤10/50 HPFs in 0 patients, and counts >10/50 HPFs in 3 patients; mitotic counts in the Small group were counts ≤5/50 HPFs in 125 patients, 5< counts ≤10/50 HPFs in 7 patients, >10/50 HPFs in 7 patients. There was a statistically significant difference between these two groups (P=0.002); the Small group had more intermediate/high-risk cases. Using the receiver operating characteristic curve (ROC curve), we observed that 1.15 cm was the new cutoff size to separate low-risk cases and intermediate/high-risk cases (AUC =0.707, P=0.004, sensitivity =0.824, 1-specificity =0.429).

Conclusions

Primary small gGIST has a good prognosis; gGIST <1 cm can be regarded as benign tumors that only requires endoscopic ultrasonography (EUS) follow-up. The proportion of potential intermediate/high-risk disease is high for patients with 1-2 cm gGIST. These patients should be treated with caution and the tumors should be resected if necessary. These results indicate that 1.15 cm may be the new cutoff size to separate small gGIST from large gGIST, but further studies are needed for verification.

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.

Clinical evaluation of endoscopic resection for treatment of large gastric stromal tumors

BACKGROUND

Gastric stromal tumor is a digestive tract mesenchymal tumor with malignant potential, and endoscopic techniques have been widely used in the treatment of gastric stromal tumors, but there is still controversy over their use for large gastric stromal tumors (≥ 3 cm).

AIM

To evaluate the clinical long-term efficacy and safety of endoscopic resection for large (≥ 3 cm) gastric stromal tumors.

METHODS

All patients who underwent endoscopic resection or surgery at our hospital from 2012 to 2017 for pathologically confirmed gastric stromal tumor with a maximum diameter of ≥ 3 cm were collected. The clinical data, histopathologic characteristics of the tumors, and long-term outcomes were recorded.

RESULTS

A total of 261 patients were included, including 37 patients in the endoscopy group and 224 patients in the surgical group. In the endoscopy group, the maximum tumor diameter was 3-8 cm; the male: Female ratio was 21/16; 34 cases had low-risk tumors, 3 had intermediate-risk, and 0 had high-risk; the mean follow-up time was 30.29 ± 19.67 mo, no patient was lost to follow-up, and no patient received chemotherapy after operation; two patients with recurrence had low-risk stromal tumors, and neither had complete resection under endoscopy. In the surgical group, the maximum tumor diameter was 3-22 cm; the male: Female ratio was 121/103; 103 cases had low-risk tumors, 75 had intermediate-risk, and 46 had high-risk; the average follow-up time was 38.83 ± 21.50 mo, 53 patients were lost to follow-up, and 8 patients had recurrence after operation (6 cases had high-risk tumors, 1 had intermediate-risk, and 1 had low-risk). The average tumor volume of the endoscopy group was 26.67 ± 26.22 cm³ (3.75-120), all of which were less than 125 cm³. The average volume of the surgical group was 273.03 ± 609.74 cm³ (7-4114). Among all patients with a tumor volume < 125 cm³, 7 with high-risk stromal tumors in the surgical group (37.625 cm³ to 115.2 cm³) accounted for 3.8% (7/183); of those with a tumor volume < 125 cm³, high-risk patients accounted for 50% (39/78). We found that 57.1% (12/22) of patients with high-risk stromal tumors also had endoscopic surface ulcer bleeding and tumor liquefaction on ultrasound or abdominal computed tomography; the ratio of tumors positive for both in high-risk stromal tumors with a volume < 125 cm³ was 60% (3/5).

CONCLUSION

Endoscopic treatment is safe for 95.5% of patients with gastric stromal tumors with a tumor diameter ≥ 3 cm and a volume of < 125 cm³ without endoscopic surface ulcer bleeding or CT liquefaction.

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.

LAPAROENDOSCOPIC TRANSGASTRIC RESECTION OF SUBEPITHELIAL JUXTACARDIAC TUMORS

BACKGROUND

With a prevalence of 0.4-3.5%, subepithelial lesions of the upper digestive tract are discovered during endoscopic procedures. Treatment depends on etiological and pathophysiological information, ability to diagnose and the different technical resources available.

AIM

To demonstrate the effectiveness of a surgical technique that combines endoscopy and videolaparoscopy in the transgastric resection of subepithelial juxtacardic lesions.

METHOD

The patients were assisted with a technical combination between endoscopy and laparoscopy. After diagnosis of subepithelial tumor, intraoperative endoscopy was performed after pneumoperitoneum and placement of laparoscopic tweezers. Through endoscopy, the following steps were performed: demarcation of surgical margins, visualization of the intragastric image for the laparoscopic procedure and removal of the surgical specimen. By laparoscopy the following steps were performed: intragastric intra-abdominal access, resection of the part and closure of the gaps.

RESULTS

This technique was applied in two cases in order to evaluate its initial results. There were two videolaparoendoscopic resections of juxtacardiac gastric tumors of the posterior wall. Both had their endoscopic diagnosis confirmed. After laparoendoscopic and tomographic and/or ecoendoscopic diagnostic complementation and preoperative performance, the laparoendoscopic procedure was indicated. The patients had a good recovery, with a short hospitalization time and no complications.

CONCLUSION

The combined use of videolaparoscopy and endoscopy is a safe and effective technique for transgastric resection of juxtacardiac subepithelial lesions. It may be important for definitive diagnosis of the tumor.

Endosonographic surveillance of 1-3 cm gastric submucosal tumors originating from muscularis propria

AIM

To observe the natural course of 1-3 cm gastric submucosal tumors originating from the muscularis propria (SMTMPs).

METHODS

By reviewing the computerized medical records over a period of 14 years (2000-2013), patients with 1-3 cm gastric SMTMPs who underwent at least two endoscopic ultrasound (EUS) examinations were enrolled. Tumor progression was defined as a ≥ 1.2 times enlargement in tumor diameter observed during EUS surveillance. All patients were divided into stationary and progressive subgroups and further analyzed. We also reviewed the patients in the progressive subgroup again in 2016.

RESULTS

A total of 88 patients were studied, including 25 in the progressive subgroup. The mean time of EUS surveillance was 24.6 mo in the stationary subgroup and 30.7 mo in the progressive subgroup. Risk factors for tumor progression included larger tumor size and irregular border. Initial tumor size > 14.0 mm may be considered a cut-off size for predicting tumor progression. Seventeen patients underwent surgery, of whom 13 had gastrointestinal stromal tumors (GISTs) and 4 had leiomyomas. Tumor progression was found only in patients with GISTs. All of the tumors exhibited benign behaviors without metastasis until 2016.

CONCLUSION

Most 1-3 cm gastric SMTMPs (71.6%) are indolent. Tumor progression was found only in GISTs, and it is a good predictor for differentiating GISTs from leiomyomas. Predictors of tumor progression include larger tumor size (> 14.0 mm) and irregular border.

The cut-off value of tumor size and appropriate timing of follow-up for management of minimal EUS-suspected gastric gastrointestinal stromal tumors

Backgroud

The detectable rate of minimal gastric GISTs has continuously increased. While the surveillance and management of GIST <2 cm have been deemed controversial or lack evidence-based approaches.  The aim of the current study is to propose a cut-off value of tumor size for treatment policy and the appropriate timing for endoscopic ultrasonography (EUS) follow-up in the minimal EUS-suspected gastric GIST patients.

Methods

A single-institution retrospective study was performed. 69 patients with EUS-suspected gastric GISTs were studied from November 2008 to March 2015. 69 patients with minimal gastric GISTs ≤2 cm diagnosed by EUS were followed for a mean period of 29 months (range, 12 to 70). An at least 20% increase of the maximal diameter of the tumors was set as a significant change.

Results

During follow-up, Of the 69 minimal EUS-suspected GISTs, 16 (23.2%) showed significant changes in size. 11 out of 69 GISTs (15.9%), 6 out of 43 GISTs (14.0%), 7 out of 30 GISTs (23.3%) showed significant changes in size, at 1 year, 2 years, and more than 3 years respectively. The receiver operating characteristic curve analysis showed that the tumor size cut-off was 9.5 mm. Only 4.7 and 3.7% of gastric EUS-suspected GISTs of <9.5 mm in size showed significant changes at 1 year and 2 years, while 9.5% at more than 3 years. 34.6, 31.3 and 55.6% of gastric EUS-suspected GISTs of ≥ 9.5 mm in size showed significant changes at 1 year, 2 years and more than 3 years.

Conclusions

Minimal EUS-suspected GISTs, larger than 9.5 mm may be associated with significant progression. The patients with a ≥ 9.5 mm GIST should have a EUS 6–12months, while <9.5 mm GIST may have a EUS extended to every 2–3 years.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0567-4) contains supplementary material, which is available to authorized users.

Cancer Measurement at Ultrasound: State of the Art

Reliable and reproducible tumor measurement is fundamental in the oncologic decision making. In this article, we first highlight the importance of a precise tumor measurement, reviewing the correct modality of measuring tumor lesions at ultrasound. Then we analyze the measurement discrepancies between ultrasound and pathology as well as the discrepancies reported between ultrasound and other imaging modalities. Thereafter, basing on the existent literature and on our experience, we discuss the factors influencing the tumor size measurements at ultrasound. Finally, we illustrate the current strategies to improve the effectiveness of cancer lesions measurement.

Comparison between submucosal tunneling endoscopic resection and endoscopic full-thickness resection for gastric stromal tumors originating from the muscularis propria layer

BACKGROUND

Both submucosal tunneling endoscopic resection (STER) and endoscopic full-thickness resection (EFTR) are effective method for treating gastric gastrointestinal stromal tumors (GISTs); however, little is known about the comparison between STER and EFTR. The aim of the study was to compare the safety and efficacy of STER and EFTR for treating gastric GIST.

METHODS

We retrospectively collected the clinical data about patients with gastric GISTs who received STER or EFTR at our hospital from April 2011 to June 2016. Epidemiological data (gender, age), tumor size, procedure-related parameters, complications, length of stay, cost and follow-up data were compared between STER and EFTR.

RESULTS

A total of 52 patients were enrolled, and 20 of them received STER, while the other 32 cases received EFTR. There was no significant difference between the two groups in terms of gender, age, concomitant diseases, tumor size, en bloc resection rate, operation time, complications, pathohistological grade of GIST, hospital stay and cost (P > 0.05). However, patients who received EFTR had a longer suture time and needed more clips to close the gastric-wall defect (STER vs EFTR, 291.5 ± 68.7 vs 380.6 ± 96.9s and 6.0 ± 1.2 vs 7.6 ± 1.6, P < 0.05). No recurrence was noted in the STER and EFTR groups during a mean follow-up of 10.9 and 23.8 months, respectively.

CONCLUSIONS

The treatment efficacy between STER and EFTR for treating gastric GISTs was comparable, and a large-scale, randomized study is necessary for a more confirmed conclusion.

Comparison of Endoscopic and Open Resection for Small Gastric Gastrointestinal Stromal Tumor

The National Comprehensive Cancer Network recommends conservative follow-up for gastric gastrointestinal stromal tumors (GISTs) less than 2 cm. We have previously reported that the mitotic index of 22.22% of small gastric GISTs exceeded 5 per 50 high-power fields and recommended that all small gastric GISTs should be resected once diagnosed. The aim of the present study is to compare the safety and outcomes of endoscopic and open resection of small gastric GISTs. From May 2010 to March 2014, a total of 90 small gastric GIST patients were enrolled in the present study, including 40 patients who underwent surgical resection and 50 patients who underwent endoscopic resection. The clinicopathological characteristics, resection-related factors, and clinical outcomes were recorded and analyzed. The clinicopathological characteristics were comparable between the two groups except for tumor location and DOG-1 expression. Compared with the surgical resection group, the operation time was shorter (P = .000), blood loss was less (P = .000), pain intensity was lower (P < .05), duration of first flatus and defecation was shorter (P < .05), and medical cost of hospitalization was lower (P = .027) in the endoscopic resection group. The complications and postoperative hospital stay were comparable between the two groups. No in situ recurrence or liver metastasis was observed during follow-up. Endoscopic resection of small gastric GISTs is safe and feasible compared with surgical resection, although perforation could not be totally avoided during and after resection. The clinical outcome of endoscopic resection is also favorable.

Clinicopathological features and prognosis of small gastrointestinal stromal tumors outside the stomach

The aim of the present study was to assess the clinicopathological features and prognostic factors of primary small gastrointestinal stromal tumors (GISTs) outside the stomach. The clinical data, clinicopathological features and prognostic factors of 20 patients with a pathologically-confirmed diagnosis of non-gastric GIST that were treated at Liaoning Cancer Hospital & Institute between July 2006 and December 2013 were retrospectively analyzed. In total, 15 patients were male and 5 were female, with a median age of 58 years (range, 44–82 years). A change in bowel habits was the original symptom of rectal small GISTs in 6 out of 8 patients, while patients with small GISTs in other locations demonstrated no overt symptoms and the lesions were detected by systematic examinations of other diseases or abdominal surgical procedures performed on other organs. In total, 19 patients out of the total 20 patients underwent surgery, and 1 patient with rectal GIST received continuous oral imatinib mesylate (400 mg once a day) instead of undergoing surgery. The mean diameter of tumors was 1.55±0.54 cm (range, 0.3–2.0 cm) and the median was 1.70 cm. The pathomorphology of the lesions was mainly spindle cell, and immunohistochemistry revealed the expression rate of cluster of differentiation (CD)117, CD34 and discovered on GIST-1 were 85, 80 and 70%. According to the mitosis index, small rectal GISTs were more frequent compared with other positions (P<0.05), while the frequency of small GISTs >1 cm in size was not significantly different from the frequency of small GISTs ≤1 cm in size (P=0.995). All 20 patients were followed up, with a median follow-up duration of 49.5 months (range, 10.5–94.4 months). At the end of the follow-up period, tumor recurrence occurred in 5 patients and 1 patient succumbed following progression. According to the analysis of the tumor sites, the RFS time of patients with small rectal GISTs was significantly different than the RFS time in patients with small GISTs in other positions. The clinical symptoms of non-gastric small GISTs were not evident and were challenging to detect. Small GISTs, regardless of size, possessed malignant potential and once detected, GISTs should be surgically resected. Lesions located in the rectum demonstrated an increased degree of malignancy and were more likely to recur. The tumor size and Ki67 index could not be considered as prognostic factors of non-gastric small GISTs.

Submucosal tumors: comprehensive guide for the diagnosis and therapy of gastrointestinal submucosal tumors

Small submucosal tumors (SMT) without symptoms are frequently found by endoscopic and radiological examinations. To find proper diagnostic measures and therapeutic indications for histologically undiagnosed SMT, we reviewed published articles in PubMed between 1990 and March 2013 using the key words 'submucosal tumor' and the name of a specific disease. SMT is observed in a wide range of gastrointestinal (GI) diseases and conditions, including compression by extra-GI organs and lesions, congenital tumors, inflammation, and benign as well as malignant neoplastic lesions. In the diagnosis of diseases and decision-making for therapy, endoscopic ultrasonography (EUS) and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) may play a key role. Symptomatic SMT and SMT histologically diagnosed as malignant or potentially malignant tumors such as gastrointestinal stromal tumor (GIST) should be treated by surgery. SMT >5 cm, SMT increasing in size and those with'high-risk features' including irregular border, heterogeneous internal echo such as anechoic area, and heterogeneous enhancement by contrast media may also be removed by surgery. Laparoscopic approach is feasible for gastric GIST <5 cm and this is considered less invasive than the open approach. Emerging techniques using flexible endoscopes appear less invasive, but require further evidence and are still under clinical study. Correct diagnosis of SMT is challenging; however, EUS and EUS-FNA are useful in the histological diagnosis and clinical decision-making. In the future, minimally invasive approaches may be a mainstream of surgical treatment for small SMT.