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

Efficacy and Safety of Endoscopic Resection for Gastric Gastrointestinal Stromal Tumors Originating from the Muscularis Propria

BACKGROUND

The role of endoscopic resection (ER) in gastric gastrointestinal stromal tumors (GISTs) has not been fully elucidated.

AIMS

The purpose of this work was to evaluate the clinical effectiveness and safety of ER in patients with GISTs originating from the muscularis propria (MP).

METHODS

A total of 233 consecutive patients with gastric GISTs originating from the MP layer, who underwent ER between February 2012 and May 2023, were included in this study. Clinical characteristics, tumor features, and outcomes were recorded and compared between patients who underwent en bloc resection and piecemeal resection.

RESULTS

Among the 233 patients, the median size of GISTs was 12 mm (range 5-60 mm). Risk assessment categorized 190 patients as very low risk, 26 as low risk, 10 as moderate risk, and 7 as high risk. The procedures performed included endoscopic submucosal excavation (127 cases), endoscopic full-thickness resection (103 cases), and submucosal tunneling endoscopic resection (3 cases). The complete and R0 resection rate was 93.1%. Complications occurred in 4.7% of cases (perioperative perforations 1.7%, perioperative bleeding 1.3%, both 0.9%), resulting in conversion to surgery in 1.3% of cases. Risk factors associated with piecemeal resection were tumor size [odds ratio (OR) 0.402, 95% confidence interval (CI) 0.207-0.783; P = 0.007] and shape (OR 0.045, 95% CI 0.009-0.235; P < 0.001).

CONCLUSIONS

ER is proven to be an effective and reasonably safe approach for gastric GISTs originating from the MP. Notably, larger tumor size and irregular shape are identified as risk factors for piecemeal resection during ER procedures.

Prognostic impact of positive microscopic margins (R1 resection) in patients with GIST (gastrointestinal stromal tumours): Results of a multicenter European study

BACKGROUND

Although several prognostic factors in GIST have been well studied such as tumour size, mitotic rate, or localization, the influence of microscopic margins or R1 resection remains controversial. The aim of this study was to evaluate the influence of R1 resection on the prognosis of GIST in a large multicentre retrospective series of patients.

METHODS

From 2001 to 2013, 1413 patients who underwent surgery for any site of GIST were identified from 61 European centers. 1098 patients were included, excluding synchronous metastases, concurrent malignancies, R2 resection or GIST recurrence. Tumour rupture (TR) was reclassified according to the Oslo sarcoma classification. Cox proportional hazards ratio and Kaplan-Meier survival estimates were used to analyse 5-year recurrence-free survival (RFS).

RESULTS

Of 1098 patients, 38 (3%) underwent R1 resection with a risk of TR of 11%. The 5-year RFS was 89.6% with a median follow-up of 81 months [range: 31.2-152 months]. On univariate analysis, lower RFS was significantly associated with R1 resection [HR = 2.13; p = 0.04], high risk score according to the modified NIH classification, administration of adjuvant therapy [HR = 2.24; p < 0.001] and intraoperative complications [HR = 2.82; p < 0.001]. Only intraoperative complications [HR = 1.79; p = 0.02] and high risk according to the modified NIH classification including the updated definition of TR [HR = 3.43; p = 0.04] remained significant on multivariate analysis.

CONCLUSION

This study shows that positive microscopic margins are not an independent predictive factor for RFS in GIST when taking into account the up-dated classification of TR. R1 resection may be considered a reasonable alternative to avoid major functional sequelae and should not lead to reoperation.

Impact of Tumor Size and Management on Survival in Small Gastric Gastrointestinal Stromal Tumors

BACKGROUND

Society guidelines remain inconsistent on the role of endoscopic and radiographic surveillance as an alternative to surgical resection of small gastric gastrointestinal stromal tumors (GISTs). Herein, we aimed to assess survival among patients with gastric GISTs undergoing observation versus surgical resection, stratified by tumor size.

METHODS

The National Cancer Database (NCDB) was queried for gastric GISTs < 2 cm diagnosed from 2010-2017. Patients were stratified by management strategy-observation vs surgical resection. The primary outcome, overall survival (OS), was examined with Kaplan-Meier and multivariable Cox proportional hazard methods. Subgroup analyses were conducted on tumors < 1 cm and 1-2 cm in size.

RESULTS

Altogether, 1208 patients were identified: 439 (36.3%) undergoing observation and 769 (63.7%) receiving surgical resection. In the overall cohort, patients undergoing surgical resection demonstrated improved survival (93.6 vs. 88.8% 5-year OS, p=0.02). In multivariable analysis, upfront surgical resection was not associated with a reduction in mortality; however, there was a significant interaction with tumor size. For patients with tumors < 1 cm, there was no difference in survival based on management strategy. However, resection of tumors 1-2 cm was associated with improved survival relative to surveillance.

CONCLUSIONS

While surgical resection and surveillance were associated with similar survival for patients with gastric GISTs < 1 cm, this NCDB analysis suggests that patients with tumor size ≥ 1 cm may benefit from upfront surgical resection. Prospective studies comparing these two approaches and their impact on recurrence-free and disease-specific survival are needed to better align consensus guidelines and recommendations.

Endoscopic full-thickness resection, indication, methods and perspectives

Minimally invasive surgery has emerged as the dominant theme of modern surgery, in which endoscopic surgery plays a key role. The technique of endoscopic surgery has evolved continuously with extensive research, improving the treatment modalities as well as expanding the indications for its use. As an active perforation endoscopic technique, endoscopic full-thickness resection (EFTR) is mainly used in the treatment of submucosal tumors (SMTs) of the gastrointestinal tract. With decades of evolution, EFTR has gradually developed into a mature endoscopic operation. Based on clinical experience and current research, indications, techniques, clinical outcomes and future perspectives for EFTR are discussed in this paper. We performed a bibliometric study on EFTR literature and showed robust data through a brief meta-analysis on the topic.

The Feasibility and Safety of the Clip-and-Snare Method with a Prelooping Technique for Gastric Submucosal Tumors Removal: A Single-Center Experience (with Video)

AIM

This study compared the efficacy and safety of endoscopic submucosal dissection (ESD) combined with clip-and-snare method and a prelooping technique (CSM-PLT) with ESD alone for the treatment of gastric submucosal tumors (gSMTs).

METHODS

We retrospectively enrolled a matched group of 86 patients who received ESD combined with CSM-PLT or ESD alone from July 2010 to July 2020. The primary outcomes included complete resection, en bloc resection, and R0 resection.

RESULTS

Eighty-six patients with gSMTs were enrolled in ESD combined with CSM-PLT group and ESD group, respectively. There were no significant differences in gender, age, tumor size, tumor location, and tumor origin between the two groups. The complete resection, en bloc resection, and R0 resection rates were comparable between two groups (P=1, P=0.31, and P=0.25, respectively). There were no significant differences in terms of hospital stays, hospitalization cost, postoperative complications, and residual rate (P=0.42, P=0.74, P=0.65, and P=1, respectively) between the two groups. However, the ESD combined with CSM-PLT was associated with a shorter procedure duration and fewer intraoperative complications (P < 0.001 and P=0.024, respectively). In addition, the incidence of intraoperative bleeding in ESD combined with CSM-PLT group was significantly lower than that in ESD group (P=0.04).

CONCLUSION

Both ESD combined with CSM-PLT and ESD were effective and safe modalities for the treatment of gSMTs. However, ESD combined with CSM-PLT was associated with a shorter procedure duration and fewer intraoperative complications.

A Case Report of Multiple Gastrointestinal Stromal Tumors: Imaging Findings, Surgical Approach, and Review of the Literature

Introduction

Multiple gastrointestinal stromal tumors (GISTs) are rare tumors. Differential diagnosis between metastatic and multiple GISTs represents a challenge for a proper workup, prediction prognosis, and therapeutic strategy.

Case presentation

We present the case of 67-year-old man with computed tomography (CT) evidence of multiple exophytic lesions in the abdomen, reaching diameters ranging from 1 to 9 cm, without any signs of organs infiltration, and resulting positive at 18F-FDG-PET/CT. Laparoscopic biopsy revealed multiple GISTs, and surgical resection by using an open approach was performed to achieve radicality. Moreover, an extensive review of the current literature was performed.

Results

Small GISTs (<5 cm) can be treated by the laparoscopic approach, while in the case of large GISTs (>5 cm), tumor location and size should be taken into account to reach the stage of radical surgery avoiding tumor rupture. For metastatic GISTs, Imatinib represents the first choice of treatment, and surgery should be considered only in a few selected cases when all lesions are resectable.

Conclusion

Sporadic multiple GISTs are a rare event, imaging findings are not specific for GISTs, and biopsy requires a secure diagnosis and proper management. In the case of large lesions, with a high risk of vessels injury, laparotomy excision should be considered to achieve radicality and to avoid tumor rupture.

A modified endoscopic full thickness resection for gastric subepithelial tumors from muscularis propria layer: Novel method

BACKGROUND AND AIM

The removal of subepithelial tumors (SETs) is challenging, particularly in tumors originating from the muscularis propria (MP) in the upper gastrointestinal (GI) tract, owing to the high risk of perforation. We developed mechanical spray lumpectomy (MSL), which is a novel method to safely and easily remove the tumor. This study aimed to evaluate the feasibility and safety of MSL as a novel endoscopic treatment for gastric subepithelial lesions.

METHODS

We performed MSL in a total of 13 patients with upper GI SETs originating from the MP layer. First, mucosectomy was performed using a conventional snare. Repeated injections were performed towards the subserosal layer. After injection, the lesion was mechanically pushed to separate the MP layer using an endoscopic cap. Finally, the mucosa, submucosa, and MP layer with SETs were completely dissected using the spray coagulation mode, and the remaining defect was closed with clipping.

RESULTS

All tumors were completely resected. The mean procedure time was 84.38 ± 41.73 min. There were four leiomyomas, six GI stromal tumors, one mucosa-associated lymphoid tissue lymphoma, and two ectopic pancreases. Although small perforation occurred in only one case, the defect was successfully closed using hemostatic clipping. Moreover, no serious complications related to MSL were encountered during or after the procedure. No residual lesion or recurrence was observed during the follow-up period.

CONCLUSIONS

Mechanical spray lumpectomy can be a novel method that provides a safe and minimally invasive endoscopic treatment for upper GI SETs originating from the MP layer.

Transvaginal Resection of a Rectal Gastrointestinal Stromal Tumor: A Case Report

Gastrointestinal stromal tumors (GISTs) are a type of mesenchymal tumors. They are rare in rectum. This location is a surgical challenge due to the high morbidity after aggressive surgeries. We present the case of an 81-year-old female with a high-grade GIST treated with transvaginal excision and adjunctive therapy with imatinib. The postoperative period was uneventful without anal dysfunction. Within the types of surgical treatment available, transvaginal excision is an acceptable procedure in lesions located in the rectovaginal region.

A case of KIT negative extra-gastrointestinal stromal tumor arising in the greater omentum with predominant cystic formation

We report a rare case of KIT-negative extra-gastrointestinal stromal tumor, in a 40-year-old woman. Contrast-enhanced computed tomography and magnetic resonance imaging revealed a >15-cm mass of multiple cystic lesions in the greater omentum. Histopathological findings after surgery showed a sheet-like growth of stellate tumor cells from epithelial cells, cystic degeneration, and mucus-like stroma. Immunohistochemistry was positive for discovered on GIST-1 (DOG1) but negative for CD117 (c-kit).

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.

Integrating Anatomical, Molecular and Clinical Risk Factors in Gastrointestinal Stromal Tumor of the Stomach

BACKGROUND

Adjuvant imatinib for 3 years is recommended to patients with high-risk gastrointestinal stromal tumor (GIST). Risk stratification is inaccurate, and risk assessments are further complicated by the increased use of neoadjuvant treatment. Anatomical criteria for prognostication have not been investigated.

METHODS

Clinical, molecular, and anatomical variables were retrospectively studied in a population-based cohort of 295 patients with gastric GIST resected between 2000 and 2018. Gastric subsite was divided into the upper, middle, and lower thirds. Growth pattern was classified as luminal, exophytic, or transmural based on imaging and surgical reports.

RESULTS

Of 113 tumors in the upper third of the stomach, 103 (91.2%) were KIT mutated, 7 (6.2%) were PDGFRA mutated, and 104 (92.0%) harbored genotypes sensitive to imatinib. Transmural tumors were strongly associated with a high mitotic index. Five-year recurrence-free survival (RFS) was 71% for patients with transmural tumors versus 96% with luminal or exophytic tumors (hazard ratio [HR] 8.45, 95% confidence interval [CI] 3.69-19.36; p < 0.001), and, in high-risk patients, 5-year RFS was 46% for patients with transmural tumors versus 83% with luminal or exophytic tumors (HR 4.47, 95% CI 1.71-11.66; p = 0.001). Among 134 patients with tumors > 5 cm, there were 29 recurrences. Only five patients with exophytic or luminal tumors had recurrent disease, of whom four had tumor rupture. Five-year RFS for patients with exophytic/luminal tumors >5 cm without rupture was 98%.

CONCLUSIONS

In the upper third, over 90% of tumors were sensitive to imatinib. Patients with exophytic or luminal tumors without rupture, irrespective of size, had an excellent prognosis and may not benefit from adjuvant therapy.

Robot-assisted resection of GIST in the proximal jejunum

Gastrointestinal stromal tumors (GISTs) are rare. Although most commonly found in the stomach, GISTs in the jejunum are among the rarest subtypes. A 46-year-old woman presented to the surgical department with proximal jejunal mass found in the examinations after abdominal pain and melena. Computed tomography imaging showed a 2.3 cm sized well-defined heterogenous enhancing mass in the proximal jejunum, and GIST was strongly suspected. The jejunal mass was identified 5 cm below the ligament of Treitz intraoperatively. She underwent robotic-assisted jejunal resection with intracorporeal robot-sewn anastomosis. The patient's postoperative course was uneventful, and she was discharged on the seventh postoperative day. A robotic approach for GIST in the proximal jejunum is a safe and feasible procedure with good surgical outcomes.

Gastrointestinal stromal tumour of stomach: Feasibility of laparoscopic resection in large lesions and its long-term outcomes

Background:

Gastric gastrointestinal stromal tumours (GISTs) are rare neoplasms that require excision for cure. Although the feasibility of laparoscopic resection of smaller gastric GIST has been established, the feasibility and long-term efficacy of these techniques are unclear in larger lesions. This study is done to assess the feasibility of the laparoscopic resection of gastric GISTs and their long-term outcomes.

Methods:

Patients who underwent laparoscopic resection of gastric GISTs were identified in a prospectively collected database. Outcome measures included patient demographics, operative findings, morbidity and histopathologic characteristics of the tumour. Patient and tumour characteristics were analysed to identify risk factors for tumour recurrence.

Results:

There were 42 patients with a mean age of 56.7 years and had a mean tumour size was 4.5 ± 2.7 cm. Laparoscopic wedge resection was the most common procedure done. There were no major perioperative complications or mortalities. All lesions had negative resection margins. At a mean follow-up of 48 months, 36/39 (92.3%) patients were disease free and 3/39 (7.6%) had progressive disease. Univariate analysis showed that there was a statistically significant association of disease progression with tumour size, high mitotic index, tumour ulceration and tumour necrosis. The presence of >10 mitotic figures/50 high-power field was an independent predictor of disease progression.

Conclusion:

Our study establishes laparoscopic resection is feasible and safe in treating gastric GISTs for tumours >5 cm size. The long-term disease-free survival in our study shows acceptable oncological results in comparison to historical open resections.

Jejunal GIST: Hunting down an unusual cause of gastrointestinal bleed using double balloon enteroscopy. A case report

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Bleeding jejunal GIST is very rare with only a handful of published case reports.

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Double-balloon enteroscopy and capsule endoscopy can be used to diagnose bleeding small intestine GIST.

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Occult small bowel bleeding can go undetected for years.

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Age is one of the determining factors for the type of small bowel pathology detected.

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Surgical resection remains the mainstay treatment for GIST.

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Laparoscopic surgery offers similar oncologic outcomes as an open surgery.

Introduction

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal neoplasms of the alimentary tract but accounts for only 0.1–3% of all gastrointestinal neoplasms. The most common presentation of GISTs is acute or chronic gastrointestinal bleeding, in which the patient presents with symptomatic anaemia.

Presentation of case

With that in mind, we describe a 66-year-old man who presented with recurrent episodes of obscure gastrointestinal bleeding for two years. Video capsule endoscopy (VCE) showed several small telangiectasias in the proximal small bowel. Oral route double-balloon enteroscopy (DBE) revealed abnormal mucosa 165 cm from incisor with central ulceration and vascular component. He subsequently underwent surgical excision. The histopathological report confirmed the diagnosis of GIST arising from the jejunum. During his clinic follow up, he remains symptom-free with no evidence of recurrence.

Discussion

The diagnosis of bleeding small intestine GISTs can be challenging as these are inaccessible by conventional endoscopy. Imaging modalities such as double-balloon enteroscopy, capsule endoscopy, CT angiography, intravenous contrast-enhanced multidetector row CT (MDCT) and magnetic resonance enterography (MRE) have been used to assist in the diagnosis of bleeding small intestine GISTs. The mainstay of management for small intestine GIST is complete surgical excision.

Conclusion

Bleeding jejunal GIST is very rare and only a handful of case reports have been published. The mainstay of management for small intestine GIST is complete surgical excision. It is essential to obtain a complete excision of localised disease and avoiding tumour spillage in order to reduce the risk of local recurrence and metastatic spread of GISTs.