Surgical treatment of gastrointestinal stromal tumors of the stomach: current status and future perspective

The relationship between Ki-67 expression and imaging signs and pathological features in GISTs

Introduction

To investigate the correlations between the Ki-67 index and plain-scan computerized tomography (CT) signs and pathological features of gastrointestinal stromal tumor (GIST) tissue.

Materials and methods

Data from 186 patients with GIST diagnosed by pathology and immunohistochemistry (IHC) in Peking University First Hospital from May 2016 to May 2022 were analyzed. The patients were divided into two groups: Ki-67 ≤5% and >5%. Correlation analysis, univariate and multivariate Logistic regression analysis were used to explore the correlations between CT signs, pathological features, and Ki-67 expression.

Results

Univariate indicators correlated with the Ki-67 index were mitotic count, pathological grade, tumor hemorrhage, tumor necrosis, tumor size, and tumor density. Multivariate Logistic regression indicated that the mitotic count [odds ratio (OR) 10.222, 95% confidence interval (CI) 4.312–31.039], pathological grade (OR 2.139, 95% CI 1.397–3.350), and tumor size (OR 1.096, 95% CI 1.020–1.190) were independently associated with the Ki-67 expression level. The concordance indexes (C-index) for the pathological features and CT signs models were 0.876 (95% CI 0.822–0.929) and 0.697 (95% CI 0.620–0.774), respectively, with positive predictive values of 93.62% and 58.11% and negative predictive values of 81.29% and 75.89%, respectively. After internal verification by the Bootstrap method, the fitting degree of the pathological features model was found to be better than that of the CT signs model.

Conclusion

Mitotic count, pathological risk grading, and tumor size are independent risk factors correlating with high Ki-67 index. These results indicate that the Ki-67 index reflects tumor malignancy and can predict recurrence and metastasis of GIST.

A Case of Accidentally Found Gastrointestinal Stromal Tumor in a 57-Year-Old Candidate of Gastric Bypass Surgery

INTRODUCTION

GIST tumors are the most common mesenchymal tumors in the alimentary tract but are rather rare compared to other GI tract tumors and are usually found incidentally. Studies about cases of GIST tumor in bariatric surgery are scarce and there is no specific guideline for treatment. Most of previous cases were managed by sleeve gastrectomy due to their location which were usually in the body and greater curvature.

METHODS

This patient had a GIST on lesser curvature and therefore underwent laparoscopic Roux-en-Y bypass. The follow-up was done with imaging studies and CT scan since the location of the tumor was no longer accessible to endoscopy after the gastric bypass.

RESULTS

The post-operative course was uneventful and after 2 years the patient is still in good health and had no other complications. The patient has been followed up by imaging studies.

DISCUSSION

There are pros and cons to this compared with sleeve gastrectomy. The most important advantage for this approach is that we have the stomach preserved; thus, our operation has the reversibility potential in case of any complication which requires revision operations. However, on the flip side, the limitation of such intervention is that we are not able to use the EGD to monitor and follow up our patient. Based on the relevant literature, for following up and monitoring the postoperative condition of these patients with relatively small GISTs, imaging studies specially abdominal computed tomography scan (CT scan) would be highly beneficial. It is also worth of mentioning that performing a EGD before a bariatric surgery, which is well noted in IFSO position statements and is well explained and discussed in other literature, had a major role in diagnosing this patient's GIST tumor and is proved to be beneficial and essential, once again.

Laparoscopic resectional oesophago-gastroplasty: a novel technique for minimally invasive treatment of large high gastric lesser curve GIST involving gastroesophageal junction

A paramount factor in selecting the operative approach for gastric gastrointestinal stromal tumours (GIST) is tumour location. Tumours located high along the lesser curve of the stomach pose a challenge in laparoscopic resection. A 56-year-old lady presented with per rectal bleeding and loss of weight. Endoscopic and radiological investigations revealed a large gastric GIST located over the lesser curve with proximal margin <1 cm from the gastroesophageal junction (GEJ). We present the steps of a novel technique for laparoscopic resectional oesophago-gastroplasty to resect large high gastric lesser curve GIST involving the GEJ.

Ki-67 labelling index is related to the risk classification and prognosis of gastrointestinal stromal tumours: a retrospective study

BACKGROUND AND AIMS

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the digestive tract with malignant potential. The current risk classification standard is unable to accurately evaluate the invasiveness and clinical outcomes of GISTs. Ki-67 labelling index (LI) may be an effective indicator in assessing tumour invasiveness and prognosis, however, its exact value in GISTs is still uncertain. The aims of our study were to evaluate the correlation of the Ki-67 LI and clinicopathological features of GISTs and to assess the potential value of the Ki-67 LI in GISTs classification and prognosis.

METHODS

The clinical, pathological and prognostic data were collected and analysed to identify the independent influential factors of GISTs risk stratification and the predictors of GISTs prognosis.

RESULTS

The Ki-67 LI was significantly associated with the clinicopathological features of tumour progression (P<0.05). It was an independent influential factor of GISTs risk classification (odds ratio: 1.322; 95% confidence interval: 1.031-1.696) (P=0.028), and the area under the curve (AUC) value of the Ki-67 LI on the discrimination ability of GISTs risk stratification was 0.906 (P<0.001). The optimal cutoff value of the Ki-67 LI was 6% (sensitivity of 87.5% and specificity of 76.2%), and patients with Ki-67 LI≥6% exhibited significantly poorer progression-free survival (PFS) than those with Ki-67 LI<6% (P<0.001). The AUC value of the Ki-67 LI for predicting PFS in postoperative patients was 0.813 (P=0.03).

CONCLUSIONS

The Ki-67 LI has appreciated value to predict the risk grade and prognosis of GISTs. Patients with Ki-67 LI≥6% are prone to recurrence and metastasis after operation and may need a close follow-up.

Comprehensive review into the challenges of gastrointestinal tumors in the Gulf and Levant countries

Although gastrointestinal stromal tumors (GISTs) are rare, with an incidence of 1/100000 per year, they are the most common sarcomas in the peritoneal cavity. Despite considerable progress in the diagnosis and treatment of GIST, about half of all patients are estimated to experience recurrence. With only two drugs, sunitinib and regorafenib, approved by the Food and Drug Administration, selecting treatment options after imatinib failure and coordinating multidisciplinary care remain challenging. In addition, physicians across the Middle East face some additional and unique challenges such as lack of published local data from clinical trials, national disease registries and regional scientific research, limited access to treatment, lack of standardization of care, and limited access to mutational analysis. Although global guidelines set a framework for the management of GIST, there are no standard local guidelines to guide clinical practice in a resource-limited environment. Therefore, a group of 11 experienced medical oncologists from across the Gulf and Levant region, part of the Rare Tumors Gastrointestinal Group, met over a period of one year to conduct a narrative review of the management of GIST and to describe regional challenges and gaps in patient management as an essential step to proposing local clinical practice recommendations.

Safety and efficacy of magnetic anchoring electrode-assisted irreversible electroporation for gastric tissue ablation

BACKGROUND

Irreversible electroporation (IRE) is an emerging tissue ablation technique, which is safe for sites where thermal-basis techniques are not suitable. The aim of this study is to evaluate the safety and efficacy of magnetic anchoring electrode (MAE)-assisted IRE for normal gastric tissue ablation in a rabbit model.

METHODS

IRE (500 V, 100 μs, 99 pulses, 1 Hz) of the gastric wall was performed in 24 adult New Zealand rabbits with a novel catheter-mounted MAE with fluoroscopy and a surgical approach. Procedure time, procedure-related bleeding, perforation, and other complications were recorded. Animals were sacrificed at 30 min, 1 day, 3 days, 7 days, 14 days, and 28 days post-IRE. The stomach was removed en bloc, and the diameter of each lesion was measured. Histopathological analyses by Hematoxylin-Eosin (H&E), masson trichrome, alpha-smooth muscle action (α-SMA), and terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) were performed.

RESULTS

Gastric tissue ablation with MAE-assisted IRE was successfully performed without any interruption. No perforation or bleeding was observed during IRE or throughout the follow-up period. A demarcated hemorrhage was found in the ablated area upon gross examination. H&E staining showed complete cell death with inflammatory infiltration, edema, and hemorrhaging. TUNEL presented diffuse positive cells in the ablated area. The tissue scaffold was well preserved without damage as indicated by Masson trichrome staining. Ulceration was observed starting from 3 days post-IRE. The mucosal layer was gradually recovered and regenerated within 14-28 days. No other complication was observed post-IRE.

CONCLUSIONS

MAE-assisted IRE is safe and effective for normal gastric tissue ablation and the gastric wall recovered in 14-28 days post-IRE.

Laparoendoscopic Transgastric Resection of Prepyloric Gastrointestinal Stromal Tumor

This case report describes an 83-year-old woman with multiple comorbidities who presented with melena and coffee-ground emesis with diagnostic studies evident for a large prepyloric gastrointestinal stromal tumor. She underwent combined laparoendoscopic transgastric resection surgery for the tumor, performed by a team of gastroenterologist and thoracic surgeon with a successful outcome. The case and videos in this report provide a descriptive demonstration of the steps leading up to the surgical intervention followed by a step-by-step illustration of the combined surgical technique, thus highlighting the importance of multidisciplinary approach for optimal treatment of prepyloric gastrointestinal stromal tumor.

Laparoscopic Endoscopic Cooperative Surgery for Gastrointestinal Stromal Tumors

With the development of laparoscopy and digestive endoscopy, multiple laparoscopic and endoscopic cooperative surgeries (LECSs) for gastrointestinal stromal tumors have recently been developed. Classic LECS has been confirmed as a feasible and safe treatment procedure for gastrointestinal stromal tumors with regard to both short-term surgical and long-term oncological outcomes; however, classic LECS has the potential risk of gastric contents or tumor cells spilling into the abdominal cavity because the gastric wall has to be opened during the procedure. Various modified LECS techniques have aimed at further minimizing invasiveness, such as the full-thickness resection method using the nonexposure technique (combination of laparoscopic and endoscopic approaches to neoplasia with a nonexposure technique), nonexposed endoscopic wall-inversion surgery, and closed LECS. This review describes and summarizes the current LECS for gastrointestinal tumor.