Definition and clinical significance of tumour rupture in gastrointestinal stromal tumours of the small intestine

Next questions on gastrointestinal stromal tumors: unresolved challenges and future directions

PURPOSE OF REVIEW

Despite remarkable progress in the management of gastrointestinal stromal tumors (GISTs), critical challenges persist. Key aspects such as risk stratification, the optimal duration of adjuvant therapy, and strategies to enhance the efficacy of first-line treatment remain subjects of ongoing debate. This review explores emerging concepts and innovative approaches aimed at refining patient selection and optimizing therapeutic decision-making to further improve clinical outcomes.

RECENT FINDINGS

Molecular and genomic parameters have the potential to enhance traditional risk models, enabling more precise stratification of high-risk patients. Innovations in artificial intelligence and liquid biopsy are emerging as powerful tools for refining predictions of recurrence and treatment response. Meanwhile, the definition and prognostic significance of tumor rupture remain pivotal challenges that influence both risk assessment and adjuvant therapy decisions. Furthermore, transcriptomic and multiomic analyses have unveiled distinct GIST subtypes with significant prognostic and therapeutic implications, paving the way for more tailored treatment strategies.

SUMMARY

Integrating molecular features into clinical decision making may refine risk assessment and personalize the treatment in patients with GIST. Future research should focus on validating these tools and redefine clinical trial designs to accelerate drug development for this rare disease.

Impact of Mutation Profile on Outcomes of Neoadjuvant Therapy in GIST

BACKGROUND

Neoadjuvant imatinib therapy plays a crucial role in the management of gastrointestinal stromal tumors (GISTs), but its impact across various mutational profiles remains uncertain.

OBJECTIVE

The aim of this study is to describe the clinicopathological features and to assess the response and surgical outcomes of neoadjuvant imatinib in GIST patients exhibiting diverse mutational profiles.

METHODS

We conducted a retrospective study, extracting data from the Dutch GIST Registry, including patients treated with neoadjuvant imatinib. Response rate was the primary outcome, and secondary outcomes were the time on neoadjuvant treatment and resection margins (R0 vs. R1/R2), respectively.

RESULTS

Between 2009 and 2021, 326 patients were treated with neoadjuvant imatinib, of which 264 (80.9%) underwent resection. A total of 197 (74.6%) of them had a KIT-exon 11 mutation, 19 (7.3%) had other KIT mutations, 10 (3.8%) had PDGFRA D842 mutations, 21 (6.8%) had other PDGFRA mutations, 2 (0.7%) had NTRK mutation, 1 (0.4%) had an SDH mutation, and 17 (6.4%) had WT GISTs. Patients with KIT-exon 11 mutations demonstrated a higher rate of partial response to imatinib (60.5% vs. 33.3%; p = 0.00). A positive resection margin (R1 or R2) was observed in 14 (21.2%) patients with a non-KIT exon 11 mutations and in 11 (5.5%) patients with a KIT-exon 11 mutation (p = 0.00). Moreover, non-KIT exon 11 mutation patients had a shorter median duration of neoadjuvant therapy (5.3 months, range 0.5-21.0) compared to patients with a KIT exon 11 mutation (8.8 months, range 0.2-31.3; p < 0.001).

CONCLUSIONS

Our study highlights the variability in treatment response associated with different GIST mutational profiles. Patients with a KIT-exon-11 mutation tended to respond more favorably to neoadjuvant imatinib in terms of partial response and surgical outcomes.

Clinical importance of tumor rupture in gastrointestinal stromal tumor

Risk factors of gastrointestinal stromal tumors (GISTs) include tumor size, location, mitosis, and tumor rupture. Although the first three are commonly recognized as independent prognostic factors, tumor rupture is not a consistent finding. Indeed, tumor rupture may be subjectively diagnosed and is rarely observed. Moreover, the criteria used for diagnosis differ among oncologists, which may result in inconsistent outcomes. Based on these conditions, a universal definition of tumor rupture was proposed in 2019 and consists of six scenarios: tumor fracture, blood-stained ascites, gastrointestinal perforation at the tumor site, histologically proven invasion, piecemeal resection, and open incisional biopsy. Although the definition is considered appropriate for selection of GISTs with worse prognostic outcomes, each scenario lacks a high level of evidence and there is yet no consensus for some, including histological invasion and incisional biopsy. It may be, however, important to have common criteria for clinical decision-making, which may facilitate reliability, external validity, and comparability of clinical studies in rare GISTs. After the definition, several retrospective reports indicated that even with adjuvant therapy, tumor rupture was associated with high recurrence rates and poor prognostic outcomes. The prognosis of patients with ruptured GISTs is improved by 5-year adjuvant therapy compared with 3-year therapy. Nevertheless, the universal definition requires further evidence, and prospective clinical studies based on the definition are warranted.

Gastrointestinal Stromal Tumors (GISTs) in Pediatric Patients: A Case Report and Literature Review

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms that primarily affect adults, with pediatric cases constituting only 0.5-2.7% of the total. Pediatric GISTs present unique clinical, genetic, and pathological features that distinguish them from adult cases. This literature review aims to elucidate these differences, emphasizing diagnostic and therapeutic challenges. We discuss the resistance of pediatric GISTs to conventional chemotherapy and highlight the importance of surgical intervention, especially in emergency situations involving intra-abdominal bleeding. The review also explores the molecular characteristics of pediatric GISTs, including rare mutations such as quadruple-negative wild-type GIST with an FGF3 gene gain mutation. To illustrate these points, we conclude with a case from our clinic involving a 15-year-old female with multiple CD117-positive gastric GISTs and a quadruple-negative wild-type genetic profile who required urgent surgical intervention following a failed tumor embolization. This case underscores the critical need for early diagnosis and individualized therapeutic strategies combining oncologic and surgical care to improve outcomes in pediatric GIST patients.

Ruptured Duodenal GIST in a Young Female - A Rare Presentation and Comprehensive Review

Gastrointestinal stromal tumors (GISTs) are uncommon mesenchymal neoplasms primarily found in the gastrointestinal (GI) tract. While they typically occur in older adults, GISTs can manifest in individuals of any age. This publication paper presents a case study of a rare occurrence: a spontaneously ruptured duodenal GIST in a young female. Through an in-depth review of the literature, we aim to provide insights into the clinical presentation, diagnostic challenges, management strategies, and long-term outcomes associated with this unique clinical scenario.

Survival of patients with ruptured gastrointestinal stromal tumour treated with adjuvant imatinib in a randomised trial

BACKGROUND

Patients with ruptured gastrointestinal stromal tumour (GIST) have poor prognosis. Little information is available about how adjuvant imatinib influences survival.

METHODS

We explored recurrence-free survival (RFS) and overall survival (OS) of patients with ruptured GIST who participated in a randomised trial (SSG XVIII/AIO), where 400 patients with high-risk GIST were allocated to adjuvant imatinib for either 1 year or 3 years after surgery. Of the 358 patients with confirmed localised GIST, 73 (20%) had rupture reported. The ruptures were classified retrospectively using the Oslo criteria.

RESULTS

Most ruptures were major, four reported ruptures were reclassified unruptured. The 69 patients with rupture had inferior RFS and OS compared with 289 patients with unruptured GIST (10-year RFS 21% vs. 55%, OS 59% vs. 78%, respectively). Three-year adjuvant imatinib did not significantly improve RFS or OS of the patients with rupture compared with 1-year treatment, but in the largest mutational subset with KIT exon 11 deletion/indel mutation OS was higher in the 3-year group than in the 1-year group (10-year OS 94% vs. 54%).

CONCLUSIONS

About one-fifth of ruptured GISTs treated with adjuvant imatinib did not recur during the first decade of follow-up. Relatively high OS rates were achieved despite rupture.

CLINICAL TRIAL REGISTRATION

NCT00116935.

Endoscopic full-thickness resection for gastric submucosal tumors: Japanese multicenter prospective study

OBJECTIVES

Early gastric cancer endoscopic resection (ER) is prominent in Japan. However, evidence regarding ER of gastric submucosal tumors (SMT) is limited. This prospective multicenter phase II study investigated the efficacy and safety of endoscopic full-thickness resection (EFTR) for gastric SMT.

METHODS

Endoscopic full-thickness resection indication for gastric SMT was 11-30 mm, histologically proven or clinically suspicious (irregular margin, increasing size, or internal heterogeneity) gastrointestinal stromal tumors (GIST), with no ulceration and intraluminal growth type. The primary end-point was the complete ER (ER0) rate, with a sample size of 42.

RESULTS

We enrolled 46 patients with 46 lesions between September 2020 and May 2023 at seven Japanese institutions. The mean ± SD (range) endoscopic tumor size was 18.8 ± 4.5 (11-28) mm. The tumor resection and defect closure times were 54 ± 26 (22-125) min and 33 ± 28 (12-186) min, respectively. A 100% ER0 was achieved in all 46 patients. The EFTR procedure was accomplished in all patients without surgical intervention. One patient had delayed perforation and was managed endoscopically. GIST accounted for 76% (n = 35) of the cases. R0, R1, and RX rates were 33 (77%), 3 (6.5%), and 7 (15%), respectively.

CONCLUSION

Endoscopic full-thickness resection for gastric SMT of 11-30 mm is efficacious. It warrants further validation in a large-scale cohort study to determine the long-term outcome of this treatment for patients with gastric GIST.

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.

Classification of GIST and other benign gastric tumors based on minimally invasive surgical strategy

PURPOSE

Gastrointestinal mesenchymal tumors (GMTs) include malignant, intermediate malignancy, and benign lesions. The aim is to propose a new surgical classification to guide the intraoperative minimally invasive surgical strategy in case of non-malignant GMTs less than 5 cm.

METHODS

Primary endpoint is the creation of a classification regarding minimally invasive surgical technique for these tumors based on their gastric location. Secondary endpoint is to analyze the R0 rate and the postoperative morbidity and mortality rates. Tumors were classified in two groups based on their morphology (group A: exophytic, group B: transmural/intragastric). Each group is then divided based on the tumor location and consequently surgical technique used in subgroup: AI (whole stomach area) and AII (iuxta-cardial and pre-pyloric areas) both for the anterior and posterior gastric wall; BIa (greater curvature on the anterior and posterior wall), BIb (lesser curvature on the anterior wall); BII (iuxta-cardial and pre-pyloric area in the anterior and posterior wall, including the lesser curvature on the posterior wall).

RESULTS

Forty-two patients were classified and allocated in each subgroup: 17 in AI, 2 in AII, 5 in BIa, 3 in BIb, and 15 in BII. Two postoperative Clavien-Dindo I complications (4.8%, subgroup BIa and BIb) occurred. One patient (2.4%, subgroup AI) underwent reintervention due to R0 resection.

CONCLUSIONS

This classification proved to be able to classify gastric lesions based on their morphology, location, and surgical treatment, obtaining encouraging perioperative results. Further studies with wider sample of patients are required to draw definitive conclusions.

Re-appraisal of the universal definition of tumor rupture among patients with high-risk gastrointestinal stromal tumors

Aim

Tumor rupture has been indicated as a risk factor for recurrence of gastrointestinal stromal tumors (GISTs). The universal definition of tumor rupture was proposed. This study evaluated whether the universal definition was more accurate in identification of GISTs with high recurrent risk than subjective judgment.

Methods

The study included 507 patients with high-risk GISTs who underwent complete resection between December 2012 and December 2015. We conducted a questionnaire survey in participating institutes to re-diagnose tumor rupture based on the universal definition according to their surgical and pathological findings. We compared the clinical outcomes of tumor rupture based on the definition to those based on the surgeon's judgment and clarified the clinical importance of the rupture.

Results

Sixty-four patients were initially registered to have tumor rupture by surgeon's judgment, and it became 90 patients who had tumor rupture after reevaluation. Although there were significant differences in recurrence-free survival (RFS) between no rupture and rupture for both initial registration and reevaluation (p = 0.002, <0.001, respectively), a significant difference in overall survival was only observed after reevaluation (p = 0.011). Tumor rupture was significantly associated with large tumor size, mixed cell type in histology, R1 resection, frequent adjuvant therapy and recurrence, but not with location, mitosis, and genotype. Adjuvant therapy more than 3 years improved RFS of patients with tumor rupture.

Conclusion

This study suggested that tumor rupture based on the universal definition more accurately identified GISTs with poor prognostic outcomes than the subjective judgment.

Is Bleeding Gastrointestinal Stromal Tumor Associated With Higher Mortality and Morbidity?

Introduction Gastrointestinal stromal tumor (GIST) is the most common primary mesenchymal tumor of the gastrointestinal tract. The clinical presentation of GIST varies widely and ranges from being asymptomatic to being a life-threatening emergency in the form of gastrointestinal bleeding or bowel obstruction. Multiple prognostic factors have been identified for GIST, including, most importantly, larger tumor size (>5 cm), higher mitotic activity (>5 per 50 high-power fields), rupture of the mass, site of the mass, and personal history of GIST. Objective In this paper, we aim to study bleeding in gastrointestinal tumors as a predictor for morbidity and mortality and investigate possible factors influencing bleeding in GIST. Method A retrospective study design was used. Electronic medical records of 39 patients diagnosed with GIST in Prince Sultan Military Medical City in Riyadh between January 2015 and December 2020 were retrieved. Normal variables were presented as mean and standard deviation, while non-normal variables were presented as median and interquartile range. Student t-test or Mann-Whitney test was used to compare quantitative data when appropriate. The distribution of recurrence and survival was plotted with the Kaplan-Meier curve and compared between the two groups (bleeding and non-bleeding groups) with the log-rank test. Factors affecting recurrence and mortality were assessed using univariable Cox regression. Result A total of 39 cases of GIST tumors were included in this study. Patients were categorized according to the presentation into two groups: patients with no bleeding (n= 28) and those presented with bleeding (n= 11). The gender distribution was equal. The mean age was 58.14± 12.46 in patients with non-bleeding GIST and 58.18± 16.01 in patients with bleeding GIST. The most common location of GIST was the stomach (22 cases, 56%). Neither group had any significant differences regarding age (P-value = 0.993), gender (P-value = 0.648), tumor location (P-value = 0.057), size (P-value = 0.250), cluster of differentiation (CD) markers, histological types (P-value = 0.692), and shape (P-value = 0.079). There was no significant difference in recurrence between both groups (log-rank P = 0.972). There was no significant difference in survival between both groups (Log-rank P = 0.506). Conclusion We concluded that bleeding GIST was not a significant predictor for recurrence rate or higher mortality. This can help in the debate of whether bleeding GIST should be added as an independent factor in risk stratification. Despite that, further studies are needed to identify more variables that can add more accuracy to the pre-existing risk stratification systems.

A giant gastric stromal tumor with dizziness as the main complaint: A case report and literature review

INTRODUCTION

Small gastrointestinal stromal tumors (GISTs) are often asymptomatic. However, large tumors can cause symptoms like abdominal pain and GI bleeding. We experienced a unique case where a giant GIST was incidentally found by CT scanning during emergency treatment for dizziness.

PRESENTATION OF CASE

A 61-year-old man presented temporary dizziness after exercising three days ago before his admission. Enhanced CT scan of the abdomen and pelvis revealed a large circular mass in the right upper abdominal cavity, with a maximum cross-sectional size of approximately 132 mm × 155 mm. Biopsy and genetic testing confirmed the diagnosis of GIST. The patient underwent successful radical surgery and was discharged at 12th post-operative day without any complications. The patient now is taking imatinib as an adjuvant targeted therapy.

DISCUSSION

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive tract with diverse clinical presentations according to their sites and sizes. As in this case, the patient's primary complaint was dizziness, which is uncommon for GISTs. Initial workup, including three-dimensional rebuilding of the enhanced CT scanning and biopsy, was given before surgery. Finally, despite the tumor's large size and attachment to adjacent structures, R0 resection was accomplished without intraoperative rupture.

CONCLUSION

This case highlights the importance of healthcare providers vigilant in identifying GISTs with unusual symptoms in emergency situations. A systematic and comprehensive examination can be and should be performed to confirm diagnosis and determine the feasibility of R0 resection. By sharing this unique case, we aim to enhance the understanding of GIST and increase awareness among clinicians about their varied presentations.

Impact of tumour rupture risk on the oncological rationale for the surgical treatment choice of gastrointestinal stromal tumours

Tumour rupture of gastrointestinal stromal tumours (GISTs) has been considered to be a remarkable risk factor because of its unfavourable impact on the oncological outcome. Although tumour rupture has not yet been included in the current tumor-node-metastasis classification of GISTs as a prognostic factor, it may change the natural history of a low-risk GIST to a high-risk GIST. Originally, tumour rupture was defined as the spillage or fracture of a tumour into a body cavity, but recently, new definitions have been proposed. These definitions distinguished from the prognostic point of view between the major defects of tumour integrity, which are considered tumour rupture, and the minor defects of tumour integrity, which are not considered tumour rupture. Moreover, it has been demonstrated that the risk of disease recurrence in R1 patients is largely modulated by the presence of tumour rupture. Therefore, after excluding tumour rupture, R1 may not be an unfavourable prognostic factor for GISTs. Additionally, after the standard adjuvant treatment of imatinib for GIST with rupture, a high recurrence rate persists. This review highlights the prognostic value of tumour rupture in GISTs and emphasizes the need to carefully take into account and minimize the risk of tumour rupture when choosing surgical strategies for GISTs.

Surgical and Oncological Outcomes after Neoadjuvant Therapy for Non-Metastatic Gastric GISTs

Surgical resection with negative margins of non-metastatic gastric GISTs is considered the main therapeutic option in GISTs treatment. Neoadjuvant therapy with imatinib is associated with higher response rates in advanced GISTs. We reported 34 patients with non-metastatic gastric GISTs who underwent partial gastrectomy at the Oncology Center, Mansoura University, Egypt, after receiving a daily dose of 400 mg of imatinib as a neoadjuvant treatment in the period between October 2012 and January 2021. Twenty-two cases underwent open partial gastrectomy, and twelve cases had a laparoscopic partial gastrectomy. The median tumor size at diagnosis was 13.5 cm (range 9-26 cm) and the duration of neoadjuvant therapy was 10.91 months (range 4-12 months). Thirty-three patients had a partial response, while one patient showed progression of the disease on neoadjuvant treatment. Adjuvant therapy was conducted in 29 (85.3%) cases. Complications of neoadjuvant treatment were reported in seven cases in the form of gastritis, bleeding per rectum, fatigue, thrombocytopenia, neutropenia, and edema lower limbs. The disease-free survival (DFS) in this study was 34.53 months, and the overall survival (OS) was 37 months. Recurrence developed in two cases, gastric and peritoneal recurrence (25 and 48 months from the initial diagnosis, respectively). We have concluded that neoadjuvant treatment with imatinib for non-metastatic gastric GISTs is a safe and effective method for tumor downsizing and devitalization to allow minimally invasive and/or organ sparing surgery. Moreover, it decreases the risk of intraoperative tumor rupture and relapse, thus improving the oncological outcome of such tumors.

Analysis of risk factors and prognostic factors for gastrointestinal stromal tumors with gastrointestinal hemorrhage: Based on propensity score matching method

BACKGROUND

This study aimed to analyze the relationship between risk factors and prognosis of patients with gastrointestinal stromal tumor associated with gastrointestinal bleeding.

METHODS

According to whether there was gastrointestinal bleeding, 246 patients with gastrointestinal stromal tumors were divided into 2 groups. The clinicopathological baseline characteristics of the 2 groups of patients were balanced by propensity score matching, and the Kaplan-Meier method was used to draw the survival curve and analyze the overall survival of the 2 groups of patients. The receiver operating characteristic curve was drawn to evaluate the accuracy of Modified National Institutes of Health criteria and Armed Forces Institute of Pathology criteria in predicting the prognosis and postoperative recurrence of patients. Logistic regression analysis of risk factors affecting gastrointestinal stromal tumor with gastrointestinal bleeding before matching. Univariate and multivariate analyses of risk factors affecting the prognosis of patients with gastrointestinal stromal tumors after matching were performed using Cox regression models.

RESULTS

Before matching, the accuracy of Modified National Institutes of Health criteria in predicting postoperative survival status and recurrence was higher than that of Armed Forces Institute of Pathology criteria. Modified National Institutes of Health criteria and relapse were the risk factors for gastrointestinal stromal tumor with gastrointestinal bleeding independent risk factors (P < .05). After 1:1 matching, the general clinical data of patients with gastrointestinal bleeding group and nongastrointestinal bleeding group were balanced (P > .05). The results of matched survival analysis indicated that tumor location and gastrointestinal bleeding were independent risk factors for the prognosis of patients with gastrointestinal stromal tumors (P < .05). The results of subgroup analysis according to anatomical site showed that there was no significant difference between the gastrointestinal bleeding group and the nongastrointestinal bleeding group (P > .05). Survival analysis showed that patients with gastrointestinal stromal tumors with gastrointestinal bleeding had a worse prognosis, and the results were also applicable in different tumor anatomical locations and different Modified National Institutes of Health criteria.

CONCLUSION

Modified National Institutes of Health criteria and relapse are independent risk factors for gastrointestinal stromal tumors with gastrointestinal bleeding; gastrointestinal bleeding is associated with poor prognosis in patients with gastrointestinal stromal tumors, and patients with gastrointestinal stromal tumors with gastrointestinal bleeding have a worse prognosis.

Effectiveness and safety of endoscopic resection for duodenal gastrointestinal stromal tumors: A single center analysis

BACKGROUND

Endoscopic resection for duodenal gastrointestinal stromal tumors (GISTs) is still considered a great challenge with a high risk of complications, including perforation, bleeding, tumor rupture, and residual tumor.

AIM

To assess the effectiveness and safety of endoscopic resection for duodenal GISTs.

METHODS

Between January 2010 and January 2022, 11 patients with duodenal GISTs were treated with endoscopic resection. Data were extracted for the incidence of complete resection, bleeding, perforation, postoperative infection, recurrence, and distant metastasis.

RESULTS

The incidence of successful complete resection of duodenal GISTs was 100%. Three cases (27.3%) had suspected positive margins, and the other 8 cases (72.7%) had negative vertical and horizontal margins. Perforation occurred in all 11 patients. The success rate of perforation closure was 100%, while 1 patient (9.1%) had suspected delayed perforation. All bleeding during the procedure was managed by endoscopic methods. One case (9.1%) had delayed bleeding. Postoperative infection occurred in 6 patients (54.5%), including 1 who developed septic shock and 1 who developed a right iliac fossa abscess. All 11 patients recovered and were discharged. The mean hospital stay was 15.3 d. During the follow-up period (14-80 mo), duodenal stenosis occurred in 1 case (9.1%), and no local recurrence or distant metastasis were detected.

CONCLUSION

Endoscopic resection for duodenal GISTs appears to be an effective and safe minimally invasive treatment when performed by an experienced endoscopist.

Prognostic Nomogram for Gastrointestinal Stromal Tumors after Surgery Based on the SEER Database

We aimed to determine prognostic factors and develop an effective and practical nomogram for predicting cancer-specific survival in gastrointestinal stromal tumor (GIST) patients. Postoperative data were obtained from the SEER database (2000-2018). Patients were divided into training and validation cohorts at random (7 : 3). Prognostic factors were screened, and a prognostic nomogram was established using log-rank testing and Cox regression. We used DCA, ROC curves, C-index, and calibration curves to evaluate our model's predictive performance. The clinical value of the nomogram and the modified National Institute of Health (M-NIH) classification were compared using the NRI and IDI. The Kaplan-Meier method was applied to examine survival by risk group, and log-rank tests were applied to compare variations in survival curves. Independent prognostic risk factors associated with cancer-specific survival on multivariate Cox proportional hazards regression analysis were age, race, and tumor location, size, grade, and stage. Clinically relevant variables need to be considered in addition to statistically significant variables when developing prognostic models to aid clinical decision-making. We included two additional variables (mitotic rate and chemotherapy) when constructing the prognostic model. The C-index was 0.766 (95% confidence interval (CI): 0.737-0.794) in the training cohort and 0.795 (95% CI: 0.754-0.836) in the internal validation group suggesting robustness. The areas under the ROC curve for three-year and five-year survival were >0.700, indicating satisfactory discrimination. The calibration curves showed good agreement between the predictions of the nomogram and the actual results. The NRI (0.346 for 3-year and 0.265 for 5-year cancer-specific survival for patients with GIST (GSS) prediction; validation cohort: 0.356 for 3-year and 0.246 for 5-year GSS prediction) and IDI values (0.047 for 3-year and 0.060 for 5-year GSS prediction; validation cohort: 0.071 for 3-year and 0.084 for 5-year GSS prediction) suggested that the established nomogram performed significantly better than the M-NIH classification. The DCA indicated that the nomogram was clinically useful and had a high discriminative ability in identifying patients who were at high risk of poor outcomes. According to nomogram findings, patients were divided into three groups (high, moderate, and low risk), with significantly different prognoses in both cohorts. Our nomogram satisfactorily predicted survival in postsurgical GIST patients, which may assist clinicians to evaluate the postoperative status and guide subsequent treatments.

The Diagnosis of Small Gastrointestinal Subepithelial Lesions by Endoscopic Ultrasound-Guided Fine Needle Aspiration and Biopsy

Endoscopic ultrasonography (EUS) has been widely accepted in the diagnosis of all types of tumors, especially pancreatic tumors, lymph nodes, and subepithelial lesions (SELs). One reason is that the examination can provide a detailed observation, with tissue samples being immediately obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Many SELs are detected incidentally during endoscopic examinations without symptoms. Most SELs are mesenchymal tumors originating from the fourth layer, such as gastrointestinal stromal tumors (GISTs), leiomyomas, and schwannomas. GISTs are potentially malignant. Surgical treatment is recommended for localized GISTs of ≥20 mm. However, the indications for the diagnosis and follow-up of GISTs of <20 mm in size are controversial. There are several reports on the rapid progression or metastasis of small GISTs. Therefore, it is important to determine whether a SEL is a GIST or not. The main diagnostic method is EUS-FNA. Recently, endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) using a new biopsy needle has been reported to obtain larger tissue samples. Additionally, various biopsy methods have been reported to have a high diagnostic rate for small GISTs. In local gastric SELs, regardless of the tumor size, EUS can be performed first; then, EUS-FNA/B or various biopsy methods can be used to obtain tissue samples for decision-making in relation to therapy and the follow-up period.

Impact of preoperative tumor rupture timing on gastrointestinal stromal tumor prognosis: a retrospective multicentric cohort study

BACKGROUND

A gastrointestinal stromal tumor rupture entails a high risk of recurrence even after curative surgery. However, the definition of rupture is unclear, and the question of whether patients with a minor rupture should be treated with adjuvant imatinib remains controversial.

METHODS

The present, retrospective, multicentric study enrolled 57 patients with gastrointestinal stromal tumor with a minor/major tumor rupture, of whom 46 were finally found to be eligible for analysis. Tumor ruptures were subclassified by their degree, timing and cause. Multivariate analysis was performed to identify the risk factors of all types of recurrence as well as of peritoneal recurrence only.

RESULTS

The study cohort included minor (n = 24), intraoperative (n = 19) and iatrogenic (n = 20) ruptures besides the typical types (major, preoperative and spontaneous). All intraoperative ruptures were iatrogenic. In total, 27 patients (58.7%) had a recurrence in the peritoneum (n = 17) and/or the liver (n = 13) during a median follow-up period of 5.8 years, but no recurrence was observed in patients with tumor rupture as a single, high-risk factor. Multivariate analysis found the timing of tumor rupture to be an independent risk factor of poor recurrence-free survival (hazard ratio: 2.37; 95% confidence interval: 1.02-5.49; P = 0.045).

CONCLUSIONS

Preoperative tumor rupture in patients with a ruptured gastrointestinal stromal tumor was associated with poor recurrence-free survival. Our results suggested that a distinction should be made between preoperative and intraoperative tumor ruptures when considering the indications for adjuvant imatinib therapy for gastrointestinal stromal tumor patients with tumor rupture as a single, high-risk factor of recurrence.

Clinicopathological characteristics and prognosis of gastrointestinal stromal tumors containing air-fluid levels

An air-fluid level within a gastrointestinal stromal tumor (GIST) is unusual and indicates the presence of a fistula within the lumen of the GI tract. Until recently, the optimal management of such patients was not clear-cut. This retrospective study investigated the clinicopathological characteristics, surgical procedures, pre-and post-operative management, and prognosis of patients with GIST containing an air-fluid level. Data of GIST patients, spanning 5 years, including 17 GIST patients with air-fluid levels in the experimental group and 34 GIST patients without air-fluid levels in the control group, were retrieved from two hospitals in China. The clinicopathological characteristics, types of surgery, management, and clinical outcomes of GIST patients were compared between the two groups. GISTs containing air-fluid levels were significantly different from GISTs without air-fluid levels regarding tumor morphology, NIH risk category, invasion of adjacent organs, and necrosis or ulceration. Most GIST patients with air-fluid levels (14/17, 82.4%) received open surgery, significantly higher than the 20.6% in the control group. Targeted therapy with Imatinib mesylate (IM) was implemented in all GIST patients in the experimental group (17/17, 100%); markedly higher than those (3/34, 8.8%) in the control group. During follow-up, recurrence and death rates (5.9% and 5.9%) in the experimental group were higher than those (2.9% and 0%) in the control group. Open surgery is commonly performed in GIST patients with air-fluid levels who also require targeted therapy with IM. The Torricelli-Bernoulli sign could be a risk factor, adversely affecting the patient’s prognosis.

Adjuvant Imatinib Treatment for 5-Years vs 3-Years in Patients with Ruptured Localized Gastrointestinal Stromal Tumor: A Retrospective Analysis

Purpose

Three years of adjuvant imatinib is the standard treatment for resected gastrointestinal stromal tumors (GISTs) with rupture, but the recurrence rate is prominently high. We aimed to investigate the efficacy and safety of 5-year adjuvant imatinib compared with 3-year treatment in patients with a ruptured GIST following surgical resection.

Materials and Methods

A total of 51 patients were included in the analysis. The assessment of GIST rupture was based on Nishida’s classification. Twenty patients who were diagnosed before November 2013 were treated with 5 years of imatinib, and 31 patients who were diagnosed after November 2013 were treated with 3 years of imatinib. We retrospectively compared the clinical outcomes of the two groups.

Results

Baseline characteristics and the incidence of the adverse events were generally comparable between the two groups. During a median follow-up duration of 43.8 months and 104.2 months in the 3- and 5-year group, 8 and 9 patients had a disease recurrence, respectively. The 5-year group showed better recurrence-free survival (RFS) than the 3-year group. In multivariate analysis, low mitotic index was a significant independent favorable prognostic factor for RFS, while 5-year imatinib treatment was marginally associated with a favorable RFS.

Conclusion

Five years of adjuvant imatinib treatment in patients with ruptured GIST was associated with favorable survival outcomes with manageable toxicity profiles. Our findings warrant validation and confirmation in future studies.

Recent Progress and Challenges in the Diagnosis and Treatment of Gastrointestinal Stromal Tumors

Simple Summary

Gastrointestinal stromal tumors (GIST) are potentially malignant tumors and require evidence-based surgical and/or medical treatment. Laparoscopy has similar safety and prognostic outcomes to those of laparotomy and is currently a standard procedure for localized GISTs. However, surgery for gastric GISTs less than 2 cm may be re-evaluated due to the indolent nature of the GIST and other competing risks among GIST patients. A work-up with endoscopy and endoscopic ultrasonography as well as endoscopic or percutaneous biopsy is important for the preoperative diagnosis of GISTs. Medical treatment with tyrosine kinase inhibitors is the mainstay for recurrent/metastatic GISTs. The activity of an individual drug is well correlated with gene alterations, and, in the era of precision medicine, cancer genome profiling should be considered before medical treatment.

Abstract

Gastrointestinal stromal tumors (GISTs) are the most frequent malignant mesenchymal tumors in the gastrointestinal tract. The clinical incidence of GISTs is estimated 10/million/year; however, the true incidence is complicated by frequent findings of tiny GISTs, of which the natural history is unknown. The initial work-up with endoscopy and endoscopic ultrasonography plays important roles in the differential diagnosis of GISTs. Surgery is the only modality for the permanent cure of localized GISTs. In terms of safety and prognostic outcomes, laparoscopy is similar to laparotomy for GIST treatment, including tumors larger than 5 cm. GIST progression is driven by mutations in KIT or PDGFRA or by other rare gene alterations, all of which are mutually exclusive. Tyrosine kinase inhibitors (TKIs) are the standard therapy for metastatic/recurrent GISTs. Molecular alterations are the most reliable biomarkers for TKIs and for other drugs, such as NTRK inhibitors. The pathological and genetic diagnosis prior to treatment has been challenging; however, a newly developed endoscopic device may be useful for diagnosis. In the era of precision medicine, cancer genome profiling by targeted gene panel analysis may enable potential targeted therapy even for GISTs without KIT or PDGFRA mutations.

Gastrointestinal stromal tumor: a review of current and emerging therapies

Gastrointestinal stromal tumors (GIST) are rare neoplasms arising from the interstitial cell of Cajal in the gastrointestinal tract. Two thirds of GIST in adult patients have c-Kit mutation and smaller fractions have platelet derived growth factor receptor alpha (PDGFRA) mutation. Surgery is the only curative treatment for localized disease. Imatinib improves survival when used adjuvantly and in advanced disease. Several targeted therapies have also improved survival in GIST patients after progression on imatinib including sunitinib and regorafenib. Recently, United States Federal and Drug Administration (FDA) approved two new tyrosine kinase inhibitors for the treatment of heavily pretreated advanced/unresectable GIST including avapritinib (a selective inhibitor for PDGFRA exon 18 mutation including D842V mutations) and ripretinib (a broad-spectrum kinase inhibitor of c-Kit and PDGFRA). In this article, we will provide a comprehensive review of GIST including the current standard of care treatment and exploring future paradigm shifts in therapy.

Rectovaginal extragastrointestinal stromal tumour (EGIST): an additional entity to be considered in the differential diagnosis of tumours of the rectovaginal septum

Gastrointestinal stromal tumours (GISTs) are rare - and rectovaginal extragastrointestinal stromal tumours (RV-EGISTs) even rarer. We share a case of RV-EGIST, complemented by high-quality radiological and surgical images. A review of current literature pertaining to RV-EGIST is also included. Our case report highlights the diagnostic challenge presented by extragastrointestinal stromal tumours. Differentiated from overlapping pathologies only by targeted application of immunohistopathology and cytogenetics, the inclusion of RV-EGIST in the differential diagnosis of a rectovaginal tumour is essential to making this correct diagnosis. Primary surgery is the treatment of choice for RV-EGIST if complete cytoreduction can be achieved, combined with adjuvant tyrosine kinase inhibitor (TKI) therapy for those with high-risk features to further reduce rates of future recurrence.

Association between R1 resection and oncological outcome in resectable gastrointestinal stromal tumors without tumor rupture: A systematic review and meta-analysis

BACKGROUND

The influence of positive microscopic margin (R1) resection on the prognosis of gastrointestinal stromal tumors (GISTs) is controversial. Tumor rupture is significantly associated with the occurrence of R1 resection and may be a confounder of R1 resection in GISTs. The present meta-analysis evaluated the real influence of R1 resection on the prognosis of GISTs by excluding the confounding effect of tumor rupture.

METHODS

The PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov databases were searched. Studies that compared R1 with negative microscopic margin (R0) resection in GIST patients and reported the time-to-event data of recurrence-free survival (RFS) or disease-free survival (DFS) were eligible for inclusion. The quality of the observational studies was assessed using the Newcastle-Ottawa scale.

RESULTS

Of the 4896 records screened, 23 retrospective studies with 6248 participants were selected. In the overall analysis, R1 resection resulted in a significantly shorter RFS/DFS than R0 resection for GISTs (HR = 1.80, 95% CI = 1.54-2.10, P < 0.001, I² = 14%). However, the inferior RFS/DFS vanished when tumor rupture cases were excluded (HR = 1.34, 95% CI = 0.98-1.83, P = 0.07, I² = 33%). Sensitivity analysis by high-quality studies brought about a more robust HR of 1.15 (95% CI = 0.88-1.50, P = 0.29), with low heterogeneity (I² = 0%). The qualities of evidence for the outcomes were high.

CONCLUSIONS

This meta-analysis shows that R1 resection did not influence the survival outcome of GISTs. Reresection may not be necessary when positive microscopic margins exist. This analysis could provide high-quality evidence for the development of guidelines.

Nomogram to Predict Preoperative Occult Peritoneal Metastasis of Gastrointestinal Stromal Tumors (GIST) Based on Imaging and Inflammatory Indexes

Background

Preoperative imaging examination is the primary method for diagnosing metastatic gastrointestinal stromal tumor (GIST), but it is associated with a high rate of missed diagnosis. Therefore, it is important to establish an accurate model for predicting occult peritoneal metastasis (PM) of GIST.

Patients and Methods

GIST patients seen between April 2002 and December 2018 were selected from an institutional database. Using multivariate logistic regression analyses, we created a nomogram to predict occult PM of GIST and validated it with an independent cohort from the same center. The concordance index (C-index), decision curve analysis (DCA) and a clinical impact curve (CIC) were used to evaluate its predictive ability.

Results

A total of 522 eligible GIST patients were enrolled in this study and divided into training (n=350) and validation cohorts (n=172). Factors associated with occult PM were included in the model: tumor size (odds ratio [OR] 1.194 95% confidence interval [CI], 1.034-1.378; p=0.016), primary location (OR 7.365 95% CI, 2.192-24.746; p=0.001), tumor capsule (OR 4.282 95% CI, 1.209-15.166; p=0.024), Alb (OR 0.813 95% CI, 0.693-0.954; p=0.011) and FIB (OR 2.322 95% CI, 1.410-3.823; p=0.001). The C-index was 0.951 (95% CI, 0.917-0.985) in the training cohort and 0.946 (95% CI, 0.900-0.992) in the validation cohort. In the training cohort, the prediction model had a sensitivity of 82.8%, a specificity of 93.8%, a positive predictive value of 54.7%, and a negative predictive value of 98.4%; the validation cohort values were 94.7%, 85.0%, 43.9% and 99.2%, respectively. DCA and CIC results showed that the nomogram had clinical value in predicting occult PM in GIST patients.

Conclusion

Imaging and inflammatory indexes are significantly associated with microscopic metastases of GIST. A nomogram including these factors would have an excellent ability to predict occult PM.

The analysis of 3-year adjuvant therapy with imatinib in patients with high-risk molecular profiled gastrointestinal stromal tumors (GIST) treated in routine practice

INTRODUCTION

The real-world data on adjuvant imatinib therapy in high-risk primary GIST are scarce.

METHODS

We have analysed the data of 107 consecutive patients with gastrointestinal stromal tumour (GIST) after resection treated with adjuvant imatinib (for planned 3 years with initial dose 400 mg daily, started not later than 4 months after operation) in 6 oncological centres in 2013-2018. All patients were required to have high risk of recurrence (at least 50% according to NCCN/AFIP criteria), known mutational status to exclude PDGFRA D842V mutants and KIT/PDGFRA-wild type cases from therapy without any further selection. Median follow-up time was 27 months.

RESULTS

The most common primary localization of GIST was small bowel (63 patients; 59%), followed by the stomach (40 patients; 37%). The majority of GIST cases harboured exon 11 KIT mutations (88 cases, 82%), 11 cases had exon 9 KIT mutations (10%), 8 had other KIT/PDGFRA mutations potentially sensitive to imatinib. Forty patients (37%) finished 3-year adjuvant imatinib therapy as planned, 48 (45%) still continue therapy, 5 (4.5%) patients had finished adjuvant therapy prematurely due to toxicity, 6 (6%) due to disease progression on treatment and 8 (7.5%) due to other reasons. The disease relapse was detected in 19 patients, of them in 5 cases in exon 9 KIT mutants (45%), and 14 cases in patients with exon 11 KIT mutations (11%) [p < 0.01]. Estimated 4-year relapse-free survival (RFS) rate is 78%.

CONCLUSIONS

The early results of adjuvant therapy with imatinib in routine practice outside clinical trials in high-risk mutation-driven GIST patients only confirm high efficacy of this therapy with better tolerability than in clinical trials. We found overrepresentation of exon 9 KIT mutants and ruptured tumors in a group of patients with disease relapse.

Prognostic Indicators for Gastrointestinal Stromal Tumors: A Review

Gastrointestinal stromal tumors (GISTs) are potentially malignancies that can occur anywhere in the digestive tract. Tyrosine kinase inhibitors (TKIs) such as imatinib have proven effective since the discovery of KIT and PDGFRA. The current version of NCNN, ESMO and EURACAN guidelines recognized that the three main prognostic factors are the mitotic rate, tumor size and tumor site. In addition, tumor rupture is also recognized as an independent risk factor. However, recent evidence shows that various types of gene mutations are associated with prognosis, and influencing factors such as gastrointestinal bleeding and high Ki67 index have been associated with poor prognosis. It shows that the current risk classification is still insufficient and controversial. With the emergence of more and more lack mutation in KIT/PDGFRA GISTs (KIT/PDGFRA wild-type GISTs) or drug resistance genes, primary and secondary drug resistance problems are caused, which makes the treatment of late or metastatic GIST face challenges. Therefore, this article will review the clinicopathological characteristics of GIST, the special molecular subtypes and other factors that may affect prognosis. We will also explore reliable prognostic markers for better postoperative management and improve the prognosis of patients with GIST.

Quality of Surgery and Outcome in Localized Gastrointestinal Stromal Tumors Treated Within an International Intergroup Randomized Clinical Trial of Adjuvant Imatinib

Importance

The association between quality of surgery and overall survival in patients affected by localized gastrointestinal stromal tumors (GIST) is not completely understood.

Objective

To assess the risk of death with and without imatinib according to microscopic margins status (R0/R1) using data from a randomized study on adjuvant imatinib.

Design, Setting, and Participants

This is a post hoc observational study on patients included in the randomized, open-label, phase III trial, performed between December 2004 and October 2008. Median follow-up was 9.1 years (IQR, 8-10 years). The study was performed at 112 hospitals in 12 countries. Inclusion criteria were diagnosis of primary GIST, with intermediate or high risk of relapse; no evidence of residual disease after surgery; older than 18 years; and no prior malignancies or concurrent severe/uncontrolled medical conditions. Data were analyzed between July 17, 2017, and March 1, 2020.

Interventions

Patients were randomized after surgery to either receive imatinib (400 mg/d) for 2 years or no adjuvant treatment. Randomization was stratified by center, risk category (high vs intermediate), tumor site (gastric vs other), and quality of surgery (R0 vs R1). Tumor rupture was included in the R1 category but also analyzed separately.

Main Outcomes and Measures

Primary end point of this substudy was overall survival (OS), estimated using Kaplan-Meier method and compared between R0/R1 using Cox models adjusted for treatment and stratification factors.

Results

A total of 908 patients were included; 51.4% were men (465) and 48.6% were women (440), and the median age was 59 years (range, 18-89 years). One hundred sixty-two (17.8%) had an R1 resection, and 97 of 162 (59.9%) had tumor rupture. There was a significant difference in OS for patients undergoing an R1 vs R0 resection, overall (hazard ratio [HR], 2.05; 95% CI, 1.45-2.89) and by treatment arm (HR, 2.65; 95% CI, 1.37-3.75 with adjuvant imatinib and HR, 1.86; 95% CI, 1.16-2.99 without adjuvant imatinib). When tumor rupture was excluded, this difference in OS between R1 and R0 resections disappeared (HR, 1.05; 95% CI, 0.54-2.01).

Conclusions and Relevance

The difference in OS by quality of surgery with or without imatinib was associated with the presence of tumor rupture. When the latter was excluded, the presence of R1 margins was not associated with worse OS.

Trial Registration

ClinicalTrials.gov Identifier: NCT00103168.

Gastrointestinal Stromal Tumors of the Small Intestine: Progress in Diagnosis and Treatment Research

In recent years, the diagnosis and treatment of gastrointestinal stromal tumors (GISTs) of the small intestine have been a hot topic due to their rarity and non-specific clinical manifestations. With the development of gene and imaging technology, surgery, and molecular targeted drugs, the diagnosis and treatment of GISTs have achieved great success. For a long time, radical resection was prioritized to treat GISTs of the small intestine. At present, preoperative tumor staging is a novel treatment for unresectable malignant tumors. In addition, karyokinesis exponent is the sole independent predictor of progression-free survival of GISTs. The DNA, miRNA, and protein of exosomes have also been found to be biomarkers with prognostic implications. The research on the treatment of GISTs has become a focus in the era of precision medicine, ushering in the use of standardized, normalized, and individualized treatment.

Management and outcomes of ruptured, perforated or fistulized tumors of mesenchymal origin

BACKGROUND

Patients with ruptured, perforated or fistulized (RPF) sarcomas commonly have issues such as sepsis and malnutrition and are usually unsuitable for oncologic resection in the emergency setting. We present our approach for managing a series of patients and the outcomes which were achieved with multidisciplinary care.

METHODS

We reviewed records of patients referred to the section of sarcoma surgical oncology. Clinicopathologic factors, preoperative and operative interventions as well as short-term oncologic outcomes were assessed.

RESULTS

Sixteen patients were identified between 1 January 1998 to 31 December 2018. Median age was 42.8 years. Histologies were; Gastrointestinal stromal tumors (7), desmoid (4), spindle cell tumor (2), dedifferentiated liposarcoma (2), and nonseminomatous germ cell tumor (1). Five patients had preoperative sepsis, 8 received antimicrobials, and 50% required hospitalization with a median stay of 21 days. Total parenteral nutrition was administered to 5 (31.3%) patients. Median tumor size and estimated blood loss were 13.1 cm and 350 mL respectively. No perioperative mortality occurred. Two patients have expired at a median follow-up of 16.1 months.

CONCLUSION

Preoperative optimization, including the use of percutaneous drains, and antibiotics to control sepsis, where necessary, can lead to eventual oncologic resection with acceptable morbidity and no short-term mortality for patients with RPF sarcomas.

Is Peritoneal Tumor Penetration of Prognostic Importance in Gastrointestinal Stromal Tumors?

BACKGROUND

Peritoneal tumor penetration (PP) strongly affects prognosis in gastrointestinal carcinomas. In gastrointestinal stromal tumor (GIST), its significance in the absence of tumor rupture has not been subjected to detailed analysis.

METHODS

Patients undergoing complete resection for non-metastatic GIST from 2000 to 2017 were identified in the regional sarcoma database at Oslo University Hospital. Patients with extraperitoneal tumors (esophagus, rectum) or ruptured tumors were excluded from the study. Rupture was defined according to the Oslo criteria, and PP was assessed via routine histopathologic examination by sarcoma pathologists.

RESULTS

The study enrolled 341 patients. The median follow-up period was 51 months (range 0-175) months. In 82 (24%) of the 341 patients, PP was recorded. There were 32 recurrences, 9 in patients with PP and 23 in patients without PP. Despite statistically significant associations between PP and established risk factors (size, mitotic index, non-gastric location), the 5-year recurrence-free survival rate did not differ between the patients with PP (86%) and those without PP (90%) (hazard ratio 1.25; 95% confidence interval 0.58-2.70; P = 0.577). Adjuvant imatinib was administered to 53 of 97 patients in the high-risk category. The recurrence rates did not differ between the PP-positive and PP-negative patients in either group.

CONCLUSIONS

In GIST, PP without tumor rupture appears not to influence prognosis. This lack of prognostic significance may reflect unexplored differences between epithelial and mesenchymal malignancies.

The prognostic value of gastrointestinal bleeding in gastrointestinal stromal tumor: A propensity score matching analysis

Background and objectives

Whether gastrointestinal (GI) bleeding indicates gastrointestinal stromal tumor (GIST) rupture and impacts prognosis is unclear. We examined the prognostic value of GI bleeding in GIST.

Methods

Primary GIST patients with (GB group) or without (NGB group) initial symptoms of GI bleeding were retrospectively studied. Propensity score matching (PSM) was conducted to reduce confounders.

Results

Eight hundred patients were enrolled. Male gender [odds ratio (OR) = 1.517, P = 0.011], tumors in the small intestine (OR = 2.539, P < 0.001), and tumor size 5‐10 cm (OR = 2.298, P = 0.004) increased the odds of GI bleeding; age >60 years decreased the odds (OR = 0.683, P = 0.031). After PSM, 444 patients were included (222 in each group). Relapse‐free survival (RFS) (P = 0.001) and overall survival (OS) (P = 0.002) were both superior in the GB group. In subgroup analysis, the GB group achieved a superior RFS (P = 0.005) and OS (P = 0.007) in patients with small intestine GIST, but not stomach or colorectal GIST.

Conclusions

GIST patients with age <60, male gender, tumors located in the small intestine, and tumors 5‐10 cm in size had a higher risk of GI bleeding. GIST patients with GI bleeding had a superior RFS and OS. This difference was statistically significant only in small intestine GIST.

Defining Tumor Rupture in Gastrointestinal Stromal Tumor

Tumor rupture is an important risk factor predictive of recurrence after macroscopically complete resection of gastrointestinal stromal tumors (GISTs), and an indication for defined interval or even lifelong adjuvant therapy with imatinib according to guidelines. However, there is no consensus or universally accepted definition of the term ‘tumor rupture’, and, consequently, its incidence varies greatly across reported series. Without predefined criteria, the clinical significance of rupture has also been difficult to assess on multivariate analysis of retrospective data. We reviewed the relevant literature and international guidelines, and, based on the Oslo criteria, proposed the following six definitions for ‘tumor rupture’: (1) tumor fracture or spillage; (2) blood-stained ascites; (3) gastrointestinal perforation at the tumor site; (4) microscopic infiltration of an adjacent organ; (5) intralesional dissection or piecemeal resection; or (6) incisional biopsy. Not all minor defects of tumor integrity should not be classified as rupture, i.e. mucosal defects or spillage contained within the gastrointestinal lumen, microscopic tumor penetration of the peritoneum or iatrogenic damage only to the peritoneal lining, uncomplicated transperitoneal needle biopsy, and R1 resection. This broad definition identifies GIST patients at particularly high risk of recurrence in population-based cohorts; however, its applicability in other sarcomas has not been investigated. As the proposed definition of tumor rupture in GIST has limited evidence based on the small number of patients with rupture in each retrospective study, we recommend validating the proposed definition of tumor rupture in GIST in prospective studies and considering it in clinical practice.

What is the appropriate duration of adjuvant imatinib mesylate treatment for primary gastrointestinal stromal tumors classified according to the strict definition of tumor rupture?

In gastrointestinal stromal tumors (GISTs), rupture is a high-risk feature; however, "tumor rupture" is inconsistently defined, and its prognostic value remains controversial.Six hundred ninety-one patients undergoing surgery for primary nonmetastatic GISTs from 2003 to 2015 at our institution were enrolled. The strict definitions of "tumor rupture" according to the Kinki GIST Study Group (KGSG) were used.The median follow-up time was 64 months. The 5-year recurrence-free survival (RFS) and overall survival (OS) rates in the entire group were 79.3% and 84.1%, respectively. According to the KGSG's definition, tumor rupture occurred only in 24 (3.5%) of 691 patients. For all 691 patients, multivariable analysis showed that tumor rupture, according to KGSG's definition, is one of the independently prognostic factors for both RFS and OS. Twenty-four patients with tumor rupture were further analyzed. Receiving IM for more than 3 years was significantly associated with improved RFS and OS in GISTs patients with tumor rupture.Tumor rupture according to KGSG's definition was an independent predictive factor associated with GIST patient prognosis. More importantly, for GISTs with tumor rupture according to the KGSG's strict definition, receiving IM treatment for ≥3 years should be considered.

A new nomogram for recurrence-free survival prediction of gastrointestinal stromal tumors: Comparison with current risk classification methods

BACKGROUND

This study aimed to build a new risk stratification nomogram for gastrointestinal stromal tumors (GISTs) focused on a popular factor Ki-67 to enable individualized and precise predictions of the most suitable candidates for imatinib therapy.

METHODS

We retrospectively collected clinicopathologic data of the patients diagnosed with GISTs from January 1998 to December 2015 at Southern Medical University Nanfang Hospital as the experiment group. And patients with GISTs at the Sun Yat-sen University Cancer Center from January 2007 to December 2012 were included as the validation group. The nomogram was built using Kaplan-Meier method and the Cox proportional hazards regression model. The receiver operating characteristic (ROC) curves were established to compare the discriminative ability of the new nomogram with other risk stratification systems, including the modified National Institute of Health (modified NIH) criteria, Armed Forces Institute of Pathology (AFIP) criteria, Memorial Sloan Kettering Cancer Center (MSKCC) prognostic nomogram, and contour maps.

RESULTS

In univariate analysis, the tumor size, site, mitotic count, tumor rupture and Ki-67 labeling index were significant factors (all P < 0.05) and included in the Cox model to build our nomogram. According to the ROC curve, our new nomogram showed the largest AUC value (0.778) compared with that of the other classification methods (contour maps, AUC = 0.743; AFIP, AUC = 0.719; MSKCC, AUC = 0.712; and modified NIH, AUC = 0.719).

CONCLUSION

Our new nomogram exhibits an excellent performance and might become a potential risk stratification to support therapeutic decision-making for GISTs.

Genotype and risk of tumour rupture in gastrointestinal stromal tumour

BACKGROUND

Tumour rupture is a strong predictor of poor outcome in gastrointestinal stromal tumours (GISTs) of the stomach and small intestine. The objective was to determine whether tumour genotype was associated with risk of rupture.

METHODS

Rupture was classified according to the definition proposed by the Oslo Sarcoma Group. Since January 2000, data were registered retrospectively for all patients at Oslo University Hospital undergoing surgery for localized GIST of the stomach or small intestine. Tumour genotype was analysed by Sanger sequencing.

RESULTS

Two hundred and nine patients with mutation data available were identified. Tumour rupture occurred in 37 patients. Among the 155 patients with KIT exon 11 mutations, an increased risk of rupture was observed with a deletion or insertion-deletion (25 of 86, 29 per cent) compared with substitutions (5 of 50, 10 per cent) or duplications/insertions (2 of 19, 11 per cent) (P = 0·014). Notably, rupture occurred in 17 of 46 tumours (37 per cent) with deletions involving codons 557 and 558 (del557/558) versus 15 of 109 (13·8 per cent) with other exon 11 mutations (P = 0·002). This association was confined to gastric tumours: 12 of 34 (35 per cent) with del557/558 ruptured versus six of 77 (8 per cent) with other exon 11 mutations (P = 0·001). In multivariable logistic regression analysis, del557/558 and tumour size were associated with an increased likelihood of tumour rupture, but mitotic count was not.

CONCLUSION

Gastric GISTs with KIT exon 11 deletions involving codons 557 and 558 are at increased risk of tumour rupture. This high-risk feature can be identified in the diagnostic evaluation and should be included in the assessment when neoadjuvant imatinib treatment is considered.

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

Background

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

Methods

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

Results

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

Conclusion

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

Neoadjuvant Therapy to Downstage the Extent of Resection of Gastrointestinal Stromal Tumors

INTRODUCTION

Gastrointestinal stromal tumors (GIST) are rare malignant tumors in terms of incidence, and they are not linked to specific symptoms. Often, primary tumors, particularly of the stomach, rectum, or rectovaginal space, are quite large when detected, and multivisceral resection seems to be the treatment of choice as the mainstay of therapy is complete tumor removal. If a gain-of-function mutation in the KIT gene is present, drug therapy with receptor tyrosine kinase inhibitors (RTKIs) might significantly downstage primary GIST tumors.

METHODS

A review of the literature was performed to identify the current evidence for preoperative treatment of GIST regarding toxicity, efficacy, and oncological outcome, including mutational data from our own database.

RESULTS

Four phase II as well as several cohort studies showed acceptable toxicity and no increased perioperative morbidity of preoperative imatinib. Progressive disease during preoperative treatment was a rare event, and partial response was achieved in 40-80% of all patients. For methodological reasons, the trials cannot prove an oncological long-term superiority of preoperative treatment.

CONCLUSION

Preoperative therapy with imatinib is safe and recommended for patients with locally advanced GIST. Neoadjuvant imatinib therapy may enable less invasive and organ-sparing surgery, avoid tumor rupture during extensive resectional procedures, and improve the quality of perioperative RTKI treatment.

Is the Surgical Margin in Gastrointestinal Stromal Tumors Different?

Background

Radical surgical excision is the mainstay of therapy of primary, nonmetastatic gastrointestinal stromal tumors (GIST) and margin status after surgery is a significant prognostic factor.

Methods and Results

The aim of this paper is to review principles in primary GIST surgery, i.e. differences between R0, R1, and R2 resection, to describe how surgical margin status and tumor intraperitoneal rupture influence the patients' outcome, and how this may be effected by neoadjuvant and adjuvant treatment in locally advanced tumors. A systematic search of literature published between 2000 and 2018 was performed regarding this topic.

Conclusion

Correct interpretation of margin status after surgery can be affected by many factors during operation and preparation of tissue.

Clinicopathological Features and Prognosis of Primary GISTs with Tumor Rupture in the Real World

Background

Patients with ruptured gastrointestinal stromal tumor (GIST) are recommended for imatinib adjuvant therapy; however, their clinicopathological features and prognosis in the era of imatinib are unknown.

Patients and Methods

The study cohort included 665 patients with histologically proven primary GISTs who underwent R0 or R1 surgery between 2003 and 2007; the validation cohort included 182 patients between 2000 and 2014. The definitions of tumor rupture in the study included perforation at tumor site, tumor fracture, piecemeal resection including open biopsy, and macroscopic injuries to the pseudocapsule.

Results

Tumor rupture occurred in 21 (3.2%) of 665 and 5 (2.9%) of 182 patients in the study and validation cohort, respectively. Ruptured GISTs were more symptomatic, were larger in size, and had higher mitotic count than nonruptured GISTs but were not associated with tumor location or laparoscopic surgery. GISTs with intraoperative rupture had clinicopathological features and prognostic outcomes similar to those with preoperative rupture. Recurrence rates were higher and median recurrence-free survival (RFS) and overall survival (OS) were shorter with ruptured than nonruptured GIST. Tumor rupture was one of the independent prognostic factors for RFS, but not OS, according to multivariate analysis.

Conclusions

Ruptured GISTs were symptomatic larger tumors with high mitotic activity, frequent relapse, and shorter RFS. Tumor rupture was an independent prognostic factor for RFS, but not for OS, in the era of imatinib.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-6505-7) contains supplementary material, which is available to authorized users.