Pattern of recurrence in patients with ruptured primary gastrointestinal stromal tumour

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.

Surgical outcomes of locally advanced gastrointestinal stromal tumors after multivisceral resection: A retrospective study of 64 patients at a single institution

To analyze the outcome in patients who have undergone multivisceral resection (MVR) for locally advanced gastrointestinal stromal tumors (GISTs), and identify the risk factors for tumor recurrence and postoperative morbidity. Sixty-four patients who operated for locally advanced GISTs with MVR in PPeking University Cancer Hospital Sarcoma Center (PUCHSC) between 2013 and 2021 were identified. Clinicopathologic characteristics, surgical outcomes, recurrence, and 5-year recurrence-free and overall survival were evaluated. The mean age of the patients was 60 years. Mean tumor size was 11.1 cm. Complete resection was achieved in all patients. The estimated 5-year recurrence-free and overall survival were 86.6% and 90.0%, respectively. Independent factor of recurrence following surgery was mitotic count on multivariate analysis. Overall postoperative morbidity was 53.1% (n = 34). Severe morbidity was 21.9% (n = 14). The most common severe complication was clinically relevant pancreatic fistula (n = 12, 18.8%), followed by anastomotic leakage (n = 4, 6.3%) and Intraabdominal abscess (n = 4, 6.3%). Multivariate analysis showed that preoperative imatinib therapy could reduce overall morbidity. Long operation time, combined colectomy and pancreatectomy were independent risk factors for postoperative severe morbidity. Compared to partial pancreatectomy, pancreaticoduodenectomy (PD) was significantly increased the incidence of severe morbidity. In conclusion, compared to systemic therapy alone, the outcome of locally advanced GISTs after MVR was more favorable. Despite the high overall morbidity, the postoperative severe morbidity and mortality of MVR were acceptable. Preoperative imatinib therapy should be recommended whenever possible. Combined pancreatectomy and colectomy are associated with significant postoperative severe morbidities. PD should be thoroughly discussed and be subject to MDT approach before surgery.

Gastrointestinal Malignancy: Genetic Implications to Clinical Applications

Advances in molecular genetics have revolutionized our understanding of the pathogenesis, progression, and therapeutic options for treating gastrointestinal (GI) cancers. This chapter provides a comprehensive overview of the molecular landscape of GI cancers, focusing on key genetic alterations implicated in tumorigenesis across various anatomical sites including GIST, colon and rectum, and pancreas. Emphasis is placed on critical oncogenic pathways, such as mutations in tumor suppressor genes, oncogenes, chromosomal instability, microsatellite instability, and epigenetic modifications. The role of molecular biomarkers in predicting prognosis, guiding treatment decisions, and monitoring therapeutic response is discussed, highlighting the integration of genomic profiling into clinical practice. Finally, we address the evolving landscape of precision oncology in GI cancers, considering targeted therapies and immunotherapies.

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.

2023 GEIS Guidelines for gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GIST) is the most common malignant neoplasm of mesenchymal origin. GIST spans a wide clinical spectrum that ranges from tumors with essentially no metastatic potential to malignant and life-threatening spread diseases. Gain-of-function mutations in KIT or PDGFRA receptor tyrosine kinases are the crucial drivers of most GISTs, responsible for tumor initiation and evolution throughout the entire course of the disease. The introduction of tyrosine kinase inhibitors targeting these receptors has substantially improved the outcomes in this formerly chemoresistant cancer. As of today, five agents hold regulatory approval for the treatment of GIST: imatinib, sunitinib, regorafenib, ripretinib, and avapritinib. This, in turn, represents a success for a rare neoplasm. During the past two decades, GIST has become a paradigmatic model in cancer for multidisciplinary work, given the disease-specific particularities regarding tumor biology and tumor evolution. Herein, we review currently available evidence for the management of GIST. This clinical practice guideline has been developed by a multidisciplinary expert panel (oncologist, pathologist, surgeon, molecular biologist, radiologist, and representative of patients' advocacy groups) from the Spanish Group for Sarcoma Research, and it is conceived to provide, from a critical perspective, the standard approach for diagnosis, treatment, and follow-up.

KIT and PDGFRA Variants and the Survival of Patients with Gastrointestinal Stromal Tumor Treated with Adjuvant Imatinib

Adjuvant imatinib improves the recurrence-free survival and overall survival (OS) of patients with gastrointestinal stromal tumors (GISTs) who have a high risk of recurrence after surgery and is now considered standard treatment. Yet, OS benefit has been demonstrated in only one randomized study, the Scandinavian Sarcoma Group XVIII/AIO trial, where patients with high-risk GISTs were allocated to either 1 year or 3 years of adjuvant imatinib. SSGXVIII/AIO is also the only randomized trial in which adjuvant imatinib duration exceeding 2 years was evaluated. In this trial, the 3-year treatment led to a 45% reduction in the risk of death during the first 10 years that followed random allocation even though some of the patients did not have GISTs at tumor histology review, had mutations now known to be imatinib-resistant or had non-localized disease at study entry. In the subgroup of patients who had KIT exon 11 deletion/indel mutation, the reduction in the risk of death was 66% in favor of the longer treatment. Proper patient selection is of crucial importance since many patients are cured with surgery. Little evidence for OS benefit is available from randomized trials for patients whose GIST harbors KIT exon 9 mutation, KIT insertion mutation, PDGFRA D842V mutation, or lacks KIT and PDGFRA mutations. Adjuvant imatinib improves OS substantially if high-risk GISTs can be identified, treatment duration is long enough, and GISTs harbor an imatinib-sensitive mutation.

Risk factors of perforation in gastric stromal tumors during endoscopic resection: a retrospective case-control study

BACKGROUND AND AIMS

Perforation is a common complication during endoscopic resection (ER) of gastric gastrointestinal stromal tumors (gGISTs) associated with secondary infections, sepsis, hospitalization time and cost. However, the risk factors of perforation remain controversial. This study aimed to investigate the risk factors for perforation during ER of gGISTs.

METHODS

This retrospective case-control study included consecutive patients with gGISTs who underwent ER between June 2009 and November 2021 at the Nanjing Drum Tower Hospital. Univariate and multivariate analyses were performed to investigate the risk factors for perforation. Sensitivity analyses with propensity scoring (PS) were performed to evaluate the stability of the independent effects.

RESULTS

In total, 422 patients with gGISTs were included. The following factors were associated with perforation during ER: in the non-intraluminal growth patterns (all confounders adjusted odds ratio [aOR]: 5.39, 95% CI 2.99-9.72, P < 0.001), in the gastric fundus (aOR 2.25, 95% CI 1.40-3.60, P = 0.007), sized ≥ 2 cm (aOR 1.70, 95% CI 1.04-2.77, P = 0.035), in the lesser curvature (aOR 0.12, 95% CI 0.05-0.27, P < 0.001), and in the gastric cardia (aOR 0.13, 95% CI 0.04-0.50, P = 0.003). The PS analysis confirmed the stable independent effects of these identified risk factors.

CONCLUSIONS

ERs of gGISTs in non-intraluminal growth patterns, in the gastric fundus, and with larger tumor size were independent risk factors for perforation. While tumors in the lesser curvature or gastric cardia were independent protective factor for perforation.

Oncological outcomes of large gastrointestinal stromal tumors treated by laparoscopic resection

BACKGROUND

The resection of large gastric gastrointestinal stromal tumors (GISTs) by laparoscopic has been controversial. Extending from our prior study, the long-term oncological outcome of laparoscopic resection of large (5-8 cm) gastric GISTs was reported.

METHODS

From 2002 to 2018, a consecutive 66 patients with gastric GISTs of 5-8 cm were treated at National Taiwan University Hospital. Among them, 30 patients received open surgery, and 36 received laparoscopic surgery. The clinicopathological data, peri-operative and oncological outcomes were compared between groups.

RESULTS

The clinical demographics including sex, age, BMI, tumor locations and ratio of wedge resection were similar between groups. The mean tumor size was 6.0 ± 0.83 cm versus 6.3 ± 1.07 cm (Open vs. Laparoscopic, p = 0.3). The operation time, blood loss, and post-operative complications, were also similar. The mean hospital stay was shorter in the laparoscopic group (8.8 ± 2.5 days) than in the open group (12.0 ± 8.9 days), though not significantly different. The median follow-up time was 108 ± 58 months (97 ± 50 in laparoscopic group; 122 ± 64 in open group). All except three patients remain disease-free. One in the open group and two in the laparoscopic group had recurrence of tumor, and they were stable of disease under Imatinib treatment. Eight patients died in non-GIST causes during follow-up. The 5-year recurrence-free survival were 100% for the open and 94.2% for the laparoscopic group (p = 0.2).

CONCLUSION

Our data showed that laparoscopic surgery for gastric GIST between 5 and 8 cm was safe and oncologically feasible.

Advances of endoscopic and surgical management in gastrointestinal stromal tumors

As one of the most common mesenchymal malignancies in the digestive system, gastrointestinal stromal tumors (GISTs) occur throughout the alimentary tract with diversified oncological characteristics. With the advent of the tyrosine kinase inhibitor era, the treatment regimens of patients with GISTs have been revolutionized and GISTs have become the paradigm of multidisciplinary therapy. However, surgery resection remains recognized as the potentially curative management for the radical resection and provided with favorable oncological outcomes. The existing available surgery algorithms in clinical practice primarily incorporate open procedure, and endoscopic and laparoscopic surgery together with combined operation techniques. The performance of various surgery methods often refers to the consideration of risk evaluation of recurrence and metastases; the degree of disease progression; size, location, and growth pattern of tumor; general conditions of selected patients; and indications and safety profile of various techniques. In the present review, we summarize the fundamental principle of surgery of GISTs based on risk assessment as well as tumor size, location, and degree of progress with an emphasis on the indications, strengths, and limitations of current surgery techniques.

Ileal gastrointestinal stromal tumor presenting as retroperitoneal mass

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. It represents a wide range of clinical tumors with different clinical presentations, locations, and prognoses. Retroperitoneal GISTs are rarely seen and may be associated with the GI system. In this case report, we present the laparoscopic excision of retroperitoneal ileal GIST in a patient who was admitted to the outpatient clinic with abdominal pain.

[Gastrointestinal stromal tumors (GIST)]

Gastrointestinal stromal tumors (GIST) are rare tumors with a varying malignancy potential, most frequently located in the stomach and the small intestine. The median age at diagnosis is around 65 years. Standard treatment of localized disease is complete surgical resection. A GIST is generally resistant to conventional chemotherapy. Most GISTs harbor tyrosine kinase activating mutations in either the KIT or PDGFRA proto-oncogene. The standard treatment of locally advanced and metastatic GIST with such mutations is the tyrosine kinase inhibitor imatinib. In cases of progressive disease after successive treatment with imatinib, sunitinib, and regorafenib, a fourth-line therapy with ripretinib was recently approved. Approved in 2020, avapritinib is the first effective targeted therapy for advanced stage GIST harboring an imatinib-resistant PDGFRA D842V mutation.

A rare rectal gastrointestinal stromal tumor with indolent biological behavior: A case study

The overall incidence of rectal gastrointestinal stromal tumor (RGIST) has risen, but it remains a rare disease. Furthermore, tumor rupture is associated with poor prognosis. The present study reported a rare case of RGIST with indolent biological behavior. The biological behavior of this RGIST was analyzed and its malignant potential was evaluated using a guideline-based risk stratification assessment. The patient was diagnosed with a rectal tumor at the Third Affiliated Hospital of Qiqihar Medical University (Qiqihar, China) in April 2020 and a partial resection biopsy was then performed. This resection counts as a rupture. The biopsy confirmed RGIST and the patient refused further examination and treatment due to economic concerns. However, the patient survives with no tumor progression and metastasis until now, May 2022. In conclusion, based on the present case, tumor rupture in indolent RGIST is not necessarily associated with poor outcome.

Ki67 for evaluating the prognosis of gastrointestinal stromal tumors: A systematic review and meta‑analysis

Overexpression of Ki67 is observed in tumor cells, and it has been suggested to be a marker for cancer prognosis. However, the relationship between Ki67 expression and the risk of recurrence of gastrointestinal stromal tumors (GISTs) remains poorly defined. In the present study, a meta-analysis was used to examine the associations between Ki67 levels and GIST recurrence. Studies reporting GIST and Ki67 were found by searching Cochrane Library, PubMed and Embase until October 14, 2021. The Newcastle-Ottawa Scale (NOS) was used to verify the quality of the evidence. Totally, 1682 patient cases were included. The odds ratio (OR) estimates and 95% confidence interval (CI) for each publication were determined by a fixed-effects (Mantel-Haenszel) model. A total of 20 studies that fulfilled the inclusion criteria were finally included in the analysis. The average score of quality evaluation was 6.4 points according to NOS. It was found that Ki67 levels were significantly higher in the NIH L group compared with the NIH VL group (OR: 0.51; 95% CI: 0.26-0.99; P=0.04; P heterogeneity=0.44). There was also greater Ki67 overexpression in the NIH I group compared with the NIH L group (OR: 0.45, 95% CI: 0.31-0.65; P<0.0001; P heterogeneity=0.32), while Ki67 levels were greater in the NIH H group than in the NIH I group (OR: 0.20; 95% CI: 0.15-0.28; P<0.00001; P heterogeneity=0.56). In conclusion, Ki67 overexpression may be a useful marker of the risk of recurrent GIST transformation.

Intraoperative Near-Infrared Fluorescence Imaging with Indocyanine Green for Identification of Gastrointestinal Stromal Tumors (GISTs), a Feasibility Study

Simple Summary

Surgical resection plays a pivotal role in the treatment of GIST patients. The current study aims to explore the use of near-infrared fluorescence imaging to optimize the intraoperative tumor identification of GISTs. For this purpose, the potential and limitations of the widely used, and non-specific, tracer indocyanine green were assessed in a multicenter study including 10 patients. Our results show that GISTs typically have similar fluorescence intensity to the surrounding tissue, within several minutes after the intravenous administration of indocyanine green. These findings justify future research into specific fluorescent tracers for GISTs, and set a reference for future intraoperative imaging trials.

Abstract

Background: Optimal intraoperative tumor identification of gastrointestinal stromal tumors (GISTs) is important for the quality of surgical resections. This study aims to assess the potential of near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) to improve intraoperative tumor identification. Methods: Ten GIST patients, planned to undergo resection, were included. During surgery, 10 mg of ICG was intravenously administered, and NIRF imaging was performed at 5, 10, and 15 min after the injection. The tumor fluorescence intensity was visually assessed, and tumor-to-background ratios (TBRs) were calculated for exophytic lesions. Results: Eleven GIST lesions were imaged. The fluorescence intensity of the tumor was visually synchronous and similar to the background in five lesions. In one lesion, the tumor fluorescence was more intense than in the surrounding tissue. Almost no fluorescence was observed in both the tumor and healthy peritoneal tissue in two patients with GIST lesions adjacent to the liver. In three GISTs without exophytic growth, no fluorescence of the tumor was observed. The median TBRs at 5, 10, and 15 min were 1.0 (0.4–1.2), 1.0 (0.5–1.9), and 0.9 (0.7–1.2), respectively. Conclusion: GISTs typically show similar fluorescence intensity to the surrounding tissue in NIRF imaging after intraoperative ICG administration. Therefore, intraoperatively administered ICG is currently not applicable for adequate tumor identification, and further research should focus on the development of tumor-specific fluorescent tracers for GISTs.

[Mesenchymal tumors and tumor-like lesions of the gastrointestinal tract: an overview]

Mesenchymal tumors and tumor-like lesions of the gastrointestinal (GI) tract are uncommon. They vary from reactive tumefactive lesions and benign neoplasms to highly aggressive sarcomas. Among them, GI stromal tumors (GISTs) are most common, followed, with less frequency, by smooth muscle and neurogenic tumors. The major challenge resides in correctly identifying GISTs and providing a comprehensive report (including risk assessment and genotyping) that represents the basis for an optimized surgical-oncological treatment and/or adjuvant therapy. On the other hand, the challenge of benign lesions is to find a good name (well understandable and reproducible diagnostic term) that helps avoid diagnostic ambiguity and prognostic uncertainty so that overprognostication and overtreatment can be prevented. Moreover, several recently described genetically defined benign and malignant entities need be correctly diagnosed due to their special "targeted" therapeutic options and to further characterize their clinicopathological and biological properties in the future. These recent entities include aggressive epithelioid inflammatory myofibroblastic sarcoma (ALK-RANBP2-driven), malignant gastrointestinal neuroectodermal tumor (EWSR1-ATF1/CREB-related), NTRK-rearranged neoplasms, and, most recently, colorectal NUTM1-rearranged sarcomas. This review highlights the major clinicopathological features of gastrointestinal mesenchymal lesions in light of recent developments.

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.

Current surgical management of duodenal gastrointestinal stromal tumors

Duodenal gastrointestinal stromal tumors (D-GISTs) are uncommon mesenchymal tumors and are managed differently to common duodenal epithelial tumors. They may pose surgical challenges due to their unique but complex pancreaticoduodenal location of the gastrointestinal tract near the ampulla of Vater, pancreas, mesenteric blood vessels, biliary and pancreatic ducts. The surgical management of D-GISTs can be performed safely with good oncological outcomes provided an adequate resection margin can be achieved. The current surgical options of resectable primary D-GISTs varies with increasing complexity depending on the location, size and involvement of surrounding structures such as wedge resection with primary closure, segmental resection with small bowel anastomosis or radical pancreaticoduodenectomy. Laparoscopic approaches have been shown to be feasible and safe with good oncological outcomes in experienced hands. The minimally invasive techniques including robotic-assisted approach will likely increase in the future. D-GISTs have a prognosis comparable to gastric and other small bowel GISTs. However, the heterogeneity of different studies and the limited use of systemic tyrosine kinase inhibitor in the neoadjuvant and adjuvant settings may influence the overall survival of resected D-GISTs. The use of limited resection when condition allows is recommended due to lower surgical morbidity, less postoperative complications and better oncologic outcomes.

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.

A concealed inguinal presentation of a gastrointestinal stromal tumor (GIST): a case report and literature review

BACKGROUND

Gastrointestinal stromal tumor (GIST) can arise anyplace along the gastrointestinal (GI) tract. The uncommon tumor location in groin area is rarely reported.

CASE PRESENTATION

We herein reported a metastasized case presented as GI hemorrhage complicated with indirect hernia, and underwent tumor cytoreduction, herniorrhaphy and chemotherapy for jejunal GIST. The case was described consecutively based on the process of surgical management, with a good follow-up result. A literature review by searching similar case reports from two national medical databases was performed to summarize clinical features of such unusual presentation of GIST, which included hernia characteristics, short- and long-term outcomes of this disease. It showed GIST presenting as groin hernia was rarely reported and all available 11 cases suggested a primary tumor and required both tumor resection and hernia repair. The long-term results indicated 64.3% overall survival at 5 years after the incidental diagnosis.

CONCLUSIONS

Inguinal hernia is an extremely rare presentation of GIST, with limited case reports available in the literature. A radical involving tumor resection plus hernia repair is an optimal surgical approach for such uncommon condition. An adjuvant medication mounting on mutated KIT gene should be strictly followed for high risk cases.

Preservation of Organ Function in Locally Advanced Non-Metastatic Gastrointestinal Stromal Tumors (GIST) of the Stomach by Neoadjuvant Imatinib Therapy

Simple Summary

This study reports a single-center analysis of 55 patients with primary, locally advanced gastric GIST treated with imatinib mesylate (IM) preoperatively for a median of 10 months. The therapy yielded shrinkage of median tumor size from 113 mm to 62 mm. This facilitated 50 patients to undergo significantly less-extensive surgical procedures and resulted in a stomach preservation rate of 96%. The rate of R0 resections was 94% and was followed by a mean recurrence-free-survival time of 132 months with the median not reached. The approach was successful even for patients starting IM during an episode of upper gastrointestinal bleeding. Neoadjuvant IM therapy for locally advanced, non-metastatic gastrointestinal stromal tumors (GIST) of the stomach may play an important role in preserving organ function which might be important for IM plasma levels in an adjuvant or metastatic setting.

Abstract

Background: Neoadjuvant imatinib mesylate (IM) for advanced, non-metastatic gastrointestinal stromal tumors (GIST) of stomach is recommended to downsize the tumor prompting less-extensive operations and preservation of organ function. Methods: We analyzed the clinical-histopathological profile and oncological outcome of 55 patients (median age 58.2 years; range, 30–86 years) with biopsy-proven, cM0, gastric GIST who underwent IM therapy followed by surgery with a median follow-up of 82 months. Results: Initial median tumor size was 113 mm (range, 65–330 mm) and 10 patients started with acute upper GI bleeding. After a median 10 months (range, 2–21 months) of treatment, tumor size had shrunk to 62 mm (range, 22–200 mm). According to Response Evaluation Criteria In Solid Tumors version 1.0 and version 1.1 (RECIST 1.1), 39 (75%) patients had partial response and 14 patients had stable disease, with no progressive disease. At plateau response, 50 patients underwent surgery with an R0 resection rate of 94% and pathological complete response in 24%. In 12 cases (24%), downstaging allowed laparoscopic resection. The mean recurrence-free survival (RFS) was 123 months (95%CI; 99–147) and the estimated 5-year RFS was 84%. Conclusions: Neoadjuvant IM allowed stomach preservation in 96% of our patients with excellent long-term RFS, even when starting treatment during an episode of upper GI bleeding. Preservation of the stomach provides the physiological basis for the use of oral IM in the adjuvant or metastatic setting.

Laparoscopic vs. open surgery for gastrointestinal stromal tumors of esophagogastric junction: A multicenter, retrospective cohort analysis with propensity score weighting

Objective

Laparoscopic resection is increasingly performed for gastrointestinal stromal tumors (GISTs). However, the laparoscopic approach for GISTs located in the esophagogastric junction (EGJ-GIST) is surgically challenging. This study compares the efficacy of laparoscopic surgery and the open procedure for EGJ-GIST through the propensity score weighting (PSW) method.

Methods

Between April 2006 and April 2018, 1,824 surgical patients were diagnosed with primary gastric GIST at four medical centers in South China. Of these patients, 228 were identified as EGJ-GISTs and retrospectively reviewed clinicopathological characteristics, operative information, and long-term outcomes. PSW was used to create the balanced cohorts.

Results

PSW was carried out in laparoscopic and open-surgery cohorts according to year of surgery, sex, age, body mass index (BMI), tumor size, mitotic rates and recurrence risk. After PSW, 438 patients consisting of 213 laparoscopic (L group) and 225 open surgery (O group) patients were enrolled. After PSW, the following measures in the L group were superior to those in the O group: median operative time [interquartile range (IQR)]: 100.0 (64.5−141.5)vs. 149.0 (104.0−197.5) min, P<0.001; median blood loss (IQR): 30.0 (10.0−50.0)vs. 50.0 (20.0−100.0) mL, P=0.002; median time to liquid intake (IQR): 3.0 (2.0−4.0)vs. 4.0 (3.0−5.0) d, P<0.001; median hospital stay (IQR): 6.0 (4.0−8.0)vs. 7.0 (5.0−12.0) d, P<0.001; and postoperative complications (10.3%vs. 22.7%, P=0.001). The median follow-up was 55 (range, 2−153) months in the entire cohort. No significant differences were detected in either relapse-free survival (RFS) [hazard ratio (HR): 0.372, 95% confidence interval (95% CI): 0.072−1.910, P=0.236) or overall survival (OS) (HR: 0.400, 95% CI: 0.119−1.343, P=0.138) between the two groups.

Conclusions

Laparoscopic surgery for EGJ-GIST is associated with the advantages of shorter operative time, reduced blood loss, shorter time to liquid intake, and shorter length of stay, all without compromising postoperative outcomes and long-term survival.

Clinical features of multiple gastrointestinal stromal tumors: A pooling analysis combined with evidence and gap map

BACKGROUND

Multiple gastrointestinal stromal tumors (MGISTs) are a very rare type of gastrointestinal stromal tumor (GIST) and are usually observed in syndrome.

AIM

The paper aimed to describe the clinical and oncological features of MGISTs and to offer evidence for the diagnosis and treatment.

METHODS

Data of consecutive patients with MGISTs who were diagnosed at Peking University People’s Hospital (PKUPH) from 2008 to 2019 were retrospectively evaluated. Further, a literature search was conducted by retrieving data from PubMed, EMBASE, and the Cochrane library databases from inception up to November 30, 2019.

RESULTS

In all, 12 patients were diagnosed with MGISTs at PKUPH, and 43 published records were ultimately included following the literature review. Combined analysis of the whole individual patient data showed that female (59.30%), young (14.45%), and syndromic GIST (63.95%) patients comprised a large proportion of the total patient population. Tumors were mainly located in the small intestine (58.92%), and both CD117 and CD34 were generally positive. After a mean 78.32-mo follow-up, the estimated median overall survival duration (11.5 years) was similar to single GISTs, but recurrence-free survival was relatively poorer.

CONCLUSION

The clinical and oncological features are potentially different between MGISTs and single GIST. Further studies are needed to explore appropriate surgical approach and adjuvant therapy.

Robotic Wedge Resection for Unfavorably Located Gastric Gastrointestinal Stromal Tumors: Perioperative and Long-Term Oncological Outcomes

Background and Objectives: Robotic wedge resection for gastrointestinal stromal tumors (GISTs) located in the stomach offers remarkable advantages, especially for lesions in unfavorable places. Although promising, long-term oncological results associated with this surgical procedure are poorly represented in literature. We present our experience of robotic wedge resection with gastrotomy for challenging gastric GISTs, in terms of both surgical outcomes and long-term oncological results. Methods: From April 2014 to February 2020, all consecutive patients affected by unfavorably located gastric GISTs (based on the Privette/Al-Thani classification system) underwent robotic wedge resection. Clinicopathological, surgical, and long-term oncological results were retrospectively analyzed. Results: Seventeen patients underwent full-thickness gastric wedge resection with primary robot-sewn closure of the defect. In 64.7% of cases, the lesion was ≥5 cm in diameter. No conversion nor tumor rupture were recorded and complete R0 resection was achieved in all cases. Median hospital stay was 5 days (range 3-18). At a median follow-up of 46 months (range 7-67), the disease-free survival rate and the overall survival rate were 94.1% and 82.3%, respectively. Conclusions: Robotic wedge resection with gastrotomy and robotic-sewn suture is a safe and feasible procedure for GISTs located in unfavorable anatomic positions, without compromising oncological outcomes.

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.

A case of a diverticulum-like giant jejunal gastrointestinal stromal tumour presenting with intraperitoneal peritonitis due to rupture

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Diagnosing GIST is difficult due to the absence of clinical symptoms.

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GIST should be considered when sudden abdominal pain and a mass are present.

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We present a case of a GIST with partial resection and drainage surgery.

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Ensuring local resection and proper chemotherapy increases long-term survival.

Introduction

Early diagnosis of small intestinal gastrointestinal stromal tumours (GISTs) is difficult. These tumours often present with peritonitis and intraperitoneal bleeding due to rupture. We experienced a case of a tumor that grows to 12 cm asymptomatic.

Presentation of case

A 46-year-old man presented with sudden abdominal pain. Computed tomography revealed free air in the abdominal cavity, a 12-cm sized dilatation in the small intestine, and pooled residues. He was diagnosed with perforation of the gastrointestinal tract, and emergency surgery was performed. Inside the abdominal cavity, approximately 500 mL of bloody ascites was observed. A diverticulum-like mass measuring approximately 12-cm long was observed on the jejunum approximately 30 cm from the Treitz ligament. There was a large hematoma inside the mass, and perforation was recognised at the neck of the diverticulum. Partial resection of the jejunum and intraperitoneal drainage were performed. Immunohistochemistry revealed that the tumour was positive for KIT and CD34, and GIST was diagnosed. The patient was discharged on postoperative day 10 without significant complications. The patient did not relapse while taking imatinib as an adjuvant chemotherapy.

Discussion

Gastrointestinal stromal tumours are the most common mesenchymal tumours of the gastrointestinal tract and may undergo increased diverticulum-like growth, as seen in this case. Local resection and proper chemotherapy increase long-term survival, suppress tumour growth, and reduce the risk of relapse.

Conclusion

Diagnosing GIST can be difficult due to the absence of clinical symptoms. It is necessary to ensure local resection and careful long-term follow-up.

Recent Anti-platelet Therapy Revealing Underlying Undiagnosed Gastrointestinal Stromal Tumor in Otherwise Healthy Patient

Gastrointestinal stromal tumors (GIST) are uncommon tumors of the gastrointestinal (GI) tract that arise from primitive mesenchymal cells. Usually, GIST presents as chronic gastrointestinal symptoms or obscure gastrointestinal bleed. Not many cases have been reported in the literature with acute symptoms in the setting of recent aspirin use. We report a case of 70-year-old male otherwise healthy who presented to the hospital with the complaint of black tarry stool for the past two days after taking one tablet of aspirin once a day for two days. The patient underwent upper endoscopy which showed a moderate size polypoid mass in the gastric fundus. Initially, standard endoscopic biopsy was negative for malignancy, due to high suspicion for GIST, later the patient underwent upper endoscopic ultrasound with fine-needle aspiration which confirmed low-grade GIST.

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.

Quality of surgery and surgical reporting for patients with primary gastrointestinal stromal tumours participating in the EORTC STBSG 62024 adjuvant imatinib study

BACKGROUND

EORTC (European Organisation of Research and Treatment of Cancer) 62024 is a phase III randomised trial evaluating adjuvant imatinib in patients with gastrointestinal stromal tumours (GISTs) and no evidence of residual disease after surgery in 908 patients from 11 countries participated. As surgical treatment aspects (tumour rupture and incomplete resection) contribute to the risk of recurrence, the data of primary surgery were reviewed.

METHODS

The surgical record, local pathology report and a surgical questionnaire on details of the operation had to be completed when patients entered the study. Surgeons from 5 countries, covering 8 languages, reviewed the full set of data being available from 793 patients (87.3%).

RESULTS

A known GIST was the reason for surgery in only 58% of the cases, and 12% of the patients were treated as an emergency. The R0-resection rate was 87%. The extent of resection was local excision in 17%, segmental resection in 59%, full-organ resection in 11% and multivisceral resection in 11%, with lymphadenectomy performed in 24% of the patients. Shelling out of the tumour was performed in 9.7%, and the proportion of tumours removed in parts was higher in the endoscopy/laparoscopy group. The incidence of tumour rupture (representing M1) was 9%. The consistency between preoperative and intraoperative findings was 82%. The postoperative complication rate was 7.3%.

CONCLUSION

The standardisation of surgery in this study was inferior. Given the review data, 18% of the patients should not have participated in the trial. Quality of surgery and improperly reported intraoperative details might influence the trial results. A detailed surgical questionnaire filled out by the surgeon is mandatory before entering the patient in an adjuvant trial in GIST.

Short-term outcomes after duodenal surgery for mesenchymal tumors: a retrospective analysis from a single tertiary referral center

Duodenal resections are sometimes necessary for radical surgery. We analyzed technical aspects and post-operative outcomes in patients with RPS and GIST involving duodenum. We identified patients who underwent duodenal resection for RPS and GIST at our Institute between 2000 and 2016. Clinical, pathological and treatment variables were analyzed. Thirty patients were treated: 15 for GIST, 15 for RPS. Sixteen duodenal wedge resections (WR) and 14 segmental resections (SR) were performed. Multi-organ resection was frequently performed (63.4%). Median time to flatus was 3 days (range 1-6), to oral refeeding 4.5 (range 2-15). Overall postoperative morbidity rate was 53% (16/30): Clavien Dindo grade ≤ II: 10; duodenum-related complication rate was 33% (10/30), Clavien Dindo grade ≤ II: 9. Morbidity rates were higher in SR than WR. Duodenal resections for RPS and GIST have significant morbidity rate and whenever it is possible, WR is preferable to SR because of the lower morbidity rate.

Analysis of clinicopathological and immunohistochemical parameters and correlation of outcomes in gastrointestinal stromal tumors

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. We analyzed the clinicopathological features, resectability, immunohistochemical markers, and various factors predictive of disease recurrence and survival.

MATERIALS AND METHODS

Retrospective analysis of prospectively maintained database of GIST patients managed from 2005 to 2016 was done. Size, site, malignant potential, nuclear pleomorphism, histopathological variety, immunohistochemical markers, type of surgery, and adjuvant imatinib therapy were analyzed.

RESULTS

Ninety-two patients with GIST were analyzed. Immunohistochemistry showed positivity for c-kit (82.4%), DOG1 (75%), and PDGFR-α (79%). Among 16 patients with c-kit-negative tumors, 10 patients were positive for DOG1, PDGFR-α, or both. The most common primary site was stomach (44, 47.8%) followed by small bowel (17, 18.5%) and duodenum (14, 15.2%). Of 92 patients, 80 (87%) underwent R0 resection with organ sparing resection in 56 (70%) patients. Seventeen (21.3%) patients showed recurrence at a median follow-up of 6 years. Median and 5-year overall survival (OS) was 36 months (12-120) and 75%, respectively, and 5-year RFS was 81.8%. On univariate analysis, size, mitotic activity, malignant potential, and nuclear pleomorphism were predictors of recurrence. However, on multivariate analysis, only nuclear pleomorphism was significant.

CONCLUSIONS

GISTs had a wide spectrum of presentation, and immunohistopathological features with organ sparing resection were conceivable in maximum. Nuclear pleomorphism may be considered as an important variable to predict recurrence in addition to malignant potential of tumors.

The assessment of different risk classification systems for gastrointestinal stromal tumors (GISTs): the analytic results from the SEER database

BACKGROUND

Although various risk classification systems for GISTs have been proposed, the optimum one remains uncertain. In the present study, we compared the prognostic stratification of different risk classification systems for GIST patients.

METHODS

We reviewed those patients who were pathologically diagnosed with GISTs in the SEER database between 2009 and 2014. All patients were classified into different risk groups according to the NIH criteria, AFIP criteria and AJCC staging system, respectively. The prognostic differences between different risk groups were compared and clinicopathologic features were analyzed.

RESULTS

The prognosis of small intestinal GISTs was not significantly different from that of gastric GISTs. For gastric GIST patients, there was no significant prognostic difference between very low risk and low risk group according to the NIH and AFIP criteria. However, the prognostic stratification for two groups could be improved by the AJCC staging system. For small intestinal GIST patients, the prognostic difference between low risk and intermediate risk group was not stratified properly by the NIH and AFIP criteria. However, the prognostic difference between two groups could reach statistical significance according to the AJCC staging system. Unlike gastric GISTs, tumor size was not identified as an independent factor influencing the prognosis of small intestinal GISTs.

CONCLUSIONS

The AJCC staging system could provide a better prognostic stratification for GIST patients compared with the NIH and AFIP criteria, regardless of gastric or small intestinal tumor. However, primary tumor location and tumor size may be reconsidered and revised in the risk classification system.

Adjuvant therapy with imatinib in gastrointestinal stromal tumors (GISTs)-review and perspectives

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor of the gastrointestinal (GI) tract. Most of them (>75%) are driven by an oncogenic initiating event involving activating mutations of the genes encoding for tyrosine kinase, KIT or platelet derived growth factor receptor alpha (PDGFRA). Efficacy of the tyrosine kinase Inhibitor imatinib is now well established for advanced disease. For localized GISTs, 3 years treatment is the recommended adjuvant therapy for high risk patients. Whether a longer duration and selection of patients for this adjuvant therapy in localized GISTs remains is not yet established (PERSIST-5 study). Similarly, it will be important to further refine the definition of the population of GIST patients at high risk of relapse including molecular criteria (Annals of Oncology, ESMO guidelines 2018). This review aims to describe current knowledges on the issue of adjuvant therapy of primary GISTs in view of available results.

Performance of risk stratification systems for gastrointestinal stromal tumors: A multicenter study

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor type in the gastrointestinal system. Presently, various classification systems to prognosticate GISTs have been proposed.

AIM

To evaluate the application value of four different risk stratification systems for GISTs.

METHODS

Patients who were diagnosed with GISTs and underwent surgical resection at four hospitals from 1998 to 2015 were identified from a database. Risk of recurrence was stratified by the modified National Institute of Health (NIH) criteria, the Armed Forces Institute of Pathology (AFIP) criteria, the Memorial Sloan Kettering Cancer Center (MSKCC) prognostic nomogram, and the contour maps. Receiver operating characteristic (ROC) curves were established to compare the four abovementioned risk stratification systems based on the area under the curve (AUC).

RESULTS

A total of 1303 patients were included in the study. The mean age of the patients was 55.77 ± 13.70 yr; 52.3% of the patients were male. The mean follow-up period was 64.91 ± 35.79 mo. Approximately 67.0% the tumors were located in the stomach, and 59.5% were smaller than 5 cm; 67.3% of the patients had a mitotic count ≤ 5/50 high-power fields (HPFs). Thirty-four tumors ruptured before and during surgery. Univariate analysis demonstrated that tumor size > 5 cm (P < 0.05), mitotic count > 5/50 HPFs (P < 0.05), non-gastric location (P < 0.05), and tumor rupture (P < 0.05) were significantly associated with increased recurrence rates. According to the ROC curve, the AFIP criteria showed the largest AUC (0.754).

CONCLUSION

According to our data, the AFIP criteria were associated with a larger AUC than the NIH modified criteria, the MSKCC nomogram, and the contour maps, which might indicate that the AFIP criteria have better accuracy to support therapeutic decision-making for patients with GISTs.

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.

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.

TIPE2 acts as a biomarker for GIST risk category and suppresses the viability and invasiveness of GIST cells

Evaluating the risk category of gastrointestinal stromal tumors (GISTs) is crucial for predicting prognosis and choosing treatment strategies, and tumor metastasis usually represent poor prognosis. Tumor necrosis factor-alpha-induced protein 8-like 2 (TIPE2) is a novel described tumor suppressor. In the present study, TIPE2 expression was detected using a total of 96 human GIST specimens by immunohistochemistry. The effect of TIPE2 on proliferation and invasiveness of GIST cells and its related mechanisms were explored in vitro. It was found that TIPE2 expression was gradually decreased in accordance with GIST risk grades and negatively associated with tumor size, mitotic count and risk category. Moreover, TIPE2 was identified as a biomarker for evaluating the risk grade of GIST. TIPE2 markedly suppressed the viability, colony formation, migration and invasion of GIST cells. Furthermore, TIPE2 induced apoptosis and suppressed MMP-9 expression of GIST cells by targeting Rac1. In conclusion, these results indicate that TIPE2 plays a pivotal role in the progression of GIST. TIPE2 serves as a promising biomarker for evaluating GIST risk grade and a potential target for treatment of GIST.

Wide Surgical Margin Improves the Outcome for Patients with Gastrointestinal Stromal Tumors (GISTs)

Background

Surgical resection is still the main treatment for gastrointestinal stromal tumor (GIST), and R0 excision, regardless of surgical margins, is considered sufficient.

Methods

A cohort of 79 consecutive GIST cases treated at the Karolinska University Hospital, who were without metastasis at diagnosis and who had not received any pre-or postoperative treatment with tyrosine kinase inhibitors, was included. Surgical margins were evaluated at the time of surgery and classified as wide, marginal or intralesional. Time to local/peritoneal recurrence, distant metastasis, and survival were recorded. Cox regression analysis was used to investigate the association between surgical margin, and recurrence and survival.

Results

Local/peritoneal recurrence was diagnosed in 2/39 cases with wide margins, in 7/22 cases with marginal margins, and in 13/18 cases with intralesional surgery. Compared to wide margins this gives a hazard ratio of 6.8 (confidence interval 1.4–32.7) for marginal margins and 13.5 (3–61) for intralesional margins. In multivariate analysis, adjusting for size, site, and mitotic index, surgical margin remained an independent significant predictor of risk for recurrence. When classifying patients according to R0/R1 surgery, patients with R0 surgery showed longer time to peritoneal recurrence and better recurrence-free and disease-specific survival as compared to those with R1 resection. However, when excluding patients operated with wide surgical margin, no significant difference was observed.

Conclusion

Wide surgical margins are of significant prognostic importance, supporting the strategy of en bloc resection with good margin and careful handling of the tumor to avoid damaging the peritoneal surface in surgical resection of GIST.

Electronic supplementary material

The online version of this article (10.1007/s00268-018-4498-9) contains supplementary material, which is available to authorized users.

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.

Surgery for Gastrointestinal Stromal Tumors: State of the Art of Laparoscopic Resection and Surgery for M1 Tumors

BACKGROUND

The principles of surgery for primary gastrointestinal stromal tumor (GIST) are resection with clear margins without lymphadenectomy, thus enabling organ-preserving resection in many cases. Tumor rupture needs to be avoided, because it entails peritoneal sarcomatosis. Given these preconditions, there is a rationale for laparoscopic resection of primary GIST. In metastatic GIST, surgery cannot achieve cure, but constitutes an important cornerstone of treatment. Resection can be performed either for residual lesions in responding patients, for focally progressive lesions, or as palliative measure in generalized progression.

METHODS

Selective literature review.

RESULTS

There is ample evidence on laparoscopic resection of gastric GIST, but none from randomized trials. The studies show favorable perioperative outcomes and suggest adequate oncological results; however, a direct comparison to open resection is difficult. For surgery in M1 stages, survival outcomes are better for resection in generalized response than in focal progression. Perioperative morbidity is acceptable. Surgery in generalized progression does not prolong survival and bears relevant morbidity risks.

CONCLUSION

Laparoscopy seems an adequate surgical approach for primary gastric GIST, as long as the surgical principles relevant for this entity are respected. For other tumor sites, there is no sufficient evidence available. In M1 stages, selected patients may benefit from surgery. Survival differences between resection at different stages probably mirror the biology of the disease rather than the effect of the timing of the operation.

Standard Approach to Gastrointestinal Stromal Tumors - Differences between China and Europe

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. With the considerable research and application of molecular-targeted therapy for GISTs in the last two decades, GISTs have become a model of multidisciplinary oncological treatment. Although Western clinical guidelines are available for GISTs, such as those by the European Society of Medical Oncology (ESMO), the clinical situations in China are different from those in European countries. There are distinct differences between the clinical practice, diagnostic methods, surgical approach, and availability of new targeted agents in China and those in Europe. This review summarizes the Chinese GIST consensus guidelines compared to the European ones, which may provide an optimal approach to the diagnosis and management of GIST patients.

Surgical treatment of gastrointestinal stromal tumors of the duodenum: a literature review

Background

Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal tumours in the digestive tract. The duodenal GIST (dGIST) is the rarest subtype, representing only 4-5% of all GIST, but up to 21% of the resected ones. The diagnostic and therapeutic management of dGIST may be difficult due to the rarity of this tumor, its anatomical location, and the clinical behavior that often mimic a variety of conditions; moreover, there is lack of consent for their treatment. This study has evaluated the scientific literature to provide consensus on the diagnosis of dGIST and to outline possible options for surgical treatment.

Methods

An extensive research has been carried out on the electronic databases MEDLINE, Scopus, EMBASE and Cochrane to identify all clinical trials that report an event or case series of dGIST.

Results

Eighty-six studies that met the inclusion criteria were identified with five hundred forty-nine patients with dGIST: twenty-seven patients were treated with pancreatoduodenectomy and ninety-six with only local resection (segmental/wedge resections); in four hundred twenty-six patients it is not possible identify the type of treatment performed (pancreatoduodenectomy or segmental/wedge resections).

Conclusions

dGISTs are a very rare subset of GISTs. They may be asymptomatic or may involve symptoms of upper GI bleeding and abdominal pain at presentation. Because of the misleading clinical presentation the differential diagnosis may be difficult. Tumours smaller than 2 cm have a low biological aggressiveness and can be followed annually by endoscopic ultrasound. The biggest ones should undergo radical surgical resection (R0). In dGIST there is no uniformly adopted surgical strategy because of the low incidence, lack of experience, and the complex anatomy of the duodenum. Therefore, individually tailored surgical approach is recommended. R0 resection with 1-2 cm clear margin is required. Lymph node dissection is not recommended due to the low incidence of lymphatic metastases. Tumor rupture should be avoided.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

A cohort study of prognostic factors associated with recurrence or metastasis of gastrointestinal stromal tumor (GIST) of stomach

Background

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract. The major risk factors of recurrence and metastasis are mitotic index and tumor size. This study investigates the risk of recurrence and metastasis in solely gastric GIST. The primary outcome is to evaluate risk of recurrence and metastasis. The secondary outcome is to analyse survival rates of patients who have recurrence and metastasis after curative resection.

Method

A cohort of patients who underwent curative resection of gastric GIST between January 2006 to December 2016 was reviewed. The diagnosis was confirmed with positive CD34, DOG1 or KIT (CD117) immunohistochemistry. Risk factors of recurrence and metastasis were analyzed.

Results

Sixty-eight patients who received curative resection and diagnosed as gastric GIST were included in this study. Twenty (29.41%) had recurrence or metastasis. The median follow up time was 31.95 months. The mostcommon type of surgery was partial gastric resection. There were statistically-significant differences between mitotic index 6 HPF or 6 HPF in tumor size 0-5 cm, 5-10 cm and 10 cm and the risk of recurrence or metastasis (p-value 0.036). In tumors sized 6-10 cm, patients with mitotic index 6 HPF had longer survival than patients with mitotic index 6 HPF (p-value 0.0147).

Conclusion

The factor that determines the outcome of recurrence or metastasis in solely gastric GIST is high mitotic index count. Patients who have abdominal pain may be suspected as advanced disease. The type of operation and tumor size are not associated with recurrence or metastasis.

•

The factor that determines the outcome of recurrence or metastasis in gastric GIST is high mitotic index count more than 6.

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Patients who have abdominal pain may be suspected as advanced disease.

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The tumor size are not associated with recurrence or metastasis.

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The overall survival did not depend on the tumor size, in contrast, the overall survival depends on the mitotic index.