Time to Definitive Failure to the First Tyrosine Kinase Inhibitor in Localized GI Stromal Tumors Treated With Imatinib As an Adjuvant: A European Organisation for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group Intergroup Randomized Trial in Collaboration With the Australasian Gastro-Intestinal Trials Group, UNICANCER, French Sarcoma Group, Italian Sarcoma Group, and Spanish Group for Research on Sarcomas

English version of Japanese Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) issued by the Japan Society of Clinical Oncology

The Japan Society of Clinical Oncology Clinical Practice Guidelines 2022 for gastrointestinal stromal tumor (GIST) have been published in accordance with the Minds Manual for Guideline Development 2014 and 2017. A specialized team independent of the working group for the revision performed a systematic review. Since GIST is a rare type of tumor, clinical evidence is not sufficient to answer several clinical and background questions. Thus, in these guidelines, we considered that consensus among the experts who manage GIST, the balance between benefits and harms, patients' wishes, medical economic perspective, etc. are important considerations in addition to the evidence. Although guidelines for the treatment of GIST have also been published by the National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO), there are some differences between the treatments proposed in those guidelines and the treatments in the present guidelines because of the differences in health insurance systems among countries.

The impact of contour maps on estimating the risk of gastrointestinal stromal tumor recurrence: indications for adjuvant therapy: an analysis of the Kinki GIST registry

INTRODUCTION

Contour maps enable risk classification of GIST recurrence in individual patients within 10 postoperative years. Although contour maps have been referred to in Japanese guidelines, their usefulness and role in determining indications for adjuvant therapy is still unclear in Japanese patients. The aims of this study are to investigate the validity of contour maps in Japanese patients with GIST and explore the new strategy for adjuvant therapy.

MATERIALS AND METHODS

A total of 1426 Japanese GIST patients who were registered to the registry by the Kinki GIST Study Group between 2003 and 2012 were analyzed. Patients who had R0 surgery without perioperative therapy were included in this study. The accuracy of contour maps was validated.

RESULTS

Overall, 994 patients have concluded this study. Using contour maps, we validated the patients. The 5-year recurrence-free survival rates of patients within the GIST classification groups of 0-10%, 10-20%, 20-40%, 40-60%, 60-80%, 80-90%, and 90-100% were 98.1%, 96.6%, 92.3%, 48.0%, 37.3%, 41.0% and 42.4%, respectively. We confirmed that this classification by contour maps was well reflected recurrence prediction. Further, in the high-risk group stratified by the modified National Institutes of Health consensus criteria (m-NIHC), the 10-year RFS rate was remarkably changed at a cutoff of 40% (0-40% group vs. 40-100% group: 88.7% vs. 50.3%, p < 0.001).

CONCLUSION

Contour maps are effective in predicting individual recurrence rates. And it may be useful for the decision of individual strategy for high-risk patients combined with m-NIHC.

Advanced and Metastatic Gastrointestinal Stromal Tumors Presenting With Surgical Emergencies Managed With Surgical Resection: A Case Series

Advanced and metastatic gastrointestinal stromal tumors (GISTs) presenting with surgical emergencies are rare. Neoadjuvant imatinib being the treatment of choice for non-metastatic advanced disease with a proven role in downstaging the disease may not be feasible in patients presenting with bleeding and obstruction. We present a case series with retrospective analysis of a prospectively maintained database of patients with advanced and metastatic GISTs presenting with surgical emergencies. Clinical characteristics, imaging and endoscopic findings, surgical procedures, histological findings, and outcomes in these patients were studied. Four patients were included in this case series, with three males and one female (age range: 24-60 years). Two patients presented with melena; one with hemodynamic instability despite multiple blood transfusions underwent urgent exploratory laparotomy for bleeding gastric GIST, while the other underwent surgical exploration after careful evaluation given the recurrent, metastatic disease with a stable metabolic response on six months of imatinib. One patient with metastatic jejunal GIST who presented with an umbilical nodule and intestinal obstruction was given a trial of non-operative management for 72 hours, but due to non-resolution of obstruction, segmental jejunal en bloc resection with the dome of the urinary bladder with reconstruction and metastasectomy was needed. The patient with advanced gastric GIST who presented with gastric outlet obstruction was resuscitated, and an attempt of endoscopic naso-jejunal tube placement was tried, which failed, and exploration was needed. The mean length of hospital stay was 7.5 days. Histopathological examination confirmed GIST in all four patients with microscopic negative resection margins. All patients were started on imatinib with dose escalation to 800 mg in the patient with recurrent and metastatic disease; however, the patient with bleeding gastric GIST experienced severe adverse effects of imatinib and discontinued the drug shortly. All four patients are disease-free on follow-ups of 15 months, 48 months for the patient with advanced non-metastatic disease, and six and 24 months for the patients with metastatic disease. In the era of tyrosine kinase inhibitor (TKI) therapy for advanced and metastatic disease, upfront surgery is usually reserved for surgical emergencies only. Surgical resection, the cornerstone for the treatment of resectable GIST, may also be clinically relevant in metastatic settings, although it requires a careful and individualized approach.

Surgical management of a locally advanced jejunal stromal tumor: A case report of a challenging condition

INTRODUCTION AND IMPORTANCE

Locally advanced jejunal stromal tumors stand as a captivating and relatively rare entity, garnering attention for several reasons. Their inaccessible location by conventional endoscopy poses a diagnostic challenge. Further, treatment decisions necessitate a multidisciplinary approach, compounded by the absence of high-level evidence studies.

CASE PRESENTATION

A 54-year-old patient was admitted to our surgical department with abdominal pain and chronic anemia. Abdominal CT imaging confirmed the presence of a non-metastatic sizable jejunal tumor. The patient underwent laparotomy, revealing a locally advanced jejunal tumor contracting the ileum and the ascending colon. A monobloc oncological resection was performed, followed by the restoration of digestive continuity. Anatomopathological analysis delineated a locally advanced Stromal Tumor with a high risk of recurrence. The patient underwent a course of tyrosine kinase inhibitors for 3 years, with no reported recurrence during the subsequent 3-year follow-up.

DISCUSSION

Locally advanced jejunal stromal tumors are rare. Most patients present with unspecific symptoms. Diagnosis remains challenging due to their intricate anatomical location. Decisions regarding management must be deliberated within a multidisciplinary framework, tailored to each patient's unique characteristics. While combined therapeutic modalities have demonstrated efficacy in recent studies, prudence is advised given the heightened incidence of both short and long-term complications.

CONCLUSION

In the absence of randomized controlled trials, the management of locally advanced jejunal stromal tumors underscores the imperative of multidisciplinary collaboration in treatment deliberations. A wide, sometimes mutilating excision is only permissible if it is complete.

Fear, anxiety and depression in gastrointestinal stromal tumor (GIST) patients in the Netherlands: Data from a cross-sectional multicenter study

Background

This study aims to (1) investigate the prevalence of anxiety, depression and severe fear of cancer recurrence or progression in gastrointestinal stromal tumor (GIST) patients treated in a curative or palliative setting, (2) compare their prevalence with a norm population, (3) identify factors associated with anxiety, depression and severe fear, and (4) study the impact of these psychological symptoms on health-related quality of life (HRQoL).

Methods

In a cross-sectional study, GIST patients completed the Hospital Anxiety and Depression Scale, Cancer Worry Scale, and EORTC QLQ-C30.

Results

Of the 328 patients, 15% reported anxiety, 13% depression, and 43% had severe fear. Anxiety and depression levels were comparable between the norm population and patients in the curative setting, but significantly higher for patients in the palliative setting. Having other psychological symptoms was associated with anxiety, while current TKI treatment and anxiety were associated with depression. Severe fear was associated with age, female sex, palliative treatment setting, anxiety, and GIST-related concerns.

Conclusion

GIST patients treated in a palliative setting are more prone to experience psychological symptoms, which can significantly impair their HRQoL. These symptoms deserve more attention in clinical practice, in which regular screening can be helpful, and appropriate interventions should be offered.

Adjuvant Targeted Therapy in Solid Cancers: Pioneers and New Glories

Targeted therapy (TT) has revolutionized cancer treatment, successfully applied in various settings. Adjuvant TT in resected early-stage gastrointestinal stromal tumors (GIST), melanoma, non-small cell lung cancer (NSCLC), and breast cancer has led to practice-changing achievements. In particular, standard treatments include BRAF inhibitors for melanoma, osimertinib for NSCLC, hormone therapy or HER2 TT for breast cancer, and imatinib for GIST. Despite the undeniable benefit derived from adjuvant TT, the optimal duration of TT and the appropriate managing of the relapse remain open questions. Furthermore, neoadjuvant TT is emerging as valuable, particularly in breast cancer, and ongoing studies evaluate TT in the perioperative setting for early-stage NSCLC. In this review, we aim to collect and describe the large amount of data available in the literature about adjuvant TT across different histologies, focusing on epidemiology, major advances, and future directions.

Cost Evaluation Analysis of Genetic Testing and Tailored Adjuvant Imatinib in Patients With Resected High-Risk GI Stromal Tumors: The Brazilian Perspective

PURPOSE

Mutations of the KIT gene are the molecular hallmark of most GI stromal tumors (GISTs). Imatinib has revolutionized GIST treatment. Adjuvant imatinib for 3 years is the standard of care for high-risk resected GIST. However, the GIST molecular biologic profile has found different responses to this approach. Despite this, genetic testing at diagnosis is not a routine and empirical adjuvant imatinib remains the rule. Barriers to genetic profiling include concerns about the cost and utility of testing. This analysis aims to determine whether targeted genetic testing reduces costs as an ancillary tool for a limited-resource scenario instead of adjuvant empirical imatinib in patients with resected high-risk GIST.

METHODS

The cost evaluation analysis of molecular testing for GIST was based on the Cost of Preventing an Event (COPE), considering the Number Needed to Treat and the costs of each test compared with the cost of 3-year empirical adjuvant imatinib and real treatment costs (median number of cycles) from the public and private Brazilian Healthcare System's perspective. The analysis compared the costs of the molecular tests (broad next-generation sequencing [NGS], GS Infinity DNA/RNA assay, and targeted NGS: GS Focus GIST and the Fleury GIST Tumor DNA sequencing panel), costs of drug acquisition, considering discounts (imatinib mesylate and Glivec), and the costs of supportive care.

RESULTS

In both scenarios, public and private, regardless of the use of imatinib or Glivec, tailoring adjuvant treatment reduced costs, irrespective of the number of cycles. The only exception was the combination of the broad NGS test and imatinib in the Public Healthcare System.

CONCLUSION

The molecularly tailored adjuvant imatinib reduced costs considering the COPE of available NGS tests for both the public and private Brazilian health care systems.

Utilization of Neoadjuvant Therapy in Gastrointestinal Stromal Tumors of the Stomach: Analysis of the 2006-2018 National Cancer Database

BACKGROUND

Neoadjuvant tyrosine kinase inhibitor (TKI) therapy has reduced tumor burden and improved survival in both primary and recurrent gastrointestinal stromal tumors (GISTs). However, no clear guidelines exist on optimal patient selection for neoadjuvant therapy (NAT). Our aim was to analyze factors and outcomes associated with the therapeutic sequence of TKI therapy before and/or after surgery for gastric GISTs.

METHODS

We performed a retrospective study of patients surgically treated for a gastric GIST utilizing the 2006-2018 National Cancer Database. We examined demographic, clinical, and pathological characteristics associated with NAT versus adjuvant therapy (AT) using logistic regression.

RESULTS

Of the 3732 patients, 20.4% received NAT and 79.6% had AT. Among patients receiving therapy, NAT significantly increased over our study period (12% to 30.7%). A majority of the AT group received a partial gastrectomy (77.9%) compared with the NAT group who received more near-total/total gastrectomy or gastrectomy with en bloc resection (p < 0.001). In a multivariable model, patients were more likely to receive NAT when insured (private, aOR: 2.37, 95% CI: 1.31-4.29), treated at an academic/research program (aOR: 1.83, 95% CI: 1.49-2.56), had tumors located in the proximal stomach (aOR: 1.40, 95% CI: 1.06-1.86), tumor size > 10 cm (aOR: 1.88, 95% CI: 1.41-2.51), and received near-total/total gastrectomy (aOR: 1.81, 95% CI: 1.42-2.29). There were no differences in outcomes.

CONCLUSION

NAT for gastric GIST has increased in utilization. NAT was used in patients with larger tumors and who underwent more extensive resection. Despite these factors, outcomes were similar to patients receiving only AT. More studies are required to determine the therapeutic sequence for gastric GISTs.

SEOM-GEIS clinical guideline for gastrointestinal stromal tumors (2022)

Gastrointestinal stromal tumor (GIST) is the most common malignant neoplasm of mesenchymal origin, and a paradigmatic model for a successful rational development of targeted therapies in cancer. The introduction of tyrosine kinase inhibitors with activity against KIT/PDGFRA in both localized and advanced stages has remarkably improved the survival in a disease formerly deemed resistant to all systemic therapies. These guidelines are elaborated by the conjoint effort of the Spanish Society of Medical Oncology (SEOM) and the Spanish Sarcoma Research Group (GEIS) and provide a multidisciplinary and updated consensus for the diagnosis and treatment of GIST patients. We strongly encourage that the managing of these patients should be performed within multidisciplinary teams in reference centers.

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.

Evaluation of Systemic Treatment Options for Gastrointestinal Stromal Tumours

Gastrointestinal stromal tumours (GIST) are the most common mesenchymal tumours of the gastrointestinal tract. Surgical treatment is recommended for the majority of localised GIST, while systemic treatment is the cornerstone of management for metastatic or unresectable disease. While a three-year regimen of imatinib is the standard of care in the adjuvant setting, there is no precise recommendation for the duration of neoadjuvant treatment, where imatinib is usually given between 4 and 12 months. Continuous treatment with imatinib at a dose of 400 mg once per day is recommended for most patients with unresectable or metastatic GIST in the first line. An exception is represented by patients with tumours harbouring the imatinib-insensitive PDGFRA D842V mutation who would be better treated with avapritinib. Targeted therapies are also recommended in the presence of NTRK rearrangements and BRAF mutations, although limited data are available. While an increase in the dose of imatinib to 800 mg is an option for the second line, sunitinib is usually considered the standard of care. Similar outcomes were reported for ripretinib in patients with tumours harbouring KIT exon 11 mutation, with significantly fewer side effects. Regorafenib and ripretinib are the standards of care in the third and fourth lines, respectively. The recent development of various systemic treatment options allows for a more personalised approach based on the molecular profile of the GIST, patient characteristics, and the profile of medications' adverse events. A multidisciplinary approach is paramount since combining systemic treatment with locoregional treatment options and supportive care is vital for long-term survival.

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.

Molecular Advances in the Treatment of Advanced Gastrointestinal Stromal Tumor

Most gastrointestinal stromal tumors (GIST) are driven by activating mutations in Proto-oncogene c-KIT (KIT) or PDGFRA receptor tyrosine kinases (RTK). The emergence of effective therapies targeting these mutations has revolutionized the management of advanced GIST. However, following initiation of first-line imatinib, a tyrosine kinase inhibitor (TKI), nearly all patients will develop resistance within 2 years through the emergence of secondary resistance mutations in KIT, typically in the Adenosine Triphosphate (ATP)-binding site or activation loop of the kinase domain. Moreover, some patients have de novo resistance to imatinib, such as those with mutations in PDGFRA exon 18 or those without KIT or PDGFRA mutation. To target resistance, research efforts are primarily focused on developing next-generation inhibitors of KIT and/or PDGFRA, which can inhibit alternate receptor conformations or unique mutations, and compounds that impact complimentary pathogenic processes or epigenetic events. Here, we review the literature on the medical management of high-risk localized and advanced GIST and provide an update on clinical trial approaches to this disease.

Molecular Mechanisms of Gastrointestinal Stromal Tumors and Their Impact on Systemic Therapy Decision

Gastrointestinal stromal tumors (GISTs) are soft tissue sarcomas that mostly derive from Cajal cell precursors. They are by far the most common soft tissue sarcomas. Clinically, they present as gastrointestinal malignancies, most often with bleeding, pain, or intestinal obstruction. They are identified using characteristic immunohistochemical staining for CD117 and DOG1. Improved understanding of the molecular biology of these tumors and identification of oncogenic drivers have altered the systemic treatment of primarily disseminated disease, which is becoming increasingly complex. Gain-of-function mutations in KIT or PDGFRA genes represent the driving mutations in more than 90% of all GISTs. These patients exhibit good responses to targeted therapy with tyrosine kinase inhibitors (TKIs). Gastrointestinal stromal tumors lacking the KIT/PDGFRA mutations, however, represent distinct clinico-pathological entities with diverse molecular mechanisms of oncogenesis. In these patients, therapy with TKIs is hardly ever as effective as for KIT/PDGFRA-mutated GISTs. This review provides an outline of current diagnostics aimed at identifying clinically relevant driver alterations and a comprehensive summary of current treatments with targeted therapies for patients with GISTs in both adjuvant and metastatic settings. The role of molecular testing and the selection of the optimal targeted therapy according to the identified oncogenic driver are reviewed and some future directions are proposed.

Evidence for the Current Management of Soft-tissue Sarcoma and Gastrointestinal Stromal Tumors and Emerging Directions

Soft-tissue sarcoma (STS) is not a single entity but, rather, a family of diseases with differing biologic behaviors and anatomic site- and histotype-specific responses to treatment. Whereas surgery remains the mainstay of treatment of primary, localized disease, evolving evidence is establishing the role of multimodality treatment of these tumors. This article summarizes prospective evidence to date informing our treatment of STS. Key future directions will include advancing our understanding of fundamental tumor biology and mechanisms of response and recurrence, as well as defining the optimal provision of regional, systemic, and targeted therapies, including the role of immunotherapy. Ongoing global collaborations will be integral to progress in treating these rare tumors.

Large esophageal gastrointestinal stromal tumors resected thoracoscopically after oral imatinib therapy: a report of two cases

Esophageal gastrointestinal stromal tumors (GISTs) are very rare, accounting for 2–5% of all GISTs. As with other GISTs, the principle of surgical treatment is complete resection with negative margins. In addition to biological grades of GISTs itselves, local recurrence due to capsular damage is a known risk. We describe two cases of massive esophageal GISTs that were successfully resected thoracoscopically after 2 months administration of 400 mg imatinib, with some discussion of the literature. Case 1, the patient was a 51-years-old man. After treated with 400 mg of imatinib as preoperative chemotherapy for 2 months, we performed surgery that included right thoracoscopic subtotal esophagectomy, gastric tube reconstruction, and jejunostomy. The resection specimen and histopathology were esophageal GIST-LtMtAeG, 110 × 95 mm. The postoperative course was uneventful, and was discharged on postoperative day 14. The patient has been recurrence free for 11 months postoperatively. Case 2, the patient was a 70-years-old man. After treated with 400 mg of imatinib as preoperative chemotherapy for 2 months, we performed surgery that included right thoracoscopic subtotal esophagectomy, gastric tube reconstruction, and jejunostomy. The resection specimen and histopathology were esophageal GIST-LtAeG, 90 × 52 mm. The postoperative course was uneventful, and was discharged on postoperative day 14. The patient has been recurrence free for 9 months postoperatively.

Management of pelvic sarcoma

Pelvic sarcomas are a rare and heterogenous group of tumors divided into two groups: soft tissue sarcomas and bone sarcomas. Soft tissue sarcomas of the pelvis include most commonly liposarcoma, leiomyosarcoma, gastrointestinal stromal tumors, malignant peripheral nerve sheath tumors, and solitary fibrous tumors. Bone sarcomas of the pelvis most commonly include osteosarcoma and chondrosarcoma. Multidisciplinary treatment at a center experienced in the treatment of sarcoma is essential. Management is dictated by histologic type and grade. Surgical resection with wide margins is the cornerstone of treatment for pelvic sarcomas, although this is often challenging due to anatomic constraints of the pelvis. Multimodal treatment is critical due to the high risk of local recurrence in the pelvis.

Is minimally invasive surgery for large gastric GIST actually safe? A comparative analysis of short- and long-term outcomes

INTRODUCTION

While minimally invasive surgery (MIS) is frequently utilized to remove small gastric gastrointestinal stromal tumors (GIST), MIS surgery for tumors ≥ 5 cm is currently not endorsed by national guidelines as standard of care due to concerns of safety and inferior oncologic outcomes. Hence this study investigates the perioperative and long-term outcomes of MIS for T3 gastric GIST measuring 5-10 cm.

METHODS

The National Cancer Database (NCDB) 2017 was queried for gastric GIST measuring 5-10 cm or T3 category. Inclusion criteria were known: stage, size, comorbidities, grade, lymphovascular invasion, type of surgery, approach, conversion info, margin status, mitotic rate, neoadjuvant and adjuvant treatment, hospital stay, readmission, 30- and 90-day mortality, complete follow-up, type of institution, and hospital gastric surgery case volume. Binary logistic regression, linear regression models, and Kaplan-Meier survival analysis were used.

RESULTS

In 3765 patients, mean tumor size was 67.3 mm; 26.3% MIS; and 73.8% open. Median hospital stay was shorter for MIS (4.77 vs 7.04 days, p < 0.001). There was no significant difference in incidence of R1 margins [2.9% MIS vs. 3.1% open (p = 0.143)], unplanned readmission [2.9% MIS and 4.1% open (OR 0.474 p = 0.025)], 30-day mortality [0.5% MIS vs 1.2% open (OR 0.325, p = 0.031)], and 90-day mortality [0.9% MIS vs 2.1% open (OR 0.478 p = 0.036)]. Cox regression models for OS showed no difference in survival (p = 0.137, HR 0.808).

CONCLUSION

This analysis provides substantial evidence that MIS for gastric GIST ≥ 5-10 cm may not only offer improved postoperative morbidity but also oncologic safety. Moreover, as both approaches lead to similar long-term survival, national guidelines may need to incorporate this new information.

Systemic Therapy for Gastrointestinal Stromal Tumor: Current Standards and Emerging Challenges

Gastrointestinal stromal tumor (GIST), though rare, is the most common mesenchymal tumors of the gastrointestinal tract. KIT or PDGFRα mutation plays as an oncogenic driver in the majority of GISTs. Surgical resection is the only curative treatment for localized disease. The discovery of imatinib with promising anti-tumor effect and successive tyrosine kinase inhibitors (TKI), including second-line sunitinib and third-line regorafenib, revolutionized the management of advanced and metastatic GIST over the past two decades. Recently, ripretinib and avapritinib were approved for the fourth line setting and for PDGFRA exon 18-mutant GIST in first-line setting, respectively. Despite multi-line TKIs exerted ability of disease control, drug resistance remained an obstacle for preventing rapid disease progression. Experimental TKIs or novel therapeutic targets may further improve treatment efficacy. Immune checkpoint inhibitors such as anti-programmed cell death protein-1 (PD1) and anti-CTL-associated antigen 4 (CTLA-4) showed moderate response in early phase trials composed of heavily pretreated patients. KIT/PDGFRα wild-type GISTs are generally less sensitive to imatinib and late-line TKIs. Recent studies demonstrated that targeting fibroblast growth factor receptor signaling may be a potential target for the wild-type GISTs.

Relevant Trials Update in Sarcomas and Gastrointestinal Stromal Tumors: What Surgeons Should Know

In the past few years, the sarcoma community has successfully completed several trials in patients with soft tissue sarcoma (STS) or gastrointestinal stromal tumor (GIST). The current review summarizes recently reported relevant trials or trial updates investigating radiotherapy, chemotherapy, and targeted therapy in patients with localized extremity or superficial trunk STS, retroperitoneal sarcoma, and GIST.

Neoadjuvant tyrosine kinase inhibitor therapy for patients with gastrointestinal stromal tumor: A propensity-matched analysis

BACKGROUND

Tyrosine kinase inhibitor (TKI) neoadjuvant therapy (NAT) is often given in gastrointestinal stromal tumors (GISTs) with the goal to facilitate less morbid resections and improve oncologic outcomes; however, the use of NAT for GIST is poorly studied.

METHODS

We reviewed patients with resected nonmetastatic GIST from 2003 to 2019. Overall (OS) and recurrence-free survival (RFS) were assessed with Kaplan-Meier modeling. We performed 1:1 propensity-matching for relevant clinicopathologic variables for receipt of NAT.

RESULTS

We identified 254 patients. Propensity 1:1 matching resulted in 33 patients per group. The median follow-up was 77 months with no difference in 10-year OS (68% vs. 73%), 5-year RFS (13% vs. 10%), or median RFS (24 vs. 27 months) for patients treated with NAT versus upfront resection (all P > 0.9). Hospital length-of-stay (both median 7 days) and Clavien-Dindo ≥ III complications (12% vs. 3%) were not different between groups (both P ≥ 0.35).

DISCUSSION

TKI NAT can be used to facilitate resection in select patients with surgically higher-risk GIST, however it does not result in an independent oncologic benefit.

Cost-Effectiveness Analysis of Tyrosine Kinase Inhibitors in Gastrointestinal Stromal Tumor: A Systematic Review

Background: The introduction of tyrosine kinase inhibitor (TKI) therapy has dramatically improved the clinical effectiveness of patients with locally advanced and/or metastatic gastrointestinal stromal tumors (GIST), and this systematic review was conducted aiming at the cost-effectiveness analysis of TKIs in GIST.

Methods: A thorough literature search of online databases was performed, using appropriate terms such as “gastrointestinal stromal tumor or GIST,” “cost-effectiveness,” and “economic evaluation.” Data extraction was conducted independently by two authors, and completeness of reporting and quality of the evaluation were assessed. The systematic review was conducted following the PRISMA statement.

Results: Published between 2005 and 2020, 15 articles were incorporated into the systematic review. For advanced GIST, imatinib followed by sunitinib was considered cost-effective, and regorafenib was cost-effective compared with imatinib re-challenge therapy in the third-line treatment. For resectable GIST, 3-year adjuvant imatinib therapy represented a cost-effective treatment option. The precision medicine-assisted imatinib treatment was cost-effective compared with empirical treatment.

Conclusion: Although identified studies varied in predicted costs and quality-adjusted life years, there was general agreement in study conclusions. More cost-effectiveness analysis should be conducted regarding more TKIs that have been approved for the treatment of GIST.

Systematic Review Registration:https://www.crd.york.ac.uk/, PROSPERO: CRD42021225253.

Adjuvant Imatinib in Patients with GIST Harboring Exon 9 KIT Mutations: Results from a Multi-institutional European Retrospective Study

PURPOSE

The effect of high-dose imatinib (800 mg/day) on survival in the adjuvant treatment of patients with resected KIT exon 9-mutated gastrointestinal stromal tumors (GIST) is not established. Here, the association of dose and other clinicopathologic variables with survival was evaluated in a large multi-institutional European cohort.

EXPERIMENTAL DESIGN

Data from 185 patients were retrospectively collected in 23 European GIST reference centers. Propensity score matching (PSM) and inverse-probability of treatment weighting (IPTW) were used to account for confounders. Univariate and multivariate unweighted and weighted Cox proportional hazard regression models were estimated for relapse-free survival (RFS), modified-RFS (mRFS) and imatinib failure-free survival (IFFS). Univariate Cox models were estimated for overall survival.

RESULTS

Of the 185 patients, 131 (70.8%) received a starting dose of 400 mg/d and the remaining 54 (29.2%) a dose of 800 mg/d. Baseline characteristics were partially unbalanced, suggesting a potential selection bias. PSM and IPTW analyses showed no advantage of imatinib 800 mg/d. In the weighted multivariate Cox models, high-dose imatinib was not associated with the survival outcomes [RFS: hazard ratio (HR), 1.24; 95% confidence interval (CI), 0.79-1.94; mRFS: HR, 1.69; 95% CI, 0.92-3.10; IFFS: HR, 1.35; 95% CI, 0.79-2.28]. The variables consistently associated with worse survival outcomes were high mitotic index and nongastric tumor location.

CONCLUSIONS

In this retrospective series of patients with KIT exon 9-mutated GIST treated with adjuvant imatinib, a daily dose of 800 mg versus 400 mg did not show better results in terms of survival outcomes. Prospective evaluation of the more appropriate adjuvant treatment in this setting is warranted.

Health-Related Quality of Life and Side Effects in Gastrointestinal Stromal Tumor (GIST) Patients Treated with Tyrosine Kinase Inhibitors: A Systematic Review of the Literature

BACKGROUND

The introduction of tyrosine kinase inhibitors (TKIs) has revolutionized the treatment of gastrointestinal stromal tumors (GISTs), resulting in a substantial gain in median overall survival. Subsequently, health-related quality of life (HRQoL) has become more relevant. Here, we systematically review the available literature on HRQoL issues and side effects of different TKIs registered for the treatment of GIST.

METHODS

A search through five databases was performed. Full reports in English describing HRQoL outcomes and/or side effects in GIST patients on TKI therapy were included.

RESULTS

A total of 104 papers were included; 13 studies addressed HRQoL, and 96 studies investigated adverse events. HRQoL in patients treated with imatinib, regorafenib, and ripretinib remained stable, whereas most sunitinib-treated patients reported a decrease in HRQoL. Severe fatigue and fear of recurrence or progression were specifically assessed as HRQoL issues and had a negative impact on overall HRQoL as well as psychological and physical well-being. The majority of studies focused on physician-reported side effects. Nearly all GIST patients treated with a TKI experienced at least one adverse event, mostly mild to moderate.

CONCLUSIONS

Despite the fact that almost all patients treated with a TKI experienced side effects, this did not seem to affect overall HRQoL during TKI therapy. In daily practice, it are the side effects that hamper a patient's HRQoL resulting in treatment adjustments, suggesting that the reported side effects were underestimated by physicians, or the measures used to assess HRQoL do not capture all relevant issues that determine a GIST patient's HRQoL.

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.

Development and external validation of a nomogram for individualized adjuvant imatinib duration for high-risk gastrointestinal stromal tumors: A multicenter retrospective cohort study

Introduction

The main emphasis of the research about adjuvant imatinib for high‐risk gastrointestinal stromal tumors (GISTs) is prolonging the treatment duration and ignores the heterogeneous that 10‐year recurrence rates ranged from about 20%–100%. Thus, this study evaluated the effect of different durations of adjuvant imatinib on outcomes in high‐risk GISTs to explore the feasibility of individual treatment.

Methods

We analyzed 855 high‐risk GIST patients from three centers who underwent macroscopically complete resection between December 2007 and September 2020. The patients were divided into training (n =564) and two validation cohorts (n = 238 and53) based on their source. Recurrence‐free survival (RFS) was the primary point. Cox multivariate analysis was used to develop the nomogram. C‐index, time‐dependent area under the curves, and calibration plots were used to assess the performance of the nomogram.

Results

Univariate analysis showed that longer adjuvant imatinib was significantly associated with better 5‐year RFS (p < 0.0001). Further investigation identified that the same high‐risk patients with lower tumor‐associated recurrence risk benefitted little from prolonged treatment and that the recommended adjuvant imatinib duration was insufficient for those with higher recurrence risk. A nomogram for predicting 2‐, 3‐, and 5‐year RFS based on different treatment durations and four major risk factors, namely, tumor site, size, mitotic count, and rupture status, was built and validated, with a C‐index of 0.82, 0.74, and 0.70 in training and two external validation cohorts, respectively. An online dynamic nomogram was further developed for clinical applications (https://ruolinliu666.shinyapps.io/GIST/), offering predictive recurrence rates based on different treatment durations and tumor features.

Conclusions

We developed a nomogram to predict the recurrence risk for high‐risk patients according to tumor features and treatment durations of imatinib to help physicians on decision‐making for individualized treatment duration.

Medical Oncological Treatment for Patients with Gastrointestinal Stromal Tumour (GIST) - a Systematic Review

BACKGROUND

Chemotherapy is ineffective in treating patients with Gastrointestinal Stromal Tumour (GIST). However, several types of tyrosine kinase inhibitors have been investigated since the approval of imatinib in 2001. The purpose of this report was to systematically review studies on the efficacy of neoadjuvant, adjuvant, and lifelong medical oncological treatment of GIST.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed throughout the review process. The protocol was submitted to the International prospective register of systematic reviews database (ID 251724). A systematic literature search was performed, including phase II- and III studies of biological treatment, reporting on treatment effect in patients with GIST.

RESULTS

Of 308 identified publications, 42 studies were included in this review.

CONCLUSION

This review gives an overview of the existing evidence for approved lines of oncological treatments and potential alternatives for patients with GIST in the neoadjuvant-, adjuvant- and life-long setting.

Recent Advancements in the Treatment of Rectal Gastrointestinal Stromal Tumor: In Era of Imatinib

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumor of the gastrointestinal tract, with an annual incidence of 10–15 cases per million. However, rectal GIST has a low incidence, accounting for approximately 0.1% of all rectal tumors. The treatment of rectal GISTs is still controversial and the relative unified guidelines and consensus opinions are inadequate. Treatment is based primarily on the clinical experience of the physician. The widespread application of neoadjuvant imatinib therapy allows diversification of treatment, especially in the choice of surgical methods. Herein, we reviewed the most recent literature and summarized the new progress in rectal tumor treatment, with the aim of providing patients with more systematic and individualized therapeutic strategies.

Symptoms reported by gastrointestinal stromal tumour (GIST) patients on imatinib treatment: combining questionnaire and forum data

PURPOSE

Treatment with the tyrosine kinase inhibitor (TKI) imatinib in patients with gastrointestinal stromal tumours (GIST) causes symptoms that could negatively impact health-related quality of life (HRQoL). Treatment-related symptoms are usually clinician-reported and little is known about patient reports. We used survey and online patient forum data to investigate (1) prevalence of patient-reported symptoms; (2) coverage of symptoms mentioned on the forum by existing HRQoL questionnaires; and (3) priorities of prevalent symptoms in HRQoL assessment.

METHODS

In the cross-sectional population-based survey study, Dutch GIST patients completed items from the EORTC QLQ-C30 and Symptom-Based Questionnaire (SBQ). In the forum study, machine learning algorithms were used to extract TKI side-effects from English messages on an international online forum for GIST patients. Prevalence of symptoms related to imatinib treatment in both sources was calculated and exploratively compared.

RESULTS

Fatigue and muscle pain or cramps were reported most frequently. Seven out of 10 most reported symptoms (i.e. fatigue, muscle pain or cramps, facial swelling, joint pain, skin problems, diarrhoea, and oedema) overlapped between the two sources. Alopecia was frequently mentioned on the forum, but not in the survey. Four out of 10 most reported symptoms on the online forum are covered by the EORTC QLQ-C30. The EORTC-SBQ and EORTC Item Library cover 9 and 10 symptoms, respectively.

CONCLUSION

This first overview of patient-reported imatinib-related symptoms from two data sources helps to determine coverage of items in existing questionnaires, and prioritize HRQoL issues. Combining cancer-generic instruments with treatment-specific item lists will improve future HRQoL assessment in care and research in GIST patients using TKI.

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.

[Surgical and interdisciplinary treatment of gastrointestinal stromal tumors]

Gastrointestinal stromal tumors (GISTs) are the most frequent potentially malignant mesenchymal tumors of the gastrointestinal tract. The treatment of GISTs has been revolutionized since imatinib and other tyrosine kinase inhibitors were introduced for the treatment of GISTs, which inhibit the tyrosine kinases c‑KIT and platelet-derived growth factor receptor (PDGFR) alpha. Even after the introduction of this targeted treatment GISTs can only be cured by surgical resection. With interdisciplinary multimodal treatment the prognosis of metastasized GIST can now be further improved by surgical resection of the primary tumor and the metastases, potentially leading to a cure. Neoadjuvant therapy can reduce the extent of surgical resection and hereby enable organ preservation and reduce surgical morbidity. To evaluate molecular and clinical predictors and to offer an optimal therapeutic plan, patients with GISTs and certainly patients with advanced GISTs should be evaluated by interdisciplinary sarcoma boards.

Prognostic Factors After Neoadjuvant Imatinib for Newly Diagnosed Primary Gastrointestinal Stromal Tumor

INTRODUCTION

Neoadjuvant imatinib (Neo-IM) therapy may facilitate R0 resection in primary gastrointestinal stromal tumors (GISTs) that are large or in difficult anatomic locations. While response to preoperative tyrosine kinase inhibitors is associated with better outcome in metastatic GIST, little is known about prognostic factors after Neo-IM in primary GIST.

STUDY DESIGN

Patients with primary GIST with or without synchronous metastases who underwent Neo-IM were retrospectively analyzed from a prospective maintained institutional database for Response Evaluation Criteria in Solid Tumors (RECIST), tumor viability, and mitotic rate. Overall survival (OS) was estimated by Kaplan-Meier and compared by log-rank test. Cox proportionate hazard models were used for univariate and multivariate analysis.

RESULTS

One hundred and fifty patients were treated for a median of 7.1 months (range 0.2-160). By RECIST, partial response, stable disease, and progressive disease were seen in 40%, 51%, and 9%, respectively. By pathologic analysis, ≤ 50% of the tumor was viable in 72%, and the mitotic rate was ≤ 5/50HPF in 74%. On multivariate analysis, RECIST response and tumor viability were not associated with OS, while post-treatment high mitotic rate (hazard ratio (HR) for death 5.3, CI 2.3-12.4), R2 margins (HR 6.0, CI 2.3-15.5), and adjuvant imatinib (HR 0.4, CI 0.2-0.9) were (p < 0.05). Five-year OS was 81 vs. 38% for low vs. high mitotic rate; 81, 59, and 39% for R0, R1, and R2 margins; and 75 vs 61% for adjuvant vs. no adjuvant imatinib therapy (p < 0.05).

CONCLUSIONS

In primary GIST undergoing Neo-IM therapy, progression was uncommon, but substantial down-sizing occurred in the minority. High tumor mitotic rate and incomplete resection following Neo-IM were associated with poor outcome, while adjuvant imatinib was associated with prolonged survival.

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.

Starting Imatinib at 400 mg Daily in Patients with Gastrointestinal Stromal Tumors Harboring KIT Exon 9 Mutations: A Retrospective, Multicenter Study

BACKGROUND

Retrospective analyses suggest that patients with advanced KIT exon 9-mutated gastrointestinal stromal tumors (GISTs) receiving imatinib 800 mg (rather than 400 mg) daily have better outcomes. In the adjuvant setting, the question of the optimal dose of imatinib remains unsettled.

OBJECTIVE

We aimed to retrospectively assess the activity of imatinib 400 mg in both the adjuvant and the advanced settings.

PATIENTS AND METHODS

We performed a multicenter study of patients with KIT exon 9-mutated GIST starting imatinib at 400 mg daily. We examined the relapse-free survival (RFS) among high-risk patients either receiving or not receiving adjuvant imatinib. In patients with advanced disease, progression-free survival (PFS, progression under imatinib 400 mg), time to imatinib failure (TIF, progression under imatinib 400, then 800 mg upon first progression), and overall survival (OS) were analyzed.

RESULTS

In the post-operative setting (n = 37), 20 patients received adjuvant imatinib. Median RFS in high-risk patients receiving adjuvant imatinib (n = 14) was not reached (95% CI 17.5-46.6) versus 13.6 months (95% CI 4.7-13.6) for those who did not (p = 0.37), after a median follow-up of 58 months. RFS at 36 months was 63% (30.3-96.6) versus 40% (95% CI 0-82.9), p = 0.2. In advanced disease (n = 28), median PFS, TIF and OS were 12.7 months (95% CI 6.1-18.2), 21.0 months (95% CI 17.4-28.1) and 47.0 months (95% CI 33.5-69.2), respectively.

CONCLUSIONS

Despite the limitations of a retrospective analysis and the small number of patients, the benefit of adjuvant imatinib 400 mg daily in high-risk patients appeared relevant. Patients with advanced disease receiving imatinib 400 mg with subsequent dose escalation had a TIF similar to that observed with an initial dose of 800 mg. Intra-patient dose escalation in this setting might be an option.

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.

Laparoscopic resection for a large gastrointestinal stromal tumor (GIST) with diaphragm invasion following preoperative imatinib treatment: A case report

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We experienced successful treatment for large GIST with diaphragm invasion by a combination of preoperative imatinib treatment and laparoscopic resection.

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In the neoadjuvant imatinib, it is important to indicate cases and mediate the duration.

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The most important point for laparoscopic resection of large GIST is how to handle it.

Introduction

Neoadjuvant imatinib for large GISTs may prevent tumor rupture and the need for extended surgery by reducing tumor size. In this study, we present a case of large gastric GIST with diaphragm invasion, due to the patient receiving laparoscopic resection following preoperative imatinib treatment.

Presentation of case

A 72-year-old woman was hospitalized with left hypochondriac pain for a month. Examinations revealed a large heterogeneous gastric mass measuring 80 mm in size, arising from the greater curvature of the corpus. The mass invaded the left thoracic diaphragm. Treatment with imatinib at an initial dosage of 400 mg/day was initiated. After a further two months of follow-up, the lesion had sustained reduction to 50 mm in size, however, the invasion to the diaphragm remained. The patient eventually underwent laparoscopic partial gastrectomy and partial resection of the diaphragm with curative intent. Adjuvant chemotherapy was initiated at one month after the surgery, however, was discontinued due to nausea. After one-year follow-up, no recurrence was noted.

Discussion

Neoadjuvant imatinib may shrink tumor size remarkably and prevent tumor rupture during surgery, and thus lead to increased rates of complete resection. To date, several publications have directly compared the oncologic results between laparoscopic and open resection for GISTs. In the present case, the tumor was movable, and moderately fixed on diaphragm. It was favorable condition for laparoscopic surgery.

Conclusions

This is the first report of a large gastric GIST invading the diaphragm that was successfully treated by laparoscopic resection after tumor reduction by neoadjuvant imatinib.

Outcome of 1000 Patients With Gastrointestinal Stromal Tumor (GIST) Treated by Surgery in the Pre- and Post-imatinib Eras

OBJECTIVE

To characterize the results of surgery for gastrointestinal stromal tumor (GIST) in the pre and post-imatinib eras at a single institution and to identify current prognostic clinicopathologic factors.

BACKGROUND

Imatinib has radically changed the management of GIST, yet the magnitude of impact on outcome across the spectrum of GIST presentation and relevance of historical prognostic factors are not well defined.

METHODS

We retrospectively analyzed 1000 patients who underwent surgery for GIST at our institution from 1982 to 2016. Patients were stratified by presentation status as primary tumor only (PRIM), primary with synchronous metastasis (PRIM + MET), or metachronous recurrence/metastases (MET), and also imatinib era (before and after it became available). Cox proportional-hazard models and Kaplan-Meier methods were used to model and estimate overall survival (OS) and recurrence-free survival (RFS).

RESULTS

OS was longer in the imatinib era compared with the pre-imatinib era in each presentation group, including in Miettinen high-risk primary tumors. Among PRIM patients from the pre-imatinib era, tumor site, size, and mitotic rate were independently associated with OS and RFS on multivariate analysis. PRIM patients in the imatinib era who received imatinib (neoadjuvant and/or adjuvant) had higher risk tumors, but after adjusting for treatment, only size >10 cm remained independently prognostic of RFS [hazard ratio (HR) 3.85, 95% confidence interval (CI) 2.00-7.40, P < 0.0001) and OS (HR 3.37, 95% CI 1.60-7.13, P = 0.001)].

CONCLUSIONS

Patients treated in the imatinib era had prolonged OS across all presentations. In the imatinib era, among site, size, and mitotic rate, high-risk features were associated with treatment with the drug, but only size >10 cm correlated with outcome. Imatinib should still be prescribed for patients with high-risk features.

Significance of Primary Malignant Tumors on the Outcome of Patients With Resected Gastrointestinal Stromal Tumors

AIM

This study aimed to clarify the significance of primary malignant tumors for the outcome of resected gastrointestinal stromal tumors (GISTs).

PATIENTS AND METHODS

The medical history, pathological findings and prognosis of 66 patients with GISTs resected at our institute between January 2003 and December 2018 were investigated retrospectively and compared statistically.

RESULTS

Among 66 patients with GISTs, 24 (36%) had concomitant malignant tumors. In an average study period of 57 months, one patient died from GIST, seven from other malignant tumors, and one from another disease. Only coexistence of GIST and other malignant tumors was recognized as a prognostic factor. Increasing age was significantly correlated with other malignant tumor in combination with GIST. When comparing patients with GIST alone and GIST with other malignant tumors, the latter showed significantly poorer prognosis.

CONCLUSION

Coexistence of other malignant tumors was commonly observed in patients with GIST, and was associated with poorer prognosis. This association should be carefully considered and monitored in patients with GISTs.

Characteristics and prognosis of jejunoileal gastrointestinal stromal tumours (GISTs) in the era of imatinib: a comparative study with gastric GISTs

BACKGROUND

Gastrointestinal stromal tumours (GISTs) located in the jejunum or ileum (JI-GIST) are considered worse prognosis compared to those of gastric (G-GIST) location. It has been suggested that this dogma should be revised. The aim of this study was to describe the characteristics of jejunoileal GISTs and its prognosis and to compare them with G-GISTs in the era of imatinib.

METHODS

We retrospectively reviewed the clinical histories of all the patients diagnosed with GISTs between January 2000 and November 2016: Clinical and pathological data, as recurrence, metastatic state, disease-free survival (DFS) as well as overall survival (OS) rates of patients were reviewed.

RESULTS

JI-GIST patients comprise 29 cases (37.7%). Compared to G-GIST, JI-GIST patients had undergone emergency surgery more frequently (37.9% vs. 10.4%, p = 0.007). According to the NIH-Fletcher classification, the low or very-low risk group represents 17.2% of JI-GISTs as opposed to 37.6% of G-GISTs (p < 0.005). When the AFIP-Miettinen system was used the low or very-low group represented 17.2% of JI-GISTs vs. 58.4% in the G-GISTs group (p < 0.001). Both local recurrence (24.1% vs. 12.5%, p < 0.05) and metastatic rate (34.5% vs. 22.9%, p < 0.05) were higher in the JI-GIST group than in G-GIST. 5- and 10-year DFS and 10-year OS rate were lower for JI-GIST (54.5% and 39.6% vs. 77.2% and 60.8%, and 57.9% vs. 65%, respectively, p < 0.05).

CONCLUSIONS

The observed differences between both groups in DFS and OS rates at long term could be attributed to the effect of imatinib.

Survival Outcomes Associated With 3 Years vs 1 Year of Adjuvant Imatinib for Patients With High-Risk Gastrointestinal Stromal Tumors: An Analysis of a Randomized Clinical Trial After 10-Year Follow-up

Importance

Adjuvant imatinib is associated with improved recurrence-free survival (RFS) when administered after surgery to patients with operable gastrointestinal stromal tumor (GIST), but its influence on overall survival (OS) has remained uncertain.

Objective

To evaluate the effect of adjuvant imatinib on OS of patients who have a high estimated risk for GIST recurrence after macroscopically complete surgery.

Design, Setting, and Participants

In this open-label, randomized (1:1), multicenter phase 3 clinical trial conducted in Finland, Germany, Norway, and Sweden, 400 patients who had undergone macroscopically complete surgery for GIST with a high estimated risk for recurrence according to the modified National Institutes of Health Consensus Criteria were enrolled between February 2004 and September 2008. Data for this follow-up analysis were analyzed from September to November, 2019.

Interventions

Imatinib 400 mg/d administered orally for either 12 months or 36 months after surgery.

Main Outcomes And Measures

The primary end point was RFS; the secondary objectives included OS and treatment safety.

Results

The intention-to-treat cohort consisted of 397 patients (12-month group, 199; 36-month group, 198; 201 men and 196 women; median [IQR] age, 62 (51-69) years and 60 (51-67) years, during a median follow-up time of 119 months after the date of randomization, 194 RFS events and 96 OS events were recorded in the intention-to-treat population. Five-year and 10-year RFS was 71.4% and 52.5%, respectively, in the 36-month group and 53.0% and 41.8% in the 12-month group (hazard ratio [HR], 0.66; 95% CI, 0.49-0.87; P = .003). In the 36-month group, 5-year OS and 10-year OS rates were 92.0% and 79.0%, respectively, and in the 12-month group 85.5% and 65.3% (HR, 0.55; 95% CI, 0.37-0.83; P = .004). The results were similar in the efficacy population, from which 15 patients who did not have GIST in central pathology review and 24 patients who had intra-abdominal metastases removed at surgery were excluded (36-month group, 10-year OS 81.6%; 12-month group, 66.8%; HR, 0.50; 95% CI, 0.32-0.80; P = .003). No new safety signals were detected.

Conclusions and Relevance

Three years of adjuvant imatinib is superior in efficacy compared with 1 year of imatinib. Approximately 50% of deaths may be avoided during the first 10 years of follow-up after surgery with longer adjuvant imatinib treatment.

Trial Registration

ClinicalTrials.gov Identifier: NCT00116935.

Final analysis of the randomized trial on imatinib as an adjuvant in localized gastrointestinal stromal tumors (GIST) from the EORTC Soft Tissue and Bone Sarcoma Group (STBSG), the Australasian Gastro-Intestinal Trials Group (AGITG), UNICANCER, French Sarcoma Group (FSG), Italian Sarcoma Group (ISG), and Spanish Group for Research on Sarcomas (GEIS)☆

BACKGROUND

In 2004, we started an intergroup randomized trial of adjuvant imatinib versus no further therapy after R0-R1 surgery in localized, high/intermediate-risk gastrointestinal stromal tumors (GIST) patients. Interim analysis results were published in 2015 upon recommendation from an independent data review committee. We report the final outcome of the study.

PATIENTS AND METHODS

This was a randomized, open-label, multicenter phase III trial carried out at 112 hospitals in 12 countries. Patients were randomized to 2 years of imatinib, 400 mg daily, or no further therapy after surgery. The primary endpoint was imatinib failure-free survival (IFFS), while relapse-free survival (RFS), relapse-free interval (RFI), overall survival (OS) and toxicity were secondary endpoints. Adjusting for the interim analyses, results on IFFS were assessed on a 4.3% significance level; for the other endpoints, 5% was used.

RESULTS

Nine hundred and eight patients were randomized between January 2005 and October 2008: 454 to imatinib and 454 to observation; 835 patients were eligible. With a median follow-up of 9.1 years, 5 (10)-year IFFS was 87% (75%) in the imatinib arm versus 83% (74%) in the control arm [hazard ratio (HR) = 0.87, 95.7% confidence interval (CI) (0.65; 1.15), P = 0.31]; RFS was 70% versus 63% at 5 years and 63% versus 61% at 10 years, [HR = 0.71, 95% CI (0.57; 0.89), P = 0.002]; OS was 93% versus 92% at 5 years and 80% versus 78% at 10 years [HR = 0.88, 95% CI (0.65; 1.21), P = 0.43]. Among 526 patients with high-risk GIST by local pathology, 10-year IFFS and RFS were 69% versus 61%, and 48% versus 43%, respectively.

CONCLUSIONS

With 9.1 years of follow-up, a trend toward better long-term IFFS in imatinib-treated patients was observed in the high-risk subgroup. Although the difference was not statistically significant and the surrogacy value of such an endpoint is not validated, this may be seen as supporting the results reported by the Scandinavian/German trial, showing a sustained small but significant long-term OS benefit in high-risk GIST patients treated with 3 years of adjuvant imatinib.

Deciding on the duration of adjuvant therapy in gastrointestinal stromal tumor

Introduction: The benefit of the tyrosine kinase inhibitor (TKI) imatinib mesylate in metastatic Gastrointestinal Stromal Tumors (GIST) leads to improved progression-free survival (PFS) and overall survival (OS). Clinical trials of adjuvant imatinib have provided data on the utility in management of primary GIST. There still remains uncertainty regarding the optimal duration of therapy.Areas covered: Here, we review the literature on the pivotal clinical trials evaluating adjuvant imatinib: ACOSOG Z9000/Z9001, EORTC 62024, Scandinavian Sarcoma Group XVIII, and PERSIST-5. The data from these studies that were analyzed included the patient population, length of therapy, and outcomes.Expert opinion: Clinical trial data demonstrate that adjuvant imatinib delays recurrence and appears to improve survival when taken for 3 years in high-risk patients; treatment for 5 years has been found to be safe, although difficult for patients to maintain adherence. These studies all incorporated slightly different patient populations based upon eligibility criteria for risk of recurrence, but support the use in patients with intermediate to high risk of disease recurrence. Data from these studies does not support treating those with low risk of recurrence or imatinib-insensitive mutations.

The Landmark Series: Systemic Therapy for Resectable Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. Complete resection is the only potentially curative treatment, although recurrence is common, occurring in approximately 40–50% of patients. The introduction of effective molecularly targeted therapies for GISTs has dramatically changed the clinical management paradigms for, and prognosis of, patients with intermediate- and high-risk GISTs, as well as those with locally advanced and metastatic disease. In this article, we review landmark studies that evaluated the use and efficacy of the tyrosine kinase inhibitors imatinib and sunitinib in the adjuvant and neoadjuvant settings for resectable primary and limited resectable metastatic GISTs.

Adjuvant systemic therapy for small bowel gastrointestinal stromal tumor (GIST): Is there a survival benefit after R0 resection?

BACKGROUND

The utility of adjuvant systemic therapy in small bowel gastrointestinal stromal tumor remains unclear.

METHODS

We queried the National Cancer Data Base for individuals having enterectomy to negative margins for small bowel gastrointestinal stromal tumor between 2010 and 2015. Subjects were categorized by tumor size (2.1-5 cm, 5.1-10 cm, >10 cm) and histologic grade (≤5 mitoses/50 high-power field and >5 mitoses/50 high-power field). Cox proportional hazard analysis was performed to evaluate the association between adjuvant therapy and overall survival.

RESULTS

One thousand five hundred fifty-nine patients met the inclusion criteria. On univariate comparison to resection alone, adjuvant therapy was associated with improved overall survival for individuals with high-grade tumors of intermediate and large size (85% vs 48%, P = .010; 75% vs 47%, P = .003) but not for those with high-grade tumors of small size or low-grade tumors of any size. On multivariable analysis adjusted for age, comorbid disease state, and tumor size, adjuvant therapy was independently associated with reduced risk of mortality for high-grade (hazard ratio 0.37, 95% confidence interval: 0.21-0.64) but not low-grade tumors.

CONCLUSION

Adjuvant therapy after R0 resection for small bowel gastrointestinal stromal tumor should be administered after careful consideration of the size and grade of a patient's tumor.

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.

The MNK1/2-eIF4E Axis as a Potential Therapeutic Target in Melanoma

: Melanoma is a type of skin cancer that originates in the pigment-producing cells of the body known as melanocytes. Most genetic aberrations in melanoma result in hyperactivation of the mitogen activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) pathways. We and others have shown that a specific protein synthesis pathway known as the MNK1/2-eIF4E axis is often dysregulated in cancer. The MNK1/2-eIF4E axis is a point of convergence for these signaling pathways that are commonly constitutively activated in melanoma. In this review we consider the functional implications of aberrant mRNA translation in melanoma and other malignancies. Moreover, we discuss the consequences of inhibiting the MNK1/2-eIF4E axis on the tumor and tumor-associated cells, and we provide important avenues for the utilization of this treatment modality in combination with other targeted and immune-based therapies. The past decade has seen the increased development of selective inhibitors to block the action of the MNK1/2-eIF4E pathway, which are predicted to be an effective therapy regardless of the melanoma subtype (e.g., cutaneous, acral, and mucosal).

Activity and safety of the multi-target tyrosine kinase inhibitor cabozantinib in patients with metastatic gastrointestinal stromal tumour after treatment with imatinib and sunitinib: European Organisation for Research and Treatment of Cancer phase II trial 1317 'CaboGIST'

BACKGROUND

Gastrointestinal stromal tumour (GIST) is commonly treated with tyrosine kinase inhibitors (TKIs), but most patients ultimately develop secondary resistance. Cabozantinib, a multi-targeted TKI inhibitor, has activity in patient-derived GIST mouse xenograft models and can overcome compensatory MET signalling occurring on TKI treatment. European Organisation for Treatment of Cancer (EORTC) 1317 'CaboGIST' assessed the safety and activity of cabozantinib in patients with GIST who had progressed on imatinib and sunitinib.

METHODS

In this multi-center, open label, single arm phase II study, eligible GIST patients received oral cabozantinib (60 mg) once daily. Primary end-point was the progression-free survival rate at 12 weeks assessed by the local investigator per Response Evaluation Criteria in Solid Tumours 1·1. If at least 21 of the first 41 eligible and evaluable patients were progression-free at week 12, the activity of cabozantinib was sufficient to warrant further exploration according to the A'Hern one-stage study design.

FINDINGS

A total of 50 eligible patients started treatment between 02/2017 and 08/2018, including four (8%) still continuing cabozantinib at clinical cut-off (09/2019). The number of 3-weekly treatment cycles ranged from 1 to 30. Among the first 41 eligible and evaluable patients, 24 were progression-free at week 12 (58·5%, 95% confidence interval [CI] 42·0-74·0%). Among all 50 patients, 30 were progression-free at week 12 (60%, 95% CI 45-74%). Seven patients achieved a partial response (14%, 95% CI 6-27%), and 34 had stable disease (68%, 95% CI 53-80%) as best response. Progression was seen in eight patients (16%, 95% CI 7-29%), and one was not evaluable. Disease control was achieved in 41 patients (82%, 95% CI 69-91%). Median progression-free survival was 5·5 months (95% CI 3·6-6·9). The most common adverse events were diarrhoea (76%), palmar-plantar erythrodysesthesia syndrome (60%), fatigue (50%), hypertension (42%), weight loss (40%) and oral mucositis (30%), with 32 (64%) patients requiring dose reductions, 27 (54%) having treatment interruptions and no cabozantinib-related deaths observed.

INTERPRETATION

EORTC 1317 met its primary end-point, with 24/41 patients being progression-free at week 12 of treatment. The objective response was 14% with an encouraging disease control rate of 82%. Results of this trial confirm preclinical findings and warrant further exploration of cabozantinib in GIST.

CLINICAL TRIAL NUMBERS

EORTC 1317, NCT02216578, EudraCT 2014-000501-13.