Surgery for metastatic gastrointestinal stromal tumor: to whom and how to?

Ibero-American Consensus for the Management of Peritoneal Sarcomatosis: Updated Review and Clinical Recommendations

Peritoneal sarcomatosis is a rare malignant disease with a poor prognosis, secondary to peritoneal dissemination of abdominopelvic soft tissue sarcomas. Its rarity, together with the characteristic histological heterogeneity and the historically poor response to systemic treatments, has prevented the establishment of widely accepted treatment criteria with curative intent. In this sense, radical cytoreductive surgery (CRS) with peritonectomy procedures and hyperthermic intraperitoneal chemotherapy (HIPEC), widely used in peritoneal carcinomatosis with excellent results, have not had the same evolutionary development in patients with peritoneal sarcomatosis. A multidisciplinary working group of experts in sarcomas and peritoneal oncological surgery established a series of recommendations based on current scientific evidence for the management of peritoneal sarcomatosis, taking into account the different histological subgroups of abdominopelvic sarcomas that can cause it depending on their origin: retroperitoneal sarcomas, uterine sarcomas, and visceral/peritoneal sarcomas of GIST (gastrointestinal stromal tumor) and non-GIST origin. This article shows the results of sarcoma experts' voting on the recommendations presented during the I Ibero-American Consensus on the Management of Peritoneal Sarcomatosis, which took place during the recent celebration of the III Hispanic-Portuguese Meeting for Updates on the Treatment of 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.

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.

From KIT-mutated into wild-type: dedifferentiation of gastrointestinal stromal tumor in adolescent patient-a case report

Background

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract, usually found in elderly adults. It is infrequent among pediatric patients and usually differs from adult-type disease in terms of histopathology and molecular features.

Case Description

We describe the management of the disease in a 10-year-old female patient diagnosed with a GIST of the stomach. In total, she has undergone successively total tumor resection, unsuccessful imatinib treatment and subtotal gastric resection at relapse. The first genetic test from primary tumor confirmed KIT mutations in exons 13 and 17, while the repeated genetic screening using tumor sample from subtotal gastric resection revealed no KIT or platelet-derived growth factor receptor α (PDGFRA) genes mutations. Such dedifferentiation from adult type (thus KIT-mutated) into wild-type (without KIT or PDGFRA mutation) has not been reported so far to the best of our knowledge. Currently, the patient is observed, and no further pharmacological nor surgical treatment has been administered.

Conclusions

The case underlines the importance of genetic profiling combined with non-standard diagnostics (both histopathological and radiological) due to the treatment efficacy prediction. We moreover emphasize the necessity to create worldwide standards on the diagnostics and treatment of GIST in pediatric patients that would include options of targeted therapies.

Cytoreductive surgery offers prognostic benefits in metastatic gastrointestinal stromal tumors with generalized progression following imatinib therapy: a single institute retrospective study

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Distant metastasis has been detected in approximately 50% of GIST patients at the first diagnosis. The surgical strategy for metastatic GIST with generalized progression (GP) after imatinib therapy remains unclear.

METHODS

We recruited 15 patients with imatinib-resistant metastatic GIST. They received cytoreductive surgery (CRS) for tumor rupture, intestinal obstruction and gastrointestinal bleeding. We collected clinical, pathological and prognostic data for analyses.

RESULTS

OS and PFS after R0/1 CRS were 56.88 ± 3.47 and 26.7 ± 4.12 months, respectively, when compared with 26 ± 5.35 and 5 ± 2.78 months after R2 CRS (P = 0.002 and P < 0.001, respectively). The OS of patients from the initiation of imatinib in the R0/1 group was 133.90 ± 15.40 months when compared with 59.80 ± 10.98 months in the R2 CRS group. There were two significant grade III complications after 15 operations (13.3%). No patient underwent reoperation. In addition, no perioperative death occurred.

CONCLUSIONS

R0/1 CRS is highly probable to provide prognostic benefits for patients with metastatic GIST who experience GP following imatinib treatment. An aggressive surgical strategy for achieving R0/1 CRS can be deemed safe. If applicable, R0/1 CRS should be carefully considered in imatinib-treated patients with GP metastatic GIST.

Might Patients with Metastatic Gastrointestinal Stromal Tumors Benefit from Operative Management? A Population-Based Retrospective Study

Background

With respect to effect of surgery on the therapy of patients with metastatic gastrointestinal stromal tumors (mGISTs), still no consensus has been reached. This research designed to investigate the effect of surgical treatment on prognosis in patients with mGISTs.

Methods

The population-based study consisted of 6282 GIST patients diagnosed between 2001 and 2016, from the Surveillance, Epidemiology, and End Results (SEER) database registry. The Kaplan-Meier method and Cox model were employed for the exploration of the effect of surgery on overall survival (OS) and GIST-specific survival (GSS).

Results

In total, 6282 patients were diagnosed with GISTs, including 1238 (19.7%) mGIST patients and 5044 (80.3%) non-mGIST patients. Compared with the patients with non-mGISTs, metastatic patients assumed relatively lower proportion of surgical management (756 [61.1%] vs. 4666 [92.5%], P < 0.001). Based on unadjusted analysis, mGIST patients with operative management presented higher five years OS together with GSS in comparison with those without operative management (OS: 58.3% vs. 33.1%, P < 0.001; GSS: 61.6% vs. 36.7%, P < 0.001). Multivariable analysis found that no surgery was correlated to more than 2-fold increased death risk (OS, adjusted HR = 2.27, 95% CI: 1.90-2.71; GSS, adjusted HR = 2.42, 95% CI: 2.00-2.93).

Conclusion

Metastatic GIST patients could potentially benefit from operative management with improved GSS and OS.

Current evidence on laparoscopic vs. open resection for gastric stromal tumours

Although the use of laparoscopic surgery is increasing, controversy still surrounds its application for malignant conditions. Gastrointestinal stromal tumours (GISTs) are less demanding in terms of lymphadenectomy, meaning that laparoscopic resection might have a more defined benefit when compared with open resection. To the best of our knowledge, no randomized study exists that compares the laparoscopic and open resection of GISTs. The current study aimed to examine the relevant literature by means of a systematic review. A systematic literature search was performed individually by two authors, in which three independent databases were searched using specific search-terms. Titles, abstracts and full texts were screened, as well as references to relevant articles, in order to comprise a comprehensive list of studies. Data were extracted using a detailed pre-agreed spreadsheet. Studies were evaluated according to the modified MINORS criteria. A total of 10 studies were included in the present review, yielding a total of 14 entries. The majority of studies reported significantly improved perioperative outcomes for the laparoscopic approach, including improved duration of operation, blood loss and length of hospital stay. Only four studies reported long-term outcomes and findings that were controversial, with some studies detecting no statistically significant differences, one reporting improved and one reporting worse disease-free and overall survival for the laparoscopic group. Three studies were deemed to be good quality, two of which had not reported significantly different long-term outcomes, while the third had reported significantly improved outcomes in the open resection group. While there is a clear benefit for performing laparoscopic surgery in patients with GIST with regards to perioperative outcomes, when it comes to long-term oncological outcomes, uncertainty over its application remains. The lack of randomized trials, as well as the poor reporting of retrospective studies, limits the amount of evidence that is currently available. Laparoscopic surgery for GIST is certainly safe, feasible and likely cost-effective; however, further studies are required to inform on whether this technique is superior to open resection.

Surgical Management of Metastatic Gastrointestinal Stromal Tumors

OPINION STATEMENT

Treatment with the tyrosine kinase inhibitor (TKI), imatinib is the standard first-line treatment for metastatic gastrointestinal stromal tumors (GISTs). Unfortunately, acquired c-kit mutations cause secondary resistance to imatinib in a median of 18-24 months. Sunitinib and regorafenib are multi-kinase inhibitors that can be used as second-line or third-line therapy in imatinib-resistant or -intolerant GISTs, respectively. Ripretinib (a switch-control tyrosine kinase inhibitor) has recently been approved for fourth-line treatment in metastatic GIST. The TKI avapritinib has been approved for metastatic GIST harboring the imatinib-resistant PDGFRA exon 18 mutation. Although TKI therapies have revolutionized the treatment of metastatic GISTs, they cannot cure metastatic GISTs. Therefore, cytoreductive surgery is of considerable interest and has been accordingly investigated. Retrospective non-randomized studies demonstrated the feasibility and safety of continuous TKI therapy and surgical resection. Most studies demonstrate response to TKI therapy, completeness of resection, extent of disease, and surgical complexity as predictors of outcomes. Most TKIs can be stopped shortly before surgery and restarted shortly after. There is no known survival benefit from debulking operations or R2 resections and this should not be considered. However, debulking/palliative surgery may be necessary for patients with complications of hemorrhage, pain, or intestinal obstruction. SDH-deficient GISTs have an indolent natural history despite metastatic disease and may be another uncommon subgroup that would benefit from surgical debulking (R2 resection). At the time of operation, care should be taken to avoid tumor rupture. After surgical resection, patients should resume tyrosine kinase inhibitor (TKI) therapy as soon as possible and be monitored for disease progression. In all patients with metastatic GIST, the decision to pursue metastasectomy for GIST should be made in a multidisciplinary setting and be individualized according to patient age, comorbidities, functional status, symptoms, mutation status, extent of disease, completeness of resection, TKI response, and goals of the patient.

Gastrointestinal Stromal Tumors (GISTs): Novel Therapeutic Strategies with Immunotherapy and Small Molecules

Gastrointestinal stromal tumors (GISTs) are the most common types of malignant mesenchymal tumors in the gastrointestinal tract, with an estimated incidence of 1.5/100.000 per year and 1–2% of gastrointestinal neoplasms. About 75–80% of patients have mutations in the KIT gene in exons 9, 11, 13, 14, 17, and 5–10% of patients have mutations in the platelet-derived growth factor receptor a (PDGFRA) gene in exons 12, 14, 18. Moreover, 10–15% of patients have no mutations and are classified as wild type GIST. The treatment for metastatic or unresectable GISTs includes imatinib, sunitinib, and regorafenib. So far, GIST therapies have raised great expectations and offered patients a better quality of life, but increased pharmacological resistance to tyrosine kinase inhibitors is often observed. New treatment options have emerged, with ripretinib, avapritinib, and cabozantinib getting approvals for these tumors. Nowadays, immune checkpoint inhibitors form a new landscape in cancer therapeutics and have already shown remarkable responses in various tumors. Studies in melanoma, non-small-cell lung cancer, and renal cell carcinoma are very encouraging as these inhibitors have increased survival rates. The purpose of this review is to present alternative approaches for the treatment of the GIST patients, such as combinations of immunotherapy and novel inhibitors with traditional therapies (tyrosine kinase inhibitors).

Primary Tumor Resection Improves Survival in Patients With Metastatic Gastrointestinal Stromal Tumors: A Preliminary Population-Based Analysis

Background: Surgery has been the primary treatment in patients with localized gastrointestinal stromal tumors (GISTs) for many decades, whereas it remains controversial regarding the efficacy of primary tumor resection for metastatic GISTs treated with chemotherapy, and likewise it is unclear who would benefit from the surgical resection.

Methods: GISTs patients with distant metastases were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2016. Cox proportional hazards regression models were used to identify prognostic factors of overall survival (OS) and cancer-specific survival (CSS). Kaplan-Meier analyses and log-rank tests were conducted to assess the effectiveness of surgery on survival.

Results: In total, of 455 patients with metastatic GISTs, 235 patients (51.6%) underwent primary tumor resection and 220 patients (48.4%) did not. Median survival of patients in resection group was 72 (95% CI: 62.90–81.10) months vs. 40 (95% CI: 29.53–50.47) months for those in non-resection group (p < 0.001). Similarly, surgery in conjunction with chemotherapy led to a favorable impact on survival than chemotherapy alone (OS: 72 vs. 40 months, p < 0.001; CSS: 74 vs. 44 months, p < 0.001). Multivariable analysis showed that both OS (HR: 0.581, 95% CI: 0.386–0.874, p = 0.009) and CSS (HR: 0.663, 95% CI: 0.439–0.912, p = 0.042] were dramatically improved in patients with surgical removal of primary site, as well as primary tumor size between 5 and 10 cm, while increasing age was predictive of poorer survival. Stratified analysis revealed that patients with tumor locations in the stomach demonstrated a prolonged survival after surgery, with no significant differential surgical effect between the stomach and small intestine.

Conclusions: Our study preliminarily suggests that carefully selected patients with metastatic GISTs might prolong survival after treatment of surgery, especially those with a primary tumor between 5 and 10 cm and a tumor located in the stomach.

Long-term adjuvant imatinib treatment for a patient who underwent complete resection of a localized recurrent gastrointestinal stromal tumor after preoperative imatinib treatment: A case report

RATIONALE

The efficiency and tolerance of long-term adjuvant imatinib treatment for patient who underwent complete resection of a localized recurrent gastrointestinal stromal tumor (GIST) was unknown.

PATIENT CONCERNS

A 45-year-old man underwent complete resection of an intestinal GIST in August 2001. Four years later, a giant (11 × 8 × 6 cm) recurrent GIST located in the retroperitoneum was detected.

DIAGNOSIS

The recurrent tumor was positive for CD117 by immunohistochemistry.

INTERVENTIONS

The recurrent tumor was completely resected after 4 months of effective imatinib treatment (400 mg/day), and the patient continued imatinib treatment postoperatively. In June 2011, imatinib treatment was stopped for 3 weeks because of hepatitis B infection, and resumed with a reduced dose level of 300 mg/day when liver function recovered. In March 2017, imatinib treatment was interrupted again for 12 days because the patient underwent cholecystectomy.

OUTCOMES

In December 2017, a computed tomography scan showed no signs of tumor recurrence. To date, the patient has been under adjuvant imatinib treatment for >12 years without severe side effects. The plasma concentration of imatinib (detected in February 2018) was trough concentration (Cmin) 1015.7 ng/mL and peak concentration (Cmax) 1550.5 ng/mL.

LESSONS

This case report highlights the active role of long-term (>12 years) imatinib treatment after complete resection of localized recurrent GIST.