Primary surgery as a frontline treatment for synchronous metastatic gastrointestinal stromal tumors: an analysis of the Kinki GIST registry

A successful complete resection for multidrug-resistant giant gastrointestinal stromal tumor invading the transverse colon with multiple liver metastases in a young female: a case report

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are rare in young people and are often detected after becoming symptomatic or at an advanced stage. Herein, we report a case of complete reduction surgery for a substantially large malignant gastric GIST with multiple liver metastases in a young woman who successfully resulted in R0 surgery.

CASE PRESENTATION

An 18-year-old woman presented to our hospital with anorexia and vomiting, and was diagnosed with a 17 cm gastric GIST with transverse colon invasion and multiple liver metastases. Due to being considered unresectable, tyrosine and multi-kinase inhibitor therapy were administered up to the fourth line yielding no response. After careful discussion at a multidisciplinary team conference, pancreatoduodenectomy or distal gastrectomy, transverse colectomy, and resection of the liver metastases were planned. Consequently, distal gastrectomy, transverse colectomy, resection of the liver metastases, and incidental peritoneal metastases were performed. Although the primary goal of the surgery was to reduce the volume of the tumor as much as possible, the results revealed that the complete removal of all detectable tumors was achieved. No recurrence was observed after surgery for 27 months with long-term adjuvant imatinib therapy.

CONCLUSIONS

Even for highly advanced GISTs, aggressive surgery followed by adjuvant drug therapy may prolong survival in young patients.

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.

Role of Surgery in the Management of Liver Metastases From Gastrointestinal Stromal Tumors

Background

The clinical benefit of hepatectomy in patients with liver metastases from gastrointestinal stromal tumors (GIST) has not been well defined in this era of tyrosine kinase inhibitor (TKI). Our study aims to demonstrate the survival advantage of adding hepatectomy in patients with GIST liver metastases.

Methods

Information on patients with metastatic GIST treated or consulted between January 2006 and December 2018 was retrieved. Patients without extrahepatic metastases were included and classified into the surgical (S group) and non-surgical (NS group). Clinicopathological features were compared and their association with survival was assessed.

Results

A total of 119 patients were included in this retrospective analysis, 62 in the S group and 59 in the NS group. Comparison of clinicopathological features showed that a markedly higher proportion of patients in the S group had ≤3 hepatic lesions (79.0% vs. 29.8%, p<0.001). After a median follow-up duration of 56 months, patients in the S group had significantly better progression-free survival (PFS) and marginally improved overall survival (OS) than those in the NS group (3y PFS:86.2% vs. 64.6%, p=0.002; 5y OS: 91.5% vs. 78.3%, p=0.083). After propensity score matching, multivariate analysis identified hepatectomy as the only significant prognostic factor for PFS while age, hepatectomy and max tumor diameter were significant predictor for OS.

Conclusions

Addition of hepatectomy provided longer disease control in patients with metastatic GIST confined to the liver. Upfront hepatectomy followed by imatinib therapy is worthwhile trying in patients with single and easily removable lesions.

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.

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.

Liver surgery prolongs the survival of patients with gastrointestinal stromal tumor liver metastasis: a retrospective study from a single center

Objectives

Gastrointestinal stromal tumor (GIST) liver metastasis (GLM) is a special subset of advanced GIST, because its lesions are easier to define and assess. We aim to determine the role of liver metastasectomy for patients with GLM in the era of tyrosine kinase inhibitor (TKI) therapy.

Methods

We reviewed patients with metastatic GIST who received surgery or other treatments in Sun Yat-sen University Cancer Center between January 1991 and December 2017. Patients with metastases confined to the liver and with no previous metastasis to other locations were included into the study and were classified into surgical and non-surgical groups. All patients received 400 mg/d imatinib after the operation. We compared progression-free survival (PFS) and overall survival (OS) between the two groups.

Results

A total of 102 patients were included into the study. Of them, 21 (20.1%) underwent surgery for liver metastases and 81 (79.9%) received TKI therapy alone. During the operation, six patients received radiofrequency ablation for suspicious or unresectable lesions. Three-year PFS rate was 77.5% in the surgical group and 65.5% in the non-surgical group (P=0.027); 5-year OS rate was 85.7% and 59.6%, respectively (P=0.008). About 22.1% of patients had metastases of less than three in the surgical group, while the rate was 42.9% in the non-surgical group (P=0.011). Patients with metastases of less than three had longer PFS than those with three or more, with a 3-year PFS rate of 72.8% and 65.8%, respectively (P=0.019). But their difference in 5-year OS rate was not significant (91.7% vs 55.3%, P=0.08).

Conclusion

Followed by continuous TKI therapy, R0 surgery significantly prolongs the survival of patients with GLM, regardless of the extent of disease or the phase of metastasis.

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

Although imatinib is a standard treatment for metastatic or recurrent gastrointestinal stromal tumors (GISTs), acquired c-kit mutations reportedly cause secondary resistance to imatinib. Sunitinib is a tyrosine kinase inhibitor (TKI) that can be used as second-line therapy in imatinib-resistant or -intolerant GISTs. For sunitinib-resistant or -intolerant GISTs, regorafenib is a standard third-line treatment. Although TKI therapies have revolutionized the treatment of recurrent or metastatic GISTs, they cannot cure GISTs. Therefore, in the era of TKIs, role of cytoreductive surgery for recurrent or metastatic GISTs has been discussed. Retrospective studies of treatment strategies with front-line surgery prior to imatinib have shown that initial cytoreduction confers no benefit in cases of advanced or recurrent GIST, and administering imatinib is the principle treatment. Most retrospective studies report cytoreductive surgery to be feasible in patients with metastatic GIST whose disease is stable or responsive to imatinib. Cytoreductive surgery may be indicated in limited disease progression refractory to imatinib when complete resection is possible, but case selection is critical. Cytoreductive surgery for metastatic GIST treated with sunitinib seems less feasible because of high rates of incomplete resections and complications. The role of cytoreductive surgery for metastatic GISTs would be difficult to establish in a prospective study; individualized treatments need to be carefully designed based on c-kit and platelet-derived growth factor receptor alpha (PDGFRA) mutations and other factors.

Appropriate Follow-Up Strategies for Gastrointestinal Stromal Tumor Patients Based on the Analysis of Recurrent Interval and Patterns

BACKGROUND/AIMS

Previous studies have proposed risk classifications for patients with gastrointestinal stromal tumor (GIST) after resection and have contributed to the prediction of its prognosis. However, optimal postoperative surveillance has not yet been established.

METHODS

We retrospectively analyzed data from 115 GIST patients who experienced recurrence after complete resection. The relationships between clinicopathological characteristics and the first recurrence sites, or time to recurrence (TTR), were investigated. We also compared the characteristics between 2 subgroups based on a TTR of ≤5 or >5 years.

RESULTS

The first recurrence occurred in the abdomen in 114 of 115 patients (99.1%); one case of esophageal GIST recurred in the lung. Gastric and small intestinal GISTs recurred most frequently in the liver or peritoneum, while the most common recurrences of colorectal GISTs were found to be local. Fourteen patients (12.2%) experienced recurrence after >5 years. Smaller tumors and those categorized as lower risk were significantly more frequent in the TTR >5 years group than in the TTR ≤5 years group. In the TTR >5 years group, local recurrence was the most frequent type of recurrence (42.9%).

CONCLUSION

Based on abdominal examination, postoperative surveillance after complete resection for primary GISTs may be recommended for >5 years.

Surgical resection of recurrent gastrointestinal stromal tumor after interruption of long-term nilotinib therapy

Background

Nilotinib inhibits the tyrosine kinase activities of ABL1/BCR-ABL1, KIT, and platelet-derived growth factor receptors (PDGFRs). The results of a phase III clinical trial indicated that nilotinib could not be recommended for broad use as first-line therapy for gastrointestinal stromal tumor (GIST). However, some clinical studies have reported the effectiveness of nilotinib. We report here the cases of two patients who underwent surgical resections of nilotinib-resistant lesions after long-term nilotinib administration.

Case presentation

Two Japanese female patients, aged 66 and 70 years, experienced peritoneal recurrence of intestinal GIST several years after surgery. Both were registered in the ENESTg1 trial and received nilotinib therapy. Although they continued nilotinib administration with a partial response according to the protocol, nilotinib-resistant lesions, which were diagnosed as focally progressive disease, developed and complete surgical resection was performed. Pathological examination revealed that the tumors were composed of viable KIT-positive spindle cells, and the recurrent tumors were diagnosed as nilotinib-resistant GIST. In gene mutation analysis, a secondary KIT gene mutation was detected in one case. Both patients have survived more than 5 years after the first surgery.

Conclusions

Of patients who were registered in this trial, we have encountered two patients with long-term effects after nilotinib administration. Moreover, secondary mutations in the KIT gene, similar to those involved in resistance to imatinib, might be involved in resistance to nilotinib.