Surgical management of metastatic gastrointestinal stromal tumour

Local treatment in metastatic GIST patients: A multicentre analysis from the Dutch GIST Registry

BACKGROUND

The added value of local treatment in selected metastatic GIST patients is unclear. This study aims to provide insight into the usefulness of local treatment in metastatic GIST by use of a survey study and retrospective analyses in a clinical database.

METHODS

A survey study was conducted among clinical specialists to select most relevant characteristics of metastatic GIST patients considered for local treatment, defined as elective surgery or ablation. Patients were selected from the Dutch GIST Registry. A multivariate Cox-regression model for overall survival since time of diagnosis of metastatic disease was estimated with local treatment as a time-dependent variable. An additional model was estimated to assess prognostic factors since local treatment.

RESULTS

The survey's response rate was 14/16. Performance status, response to TKIs, location of active disease, number of lesions, mutation status, and time between primary diagnosis and metastases, were regarded the 6 most important characteristics. Of 457 included patients, 123 underwent local treatment, which was associated with better survival after diagnosis of metastases (HR = 0.558, 95%CI = 0.336-0.928). Progressive disease during systemic treatment (HR = 3.885, 95%CI = 1.195-12.627) and disease confined to the liver (HR = 0.269, 95%CI = 0.082-0.880) were associated with worse and better survival after local treatment, respectively.

CONCLUSION

Local treatment is associated with better survival in selected patients with metastatic GIST. Locally treated patients with response to TKIs and disease confined to the liver have good clinical outcome. These results might be considered for tailoring treatment, but should be interpreted with care because only specific patients are provided with local treatment in this retrospective study.

Evolution of Patterns of Care and Outcomes in the Real-Life Setting for Patients with Metastatic GIST Treated in Three French Expert Centers over Three Decades

Gastrointestinal stromal tumors (GIST) are rare mesenchymal tumors characterized by KIT or PDGFRA mutations. Over three decades, significant changes in drug discovery and loco-regional (LR) procedures have impacted treatment strategies. We assessed the evolution of treatment strategies for metastatic GIST patients treated in the three national coordinating centers of NetSarc, the French network of sarcoma referral centers endorsed by the National Institute of Cancers, from 1990 to 2018. The primary objective was to describe the clinical and biological profiles as well as the treatment modalities of patients with metastatic GIST in a real-life setting, including access to clinical trials and LR procedures in the metastatic setting. Secondary objectives were to assess (1) patients' outcome in terms of time to next treatment (TNT) for each line of systemic treatment, (2) patients' overall survival (OS), (3) evolution of patients' treatment modalities and OS according to treatment access: <2002 (pre-imatinib approval), 2002-2006 (pre-sunitinib approval), 2006-2014 (pre-regorafenib approval), post 2014, and (4) the impact of clinical trials and LR procedures on TNT and OS in the metastatic setting. 1038 patients with a diagnosis of GIST made in one of the three participating centers between 1990 and 2018 were included in the national prospective database. Among them, 492 patients presented metastasis, either synchronous or metachronous. The median number of therapy lines in the metastatic setting was 3 (range 0-15). More than half of the patients (55%) participated in a clinical trial during the course of their metastatic disease and half (51%) underwent additional LR procedures on metastatic sites. The median OS in the metastatic setting was 83.4 months (95%CI [72.7; 97.9]). The median TNT was 26.7 months (95%CI [23.4; 32.3]) in first-line, 10.2 months (95%CI [8.6; 11.8]) in second line, 6.7 months (95%CI [5.3; 8.5]) in third line, and 5.5 months (95%CI [4.3; 6.7]) in fourth line, respectively. There was no statistical difference in OS in the metastatic setting between the four therapeutic periods (log rank, p = 0.18). In multivariate analysis, age, AFIP Miettinen classification, mutational status, surgery of the primary tumor, participation in a clinical trial in the first line and LR procedure to metastatic sites were associated with longer TNT in the first line, whereas age, mitotic index, mutational status, surgery of the primary tumor and LR procedure to metastatic sites were associated with longer OS. This real-life study advocates for early reference of metastatic GIST patients to expert centers to orchestrate the best access to future innovative clinical trials together with LR strategies and further improve GIST patients' survival.

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

Simple Summary

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

Abstract

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

Surgical resection for patients with recurrent or metastatic gastrointestinal stromal tumors: a protocol for a systematic review and meta-analysis update

BACKGROUND

There are limited data on the clinical benefits of adding surgical resection in patients with recurrent or metastatic gastrointestinal stromal tumors (GISTs). This protocol outlines the planned scope and methods for a systematic review and meta-analysis update that will compare the clinical outcomes of surgical resection combined with tyrosine kinase inhibitor (TKI) with TKI treatment alone in patients with recurrent or metastatic GISTs.

METHODS

This review will update a previously published systematic review by our team. This protocol is presented in accordance with the PRISMA-P guideline. PubMed, Embase, and Cochrane Central Register of Controlled Trials will be systematically searched and supplemented by a secondary screening of the references of all included studies. We will include randomized controlled trials (RCTs) and non-randomized studies (NRS) in this review update. The outcomes evaluated will be overall survival and progression-free survival. Two reviewers will independently screen and select studies, extract data from the included studies, and assess the risk of bias of the included studies. Data extracted from RCTs and NRS will be analysed and reported separately. Preplanned subgroup analyses and sensitivity analyses are detailed within this protocol. The strength of the body of evidence will be assessed using GRADE.

DISCUSSION

This systematic review and meta-analysis update will provide a current assessment of the evidence for the role of surgery in patients with recurrent or metastatic advanced GISTs. These findings will be used by the Chinese Society of Clinical Oncology (CSCO) GIST guideline recommendations on surgical treatment for recurrent or metastatic advanced GIST patients in China.

SYSTEMATIC REVIEW REGISTRATION

This protocol was prospectively registered in the Open Science Framework Registry ( https://osf.io/xus7m ).

Immune-infiltration based signature as a novel prognostic biomarker in gastrointestinal stromal tumour

BACKGROUND

Accumulating evidence indicates that tumour-infiltrating lymphocytes (TILs) are the primary determinant of survival outcomes in various tumours. Thus, we sought to investigate the TIL distribution and density in gastrointestinal stromal tumours (GISTs) and to develop an immune infiltration (II)-based signature to predict prognosis.

METHODS

The expression of 8 immune features in the tumour centre (TC) and tumour margin (TM) and PD-L1 in 435 GIST patients was investigated by immunohistochemistry. Then, a 4-feature-based II-GIST signature integrating the CD3⁺ TC, CD3⁺ TM, CD8⁺ TM and CD45RO⁺ TM parameters was developed using a LASSO Cox regression model in the training cohort and was validated in two separate validation cohorts.

FINDINGS

High CD3⁺ TC, CD3⁺ TM, CD8⁺ TC, CD8⁺ TM, CD45RO⁺ TM, NKp46⁺ TM and CD20⁺ TM correlated with improved survival. Patients with high II-GIST scores have better RFS and OS outcomes than those with low II-GIST scores. Multivariable analyses demonstrated that the II-GIST signature is an independent prognostic factor. The receiver operating characteristic (ROC) curve demonstrated that the prognostic accuracy of the II-GIST signature is superior to that of the NIH risk criteria. Further analysis showed that moderate- and high-risk GIST patients with high II-GIST scores could gain survival benefits from adjuvant imatinib therapy.

INTERPRETATION

The novel II-GIST signature accurately predicted the survival outcomes of GIST patients. In addition, the II-GIST signature was a useful predictor of survival benefit from imatinib therapy amongst moderate- and high-risk patients with GIST.

FUNDING

This project was supported by National Natural Science Foundation of China (81702325), Natural Science Foundation of Guangdong Province (2017A030310565), and 3&3 Project of the First Affiliated Hospital of Sun Yat-sen University.

Revolutions in treatment options in gastrointestinal stromal tumours (GISTs): the latest updates

OPINION STATEMENT

The treatment of advanced GIST is rapidly evolving with the development of novel molecular compounds such as avapritinib and ripretinib, but also promising results have been achieved with cabozantinib in a phase II trial. The availability of over five lines of treatment for patients with advanced GIST is likely to completely shift the current second-line and third-line treatment options, and will also potentially enable a personalised approach to treatment. Imatinib will most likely remain as the first-line treatment of choice for the vast majority of GIST patients. However, for GIST patients with tumours harbouring a D842V mutation in PDGFRA exon 18, avapritinib has shown efficacy and will become first-line therapy for this molecular subgroup. For second- and third-line treatment, results are awaited of a number of clinical trials. However, second-line and further treatment could potentially be tailored depending on secondary mutations found in imatinib-resistant GISTs. As secondary resistance to TKIs remains the biggest challenge in the treatment of GIST and despite negative results with alternating regimens in phase II, combination treatments should be further evaluated to tackle this issue. Moreover, the favourable safety profiles observed with avapritinib and ripretinib suggest that combination treatments are feasible, for instance, combining two TKIs or a TKI with drugs targeting downstream signalling pathways, such as PI3K inhibitors or MEK inhibitors. Finally, in line with further personalisation of treatment in GIST, a multidisciplinary approach is essential, and local treatment options, such as RFA, resection in case of unifocal progression, and radiotherapy, should be considered.

Gastrointestinal stromal tumours (GISTs): French Intergroup Clinical Practice Guidelines for diagnosis, treatments and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO)

BACKGROUND

This document is a summary of the French Intergroup guidelines regarding the management of gastrointestinal stromal tumours (GISTs) updated in December 2018.

DESIGN

This collaborative work summarizes clinical practice recommendations (guidelines) on the management of GISTs. It is based on recent literature review, ESMO recommendations and expert opinions.

RESULTS

The diagnosis of GIST is based on histological examination and immunohistochemistry with markers KIT and DOG-1. Each case must be discussed within a multidisciplinary team. Complete surgical resection tumour, avoiding peroperative perforation, is the potentially curative treatment of localized GISTs. The estimation of the recurrence risk is essential, or adjuvant treatment,and follow-up adaptation. Genotyping (KIT and PDGFRA) of all but very low-risk GISTs is recommended. The nature of mutation has a prognostic value and predictive influence on drug efficacy. Imatinib, a tyrosine-kinase inhibitor, is the standard adjuvant treatment after R0 resection of a GIST with a high risk of recurrence, and the first line therapy for advanced GISTs. Suninitib and regorafenib are respectively the second- and third-line standard treatments for advanced GISTs.

CONCLUSION

Guidelines for management of GISTs are continuously evolving and need to be regularly updated. This constant progress is made possible through clinical and translational research.