Initial and late resistance to imatinib in advanced gastrointestinal stromal tumors are predicted by different prognostic factors: a European Organisation for Research and Treatment of Cancer-Italian Sarcoma Group-Australasian Gastrointestinal Trials Group study

Safety and efficacy of percutaneous image-guided ablation for soft tissue sarcoma metastases to the liver

PURPOSE

To evaluate outcomes following percutaneous image-guided ablation of soft tissue sarcoma metastases to the liver.

MATERIALS AND METHODS

A single-institution retrospective analysis of patients with a diagnosis of metastatic soft tissue sarcoma who underwent percutaneous image-guided ablation of hepatic metastases between January 2011 and December 2021 was performed. Patients with less than 60 days of follow-up after ablation were excluded. The primary outcome was local tumor progression-free survival (LPFS). Secondary outcomes included overall survival, liver-specific progression-free survival. and chemotherapy-free survival.

RESULTS

Fifty-five patients who underwent percutaneous ablation for 84 metastatic liver lesions were included. The most common histopathological subtypes were leiomyosarcoma (23/55), followed by gastrointestinal stromal tumor (22/55). The median treated liver lesions was 2 (range, 1-8), whereas the median size of metastases were 1.8 cm (0.3-8.7 cm). Complete response at 2 months was achieved in 90.5% of the treated lesions. LPFS was 83% at 1 year and 80% at 2 years. Liver-specific progression-free survival was 66% at 1 year and 40% at 2 years. The overall survival at 1 and 2 years was 98% and 94%. The chemotherapy-free holiday from the start of ablation was 71.2% at 12 months. The complication rate was 3.6% (2/55); one of the complications was Common Terminology Criteria for Adverse Events grade 3 or higher. LPFS subgroup analysis for leiomyosarcoma versus gastrointestinal stromal tumor suggests histology-agnostic outcomes (2 years, 89% vs 82%, p = .35).

CONCLUSION

Percutaneous image-guided liver ablation of soft tissue sarcoma metastases is safe and efficacious.

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.

Guideline-Based Follow-Up Outcomes in Patients With Gastrointestinal Stromal Tumor With Low Risk of Recurrence: A Report From the Italian Sarcoma Group

Importance

Gastrointestinal stromal tumor (GIST) follow-up is recommended by international guidelines, but data on the role of follow-up in patients with low relapse risk are missing. For these patients, the potential benefit of anticipating recurrence detection should be weighed against psychological burden and radiologic examination loads in terms of costs and radiation exposure.

Objective

To evaluate the outcomes of guideline-based follow-up in low-risk GIST.

Design, Setting, and Participants

This multi-institutional retrospective cohort study involving Italian Sarcoma Group reference institutions evaluated patients with GIST who underwent surgery between January 2001 and June 2019. Median follow-up time was 69.2 months. Data analysis was performed from December 15, 2022, to March 20, 2023. Patients with GIST at low risk according to Armed Forces Institute of Pathology criteria were included provided adequate clinical information was available: primary site, size, mitotic index, surgical margins, and 2 or more years of follow-up.

Exposures

All patients underwent follow-up according to European Society for Medical Oncology (ESMO) guidelines.

Main Outcomes and Measures

The primary outcome was the number of tests needed to identify a relapse according to ESMO guidelines follow-up plan. Secondary outcomes included relapse rate, relapse timing, disease-free survival (DFS), overall survival (OS), GIST-specific survival (GIST-SS), postrelapse OS, secondary tumor rates, and theoretical ionizing radiation exposure. An exploratory end point, new follow-up schedule proposal for patients with low-risk GIST according to the observed results, was also assessed.

Results

A total of 737 patients (377 men [51.2%]; median age at diagnosis, 63 [range, 18-86] years) with low-risk GIST were included. Estimated 5-year survival rates were 95.5% for DFS, 99.8% for GIST-SS, and 96.1% for OS. Estimated 10-year survival rates were 93.4% for DFS, 98.1% for GIST-SS, and 91.0% for OS. Forty-two patients (5.7%) experienced disease relapse during follow-up (9 local, 31 distant, 2 both), of which 9 were detected after 10 or more years. This translated into approximately 1 relapse detected for every 170 computed tomography scans performed, with a median radiation exposure of 80 (IQR, 32-112) mSv per patient. Nongastric primary tumor (hazard ratio [HR], 2.09; 95% CI, 1.14-3.83; P = .02), and KIT mutation (HR, 2.77; 95% CI, 1.05-7.27; P = .04) were associated with a higher risk of relapse. Second tumors affected 187 of 737 patients (25%), of which 56 were detected during follow-up and represented the primary cause of death in these patients.

Conclusions and Relevance

In this cohort study on patients affected by low-risk GISTs, the risk of relapse was low despite a follow-up across 10 or more years. These data suggest the need to revise follow-up schedules to reduce the anxiety, costs, and radiation exposure of currently recommended follow-up strategy.

Liver resection for metastatic GIST tumor improves survival in the era of tyrosine kinase inhibitors: a systematic review and meta-analysis

INTRODUCTION

Survival for gastrointestinal stromal tumor (GIST) has been increasing over the years after the introduction of tyrosine kinase inhibitors. However, the role of metastasectomy for GIST is still controversial. Patients are currently treated with imatinib or sunitinib in case of imatinib failures as optimal medical therapy for metastatic GIST.

METHODS

The Pubmed, EMBASE, and Cochrane Library were systematically searched. Overall survival following liver resection ± tyrosine kinase inhibitor treatment for metastatic GIST was compared to treatment with tyrosine kinase inhibitors alone.

RESULTS

Eleven studies including both randomized control trials and retrospective cohort studies were included in the final analysis with a total of 988 patients. Seven studies encompassed data on 556 patients with isolated liver metastases (219 surgery ± drug groups and 337 drug-only groups) were included. Overall survival was significantly improved in patients undergoing liver resection ± drug therapy in comparison to drug therapy alone. [HR (95%CI) = 2.10 (1.58, 2.79); p<0.00001]. Subgroup analysis showed that patients also had improved progression free survival based on 4 studies. [HR (95%CI) = 1.92 (1.43, 2.56); p<0.00001]. In case of concurrent liver and peritoneal metastases, patients showed improved overall survival with aggressive surgical approaches based on 10 studies. [HR (95%CI) = 1.90 (1.56, 2.31); p<0.00001].

CONCLUSION

This meta-analysis found that liver resection for patients with metastatic GIST regardless of peritoneal metastases improved progression free and overall survival in conjunction with tyrosine kinase inhibitors as compared with medical therapy alone. Furthermore, liver resections did not have any immediate detrimental impact on survival in the group of patients selected.

Improved Efficacy of First-Line Imatinib in Advanced Gastrointestinal Stromal Tumors (GIST): The Dutch GIST Registry Data

BACKGROUND

Patients with unresectable and metastasized gastrointestinal stromal tumor (GIST) experienced a remarkable improvement of progression-free survival (PFS) and overall survival (OS) after the introduction of imatinib. Our hypothesis is that the outcomes of treatment with imatinib are even better nowadays compared with the registration trials that were performed two decades ago. To study this, we used real-life data from a contemporary registry.

METHODS

A multicenter, retrospective study was performed by exploring clinical data from a prospective real-life clinical database, the Dutch GIST Registry (DGR). Patients with advanced GIST treated with first-line imatinib were included and PFS (primary outcome) and OS (secondary outcome) were analyzed. Results of our study were compared with published results of the European Organisation for Research and Treatment of Cancer (EORTC) 62005 trial, which marked the first era of imatinib in the treatment of GIST.

RESULTS

Overall, 420 of the 435 patients treated with imatinib in the DGR had recorded response evaluation and were included in the analysis. During a median follow-up of 35.0 months (range 2.0-136.0), progression of GIST was eventually observed in 217 patients (51.2%). The DGR cohort showed a longer median PFS (33.0 months, 95% confidence interval [CI] 28.4-37.6) compared with the EORTC 62005 trial (an estimated PFS of 19.5 months). Additionally, the median OS of 68.0 months (95% CI 56.1-80.0) was longer than the exposed median OS (46.8 months) published in the long-term follow-up results of the EORTC 62005 trial (median follow-up duration 10.9 years).

CONCLUSION

This study provides an update on outcomes of imatinib in the treatment of advanced GIST patients and demonstrates improved clinical outcomes since the first randomized studies of imatinib 2 decades ago. Furthermore, these results represent outcomes in real-world clinical practice and can serve as a reference when evaluating effectiveness of imatinib in patients with advanced GIST.

Surgical Options for Peritoneal Surface Metastases from Digestive Malignancies-A Comprehensive Review

The peritoneum is a common site for the dissemination of digestive malignancies, particularly gastric, colorectal, appendix, or pancreatic cancer. Other tumors such as cholangiocarcinomas, digestive neuroendocrine tumors, or gastrointestinal stromal tumors (GIST) may also associate with peritoneal surface metastases (PSM). Peritoneal dissemination is proven to worsen the prognosis of these patients. Cytoreductive surgery (CRS), along with systemic chemotherapy, have been shown to constitute a survival benefit in selected patients with PSM. Furthermore, the association of CRS with hyperthermic intraperitoneal chemotherapy (HIPEC) seems to significantly improve the prognosis of patients with certain types of digestive malignancies associated with PSM. However, the benefit of CRS with HIPEC is still controversial, especially due to the significant morbidity associated with this procedure. According to the results of the PRODIGE 7 trial, CRS for PSM from colorectal cancer (CRC) achieved overall survival (OS) rates higher than 40 months, but the addition of oxaliplatin-based HIPEC failed to improve the long-term outcomes. Furthermore, the PROPHYLOCHIP and COLOPEC trials failed to demonstrate the effectiveness of oxaliplatin-based HIPEC for preventing peritoneal metastases development in high-risk patients operated for CRC. In this review, we discuss the limitations of these studies and the reasons why these results are not sufficient to refute this technique, until future well-designed trials evaluate the impact of different HIPEC regimens. In contrast, in pseudomyxoma peritonei, CRS plus HIPEC represents the gold standard therapy, which is able to achieve 10-year OS rates ranging between 70 and 80%. For patients with PSM from gastric carcinoma, CRS plus HIPEC achieved median OS rates higher than 40 months after complete cytoreduction in patients with a peritoneal cancer index (PCI) ≤6. However, the data have not yet been validated in randomized clinical trials. In this review, we discuss the controversies regarding the most efficient drugs that should be used for HIPEC and the duration of the procedure. We also discuss the current evidence and controversies related to the benefit of CRS (and HIPEC) in patients with PSM from other digestive malignancies. Although it is a palliative treatment, pressurized intraperitoneal aerosolized chemotherapy (PIPAC) significantly increases OS in patients with unresectable PSM from gastric cancer and represents a promising approach for patients with PSM from other digestive cancers.

Advances in the research of the mechanism of secondary resistance to imatinib in gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. At present, surgery is the first-line treatment for primary resectable GISTs; however, the recurrence rate is high. Imatinib mesylate (IM) is an effective first-line drug used for the treatment of unresectable or metastatic recurrent GISTs. More than 80% of patients with GISTs show significantly improved 5-year survival after treatment; however, approximately 50% of patients develop drug resistance after 2 years of IM treatment. Therefore, an in-depth research is urgently needed to reveal the mechanisms of secondary resistance to IM in patients with GISTs and to develop new therapeutic targets and regimens to improve their long-term prognoses. In this review, research on the mechanisms of secondary resistance to IM conducted in the last 5 years is discussed and summarized from the aspects of abnormal energy metabolism, gene mutations, non-coding RNA, and key proteins. Studies have shown that different drug-resistance mechanism networks are closely linked and interconnected. However, the influence of these drug-resistance mechanisms has not been compared. The combined inhibition of drug-resistance mechanisms with IM therapy and the combined inhibition of multiple drug-resistance mechanisms are expected to become new therapeutic options in the treatment of GISTs. In addition, implementing individualized therapies based on the identification of resistance mechanisms will provide new adjuvant treatment options for patients with IM-resistant GISTs, thereby delaying the progression of GISTs. Previous studies provide theoretical support for solving the problems of drug-resistance mechanisms. However, most studies on drug-resistance mechanisms are still in the research stage. Further clinical studies are needed to confirm the safety and efficacy of the inhibition of drug-resistance mechanisms as a potential therapeutic target.

New response evaluation criteria using early morphological change in imatinib treatment for patients with gastrointestinal stromal tumor

BACKGROUND

The introduction of molecularly targeted drugs, including imatinib, has greatly improved the prognosis of gastrointestinal stromal tumor (GIST), and based on the different response image, the methods of response evaluation have been established for GISTs. Furthrmore, the best response evaluation using them has been reported to be associated with progression-free survival (PFS) in imatinib treatment. However, since it is more important to predict the clinical outcomes of imatinib treatment in "early treatment phase", new predicting factor in earlier stage is desired to work out the whole strategy of each patient. Early morphological change (EMC) was previously reported as a predictive marker for molecularly targeted drugs in metastatic colorectal cancer. The purpose of the present study was to verify the efficacy of EMC in predicting the outcome in patients with GIST receiving imatinib at early evaluation.

METHODS

We retrospectively reviewed 66 patients. EMC in computed tomography (CT) image was evaluated, and the patients were categorized into two groups: active MR (morphological response) (+) group and active MR (-) group. We investigated the association between the presence of active MR and clinical outcomes.

RESULTS

Forty-five patients had active MR ( +). The median progression-free survival (PFS) in patients with/without active MR was 49/23 months (P = 0.0039).

CONCLUSION

The evaluation criteria based on EMC could be a sensitive method to predict the clinical outcome of imatinib treatment for patients with unresectable GIST.

Cost-Effectiveness Analysis of Fourth- or Further-Line Ripretinib in Advanced Gastrointestinal Stromal Tumors

Background

The INVICTUS trial assessed the efficacy and safety of ripretinib compared with placebo in the management of advanced gastrointestinal stromal tumors.

Method

We used a Markov model with three health states: progression-free disease, progression disease and death. We parameterized the model from time-to-event data (progression-free survival, overall survival) of ripretinib and placebo arms in the INVICTUS trial and extrapolated to a patient’s lifetime horizon. Estimates of health state utilities and costs were based on clinical trial data and the published literature. The outcomes of this model were measured in quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs). Uncertainty was tested via univariate and probabilistic sensitivity analyses.

Results

The base-case model projected improved outcomes (by 0.29 QALYs) and additional costs (by $70,251) and yielded an ICER of $244,010/QALY gained for ripretinib versus placebo. The results were most sensitive to progression rates, the price of ripretinib, and health state utilities. The ICER was most sensitive to overall survival. When overall survival in the placebo group was lower, the ICER dropped to $127,399/QALY. The ICER dropped to $150,000/QALY when the monthly cost of ripretinib decreased to $14,057. Probabilistic sensitivity analyses revealed that ripretinib was the cost-effective therapy in 41.1% of simulations at the willingness-to-pay (WTP) threshold of $150,000.

Conclusion

As the fourth- or further-line therapy in advanced gastrointestinal stromal tumors, ripretinib is not cost-effective in the US. Ripretinib would achieve its cost-effectiveness with a price discount of 56% given the present effectiveness.

Monitoring Circulating Tumor DNA During Surgical Treatment in Patients with Gastrointestinal Stromal Tumors

The majority of patients diagnosed with advanced gastrointestinal stromal tumors (GISTs) are successfully treated with a combination of surgery and tyrosine kinase inhibitors (TKIs). However, it remains challenging to monitor treatment efficacy and identify relapse early. Here, we utilized a sequencing strategy based on molecular barcodes and developed a GIST-specific panel to monitor tumor-specific and TKI resistance mutations in cell-free DNA and applied the approach to patients undergoing surgical treatment. Thirty-two patients with GISTs were included, and 161 blood plasma samples were collected and analyzed at routine visits before and after surgery and at the beginning, during, and after surgery. Patients were included regardless of their risk category. Our GIST-specific sequencing approach allowed detection of tumor-specific mutations and TKI resistance mutations with mutant allele frequency < 0.1%. Circulating tumor DNA (ctDNA) was detected in at least one timepoint in nine of 32 patients, ranging from 0.04% to 93% in mutant allele frequency. High-risk patients were more often ctDNA positive than other risk groups (P < 0.05). Patients with detectable ctDNA also displayed higher tumor cell proliferation rates (P < 0.01) and larger tumor sizes (P < 0.01). All patients who were ctDNA positive during surgery became negative after surgery. Finally, in two patients who progressed on TKI treatment, we detected multiple resistance mutations. Our data show that ctDNA may become a clinically useful biomarker in monitoring treatment efficacy in patients with high-risk GISTs and can assist in treatment decision making.

Gastrointestinal stromal tumor of the small intestine with lung metastasis

Gastrointestinal stromal tumours (GISTs) represent 1% of primary gastrointestinal cancers. These tumors most frequently metastasise to the liver and peritoneum and rarely to the lungs. We report the case of a 79-year-old woman with gastrointestinal stromal tumor of the small intestine and pulmonary metastases. Contrast-enhanced computed tomography (CT) revealed a focal mass centered around the last intestinal loop associated with pulmonary bilateral masses. The diagnosis of gist of the small bowel was confirmed by histopathological and immunohistochemical analyses of bioptic material obtained from CT guided biopsy of pulmonary lesions. To the best of our knowledge, only few cases had been reported in medical literature as This mode of presentation is unusual, with computed tomography (CT) playing a significant role in the diagnosis and management.

Imatinib-Resistant Gastrointestinal Stromal Tumor Presenting as a Large Abdominal Mass

Gastrointestinal stromal tumors (GISTs) are the stromal or mesenchymal neoplasms affecting the gastrointestinal tract. Although they constitute 1% of primary gastrointestinal tumors, they are the most common nonepithelial tumors involving the gastrointestinal tract. They mostly present as overt or occult gastrointestinal bleeding. We present a case in which a 77-year-old female presented with a large abdominal mass. The origin of the mass was unclear on CT and MRI scan of the abdomen. Upper gastrointestinal endoscopic ultrasonography showed a cystic lesion in the perigastric region. A fine-needle biopsy of the lesion was performed, which was consistent with spindle type GIST. After the initial failure of imatinib therapy, the tumor was managed surgically.

Gastrointestinal stromal tumor with maxillary metastasis: a case report and literature review

Gastrointestinal stromal tumors (GISTs) form commonly in the stomach, small intestine, colorectum, and esophagus. Metastatic GIST occurs in up to 50% of patients at presentation. The liver and peritoneal cavity are the most common (93%) metastatic sites; head and neck metastases are extremely rare. This report describes a unique case of a 77-year-old man who was diagnosed with a duodenal GIST that had been completely resected 15 years ago. Eleven years after complete resection, he presented with liver metastases and then received multiple lines of systemic therapy and ablative radiotherapy. In 2015, he presented to our oral and maxillofacial surgery department with a left exophytic maxillary mass that filled the left maxillary sinus. Incisional biopsy confirmed metastatic GIST. Further evaluation revealed extensive metastases in the patient's liver, lungs, spleen, abdominal wall, and lymph nodes. After adequate staging, the patient's condition was deemed palliative, and he was referred to the radiation oncology department for palliative treatment of the symptomatic maxillary lesion. To our knowledge, this is the first reported case of maxillary metastasis from a duodenal GIST. Inclusion of GIST in the differential diagnosis of jaw tumors in patients with nonoral malignancies is recommended. The literature on oral metastasis of GIST is reviewed and discussed in this case report.

An updated review of the treatment landscape for advanced gastrointestinal stromal tumors

Before the introduction of tyrosine kinase inhibitors (TKIs), the overall survival of patients with advanced or metastatic gastrointestinal stromal tumors (GISTs) was 10 to 20 months because of the lack of approved therapies. In the last 20 years, a treatment algorithm for patients with advanced GISTs, which includes imatinib, sunitinib, and regorafenib as first‐, second‐, and third‐line therapies, respectively, has been established. Recently, 2 new TKIs have been approved: ripretinib for fourth‐line therapy and avapritinib as first‐line therapy in patients harboring platelet‐derived growth factor receptor α (PDGFRA) exon 18 D842V mutations. Additionally, there are several experimental therapies under investigation that could advance individualized patient care. All of these therapies have varying efficacies and safety profiles that warrant an updated treatment landscape review. This review article summarizes the efficacy and safety data currently available for conventional TKIs along with recently approved and experimental therapies.

With evolving treatment options and effective toxicity management, patients with advanced gastrointestinal stromal tumors are living longer than ever before. Recently approved targeted therapies and the investigation of experimental treatment options have the potential to alter the current treatment algorithm and encourage personalized patient care.

Therapeutic Potential of PI3K/AKT/mTOR Pathway in Gastrointestinal Stromal Tumors: Rationale and Progress

Simple Summary

Most gastrointestinal stromal tumors (GISTs) arise due to gain-of-function mutations of KIT and PDGFRA, encoding the receptor tyrosine kinase (RTK). The introduction of the RTK inhibitor imatinib has significantly improved the management of GISTs; however, drug resistance remains a challenge. Constitutive autophosphorylation of RTKs is associated with the activation of the PI3K/AKT/mTOR pathway. Especially, this pathway plays a pivotal role in mRNA translation initiation, directly regulated by eukaryotic initiation factors (eIFs). This review highlights the progress for targeting PI3K/AKT/mTOR-dependent mechanisms in GISTs and explores the relationship between mTOR downstream eIFs and the development of GISTs, which may be a promising future therapeutic target for this tumor entity.

Abstract

Gastrointestinal stromal tumor (GIST) originates from interstitial cells of Cajal (ICCs) in the myenteric plexus of the gastrointestinal tract. Most GISTs arise due to mutations of KIT and PDGFRA gene activation, encoding the receptor tyrosine kinase (RTK). The clinical use of the RTK inhibitor imatinib has significantly improved the management of GIST patients; however, imatinib resistance remains a challenge. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is a critical survival pathway for cell proliferation, apoptosis, autophagy and translation in neoplasms. Constitutive autophosphorylation of RTKs has an impact on the activation of the PI3K/AKT/mTOR pathway. In several preclinical and early-stage clinical trials PI3K/AKT/mTOR signaling inhibition has been considered as a promising targeted therapy strategy for GISTs. Various inhibitory drugs targeting different parts of the PI3K/AKT/mTOR pathway are currently being investigated in phase Ι and phase ΙΙ clinical trials. This review highlights the progress for PI3K/AKT/mTOR-dependent mechanisms in GISTs, and explores the relationship between mTOR downstream signals, in particular, eukaryotic initiation factors (eIFs) and the development of GISTs, which may be instrumental for identifying novel therapeutic targets.

Establishment of patient-derived xenografts from patients with gastrointestinal stromal tumors: analysis of clinicopathological characteristics related to engraftment success

Patient-derived xenografts (PDXs) can represent the heterogeneity and histological characteristics of tumors and are thus useful for testing the efficacy of anti-cancer drugs; however, PDXs are difficult to generate, especially for gastrointestinal stromal tumor (GIST). We analyzed the clinicopathologic factors associated with the successful establishment of GIST PDX in NOD.Cg-Prkdc^scid IL2rg^tm1Wjl/SzJ mice. We used 185 GIST tumor fragments from patients who underwent surgical resection prior to (n = 66; 35.7%) and after treatment (n = 119; 64.3%) with tyrosine kinase inhibitors. The overall success rate of PDX establishment was 17%; in univariate analysis, engraftment success was associated with after TKI treatment, larger tumor size, higher mitotic count, higher Ki-67 index, higher cellularity, presence of tumor necrosis, primary mutations in KIT exon 11, and originating from metastatic lesions. In multivariate analysis, higher Ki-67 index, after TKI treatment, and larger tumor size were independent factors for engraftment success. Immunohistochemistry in representative samples further corroborated the above results. These results will be useful in the establishment of PDX models from GISTs.

Progress in determining response to treatment in gastrointestinal stromal tumor

Introduction: Gastrointestinal stromal tumor (GIST) is the most common malignant mesenchymal tumor of the gastrointestinal system. Multiple advances in the management of GIST from the discovery of KIT/PDGRA and other genetic alterations have led to the development of multiple tyrosine kinase inhibitors. Response assessment in GIST is determined with iRECIST (Response Evaluation Criteria in Solid Tumors), PERCIST (PET response criteria in solid tumors), or Choi criteria. Molecular genotyping of the tissue samples is the recent standard for diagnosis, treatment, and response to treatment.Areas covered: In this study, we provide a brief overview of the history of the GIST, molecular sequencing, available treatment options and clinical trials, radiologic response assessment, and the role of ctDNA in response evaluation.Expert opinion: Future GIST management is related to the development of sensitive assays to detect genetic alterations for initial diagnosis, treatment selection, monitoring the response to treatment, resistant mutations, and predicting survival.

The Use of Molecular Subtypes for Precision Therapy of Recurrent and Metastatic Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumor in the digestive tract. Tyrosine kinase inhibitors (TKIs), represented by imatinib, sunitinib, and regorafenib, have become the main treatment for recurrent and metastatic GISTs. With the wide application of mutation analysis and the precision medicine, molecular characteristics have been determined that not only predict the prognosis of patients with recurrent and metastatic GISTs, but also are closely related to the efficacy of first-, second- and third-line TKIs for GISTs, as well as other TKIs. Despite the significant effects of TKIs, the emergence of primary and secondary resistance ultimately leads to treatment failure and tumor progression. Currently, due to the signal transmission of KIT/PDGFRA during onset and tumor progression, strategies to counteract drug resistance include the replacement of TKIs and the development of new drugs that are directed towards carcinogenic mutations. In addition, it is also the embodiment of precision medicine for GISTs to explore new carcinogenic mechanisms and develop new drugs relying on new biotechnology. Surgery can benefit specific patients but its major purpose is to diminish the resistant clones. However, the prognosis of recurrent and metastatic patients is still unsatisfactory. Therefore, it is worth paying attention to how to maximize the benefits for patients.

Prognostic value of systemic inflammatory marker in patients with head and neck squamous cell carcinoma undergoing surgical resection

Aim: To explore the prognostic value of the systemic inflammatory marker (SIM) based on neutrophil, lymphocyte and monocyte counts in head and neck squamous cell carcinoma (HNSCC) patients. Patients & methods: We retrospectively collected the data of 367 patients with HNSCC who underwent surgery. The Kaplan-Meier survival analysis and Cox regression analysis were conducted on disease-free survival and overall survival. Results: A high SIM (>1.34) was associated with larger tumor size, advanced clinical stage and shorter survival time. The survival analysis showed that only clinical stage and SIM were independent prognostic indicators of disease-free survival and overall survival. Conclusion: The SIM positively correlated with tumor progression and might be a powerful prognostic indicator of poor outcome in patients with HNSCC.

Preoperative imatinib treatment in patients with locally advanced and metastatic/recurrent gastrointestinal stromal tumors: A single-center analysis

The advent of imatinib mesylate (IM) has dramatically revolutionized the prognosis of advanced and metastatic/recurrent gastrointestinal stromal tumors (GISTs). The objective of this retrospective study is to investigate the safety and efficacy of combination of surgery following IM treatment in the management of advanced and metastatic/recurrent GISTs. We further explore the long-term clinical outcomes in these who underwent therapy of preoperative IM.Eligible patients with GISTs before the onset of the IM therapy and were periodically followed up in the outpatient clinic were included in this study. Detailed clinical and pathologic characteristics were obtained from the medical records of our institution. Univariate and multivariate regression analyses were performed to use for the evaluation of potential prognostic factors.A total of 51 patients were included in the study, of these patients, 36 patients underwent surgery and median duration of preoperative IM is 8.2months (range 3.5-85 months). Significant median tumor shrinkage rate was 29.27% (95% confidence interval 21.00%-34.00%) observed in these patients who responded to IM, and partial response and stable disease were achieved in 24 patients (47.06%) and 23 patients (45.10%), respectively, in light of the RECIST guideline (version 1.1). After the median follow-up of 43.70 months (range 14.2-131.1 months), 1- and 3-year overall survival (OS) were estimated to be 96.1% and 94.0%, respectively, and there was a significant improvement in OS for patients who received surgical intervention versus those who did not.Our study consolidates that patients were received preoperative IM therapy could shrink the size of tumors and facilitate organ-function preservation. The long-term analysis on this study supports that surgical intervention following IM therapy benefits for patients with primary advanced and recurrent or metastatic GISTs on long-term prognosis.

Role of Resection Following Focal Progression with Standard Doses of Imatinib in Patients with Advanced Gastrointestinal Stromal Tumors: Results of Propensity Score Analyses

BACKGROUND

There are limited data on the clinical benefits of adding surgical resection in patients with focally progressive gastrointestinal stromal tumor (GIST). This study aims to compare the clinical outcomes of resection plus imatinib dose escalation or maintenance (S group) with imatinib dose escalation alone (NS group) in patients with advanced GIST following focal progression (FP) with standard doses of imatinib.

MATERIALS AND METHODS

A total of 90 patients with advanced GISTs who experienced FP with standard doses of imatinib were included in this retrospective analysis. The primary endpoints were time to imatinib treatment failure (TTF) and overall survival (OS).

RESULTS

Compared with the NS group (n = 52), patients in the S group (n = 38) had a higher proportion of primary tumor site involvement and lower tumor burden at FP. With a median follow-up duration of 31.0 months, patients in the S group had significantly better TTF and OS than patients in the NS group (median TTF: 24.2 vs. 6.5 months, p < .01; median OS: 53.2 vs. 35.1 months, p = .009). Multivariate analysis showed that S group independently demonstrated better TTF (hazard ratio [HR], 0.29; p < .01) and OS (HR, 0.47; p = .01). Even after applying inverse probability of treatment-weighting adjustments, S group demonstrated significantly better TTF (HR, 0.36; p < .01) and OS (HR, 0.58; p = .049).

CONCLUSION

Our results suggested that resection following FP with standard doses of imatinib in patients with advanced GIST provides additional benefits over imatinib dose escalation alone.

IMPLICATIONS FOR PRACTICE

This is the first study to compare the clinical outcomes of resection plus imatinib dose escalation or maintenance (S group) with imatinib dose escalation alone (NS group) in patients with advanced gastrointestinal stromal tumor (GIST) following focal progression (FP) with standard doses of imatinib. These findings suggest that resection can be safely performed following FP, and the addition of surgical resection provides further clinical benefit over imatinib dose escalation alone. Based on these results, the authors recommend resection following FP in patients with advanced GIST provided that an experienced multidisciplinary team is involved in the patient's treatment.

Proteomic research in sarcomas - current status and future opportunities

Sarcomas are a rare group of mesenchymal cancers comprising over 70 different histological subtypes. For the majority of these diseases, the molecular understanding of the basis of their initiation and progression remains unclear. As such, limited clinical progress in prognosis or therapeutic regimens have been made over the past few decades. Proteomics techniques are being increasingly utilised in the field of sarcoma research. Proteomic research efforts have thus far focused on histological subtype characterisation for the improvement of biological understanding, as well as for the identification of candidate diagnostic, predictive, and prognostic biomarkers for use in clinic. However, the field itself is in its infancy, and none of these proteomic research findings have been translated into the clinic. In this review, we provide a brief overview of the proteomic strategies that have been employed in sarcoma research. We evaluate key proteomic studies concerning several rare and ultra-rare sarcoma subtypes including, gastrointestinal stromal tumours, osteosarcoma, liposarcoma, leiomyosarcoma, malignant rhabdoid tumours, Ewing sarcoma, myxofibrosarcoma, and alveolar soft part sarcoma. Consequently, we illustrate how routine implementation of proteomics within sarcoma research, integration of proteomics with other molecular profiling data, and incorporation of proteomics into clinical trial studies has the potential to propel the biological and clinical understanding of this group of complex rare cancers moving forward.

Predictive factors for toxicity and survival of second-line sunitinib in advanced gastrointestinal stromal tumours (GIST)

Introduction: Sunitinib is a standard second-line treatment in advanced gastrointestinal stromal tumours (GIST). We aimed to search for predictive factors for grade 3 and 4 toxicity, progression-free survival (PFS) and overall survival (OS) in a GIST reference center patient population, outside clinical trials.Methods: A retrospective analysis was performed of patients treated in two European Comprehensive Cancer Centers between January 2005 and December 2015. Demographic and clinical features, tumour characteristics and biological parameters were investigated. Logistic regression models were used to find factors associated with grade 3 and 4 toxicity. To identify predictive factors for PFS and OS, variables that were statistically significant in univariate analysis were used in the multivariate Cox proportional hazards model.Results: Ninety-one patients were included in this analysis. Age >60 years (HR 5.0, p = .006) and body weight ≤70 kg (HR 4.7, p = .009) were predictive factors for grade 3 and 4 toxicity. When divided into two categories, non-haematological grade 3 and 4 toxicity was predicted by age >60 years (HR 3.8, p = .012) and body weight ≤70 kg (HR 3.3, p = .025) whereas haematological toxicity had no significantly associated predictive factors. The median PFS and OS with sunitinib were 8.8 months and 27.5 months, respectively. The use of imatinib less than six months compared to 6-12 months (HR 0.2, p = .013) and to >12 months (HR 0.3, p = .016) and liver and/or peritoneal metastases (HR 0.1, p < .001, HR 0.2, p = .003 and HR 0.2, p = .004) compared to locally advanced disease only were predictive for longer PFS. High neutrophil (HR 3.1, p = 0.04) and platelet count (HR 2.4, p = .046) predicted a shorter OS. Flexible sunitinib dosing was associated with superior OS (p = .021).Conclusion: In advanced GIST patients treated with sunitinib, older and low-weight patients are at risk for grade 3 and 4 toxicity. Clinical (prior imatinib use and metastases), biological (neutrophil and platelet count) and treatment characteristics independently predict PFS and OS.

Pre-treatment inflammatory biomarkers predict early treatment response and favorable survival in patients with metastatic colorectal cancer who underwent first line cetuximab plus chemotherapy

Objective

This study was to determine whether peripheral blood biomarkers including neutrophil‑lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and systemic immune inflammation index (SII) could predict early response to cetuximab; moreover, the prognostic ability of those biomarkers on progression free survival (PFS) and overall survival (OS) of metastatic colorectal cancer (mCRC) patients with wild-type (WT) RAS was also investigated.

Methods

mCRC patients with WT RAS treated with cetuximab plus chemotherapy were retrospectively analyzed, and early response was evaluated according to RECIST 1.1 after three or four treatment cycles. In prior to chemotherapy, hematologic data and clinic-pathological parameters were collected. The associations between pre-treatment inflammatory biomarkers and early response, and the prognostic value of those biomarkers were analyzed. A total of 102 patients were enrolled and divided into low or high NLR, PLR, and SII groups, respectively.

Results

The early response rate was significantly higher in the low NLR (p<0.001), low PLR (p=0.045), and low SII (p=0.011), respectively. In multivariate analyses, primary tumor resection (hazard ratio (HR) 0.411, p<0.001), carcino-embryonic antigen ≤5 ng/mL (HR 0.406, p<0.001), early treatment response (HR 0.322, p<0.001), and low NLR (HR 0.665, p=0.031) were independent factors of longer PFS. Primary tumor resection (HR 0.488, p=0.003) and early response (HR 0.392, p<0.001) were independent factors of longer OS. Further analysis showed that patients with early response, even in the high groups, can achieve better PFS and OS than non-responders.

Conclusion

Pre-treatment inflammatory biomarkers, especially NLR were predictors of benefit from cetuximab-combined therapy in mCRC patients. They were also predictors of significantly longer PFS and OS of early responders compared to non-responders.

[Imatinib and beyond-what is important for surgery?]

The treatment of gastrointestinal stromal tumors (GIST) has dramatically improved since the introduction of small molecule KIT proto-oncogene receptor tyrosine kinase inhibitors. Nevertheless, the cure of patients is still based on surgical treatment of the primary tumor. The chance of long-term tumor control by tyrosine kinase inhibitors (TKI) even in the metastatic setting also appears to be improved after achieving a surgical complete resection. The decision on which patients will most likely profit from multimodal treatment approaches is increasingly based on complex molecular predictors in addition to clinical factors and also a profound understanding of the biology of GIST that requires discussion in a multidisciplinary, highly experienced treatment team. Novel, more potent inhibitors enable a response to treatment in so far treatment-refractory GIST subtypes, such as the platelet-derived growth factor receptor (PDGFR) D842V mutated GIST subtype and also appear to show treatment benefits even in KIT mutated GIST after the failure of all approved treatments. These treatments are expected to profoundly change treatment algorithms in the near future.

Prognostic value of the pretreatment neutrophil-to-lymphocyte ratio in patients with advanced gastrointestinal stromal tumors treated with sunitinib after imatinib failure

The neutrophil-to lymphocyte ratio (NLR) has been proven to be correlated with outcomes in various cancer types, including gastrointestinal stromal tumors (GIST). There is limited data regarding the clinical value of NLR during second line therapy after failure of imatinib and there is an urgent need for more precise predictive factors for therapy. The aim of this study was to assess the association of the pretreatment NLR with progression free survival (PFS) and overall survival (OS) in patients with unresectable/metastatic GIST treated with sunitinib in a second line of treatment. In this analysis 146 out of 230 patients with unresectable/metastatic GIST were included, who were treated between 2005 and 2016 with sunitinib after failure of imatinib, with complete clinical data. In all patients, the NLR was assessed at baseline. The NLR cutoff of 2.4 was selected. The Kaplan-Meier method with the long-rank test and Cox proportional hazards model were applied for statistical analysis. Median PFS was 12.4 months with a 2-year rate of 27.1% and a 5-year rate of 4.8%. Median OS was 22.8 months, whereas 2- and 5-year rates were 47.8 and 13.8%, respectively. Patients with NLR>2.4 had significantly shorter OS: Median OS was 30 months for NLR≤2.4 vs. 16.4 months for NLR>2.4 (P=0.002); median PFS was 18.2 vs. 9.6 (P=0.075), respectively. In a multivariate model adjusted for mitotic index, primary location of tumor and driver mutation in KIT exon 11, NLR was proven to be independently associated with OS (HR 1.92, 95% CI 1.27-2.9, P=0.002) but not PFS (HR 1.31, 95%CI 0.89-1.93, P=0.17). The present data demonstrate that NLR can serve as an independent prognostic factor for patients with advanced GIST treated with sunitinib.

Relationship between efficacy of sunitinib and KIT mutation of patients with advanced gastrointestinal stromal tumors after failure of imatinib: A systematic review

BACKGROUND

A large number of studies have shown that KIT mutations are closely related to the prognosis of gastrointestinal stromal tumors (GISTs). At the same time, sunitinib (SU) has become the second-line recommended drug for GISTs because of its efficacy. We initiated a systematic review to compare the efficacy of SU after failure of Imatinib (IM) in different KIT mutations.

METHODS

We searched for SU-treated patients with advanced GISTs after failed IM treatment by using databases such as PubMed, EMBASE, and the Cochrane Library, up to March 2018. We conducted statistical analyses to calculate the odds ratio (OR), hazard ratio (HR), and 95% confidence interval (CI) using fixed-effects and random-effects models by Review Manager 5.3 software.

RESULTS

We included a total of 474 patients from 3 retrospective studies and 2 cohort studies. Patients with exon 9 mutations had higher clinical benefit (OR = 2.61, 95% CIs = 1.32-5.18, P = .006) rates and longer progression-free survival (progressive disease, HR = 0.51, 95% CIs = 0.36-0.72, P = .0001) compared with exon 11, but there was no statistically significant difference in overall survival (OS, HR = 0.93, 95% CIs = 0.34-2.55, P = .89) and there was greater heterogeneity (Tau = 0.72, Chi = 21.45, df = 3, P < .001, I = 86%). Subgroup analysis suggests that race may be one of the sources of heterogeneity.

CONCLUSION

The results show that efficacy of SU is closely associated with KIT genotypes in GISTs. Moreover, racial factor also directly affects the prognosis of different KIT mutational status, so GISTs patients of different genotypes might also consider the use of targeted drugs in consideration of ethnic differences.

Clinical outcomes of imatinib dose escalation versus sunitinib in first-line imatinib-failure gastrointestinal stromal tumour

AIM

The majority of available data on the clinical efficacy of sunitinib in patients with imatinib-resistant or -intolerant gastrointestinal stromal tumours (GISTs) are from studies of western populations. We investigated the clinical outcomes of imatinib dose escalation versus sunitinib in first-line imatinib-failure Asian GIST patients to further guide clinical treatment.

METHODS

Patients received imatinib dose escalation and a shift to sunitinib (Group A) or a direct shift to sunitinib (Group B). The objective tumour response was assessed according to Choi's criteria. Progression-free survival (PFS) and overall survival (OS) were calculated. The relationship between genetic mutation and survival was analysed.

RESULTS

In total, 40 patients who fulfilled the inclusion criteria were recruited. The differences in survival between Group A and Group B were not significant for PFS (p = .776) or OS (p = .219). For patients with KIT exon 11 mutation, a trend towards a better PFS was found in Group B (p = .122), OS of Group B was better than Group A (p = .013). The median PFS and OS of sunitinib treatment were 8 and 24 months, respectively, and a clinical benefit was observed in 80%. Patients with KIT exon 11 mutations had better PFS compared to those with KIT exon 9 mutations or wild-type GISTs (p = .017, p = .040, respectively).

CONCLUSIONS

Both imatinib dose escalation and sunitinib were optional in Asian patients after failure of first-line imatinib, and patients with KIT exon 11 mutation benefited more from a direct shift to sunitinib.

Long-term survival outcome with tyrosine kinase inhibitors and surgical intervention in patients with metastatic or recurrent gastrointestinal stromal tumors: A 14-year, single-center experience

The long‐term effects of tyrosine kinase inhibitors (TKIs), including imatinib, and surgical intervention on advanced gastrointestinal stromal tumor (GIST) were evaluated. All 379 patients had metastatic or recurrent GIST and started 400 mg/d imatinib at the Asan Medical Center in periods 1 and 2 [2001‐2007 (33.2%) and 2008‐2014 (66.8%), respectively]. Men constituted 60.4%; median patient age and tumor size at the initiation of imatinib were 58.6 (14.6‐85.5) years and 51 (0‐324) mm, respectively, without differences between periods except for older age and less preimatinib surgery in period 2. Response and disease control rates with imatinib in measurable GIST were 63.1% and 94.3%, respectively, without differences between periods. More patients in period 2 underwent surgical resection for TKI‐responsive diseases within the first 2 years (24.9%, P = 0.006). With a median follow‐up of 6.1 years (2.5‐16.0) in survivors, median progression‐free survival (PFS) was 5.4 years [95% confidence interval (CI), 4.0‐6.9]. Subsequent sunitinib (P = 0.066) and regorafenib (P = 0.003) were more commonly administered in period 2. Median overall survival (OS) was 8.8 years (95% CI, 7.8‐9.7). PFS with imatinib (P = 0.002) and OS (P = 0.019) were significantly longer in period 2. Young age, smaller tumor size at the initiation of imatinib, KIT exon 11 mutation, surgical intervention, and period 2 were favorable factors for PFS and OS. Patients with advanced GIST showed better prognosis with the optimal use of imatinib, along with active surgical intervention and more common use of subsequent TKIs in period 2.

Complete response to sunitinib for more than three years in a patient with a jejunum gastrointestinal stromal tumor: A case report

RATIONALE

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract and is characterized by KIT mutations. Patientsresistant to 1st-line imatinib therapy are usually given sunitinib assecond-line treatment, which provides a median progression-free survival of 8 to 12 months. We report the 1st case of metastatic jejunum GIST with a KIT exon 11 deletion that showed complete response (CR) to sunitinib for more than 3 years.

PATIENT CONCERNS

A 34-year-old man with advanced jejunum GIST was surgically treated upon initial diagnosis, and was histologically found to carry a high recurrence risk. Genetic testing revealed a KIT exon 11 deletion, and adjuvant therapy with imatinib was administered. The imatinib dose was escalated following recurrence in the abdomen, but the mass continued to grow.

DIAGNOSIS

He was diagnosed with abdominal recurrence of GIST based on his medical history and histopathological results.

INTERVENTION

Second-line sunitinib therapy was given.

OUTCOMES

The mass disappeared, and CR was seen following 7 months of sunitinib therapy; this CR was sustained for more than 45 months.

LESSONS

In cases of metastatic jejunum GIST with a KIT exon 11 deletion, sunitinib as second-line therapy can be used to achieve CR for more than 3 years.

Cytological Findings of Gastrointestinal Stromal Tumor-Derived Bone Metastasis

OBJECTIVE

Procedures for diagnosing bone tumors should be rapid and minimally invasive. Thus, cytological examinations are more useful for such purposes than histological examinations. In order to identify cytomorphological findings that could be used to diagnose bone metastasis from gastrointestinal stromal tumors (GIST), previous cases were reviewed.

STUDY DESIGN

Cytological samples of 7 lesions from 4 patients with GIST-derived bone metastasis, which were obtained from 2001 to 2017 at the JFCR Cancer Institute Hospital, were reviewed.

RESULTS

The metastasis of GIST to the bone was clinically suspected before the cytological and histological examinations in all cases since they all involved other metastatic lesion(s), and characteristic osteolytic lesions were detected on radiological images. Although various cell shapes were encountered, spindle cell proliferation was seen in all cytological samples. No pleomorphism was apparent. Characteristic nuclear findings were observed. All of the cases could be diagnosed as GIST-derived bone metastasis.

CONCLUSION

GIST-derived bone metastasis can be diagnosed by examining cytological samples.

Genomic Subtypes of GISTs for Stratifying Patient Response to Sunitinib following Imatinib Resistance: A Pooled Analysis and Systematic Review

Objectives

Sunitinib (a second-line chemotherapeutic agent that inhibits multiple kinases, including KIT and PDGFR) is widely used in imatinib-resistant patients with gastrointestinal stromal tumors (GISTs). However, diverse responses to sunitinib have been observed in the clinic. We aimed to evaluate whether the different GIST genotypes could be used to stratify patient response to sunitinib.

Methods

We searched the PubMed, Embase, and Cochrane databases and included English-language literature published up to August 31, 2017. Inclusion criteria were GIST patients with KIT exon 9, KIT exon 11, or PDGFRA mutations and those without KIT/PDGFRA mutations (termed the wild-type genotype) who were receiving sunitinib within a clinical trial, and the efficacy evaluation was clinical benefit rate (CBR), median progression-free survival (PFS), and overall survival (OS). Odds ratios (ORs) for CBR and hazard ratios (HRs) for PFS and OS with 95% confidence intervals (CIs) in sunitinib-treated GIST patients with different genotypes were compared.

Results

Seven studies totaling 531 patients were included. Patients with KIT mutations showed an improved CBR to sunitinib compared to those with PDGFRA mutations. In particular, those with the KIT exon 9 or 11 mutation showed improved CBR over those with PDGFRA mutation. Moreover, GIST patients with the KIT exon 9 mutation showed improved CBR over those with the KIT exon 11 mutation. Patients without KIT/PDGFRA mutations (wild-type genotype) showed better CBR than those with PDGFRA mutations.

Conclusion

GIST genotypes may be useful for stratifying patient response to sunitinib after imatinib resistance.

Blood neutrophil-to-lymphocyte ratio is associated with prognosis in advanced gastrointestinal stromal tumors treated with imatinib

INTRODUCTION

Neutrophil-to-lymphocyte ratio (NLR) was shown to be prognostic in several solid malignancies. There are limited data about predictive/prognostic value of NLR during targeted therapy of patients with advanced gastrointestinal stromal tumors (GIST). The aim of this study was to asses a clinical value of this ratio in patients with advanced GIST.

METHODS

Between 2001 and 2016, 385 patients with metastatic/unresectable GIST treated initially with imatinib were included in the analysis. In all patients, the NLR was assessed at the baseline, after 3 months of treatment, and upon disease progression (or last observation). The cutoff values for NLR were set at 2.7 and 5.4. Kaplan-Meier survival probability estimation with log-rank test and Cox proportional hazards model were used for analysis.

RESULTS

Median progression-free survival (PFS) on imatinib treatment was 44.8 months, 5-year rate 43%; median overall survival (OS) 87.2 months, 10-year rate 36.3%. NLR >2.7 at baseline was significantly associated with poorer OS and PFS: median OS was 89.3 months (95% confidence interval [CI] 80.2-115) for NLR ratio ≤2.7 vs 59.4 months (95% CI 48.6-82) for NLR >2.7 (p < .001); median PFS was 59.4 vs 32.7 (p < .001), respectively. In multivariate model adjusted for mitotic index and driver mutation in the tumor (KIT exon 11 mutation versus other), NLR ratio was proven to be statistically significant (hazard ratio 1.09; 95% CI 1.01-1.19; p = .030). Among patients with disease progression, NLR >2.7 assessed at the third month of treatment was linked with significantly shorter median time to progression (7.5 vs 19 months).

CONCLUSIONS

Our results demonstrate the usefulness of NLR as a prognostic and predictive marker as well as a marker for treatment monitoring in patients with advanced GIST treated with imatinib.

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.

Predictive value of inflammatory indexes on the chemotherapeutic response in patients with unresectable lung cancer: A retrospective study

Chemotherapy is widely administered to patients with advanced lung cancer; however, data regarding chemotherapeutic sensitivity are limited. The present study aimed to investigate the predictive value of inflammatory indexes for chemotherapeutic efficacy in advanced lung cancer. Patients with stage III and IV unresectable lung cancer that were treated with first-line chemotherapy between January 2007 and December 2011 were retrospectively identified, and chemotherapeutic response was evaluated following 2 or 3 chemotherapy cycles. Prior to chemotherapy, hematologic data and clinicopathological parameters were collected using electronic medical records. The associations between the main inflammatory indexes [which included the pretreatment neutrophil count (PNC), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR)] and the chemotherapeutic efficacy, as well as the prognostic value of the indexes, were analyzed. According to the receiver operating characteristic curve, PLR failed to reach diagnostic accuracy for overall chemotherapeutic response. PNC and NLR were each classified into two groups according to the cut-off values (4.635×10⁹/l for PNC and 2.443 ×10⁹/l for NLR). The overall response rate was significantly higher in the low PNC [odds ratio, 3.261; 95% confidence interval (CI), 2.102-5.060; P<0.001, vs. high PNC] and low NLR groups (odds ratio, 1.596; 95% CI, 1.037-2.454; P=0.033, vs. high NLR). Univariate analyses showed that the high PNC (HR, 1.487) and high NLR groups (HR, 1.288) were associated with poor progression-free survival (PFS); however, NLR was considered statistically insignificant in multivariate analysis. In summary, high PNC and NLR values are associated with chemoresistance and an unfavorable prognosis, with the present study demonstrating that PNC has increased sensitivity when compared with other inflammatory indexes in predicting chemotherapeutic efficacy. Therefore, PNC has the potential to be used as a reliable and suitable predictor to stratify a high risk of chemoresistance in patients with stage III and IV unresectable lung cancer.

Genetic polymorphisms in angiogenesis-related genes are associated with worse progression-free survival of patients with advanced gastrointestinal stromal tumours treated with imatinib

BACKGROUND

Imatinib 400 mg per day is first-line therapy for patients with gastrointestinal stromal tumours (GISTs). Although clinical benefit is high, progression-free survival (PFS) is variable. This study explores the relationship of single nucleotide polymorphisms (SNPs) in genes related to imatinib pharmacokinetics and pharmacodynamics and PFS in imatinib-treated patients with advanced GIST.

METHODS

In 227 patients a pharmacogenetic pathway analysis was performed. Genotype data from 36 SNPs in 18 genes were tested in univariate analyses to investigate their relationship with PFS. Genetic variables which showed a trend (p < 0.1) were tested in a multivariate model, in which each singular SNP was added to clinicopathological factors.

RESULTS

In univariate analyses, PFS was associated with synchronous metastases (p = 0.0008) and the mutational status (p = 0.004). Associations with rs1870377 in KDR (additive model, p = 0.0009), rs1570360 in VEGFA (additive model, p = 0.053) and rs4149117 in SLCO1B3 (mutant dominant model, 0.027) were also found. In the multivariate model, significant associations and trends with shorter PFS were found for synchronous metastases (HR 1.94, p = 0.002), KIT exon 9 mutation (HR 2.45, p = 0.002) and the SNPs rs1870377 (AA genotype, HR 2.61, p = 0.015), rs1570360 (AA genotype, HR 2.02, p = 0.037) and rs4149117 (T allele, HR 0.62, p = 0.083).

CONCLUSION

In addition to KIT exon 9 mutation and synchronous metastases, SNPs in KDR, VEGFA and SLCO1B3 appear to be associated with PFS in patients with advanced GIST receiving 400-mg imatinib. If validated, specific SNPs may serve as predictive biomarkers to identify patients with an increased risk for progressive disease during imatinib therapy.

Dovitinib in patients with gastrointestinal stromal tumour refractory and/or intolerant to imatinib

Background:

This multicentre phase II trial (DOVIGIST) evaluated the antitumour activity of dovitinib as second-line treatment of patients with gastrointestinal stromal tumour (GIST) refractory to imatinib or who do not tolerate imatinib.

Methods:

Patients received oral dovitinib 500 mg day⁻¹, 5 days on/2 days off, until GIST progression or unacceptable toxicity, with an objective to evaluate efficacy, assessed as the disease control rate (DCR) at 12 weeks. Tumour assessment and response to dovitinib therapy were evaluated by Response Evaluation Criteria In Solid Tumours (RECIST v1.1) and the Choi criteria. Secondary objectives included assessment of progression-free survival (PFS), safety and tolerability, and DCR at the end of treatment.

Results:

Thirty-eight of the 39 patients enrolled had histologically confirmed GIST. The DCR at 12 weeks was 52.6% (90% confidence interval (CI), 38.2–66.7%) meeting the preset efficacy criterion for the primary end point. The objective response rate (complete response+partial response) was 2.6% (1 of 38; 90% CI, 0.1–11.9%), and 5.3% (n=2; 90% CI, 0.9–15.7%) at the end of the study. The median PFS was 4.6 months (90% CI, 2.8–7.4 months). Dose interruption was required in 26 patients (66.7%), of which 18 (69.2%) were due to adverse events. The most frequently observed grade 3 adverse events included hypertension (n=7), fatigue (n=5), vomiting (n=4), hypertriglyceridaemia (n=4), and γ-glutamyltransferase increase (n=4).

Conclusions:

Dovitinib is an active treatment for patients with GIST who are intolerant to imatinib or whose GIST progresses on imatinib.

Ten-Year Progression-Free and Overall Survival in Patients With Unresectable or Metastatic GI Stromal Tumors: Long-Term Analysis of the European Organisation for Research and Treatment of Cancer, Italian Sarcoma Group, and Australasian Gastrointestinal Trials Group Intergroup Phase III Randomized Trial on Imatinib at Two Dose Levels

Purpose

To report on the long-term results of a randomized trial comparing a standard dose (400 mg/d) versus a higher dose (800 mg/d) of imatinib in patients with metastatic or locally advanced GI stromal tumors (GISTs).

Patients and Methods

Eligible patients with advanced CD117-positive GIST from 56 institutions in 13 countries were randomly assigned to receive either imatinib 400 mg or 800 mg daily. Patients on the 400-mg arm were allowed to cross over to 800 mg upon progression.

Results

Between February 2001 and February 2002, 946 patients were accrued. Median age was 60 years (range, 18 to 91 years). Median follow-up time was 10.9 years. Median progression-free survival times were 1.7 and 2.0 years in the 400- and 800-mg arms, respectively (hazard ratio, 0.91; P = .18), and median overall survival time was 3.9 years in both treatment arms. The estimated 10-year progression-free survival rates were 9.5% and 9.2% for the 400- and 800-mg arms, respectively, and the estimated 10-year overall survival rates were 19.4% and 21.5%, respectively. At multivariable analysis, age (< 60 years), performance status (0 v ≥ 1), size of the largest lesion (smaller), and KIT mutation (exon 11) were significant prognostic factors for the probability of surviving beyond 10 years.

Conclusion

This trial was carried out on a worldwide intergroup basis, at the beginning of the learning curve of the use of imatinib, in a large population of patients with advanced GIST. With a long follow-up, 6% of patients are long-term progression free and 13% are survivors. Among clinical prognostic factors, only performance status, KIT mutation, and size of largest lesion predicted long-term outcome, likely pointing to a lower burden of disease. Genomic and/or immune profiling could help understand long-term survivorship. Addressing secondary resistance remains a therapeutic challenge.

Impact of a risk-based follow-up in patients affected by gastrointestinal stromal tumour

BACKGROUND

Follow-up aims to precociously identify recurrences, metastases or treatment-related adverse events so as to undertake the appropriate therapy. Guidelines admit lack of knowledge on optimal surveillance schedule, but suggest follow-up based on experts' opinion and risk stratification. To identify the impact, if any, of regular follow-up, we interrogated our prospectively collected database whether early detection of recurrences affected both clinical management and, likely, the outcome.

PATIENTS AND METHODS

We required information to be available on primary surgery and ≥3°years of follow-up for non-recurring patients. We analysed recurrence characteristics (asymptomatic versus symptomatic, low- versus high tumour burden) and computed tomography (CT) scan counts to detect one recurrence. Kaplan-Meier method estimated recurrence-free survival (RFS), post-recurrence progression-free survival (PR-PFS), and disease-specific overall survival (OS). Comparisons used Hazard ratios (HR) with 95% confidence intervals (CIs). Multivariate analyses employed the Cox proportional hazards model. All tests were two-sided.

RESULTS

Between 01/2001 and 12/2012 we found 233 study-eligible patients. Estimated 5- and 10-year RFS were 61.8% and 50.4%, respectively. After a 68-month median follow-up, we observed 94 (40.3%) recurrences [73/94 (77.7%) asymptomatic versus 21/94 (22.3%) symptomatic and 45/94 (47.9%) low- versus 49/94 (52.1%) high tumour burden]. Multivariate analysis revealed that symptomatic and high tumour burden recurrences were highly predictive of both worse PR-PFS (HR:3.19, P < 0.001; HR:2.80, P = 0.003, respectively) and OS (HR:3.65, P < 0.001; HR:2.38, P = 0.026, respectively). Finally, 29 second (primary) cancers were detected during follow-up.

CONCLUSIONS

Regular follow-up detects recurrences at an earlier stage and may be associated with a better PR-PFS and OS for these patients. In the absence of randomised trials, these evidences support follow-up effort and cost.

Giant gastric gastrointestinal stromal tumor with severe peritoneal dissemination controlled by imatinib therapy following debulking surgery: a case report

BACKGROUND

At the time of diagnosis, giant gastric gastrointestinal stromal tumors are sometimes associated with severe peritoneal dissemination. Unresectable gastrointestinal stromal tumors are considered a systemic disease; therefore, imatinib therapy is currently the primary treatment option in these cases.

CASE PRESENTATION

A 49-year-old Japanese woman was referred to our hospital with symptoms of anorexia, abdominal discomfort, and a palpable abdominal mass. Contrast-enhanced computed tomography revealed a huge mass with an irregular wall, approximately 22 cm in size, located between the posterior gastric wall and her pancreas. The tumor grew rapidly, and her abdominal symptoms worsened; therefore, a semi-urgent laparotomy was performed. The tumor had arisen from her upper stomach and was removed by wedge resection of her stomach. In addition, widely distributed multiple white nodules were noted, which were resected as far as possible. Immunohistochemical staining of the resected specimen was positive for KIT and CD34. The resected white nodules contained the same cells as the primary tumor. Based on these pathological findings, a final diagnosis of a gastric gastrointestinal stromal tumor with peritoneal dissemination was made. Imatinib was administered at 400 mg per day from 1 month postoperatively. The disease progression of the residual disseminated lesions was favorably controlled, and our patient is now doing well, 12 months after surgery.

CONCLUSIONS

Imatinib therapy following debulking surgery can show dramatic effectiveness in giant gastric gastrointestinal stromal tumors with severe peritoneal dissemination.

Sunitinib in the treatment of gastrointestinal stromal tumor: patient selection and perspectives

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. In advanced setting and after progression to imatinib, the multi-targeted receptor tyrosine kinase inhibitor sunitinib has clearly demonstrated a clinical benefit in terms of response rate and progression-free survival with an acceptable toxicity profile. The recommended schedule for sunitinib administration is 50 mg per day 4 weeks ON and 2 weeks OFF; however, potential alternative schedules are also reviewed in the present article. Several biomarkers have been explored to better select candidates for sunitinib therapy, such as the value of early changes in standardized uptake value assessed by positron emission tomography with ¹⁸F-fluorodeoxyglucose, circulating biomarkers, clinical biomarkers such as the appearance of arterial hypertension during treatment that correlates with better outcomes, and the GIST genotype. GISTs with KIT mutations at exon 9 and the so-called wild-type GISTs seem to better respond to sunitinib. Nonetheless, further investigation is required to confirm these findings as well as to understand the mechanisms of sunitinib resistance such as the development of new KIT mutations or conformational changes in KIT receptor.

Promising novel therapeutic approaches in the management of gastrointestinal stromal tumors

Primary and secondary resistance to currently available licensed tyrosine kinase inhibitors poses a real clinical challenge in the management of advanced gastrointestinal stromal tumors. Within the frame of early phase clinical trials novel systemic treatments are currently being evaluated to target both the well explored and novel emerging downstream effectors of KIT and PDGFRA signaling. Alternative therapeutic approaches also include exploring novel inhibitors of the KIT/PDGFRA receptors, immune checkpoint and cyclin-dependent kinase inhibitors. The final clinical trial outcome data for these agents are highly anticipated. Integration of new diagnostic techniques into routine clinical practice can potentially guide tailored delivery of agents in the treatment of a highly polyclonal, heterogeneous disease such as heavily pretreated advanced gastrointestinal stromal tumor.

Molecular subtypes of gastrointestinal stromal tumors and their prognostic and therapeutic implications

Gastrointestinal stromal tumors (GISTs) are composed of various molecular subtypes, with differing prognostic and predictive relevance. Previously, tumors lacking mutations in the KIT and PDGFRA genes have been designated as 'wild-type' GISTs; however, they represent a heterogeneous group currently undergoing further subclassification. Primary and secondary resistance to imatinib poses a significant clinical challenge, therefore ongoing research is trying to evaluate mechanisms to overcome resistance. Thorough understanding of the prognostic and predictive relevance of different genetic subtypes of GIST can guide clinical decision-making both in the adjuvant and the metastatic setting. Further work is required to identify tailored therapies for specific subgroups of GISTs wild-type for KIT and PDGFRA mutations and to identify predictive factors of resistance to currently approved systemic therapies.

Indications for surgery in advanced/metastatic GIST

Gastrointestinal stromal tumours (GISTs) are a relatively rare entity and often present as a locally advanced tumour or with metastatic disease. Complete surgical resection is the only means of cure in localised disease; however, imatinib therapy has greatly advanced the management of GIST and is established as both an adjunct to surgery in high-risk cases and as principle therapy in metastatic disease. Surgery in advanced GIST has undergone a renaissance in recent years with the potential for a combined treatment approach with either neoadjuvant imatinib in locally advanced primary disease or as an adjunct to imatinib in those with metastases or recurrent disease. Neoadjuvant imatinib can render a locally advanced primary GIST resectable, allow less invasive procedures or promote preservation of function, especially if the tumour is located in an anatomically difficult position. The role of surgery in metastatic or recurrent disease is more controversial and case selection is critical. The potential benefit is difficult to quantify, although surgery may have a limited favourable impact on progression-free survival and overall survival for those patients whose disease is responding to imatinib or those with limited focal progression. Patients with imatinib resistant disease should not be offered surgery unless as an emergency where palliative intervention may be justified.

Correlation of KIT and PDGFRA mutational status with clinical benefit in patients with gastrointestinal stromal tumor treated with sunitinib in a worldwide treatment-use trial

Background

Several small studies indicated that the genotype of KIT or platelet-derived growth factor receptor-α (PDGFRA) contributes in part to the level of clinical effectiveness of sunitinib in gastrointestinal stromal tumor (GIST) patients. This study aimed to correlate KIT and PDGFRA mutational status with clinical outcome metrics (progression-free survival [PFS], overall survival [OS], objective response rate [ORR]) in a larger international patient population.

Methods

This is a non-interventional, retrospective analysis in patients with imatinib-resistant or intolerant GIST who were treated in a worldwide, open-label treatment-use study (Study 1036; NCT00094029) in which sunitinib was administered at a starting dose of 50 mg/day on a 4-week-on, 2-week-off schedule. Molecular status was obtained in local laboratories with tumor samples obtained either pre-imatinib, post-imatinib/pre-sunitinib, or post-sunitinib treatment, and all available data were used in the analyses regardless of collection time. The primary analysis compared PFS in patients with primary KIT exon 11 versus exon 9 mutations (using a 2-sided log-rank test) and secondary analyses compared OS (using the same test) and ORR (using a 2-sided Pearson χ² test) in the same molecular subgroups.

Results

Of the 1124 sunitinib-treated patients in the treatment-use study, 230 (20 %) were included in this analysis, and baseline characteristics were similar between the two study populations. Median PFS was 7.1 months. A significantly better PFS was observed in patients with a primary mutation in KIT exon 9 (n = 42) compared to those with a primary mutation in exon 11 (n = 143; hazard ratio = 0.59; 95 % confidence interval, 0.39–0.89; P = 0.011), with median PFS times of 12.3 and 7.0 months, respectively. Similarly, longer OS and higher ORR were observed in patients with a primary KIT mutation in exon 9 versus exon 11. The data available were limited to investigate the effects of additional KIT or PDGFRA mutations on the efficacy of sunitinib treatment.

Conclusions

This large retrospective analysis confirms the prognostic significance of KIT mutation status in patients with GIST. This analysis also confirms the effectiveness of sunitinib as a post-imatinib therapy, regardless of mutational status.

Trial registration

NCT01459757.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2051-5) contains supplementary material, which is available to authorized users.

Aggressive Surgical Resection Combined With Imatinib Therapy for Liver Metastases From a Gastrointestinal Stromal Tumor

The use of imatinib mesylate has influenced survival in patients with advanced gastrointestinal stromal tumors (GISTs). However, whether a combination of imatinib and surgical resection can further prolong survival in these patients has not yet been fully elucidated. We report a case of a 59-year-old woman with multiple liver metastases from a jejunal GIST. The patient received imatinib therapy after partial resection of the jejunum, and she subsequently underwent right hepatic trisectionectomy. However, liver metastasis was detected again after surgery. Secondary imatinib therapy was started, and the patient underwent partial hepatectomy at the left lateral segment. Postoperatively, the patient underwent imatinib treatment and has survived without recurrence for 3 years. Imatinib is recommended for the treatment of advanced GIST; however, a complete response is rare, and approximately half of all patients develop resistance to imatinib. Aggressive surgical resection combined with imatinib may be effective for the control of advanced GIST.