Gastrointestinal stromal tumours: ESMO-EURACAN Clinical Practice Guidelines for diagnosis, treatment and follow-up

Long-Term Outcomes of Gastric Subepithelial Lesion of < 2 cm and Risk Factors for Tumor Growth

BACKGROUND AND AIM

Endoscopic resection of small gastric subepithelial lesions (SELs) has been recently reported. However, evidence of natural history of untreated small gastric SELs is lacking. This study aimed to investigate the long-term course of gastric SELs of < 2 cm as well as identify the enlargement rate and factors affecting it.

METHODS

A total of 1045 gastric SELs in 1033 patients were evaluated via endoscopic ultrasonography (EUS) from January 1994 to December 2023. Of these, this study included 125 SELs in 122 patients with an initial tumor diameter of < 2 cm and who underwent at least two EUS examinations. Tumor diameter was measured through EUS and considered enlarged when the longitudinal diameter increased > 1.25 times from the initial size. Multivariate Cox proportional hazards regression analysis was used to identify factors affecting tumor enlargement.

RESULTS

The average observation period was 4.0 ± 3.4 years. A total of 29 (23.2%) lesions were enlarged during the observation period, with a mean tumor doubling time of 4.1 ± 3.8 years and an augmentation rate of 5.7/100 person-years. The multivariate analysis indicated that the initial tumor size of ≥ 9.5 mm (hazard ratio [HR]: 3.99, 95% confidence interval [CI]: 1.33-11.94) and EUS finding changes (irregular border, cystic space, high echoic lesion, and/or heterogeneity), excluding calcifications (HR: 2.55, 95% CI: 1.09-5.97), were increasing factors.

CONCLUSIONS

The augmentation rate of gastric SELs of < 2 cm was 5.7/100 person-years. These results provide valuable data for treatment decisions.

Concurrent Coprimary KIT Exon 17 and BRAF Mutations in a Small Intestinal GI Stromal Tumor-A Case Report

PURPOSE

Gastrointestinal stromal tumors (GISTs) are rare neoplasms driven by mutations in KIT, PDGFRA, or BRAF. Concomitant KIT/BRAF mutations are exceptionally rare and have historically been regarded as mutually exclusive. We report the first documented instance of a GIST with concurrent KIT exon 17 (D816H) and BRAF exon 15 (V600E) mutations, exploring the implications of these mutations for treatment and prognosis. KIT exon 17 mutations are rare and associated with imatinib resistance, and the literature on concurrent KIT/PDGFRA and BRAF mutations is limited, highlighting the potential of this case to provide valuable insights into the management of similar tumors.

METHODS

A 70-year-old woman presented with abdominal pain and a 20-year history of intermittent melena. Imaging and histopathological examination confirmed a duodenal GIST. The patient underwent en bloc tumor resection, and next-generation sequencing (NGS) identified co-occurring KIT exon 17 (D816H) and BRAF exon 15 (V600E) mutations. Postoperatively, the patient received adjuvant imatinib therapy for a planned duration of 3 years.

RESULTS

The patient tolerated adjuvant imatinib therapy well, experiencing only mild nausea and diarrhea. After 2 years of follow-up, no recurrence of the tumor was detected, and the patient remained in radiological remission with no signs of metastasis or tumor progression.

CONCLUSION

This case demonstrates a favorable outcome in a patient with localized GIST with concomitant KIT exon 17 and BRAF mutations following surgical resection with no evidence of recurrence. These findings underscore the significance of early comprehensive genotyping in GISTs to guide therapy and predict imatinib resistance.

The role for pancreatic preserving surgery for duodenal (D2) gastrointestinal stromal tumours

INTRODUCTION

A variety of surgical options are available to achieve a complete oncological resection for duodenal gastrointestinal stromal tumours (GISTs). The most common location of such tumours is the second portion (D2) of the duodenum. The key step in assessing the feasibility of localised duodenal resection is the relationship between the GIST and ampulla. We present our surgical approach and results for patients with D2 GISTs undergoing surgical resection at our tertiary oncology centre.

METHODS

Patients diagnosed with duodenal GIST involving D2 who underwent surgical resection at The Royal Marsden NHS Foundation Trust between March 2018 and May 2024 were included in this study.

RESULTS

11 patients with D2 GISTs were included in the study. The mean age was 60 ± 11.2 years. The majority (n = 9) of patients presented with gastrointestinal haemorrhage. The locations of duodenal GIST were D1/2 (n = 1), D2 (n = 8), and D2/3 (n = 2). 9 patients received neoadjuvant Imatinib treatment. 10 patients had peri-ampullary D2 GISTs resected with pancreatic preservation. There were no anastomotic or duodenotomy leaks. One patient developed delayed gastric emptying (DGE). One patient who underwent segmental D2/3 resection and duodeno-jejunostomy developed biliary obstruction and required PTC and biliary stent. One patient who presented with biliary obstruction underwent pancreaticoduodenectomy developed a Grade A post-operative pancreatic fistula. The median study follow-up was 38 months (range 3-72 months) and at the end of the study period only one patient had developed recurrence. All patients remain disease free and under active follow-up.

CONCLUSION

In summary, we demonstrate that for D2 GISTs presenting without biliary obstruction, localised D2 resection should be considered, and this approach is associated with low patient morbidity and good long-term patient outcomes.

Using body composition to predict treatment-related adverse events and disease-free survival in patients with gastrointestinal stromal tumors treated with imatinib: a retrospective cohort study

Background

Imatinib (IM) is the primary treatment for Gastrointestinal stromal tumor (GIST), but it faces significant challenges with resistance and a high incidence of adverse events. This study aims to assess the predictive value of baseline body composition parameters on treatment-related adverse events and disease-free survival (DFS) in GIST patients treated with imatinib.

Materials and Methods

A single-center retrospective analysis was conducted on 107 moderate or high-risk stratification GIST patients diagnosed from 2014 to 2020 at the First Affiliated Hospital of Nanjing Medical University. Body composition parameters, including skeletal muscle index (SMI), myosteatosis, cachexia index (CXI), and Fat-Free Mass (FFM), etc. were obtained using abdominal CT images and clinical data. Logistic and COX regression models were used to analyze the relationship between these indicators and treatment-related adverse events and DFS.

Results

Multivariate analysis revealed that myosteatosis (OR=7.640, P<0.001) and drug dose (OR=1.349, P=0.010) were independent risk factors for adverse events, while a higher CXI (OR=0.983, P=0.017) was protective. Additionally, LAMA/SMA% (OR=1.072, P=0.028) was identified as an independent risk factor for dose-limiting toxicity (DLT). Independent predictors of DFS included sarcopenia (HR=3.067, P=0.013), myosteatosis (HR=6.985, P=0.024), risk stratification (HR=9.562, high-risk vs. moderate-risk, P=0.003), and C-KIT mutation (HR=3.615, C-KIT exon 9 mutation vs. 11, P=0.013).

Conclusions

Baseline body composition parameters, particularly myosteatosis, effectively predict the adverse events and DFS in patients taking imatinib. Personalized treatment, such as targeted nutritional and exercise interventions, and close monitoring of patients with myosteatosis or sarcopenia can enhance compliance and improve survival rates.

Reopenable clip over-the-line method in endoscopic full-thickness resection of gastric submucosal tumors: A historical control study

OBJECTIVES

Endoscopic full-thickness resection for gastric submucosal tumors is gradually gaining popularity, and secure and amenable closure is key to its success. This study aimed to compare the reopenable clip over-the-line method with the purse-string method for defect closure after endoscopic full-thickness resection for gastric submucosal tumors.

METHODS

This historical control trial included 37 consecutive patients with 37 gastric submucosal tumors, who underwent endoscopic full-thickness resection between January 2021 and July 2024. All lesions were resected en bloc. After excluding three patients who underwent non-full-thickness resection, 34 patients were analyzed. Post-endoscopic full-thickness resection defects were closed using the purse-string method (n = 18) until 2022 and the reopenable clip over-the-line method (n = 16) from 2023.

RESULTS

The median (interquartile range) time for defect closure was longer in the reopenable clip over-the-line method group of 33 (31-57) min than in the purse-string method group of 26 (24-35) min (p = 0.013). The visual analog scale pain score at the umbilical region was lower (p = 0.048) after the reopenable clip over-the-line method than after the purse-string method. In the reopenable clip over-the-line method group, post-procedural abdominal pain was confined to the epigastrium, whereas it extended to the umbilical or left lateral regions in the purse-string method group. The reopenable clip over-the-line method group commenced the diet (p = 0.001) and discharged (p = 0.024) earlier than the purse-string method group.

CONCLUSIONS

Reopenable clip over-the-line method facilitated secure post-endoscopic full-thickness resection defect closure, reduced post-procedural abdominal pain, and shortened the fasting and hospitalization periods after endoscopic full-thickness resection in gastric submucosal tumors.

Feasibility and safety of endoscopic full-thickness resection for submucosal tumors in the upper gastrointestinal tract, including predominantly extraluminal submucosal tumors (with video)

OBJECTIVES

Endoscopic full-thickness resection (EFTR) for submucosal tumors (SMTs) has been technically challenging. This retrospective study aimed to evaluate the feasibility, safety, and efficacy of EFTR for upper gastrointestinal (GI) SMTs, including extraluminal lesions.

METHODS

We retrospectively investigated 232 patients with SMTs who underwent EFTR from January 2014 to August 2023. Clinicopathologic characteristics, procedure-related parameters, adverse events (AEs), and follow-up outcomes were assessed in all patients.

RESULTS

The en-bloc resection and en-bloc with R0 resection rates were 98.7% and 96.1%, respectively. The average endoscopic tumor size measured 17.2 ± 8.7 mm, ranging from 6 to 50 mm. The resection time and suture time were 49.0 ± 19.4 min and 22.5 ± 11.6 min, respectively. In all, 39 lesions (16.8%) exhibited predominantly extraluminal growth. Gastrointestinal stromal tumors (GISTs) were the predominant pathology, accounting for 78.4% of the cases. Twenty-one patients (9.1%) encountered complications, including pneumothorax (1/232, 0.43%), hydrothorax (1/232, 0.43%), localized peritonitis (3/232, 1.29%), and fever (16/232, 6.9%). Although the incidence of postoperative fever was notably higher in the predominantly extraluminal group (7/39, 17.9%) compared to the predominantly intraluminal group (9/193, 4.7%, P = 0.008), there were no significant differences in outcomes of the EFTR procedure. No instances of recurrence were observed during the mean follow-up period of 3.7 ± 2.3 years.

CONCLUSION

EFTR was found to be feasible, safe, and effective for resecting upper GI SMTs, including lesions with predominantly extraluminal growth. Further validation in a prospective study is warranted.

Development and validation of a machine-learning model for preoperative risk of gastric gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) have malignant potential, and treatment varies according to risk. However, no specific protocols exist for preoperative assessment of the malignant potential of gastric GISTs (gGISTs). This study aimed to use machine learning (ML) to develop and validate clinically relevant preoperative models to predict the malignant potential of gGISTs.

METHODS

This study screened patients diagnosed with gGISTs at the Affiliated Hospital of North Sichuan Medical College. Moreover, this study employed the Least Absolute Shrinkage and Selection Operator (LASSO) and logistic regression to identify risk factors. Subsequently, an ensemble of ML models was used to determine the optimal classifier. In addition, this study used SHapley Additive exPlanations (SHAP) for tailored risk profiling.

RESULTS

This study included 318 patients with gGISTs. Using LASSO regression and multifactorial logistic regression, this study analyzed the training dataset, revealing that the presence of endoscopic ultrasound (EUS) high-risk features, tumor border clarity, tumor diameter, and monocyte-to-lymphocyte ratio (MLR) were significant predictors of high malignancy risk in gGIST. As determined by our ML approach, the logistic classification model demonstrated optimal performance, with area under the receiver operating characteristic curves of 0.919 for the training set and 0.925 for the test set. Furthermore, decision curve analysis confirmed the clinical relevance of the model.

CONCLUSION

High-risk EUS features, ill-defined tumor margins, larger tumor diameters, and elevated MLR independently predicted increased malignant potential in gGIST. This study developed logistic regression models based on these factors, which were further interpreted using the SHAP methodology. This analytical approach facilitated personalized therapeutic decision-making among diverse patient populations.

Twenty-five years of experience with patient-reported outcome measures in soft-tissue sarcoma patients: a systematic review

PURPOSE

As the importance of the patient's perspective on treatment outcome is becoming increasingly clear, the availability of patient-reported outcome measures (PROMs) has grown accordingly. There remains insufficient information regarding the quality of PROMs in patients with soft-tissue sarcomas (STSs). The objectives of this systematic review were (1) to identify all PROMs used in STS patients and (2) to critically appraise the methodological quality of these PROMs.

METHODS

Literature searches were performed in MEDLINE and Embase on April 22, 2024. PROMs were identified by including all studies that evaluate (an aspect of) health-related quality of life in STS patients by using a PROM. Second, studies that assessed measurement properties of the PROMs utilized in STS patients were included. Quality of PROMs was evaluated by performing a COSMIN analysis.

RESULTS

In 59 studies, 39 PROMs were identified, with the Toronto Extremity Salvage Score (TESS) being the most frequently utilized. Three studies evaluated methodological quality of PROMs in the STS population. Measurement properties of the TESS, Quick Disability of the Arm, Shoulder and Hand (QuickDASH) and European Organization for Research and Treatment for Cancer Quality of Life Questionnaire (EORTC-QLQ-C30) were reported. None of the PROMs utilized in the STS population can be recommended for use based on the current evidence and COSMIN analysis.

CONCLUSION

To ensure collection of reliable outcomes, PROMs require methodological evaluation prior to utilization in the STS population. Research should prioritize on determining relevant content and subsequently selecting the most suitable PROM for assessment.

Identification and validation of protein biomarkers for predicting gastrointestinal stromal tumor recurrence

We conducted a proteomic analysis using mass spectrometry to identify and validate protein biomarkers for accurately predicting recurrence risk in gastrointestinal stromal tumors (GIST) patients, focusing on differentially expressed proteins in metastatic versus primary GIST tissues. We selected five biomarkers-GPX4, RBM4, TPM3, PFKFB2, and PGAM5-and validated their expressions in primary tumors of recurrent and non-recurrent GIST patients via immunohistochemistry. Our analysis of the association between these biomarkers with recurrence-free survival (RFS) and overall survival (OS), along with their interrelationships, revealed that immunohistochemistry confirmed significantly higher expressions of these biomarkers in primary GIST tissues of recurrent patients. Kaplan-Meier survival analysis showed that high expressions of GPX4, RBM4, TPM3, PFKFB2, and PGAM5 correlated with lower RFS, and GPX4 and RBM4 with lower OS. All biomarker pairs showed positive associations, with high expressions correlating with increased recurrence rates, and GPX4 and RBM4 with higher mortality rates. In conclusion, the biomarkers GPX4, RBM4, TPM3, PFKFB2, and PGAM5 are clinically relevant for predicting GIST recurrence, with their high expressions in primary tumors linked to poorer RFS and OS. They serve as potential prognostic indicators, enabling early treatment and improved outcomes. The observed interrelationships among these biomarkers further validate their accuracy in predicting GIST recurrence.

The benefit of surgery during systematic therapy for gastrointestinal stromal tumor liver metastasis: a SEER-based retrospective study

Background

The liver is the most common site of gastrointestinal stromal tumor (GIST) metastasis. Most patients who develop metastases gradually develop multiline drug resistance during long-term systematic treatment. We aimed to evaluate the benefit of surgery during the systematic treatment of GIST liver metastases.

Methods

Data on GISTs with liver metastasis were retrieved from the Surveillance, Epidemiology, and End Results database. This study included 607 patients, of whom 380 patients were treated with chemotherapy alone (Chemo group) and 227 patients underwent surgery in addition to chemotherapy (Chemo&Surg group). The primary outcomes were cancer-specific survival (CSS) and overall survival (OS). Propensity score matching (PSM) was performed to balance the baseline factors.

Results

According to the multivariate analysis, surgery benefitted both CSS and OS (P < 0.001). After PSM, surgical resection still showed significant benefits in terms of both CSS and OS (P < 0.001). Surgery combined with chemotherapy increased the median CSS by at least 63 months and the median OS by at least 76 months. Subgroup analysis of the Chemo&Surg group revealed that the timing of surgery was not an independent influencing factor for either CSS or OS.

Conclusions

We found that performing additional surgery, in addition to systematic therapy, for GIST liver metastasis resulted in improved CSS and OS. These benefits were not affected by the timing of surgery during systemic treatment.

Mean platelet volume/platelet count ratio can predict the recurrence-free survival rate of patients after complete resection of gastrointestinal stromal tumors

Purpose

The aim of this study is to compare mean platelet volume/platelet count ratio (PVPR) and other indicators' predictive abilities. Simultaneously, a new nomogram for predicting recurrence-free survival (RFS) after gastrointestinal stromal tumors (GISTs) R0 resection was developed.

Methods

From January 2010 to July 2019, 295 patients with GIST who were operated on at Harbin Medical University Cancer Hospital were retrospectively reviewed. With a 4-year RFS as the end point, using the Kaplan-Meier methods and log rank test, and then conducting Cox regression analysis, we compared and identified meaningful indicators for predicting prognosis. Finally, a nomogram was developed and validated using calibration curves.

Results

The receiver operating characteristic curve indicated that a cutoff point of 0.044 was the ideal threshold for PVPR, and patients were divided into a high-PVPR group (≤0.044) and a low-PVPR group (>0.044). Kaplan-Meier curves suggested that PVPR>0.044 had obvious associations with better RFS (p < 0.001). In accordance with multivariate analysis, PVPR (>0.044 vs. ≤0.044) (p = 0.005), National Institutes of Health (NIH) risk category (p < 0.001), and Ki-67 (p = 0.005) were the independent prognostic indicators of RFS. Tumor size, gastrointestinal bleeding, mitotic index, NIH risk category, CD34, and Ki-67 all exhibited an obvious correlation with PVPR (all p < 0.05). The nomogram's probability of concordance was 0.823, indicating that the nomogram predictions were well calibrated.

Conclusion

In GISTs, RFS can be independently predicted by PVPR. Patients with higher PVPR have better RFS. The nomogram including PVPR could be used to assist clinical treatment decision-making.

Levels of circulating tumor DNA correlate with tumor volume in gastro-intestinal stromal tumors: an exploratory long-term follow-up study

Patients with gastro-intestinal stromal tumors (GISTs) undergoing tyrosine kinase inhibitor therapy are monitored with regular computed tomography (CT) scans, exposing patients to cumulative radiation. This exploratory study aimed to evaluate circulating tumor DNA (ctDNA) testing to monitor treatment response and compare changes in ctDNA levels with RECIST 1.1 and total tumor volume measurements. Between 2014 and 2021, six patients with KIT proto-oncogene, receptor tyrosine kinase (KIT) exon-11-mutated GIST from whom long-term plasma samples were collected prospectively were included in the study. ctDNA levels of relevant plasma samples were determined using the KIT exon 11 digital droplet PCR drop-off assay. Tumor volume measurements were performed using a semi-automated approach. In total, 94 of 130 clinically relevant ctDNA samples were analyzed. Upon successful treatment response, ctDNA became undetectable in all patients. At progressive disease, ctDNA was detectable in five out of six patients. Higher levels of ctDNA correlated with larger tumor volumes. Undetectable ctDNA at the time of progressive disease on imaging was consistent with lower tumor volumes compared to those with detectable ctDNA. In summary, ctDNA levels seem to correlate with total tumor volume at the time of progressive disease. Our exploratory study shows promise for including ctDNA testing in treatment follow-up.

Case report: Male genital system, soft tissue and myocardial metastases in a patient with exon 11-mutated GIST of unknown origin

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal tumors of the gastrointestinal tract, usually arising in the stomach or in the small bowel. Most GISTs are diagnosed early due to the presence of symptoms (e.g., abdominal discomfort/pain, anemia, etc.); at times, diagnosis could be incidental (e.g., ultrasound or endoscopic examinations performed for other reasons, surgical intervention for a different disease, etc.). Diagnosis occurs when the tumor is already metastatic in 10-20% of cases. The most common metastatic sites are liver, peritoneum, and loco-regional lymph nodes. Here, we present the case of a male patient with an atypical presentation of disease: as a matter of fact, during his oncological history, he developed metastases in unlikely sites, such as penis, scrotum, myocardium, and soft tissues.

Safety, effectiveness and the optimal duration of preoperative imatinib in locally advanced gastric gastrointestinal stromal tumors: A retrospective cohort study

BACKGROUND

The optimal duration of preoperative imatinib (IM) remains controversial. This study aimed to evaluate the safety, therapeutic effectiveness, and optimal duration of preoperative IM in patients with locally advanced gastric gastrointestinal stromal tumors (GIST).

METHODS

The clinicopathologic data of 41 patients with locally advanced gastric GIST who received preoperative IM and underwent surgical resection from January 2014 and December 2021 were retrospectively analyzed.

RESULTS

After a median of 7.0 (IQR: 4.5-10) months of preoperative IM treatment, 30 patients experienced adverse events (AEs), 80% of which were grade 1/2 AEs. The mean tumor size decreased from 12.71 ± 5.34 cm to 8.26 ± 4.00 cm, with a reduction rate of 35%. Setting 8 months as the cut-off value according to the results of ROC analysis. The proportion of laparoscopic surgery was higher in patients with short-term (≤8 months) versus long-term (>8 months) preoperative IM. Compared with the subtotal/total gastrectomy group, patients in the local gastrectomy group exhibited less intraoperative blood loss, shorter length of postoperative hospital stay, and fewer postoperative complications. The 3-year recurrence-free survival (RFS) and overall survival (OS) rates were 82.9% and 97.6%, and the expected 5-year RFS and OS rates were 75.6% and 90.2% respectively. RFS was better in the short-term than in the long-term preoperative IM treatment group, and it was also better in pre- plus postoperative IM treatment group than that in the preoperative IM alone group. Both univariate and multivariate COX analysis showed that a higher mitotic index and long-term preoperative IM treatment were associated with worse RFS, while postoperative IM treatment could significantly improve RFS.

CONCLUSIONS

The study suggests that in patients with locally advanced gastric GIST, preoperative short-term (≤8 months) use of IM is associated with higher RFS than long-term use.

Molecular Profiling of KIT/PDGFRA-Mutant and Wild-Type Gastrointestinal Stromal Tumors (GISTs) with Clinicopathological Correlation: An 18-Year Experience at a Tertiary Center in Kuwait

In gastrointestinal stromal tumors (GISTs), identifying prototypical mutations in the KIT/PDGFRA oncogenes, or in rare alternate genes, is essential for prognostication and predicting response to tyrosine kinase inhibitors. Conversely, wild-type GISTs (WT-GIST), which lack known mutations, have limited treatment options. Data on the mutational landscape of GISTs and their impact on disease progression are very limited in Kuwait. Using a targeted next-generation sequencing panel, we investigated the spectrum and frequency of KIT, PDGFRA, and RAS-pathway-related mutations in 95 out of 200 GISTs diagnosed at Kuwait Cancer Center from 2005 to 2023 and assessed their correlation with clinicopathological parameters. Among the 200 tumors (median age 55 years; 15-91), 54% originated in the stomach, 33% in the small bowel, 7% in the colorectum, 1.5% in the peritoneum, and 4.5% had an unknown primary site. Of the 95 molecularly profiled cases, 88% had a mutation: KIT (61%), PDGFRA (25%), NF1 (2%), and one NTRK1 rearrangement. Ten WT-GISTs were identified (stomach = 6, small bowel = 2, and colorectum = 2). WT-GISTs tended to be smaller (median 4.0 cm; 0.5-8.0) (p = 0.018), with mitosis ≤5/5 mm2, and were of lower risk (p = 0.019). KIT mutations were an adverse indicator of disease progression (p = 0.049), while wild-type status did not significantly impact progression (p = 0.934). The genetic landscape in this cohort mirrors that of global studies, but regional collaborations are needed to correlate outcomes with genetic variants.

A systematic review and meta-analysis of neoadjuvant imatinib use in locally advanced and metastatic gastrointestinal stromal tumors

BACKGROUND

Several doubts remain regarding the optimal use of neoadjuvant imatinib in gastrointestinal stromal tumors (GISTs), such as ideal treatment duration, patient selection, and long-term survival outcomes. This manuscript provides a comprehensive review on neoadjuvant imatinib treatment outcomes and facilitate evidence-based decision-making for the use of imatinib therapy in GISTs.

METHODS

Four databases (PubMed, EMBASE, Scopus, and Cochrane Library) were searched from inception to September 9, 2023. Meta-analyses of proportions were performed for the outcomes of R0 resection, disease responses, and 1-year, 3-year, and 5-year overall survival (OS) as well as 1-year, 3-year, and 5-year disease free survival (DFS). Sensitivity analyses in the form of leave-one-out analyses, meta-regression, and subgroup analyses were performed for outcomes with substantial statistical heterogeneity.

RESULTS

The search yielded 1254 articles, and 36 studies were included in our analysis. Meta-analysis of proportions revealed that 1-year, 3-year, and 5-year OS was 100%, 94%, and 88%, while 1-year, 3-year and 5-year DFS was 99%, 89%, and 79%, respectively. An R0 resection rate of 89% and a disease response rate of 67% was achieved after a mean duration of treatment of 8.41 ± 0.367 months. KIT exon 9 mutation was significantly associated with poorer 5-year DFS.

CONCLUSION

This study quantified key outcomes for neoadjuvant imatinib in locally advanced and metastatic or recurrent GIST. Patients with gastric and rectal tumous stand to benefit from neoadjuvant imatinib with an optimal treatment duration of 8 months. Furthermore, the potential utility of mutational analysis in guiding treatment with neoadjuvant imatinib was demonstrated.

Pathological Complete Response After Neoadjuvant Imatinib in a Recurrent Duodenal Gastrointestinal Stromal Tumor (GIST)

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal neoplasms of the gastrointestinal (GI) tract. Although surgery is the treatment of choice in resectable disease, neoadjuvant therapy is indicated in advanced, metastatic, and recurrent tumors. Decreasing tumor burden may facilitate resection and reduce surgical morbidity. We describe a case of a 66-year-old male with a recurrent duodenal GIST, after surgery and adjuvant imatinib five years before. Following neoadjuvant therapy with imatinib for 12 months, the patient underwent a cephalic pancreaticoduodenectomy, without complications. The final histopathology showed a pathological complete response (pCR) with no residual neoplasm. A pathological complete response to imatinib in a recurrent disease is extremely rare. Molecular testing should be performed before neoadjuvant therapy to identify response-predictive mutations. In recurrent/metastatic disease, systemic therapy is the standard treatment for all patients. Surgery should be considered in a tailored approach in patients with good responses to systemic therapy before developing therapeutic resistance.

Efficacy of real-time artificial intelligence-aid endoscopic ultrasonography diagnostic system in discriminating gastrointestinal stromal tumors and leiomyomas: a multicenter diagnostic study

Background

Gastrointestinal stromal tumors (GISTs) represent the most prevalent type of subepithelial lesions (SELs) with malignant potential. Current imaging tools struggle to differentiate GISTs from leiomyomas. This study aimed to create and assess a real-time artificial intelligence (AI) system using endoscopic ultrasonography (EUS) images to differentiate between GISTs and leiomyomas.

Methods

The AI system underwent development and evaluation using EUS images from 5 endoscopic centers in China between January 2020 and August 2023. EUS images of 1101 participants with SELs were retrospectively collected for AI system development. A cohort of 241 participants with SELs was recruited for external AI system evaluation. Another cohort of 59 participants with SELs was prospectively enrolled to assess the real-time clinical application of the AI system. The AI system's performance was compared to that of endoscopists. This study is registered with Chictr.org.cn, Number ChiCT2000035787.

Findings

The AI system displayed an area under the curve (AUC) of 0.948 (95% CI: 0.921-0.969) for discriminating GISTs and leiomyomas. The AI system's accuracy (ACC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) reached 91.7% (95% CI 87.5%-94.6%), 90.3% (95% CI 83.4%-94.5%), 93.0% (95% CI 87.2%-96.3%), 91.9% (95% CI 85.3%-95.7%), and 91.5% (95% CI 85.5%-95.2%), respectively. Moreover, the AI system exhibited excellent performance in diagnosing ≤20 mm SELs (ACC 93.5%, 95% CI 0.900-0.969). In a prospective real-time clinical application trial, the AI system achieved an AUC of 0.865 (95% CI 0.764-0.966) and 0.864 (95% CI 0.762-0.966) for GISTs and leiomyomas diagnosis, respectively, markedly surpassing endoscopists [AUC 0.698 (95% CI 0.562-0.834) for GISTs and AUC 0.695 (95% CI 0.546-0.825) for leiomyomas].

Interpretation

We successfully developed a real-time AI-assisted EUS diagnostic system. The incorporation of the real-time AI system during EUS examinations can assist endoscopists in rapidly and accurately differentiating various types of SELs in clinical practice, facilitating improved diagnostic and therapeutic decision-making.

Funding

Science and Technology Commission Foundation of Shanghai Municipality, Science and Technology Commission Foundation of the Xuhui District, the Interdisciplinary Program of Shanghai Jiao Tong University and the Research Funds of Shanghai Sixth people's Hospital.

Endoscopic full-thickness resection for gastric submucosal tumors: Japanese multicenter prospective study

OBJECTIVES

Early gastric cancer endoscopic resection (ER) is prominent in Japan. However, evidence regarding ER of gastric submucosal tumors (SMT) is limited. This prospective multicenter phase II study investigated the efficacy and safety of endoscopic full-thickness resection (EFTR) for gastric SMT.

METHODS

Endoscopic full-thickness resection indication for gastric SMT was 11-30 mm, histologically proven or clinically suspicious (irregular margin, increasing size, or internal heterogeneity) gastrointestinal stromal tumors (GIST), with no ulceration and intraluminal growth type. The primary end-point was the complete ER (ER0) rate, with a sample size of 42.

RESULTS

We enrolled 46 patients with 46 lesions between September 2020 and May 2023 at seven Japanese institutions. The mean ± SD (range) endoscopic tumor size was 18.8 ± 4.5 (11-28) mm. The tumor resection and defect closure times were 54 ± 26 (22-125) min and 33 ± 28 (12-186) min, respectively. A 100% ER0 was achieved in all 46 patients. The EFTR procedure was accomplished in all patients without surgical intervention. One patient had delayed perforation and was managed endoscopically. GIST accounted for 76% (n = 35) of the cases. R0, R1, and RX rates were 33 (77%), 3 (6.5%), and 7 (15%), respectively.

CONCLUSION

Endoscopic full-thickness resection for gastric SMT of 11-30 mm is efficacious. It warrants further validation in a large-scale cohort study to determine the long-term outcome of this treatment for patients with gastric GIST.

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.

Feasibility and efficacy of minimally invasive limited resection for primary duodenal gastrointestinal stromal tumors: a retrospective cohort study

BACKGROUND

The primary duodenal gastrointestinal stromal tumor (GIST) is a rare type of gastrointestinal tract tumor. Limited resection (LR) has been increasingly performed for duodenal GIST. However, only a few studies reported minimally invasive limited resection (MI-LR) for primary duodenal GIST.

METHODS

The clinical data of 33 patients with primary duodenal GIST from December 2014 to February 2024 were retrospectively analyzed including 23 who received MI-LR and 10 who received laparoscopic or robotic pancreaticoduodenectomy (LPD/RPD).

RESULTS

A total of 33 patients with primary duodenal GIST were enrolled and retrospectively reviewed. Patients received MI-LR exhibited less OT (280 vs. 388.5min, P=0.004), EBL (100 vs. 450ml, P<0.001), and lower morbidity of postoperative complications (52.2% vs. 100%, P=0.013) than LPD/RPD. Patients received LPD/RPD burdened more aggressive tumors with larger size (P=0.047), higher classification (P<0.001), and more mitotic count/50 HPF(P=0.005) compared with patients received MI-LR. The oncological outcomes were similar in MI-LR group and LPD/RPD group. All the patients underwent MI-LR with no conversion, including 12 cases of LLR and 11 cases of RLR. All of the clinicopathological data of the patients were similar in both groups. The median OT was 280(210-480) min and 257(180-450) min, and the median EBL was 100(20-1000) mL and 100(20-200) mL in the LLR and the RLR group separately. The postoperative complications mainly included DGE (LLR 4 cases, 33.4% and RLR 4 cases, 36.4%), intestinal fistula (LLR 2 cases, 16.7%, and RLR 0 case), gastrointestinal hemorrhage (LLR 0 case and RLR 1 case, 9.1%), and intra-abdominal infection (LLR 3 cases, 25.0% and RLR 1 case, 9.1%). The median postoperative length of hospitalization was 19.5(7-46) days in the LLR group and 19(9-38) days in the RLR group. No anastomotic stenosis, local recurrence or distant metastasis was observed during the follow-up period in the two groups.

CONCLUSIONS

Minimally invasive limited resection is an optional treatment for primary duodenal GIST with satisfactory short-term and long-term oncological outcomes.

The development of a prediction model based on deep learning for prognosis prediction of gastrointestinal stromal tumor: a SEER-based study

Accurately predicting the prognosis of Gastrointestinal stromal tumor (GIST) patients is an important task. The goal of this study was to create and assess models for GIST patients' survival patients using the Surveillance, Epidemiology, and End Results Program (SEER) database based on the three different deep learning models. Four thousand five hundred thirty-eight patients were enrolled in this study and divided into training and test cohorts with a 7:3 ratio; the training cohort was used to develop three different models, including Cox regression, RSF, and DeepSurv model. Test cohort was used to evaluate model performance using c-index, Brier scores, calibration, and the area under the curve (AUC). The net benefits at risk score stratification of GIST patients based on the optimal model was compared with the traditional AJCC staging system using decision curve analysis (DCA). The clinical usefulness of risk score stratification compared to AJCC tumor staging was further assessed using the Net Reclassification Index (NRI) and Integrated Discrimination Improvement (IDI). The DeepSurv model predicted cancer-specific survival (CSS) in GIST patients showed a higher c-index (0.825), lower Brier scores (0.142), and greater AUC of receiver operating characteristic (ROC) analysis (1-year ROC:0.898; 3-year:0.853, and 5-year ROC: 0.856). The calibration plots demonstrated good agreement between the DeepSurv model's forecast and actual results. The NRI values ( training cohort: 0.425 for 1-year, 0.329 for 3-year and 0.264 for 5-year CSS prediction; test cohort:0.552 for 1-year,0.309 for 3-year and 0.255 for 5-year CSS prediction) and IDI (training cohort: 0.130 for 1-year,0.141 for 5-year and 0.155 for 10-year CSS prediction; test cohort: 0.154 for 1-year,0.159 for 3-year and 0.159 for 5-year CSS prediction) indicated that the risk score stratification performed significantly better than the AJCC staging alone (P < 0.001). DCA demonstrated the risk score stratification as more clinically beneficial and discriminatory than AJCC staging. Finally, an interactive native web-based prediction tool was constructed for the survival prediction of GIST patients. This study established a high-performance prediction model for projecting GIST patients based on deep learning, which has advantages in predicting each person's prognosis and risk stratification.

Pimitespib for the treatment of advanced gastrointestinal stromal tumors and other tumors

Pimitespib (TAS-116) is the first heat shock protein 90 (HSP90) inhibitor approved in Japan, and it is indicated for the treatment of gastrointestinal stromal tumors (GIST) that have progressed after treatment with imatinib, sunitinib and regorafenib. This review describes the preclinical and clinical research with pimitespib, including its mechanism of action, pharmacokinetics, clinical antitumour activity and safety. In a phase III study, pimitespib significantly prolonged progression-free survival compared with placebo (median 2.8 vs 1.4 months; hazard ratio 0.51; 95% CI 0.30-0.87; p = 0.006). Common treatment-related adverse events were diarrhoea, decreased appetite, increase in serum creatinine, malaise, nausea and eye disorders. The efficacy and safety of pimitespib are being investigated in other tumour types and in combination with other anticancer therapies.

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

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

Genomic profiling in GIST: Implications in clinical outcome and future challenges

Gastrointestinal Stromal Tumors (GIST) are the most frequent mesenchymal neoplasia of the digestive tract. Genomic alterations in KIT, PDFGRA, SDH, and BRAF genes are essential in GIST oncogenesis. Therefore, the mutations in these genes have demonstrated clinical implications. Tumors with deletions in KIT-exon 11 or duplications in exon 9 are associated with a worse prognosis. In contrast, KIT-exon 11 substitutions and duplications are associated with a better clinical outcome. Moreover, mutations in Kit exon 9 and 11 are actionable, due to their response to imatinib, while mutations in PDGFRA respond to sunitinib and/or avapritinib. Although, molecular testing on tissue samples is effective; it is invasive, requires adequate amounts of tissue, and a long experimental process is needed for results. In contrast, liquid biopsy has been proposed as a simple and non-invasive method to test biomarkers in cancer. The most common molecule analyzed by liquid biopsy is circulating tumor DNA (ctDNA). GISTs ctDNA testing has been demonstrated to be effective in identifying known and novel KIT mutations that were not detected using traditional tissue DNA testing and have been useful in determining progression risk and response to TKI therapy. This allows the clinician to have an accurate picture of the genetic changes of the tumor over time. In this work, we aimed to discuss the implications of mutational testing in clinical outcomes, the methods to test ctDNA and the future challenges in the establishment of alternatives of personalized medicine.

Current challenges and practical aspects of molecular pathology for bone and soft tissue tumors

This review shows the extraordinary change molecular pathology has induced in the classification, diagnosis, and clinical practice of molecular pathologists dealing with sarcomas. We have primarily focused on the practical aspects of molecular studies and the current and mid-term challenges for our subspecialty, ending with ten tips for the next generation of sarcoma molecular pathologists.

Individualized Dosing Patterns in the Treatment of Older Patients with Gastrointestinal Stromal Tumors: Results of a Registry-Based Observational National Cohort Study Including 871 Patients

BACKGROUND

While the effectiveness of tyrosine kinase inhibitors (TKIs) seems similar in older patients with gastrointestinal stromal tumors (GIST) compared with younger patients, toxicities in older patients treated with TKIs more often lead to discontinuation of treatment.

OBJECTIVE

To better understand the age-related pharmacology and pharmacodynamic differences in patients with GIST treated with TKIs, the primary aim of this study was to evaluate TKI dosing patterns in older patients with GIST, while the secondary aims were to evaluate differences in imatinib trough plasma concentrations between age groups and to compare the overall survival (OS) in patients with and without dose reductions in all treatment lines in a palliative setting.

METHODS

Patients (18 years of age or older) with histologically proven GIST diagnosed between January 2009 and June 2021 and treated with one or more lines of TKIs were selected from the Dutch GIST Registry (DGR) database. Age groups were divided into younger patients (age <70 years) and older patients (age ≥70 years). All imatinib trough plasma concentrations of blood withdrawals taken from initiation of imatinib until a maximum of 1 year of treatment with imatinib were collected. Reasons for first adjustment of treatment were classified as adverse event, dose modification, progressive disease and other reasons. The next treatment steps after first adjustment of treatment were defined as dose escalation, dose reduction, dose interruption, or end of treatment. The association of dose reduction and OS was analyzed using the landmark approach.

RESULTS

Overall, 871 patients were included in this study, including 577 younger patients and 294 older patients. Older patients more often had an adverse event as the reason for first adjustment of treatment with both imatinib (45.6%; p < 0.001) and sunitinib (58.6%; p = 0.224) compared with younger patients (19.5% and 42.7%, respectively). Adjustment of imatinib and sunitinib after starting on a standard dose because of an adverse event most often resulted in dose reduction in both age groups. Median trough plasma concentrations of all samples taken within the first year after initiation of imatinib were higher in older patients (1228 ng/mL, interquartile range [IQR] 959-1687) compared with younger patients (1035 ng/mL [IQR 773-1377]; p < 0.001). No significant differences were seen between OS in patients with or without dose reduction in all treatment lines (imatinib: p = 0.270; sunitinib: p = 0.547; and regorafenib: p = 0.784).

CONCLUSION

Older patients showed higher imatinib trough plasma concentrations compared with younger patients and also had earlier and more often adverse events as the reason for first adjustment of treatment with imatinib followed by dose reduction. However, in a landmark analysis, patients with imatinib dose reductions had no poorer outcomes compared with patients not requiring a dose reduction.

Ultrasound findings and clinical characteristics in differentiating renal urothelial carcinoma from endophytic clear cell renal cell carcinoma

OBJECTIVE

This study aimed to evaluate the clinical characteristics and features of conventional ultrasound (CUS) and contrast-enhanced ultrasound (CEUS) in differentiating between renal urothelial carcinomas (RUC) and endophytic clear cell renal cell carcinomas (EccRCC).

METHODS

A total of 72 RUCs and 120 EccRCCs confirmed by pathology were assessed retrospectively. Both CUS and CEUS were performed within 4 weeks before the surgery. Logistic regression analyses were used to select statistically significant variables of clinical, CUS, and CEUS features for the differentiation of RUC and EccRCC. Sensitivity (SEN), specificity (SPE), and the area under the receiver-operating characteristic curve (AUC) were assessed for diagnostic performance. Inter- and intra-observer agreements of CUS and CEUS features were evaluated using the intra-class correlation coefficient(ICC).

RESULTS

Multiple logistic regression analysis demonstrated that clinical (age >50 years old and hematuria), CUS (size <4.0 cm, hypo-echogenicity, irregular shape, hydronephrosis) and CEUS (absence of non-enhancement area, iso- /hypo-enhancement in cortical phase and absence of rim-like enhancement) features were independent factors for RUC diagnosis. When combining clinical characters with CUS and CEUS features into an integrated diagnostic criterion, the AUC reached 0.917 (95% CI 0.873-0.961), with a sensitivity of 95.8% and specificity of 87.5%. ICC ranged from 0.756 to 0.907 for inter-observer agreement and 0.791 to 0.934 for intra-observer agreement for CUS and CEUSfeatures.

CONCLUSIONS

The combination of clinical features of age and hematuria with imaging features of CUS and CEUS can be useful for the differentiation between RUC and EccRCC.

A Unique Case of Mesenteric Gastrointestinal Stromal Tumor Presenting as an Acute Abdomen

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the digestive tract and arise from the interstitial cells of Cajal in the mesenteric plexus. These tumors can originate in any part of the GI tract; however, a higher burden has been observed in the stomach and small intestines. Mesenteric GISTs are exceedingly rare, with unique clinicopathological features and a poorer prognosis. Herein, we describe a unique case of a 66-year-old female with a remote history of appendectomy who presented to the emergency room complaining of severe abdominal pain and vomiting. On imaging, the patient was found to have a large inflammatory mass associated with small bowel loops, and the pathology confirmed a mesenteric GIST. The tumor was resected, and the genomic test results confirmed the KIT (exon 11) mutation. Although the tumor had a low mitotic rate, the tumor was large enough to warrant the initiation of adjuvant imatinib mesylate for 36 months with regular bloodwork and imaging.

Drugs in the GIST Field (Therapeutic Targets and Clinical Trial Staging)

BACKGROUND

Molecular targeted therapies are the most important type of medical treatment for GIST, but the development of GIST drugs and their targets have not been summarized.

METHODS

Drugs in the field of GIST were analyzed and collated through Pharmaprojects, ClinicalTrials. gov and PharmaGO databases.

RESULTS

As of 2021, there are 75 drugs that have appeared in the GIST clinical trials. The six most frequent targets in GIST clinical trials, in descending order of frequency, were KIT, PDGFRA, KDR (VEGFR2), FLT3, FLT1 (VEGFR1), and FLT4/VEGFR3. Only 8 drugs are in preclinical research. There are challenges in the development of new drugs for GIST.

CONCLUSION

This article analyzes and summarizes the general situation of GIST drugs, the target distribution of GIST drugs, and the trends in GIST drug-related clinical trials.

Assessing prognostic factors of long-term survival after surgery for colorectal gastrointestinal stromal tumours

AIM

Due to their rarity, the management of colorectal gastrointestinal stromal tumours (CR GISTs) is still under debate. The aim of this study was to assess prognostic factors.

METHOD

We performed a retrospective review of patients who underwent surgery with curative intent for CR GIST at our centre from 2002 to 2019. Factors associated with overall (OS) and recurrence-free survival (RFS) were analysed.

RESULTS

Fifty-six patients were included [median age 63 years, 29 (52%) female, 30 (54%) Miettinen high-risk, 40 (71%) with rectal GIST]. Nineteen (34%) patients received perioperative (neoadjuvant and/or adjuvant) imatinib. All cases of colonic GIST had an R0 resection, compared with 28 (70%) of rectal GISTs. After a median follow-up of 97 months (interquartile range 48-155 months), 14 (25%) deaths and 14 (25%) recurrences occurred. In the high-risk cohort, factors associated with improved RFS were R0 resection (OR 0.19, 95% CI 0.1-0.5, p = 0.002) and perioperative imatinib (OR 0.33, 95% CI 0.42-0.97, p = 0.04). Patients who had received perioperative imatinib had longer RFS (60% vs. 11% at 5 years, p = 0.006) but not OS. In rectal GISTs, 5-year OS was 85% for R0 and 70% for R1 resections (p = 0.164) and 5-year RFS was 85% for R0 and 12% for R1 resection (p < 0.001). When stratifying patients by perioperative imatinib, there were no differences in OS or RFS in the R0 or R1 groups.

CONCLUSION

Perioperative imatinib and R0 resection were associated with improved RFS in high-risk patients with CR GIST. In patients with rectal GIST, R1 resection was associated with worse RFS irrespective of perioperative imatinib treatment.

Hallmarks and novel insights for gastrointestinal stromal tumors: A bibliometric analysis

BACKGROUND

Due to the increasing recognition of gastrointestinal stromal tumor (GIST), novel insights have appeared in both preclinical and clinical research and begun to reshape the field. This study aims to map the research landscape through bibliometric analysis and provide a brief overview for the future of the GIST field.

METHODS

We searched the Web of Science Core Collection without publication data restrictions for GISTs and performed a bibliometric analysis with CiteSpace and VOSviewer software.

RESULTS

In sum, 5,911 of 13,776 records were included, and these studies were published in 948 journals and written by 24,965 authors from 4,633 institutions in 100 countries. Referring to published reviews and bibliometric analysis, we classified the future trends in four groups. In epidemiological study, precise incidence and clinicopathological features in different regions and races might become potential hotspots. Novel therapy, such as drugs, modified strategies, radioligand therapy, was persistent hotspots in GIST fields, and ctDNA-guided diagnosis, monitoring, and treatment might meet future clinical needs. The debate over serosa surgery vs. mucosa surgery will remain active for a long time in GIST surgery, and function reserve surgery, biology-based surgery will play an important role in future. Moreover, rare GIST type, like NF-1-associated GIST, Carney triads and SDH mutant GIST, need more studies in pathogenesis and genetic mutation to provide appropriate treatment for this orphan GIST patients.

CONCLUSIONS

Potential hotspots in future GIST trends might involve epidemiology, agents, resection therapy and rare type GIST, moreover, researchers could pay more attention in these four fields.

Neoadjuvant Imatinib in Locally Advanced Gastrointestinal Stromal Tumors (GISTs) is Effective and Safe: Results from a Prospective Single-Center Study with 108 Patients

BACKGROUND

Neoadjuvant imatinib is considered for gastrointestinal stromal tumors (GISTs) when decreased tumor size provides less extensive surgery and higher R0 resection rates. This study evaluates the effectivity and safety of neoadjuvant imatinib for large or locally advanced GIST.

PATIENTS AND METHODS

From the prospective database of the Dutch GIST Consortium, all patients who underwent surgery after neoadjuvant imatinib at our center between 2009 and 2022 were selected. Independent and blinded assessment of surgical strategy was performed by two surgeons, based on anonymized computed tomography (CT) scans before and after neoadjuvant imatinib.

RESULTS

Of 113 patients that received neoadjuvant imatinib, 108 (95%) [mean age 61.6, standard deviation (SD) 11.5, 54% male] underwent a GIST resection. Of all GISTs, 67% was localized in the stomach and 25% in the duodenum or small intestine. In 74% of the patients with GIST, a KIT exon 11 mutation was found. Decreased tumor size was seen in 95 (88%) patients. Having a KIT exon 11 mutation [odds ratio (OR) 5.64, 95% confidence interval (CI) 1.67-19.1, p < 0.01] or not having a mutation (OR 0.19, 95% CI 0.04-0.89, p = 0.04) were positive and negative predictive values for partial response, respectively. In 55 (51%) patients, there was deescalation of surgical strategy after neoadjuvant imatinib. Surgical complications were documented in 16 (15%) patients (n = 8, grade II; n = 5, grade IIIa; n = 3, grade IIIb) and R0 resection was accomplished in 95 (89%) patients. The 5-year disease-free and overall survival were 80% and 91%, respectively.

CONCLUSION

This study shows that neoadjuvant imatinib is effective and safe for patients with large or locally advanced GIST.

A gist on an obscure neoplasm in Ghana: gastrointestinal stromal tumours

BACKGROUND

Gastrointestinal Stromal Tumour is a rare but potentially curable tumour of the gastrointestinal tract accounting for up to 1% of all gastrointestinal tumours. The discovery of Imatinib mesylate, a novel tyrosine kinase inhibitor has improved the chances even for unresectable, recurrent, or metastatic diseases.

METHODS

This study sought to document the clinical and pathological characteristics of GISTs from two tertiary hospitals in Ghana that have undergone immunohistochemistry confirmation between 2014 and 2021.

RESULTS

The median age of the subjects was 50 years with most of them (28.0%) being above 61 years. There were more females than males (64.0% vs. 36.0%). Abdominal mass and abdominal pain made up the majority of the clinical presentations. The majority of the subjects had partial gastrectomy (32.0%) which was followed by wedge resection (28.0%). Appendectomy and sleeve gastrectomy were the least performed procedures (8% each). Four of the 25 patients (16.0%) had resections of involved contiguous organs done with splenectomy being the most common procedure. The majority of GISTs were found in the stomach (68.0%) followed by the appendix (12.0%) and small bowel (12.0%). Gastrointestinal bleeding (55.8%) and abdominal pain (38.5%) were the most reported symptoms. Free resection margins were observed in 84.0% of the subjects and only 3/25 (12.0%) experienced tumour recurrence.

CONCLUSION

GIST is a potentially curable tumour that once was obscure but currently gaining popularity. Surgical resection offers the hope of a cure for localized disease while targeted therapies is a viable option for recurrent, metastatic, or unresectable tumours.

Giant Exophytic Gastrointestinal Stromal Tumor (GIST) Arising From the Antral Stomach: A Surgical Case Report

This comprehensive case report meticulously outlines the clinical manifestation, diagnostic trajectory, surgical intervention, pathology, chemotherapy, and patient follow-up in a challenging instance of a giant exophytic gastrointestinal stromal tumor (GIST) emerging from the antral part of the stomach in a 56-year-old male patient. Over the course of a year, the patient presented with symptoms including abdominal distension, a progressively enlarging lump, constipation, and abdominal fullness. Our diagnostic strategy, anchored by ultrasonography and contrast-enhanced computed tomography (CECT), yielded crucial insights into the tumor's precise dimensions and anatomical location. The subsequent surgical planning and execution were pivotal, entailing a meticulous dissection of the cystic mass from adjacent structures to ensure negative margins. Histopathological scrutiny of frozen sections from the lymph nodes and excised antral margins conclusively confirmed the absence of malignancy, facilitating primary closure. This case report underscores the decisive role of accurate diagnostic imaging in shaping surgical strategies and emphasizes the need for a multidisciplinary approach to managing GISTs. Beyond the surgical realm, the case highlights the significance of tyrosine kinase inhibitors (TKIs), particularly imatinib, in the treatment paradigm. Additionally, the report sheds light on ongoing research endeavors to refine treatment modalities in GISTs.

Large-Scale, Multicenter, Prospective Registry Study of Ripretinib in Advanced GIST: A Real-World Study from China

INTRODUCTION

Tyrosine-kinase inhibitors (TKIs) have become the standard treatment for patients with advanced gastrointestinal stromal tumor (GIST); however, secondary mutations can still drive disease progression. Studies have shown that ripretinib, a novel switch-control TKI, inhibits various primary and secondary drug-resistant mutations. There is a paucity of data on the effectiveness and safety of ripretinib in a real-world setting. This prospective, large-scale, real-world registry study aimed to evaluate the effectiveness and safety of ripretinib as a fourth-line treatment in Chinese patients with advanced GIST.

METHODS

Patients ≥ 18 years of age having recurrent/metastatic GIST were enrolled. Key endpoints were median progression-free survival (mPFS), median overall survival (mOS), and adverse events (AEs) incidence. Univariate and multivariate analyses were conducted to identify various parameters associated with PFS.

RESULTS

A total of 240 patients were enrolled. After a median follow-up period of 6.5 months, the mPFS [95% confidence interval (CI)] was 7.70 (6.60, 8.60) months and the mOS was not reached. Multivariate analysis revealed association of Eastern Cooperative Oncology Group (ECOG) performance status score with PFS and superior benefits for non-gastric was observed as compared to gastric GISTs [hazard ratio (HR) 0.58, 95% CI (0.39-0.86)]. Disease control rate and tumor shrinkage (any magnitude) was 73% and 43%, respectively. Ripretinib was also effective in the subgroup of patients with different gene mutations. The toxicities were tolerable, and most reported AEs were alopecia (17.1%) and hand-foot syndrome (15.4%).

CONCLUSION

Ripretinib demonstrated effectiveness and a tolerable safety profile, making it a viable option as a fourth- or later-line treatment in Chinese patients with advanced GISTs, especially for non-gastric GISTs.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT05697107.

Goldilocks principle of minimally invasive surgery for gastric subepithelial tumors

BACKGROUND

Minimally invasive surgery had been tailored to individual cases of gastric subepithelial tumors (SETs) after comparing the clinical outcomes of endoscopic resection (ER), laparoscopic resection (LR), and hybrid methods.

AIM

To study the use of Goldilocks principle to determine the best form of minimally invasive surgery for gastric SETs.

METHODS

In this retrospective study, 194 patients of gastric SETs with high probability of surgical intervention were included. All patients underwent tumor resection in the operating theater between January 2013 and December 2021. The patients were divided into two groups, ER or LR, according to the tumor characteristics and the initial intent of intervention. Few patients in the ER group required further backup laparoscopic surgery after an incomplete ER. The patients who had converted open surgery were excluded. A logistic regression model was used to assess the associations between patient characteristics and the likelihood of a treatment strategy. The area under the curve was used to assess the discriminative ability of tumor size and Youden's index to determine the optimal cut-off tumor size.

RESULTS

One-hundred ninety-four patients (100 in the ER group and 94 in the LR group) underwent tumor resection in the operating theater. In the ER group, 27 patients required backup laparoscopic surgery after an incomplete ER. The patients in the ER group had small tumor sizes and shorter procedure durations while the patients in the LR group had large tumor sizes, exophytic growth, malignancy, and tumors that were more often located in the middle or lower third of the stomach. Both groups had similar durations of hospital stays and a similar rate of major postoperative complications. The patients in the ER group who underwent backup surgery required longer procedures (56.4 min) and prolonged stays (2 d) compared to the patients in the LR group without the increased rate of major postoperative complications. The optimal cut-off point for the tumor size for laparoscopic surgery was 2.15 cm.

CONCLUSION

Multidisciplinary teamwork leads to the adoption of different strategies to yield efficient clinical outcomes according to the tumor characteristics.

Gastrointestinal Stromal Tumors: Our Ten-Year Experience of a Single-Center Tertiary Hospital

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal neoplasms of the gastrointestinal tract. They have variable clinical presentation, prognosis, and molecular characteristics. Here, we present the results of our retrospective study including patients operated on for GIST during the last decade.

METHODS

All the patients who underwent GIST resection during the decade 2008-2018 were included in the study. The diagnosis was based on the pathology report. All the data were collected and analyzed statistically using the Statistical Package for Social Science v25.0. Finally, after having applied the proper search terms, a comprehensive review of articles published in the Medline database was held.

RESULTS

Thirty-two patients (sixteen women) were included in the study with a mean age of 69.6 years old (SD = 13.9). Twenty-one patients had a GIST in the stomach, eight in the small intestine, and three had an extra GIST. Of the 29 patients contacted, 21 were alive with a mean survival time of 74.3 months (SD = 49.6 months, min: 3.0 months, max: 161.0 months), whereas eight patients passed away. Finally, 13 patients were treated with tyrosine kinase inhibitors (TKIs) of whom only one died, while 9 patients passed away from those treated with surgery alone (p = 0.031).

CONCLUSIONS

Our results were in concordance with the existing data in the literature. GISTs require patient-based therapeutical management depending on the histology of the tumors. Gastric tumors present a better prognosis than those localized in the intestine, while the use of TKIs has led to an improvement in patient survival rate.

Development and validation of a prognostic nomogram for gastrointestinal stromal tumors in the postimatinib era: A study based on the SEER database and a Chinese cohort

BACKGROUND

After the standardization, recording and follow-up of imatinib use that significantly prolongs survival of gastrointestinal stromal tumors (GISTs), a comprehensive reassessment of the prognosis of GISTs is necessary and more conductive to treatment options.

METHODS

A total of 2185 GISTs between 2013 and 2016 were obtained from the Surveillance, Epidemiology, and End Results database and comprised our training (n = 1456) and internal validation cohorts (n = 729). The risk factors extracted from univariate and multivariate analyses were used to establish a predictive nomogram. The model was evaluated and tested in the validation cohort internally and in 159 patients with GIST diagnosed between January 2015 and June 2017 in Xijing Hospital externally.

RESULTS

The median OS was 49 months (range, 0-83 months) in the training cohort and 51 months (0-83 months) in the validation cohort. The concordance index (C-index) of the nomogram was 0.777 (95% CI, 0.752-0.802) and 0.7787 (0.7785, bootstrap corrected) in training and internal validation cohorts, respectively, and 0.7613 (0.7579, bootstrap corrected) in the external validation cohort. Receiver operating characteristic curves and calibration curves for 1-, 3-, and 5-year overall survival (OS) showed a high degree of discrimination and calibration. The area under the curve showed that the new model performed better than the TNM staging system. In addition, the model could be dynamically visualized on a webpage.

CONCLUSION

We developed a comprehensive survival prediction model for assessing the 1-, 3- and 5-year OS of patients with GIST in the postimatinib era. This predictive model outperforms the traditional TNM staging system and sheds light on the improvement of the prognostic prediction and the selection of treatment strategies for GISTs.

Antitumor Efficacy of the Novel KIT Inhibitor IDRX-42 (Formerly M4205) in Patient- and Cell Line-Derived Xenograft Models of Gastrointestinal Stromal Tumor (GIST)

PURPOSE

The majority of gastrointestinal stromal tumors (GIST) are driven by constitutively activated KIT/PDGFRA kinases and are susceptible to treatment with tyrosine kinase inhibitors. During treatment, most of these tumors will develop secondary mutations in KIT or PDGFRA inducing drug resistance, so there is an unmet need for novel therapies. We tested the efficacy of IDRX-42, a novel selective KIT inhibitor with high activity toward the most relevant KIT mutations, in 4 GIST xenograft models.

EXPERIMENTAL DESIGN

NMRI nu/nu mice were transplanted with patient-derived GIST xenograft models UZLX-GIST9 (KIT:p.P577del;W557LfsX5;D820G), UZLX-GIST2B (KIT:p.A502_Y503dup), UZLX-GIST25 (KIT:p.K642E), and the cell line-derived model GIST882 (KIT:p.K642E). Mice were treated daily with vehicle (control), imatinib (100 mg/kg), sunitinib (20 mg/kg), avapritinib (5 mg/kg), or IDRX-42 (10 mg/kg, 25 mg/kg). Efficacy was assessed by tumor volume evolution, histopathology, grading of histologic response, and IHC. The Kruskal-Wallis and Wilcoxon matched-pairs tests were used for statistical analysis, with P < 0.05 considered as significant.

RESULTS

IDRX-42 (25 mg/kg) caused tumor volume shrinkage in UZLX-GIST25, GIST882, and UZLX-GIST2B, with a relative decrease to 45.6%, 57.3%, and 35.1% on the last day as compared with baseline, and tumor growth delay (160.9%) compared with control in UZLX-GIST9. Compared with controls, IDRX-42 (25 mg/kg) induced a significant decrease in mitosis. In UZLX-GIST25 and GIST882 grade 2-4 histologic response with myxoid degeneration was observed in all IDRX-42 (25 mg/kg)-treated tumors.

CONCLUSIONS

IDRX-42 showed significant antitumor activity in patient- and cell line-derived GIST xenograft models. The novel kinase inhibitor induced volumetric responses, decreased mitotic activity, and had antiproliferative effects. In models with KIT exon 13 mutation IDRX-42 induced characteristic myxoid degeneration.

Surgical Management of Germline Gastrointestinal Stromal Tumor

Gastrointestinal stromal tumor (GIST) is the most common human sarcoma and usually results from a sporadic mutation in KIT or, less frequently, platelet-derived growth factor alpha (PDGFRA). Rarely, a germline mutation in the KIT, PDGFRA, succinate dehydrogenase (SDH), or neurofibromatosis 1 (NF1) gene is responsible for GIST. These tumors are found in the stomach (PDGFRA and SDH), small bowel (NF1), or a combination of both (KIT). There is a need to improve care for these patients regarding genetic testing, screening, and surveillance. Since most GISTs due to a germline mutation do not respond to tyrosine kinase inhibitors, the role of surgery is critical, especially when considering germline gastric GIST. However, in contrast to the established recommendation for prophylactic total gastrectomy in cadherin 1 (CDH1) mutation carriers once they reach adulthood, there are no formal guidelines as to the timing or extent of surgical resection for patients who are either carriers of a germline GIST mutation causing gastric GIST or have already developed gastric GIST(s). Surgeons must balance treating what is often multicentric, yet initially indolent disease with the chance of cure and the complications associated with total gastrectomy. Here, we consider the major issues in performing surgery in patients with germline GIST and illustrate the principles with a previously unreported patient harboring a germline KIT 579 deletion.

No-touch endoscopic full-thickness resection technique for gastric gastrointestinal stromal tumors

BACKGROUND : There remain concerns regarding the technical feasibility of endoscopic resection for large gastrointestinal stromal tumors (GISTs), mainly relating to the risk of tumor rupture and the adequacy of the resection margins. This study aimed to evaluate the feasibility and therapeutic outcomes of the newly developed no-touch endoscopic full-thickness resection (NT-EFTR) technique for GISTs. METHODS : In this retrospective study, 92 patients with gastric GISTs undergoing NT-EFTR were included. Clinicopathological, endoscopic, and follow-up data were collected and analyzed. RESULTS : The median tumor size was 2.5 cm and en bloc resection was achieved in all patients with negative surgical margins. The median time of the NT-EFTR procedure was 59.5 minutes. Large tumors (> 3.0 cm), extraluminal tumor growth pattern, and large gastric defects were significant contributors to long operative times. Patients were discharged within 4 days postoperatively. During follow-up, all patients were free from local recurrence and distant metastasis. CONCLUSIONS : NT-EFTR was a feasible method for the resection of gastric GISTs and can be expected to achieve complete radical resection. Large tumors with extraluminal growth and large gastric defects impact procedural difficulty.

Minimally invasive technique for gastric GIST at challenging locations: single incision surgical gastroscopy

Organ sparing resection of gastrointestinal stromal tumors (GISTs) located in the proximal stomach or esophagogastric junction can be challenging, resulting in proximal or total gastrectomy to facilitate a radical resection without tumor spill. We developed and evaluated a single incision surgical gastroscopy (SISG) procedure to provide a technically feasible alternative for the removal of gastric GISTs at these challenging locations. We developed an endoluminal resection of gastric GISTs through a small single abdominal incision and longitudinal ventral gastrotomy. Patients with a proximal tumor location, in whom a wedge resection was deemed challenging on pre-operative investigation were included in the current series. Safety, short-term oncological and surgical outcome were evaluated. We performed SISG in six consecutive patients with histopathological proven or suspected gastric GIST. In all patients, the procedure was performed successfully with no tumor rupture. The mean operative time was 61 min and there were no significant complications. Pathological examination showed a microscopically radical resection in all patients. Single incision surgical gastroscopy is a feasible technique with excellent short-term oncological and surgical outcomes. This technique serves as a good alternative for complicated resections for gastric GISTs at challenging locations.

Efficacy of post-first-line agents for advanced gastrointestinal stromal tumors following imatinib failure: A network meta-analysis

BACKGROUND

Imatinib is the standard first-line treatment for advanced gastrointestinal stromal tumors (GISTs); however, most patients eventually develop imatinib resistance, leading to considerable clinical challenges. Few direct comparisons have been made between different post-first-line therapies on clinical efficacy in advanced GIST following imatinib failure.

METHODS

Databases including PubMed, Embase, Scopus, Google Scholars, and Cochrane Library from inception to February 2023 were retrieved for randomized controlled trials evaluating the clinical efficacy of different post-first-line agents for advanced GIST following imatinib failure. Network and conventional meta-analysis were carried out using Stata/MP 16.0.

RESULTS

Ripretinib showed significant improvement in progression-free survival (PFS) rates from the 2nd to the 12th month compared to placebo, while there was virtually no evidence that the rest active agents had a significant benefit at the 12th month. Masitinib, ripretinib, sunitinib, regorafenib, and pimitespib exhibited significantly longer median PFS than placebo, and pairwise comparisons indicated there were no significant differences among masitinib, ripretinib, and sunitinib. These post-first-line agents decreased the risk of disease progression or death by 65% (HR = 0.35, 95% CI: 0.26-0.47) compared to placebo. Ripretinib and sunitinib came into effect earlier and exhibited more consistent overall survival (OS) rate improvements than masitinib and pimitespib, while pairwise comparisons revealed no significant differences in these four active agents concerning the improvement in OS rate. These post-first-line agents decreased the risk of death by 39% (HR = 0.61, 95% CI: 0.44-0.83) over placebo for advanced GIST following imatinib failure.

CONCLUSION

The active agents in our analysis as post-first-line therapies are able to provide superior clinical efficacy, with improved PFS rate and OS rate at certain time points, as well as absolute values of PFS and OS for advanced GIST. Ripretinib might be the optimal recommendation as a post-first-line treatment for advanced GIST following imatinib failure.

Incidence Trends and Main Features of Gastro-Intestinal Stromal Tumours in a Mediterranean Region: A Population-Based Study

Gastro-Intestinal Stromal Tumours (GISTs) are a kind of neoplasm whose diagnosis in common clinical practice just started in the current century, implying difficulties for proper registration. Staff from the Cancer Registry of Murcia, in southeastern Spain, were commissioned by the EU Joint Action on Rare Cancers into a pilot study addressing GIST registration that also yielded a population-based depiction of GISTs in the region, including survival figures. We examined reports from 2001 to 2015 from hospitals as well as cases already present in the registry. The variables collected were sex, date of diagnosis, age, vital status, primary location, presence of metastases, and risk level according to Joensuu's Classification. In total, 171 cases were found, 54.4% occurred in males, and the mean age value was 65.0 years. The most affected organ was the stomach, with 52.6% of cases. Risk level was determined as "High" for 45.0%, with an increment of lower levels in recent years. Incidence for the year 2015 doubled that of 2001. Overall, the 5-year net survival estimation was 77.0%. The rising incidence magnitude is consistent with trends in other European countries. Survival evolution lacked statistical significance. A more interventional approach in clinical management could explain the increase in the proportion of "Low Risk GISTs" and the first occurrence of "Very Low Risk" in recent years.

Role and mechanistic actions of protein kinase inhibitors as an effective drug target for cancer and COVID

Kinases can be grouped into 20 families which play a vital role as a regulator of neoplasia, metastasis, and cytokine suppression. Human genome sequencing has discovered more than 500 kinases. Mutations of the kinase itself or the pathway regulated by kinases leads to the progression of diseases such as Alzheimer's, viral infections, and cancers. Cancer chemotherapy has made significant leaps in recent years. The utilization of chemotherapeutic agents for treating cancers has become difficult due to their unpredictable nature and their toxicity toward the host cells. Therefore, targeted therapy as a therapeutic option against cancer-specific cells and toward the signaling pathways is a valuable avenue of research. SARS-CoV-2 is a member of the Betacoronavirus genus that is responsible for causing the COVID pandemic. Kinase family provides a valuable source of biological targets against cancers and for recent COVID infections. Kinases such as tyrosine kinases, Rho kinase, Bruton tyrosine kinase, ABL kinases, and NAK kinases play an important role in the modulation of signaling pathways involved in both cancers and viral infections such as COVID. These kinase inhibitors consist of multiple protein targets such as the viral replication machinery and specific molecules targeting signaling pathways for cancer. Thus, kinase inhibitors can be used for their anti-inflammatory, anti-fibrotic activity along with cytokine suppression in cases of COVID. The main goal of this review is to focus on the pharmacology of kinase inhibitors for cancer and COVID, as well as ideas for future development.

Current status of and future prospects for the treatment of unresectable or metastatic gastrointestinal stromal tumours

Gastrointestinal stromal tumours (GISTs) are soft-tissue sarcomas of the gastrointestinal tract. Surgery is the standard treatment for localised disease, but the risk of relapse and progression to more advanced disease is substantial. Following the discovery of the molecular mechanisms underlying GISTs, targeted therapies for advanced GIST were developed, with the first being the tyrosine kinase inhibitor (TKI) imatinib. Imatinib is recommended in international guidelines as first-line therapy to reduce the risk of GIST relapse in high-risk patients, and for locally advanced, inoperable and metastatic disease. Unfortunately, imatinib resistance frequently occurs and, therefore, second-line (sunitinib) and third-line (regorafenib) TKIs have been developed. Treatment options are limited for patients with GIST that has progressed despite these therapies. A number of other TKIs for advanced/metastatic GIST have been approved in some countries. Ripretinib is approved as fourth-line treatment of GIST and avapritinib is approved for GIST harbouring specific genetic mutations, while larotrectinib and entrectinib are approved for solid tumours (including GIST) with specific genetic mutations. In Japan, pimitespib, a heat shock protein 90 (HSP90) inhibitor, is now available as a fourth-line therapy for GIST. Clinical studies of pimitespib have indicated that it has good efficacy and tolerability, importantly not displaying the ocular toxicity of previously developed HSP90 inhibitors. Additional approaches for advanced GIST have been investigated, including alternative uses of currently available TKIs (such as combination therapy), novel TKIs, antibody-drug conjugates, and immunotherapies. Given the poor prognosis of advanced GIST, the development of new therapies remains an important goal.