Population-Based Epidemiology and Mortality of Small Malignant Gastrointestinal Stromal Tumors in the USA

Patterns of Care and Outcomes of Patients with Small Gastrointestinal Stromal Tumors at a High-Volume Sarcoma Center

BACKGROUND

The course of subclinical gastrointestinal stromal tumors (GISTs) is variable. The management of small GISTs is not well-defined.

METHODS

Records of patients presenting with small GISTs with documented follow-up appointment at our institution between 2016 and 2022 were identified and reviewed. Comparative univariate analysis to compare patient and tumor characteristics and outcomes was performed.

RESULTS

Eighty-six patients were followed for a median of 3.7 years (range 0.1-20 years). The median size at presentation was 1.7 (range 0.1-2.5) cm. A total of 51.2% (n = 44) underwent surgery before or immediately after initial presentation for pain (18.2%), bleeding (15.9%), or patient preference (6.8%). Another 17.4% (n = 15) had delayed surgery for tumor growth (40%), patient preference (2.7%), bleeding (6.7%), or pain (6.7%). The remaining 31.4% (n = 27) of patients never underwent surgery for reasons that included no growth/stability (44.4%), concomitant cancer diagnosis/treatment (29.6%), comorbidities (14.8%), and patient preference (3.7%). Patients who underwent surveillance without intervention compared with those who had delayed surgery were older (71.1 vs. 60.8 years, p < 0.001) with multiple comorbidities or a concurrent cancer diagnosis (70.3% vs. 20%, p = 0.005). There were no differences in survival or rate of distant metastases. Average time to surgery in the delayed group was 2 (range 0.1-10.3) years, and 86% of these patients underwent surgery by 5.5 years after diagnosis.

CONCLUSIONS

In older patients with comorbidities or concurrent cancer diagnoses, opting out of surgery does not affect survival. Conversely, younger patients, free from significant comorbidities or other diagnoses, may consider surgery or active surveillance for up to 5 years, with comparable outcomes.

The INSIGHT study: a randomized, Phase III study of ripretinib versus sunitinib for advanced gastrointestinal stromal tumor with KIT exon 11 + 17/18 mutations

Somatic KIT activating mutations drive most gastrointestinal stromal tumors (GISTs). Disease progression eventually develops with first-line imatinib, commonly due to KIT secondary mutations, and different kinase inhibitors have various levels of treatment efficacy dependent on specific acquired resistance mutations. Ripretinib is a broad-spectrum switch-control KIT/PDGFRA tyrosine kinase inhibitor for patients with advanced GIST who received prior treatment with three or more kinase inhibitors, including imatinib. Exploratory baseline circulating tumor DNA analysis from the second-line INTRIGUE trial determined that patients with advanced GIST previously treated with imatinib harboring primary KIT exon 11 mutations and secondary resistance mutations restricted to KIT exons 17/18 had greater clinical benefit with ripretinib versus sunitinib. We describe the rationale and design of INSIGHT (NCT05734105), an ongoing Phase III open-label study of ripretinib versus sunitinib in patients with advanced GIST previously treated with imatinib exclusively harboring KIT exon 11 + 17/18 mutations detected by circulating tumor DNA.Clinical Trial Registration: NCT05734105 (ClinicalTrials.gov).

A population-based study on incidence trends of small intestine cancer in the United States from 2000 to 2020

BACKGROUND

Although rare, small intestine cancer is on the rise in the developed world. We aimed to investigate the incidence trends of small intestine cancer by sex, race/ethnicity, age, and histological subgroups in the United States (US) over 2000-2020. Also, we evaluated the COVID-19 impacts on the incidence trends of this cancer.

METHODS

Data were collected from the Surveillance, Epidemiology, and End Results 22 database. Both the average annual percent change (AAPC) and age-standardized incidence rates (ASIRs) were determined. The findings were expressed as counts and incidence rates adjusted for age per 100,000 people with 95% confidence intervals (CIs).

RESULTS

A total of 67,815 cases of small intestine cancer across all age groups were reported in the US between 2000 and 2019. Neuroendocrine carcinoma was the most often reported subtype (54.26%). The age group of 55 to 69 years (38.08%), men (53.10%), and Non-Hispanic Whites (69.07%) accounted for the majority of cases. Over 2000-2019, the ASIRs for small intestine cancer among men and women were 2.61 (95% CI: 2.59-2.64) and 1.92 (95% CI: 1.89-1.94) per 100,000, indicating a significant increase of 2.01% and 2.12%, respectively. Non-Hispanic Black men had the highest ASIR (4.25 per 100,000). Also, those aged 80-84 age group had the highest ASIR. During COVID-19, the ASIR of small intestine cancer decreased by 8.94% (5.06-12.81%).

CONCLUSIONS

Small intestine cancer incidence raised in all sexes and ethnicities. Following COVID-19, reported cases declined, possibly due to pandemic-related diagnostic challenges. The impact of underdiagnosis on patient survival needs further investigations.

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.

Clinical course of small gastric subepithelial lesion less than 20 mm diagnosed by endoscopic ultrasound-guided fine-needle aspiration

BACKGROUND AND AIM

Gastrointestinal stromal tumors (GISTs) are treated as malignant gastric subepithelial lesions (SELs), and resection is recommended. However, small gastric SELs < 20 mm with no malignant features are monitored without histopathological examination, and the frequency of malignancy is unknown. This study aimed to clarify the clinicopathological findings and clinical course of gastric SELs < 20 mm measured by endoscopic ultrasound (EUS).

METHODS

This retrospective cohort study included consecutive patients with small gastric SELs < 20 mm diagnosed using EUS at a tertiary referral center between 2009 and 2021. The clinical course after diagnosis using EUS-guided fine-needle aspiration (EUS-FNA) was reviewed.

RESULTS

Among 333 patients with small gastric SELs, 104 patients with 105 lesions underwent EUS-FNA. The pathological diagnosis was confirmed in 87 patients. GISTs were the most common pathology (47%). Among the 87 patients, 43 underwent therapeutic interventions, including tumor resection and chemotherapy. In groups of tumor resection, the pathological tumor size on the resected specimen was significantly larger than the size measured by EUS (19.5 mm vs 15.0 mm, P < 0.001), and 37% of resected SELs were 20 mm or over. No recurrence was observed after tumor resection during a mean follow-up period of 40 months.

CONCLUSIONS

Approximately 40% of small gastric SELs were malignant tumors, such as GIST, with most of them requiring treatment. Additionally, considering that the EUS measurement is 5 mm smaller than the pathological tumor diameter, further examinations, such as systematic EUS-FNA, may be required for SEL, including those smaller than 20 mm.

The impact of gender on survival outcomes in patients with small intestinal stromal tumors: a comprehensive analysis using the SEER database

BACKGROUND

Small intestinal stromal tumors (SISTs) are a rare type of mesenchymal tumor. Gender is known to influence the incidence and prognosis of various tumors, but its role on the survival of SISTs at the population level remains unclear. Therefore, we aim to explore the relationship between gender and the prognosis of SISTs using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Data on SISTs patients from 2000 to 2019 were derived from the SEER database. Multiple imputation was used to address missing data. Kaplan-Meier analyses and Cox proportional hazard models were applied to evaluate the impact of demographic and clinical characteristics on overall survival (OS) and cancer-specific survival (CSS).

RESULTS

A total of 3513 patients with SISTs were analyzed, including 1921 males and 1592 females. Kaplan-Meier analysis coupled with log-rank testing demonstrated a significantly higher mortality rate among male patients compared to females (P < 0.001). Notably, female patients exhibited superior OS (hazard ratio [HR] 0.808, 95% confidence interval [CI] 0.724-0.902, P < 0.001) and CSS (HR 0.801, 95% CI 0.692-0.927, P = 0.003) compared to male patients. While the mean 1-year CSS rates were comparable between genders (95.3% for males vs. 96.0% for females, P = 0.332), male patients consistently showed lower mean survival rates at 3-, 5-, and 10-year intervals. Surgical intervention significantly boosted 5-year OS and CSS rates in both male and female patients (P < 0.001). Multivariate Cox regression analysis identified age, sex, grade, TNM stage, surgery, and mitotic rate as independent risk factors for OS and CSS in patients with SISTs.

CONCLUSIONS

Our findings suggest that male patients with SISTs have a higher risk of mortality compared to female patients, indicating that gender may serve as a predictive indicator for survival in this patient population.

Addressing the Gap: Racial Disparities and Public Health Strategies in the Epidemiology of Gastrointestinal Stromal Tumors

Background Gastrointestinal stromal tumors (GISTs) represent the most common mesenchymal neoplasms of the gastrointestinal tract, arising from the interstitial cells of Cajal. These tumors bridge the nervous system and muscular layers of the gastrointestinal tract, playing a crucial role in the digestive process. The incidence of GISTs demonstrates notable variations across different racial and ethnic groups, underscoring the need for in-depth analysis to understand the interplay of genetic, environmental, and socioeconomic factors behind these disparities. Linear regression analysis is a pivotal statistical tool in such epidemiological studies, offering insights into the temporal dynamics of disease incidence and the impact of public health interventions. Methodology This investigation employed a detailed dataset from 2009 to 2020, documenting GIST incidences across Asian, African American, Hispanic, and White populations. A meticulous preprocessing routine prepared the dataset for analysis, which involved data cleaning, normalization of racial terminologies, and aggregation by year and race. Linear regression models and Pearson correlation coefficients were applied to analyze trends and correlations in GIST incidences across the different racial groups, emphasizing an understanding of temporal patterns and racial disparities in disease incidence. Results The study analyzed GIST cases among four racial groups, revealing a male predominance (53.19%) and an even distribution of cases across racial categories: Whites (27.66%), Hispanics (25.53%), African Americans (24.47%), and Asians (22.34%). Hypertension was the most common comorbidity (32.98%), followed by heart failure (28.72%). The linear regression analysis for Asians showed a decreasing trend in GIST incidences with a slope of -0.576, an R-squared value of 0.717, and a non-significant p-value of 0.153. A significant increasing trend was observed for Whites, with a slope of 0.581, an R-squared value of 0.971, and a p-value of 0.002. African Americans exhibited a moderate positive slope of 0.277 with an R-squared value of 0.470 and a p-value of 0.201, indicating a non-significant increase. Hispanics showed negligible change over time with a slope of -0.095, an R-squared value of 0.009, and a p-value of 0.879, suggesting no significant trend. Conclusions This study examines GIST incidences across racial groups, revealing significant disparities. Whites show an increasing trend (p = 0.002), while Asians display a decreasing trend (p = 0.153), with stable rates in African Americans and Hispanics. Such disparities suggest a complex interplay of genetics, environment, and socioeconomic factors, highlighting the need for targeted research and interventions that address these differences and the systemic inequalities influencing GIST outcomes.

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.

A nomogram for predicting survival in patients with gastrointestinal stromal tumor: a study based on the surveillance, epidemiology, and end results database

Purpose

The objective of this investigation was to construct and validate a nomogram for prognosticating cancer-specific survival (CSS) in patients afflicted with gastrointestinal stromal tumor (GIST) at 3-, 5-, and 8-years post-diagnosis.

Methods

Data pertaining to patients diagnosed with GIST were acquired from the Surveillance, Epidemiology, and End Results (SEER) database. Through random selection, a training cohort (70%) and a validation cohort (30%) were established from the patient population. Employing a backward stepwise Cox regression model, independent prognostic factors were identified. Subsequently, these factors were incorporated into the nomogram to forecast CSS rates at 3-, 5-, and 8-years following diagnosis. The nomogram's performance was assessed using indicators such as the consistency index (C-index), the area under the time-dependent receiver operating characteristic curve (AUC), the net reclassification improvement (NRI), the integrated discrimination improvement (IDI), calibration curves, and decision-curve analysis (DCA).

Results

This investigation encompassed a cohort of 3,062 GIST patients. By analyzing the Cox regression model within the training cohort, nine prognostic factors were identified: age, sex, race, marital status, AJCC (American Joint Committee on Cancer) stage, surgical status, chemotherapy status, radiation status, and income status. The nomogram was subsequently developed and subjected to both internal and external validation. The nomogram exhibited favorable discrimination abilities, as evidenced by notably high C-indices and AUC values. Calibration curves confirmed the nomogram's reliability. Moreover, the nomogram outperformed the AJCC model, as demonstrated by enhanced NRI and IDI values. The DCA curves validated the clinical utility of the nomogram.

Conclusion

The present study has successfully constructed and validated the initial nomogram for predicting prognosis in GIST patients. The nomogram's performance and practicality suggest its potential utility in clinical settings. Nevertheless, further external validation is warranted.

A nomogram for predicting liver metastasis in patients with gastric gastrointestinal stromal tumor

BACKGROUND

Liver metastasis (LIM) is an important factor in the diagnosis, treatment, follow-up, and prognosis of patients with gastric gastrointestinal stromal tumor (GIST). There is no simple tool to assess the risk of LIM in patients with gastric GIST. Our aim was to develop and validate a nomogram to identify patients with gastric GIST at high risk of LIM.

METHODS

Patient data diagnosed as having gastric GIST between 2010 and 2019 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database and randomly divided into training cohort and internal validation cohort in a 7:3 ratio. For external validation, retrospective data collection was performed on patients diagnosed as having gastric GIST at Yunnan Cancer Center (YNCC) between January 2015 and May 2023. Univariate and multivariate logistic regression analyses were used to identify independent risk factors associated with LIM in patients with gastric GIST. An individualized LIM nomogram specific for gastric GIST was formulated based on the multivariate logistic model; its discriminative performance, calibration, and clinical utility were evaluated.

RESULTS

In the SEER database, a cohort of 2341 patients with gastric GIST was analyzed, of which 173 cases (7.39%) were found to have LIM; 239 patients with gastric GIST from the YNCC database were included, of which 25 (10.46%) had LIM. Multivariate analysis showed tumor size, tumor site, and sex were independent risk factors for LIM (P < .05). The nomogram based on the basic clinical characteristics of tumor size, tumor site, sex, and age demonstrated significant discrimination, with an area under the curve of 0.753 (95% CI, 0.692-0.814) and 0.836 (95% CI, 0.743-0.930) in the internal and external validation cohort, respectively. The Hosmer-Lemeshow test showed that the nomogram was well calibrated, whereas the decision curve analysis and the clinical impact plot demonstrated its clinical utility.

CONCLUSION

Tumor size, tumor subsite, and sex were significantly correlated with the risk of LIM in gastric GIST. The nomogram for patients with GIST can effectively predict the individualized risk of LIM and contribute to the planning and decision making related to metastasis management in clinical practice.

Precutting Endoscopic Band Ligation-Assisted Resection Is Safe and Effective for Treating Gastric Submucosal Tumors from the Muscularis Propria

BACKGROUND

We previously treated small gastric submucosal tumors originating from the muscularis propria layer by precutting endoscopic band ligation but lacked precise pathological results. Then, precutting endoscopic band ligation was modified by additional snare resection after ligation to obtain tumor specimens, termed precutting endoscopic band ligation-assisted resection.

AIMS

In this study, we aimed to explore the safety, feasibility, and efficacy of precutting endoscopic band ligation-assisted resection.

METHODS

From 2021 to 2022, a total of 16 consecutive patients underwent precutting endoscopic band ligation-assisted resection to treat small gastric submucosal tumors originating from the muscularis propria. The clinical demography, perioperative data, and follow-up outcomes were retrospectively collected.

RESULTS

With a mean operative time of 21.3 min, all lesions were successfully and completely resected, and no severe adverse events or local recurrences occurred postoperatively. More importantly, en bloc and R0 resection were achieved in all 16 patients.

CONCLUSION

Precutting endoscopic band ligation-assisted resection is a safe, effective, and time-saving endoscopic technique for managing gastric small gastric submucosal tumors originating from the muscularis propria for both diagnosis and eradication.

Automatically optimized radiomics modeling system for small gastric submucosal tumor (<2 cm) discrimination based on EUS images

BACKGROUND AND AIMS

The clinical management of small gastric submucosal tumors (SMTs) (<2 cm) faces a non-negligible challenge because of the lack of guideline consensus and effective diagnostic tools. This article develops an automatically optimized radiomics modeling system (AORMS) based on EUS images to diagnose and evaluate SMTs.

METHODS

A total of 205 patients with EUS images of small gastric SMTs (<2 cm) were retrospectively enrolled in the development phase of AORMS for the diagnosis and the risk stratification of GI stromal tumor (GIST). A total of 178 patients with images from different centers were prospectively enrolled in the independent testing phase. The performance of AORMS was compared to that of endoscopists in the development set and evaluated in the independent testing set.

RESULTS

AORMS demonstrated an area under the curve (AUC) of 0.762 for the diagnosis of GIST and 0.734 for the risk stratification of GIST, respectively. In the independent testing set, AORMS achieved an AUC of 0.770 and 0.750 for the diagnosis and risk stratification of small GISTs, respectively. In comparison, the AUCs of 5 experienced endoscopists ranged from 0.501 to 0.608 for diagnosing GIST and from 0.562 to 0.748 for risk stratification. AORMS outperformed experienced endoscopists by more than 20% in diagnosing GIST.

CONCLUSIONS

AORMS implements automatic parameter selection, which enhances its robustness and clinical applicability. It has demonstrated good performance in the diagnosis and risk stratification of GISTs, which could aid endoscopists in the diagnosis of small gastric SMTs (<2 cm).

Nomogram to predict gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions: Clinical significance

Transoral endoscopic resections in treating upper gastrointestinal submucosal lesions have the advantages of maintaining the integrity of the gastrointestinal lumen, avoiding perforation and reducing gastrointestinal fistulae. They are becoming more widely used in clinical practice, but, they may also present a variety of complications. Gas-related complications are one of the most common, which can be left untreated if the symptoms are mild, but in severe cases, they can lead to rapid changes in the respiratory and circulatory systems in a short period, which can be life-threatening. Therefore, it is important to predict the occurrence of gas-related complications early and take preventive measures actively. Based on the authors' results in the prepublication of the article "Nomogram to predict gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions," and in conjunction with our evaluation and additions to the relevant content, radiographs may help screen patients at high risk for gas-related complications. Controlling blood glucose levels, shortening the duration of surgery, and choosing the most appropriate surgical resection may positively impact the prognosis of patients at high risk for gas-related complications during transoral endoscopic resection of upper gastrointestinal submucosal lesions.

Impact of Tumor Size and Management on Survival in Small Gastric Gastrointestinal Stromal Tumors

BACKGROUND

Society guidelines remain inconsistent on the role of endoscopic and radiographic surveillance as an alternative to surgical resection of small gastric gastrointestinal stromal tumors (GISTs). Herein, we aimed to assess survival among patients with gastric GISTs undergoing observation versus surgical resection, stratified by tumor size.

METHODS

The National Cancer Database (NCDB) was queried for gastric GISTs < 2 cm diagnosed from 2010-2017. Patients were stratified by management strategy-observation vs surgical resection. The primary outcome, overall survival (OS), was examined with Kaplan-Meier and multivariable Cox proportional hazard methods. Subgroup analyses were conducted on tumors < 1 cm and 1-2 cm in size.

RESULTS

Altogether, 1208 patients were identified: 439 (36.3%) undergoing observation and 769 (63.7%) receiving surgical resection. In the overall cohort, patients undergoing surgical resection demonstrated improved survival (93.6 vs. 88.8% 5-year OS, p=0.02). In multivariable analysis, upfront surgical resection was not associated with a reduction in mortality; however, there was a significant interaction with tumor size. For patients with tumors < 1 cm, there was no difference in survival based on management strategy. However, resection of tumors 1-2 cm was associated with improved survival relative to surveillance.

CONCLUSIONS

While surgical resection and surveillance were associated with similar survival for patients with gastric GISTs < 1 cm, this NCDB analysis suggests that patients with tumor size ≥ 1 cm may benefit from upfront surgical resection. Prospective studies comparing these two approaches and their impact on recurrence-free and disease-specific survival are needed to better align consensus guidelines and recommendations.

Update of epidemiology, survival and initial treatment in patients with gastrointestinal stromal tumour in the USA: a retrospective study based on SEER database

OBJECTIVES

An updated epidemiological analysis of gastrointestinal stromal tumour (GIST), the change of cancer-specific survival (CSS) and patterns of initial treatment are of interest.

DESIGN

A retrospective study using data from the Surveillance, Epidemiology and End Results (SEER) database.

SETTING AND PARTICIPANTS

A total of 5625 patients with GIST diagnosed between 2010 and 2019 were identified.

PRIMARY OUTCOME MEASURES

Age-standardised incidence rate (ASIR) and annual prevalence rate were calculated. SEER combined stage, period CSS rate and initial treatment were summarised. All the data were calculated by SEER*Stat software.

RESULTS

From 2010 to 2019, the ASIR of GIST increased from 0.79 to 1.02 per 100 000 person-years, with an increase of 2.4% annually. The increase was across age and sex subgroups. The prevalence trend was similar with the ASIR trend in each subgroup. The stage distributions were similar between different age groups, but varied among different primary tumour sites. More importantly, a stage shift from regional stage to localized stage at diagnosis was found, which may result in the improvement of CSS over years. Overall, the 5-year CSS rate of GIST was approximately 81.3%. Even for metastatic GIST, the rate exceeded 50%. Surgery was the most common treatment regimen for GIST, followed by surgery and systemic treatment. Whereas approximately 7.0% patients were undertreated, which was more pronounced among patients with distant and unknown stages.

CONCLUSIONS

The findings of this study suggest an improving early detection of GIST and an improving ability of accurate staging. Though most patients are effectively treated and perform good survivals, approximate 7.0% patients may be undertreated.

Small Gastric Stromal Tumors: An Underestimated Risk

BACKGROUND AND OBJECTIVES

Small gastrointestinal stromal tumors (GISTs) are defined as tumors less than 2 cm in diameter, which are often found incidentally during gastroscopy. There is controversy regarding the management of small GISTs, and a certain percentage of small GISTs become malignant during follow-up. Previous studies which used Sanger targeted sequencing have shown that the mutation rate of small GISTs is significantly lower than that of large tumors. The aim of this study was to investigate the overall mutational profile of small GISTs, including those of wild-type tumors, using whole-exome sequencing (WES) and Sanger sequencing.

METHODS

Thirty-six paired small GIST specimens, which were resected by endoscopy, were analyzed by WES. Somatic mutations identified by WES were confirmed by Sanger sequencing. Sanger sequencing was performed in an additional 38 small gastric stromal tumor samples for examining hotspot mutations in KIT, PDGFRA, and BRAF.

RESULTS

Somatic C-KIT/PDGFRA mutations accounted for 81% of the mutations, including three novel mutation sites in C-KIT at exon 11, across the entire small gastric stromal tumor cohort (n = 74). In addition, 15% of small GISTs harbored previously undescribed BRAF-V600E hotspot mutations. No significant correlation was observed among the genotype, pathological features, and clinical classification.

CONCLUSIONS

Our data revealed a high overall mutation rate (~96%) in small GISTs, indicating that genetic alterations are common events in early GIST generation. We also identified a high frequency of oncogenic BRAF-V600E mutations (15%) in small GISTs, which has not been previously reported.

Efficacy of endoscopic ultrasound in the evaluation of small gastrointestinal stromal tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) with a diameter of < 2 cm are called small GISTs. Currently, endoscopic ultrasound (EUS) is widely used as a regular follow-up method for GISTs, which can also provide a preliminary basis for judging the malignancy potential of lesions. However, there are no studies on the accuracy of EUS to assess the malignant potential of small GISTs.

AIM

To evaluate the efficacy of EUS in the diagnosis and risk assessment of small GISTs.

METHODS

We collected data from patients with small GISTs who were admitted to Shengjing Hospital of China Medical University between October 2014 and July 2019. The accurate diagnosis and risk classifications of patients were based on the pathological assessment according to the modified National Institute of Health criteria after endoscopic resection or laparoscopic surgery. Preoperative EUS features (marginal irregularity, cystic changes, homogeneity, ulceration, and strong echogenic foci) were retrospectively analyzed. The assessment results based on EUS features were compared with the pathological features.

RESULTS

A total of 256 patients (69 men and 187 women) were enrolled. Pathological results included 232, 16, 7, and 1 very low-, low-, intermediate-, and high-risk cases, respectively. The most frequent tumor location was the gastric fundus (78.1%), and mitoses were calculated as > 5/50 high power field in 8 (3.1%) patients. Marginal irregularity, ulceration, strong echo foci, and heterogeneity were detected in 1 (0.4%), 2 (0.8%), 22 (8.6%), and 67 (65.1%) patients, respectively. However, cystic changes were not detected. Tumor size was positively correlated with the mitotic index (P < 0.001). Receiver operating curve analysis identified 1.48 cm as the best cut-off value to predict malignant potential (95% confidence interval: 0.824–0.956). EUS heterogeneity with tumor diameters > 1.48 cm was associated with higher risk classification (P < 0.05).

CONCLUSION

Small GISTs (diameters > 1.48 cm) with positive EUS features should receive intensive surveillance or undergo endoscopic surgery. EUS and dissection are efficient diagnostic and therapeutic approaches for small GISTs.

Clinical outcomes of endoscopic treatment for gastric gastrointestinal stromal tumors: a single-center study of 240 cases in China

BACKGROUND AND AIMS

Endoscopic resection (ER) gradually becomes an important treatment method for gastrointestinal stromal tumors (GISTs). The aim of this study is to evaluate the efficacy and safety of ER of gastric GISTs.

METHODS

This retrospective study included 240 patients with gastric GISTs who underwent ER at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2010 to December 2019. The clinicopathologic, endoscopic and follow-up data of the patients were collected and analyzed.

RESULTS

The mean maximum tumor diameter was 1.67 ± 1.00 cm (range 0.2-6.5 cm), of which 156 cases (65.00%) were small gastric GISTs (tumor diameter < 2 cm). A total of 43 patients (17.92%) had perioperative bleeding, including 40 cases (16.67%) of minor bleeding and three cases (1.25%) of major bleeding. Perioperative perforation occurred in 101 patients (42.08%), of which 51 patients (21.25%) were active perforation and 50 patients (20.83%) were passive perforation. The en bloc resection rate was 97.08% (233/240), and seven cases (2.92%) had piecemeal resection. There were three cases (1.92%) of small gastric GISTs at intermediate risk and one case (0.64%) at high risk. A total of 193 patients were followed up, and no tumor residual, recurrence or metastasis occurred within a median follow-up time of 30 months (range 1-127 months).

CONCLUSIONS

Endoscopic treatment for gastric GISTs is safe and effective. Piecemeal resection does not seem to be related to the patient's prognosis. Endoscopic resection can be performed if patients are willing to remove small gastric GISTs.

Gastrointestinal Stromal Tumor

Over the past 20 years, gastrointestinal stromal tumor (GIST) has evolved into an increasingly complex clinical entity with ever more challenges. While surgical resection is the gold standard, advancements in genetic testing, therapeutic options, immunotherapy, and management of metastatic disease necessitate a comprehensive, multimodal approach for these tumors. This chapter highlights the importance of genomic testing of GIST, the use of neoadjuvant and adjuvant therapy for localized disease, surgical principles for GIST, as well as current and new approaches for addressing metastatic disease.

Comparison of endoscopic full-thickness resection and cap-assisted endoscopic full-thickness resection in the treatment of small (≤1.5 cm) gastric GI stromal tumors

BACKGROUND AND AIMS

With the increasing incidence of small GI stromal tumors (GISTs), endoscopic full-thickness resection (EFTR) and cap-assisted EFTR (EFTR-C) have been suggested as 2 effective resection methods. We aimed to compare the outcomes of EFTR and EFTR-C for the treatment of small (≤1.5 cm) gastric GISTs.

METHODS

This retrospective study included 67 patients who underwent EFTR and 46 patients who underwent EFTR-C at Nanjing Drum Tower Hospital. Clinicopathologic features, adverse events (AEs), and outcomes were compared between the 2 groups. Univariate and multivariate linear and logistic regressions were used to analyze the effects of the procedure on the therapeutic outcomes of patients and adjusted for covariates in the multivariate analysis.

RESULTS

The tumor size in the EFTR group tended to be larger (P = .005). The resection time in the EFTR-C group was shorter than that in the EFTR group (38.3 ± 20.7 minutes vs 15.0 ± 11.8 minutes, P < .001), which retained statistical significance with adjustment for the covariates (adjusted mean difference, 22.2; 95% confidence interval, 15.0-29.4; P < .001). The R0 resection rate of the EFTR group was 94.0% and of the EFTR-C group 97.8% (P = .355). The EFTR-C group was superior to the EFTR group in terms of perioperative therapeutic outcomes, AEs, and postoperative recovery. No recurrence occurred in the EFTR and EFTR-C groups.

CONCLUSIONS

EFTR-C was found to be the preferable technique for small (≤1.5 cm) gastric GISTs with shorter operation times, lower AEs, faster postoperative recovery, and shorter hospitalization times as compared with EFTR.

The Diagnosis of Small Gastrointestinal Subepithelial Lesions by Endoscopic Ultrasound-Guided Fine Needle Aspiration and Biopsy

Endoscopic ultrasonography (EUS) has been widely accepted in the diagnosis of all types of tumors, especially pancreatic tumors, lymph nodes, and subepithelial lesions (SELs). One reason is that the examination can provide a detailed observation, with tissue samples being immediately obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Many SELs are detected incidentally during endoscopic examinations without symptoms. Most SELs are mesenchymal tumors originating from the fourth layer, such as gastrointestinal stromal tumors (GISTs), leiomyomas, and schwannomas. GISTs are potentially malignant. Surgical treatment is recommended for localized GISTs of ≥20 mm. However, the indications for the diagnosis and follow-up of GISTs of <20 mm in size are controversial. There are several reports on the rapid progression or metastasis of small GISTs. Therefore, it is important to determine whether a SEL is a GIST or not. The main diagnostic method is EUS-FNA. Recently, endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) using a new biopsy needle has been reported to obtain larger tissue samples. Additionally, various biopsy methods have been reported to have a high diagnostic rate for small GISTs. In local gastric SELs, regardless of the tumor size, EUS can be performed first; then, EUS-FNA/B or various biopsy methods can be used to obtain tissue samples for decision-making in relation to therapy and the follow-up period.

Small-sized gastrointestinal stromal tumors: Is there an association between expectant management and overall survival?

BACKGROUND

Small-sized gastrointestinal stromal tumors (GISTs) have limited malignant potential. Few studies evaluate the safety and efficacy of expectant management (EM) for patients presenting with small GIST.

METHODS

We queried the National Cancer Database to identify patients ≤65 years presenting with GISTs smaller than 3 cm in size between 2004 and 2015. Patients undergoing EM were 1:3 propensity score matched for relevant covariates to patients undergoing resection. Kaplan-Meier (KM) analysis of matched cohorts was used to evaluate the association between EM and overall survival (OS).

RESULTS

1330 patients met inclusion criteria; 966 (72.6%) had gastric GISTs. 1196 (89.9%) underwent resection; 134 (10.1%) EM. 117 patients undergoing EM were propensity-matched to 356 patients undergoing resection. There was no difference in 5-year OS between patients undergoing EM and those undergoing resection (95.7% vs 92.6%, p = 0.4882).

CONCLUSIONS

Survival for small GISTs is similar with expectant management or resection.

Novel endoscopic management for small gastric submucosal tumors: A single-center experience (with video)

BACKGROUND AND AIMS

To explore the novel treatment of small gastric submucosal tumors (SMTs) originating from the muscularis propria layer (SMT-MPs), we utilized endoscopic band ligation (EBL) with a precut of the covering mucosa.

METHODS

From Jan. 2012 to Dec. 2019, 111 patients with 124 gastric SMT-MPs were treated by precutting EBL. The clinical characteristics, operation duration, postoperative adverse events, and follow-up profiles were retrospectively collected.

RESULTS

A total of 124 tumors from 111 patients were successfully treated by precutting EBL. No adverse events, including perforation and major bleeding, were observed. Furthermore, 93 patients (83.8%) underwent endoscopic surveillance postoperatively, and during the follow-up period, no local recurrence was detected.

CONCLUSIONS

Precutting EBL appears to be a safe and simple method for removing gastric SMT-MPs < 16 mm (mainly indicated for potentially malignant GISTs), but further studies with longer follow-up are needed to assess the radicality of this intervention.

Recent Progress and Challenges in the Diagnosis and Treatment of Gastrointestinal Stromal Tumors

Simple Summary

Gastrointestinal stromal tumors (GIST) are potentially malignant tumors and require evidence-based surgical and/or medical treatment. Laparoscopy has similar safety and prognostic outcomes to those of laparotomy and is currently a standard procedure for localized GISTs. However, surgery for gastric GISTs less than 2 cm may be re-evaluated due to the indolent nature of the GIST and other competing risks among GIST patients. A work-up with endoscopy and endoscopic ultrasonography as well as endoscopic or percutaneous biopsy is important for the preoperative diagnosis of GISTs. Medical treatment with tyrosine kinase inhibitors is the mainstay for recurrent/metastatic GISTs. The activity of an individual drug is well correlated with gene alterations, and, in the era of precision medicine, cancer genome profiling should be considered before medical treatment.

Abstract

Gastrointestinal stromal tumors (GISTs) are the most frequent malignant mesenchymal tumors in the gastrointestinal tract. The clinical incidence of GISTs is estimated 10/million/year; however, the true incidence is complicated by frequent findings of tiny GISTs, of which the natural history is unknown. The initial work-up with endoscopy and endoscopic ultrasonography plays important roles in the differential diagnosis of GISTs. Surgery is the only modality for the permanent cure of localized GISTs. In terms of safety and prognostic outcomes, laparoscopy is similar to laparotomy for GIST treatment, including tumors larger than 5 cm. GIST progression is driven by mutations in KIT or PDGFRA or by other rare gene alterations, all of which are mutually exclusive. Tyrosine kinase inhibitors (TKIs) are the standard therapy for metastatic/recurrent GISTs. Molecular alterations are the most reliable biomarkers for TKIs and for other drugs, such as NTRK inhibitors. The pathological and genetic diagnosis prior to treatment has been challenging; however, a newly developed endoscopic device may be useful for diagnosis. In the era of precision medicine, cancer genome profiling by targeted gene panel analysis may enable potential targeted therapy even for GISTs without KIT or PDGFRA mutations.

Efficacy and safety of endoscopic resection in treatment of small gastric stromal tumors: A state-of-the-art review

Gastrointestinal stromal tumors can occur in any part of the gastrointestinal tract, but gastric stromal tumors (GSTs) are the most common. All GSTs have the potential to become malignant, and these can be divided into four different grades by risk from low to high: Very low risk, low risk, medium risk, and high risk. Current guidelines all recommend early complete excision of GSTs larger than 2 cm in diameter. However, it is not clear whether small GSTs (sGSTs, i.e., those smaller than 2 cm in diameter) should be treated as early as possible. The National Comprehensive Cancer Network recommends that endoscopic ultrasonography-guided (EUS-guided) fine-needle aspiration biopsy and imaging (computed tomography or magnetic-resonance imaging) be used to assess cancer risk for sGSTs detected by gastroscopy to determine treatment. When EUS indicates a higher risk of tumor, surgical resection is recommended. There are some questions on whether sGSTs also require early treatment. Many studies have shown that endoscopic treatment of GSTs with diameters of 2-5 cm is very effective. We here address whether endoscopic therapy is also suitable for sGSTs. In this paper, we try to explain three questions: (1) Does sGST require treatment? (2) Is digestive endoscopy a safe and effective means of treating sGST? and (3) When sGSTs are at different sites and depths, which endoscopic treatment method is more suitable?

Over-the-Scope Clip-Associated Endoscopic Muscular Dissection for Seven Cases of Small Gastric Submucosal Tumor: A Video-Based Case Series

Objectives

To evaluate the methodology, feasibility, safety, and efficacy of a novel method called over-the-scope clip- (OTSC-) associated endoscopic muscular dissection for small GSMT.

Methods

A pilot study on small GSMT diameter ≤ 1 cm was performed. OTSC-associated endoscopic muscular dissection was based on the requirement of OTSC apparatus and ESD technique; after ligaturing the bottom of small GSMT by OTSC, ESD was performed to resect the tumors, and the wounds of ESD were closed by clips finally. All the patients were followed up for more than 3 months, and the complications during and after OTSC-associated endoscopic muscular dissection were recorded.

Results

A total of 7 consecutive patients with small GSMT were included. All tumors were completely dissected without any perforation or infection during and after the procedure in all cases, while three patients had mild abdominal pain, and one experienced postoperative bleeding after the procedure which was treated by the endoscopy with titanium clips. All the patients were followed by endoscopy three months later, all the wounds healed well, and all the OTSCs were still in the gastric wall.

Conclusions

OTSC-associated endoscopic muscular dissection as a novel endoscopic interventional therapy should be a convenient, safe, and effective therapy for small GSMT. The short-time outcome is excellent, whereas long-term effect is unclear, and the further follow-up is needed to schedule.

Gastrointestinal stromal tumours

Gastrointestinal stromal tumours (GIST) have an incidence of ~1.2 per 10⁵ individuals per year in most countries. Around 80% of GIST have varying molecular changes, predominantly mutually exclusive activating KIT or PDGFRA mutations, but other, rare subtypes also exist. Localized GIST are curable, and surgery is their standard treatment. Risk factors for relapse are tumour size, mitotic index, non-gastric site and tumour rupture. Patients with GIST with KIT or PDGFRA mutations sensitive to the tyrosine kinase inhibitor (TKI) imatinib that are at high risk of relapse have improved survival with adjuvant imatinib treatment. In advanced disease, median overall survival has improved from 18 months to >70 months since the introduction of TKIs. The role of surgery in the advanced setting remains unclear. Resistance to TKIs arise mainly from subclonal selection of cells with resistance mutations in KIT or PDGFRA when they are the primary drivers. Advanced resistant GIST respond to second-line sunitinib and third-line regorafenib, as well as to the new broad-spectrum TKI ripretinib. Rare molecular forms of GIST with alterations involving NF1, SDH genes, BRAF or NTRK genes generally show primary resistance to standard TKIs, but some respond to specific inhibitors of the activated genes. Despite major advances, many questions in both advanced and localized disease remain unanswered.

Could computed tomography be used as a surrogate of endoscopic ultrasonography in the screening and surveillance of small gastric Gastrointestinal stromal tumors?

PURPOSE

To investigate whether computed tomography (CT) could be used for screening and surveillance of small gastric gastrointestinal stromal tumors (gGISTs).

METHOD

A total of 162 pathologically confirmed small gGISTs (≤2 cm) between September 2007 and November 2019 were retrospectively enrolled. Thirty-six lesions received contrast-enhanced CT after they were identified by endoscopy and EUS, and forty-three lesions received CT alone before surgery. The detection rate of CT for ≤1 cm gGISTs (micro-gGISTs) and 1-2 cm gGISTs (mini-gGISTs) was investigated, and the detection rate of CT alone was compared with that of CT following endoscopy and EUS. The relationship between EUS- and CT-detected high-risk features were assessed.

RESULTS

CT demonstrated a favorable detection rate for mini-gGISTs previously identified by EUS and endoscopy, whereas CT alone showed an inferior detection rate (100 % vs. 75 %, p =  0.02). CT showed a poor detection rate for micro-gGISTs, both for lesions received CT after identified by EUS and endoscopy, and those received CT alone (33.3 % vs. 14.8 %, p =  0.372). CT-detected heterogeneous enhancement pattern and presence of calcification were strongly correlated with heterogeneous echotexture (Spearman's ρ=0.66, p < 0.001) and echogenic foci (Spearman's ρ=0.79, p < 0.001) on EUS, respectively. CT-detected necrosis was moderately correlated with cystic spaces on EUS (Spearman's ρ=0.42, p = 0.02). No correlation was found between EUS- and CT- assessed irregular border.

CONCLUSIONS

CT could potentially be considered as a surrogate of EUS for surveillance of mini-gGISTs instead of micro-gGISTs, whereas couldn't be used as a screening modality for either micro- or mini-gGISTs.

TUFM-knockdown inhibits the migration and proliferation of gastrointestinal stromal tumor cells

Gastrointestinal stromal tumors (GISTs) are the most common pathologic type of mesenchymal tumor in the digestive tract. Patients with GIST face the risk of metastasis, postoperative recurrence and imatinib mesylate (IM) resistance. Mitochondrial Tu translation elongation factor (TUFM) is highly expressed in GISTs, and is associated with oncogenesis, progression and prognosis. There is evidence that TUFM is involved in tumor invasion and metastasis. However, the effect of TUFM on GIST-T1 cells and the IM-resistant GIST-IR cell line remains unclear. The present study aimed to evaluate the effects of TUFM on the proliferation, migration and apoptosis of GIST cells in vitro. TUFM short hairpin (sh)RNA expression plasmids were transfected into GIST-T1 and GIST-IR cells by electroporation. The expression levels of enhanced green fluorescent protein were observed by fluorescence microscopy to evaluate the electroporation efficiency. The expression levels of TUFM were detected by western blot analysis and reverse transcription-quantitative PCR. Cell proliferation was assessed by counting cells and using a Cell Counting Kit-8 assay. Cell migration was analyzed using wound healing and Transwell migration assays. Cell cycle distribution and late apoptosis were assessed by flow cytometry. TUFM shRNA expression plasmids were successfully transfected into the GIST cell line by electroporation. The transfection efficiency was >75%, and the TUFM gene silencing efficiency was 73.2±1.4%. TUFM-knockdown decreased the proliferation and migration capacity of GIST-T1 and GIST-IR cells. The proportion of cells in the pre-G1 stage was increased without change in the proportions of cells in the G₁, S and G₂/M stages after TUFM silencing in GIST-T1 and GIST-IR cells. TUFM may be related to GIST infiltration and metastatic recurrence, suggesting that TUFM may be an effective target for preventing the progression and metastasis of GISTs.

Which size is the best cutoff for primary small gastric gastrointestinal stromal tumor?

Background

The biological behavior of primary small gastric gastrointestinal stromal tumor (gGIST) is indolent. The cutoff size categorizing small gGIST continues to be controversial. To date, there is no consensus regarding whether it should be 1 cm, 2 cm, or another size. We aimed to find a new cutoff size.

Methods

Retrospective clinicopathological and prognosis data of patients with small gGIST from January 1998 to January 2015 were collected among five medical centers in southern China. Tumor size was divided into two groups: <1 cm (Mirco group) and 1-2 cm (Small group). We compared the clinicopathological index and prognosis between these two groups and identified a new cutoff size to define small gGIST.

Results

During this 18-year period, there were 276 patients with primary small gGIST treated at these five medical centers. The range of tumor size was 0.2-2.0 cm. The median tumor size was 1.0 cm. The range of the mitotic count was 0-70/50 high power fields (HPFs) with counts ≤5/50 HPFs in 259 patients (93.8%), 5< counts ≤10/50 HPFs in 7 patients (2.5%), and counts >10/50 HPFs in 10 patients (3.6%). The median follow-up time was 38 months (3-156 months). The 5-year overall survival rate was 98.7% in the entire group. Using Pearson correlation analysis, there was a positive correlation between the mitotic count and tumor size as a continuous variable (r=0.164, P=0.006). There were 137 patients in the Micro group and 139 cases in the Small group. In the Micro group, mitotic counts were ≤5/50 HPFs in 134 patients, 5< counts ≤10/50 HPFs in 0 patients, and counts >10/50 HPFs in 3 patients; mitotic counts in the Small group were counts ≤5/50 HPFs in 125 patients, 5< counts ≤10/50 HPFs in 7 patients, >10/50 HPFs in 7 patients. There was a statistically significant difference between these two groups (P=0.002); the Small group had more intermediate/high-risk cases. Using the receiver operating characteristic curve (ROC curve), we observed that 1.15 cm was the new cutoff size to separate low-risk cases and intermediate/high-risk cases (AUC =0.707, P=0.004, sensitivity =0.824, 1-specificity =0.429).

Conclusions

Primary small gGIST has a good prognosis; gGIST <1 cm can be regarded as benign tumors that only requires endoscopic ultrasonography (EUS) follow-up. The proportion of potential intermediate/high-risk disease is high for patients with 1-2 cm gGIST. These patients should be treated with caution and the tumors should be resected if necessary. These results indicate that 1.15 cm may be the new cutoff size to separate small gGIST from large gGIST, but further studies are needed for verification.

Gastrointestinal stromal tumour masquerading as a diverticular bleed

Gastrointestinal stromal tumours (GISTs) only account for a small percentage of gastrointestinal malignancies with a wide range of clinical presentations depending on the location and size of the tumour. Herein, we present the case of a 55-year-old woman with occult gastrointestinal bleeding (GIB) despite imaging and two separate oesophagogastroduodenoscopy colonoscopies. On double-balloon enteroscopy, an oozing diverticular-appearing lesion in the ileum was identified which on laparoscopy was connected to a large pelvic GIST. This case highlights the importance of considering GISTs in patients with occult GIB, as a high index of suspicion is required for diagnosis.

Clinicopathological Features and Prognosis of Small Gastric Gastrointestinal Stromal Tumors (GISTs)

BACKGROUND

The aim of the present study was to evaluate the safety of endoscopic surgery, the clinicopathological features, and prognoses of small gastric gastrointestinal stromal tumors (GISTs).

METHODS

Small gastric GIST patients (diameter: 0.10-2.00 cm) resected endoscopically in Zhongshan Hospital were retrospectively identified and clinicopathological features and outcomes were collected. The relationship between clinicopathological characteristics and tumor recurrence was analyzed. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal tumor diameter for predicting malignant potential.

RESULTS

All lesions were completely removed by endoscopy and En bloc resection was 98.5%. The most frequent location was the gastric fundus (60.3%) and the average diameter of all lesions was 1.20 cm (range: 0.10-2.00 cm). Mitoses were calculated as more than 5/50 HPF in 44 (6.8%) patients and nuclear atypia was moderate in 243 (37.5%) patients, severe in 1 (0.2%). Necrosis, mucosal infiltration, and vascular infiltration were detected in 8 (1.2%), 5 (0.7%), and 3 (0.5%) patients, respectively. Tumor size was positively correlated with mitotic index (P < 0.001) and nuclear atypia (P < 0.001). After a median follow-up of 54 months, four patients were confirmed local recurrence. ROC curve analysis identified 1.45 cm as the best cut-off value to predict malignant potential (95% CI: 0·694-0·774). Survival analysis showed that patients with tumor diameters larger than 1.45 cm were associated with more local recurrences after resection (P = 0.011).

CONCLUSIONS

Endoscopic surgery is feasible and safe for small gastric GISTs, especially those in favorable locations. Small gastric GISTs bear a good prognosis as a whole but those with diameters larger than 1.45 cm should receive more intensive surveillance or undergo endoscopic surgery.

Pancreaticoduodenectomy versus limited resection for duodenal gastrointestinal stromal tumors: a systematic review and meta-analysis

Background

By comparing the long-term prognostic outcomes after pancreaticoduodenectomy (PD) and limited resection (LR), this study aimed to investigate the optimal surgical modality for duodenal gastrointestinal stromal tumors (GISTs).

Methods

Two authors independently searched PubMed, Web of Science, Embase, and the Cochrane Library for published articles comparing the long-term prognostic and clinicopathological factors of duodenal GIST patients undergoing PD versus LR. Relevant information was extracted and analyzed.

Results

After screening, 10 items comprising 623 cases were eventually included. This meta-analysis explicitly indicated that PD treatment was associated with worse long-term prognosis (hazard ratio = 1.93; 95% confidence interval [CI], 1.39–2.69; p < 0.001; I² = 0) and more complications (odds ratio [OR] = 2.90; 95% CI, 1.90–4.42; p < 0.001; I² = 10%) than LR treatment. Nevertheless, for duodenal GISTs, PD was related to the following clinicopathological features: invasion of the second part of the duodenum (OR = 3.39; 95% CI, 1.69–6.79; p < 0.001; I² = 50%), high-degree tumor mitosis (> 5/50 high-power fields; OR = 2.24; 95% CI, 1.42–3.52; p < 0.001; I² = 0), and high-risk classification (OR = 3.17; 95% CI; 2.13–4.71; p < 0.001; I² = 0).

Conclusions

Since PD is associated with worse long-term prognosis and more complications, its safety and efficacy should be ascertained. Our findings recommend the use of LR to obtain negative incision margins when conditions permit it.

Electronic supplementary material

The online version of this article (10.1186/s12893-019-0587-4) contains supplementary material, which is available to authorized users.

Tenascin-C expression is significantly associated with the progression and prognosis in gastric GISTs

Tenascin-C (TNC), an extracellular matrix glycoprotein, has been implicated in progression of various types of cancer. However, few reports exist on TNC expression in gastrointestinal stromal tumors (GISTs). We here attempted to investigate the expression pattern and prognostic significance of TNC in gastric GISTs. We studied TNC expression in 122 gastric GISTs tissue samples by immunohistochemistry, and examined the correlations of TNC expression with clinicopathological parameters and survival of gastric GISTs. The TNC-high expression was observed in 30 (24.6%) of 122 of gastric GISTs. The high levels of TNC expression in gastric GISTs was significantly associated with tumor size (P < .001), multivisceral resection (P = .006), metastasis at initial diagnosis (P = .006), mitotic count (P = .002) and NIH risk classification (P = .015). The TNC mRNA and protein levels were found to significantly downregulated in tumors without progression compared to those tumors which occurred tumor progression during the follow-up period (P < .05). As for the prognostic analysis, it revealed that tumor size, mitotic count, surgical margins, multivisceral resection, and TNC expression were independent predictors of PFS for gastric GISTs (P < .05). The overexpression of TNC may be as a possible marker for the metastatic potential of gastric GISTs patients.

Prolonging Gastrointestinal-Stromal-Tumor-free life, an optimal suggestion of imatinib intervention ahead of operation

Background: Imatinib has been regarded as the first successful synthetic small molecule targeting at blocking tyrosine kinase. Its high efficacy stabilized disease in above 80% of chronic myeloid leukemia (CML) patients over 10 years survival. Due to the similar canceration of gastrointestinal stromal tumor (GIST) as to CML, imatinib has been approved to be used as first-line treatment. Study design: Our retrospective study was proposed to enroll 191 GIST patients with larger tumor size (≥8 cm) who preoperative accepted imatinib from those with direct operation. Analysis included demographics, cancer specific survival and relationship of their risk factors. Results: Male patients and gastrointestinal (GI) tract location took higher proportion in total cases, detection of KIT mutant took 89.7% among all traceable genetic testing. Patients with preoperative imatinib can achieve higher cancer specific survival (CSS) after both in 1 year and 3 years duration than their counterpart. Tumor size above its threshold of 8 cm would be a hazardous factor for poor prognosis. Conclusion: In conclusion, as for regressing tumor progression and creating operative chance, preoperative imatinib should be considered for the patients with high risk, although the precise duration of this intervention needs further validation.

The influence of marital status on the survival of patients with operable gastrointestinal stromal tumor: A SEER-based study

BACKGROUND

Marital status has been demonstrated as a predictive factor for prognosis in diverse malignancies, but its role in the survival of gastrointestinal stromal tumor (GIST) remains unclear.

MATERIAL AND METHODS

This study was aimed to investigate the impact of marital status on the overall survival (OS) and cancer-specific survival (CSS) of operable GIST cases, by using data from Surveillance, Epidemiology, and End Results (SEER) database. In total, 6582 GIST patients between 1973 and 2013 were identified from SEER database.

RESULTS

Univariate and multivariate analyses demonstrated the marital status as an independent predictive factor for survival. Married group had better 5-year OS and CSS than unmarried group (OS: 79.2% vs 71.3%, P < .001; CSS: 88.9% vs 84.8%, P < .001). And compared to married, divorced/separated, and single group, widowed group had the lowest 5-year OS and CSS (61.3% and 82.2%). Further subgroup analyses validated the relationship between marital status and survival among all SEER stages and different age groups. And additional sensitivity analyses according to other clinicopathological features confirmed that married cases had higher survival rate than unmarried cases.

CONCLUSION

In conclusion, marriage could be a protective prognostic factor for survival, and widowed patients had a higher risk of death.

Current clinical management of gastrointestinal stromal tumor

Gastrointestinal stromal tumors (GISTs) are the most common malignant subepithelial lesions (SELs) of the gastrointestinal tract. They originate from the interstitial cells of Cajal located within the muscle layer and are characterized by over-expression of the tyrosine kinase receptor KIT. Pathologically, diagnosis of a GIST relies on morphology and immunohistochemistry [KIT and/or discovered on gastrointestinal stromal tumor 1 (DOG1) is generally positive]. The prognosis of this disease is associated with the tumor size and mitotic index. The standard treatment of a GIST without metastasis is surgical resection. A GIST with metastasis is usually only treated by tyrosine kinase inhibitors without radical cure; thus, early diagnosis is the only way to improve its prognosis. However, a GIST is usually detected as a SEL during endoscopy, and many benign and malignant conditions may manifest as SELs. Conventional endoscopic biopsy is difficult for tumors without ulceration. Most SELs have therefore been managed without a histological diagnosis. However, a favorable prognosis of a GIST is associated with early histological diagnosis and R0 resection. Endoscopic ultrasonography (EUS) and EUS-guided fine needle aspiration (EUS-FNA) are critical for an accurate diagnosis of SELs. EUS-FNA is safe and effective in enabling an early histological diagnosis and adequate treatment. This review outlines the current evidence for the diagnosis and management of GISTs, with an emphasis on early management of small SELs.

Distinctive features of gastrointestinal stromal tumors arising from the colon and rectum

Background

Colon and rectal gastrointestinal stromal tumors (GISTs) are rare and poorly characterized. Because the majority of treatment guidelines for GISTs are extrapolated from tumors of gastric and small bowel origin, our aim was to better characterize the unique clinicopathologic features and prognostic factors of colon and rectal GISTs to guide clinical care.

Methods

The National Cancer Data Base (NCDB) was queried from 2006 to 2013 for cases of GISTs in the stomach, colon, and rectum. Patient demographics, clinical characteristics, and survival were compared.

Results

A total of 11,302 gastric GISTs were compared to 398 colon and 393 rectal GISTs. After propensity matching, compared to gastric GISTs, rectal GISTs had improved overall survival (HR =0.695, P=0.0264), while colon GISTs had worse overall survival (HR =1.6, P=0.0005). Surgical treatment for rectal GISTs was more likely to be local excision compared to colonic GISTs (51.1% vs. 8.4%, P<0.0001). Colon and gastric GISTs were less likely to receive systemic therapy compared to rectal GISTs (34.2% vs. 34.0% vs. 55.2%, P<0.0001). Adjuvant systemic therapy conveyed a survival advantage to rectal GISTs (HR =0.47, P=0.042) but not colon GISTs. There was a negative impact of adjuvant therapy on survival for colon GISTs <5 cm (HR =3.41, P=0.032).

Conclusions

Patients with rectal GISTs live longer than those with colon and gastric GISTs, and adjuvant therapy prolongs their survival. Many patients with colon GISTs are treated with adjuvant therapy despite a detrimental effect on survival. Tumor biology of colon and rectal GISTs needs to be better studied to tailor treatment.

Clinical and pathological features of "small" GIST (≤2 cm). What is their prognostic value?

INTRODUCTION

Small GIST (<2 cm) are tumors whose biological behavior is benign and frequently involutes. Despite their increasing incidence, few studies have addressed the characteristics of these GIST. The aim of this work is to clarify the management of this entity.

PATIENTS AND METHOD

The characteristics of ≤2 cm GIST were initially described, and then compared with those >2 cm. This series comprises 104 patients and they were divided according to tumor size in 4 groups: tumors which are ≤2 cm (group 1, G1), >2 and ≤ 5 cm (G2), >5 and ≤ 10 cm (G3) and >10 cm (G4).

RESULTS AND DISCUSSION

Most of small GIST were asymptomatic and incidental, and were located in the stomach. There is an association between patients with associated tumors and asymptomatic GIST. A high overall mortality rate of up to 40% is observed being disease-specific mortality 4.5%. The disease-specific mortality increases proportionally with size. The overall survival (OS) at 5 years are lower for both <2 cm (61%) and >10 cm (53%) than the rest (85-91%). When analyzing the impact of tumor association on <2 cm GIST, we observed that the OS of patients with non-associated tumors was much higher than in the associated ones (90% vs 32% at 5 years, respectively), while no differences were observed in the disease specific survival.

CONCLUSIONS

Small GIST are tumors that are very often incidentally discovered in the course of complementary examinations. Its prognosis is very good, but it depends on the associated tumor.

Racial Disparity in Gastrointestinal Cancer Risk

Cancer from the gastrointestinal tract and its associated excretory organs will occur in more than 300,000 Americans in 2017, with colorectal cancer responsible for >40% of that burden; there will be more than 150,000 deaths from this group of cancers in the same time period. Disparities among subgroups related to the incidence and mortality of these cancers exist. The epidemiology and risk factors associated with each cancer bear out differences for racial groups in the United States. Esophageal adenocarcinoma is more frequent in non-Hispanic whites, whereas esophageal squamous cell carcinoma with risk factors of tobacco and alcohol is more frequent among blacks. Liver cancer has been most frequent among Asian/Pacific Islanders, chiefly due to hepatitis B vertical transmission, but other racial groups show increasing rates due to hepatitis C and emergence of cirrhosis from non-alcoholic fatty liver disease. Gastric cancer incidence remains highest among Asian/Pacific Islanders likely due to gene-environment interaction. In addition to esophageal squamous cell carcinoma, cancers of the small bowel, pancreas, and colorectum show the highest rates among blacks, where the explanations for the disparity are not as obvious and are likely multifactorial, including socioeconomic and health care access, treatment, and prevention (vaccination and screening) differences, dietary and composition of the gut microbiome, as well as biologic and genetic influences. Cognizance of these disparities in gastrointestinal cancer risk, as well as approaches that apply precision medicine methods to populations with the increased risk, may reduce the observed disparities for digestive cancers.

Surgical Management of Adolescents and Young Adults With Gastrointestinal Stromal Tumors: A US Population-Based Analysis

Importance

There is a dearth of population-based evidence regarding outcomes of the adolescent and young adult (AYA) population with gastrointestinal stromal tumors (GISTs).

Objectives

To describe a large cohort of AYA patients with GISTs and investigate the effect of surgery on GIST-specific survival (GSS) and overall survival (OS).

Design, Setting, and Participants

This retrospective cohort study of 392 AYA patients and 5373 older adult (OA) patients in the Surveillance, Epidemiology, and End Results (SEER) database with GISTs histologically diagnosed from January 1, 2001, through December 31, 2013, with follow-up through December 31, 2015, compared the baseline characteristics of AYA (13-39 years old) and OA (≥40 years old) patients and among AYA patients stratified by operative management. Kaplan-Meier estimates were used for OS analyses. Cumulative incidence functions were used for GSS analysis. The effect of surgery on survival was evaluated with a multivariable Fine-Gray regression model.

Exposure

Tumor resection.

Main Outcomes and Measures

GIST-specific survival and OS.

Results

This study included 392 AYA and 5373 OA patients diagnosed with GISTs (207 [52.8%] male AYA patients, 2767 [51.5%] male OA patients, 277 [70.7%] white AYA patients, and 3661 [68.1%] white OA patients). Compared with the OA patients, more AYA patients had small-intestine GISTs (139 [35.5%] vs 1465 [27.3%], P = .008) and were managed operatively (332 [84.7%] vs 4212 [78.4%], P = .003). Multivariable analysis of AYA patients found that nonoperative management was associated with a more than 2-fold increased risk of death from GISTs (subdistribution hazard ratio, 2.27; 95% CI, 1.21-2.25; P = .01). On subset analysis of 349 AYA patients with tumors of the stomach and small intestine, small-intestine location was associated with improved survival (OS: 91.1% vs 77.2%, P = .01; GSS: 91.8% vs 78.0%, P = .008). On subset analysis of 91 AYA patients with metastatic disease, operative management was associated with improved survival (OS: 69.5% vs 53.7%, P = .04; GSS: 71.5% vs 56.7%, P = .03).

Conclusions and Relevance

This study found that AYA patients are more likely to undergo surgical management than OA patients. Operative management is associated with improved OS and GSS in AYA patients, including those with metastatic disease.

[Clinical and pathological features of gastrointestinal stromal tumors (GIST) in a single institution: A descriptive study and review of the literature]

INTRODUCTION

This study was aimed to assess the main clinical, pathological and therapeutic characteristics of a cohort of gastrointestinal stromal tumors (GIST).

METHODS

Observational study including 66 patients diagnosed with GIST admitted to our hospital between 2002 and 2015. Parameters related to medical history, clinical manifestations, medical and surgical treatment, histopathology, and morbi-mortality were studied. A review of the literature was included to correlate with the results.

RESULTS

The most frequent location of GIST in our patients was the stomach (65.2%), in which the gastric fondo was the predominant region. The most common clinical manifestation was gastrointestinal hemorrhage (45.5%), followed by incidental finding after imaging or invasive procedures (33.3%). 58 patients underwent surgery (90.6%), 15.5% were urgent. A total of 69% of the GISTs had a size between 2 and 10cm. The one-year mortality was 7.9%, all cases related to local or remote extension, or surgical complications.

CONCLUSION

There is a large clinical variability among GIST cases. The first choice of treatment is surgery, which is feasible in most cases and should be as conservative as possible. The prognosis varies depending on the size and proliferation index, thus close follow-up should be performed. No tumor marker is clearly associated with a poor prognosis. New molecular biology studies are needed in order to find therapeutic targets.

Orai1 mediates tumor-promoting store-operated Ca2+ entry in human gastrointestinal stromal tumors via c-KIT and the extracellular signal-regulated kinase pathway

Gastrointestinal stromal tumors originate from interstitial cells of Cajal, the pacemaker cells of the gut. Ca²⁺ regulates the pacemaker activity of interstitial cells of Cajal. Store-operated Ca²⁺ entry mediates the majority of Ca²⁺ entry in most cancer cells and may be a factor in regulating intracellular Ca²⁺ in interstitial cells of Cajal and gastrointestinal stromal tumors. Therefore, a blockade of this mechanism may affect the progression of gastrointestinal stromal tumors. Orai1 is the pore subunit of store-operated Ca²⁺ channels. Here, we reported that Orai1 was overexpressed in gastrointestinal stromal tumor tissues and was positively correlated with a high-risk grade in gastrointestinal stromal tumor patients. Furthermore, upon Orai1 silencing, the functional store-operated Ca²⁺ entry in gastrointestinal stromal tumor cells was decreased, indicating that the function of store-operated Ca²⁺ entry was mediated by Orai1. Inhibition of Orai1-mediated store-operated Ca²⁺ entry by Orai1 silencing or store-operated Ca²⁺ entry blockers (SKF-96365 and 2-aminoethyl diphenylborate) induced obvious cell proliferation suppression, cell-cycle distribution, and apoptosis stimulation in GIST-T1 cells. Conversely, Orai1 overexpression increased store-operated Ca²⁺ entry and cell proliferation in GIST882 cells. In addition, we found that activation of c-KIT and the extracellular signal-regulated kinase pathway participated in the oncogenic functions of Orai1-mediated store-operated Ca²⁺ entry in gastrointestinal stromal tumor cells. These results revealed that Orai1-mediated store-operated Ca²⁺ entry is critical for gastrointestinal stromal tumor cell proliferation via c-KIT and ERK signaling pathway activation. Orai1-mediated store-operated Ca²⁺ entry plays an oncogenic role and may be a novel prognostic factor and therapeutic target for patients with gastrointestinal stromal tumors.

The cut-off value of tumor size and appropriate timing of follow-up for management of minimal EUS-suspected gastric gastrointestinal stromal tumors

Backgroud

The detectable rate of minimal gastric GISTs has continuously increased. While the surveillance and management of GIST <2 cm have been deemed controversial or lack evidence-based approaches.  The aim of the current study is to propose a cut-off value of tumor size for treatment policy and the appropriate timing for endoscopic ultrasonography (EUS) follow-up in the minimal EUS-suspected gastric GIST patients.

Methods

A single-institution retrospective study was performed. 69 patients with EUS-suspected gastric GISTs were studied from November 2008 to March 2015. 69 patients with minimal gastric GISTs ≤2 cm diagnosed by EUS were followed for a mean period of 29 months (range, 12 to 70). An at least 20% increase of the maximal diameter of the tumors was set as a significant change.

Results

During follow-up, Of the 69 minimal EUS-suspected GISTs, 16 (23.2%) showed significant changes in size. 11 out of 69 GISTs (15.9%), 6 out of 43 GISTs (14.0%), 7 out of 30 GISTs (23.3%) showed significant changes in size, at 1 year, 2 years, and more than 3 years respectively. The receiver operating characteristic curve analysis showed that the tumor size cut-off was 9.5 mm. Only 4.7 and 3.7% of gastric EUS-suspected GISTs of <9.5 mm in size showed significant changes at 1 year and 2 years, while 9.5% at more than 3 years. 34.6, 31.3 and 55.6% of gastric EUS-suspected GISTs of ≥ 9.5 mm in size showed significant changes at 1 year, 2 years and more than 3 years.

Conclusions

Minimal EUS-suspected GISTs, larger than 9.5 mm may be associated with significant progression. The patients with a ≥ 9.5 mm GIST should have a EUS 6–12months, while <9.5 mm GIST may have a EUS extended to every 2–3 years.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0567-4) contains supplementary material, which is available to authorized users.

Surgical treatment of gastrointestinal stromal tumors of the stomach: current status and future perspective

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract, with the majority found in the stomach. Surgical resection of the primary gastric GISTs with complete resection margin has been the forefront of curative treatment. The indications for surgical resection are usually related to symptomatic gastric GISTs at presentation. Primary gastric GISTs resection performed conventionally through an open surgery can now be frequently achieved by minimal invasive surgery with similar oncological outcome. Surgeon's selection of the type of surgical techniques such as open, laparoscopic and endoscopic resections depends on the site, size and local invasion of gastric GISTs to the adjacent organ. Similarly those factors dictate the extent of gastric resections in the form of wedge, partial or total gastrectomy. All these inherent tumor factors (size and mitotic index), patient factors (older age, male) and surgical factors (incomplete resection margin, tumor rupture or spillage) play an important role in stratifying the malignant potential risk of primary gastric GISTs and their chances of recurrence. The understanding of gene mutation driving the growth of GISTs and the discovery of tyrosine kinase inhibitors (TKIs) has altered the surgical management of advanced and metastatic GISTs. Multi-modal therapy incorporating the surgical resection of GISTs and utilizing the molecular targeted therapy in the adjuvant, neoadjuvant and palliative settings can offer optimal personalized outcome and prolong patient's overall survival (OS).