Gastrointestinal stromal tumors: the role of the gastroenterologist in diagnosis and risk stratification

Factors associated with gastrointestinal stromal tumor rupture and pathological risk: A single-center retrospective study

BACKGROUND

Gastrointestinal stromal tumor (GIST) is a rare gastrointestinal mesenchymal tumor with potential malignancy. Once the tumor ruptures, regardless of tumor size and mitotic number, it can be identified into a high-risk group. It is of great significance for the diagnosis, treatment, and prognosis of GIST if non-invasive examination can be performed before surgery to accurately assess the risk of tumor.

AIM

To identify the factors associated with GIST rupture and pathological risk.

METHODS

A cohort of 50 patients with GISTs, as confirmed by postoperative pathology, was selected from our hospital. Clinicopathological and computed tomography data of the patients were collected. Logistic regression analysis was used to evaluate factors associated with GIST rupture and pathological risk grade.

RESULTS

Pathological risk grade, tumor diameter, tumor morphology, internal necrosis, gas-liquid interface, and Ki-67 index exhibited significant associations with GIST rupture (P < 0.05). Gender, tumor diameter, tumor rupture, and Ki-67 index were found to be correlated with pathological risk grade of GIST (P < 0.05). Multifactorial logistic regression analysis revealed that male gender and tumor diameter ≥ 10 cm were independent predictors of a high pathological risk grade of GIST [odds ratio (OR) = 11.12, 95% confidence interval (95%CI): 1.81-68.52, P = 0.01; OR = 22.96, 95%CI: 2.19-240.93, P = 0.01]. Tumor diameter ≥ 10 cm, irregular shape, internal necrosis, gas-liquid interface, and Ki-67 index ≥ 10 were identified as independent predictors of a high risk of GIST rupture (OR = 9.67, 95%CI: 2.15-43.56, P = 0.01; OR = 35.44, 95%CI: 4.01-313.38, P < 0.01; OR = 18.75, 95%CI: 3.40-103.34, P < 0.01; OR = 27.00, 95%CI: 3.10-235.02, P < 0.01; OR = 4.43, 95%CI: 1.10-17.92, P = 0.04).

CONCLUSION

Tumor diameter, tumor morphology, internal necrosis, gas-liquid, and Ki-67 index are associated with GIST rupture, while gender and tumor diameter are linked to the pathological risk of GIST. These findings contribute to our understanding of GIST and may inform non-invasive examination strategies and risk assessment for this condition.

Peculiar Presentation of Gastrointestinal Stromal Tumor in a Patient With Early Satiety

Gastrointestinal stromal tumors (GISTs) are one of the most common, potentially malignant, subepithelial lesions identified in the gastrointestinal tract. Hypothesized to derive from the interstitial cells of Cajal (ICC), GISTs commonly demonstrate gain of function mutations in proto-oncogenic receptor tyrosine kinase CD117 (KIT). Depending on mitotic activity and tumor size characteristics, GISTs may transform from benign to malignant neoplasms. Increasing evidence suggests that early identification of a GIST is paramount for optimal prognostic outcomes. We present a rare case of a GIST located in the uncinate pancreas identified via endoscopic ultrasound (EUS) and diagnosed with an EUS-guided fine needle aspiration (EUS-FNA) biopsy.

ACG Clinical Guideline: Diagnosis and Management of Gastrointestinal Subepithelial Lesions

Subepithelial lesions (SEL) of the GI tract represent a mix of benign and potentially malignant entities including tumors, cysts, or extraluminal structures causing extrinsic compression of the gastrointestinal wall. SEL can occur anywhere along the GI tract and are frequently incidental findings encountered during endoscopy or cross-sectional imaging. This clinical guideline of the American College of Gastroenterology was developed using the Grading of Recommendations Assessment, Development, and Evaluation process and is intended to suggest preferable approaches to a typical patient with a SEL based on the currently available published literature. Among the recommendations, we suggest endoscopic ultrasound (EUS) with tissue acquisition to improve diagnostic accuracy in the identification of solid nonlipomatous SEL and EUS fine-needle biopsy alone or EUS fine-needle aspiration with rapid on-site evaluation sampling of solid SEL. There is insufficient evidence to recommend surveillance vs resection of gastric gastrointestinal stromal tumors (GIST) <2 cm in size. Owing to their malignant potential, we suggest resection of gastric GIST >2 cm and all nongastric GIST. When exercising clinical judgment, particularly when statements are conditional suggestions and/or treatments pose significant risks, health-care providers should incorporate this guideline with patient-specific preferences, medical comorbidities, and overall health status to arrive at a patient-centered approach.

A Gastroenterologist's Approach to the Diagnosis and Management of Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract. These tumors have been shown to harbor oncogenic mutations of the c-kit tyrosine kinase receptor or platelet-derived growth factor receptor alpha (PDGFRA). Immunohistochemical analysis of GISTs allows for the differentiation of these tumors from other mesenchymal tumors of the GI tract such as leiomyomas and leiomyosarcomas. All GISTs have the potential to behave in a malignant fashion. Tumor location, size, and mitotic index are factors used to predict the risk of malignant behavior. Endoscopy and endoscopic ultrasound play a critical role in the diagnosis of GISTs and can yield important information to further risk-stratify tumors and determine management. This article provides a gastroenterologist's perspective on the diagnosis and management of GISTs.

Association Between the Nutritional Risk and the Survival Rate in Newly Diagnosed GIST Patients

Background: Currently, the incidence of gastrointestinal stromal tumors (GIST) is increasing rapidly worldwide. Malnutrition may increase the risk of perioperative complications and affect the prognosis of patients. However, previous studies on the nutritional status of GIST patients and its impact on prognosis are limited. Therefore, this study aims to explore the incidence of malnutrition in newly diagnosed GIST patients, the proportion of participants in need of nutritional intervention, and the relationship between nutritional status and overall survival (OS). Methods: We retrospectively analyzed the clinical data of GIST patients treated in our hospital from January 2014 to January 2018. Nutritional Risk Screening 2002 (NRS2002) and Patient-Generated Subjective Global Assessment (PG-SGA) were used to assess the nutritional status of all patients. This study was to investigate the clinical significance of PG-SGA by analyzing the relationship between PG-SGA score and OS. Results: A total of 1,268 newly diagnosed GIST patients were included in this study, of which 77.76% were at risk of malnutrition (NRS2002 score ≥ 3), and the incidence of malnutrition was 10.09% (PG-SGA score ≥ 4). Meanwhile, we found 2.29% of the patients required urgent nutritional support (PG-SGA score ≥ 9). Multivariate analysis showed that age (p = 0.013), BMI (p = 0.001), weight loss (p = 0.001), anemia (p = 0.005), pre-albumin (p = 0.010), albumin (p = 0.002), tumor location (p = 0.001), tumor size (p = 0.002), and NIH classification (p = 0.001) were risk factors for nutritional status. The prognosis was significantly in GIST patients with different PG-SGA score at admission (p < 0.05). Conclusion: This study suggested that malnutrition is common in newly diagnosed GIST patients, and the higher the PG-SGA score, the worse the clinical outcome.

Full-thickness resection device (FTRD) for treatment of upper gastrointestinal tract lesions: the first international experience

Background and study aims  The Full-Thickness Resection Device (FTRD) provides a novel treatment option for lesions not amenable to conventional endoscopic resection techniques. There are limited data on the efficacy and safety of FTRD for resection of upper gastrointestinal tract (GIT) lesions. Patients and methods  This was an international multicenter retrospective study, including patients who had an endoscopic resection of an upper GIT lesion using the FTRD between January 2017 and February 2019. Results  Fifty-six patients from 13 centers were included. The most common lesions were mesenchymal neoplasms (n = 23, 41 %), adenomas (n = 7, 13 %), and hamartomas (n = 6, 11 %). Eighty-four percent of lesions were located in the stomach, and 14 % in the duodenum. The average size of lesions was 14 mm (range 3 to 33 mm). Deployment of the FTRD was technically successful in 93 % of patients (n = 52) leading to complete and partial resection in 43 (77 %) and 9 (16 %) patients, respectively. Overall, the FTRD led to negative histological margins (R0 resection) in 38 (68 %) of patients. A total of 12 (21 %) mild or moderate adverse events (AEs) were reported. Follow-up endoscopy was performed in 31 patients (55 %), on average 88 days after the procedure (IQR 68-138 days). Of these, 30 patients (97 %) did not have any residual or recurrent lesion on endoscopic examination and biopsy, with residual adenoma in one patient (3 %). Conclusions  Our results suggest a high technical success rate and an acceptable histologically complete resection rate, with a low risk of AEs and early recurrence for FTRD resection of upper GIT lesions.

Endoscopic full-thickness resection of gastric subepithelial tumors with the gFTRD-system: a prospective pilot study (RESET trial)

BACKGROUND

Gastric subepithelial tumors (SET) are rare and usually benign. However, up to 13% are malignant. Histology after conventional biopsy often is inconclusive. Surveillance endoscopies are the consequence in the majority of gastric SET cases. For SET arising from deeper layers endoscopic resection (ER) with the standard techniques is difficult and associated with the risk of perforation. The RESET trial further evaluates feasibility, efficacy and safety of clip-assisted endoscopic full-thickness resection (EFTR) for gastric SET using the novel gastric full-thickness-resection device (gFTRD).

MATERIALS AND METHODS

The RESET trial was initiated in March 2017 (NCT03096236) and designed as prospective observational multicenter pilot trial. Gastric SET up to 15 mm were included. Primary endpoint was technical success (complete enbloc resection). Secondary endpoints were R0 resection, full-thickness resection, adverse events and recurrency at 3-months follow-up. For resection we used the gFTRD (Ovesco Endoscopy, Tübingen, Germany).

RESULTS

29 patients underwent gastric EFTR. Histology prior EFTR after conventional biopsy could define histological tumor type in only 31.2%. Primary endpoint was reached in 89.7%. Histology of the full-thickness-resection specimen could define histological tumor type in 100%. 76% of all SET could be resected histologically complete (R0) and a full-thickness-resection specimen could be obtained in 65.5%. In 31% periprocedural minor bleeding was observed and managed endoscopically. Follow-up was available in 79.3% (OTSC detachment in 78.3%, OTSC in position in 21.7%). No signs of residual or recurrent tumors were observed after 3 months.

CONCLUSION

EFTR of gastric SET with gFTRD is feasible and safe. EFTR allows a definite histological diagnosis (including sufficient risk stratification in case of GIST or NET) in contrast to conventional biopsy. R0-resection is possible in most cases and might obviate the need for further surveillance endoscopies for selected patients.

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.

Management of gastric subepithelial tumors: The role of endoscopy

With the wide use of esophagogastroduodenoscopy, the incidence of gastric subepithelial tumor (SET) diagnosis has increased. While the management of large or symptomatic gastric SETs is obvious, treatment of small (≤ 3 cm) asymptomatic gastric SETs remains inconclusive. Moreover, the presence of gastrointestinal stromal tumors with malignant potential is of concern, and endoscopic treatment of gastric SETs remains a subject of debate. Recently, numerous studies have demonstrated the feasibility of endoscopic treatment of gastric SETs, and have proposed various endoscopic procedures including endoscopic submucosal dissection, endoscopic muscularis dissection, endoscopic enucleation, endoscopic submucosal tunnel dissection, endoscopic full-thickness resection, and a hybrid approach (the combination of endoscopy and laparoscopy). In this review article, we discuss current endoscopic treatments for gastric SETs as well as the advantages and limitations of this type of therapy. Finally, we predict the availability of newly developed endoscopic treatments for gastric SETs.

Diagnosis value of CD117 and PDGFRA, alone or in combination DOG1, as biomarkers for gastrointestinal stromal tumors

BACKGROUND

To explore the diagnostic values of CD117 and PDGFRA protein expressions, used alone or in combination with DOG1 protein, for gastrointestinal stromal tumors (GIST).

METHODS

The CD117, PDGFRA and DOG1 protein expressions in 99 GIST specimens and 25 non-GIST specimens were retrospectively determined, and the potential correlations were analyzed.

RESULTS

The positive rates of CD117, PDGFRA, and DOG1 expressions were 93.94% (93/99), 53.54% (53/99), and 90.91% (90/99) in GIST group and 4.00% (1/25), 4.00% (1/25), and 12.00% (3/25) in non-GIST group (all P<0.05). The expressions of CD117, PDGFRA, and DOG1 had no significant correlation with clinicopathological parameters including gender, age, tumor diameter, tumor location, histotype, and risk degree (all P>0.05). The sensitivities of CD117, PDGFRA, DOG1, CD117 + DOG1, PDGFRA + DOG1, and CD117 + PDGFRA + DOG1 were 0.989, 0.981, 0.968, 0.960, 0.933, and 0.961 in judging GIST, respectively, and the specificities were 0.800, 0.343, 0.710, 0.840, 0.947, and 0.955, respectively. The areas under the ROC curve (AUC) in these six groups were 0.945, 0.748, 0.895, 0.895, 0.840, and 0.975, respectively.

CONCLUSIONS

The populations that may benefit more from the detection of CD117, PDGFRA, and DOG1 protein expression for GIST need to be further identified. Detection of CD117 and PDGFRA protein, alone or in combination with DOG1, may increase the accuracy of GIST diagnosis.

Optimizing surgical and imatinib therapy for the treatment of gastrointestinal stromal tumors

INTRODUCTION

The discovery of activating KIT and PDGFRα mutations in gastrointestinal stromal tumors (GISTs) represented a milestone as it allowed clinicians to use tyrosine kinase inhibitors, like imatinib, to treat this sarcoma. Although surgery remains the only potentially curative treatment, patients who undergo complete resection may still experience local recurrence or distant metastases. Therapeutic strategies that combine surgical resection and adjuvant imatinib may represent the best treatment to maximize patient outcomes. In addition to the use of imatinib in the adjuvant and metastatic settings, neoadjuvant imatinib, employed as a cytoreductive therapy, can decrease tumor volume, increase the probability of complete resection, and may reduce surgery-related morbidities. Thus, selected patients with metastatic disease may be treated with a combination of preoperative imatinib and metastasectomy. However, it is critical that patients with GIST be evaluated by a multidisciplinary team to coordinate surgery and targeted therapy in order to maximize clinical outcomes.

DISCUSSION

Following a systematic literature review, we describe the presentation, diagnosis, and treatment of GIST, with a discussion of the risk assessment for imatinib therapy. The application of surgical options, combined with adjuvant/neoadjuvant or perioperative imatinib, and their potential impact on survival for patients with primary, recurrent, or metastatic GIST are discussed.

Endoscopic ultrasonography for gastrointestinal submucosal lesions

Advances in endoscopic imaging technology have led to the detection of more cases of gastrointestinal submucosal lesions (SMLs). Endoscopic ultrasonography (EUS) was previously known as the best imaging procedure to characterize SMLs. However, the progress of endoscopic submucosal dissection (ESD) has raised some new questions concerning the role of EUS in the diagnosis of SMLs. What is the diagnostic accuracy of EUS for SMLs? How is the nature of SMLs determined? How is the layer of origin identified? What is the preoperative value of EUS for ESD? In this review, we will discuss the endosonographic features of SMLs, the diagnostic accuracy of EUS, the ability of EUS to distinguish benign and malignant SMLs, the value of EUS-guided fine-needle aspiration (FNA), and the value of EUS in clinical surveillance.

A multidisciplinary approach to the diagnosis and treatment of gastrointestinal stromal tumor

Management of patients with gastrointestinal stromal tumor (GIST) typically involves a combination of surgical, pathologic, and pharmacologic interventions. Gastroenterologists are often the first specialists to encounter patients presenting with GIST and are therefore responsible for facilitating early intervention strategies. Although patients with gastric or small-bowel GISTs typically present with symptoms, a diagnosis of GIST should be considered whenever a submucosal lesion is seen endoscopically. Visualization by standard endoscopy often can determine tumor location and size, although endoscopic ultrasound (EUS) is the most accurate imaging technique for submucosal lesions. Biopsy techniques that yield sufficient tumor samples for diagnostic studies, such as EUS-guided fine needle aspiration, are essential, although other approaches such as EUS-guided core needle biopsy may increase diagnostic yield for subepithelial lesions. Pathology assessment should include immunohistochemical staining for KIT and possibly DOG1 expression, and mutational analysis can have prognostic and predictive value for certain patients. R0 resection is the goal for patients with localized or potentially resectable tumors, which often can be accomplished by laparoscopic resection, even for larger tumors. Medical oncologists play a key role in assessing risk of recurrence after resection and optimizing tyrosine kinase inhibitor therapy in the adjuvant or metastatic setting. Cytoreductive surgery may have value for patients with recurrent or metastatic GIST who exhibit stable disease or respond to tyrosine kinase inhibitor therapy. A coordinated multidisciplinary approach over the course of the disease will serve to enhance communication among GIST team members, reduce risk of progression, and optimize outcomes.