Current issues in gastrointestinal stromal tumors: incidence, molecular biology, and contemporary treatment of localized and advanced disease

A rare case of extragastrointestinal stromal tumor of vocal cord - case report

Gastrointestinal stromal tumors (GISTs) are the mesenchymal tumors of the gastrointestinal tract. Extra Gastrointestinal stromal tumors (EGISTs) are rare neoplasms that occur outside the gastrointestinal tract [1]. Miettinen et al. [2] described the first EGIST in 1999. EGIST accounts for 10% of all GISTs [3]. The main distinction between GIST and EGIST is the site of origin of the primary tumor, as GIST occurs throughout the GI tract, from the esophagus to the anus, whereas EGIST is a tumor without any connection with the intestinal wall and are reported in the retroperitoneum, mesentery, and omentum [4]. Hu et al. [5] reported a first case report of EGIST of larynx.We present a second case report of Extra-gastrointestinal stromal tumor of larynx a 47-year-old male reported to ENT Department Command Hospital Central Command Lucknow with complaints of Hoarseness. On examination found to have right vocal cord growth for which he underwent excision of right vocal cord growth. Histopathological examination showed typical of a spindle-cell GIST, showing strong immunoreactivity for CD 117, DOG1, Vimentin and CD 99. 6 months follow up post surgery with no recurrence.

Gastrointestinal Stromal Tumors of the Stomach: Is There Any Advantage of Robotic Resections? A Systematic Review and Meta-Analysis

Background: The role of robotic surgery for gastrointestinal stromal tumor (GIST) resection remains unclear. This systematic review and meta-analysis aimed to investigate the outcomes of robotic versus laparoscopic surgery in patients requiring surgery for gastric GISTs. Methods: MEDLINE, EMBASE, and the Cochrane databases were searched from inception to September 4, 2023. Two independent reviewers conducted a systematic review of the literature to select all types of analytic studies comparing robotic versus laparoscopic surgery for GISTs and reporting intraoperative, postoperative, and/or pathological outcomes. Results: Overall, 4 retrospective studies were selected, including a total of 264 patients, specifically 111 (42%) in the robotic and 153 (58%) in the laparoscopic group. Robotic surgery was associated with longer operating time (+42.46 min; 95% confidence interval [CI]: 9.34, 75.58; P=0.01; I2: 85%) and reduced use of mechanical staplers (odds ratio [OR]: 0.05; 95%CI: 0.02, 0.11; P<0.00001; I2: 92%;) compared with laparoscopy. Although nonsignificant, conversion to open surgery was less frequently reported for robotic surgery (2.7%) than laparoscopy (5.2%) (OR: 0.59; 95%CI: 0.17, 2.03; P=0.4; I2: 0%). No difference was found for postoperative and oncological outcomes. Conclusions: Robotic surgery for gastric GISTs provides similar intraoperative, postoperative, and pathological outcomes to laparoscopy, despite longer operative time.

Multifocal gastrointestinal stromal tumor with osseous metaplasia: a case report

BACKGROUND

Gastrointestinal stromal tumor is considered the most common mesenchymal neoplasm of the gastrointestinal tract. The majority of gastrointestinal stromal tumor cases are located in the stomach and usually affects older adults. Most of gastrointestinal stromal tumor cases are sporadic; however, few have a syndromic association, including Carney triad, Carney-Stratakis syndrome, familial gastrointestinal stromal tumor syndrome, and neurofibromatosis type 1.

CASE PRESENTATION

Herein, we report a rare case of a 54-year-old Middle-Eastern female with multifocal gastrointestinal stromal tumor mixed type (epithelioid and spindle cell type) with osseous metaplasia. Fluoresce in situ hybridization analysis of platelet-derived growth factor receptor alpha revealed deletion in 42% of the tumor cells studied. Interestingly, next generation sequencing revealed platelet-derived growth factor receptor alpha exon 12 mutation (p.Y555C) and exon 14 mutation (p.N659Y).

CONCLUSIONS

In conclusion, osseous metaplasia in GIST is a very rare event and only few cases are reported in the literature. The number of reported cases is inadequate to confirm the pathogenesis and the prognosis.

Risk Factors and Prognostic Analysis of Gastrointestinal Stromal Tumor Recurrence-Metastasis

Objective

Gastrointestinal stromal tumors (GISTs) are potential malignancies that occur in the digestive tract. This study aimed to investigate the risk factors and prognosis of recurrence and metastasis of gastrointestinal stromal tumor (GIST).

Methods

From January 2018 to December 2019, 422 patients with GIST who received surgery in the First Affiliated Hospital of Wenzhou Medical University were enrolled. Their clinical data were retrospectively analyzed, and their follow-ups were continued until March 31, 2022. Subsequently, univariate and multivariate Cox analyses, survival curves, and nomograms were adopted to explore the relationship between clinicopathological characteristics and recurrence or metastasis in patients with GIST.

Results

Univariate and multivariate Cox analysis exhibited that the prognosis of patients was affected by tumor rupture (P = 0.040), tumor location (P < 0.001), tumor diameter (P = 0.016), mitotic figures (P < 0.001), and risk grade (P < 0.009). The above variables were selected to create the nomogram for 3-year disease-free survival (DFS). The 3-year the ROC (receiver operating characteristic) curves of the nomogram were (0.878 95% confidence interval [CI]: 0.871-0.939).

Conclusion

Collectively, risk factors affecting postoperative recurrence or metastasis of GIST consist of primary site of tumors, tumor rupture, tumor diameter >10 cm, high-risk tumor classification, and mitotic figures ≥10 per 50 HPFs. And the application of nomogram may help physicians provide individualized diagnosis and treatment for patients with GISTs following surgical resection.

Minimally Invasive Approach to Gastric GISTs: Analysis of a Multicenter Robotic and Laparoscopic Experience with Literature Review

Simple Summary

Gastrointestinal stromal tumors (GISTs) represent about 1–3% of all gastrointestinal malignancies, of which 50–60% are gastric GISTs (GGs). To the date, surgery represents the best therapeutic option, and the robotic gastric surgery could gain an important role, overcoming many laparoscopic drawbacks. The aim of this study is to evaluate safety and effectiveness of minimally invasive surgery (MIS) for GGs, reporting 10-year experience of three different centers. We included a population of 81 patients who underwent MIS approaches (36 laparoscopy vs. 45 robotic surgery). Seventy-two (72) patients were enrolled in a follow-up program to evaluate the long-term oncological outcomes. Furthermore, we discussed some technical notes and also we analyzed the operative and peri-operative outcomes. In conclusion, our results suggest that the robotic approach might be a suitable treatment, especially for GISTs >5 cm, even located in unfavorable places, despite longer operative time and costs than laparoscopic approach.

Abstract

Background: Gastrointestinal stromal tumors (GISTs) are most frequently located in the stomach. In the setting of a multidisciplinary approach, surgery represents the best therapeutic option, consisting mainly in a wedge gastric resection. (1) Materials and methods: Between January 2010 to September 2020, 105 patients with a primary gastrointestinal stromal tumor (GISTs) located in the stomach, underwent surgery at three surgical units. (2) Results: A multi-institutional analysis of minimally invasive series including 81 cases (36 laparoscopic and 45 robotic) from 3 referral centers was performed. Males were 35 (43.2%), the average age was 66.64 years old. ASA score ≥3 was 6 (13.3%) in the RS and 4 (11.1%) in the LS and the average tumor size was 4.4 cm. Most of the procedures were wedge resections (N = 76; 93.8%) and the main operative time was 151 min in the RS and 97 min in the LS. Conversion was necessary in five cases (6.2%). (3) Conclusions: Minimal invasive approaches for gastric GISTs performed in selected patients and experienced centers are safe. A robotic approach represents a useful option, especially for GISTs that are more than 5 cm, even located in unfavorable places.

Recent advances in the management of gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is a rare but an important clinical entity seen in our clinical practice. It is the most common mesenchymal tumor of the gastrointestinal tract and most common malignancy of the small intestine. Although the exact prevalence of GIST is not known, the incidence of GIST has been increasing. GISTs arise from interstitial cells of Cajal. Most of the GISTs occur due to mutation in c-kit gene or platelet derived growth factor receptor alpha gene. 15% of GISTs do not have these mutations and they are called wild-type GISTs. Almost all GISTs express KIT receptor tyrosine kinase. Histologically, GISTs look like spindle cell tumors most of the time but they can be epitheloid or mixed type. The median size of GISTs varies from 2.7 cm to 8.9 cm. Clinically, patients with small GISTs remain asymptomatic but as the GIST size increases, patients present with various symptoms depending on the location of the GIST. Most of GISTs are located in the stomach or small bowel. Diagnosis is suspected on imaging and endoscopic studies, and confirmed by tissue acquisition with immunohistochemical staining. The aggressiveness of GISTs depends on the size, mitotic index and location. Surgical resection is the treatment of choice. But various endoscopic modalities of resection are increasingly being tried. Tyrosine kinase inhibitors are extremely useful in the management of large GISTs, unresectable GISTs and metastatic GISTs. Treatment options for metastatic GISTs also include radiotherapy, chemotherapy, hepatic artery embolization, chemoembolization and radiofrequency ablation.

Resection Combined with TKI Therapy for Resectable Liver Metastases of Gastrointestinal Stromal Tumours: Results from Three National Centres in China

OBJECTIVE

To investigate the differences in the efficacy of hepatic resection combined with tyrosine kinase inhibitor (TKI) therapy versus TKI therapy alone and the timing of the TKI therapy and hepatic resection for resectable liver metastases from gastrointestinal stromal tumours (GISTs).

METHODS

This was a retrospective review of 43 patients confirmed to have resectable liver metastases from GISTs who received TKI treatment alone or the therapy model of hepatic resection combined with TKIs and were admitted to one of 3 institutions between January 2006 and December 2017.

RESULTS

For all liver metastases patients, the 1-, 3- and 5-year survival rates were 97.67%, 88.98% and 66.46%, respectively. The median overall survival (OS) was 85 months. Patients who underwent hepatic resection combined with TKI therapy had a significantly better OS and a trend towards improved progression-free survival (PFS) than patients who received TKIs alone (P = 0.001, mOS 102 months versus 51 months; P = 0.077, mPFS 42 months versus 30 months). Hepatic resection combined with TKI therapy was the only prognostic factor for long-term survival in the multivariate analysis (HR = 0.198, 95% CI 0.048-0.813, P = 0.025). Compared with patients who underwent hepatic resection combined with postoperative TKIs only, patients who underwent hepatic resection combined with perioperative TKIs had a significantly better PFS (P = 0.032, mPFS 29 months versus 19 months) but did not have a significantly better OS (P = 0.662, mOS 92 months versus 102 months). Resection combined with perioperative TKI therapy was the only prognostic factor for PFS in the multivariate analysis (HR = 0.295, 95% CI 0.101-0.862, P = 0.026).

CONCLUSIONS

For patients with resectable liver metastases, hepatic resection combined with TKI therapy was more beneficial in terms of improving prognosis than TKIs alone. In terms of the timing of TKI therapy and hepatic resection, resection combined with perioperative TKIs may prolong PFS more than resection combined with postoperative TKIs only.

[Laparoscopic and robot-assisted procedures in patients with gastrointestinal stromal tumors (GIST) of stomach]

OBJECTIVE

To analyze the results of minimally invasive surgical procedures in patients with gastric GIST.

MATERIAL AND METHODS

The study included 30 patients aged 52.2±9.8 years. ASA grade II (44%), III (26%) and I (23%) were predominant. Lesion of stomach body was noted in 17 (56%) patients, antrum - in 8 (27%), fundus - in 2 (7%) and cardia - in 3 (10%) patients. GIST was located on the anterior wall of stomach in 56% of patients. Exophytic growth was observed in 16 (53%) patients, endophytic - in 12 (40%), transmural growth - in 2 (7%) cases. T2 grade of tumor was noted in 67% of cases (TNM 8). All patients underwent laparoscopic or robot-assisted ('daVinci Si') partial resection of the stomach.

RESULTS

Radical resection (R0) without injury of pseudocapsule of tumor was made in all patients. Laparoscopic procedures were performed in 25 (83%) patients, robot-assisted - in 5 (17%). Early postoperative complications (Clavien-Dindo II) were observed in 3 patients. Spindle cell structure of tumors (93%) with low mitotic activity (63%) prevailed. Tumor stage I was observed in 56% of patients. Patients with high mitotic tumor index (44%) were directed to targeted therapy. Recurrence and/or metastasis in long-term period were absent in 26 (87%) patients.

CONCLUSION

Laparoscopic surgery for gastric GIST is safe and characterized by the absence of significant postoperative complications and long-term recurrence-free period. The use of robotic surgical system is effective and justified for anatomically difficult localization of GIST.

Gastrointestinal Stromal Tumors of the Distal Gastrointestinal Tract

Gastrointestinal stromal tumors (GISTs) are rare in occurrence, but comprise the most common mesenchymal tumors of the gastrointestinal tract and affect between 15 and 20 individuals per million per year. Due to recent advancements in molecular classification of these tumors, medical therapy has provided improved outcomes to a historically surgically managed disease. This review article briefly discusses the molecular characteristics, medical and surgical therapies, and future of GIST management.

Primary extragastrointestinal stromal tumor arising in the vaginal wall: Significant clinicopathological characteristics of a rare aggressive soft tissue neoplasm

Gastrointestinal (GI) stromal tumor is the most common mesenchymal neoplasm of the GI tract but also occurs with a lower frequency in extragastrointestinal regions and is called extragastrointestinal stromal tumor (EGIST). We report an unusual case of EGIST presenting as a vaginal mass. A 41-year-old woman presented with a gradually enlarging vaginal mass for the last 2 years. Physical examination revealed an elliptical, non-tender mass about 7.5 cm × 7 cm in size in the posterior vaginal wall and was resected completely. Under histological examination, the tumor showed a spindle cell type with coagulation necrosis, hemorrhage and high mitotic count. Immunohistochemical analysis revealed tumor cells were positive for DOG1, CD117, CD34 and p53 protein. Ki-67 labeling was 8%. Genetic analysis showed a deletion of exon 11 of the c-kit gene at codons 557-558. EGISTs should be kept in mind in the differential diagnosis in patients presenting with solid mass of the vaginal wall.

Endoscopically Assisted Transumbilical Single-Incision Laparoscopic Gastric Resection for GIST Treatment

PURPOSE

Complete surgical resection with negative margins without lymphadenectomy is the treatment of choice for nonmetastatic Gastrointestinal Stromal Tumors (GISTs). Laparoscopic resection of gastric GISTs <5 cm is an acceptable and oncologically feasible, safe, and effective treatment. We present our experience of an endoscopically assisted minimally invasive transumbilical single-incision laparoscopic (SILS) technique for gastric GISTs resection.

METHODS

Four patients with small gastric GISTs ≤5 cm located on the greater curvature or the anterior wall were resected with SILS by using a lesion-lifting technique under the guidance of flexible gastroscopy.

RESULTS

The technique was feasible and safe and offered significant advantages in locating the tumor and controlling the resection margins. There were no major intraoperative or postoperative complications, conversions, or tumor ruptures. Pathology showed low-risk GISTs resected with disease-free margins without tumor rupture. No recurrences have been observed.

CONCLUSION

The endoscopically assisted SILS wedge gastrectomy is a feasible, safe, and advantageous technique for the treatment of the greater curvature or anterior wall gastric GISTs.

A comparison of the efficacy and safety of endoscopic full-thickness resection and laparoscopic-assisted surgery for small gastrointestinal stromal tumors

BACKGROUND AND AIM

Laparoscopic-assisted surgery (LAC) is an alternative to open surgery for gastrointestinal stromal tumors (GISTs). Endoscopic full-thickness resection (EFTR), a recently developed procedure, is increasingly used to resect GISTs originated from the muscularis propria. In this retrospective study, we aimed to compare EFTR with LAC as minimally invasive treatments for GISTs, especially those with a diameter <2 cm, originating from the muscularis propria. Moreover, we evaluated the clinical efficacy, safety, and feasibility of EFTR for GISTs.

METHODS

The study included 68 patients with GISTs originating from the muscularis propria (35 patients who underwent EFTR, and 33 who underwent LAC) who were treated at the Affiliated Hospital of Guangdong Medical University (Zhanjiang, China) between January 2011 and December 2013. The therapeutic outcomes of EFTR and LAC were reviewed retrospectively.

RESULTS

In the EFTR group, the mean tumor size was 13 ± 5 mm, the mean procedure time was 91 ± 63 min, and the complete resection rate was 100 %. There were 35 "artificial" perforations and four cases of intraoperative bleeding; all complications were successfully managed endoscopically without emergency surgery. In the LAC group, the mean tumor size was 16 ± 4 mm, the mean operation time was 155 ± 37 min, and complications included three wound infections and one anastomotic leakage.

CONCLUSIONS

EFTR was associated with a lower complication rate than LAC, with favorable en bloc and sufficient tumor tissue for histological diagnosis. EFTR seems to be an efficacious, relatively safe, and minimally invasive treatment for GISTs and could replace LAC surgical resection in cases where the tumor is smaller than 2 cm in diameter.

Profile of patients with gastrointestinal stromal tumors (GIST)

Background

There is an improvement on the GIST treatment in last decade due to biomolecular research and adjuvant therapy with tyrosine kinases inibitors. However, both modalities of treatment rarely are available in Brazilian public hospital.

Aim

Evaluate GIST patients profile in public oncologic hospital.

Methods

A retrospective study was made on patients with GIST diagnosed and treated between 2001 and 2013.

Results

Sixty-nine patients were included, mean age 59 years with slight predominance in females (51%). The main symptom was abdominal pain associated with incidental imaging finding. The occurrence of other associated neoplasm was in 28.8% of cases. The positivity of CD117 was 97.1%. The most frequent location was the stomach in 55.1% of cases. The R0 resection was possible in 63.8% and the recurrence rate was 20.3 %, with liver and peritoneum the main affected sites. Overall survival in the whole sample was 71%. Free survival rate of disease was 64%. The use of imatinib was limited to patients with residual disease (unresectable disease, R2 and R1 resection), metastatic disease or recurrence.

Conclusion

In order to improve GIST treatment is necessary to add the biomolecular analysis to risk stratification. However, for this to occur, incentive in biomolecular research is required, to increase the possibility of patient survival.

Primary mesenteric gastrointestinal stromal tumour

Primary mesenteric gastrointestinal stromal tumours (GISTs) are rare tumours and can be included as a differential for an expanding intraabdominal mass. We present the case, in our institution, of a 72-year-old male who presented with non-specific symptoms and was diagnosed with a primary mesenteric GIST following resection. We report his follow-up and discuss the current theories as to the origins of these rare tumours and current treatment modalities.

Endoscopy dissection of small stromal tumors emerged from the muscularis propria in the upper gastrointestinal tract: Preliminary study

AIM: To investigate the feasibility and safety of the treatment of an upper gastrointestinal (GI) submucosal tumor with endoscopic submucosal dissection (ESD).

METHODS: A total of 20 patients with esophageal and gastric submucosal tumors emerged from the muscular layer identified by endoscopic ultrasonography were collected from January 2009 to June 2010. Extramural or dumbbell-like lesions were excluded by an enhanced computerized tomography (CT) scan. All patients had intravenous anesthesia with propofol and then underwent the ESD procedure to resect these submucosal tumors. The incision was closed by clips as much as possible to decrease complications, such as bleeding or perforation, after resection of the tumor. All the specimens were collected and evaluated by hematoxylin, eosin and immunohistochemical staining, with antibodies against CD117, CD34, desmin, α-smooth muscle actin and vimentin to identify the characteristics of the tumors. Fletch’s criteria was used to evaluate the risk of gastrointestinal stromal tumors (GISTs). All patients underwent a follow-up endoscopy at 3, 6 and 12 mo and CT scan at 6 and 12 mo.

RESULTS: The study group consisted of 5 men and 15 women aged 45-73 years, with a mean age of 60.2 years. Three tumors were located in the esophagus, 9 in the gastric corpus, 4 in the gastric fundus, 3 lesions in the gastric antrum and 1 in the gastric angulus. Apart from the one case in the gastric angulus which was abandoned due to being deeply located in the serosa, 94.7% (18/19) achieved complete gross dissection by ESD with operation duration of 60.52 ± 30.32 min. The average maximum diameter of tumor was 14.8 ± 7.6 mm, with a range of 6 to 30 mm, and another lesion was ligated by an endoscopic ligator after most of the lesion was dissected. After pathological and immunohistochemical analysis, 12 tumors were identified as a GI stromal tumor and 6 were leiomyoma. Mitotic count of all 12 GIST lesions was fewer than 5 per 50 HPF and all lesions were at very low (9/12, 75.0%) or low risk (3/12, 25.0%) according to Fletch’s criteria. Procedure complications mainly included perforation and GI bleeding; perforation occurred in 1 patient and conservative treatment succeeded by a suturing clip and no post-operative GI bleeding occurred. All patients were followed up for 6.5 ± 1.8 mo (range, 3-12 mo) by endoscopy and abdominal CT. Local recurrence and metastasis did not occur in any patient.

CONCLUSION: ESD shows promise as a safe and feasible technique to resect esophageal and gastric submucosal tumors and the incidence of complications was very low. Clinical studies with more subjects and longer follow-up are needed to confirm its treatment value.

[A case of multiple gastrointestinal stromal tumor of the jejunum which was diagnosed by capsule endoscopy]

More than 90% cases of chronic gastrointestinal bleeding can be diagnosed by upper endoscopy and/or colonoscopy, and therefore, obscure gastrointestinal bleeding has been defined as bleeding of unknown origin that persists after these conventional endoscopic evaluation. Gastrointestinal stromal tumors (GISTs) are rare tumors, but the most common form of mesenchymal tumors of the gastrointestinal tract. Small bowel is the second most common primary site for GISTs, and accounts for 2-10% of chronic bleeding sites. GISTs usually present as a sporadic and solitary tumor, and a minority of the cases of multiple GISTs are discovered as forms of hereditary or idiopathic tumor syndromes. Small bowel tumor has been difficult to diagnose because of absence of accurate and proper diagnostic tools. Recently developed wireless capsule endoscopy helps in the diagnostic work-up of small bowel diseases. We report a case of multiple jejunal GISTs presenting melena in a 39-year-old male, which was diagnosed with wireless capsule endoscopy.

Survivin expression and its potential clinical significance in gastrointestinal stromal sarcoma

This study was designed to determine the level of survivin expression and its clinical significance as a prognostic factor in gastrointestinal stromal sarcoma (GIST). Twenty patients (12 males and 8 females) ranging in age from 25 to 72, with a median age of 53 were evaluated. Failure of TKI treatment was higher in the survivin-positive group (p=0.06). The rate of metastasis was significantly higher in the survivin positive group vs. the negative group (80% vs. 30%, p=0.18). The median overall survival (OS) time was 114 (range 29-199)months, and the median disease-free survival (DFS) time was 88 (range 40-135) months. The median progression-free survival (PFS) time was 40 (range 24-55) months. Further, a comparison of patients with survivin positive versus negative tumors, revealed no significant difference for OS, DFS, and PFS (p=0.45, p=0.19, p=0.55, respectively), number of mitoses in 50 HPF (p=0.14), and tumor size (p=0.94). In conclusion, survivin was highly expressed in GISTs, although we found no correlation between survivin expression and PFS, DFS and OS, survivin may be a predictive marker in GISTs for disease progression. We believe that additional studies are warranted to determine the clinical significance of survivin expression as a prognostic or predictive marker in patients with GIST.

Extragastrointestinal Stromal Tumor (EGIST) in the abdominal wall: Case report and literature review

INTRODUCTION

Gastro Intestinal Stromal Tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract (GI). GIST that arises primarily outside the GI tract is termed Extragastrointestinal Stromal Tumor (EGIST). To the best of our knowledge, few cases of EGIST in the abdominal wall were reported.

PRESENTATION OF CASE

We present a rare case of EGIST in the abdominal wall of a 57 year-old female patient. The asymptomatic tumor was located in the superior aspect of the left rectus abdominis muscle, measured 5.4 × cm 5.3 × cm 6.9 cm and was well circumscribed. Histological examination showed an epithelioid cell morphology. The mitotic count was 7/50 HPFs. Immunohistochemistry showed diffuse strong CD117 positivity, focal positivity for S100. The tumor was excised and the margins were free of malignancy. The patient was doing well postoperatively and was discharged on STI-571 regimen.

DISCUSSION

Although GIST is the most common mesenchymal tumor of the gastrointestinal tract, a case with EGIST in the abdominal wall is rare. Positive immunohistochemical staining for CD117 is a defining feature of GISTs. A great percentage of EGISTs represent a metastasis from a primary GIST. In our case, the clinical and diagnostic work-up have been proved it to be an EGIST.

CONCLUSION

The existing data on EGIST is insufficient to make a final conclusion regarding the malignant potential and clinicopathological factors of EGISTs that determine patient prognosis. Thus a follow-up for a long period is required. EGISTs should be kept in mind in the differential diagnosis for patients presenting with solid mass of the abdominal wall.

Gastrointestinal stromal tumors: report of an audit and review of the literature

Gastrointestinal stromal tumors (GISTs), tumors characterized by c-KIT mutations, are the most frequent mesenchymal tumors of the digestive tract. The stomach is the most commonly involved site. Localization, size and mitotic rate are reliable predictors of survival and the two milestones of GISTs treatment are surgery and imatinib. This article is aimed to report the data of an audit, carried out on the morphological and clinical aspects of the disease and to review the present knowledge on GISTs. A total of 172 patients with GISTs (M : F=1 : 1; mean age 65 years) were recruited. The stomach was the most frequently involved site. In 50% of the cases the tumor was smaller than 5 cm, whereas major symptoms were observed in 43% of the cases. Predictors of progressive disease were present only in a small percentage of cases but the disease was in the metastatic phase in over 25% of the cases at diagnosis. Familial aggregation was rare but a consistent share of the patients (21%) had other synchronous or metachronous cancers. The most frequent mutations were in-frame deletions and point mutations of c-KIT exon 11. This report confirms in part the available data on GIST in a consecutive series of patients recruited in Italy and shows that only large collaborative multicenter studies provide data sound enough to enable making reasonable clinical and therapeutic choices, and suggests that, as a measure of secondary prevention, a diagnostic definition should be obtained in all submucosal lesions of the GI tract and that GIST patients should be screened for second tumors.

Clinical significance of performing 18F-FDG PET on patients with gastrointestinal stromal tumors: a summary of a Japanese multicenter study

OBJECTIVE

The aim of this study is to evaluate the clinical significance of performing (18)F-fluorodeoxyglucose (FDG) positron-emission tomography (PET) on patients with gastrointestinal stromal tumors (GISTs).

METHODS

The patient samples for this study were provided by seven PET institutions in Japan. Forty-one patients with pathologically proved GISTs, 24 men and 17 women (mean age 60.3 years, range 26-81 years) were enrolled in this study. Final diagnosis was based on the follow-up imaging at least 3 months after the PET scan or histopathological examinations.

RESULTS

There were eight preoperative cases and 33 follow-up cases in our series. Preoperative cases showed that the sites of primary tumor were the stomach (5 cases, 62.5%), and small intestine (3 cases, 37.5%). One stomach lesion and one small intestine lesion showed negative findings. In follow-up cases, there were 18 PET-negative cases. Among them, two cases were considered as false negative by follow-up imaging. On the other hand, 15 cases showed positive findings at 23 lesions. Most PET-positive cases were considered as true positive except for one false-positive case, who later received surgery and was diagnosed as leiomyoma histopathologically. In 14 cases, PET findings were considered to provide additional information to conventional imaging. In eight cases among them, PET findings were considered to have influenced the decision-making of therapeutic plans.

CONCLUSION

Our data suggest that FDG PET has an incremental value over conventional imaging for the diagnostic and therapeutic management of patients with GISTs in Japan as reported worldwide, and supports its introduction as a routine diagnostic tool for patients with GISTs.

Diagnosis and management of GI stromal tumors by EUS-FNA: a survey of opinions and practices of endosonographers

BACKGROUND

There is no consensus regarding the best management strategy for diagnosing and treating GI stromal tumors (GISTs).

OBJECTIVE

Our purpose was to examine the practice patterns of endosonographers in diagnosing and managing GISTs, particularly features of GISTs suggestive of malignancy, features that prompt surgical referral, and surveillance patterns.

DESIGN

An invitation to complete an online survey was e-mailed to all 413 members of the American Society for Gastrointestinal Endoscopy EUS Special Interest Group.

RESULTS

A total of 134 (32%) members responded; 59% of respondents use EUS features combined with FNA findings to diagnose GIST, and 89% consider a c-kit-positive stain on FNA most suggestive of GIST. However, 60% would diagnose GIST when cytologic samples are insufficient for diagnosis, and 40% would diagnose GIST if cytologic samples are sufficient but c-kit is negative. A total of 92% use size as the main criterion to distinguish benign from malignant GISTs, and 90% refer lesions >5 cm for surgery. For lesions not resected, 70% survey annually, 19% less than annually, 10% more than annually, and 1% do not survey.

LIMITATIONS

The opinions of the respondents do not necessarily reflect the opinions and practices of endosonographers nationwide. There are inherent limitations to an online multiple-choice survey, including low response rates.

CONCLUSIONS

There are substantial practice variations in diagnosing, resecting, and surveying GISTs. A majority of our survey respondents have made the diagnosis of GIST without FNA confirmation. Size >5 cm is the feature used most to predict malignancy and to prompt surgical referral. Surveillance practices for unresected GISTs are variable. Evidence is needed to establish practice guidelines in this area.

Prevalence and Management of Gastrointestinal Stromal Tumors

The prevalence and characteristics of patients with confirmed gastrointestinal stromal tumor (GIST) in a community hospital over a 6-year period are described. Our objective was to communicate our experience managing this rare tumor of the gastrointestinal tract. A retrospective chart review was performed. Patients were selected based on International Classification of Diseases, 9th Revision codes in correlation with their respective confirmational pathology. Patients with a diagnosis of GIST, cells of Cajal tumor, and/or different varieties of gastrointestinal sarcoma were included in this study. These tumors had to have a positive C-kit on immunohistochemistry. Demographic and clinical data were collected from medical records as well as pathology reports. Follow up from attendings’ office records and telephone interviews complemented our data. A total of 61 patients was identified in our institution (averaging 10 patients per year). Females represented 63 per cent of our series. The average ages were 70.2 ± 19.1 years for females and 59.4 ± 13.5 years for males ( P < 0.01). The most common clinical presentation was an intra-abdominal nonobstructing mass followed by an endoscopically detected mass or incidental tumors found during unrelated surgery. Surgical emergencies such as acute abdomen and gastrointestinal bleed were rare. Over half of these tumors were located in the stomach. Other sites were the small intestine, colon, esophagus, and rectal–vaginal septum. Opened surgical resection was performed in two-thirds of treated cases, whereas laparoscopic resection was done in the remainder. Only 18 per cent of these tumors were considered benign, whereas 35 per cent were considered to have some malignant potential and 47 per cent were of undetermined potential. In surgically resected tumors, we found a 42 per cent recurrence rate with a median average time of recurrence of 22 months. Pathologic grading and type of surgery were not predictors of rate and timing of recurrence. However, the disease tended to be more aggressive in white males and age older than 70 years. Imatinib was used mainly in attempts to downstage, control recurrent disease, and make surgery possible. With the improvement of immunohistochemical techniques, the diagnosis of GIST is increasing. Preoperative diagnosis is highly uncertain and dependent on clinical suspicion. Surgical resection is still the main form of curative therapy. Our experience is similar to large-volume centers. GIST, once recognized, can be treated in community hospitals without compromise of their care.

A systematic review on the clinical diagnosis of gastrointestinal stromal tumors

BACKGROUND

The aim of this work was to assess the prevalence of symptoms of gastrointestinal stromal tumors (GISTs) and the diagnostic yield of clinical procedures for its diagnosis.

METHODS

Medical databases were consulted between 1998 and 2006 for potentially relevant publications. All studies dealing with the clinical presentation of GIST and related diagnostic procedures were included. Two researchers worked independently on the study selection, quality assessment, data extraction, and analysis phases of the study.

RESULTS

Forty-six observational studies were included with a total of 4,534 patients. Gastrointestinal bleeding was the most common clinical presentation. Twenty studies provided adequate information on the diagnostic yield of various procedures. The pooled diagnostic yield of endoscopy + mucosal biopsy and of intestinal contrast radiography was 33.8% (0-100%) and 35.1% (11-100%), respectively, while that of EUS and that of EUS-FNA was 68.7% (40-100%) and 84.0% (73.8-100%), respectively. Abdominal CT scan and MRI had similar pooled diagnostic yields: 73.6% (34.8-100%), and 91.7% (75-100%), respectively.

CONCLUSION

Endoscopy + mucosal biopsy should be reserved to patients with gastrointestinal bleeding. EUS-FNA provides direct visualization of the neoplasm and adequate samples for molecular diagnosis. EUS, abdominal CT and MRI may be considered valid alternatives whenever EUS-FNA is unavailable or a cytological diagnosis is unnecessary.

Therapeutic consequences from molecular biology for gastrointestinal stromal tumor patients affected by neurofibromatosis type 1

PURPOSE

Patients affected by neurofibromatosis type 1 (NF-1) have an increased risk of developing gastrointestinal stromal tumors (GIST). NF-1-associated GISTs are usually wild type for c-KIT and platelet-derived growth factor receptor-alpha (PDGFR-alpha) mutations and harbor a different oncogenic molecular mechanism. The lack of data on imatinib activity raises the question whether to enroll these patients in clinical trials. We analyzed a large series of NF-1 related GISTs to discuss the therapeutic implications.

MATERIALS AND METHODS

Clinical, pathologic (IHC to CD34, S100, bcl-2, PDGFRA), and molecular features (exons 9, 11, 13, 14, 17 in c-kit and exons 12, 14, 18 in PDGFRA) of 28 patients were analyzed.

RESULTS

The most common site of primary lesions was the small bowel (75%). Twelve patients (43%) had multiple tumors. Most tumors belonged to the high (30.5%) or intermediate risk group for malignant behavior (39%). Three patients developed peritoneal and liver metastases; another four had peritoneal spread only. All tumors were immunohistochemically strongly positive for CD117. Three primary KIT/PDGFRA activating mutations were found. Three metastatic patients treated with imatinib experienced progression, and only one had temporary stable disease. Median survival after starting treatment with imatinib was 21 months.

CONCLUSIONS

This study is the largest series available and confirms that KIT/PDGFRA mutations in NF-1-associated GISTs are sporadic. Prognosis of metastatic tumors is poor, and imatinib response rate is low. Patients with NF-1-GIST of high or intermediate risk should not be eligible for adjuvant trials of imatinib. Imatinib should not be used in a neoadjuvant intent in these patients, and molecular analysis of activating mutations is strongly recommended.

Unusual combination of paraneoplastic manifestations in a patient with metastatic gastrointestinal stromal tumor (GIST)

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Activating mutations in tyrosine kinase receptors KIT or platelet-derived growth factor receptor alpha (PDGFRA) are the main mechanisms causing the disease. Patients generally present with non-specific symptoms, while a number of tumors are discovered incidentally and may be metastatic at the time of diagnosis. Aggressive GISTs have a defined pattern of metastasis to the liver or throughout the abdomen, or both. Though GISTs rarely present systemic or isolated paraneoplastic reactions, a few cases have been reported in the literature. We present the case of a 54-year-old patient with metastatic GIST at diagnosis and the emergence of paraneoplastic manifestations during follow-up.

Long-term follow-up in 54 surgically treated patients with gastrointestinal stromal tumours

BACKGROUND

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the alimentary tract. Since these tumours are rather resistant to radiation and conventional chemotherapy, prognosis may be poor. Imatinib, a KIT tyrosine kinase inhibitor, has been shown to have dramatic antitumour effects on GISTs; however, surgical en bloc resection of the tumour with free resection margins remains still the first option for cure.

MATERIALS AND METHODS

Here, we present a retrospective study with 54 consecutive GIST patients who were treated surgically at our University Hospital between 1993 and 2005 and were followed up at 5 and 10 years.

RESULTS

The disease-specific survival rate was 94% at 1 year, 91% at 3 years, 76% at 5 years, and 72% at 10 years. In univariate analysis, tumour size, mitotic rate, morphology, and necrosis predicted survival in patients with negative margins. Age, sex, and symptoms did not influence outcome.

CONCLUSION

GISTs have a high incidence of associated secondary malignancies which may have a significant influence on prognosis and outcome. Patients with R0 resections had a significantly better survival rate of 86% at 5 years and of 81% at 10 years than those with R1 and R2 resections (21% and 0%).

Laparoscopic gastric resection for gastrointestinal stromal tumors

BACKGROUND

This study aimed to review clinical outcomes for patients selected to undergo laparoscopic resection for gastrointestinal stromal tumor (GIST) of the stomach.

METHODS

All 112 laparoscopic gastric resections performed from February 1995 to March 2007 were reviewed. Pre- and postoperative variables were analyzed, and data are given as mean +/- standard deviation.

RESULTS

Laparoscopic gastric resection was attempted for 63 GIST in 61 patients (31 men and 30 women) with a mean age was 59.1 +/- 19 years. The tumors were located at the fundus (n = 19), antrum (n = 18), body (n = 17), gastroesophageal junction/cardia (n = 7), and pylorus (n = 2). Common presentations were upper gastrointestinal bleed (n = 29) and incidental finding on esophagogastroduodenoscopy (n = 17). The laparoscopic procedures performed were partial gastrectomy (n = 52), antrectomy (n = 4), esophagogastrectomy (n = 3), and endoscopically assisted and/or transgastric resection (n = 3). There was one conversion to open procedure for control of bleeding from the spleen. The mean tumor size was 3.8 +/- 1.8 cm. Negative surgical margins were achieved in all but one case. The mean operative time was 151.9 +/- 67.3 min, and the mean estimated blood loss was 97.4 +/- 200.7 ml. A regular diet was resumed at a mean of 2.9 +/- 1.6 days, and the mean length of hospital stay was 3.9 +/- 2.2 days. The perioperative complication rate was 16.4% including deep vein thrombosis postoperative bleed, anastomotic stricture, and incisional hernia. One mortality occurred, due to respiratory failure. The GISTs included 48 rated as low risk, six rated as intermediate risk, and nine rated as high malignant potential. At a mean follow-up period of 15 +/- 21.8 months (range, 0-103 months), three of nine patients with high malignant potential GIST experienced, respectively, metastatic disease to the liver, liver and lung, and peritoneum. At this writing, all the other patients are disease free.

CONCLUSIONS

Laparoscopic gastric resection for GIST is a feasible option. Adequate oncologic resection was achieved with 98.4% of patients chosen for laparoscopic resection. Resection margin positivity and recurrence rates are low after laparoscopic approaches for appropriately selected patients with GIST, demonstrating favorable characteristics.

Tumor estromal gastrointestinal: análise de fatores relacionados ao prognóstico

OBJETIVO: estudar os critérios morfológicos e imunoistoquímicos relacionados ao prognóstico dos tumores estromais gastrointestinais. MÉTODOS: o estudo foi retrospectivo de 42 casos de tumor estromal gastrointestinal (GIST). Vinte e cinco casos foram obtidos no arquivo do Serviço de Anatomia Patológica do Hospital Universitário Gaffrée e Guinle e os outros dezessete, do Serviço de Anatomia Patológica do Hospital Universitário Clementino Fraga Filho. RESULTADOS: de acordo com a análise univariada os tumores maiores que 5 cm, com número de mitoses maior que 5/50 CGA, presença de necrose, de alto risco, revelaram significância em relação a redução da sobrevida (p= 0,017, 0,010, 0,001 e 0,016, respectivamente). Os outros fatores analisados (subtipo histológico, topografia e imunofenótipo) não mostraram significância. CONCLUSÃO: os resultados confirmam a utilidade do grau de risco, do tamanho tumoral, do índice mitótico e da necrose como fatores preditores do comportamento biológico dos tumores estromais gastrointestinais.