Updates on the management of gastrointestinal stromal tumors

Extremely Rare Synchronous Primary Neoplasms of Meckel's Diverticulum and Colon: a Report of Three Cases

Synchronous primary neoplasms of Meckel's diverticulum and colon malignancies are rarely reported in the literature. We present three patients with synchronous primary neoplasms of Meckel's diverticulum and colon malignancies. All tumors located in Meckel's diverticulum were incidentally found at laparotomy and the definitive diagnosis was made with microscopic examination of surgical specimens. Synchronous primary neoplasms of Meckel's diverticulum and colon malignancies are rarely encountered. Moreover, this is the first case of synchronous colon cancer and pancreatic intraepithelial neoplasia (PanIN) arising from pancreatic heterotopia within Meckel's diverticulum. The diagnosis of Meckel's diverticulum should be kept in mind in patients who underwent laparotomy for any reason; when found incidentally at laparotomy, it should be carefully examined for any suspicious abnormality and surgery should be considered that it can be performed without any problems.

Emerging Targeted Therapeutic Strategies to Overcome Imatinib Resistance of Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common malignant mesenchymal neoplasms of the gastrointestinal tract. The gold standard for the diagnosis of GISTs is morphologic analysis with an immunohistochemical evaluation plus genomic profiling to assess the mutational status of lesions. The majority of GISTs are driven by gain-of-function mutations in the proto-oncogene c-KIT encoding the tyrosine kinase receptor (TKR) known as KIT and in the platelet-derived growth factor-alpha receptor (PDGFRA) genes. Approved therapeutics are orally available as tyrosine kinase inhibitors (TKIs) targeting KIT and/or PDGFRA oncogenic activation. Among these, imatinib has changed the management of patients with unresectable or metastatic GISTs, improving their survival time and delaying disease progression. Nevertheless, the majority of patients with GISTs experience disease progression after 2-3 years of imatinib therapy due to the development of secondary KIT mutations. Today, based on the identification of new driving oncogenic mutations, targeted therapy and precision medicine are regarded as the new frontiers for GISTs. This article reviews the most important mutations in GISTs and highlights their importance in the current understanding and treatment options of GISTs, with an emphasis on the most recent clinical trials.

A case of jejunal GIST revealed by hematemesis: Unusual situation

Introduction

Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal (GI) tract, which can occur in majorly stomach, and rarely in the small intestine, rectum, and large intestine. We report a jejunal GIST presented with massive hematemesis in the current study.

Case presentation

A 39-years-old male, without any underlying history, was presented to our center with the complaint of massive hematemesis. Given the unstable hemodynamics of the patient, an upper GI endoscopy was requested, associated with a large amount of blood in the duodenal bulb without any sign of bleeding. The patient was sent to the operation room, and after laparotomy, a mass was seen in the jejunum, revealed as GIST after pathological study.

Discussion

Small-intestine-related etiologies are rare conditions related to upper GI bleeding (UGIB). Jejunal GIST usually manifests as asymptomatic subepithelial mass and is associated with abdominal discomfort or GI bleeding. Sudden unset bleeding is a rare manifestation of jejunal GIST, but it can be associated with the emergency outcome and may need emergency intervention.

Conclusion

UGIB can occur in jejunal GIST, which should be considered in the management of UGIB.

•

Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal (GI) tract.

•

GISTs are rarely found in the small intestine, compatible with abdominal discomfort.

•

Jejunal GISTs usually manifest as intestinal obstruction and abdominal pain.

•

Massive hematemesis is rare in jejunal GISTs and should be consider in the management of upper GI bleeding.

Value of 18F-FDG PET/CT for differentiating diagnosis between malignant and benign primary gastric gastrointestinal mesenchymal tumors: a single-center retrospective study

BACKGROUND

Malignant primary gastric gastrointestinal stromal tumors (gGISTs) without treatment with imatinib are prone to bleeding and peritoneum implantation during operation. Therefore, preoperative assessment of the malignant potential of gGIST is essential. The use of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) combined with computed tomography (PET/CT) as a non-invasive tool for diagnosis, staging and prognosis evaluation in oncology, may also be useful for gGISTs. In the present study, we analyzed the value of 18F-FDG PET-CT in assessing the malignant potential of gGISTs before treatment.

METHODS

Patients who were diagnosed with gGIST by pathology and underwent 18F-FDG PET/CT at the same time were collected. The clinicopathological features of 26 patients with gGISTs were retrospectively analyzed at last. The gGIST risk classification was graded according to the US National Institutes of Health (NIH) GIST risk classification criteria [2008]. Lesions were classified as malignant group (moderate- or high-risk category) and benign group (low- or very low-risk category) according to pathology. The relationship between the maximal standard uptake value (SUVmax) and GIST risk category, tumor diameter, Ki-67 index, and mitotic count was analyzed. The cut-off level of SUVmax for the diagnosis of malignant gGIST with the highest sensitivity was calculated based on the receiver-operating characteristic (ROC) curve.

RESULTS

The SUVmax, tumor diameter, Ki-67 index, and mitotic count of the 26 gGIST patients were 5.90±4.49, 7.40±4.92 cm, 7.62%±11.76%, (5.96±3.19)/50 high-power field (HPF), respectively. SUVmax was significantly correlated with GIST risk category, Ki-67 index, and mitotic count (r=0.855, 0.860, and 0.690, all P<0.01) but not with tumor diameter (r=0.383, P=0.054). The SUVmax of gGIST was 7.00±4.57 in the malignant group (moderate or high NIH risk category in 20 patients), which was significantly different from that (2.25±0.77) in the benign group (low or extremely low NIH risk category in 6 patients) (t=4.566, P<0.01). ROC curve analysis showed that a SUVmax cut-off of 2.60 was most sensitive for predicting malignant gGIST. When the area under the curve was 0.967, the sensitivity was 100% and the specificity was 83.3%.

CONCLUSIONS

SUVmax may be used as a complementary indicator for predicting the malignant potential of gGISTs before treatment.

Diagnosing gastrointestinal stromal tumors: The utility of fine-needle aspiration cytology versus biopsy

Background

Gastrointestinal stromal tumors (GIST) are mesenchymal tumors in the intestinal tract originating from a precursor to the interstitial cells of Cajal, which plays a role in gastric motility. The preoperative diagnosis of GIST may be very important for the surgical approach or the need for neoadjuvant treatment and is often done in conjunction with molecular testing.

Design

GISTs diagnosed in Stockholm between 1999 and 2019 with biopsy and/or fine‐needle aspiration (FNA) material were included. Clinical and tumor characteristics, as well as sample representability, ancillary techniques, diagnostic accuracy, and time to diagnosis, were categorized and compared.

Results

We identified 460 diagnostic samples from 347 patients, consisting of 212 biopsies and 248 FNAs. FNA cytology had a significantly (p < 0.05) better sample representability (92% vs. 77%), diagnostic accuracy (84% vs. 76%), and shorter time to diagnosis (4.5 vs. 12.3 days on average) in comparison with biopsies. In addition, ancillary techniques such as immunochemistry and molecular analysis for KIT and PDGFRA mutations could satisfactorily be performed on FNA materials.

Conclusions

There are advantages to both biopsy and FNA cytology in diagnosing GISTs. While the significantly shorter time to diagnosis for FNA cytology can be due to institutional differences, its many strengths make it both an accurate and time‐efficient method for preoperative diagnosis of GIST.

Gastrointestinal Stromal Tumor (GIST) from esophagus to anorectum - diagnosis, response evaluation and surveillance on computed tomography (CT) scan

Gastrointestinal stromal tumor (GIST) are the most common non epithelial tumor of the gastrointestinal (GI) tract. They arise from interstitial cells of Cajal present in the myenteric plexus. They can also arise outside the GI tract from mesentery, retro peritoneum and omentum. With the advent of new targeted molecular therapy c- tyrosine kinase inhibitor (Imatinib), it has become important to differentiate between response and pseudo-progression of the disease as response evaluation criteria for GIST are different from Response Evaluation Criteria in Solid Tumors (RECIST). Purpose of this pictorial essay is to enumerate the characteristic CT features of GIST, and discuss atypical features and response evaluation criteria.

Characteristics of Gastrointestinal Stromal Tumors incidentally discovered during abdominal surgery

BACKGROUND

Gastrointestinal Stromal Tumors (GISTs) are rare sarcomas with 5000 new cases arising in the United States each year. Despite their low incidence, general surgeons should be familiar with GISTs since a quarter of these neoplasms are encountered incidentally.

METHODS

A retrospective medical records review was conducted to create a database of all GISTs resected from January 2005 to May 2019. We isolated patients who had incidental discovery of GISTs intraoperatively or within final pathology. Characteristics of patient (Age, gender), index procedure (malignant vs. benign, elective vs. emergent) and tumor (location, size and mitotic rate) were analyzed.

RESULTS

A total 48 patients were incidentally discovered to have a GIST excised during index operation. The mean age of these patients was 62 years, with 27 females and 21 males. The primary location of tumors in descending frequency was stomach (30), small bowel (15), colon/rectum (2) and esophagus (1). The average size of all tumors was 1.2 cm, with the average size of the stomach, small bowel, colon/rectum and esophagus at 0.9 cm, 1.7 cm, 0.9 cm and 0.3 cm respectively. Mitotic rate was less than 5 mitosis per 50 HPF in 96% of patients. Incidental tumors were identified during both bariatric (13) and non-bariatric stomach surgery (8), colorectal surgery (14), hernia repair (4), ampullary/pancreatic surgery (5), esophageal surgery (2) liver surgery (1) and uterine surgery (1). Most incidental-GISTs were identified during elective surgery (81%, 39). Finally, 15 of the tumors were identified during surgery for other malignancies.

CONCLUSIONS

One quarter (25%) of the GISTs encountered at our academic community cancer center over a 15-year period were discovered incidentally. These tumors had less malignant characteristics overall and were likely cured with surgical resection.

Gastrointestinal stromal tumors: relationship between preoperative CT features and pathologic risk stratification

OBJECTIVE

To investigate a relationship between contrast-enhanced computed tomography (CECT) features of gastrointestinal stromal tumors (GISTs) and risk of relapse according to Miettinen stratified risk classifications.

METHODS

After ethical committee approval, a retrospective analysis was conducted on the preoperative CECT of patients with pathologically proven GIST undergoing surgery between June 2009 and December 2019. Chi-square analysis was used to evaluate the correlation between Miettinen stratified risk categories and the following imaging features: tumor size and location, growth pattern, margins, type and degree of contrast enhancement, presence of calcifications, necrosis, signs of ulceration/fistulation, internal hemorrhagic foci, enlarged feeding or draining vessels (EFDV), ascites, peritoneal implants, lymphadenopathy, or metastasis.

RESULTS

A total of 54 patients (mean age 65 ± 11, 29 men) were included in the study with a total of 56 GISTs. Necrosis, ulceration/fistulation, hemorrhage, margins, enlarged vessels, type of contrast enhancement, and metastasis turned out to be associated with Miettinen risk categories (p < 0.005). Logistic regression analysis identified the presence of necrosis and EFDV as predictors of pathologic risk of relapse (overall accuracy of 89.3%).

CONCLUSION

Preoperative CECT may be helpful in predicting pathologic risk categories of GISTs, as determined by the Miettinen classification system.

Gastrointestinal Stromal Tumors (GISTs): Novel Therapeutic Strategies with Immunotherapy and Small Molecules

Gastrointestinal stromal tumors (GISTs) are the most common types of malignant mesenchymal tumors in the gastrointestinal tract, with an estimated incidence of 1.5/100.000 per year and 1–2% of gastrointestinal neoplasms. About 75–80% of patients have mutations in the KIT gene in exons 9, 11, 13, 14, 17, and 5–10% of patients have mutations in the platelet-derived growth factor receptor a (PDGFRA) gene in exons 12, 14, 18. Moreover, 10–15% of patients have no mutations and are classified as wild type GIST. The treatment for metastatic or unresectable GISTs includes imatinib, sunitinib, and regorafenib. So far, GIST therapies have raised great expectations and offered patients a better quality of life, but increased pharmacological resistance to tyrosine kinase inhibitors is often observed. New treatment options have emerged, with ripretinib, avapritinib, and cabozantinib getting approvals for these tumors. Nowadays, immune checkpoint inhibitors form a new landscape in cancer therapeutics and have already shown remarkable responses in various tumors. Studies in melanoma, non-small-cell lung cancer, and renal cell carcinoma are very encouraging as these inhibitors have increased survival rates. The purpose of this review is to present alternative approaches for the treatment of the GIST patients, such as combinations of immunotherapy and novel inhibitors with traditional therapies (tyrosine kinase inhibitors).

Clinical features and immunohistochemistry profile of biopsy-proven gastric gastrointestinal stromal tumor (GIST): a description of 5 years case series and literature review of GIST

Background

Gastrointestinal stromal tumor (GIST) was the most common mesenchymal tumor of the gastrointestinal tract predominately occurring in the stomach. Although GIST was a rare disease, it was considered to be a life-threatening malignancy.

Objective

To explore the current status of gastric GIST in Thai patients.

Method

The medical records of patients who were diagnosed with histologically proven gastric GIST from 2012 to 2016 in King Chulalongkorn Memorial Hospital were reviewed.

Results

Of 22 patients, there were 14 (63.6%) females and 8 (36.4%) males with the mean age of 62.6 ± 14.8 years. The average duration before the first presentation was 12 weeks. The initial symptoms were upper gastrointestinal bleeding (50.0%) followed by abdominal pain (31.8%). Tumor mostly located at the proximal part (fundus and cardia) in 20 (90.9%) patients. At the time of the diagnosis, three patients (13.6%) had distant metastasis. Of this group, 77.3% underwent surgical treatment.

Discussion

Although gastric GIST was an uncommon disease, early diagnosis and prompt treatment could save the lives of many patients.

Decreasing the burden: An unusual GIST presentation, a case report

•

GIST may be refractory to treatment with only Imatinib and Sunitinib.

•

Surgical debulking in addition to molecular therapy for patients with severely extensive GISTs.

•

Debulking promotes an improved response to chemotherapy, decreases symptoms of obstruction and improves pain, and increases the patient’s ability in activities of daily living.

•

Debulking this large mass significantly reduced tumor burden and thus promoted to an overall increase in chemotherapy effectivity.

Introduction

Gastrointestinal stromal tumours (GIST) are notoriously one of the most common mesenchymal tumours of the alimentary canal. Most commonly originating from the gastric stroma, they are recognized by their mass effects on the abdominal cavity. Recurrence frequently occurs with GIST and these tumours may become refractory to tyrosine kinase inhibitors (TKIs). Therefore, resection may be indicated for improved outcomes.

Presentation of case

We present a 52-year-old African American male with a surgical history of GIST resection with recurrence that came to the emergency room with worsening diffuse abdominal pain. The tumour was refractory to two TKIs, Imatinib and Sunitinib. Computed tomography (CT) of the abdomen and pelvis was done which showed severe metastatic disease with carcinomatosis, multiple dilated loops of small bowel in the left hemiabdomen without discrete transition point. After seventeen days on nasogastric tube, antiemetics, the patient worsened, and it was decided to go to surgery. In this report, attention is focused on the surgical approach of tumour debulking with subsequent Regorafenib therapy for decreased obstructive symptoms and improved quality of life.

Conclusion

This case serves as an example of the importance of surgical debulking in addition to molecular therapy for patients with severely extensive GISTs. Tumour debulking is important to decrease tumour burden, improve chemotherapeutic response and improve quality of life especially in persons refractory to pharmacological therapy.

Gastrointestinal Stromal Tumors: A Single Institution Experience of 176 Surgical Patients

Large single-institution series of patients undergoing resection for gastrointestinal stromal tumors (GIST) are lacking. Clinicopathologic characteristics and postoperative outcomes were retrospectively collected and analyzed from patients undergoing resection for GIST from 2002 to 2011. One hundred seventy-six patients were identified; 156 underwent resection of primary nonmetastatic disease. KIT mutations were identified in 131 patients (84.0%). Of the 156 patients with primary disease, the most common site was the stomach (75.6%). Tumors were categorized as very low (24.4%), low (35.9%), intermediate (12.2%), high (24.4%), or unknown (3.2%) risk. Symptomatic patients more often had high risk (35.6 vs 9.8%; P < 0.0001) and larger tumors (7.3 vs 3.0 cm; P < 0.0001). Forty-seven patients (30.1%) underwent laparoscopic resection (LR). Compared with open surgery, LR was performed for smaller tumors (3.8 vs 6.2 cm; P = 0.002). Positive margin rates were similar (4.3% LR vs 10.2% open; P = 0.346). Median follow-up for the 156 patients with primary tumors was 32.9 months; mean overall survival was 120.9 months (median not reached). Of the 20 patients with metastatic GIST (excluded from above analysis), five patients (25.0%) died of disease with a median follow-up of 15.9 months. Most patients with resectable primary GIST have a favorable prognosis. The presence of symptoms directly related to GIST may be associated with a poor prognosis and is likely related to increased tumor size. Laparoscopic resection is well tolerated and does not appear to compromise outcomes in well-selected patients. Highly selected patients with metastatic disease may benefit from resection.

Comparison between laparoscopic and endoscopic resections for gastric submucosal tumors

BACKGROUND/AIMS

Open resection/laparoscopic resection (LR) is the traditional treatment of gastric submucosal tumor (G-SMT). The endoscopic resection (ER) technology provides good results for G-SMT treatment but lacks sufficient evidence-based evidence. This retrospective study aimed to compare the clinical efficacy of ER [endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), and endoscopic full-thickness resection (EFR)] and LR [laparoscopic wedge resection (LWR) and laparoscopic subtotal gastrectomy (LSG)] for G-SMT.

PATIENTS AND METHODS

From January 2013 to January 2017, data of patients with G-SMT with tumor diameter <5 cm were collected from the database of The Affiliated Hospital of Qingdao University and classified based on surgical methods. Demographics, tumor characteristics, surgical outcomes, complications and tumor recurrence were recorded and compared.

RESULTS

Overall, 275 patients with G-SMT were enrolled: 152 underwent ER (ESD, n = 65; ESE, n = 23; EFR, n = 61) and 123 underwent LR (LWR, n = 93; LSG, n = 30). Age, sex, R0 resection rate, tumor location, type, recurrence and complications were not statistically significant (P > 0.05). The ER group had a significantly higher percentage of intraluminal tumor (94.1% vs 62.4%) and smaller tumor size (1.8 ± 0.8 vs 3.4 ± 1.2 cm) than the LR group. The ER group had less muscular tumors than the LR group (54.6% vs 70.7%). The ER group had no serosal tumor. The ER group had shorter hospitalization time, postoperative hospital stay and diet recovery time. The LR group had shorter operation time, less cost and less blood loss.

CONCLUSION

ER and LR are safe and effective treatments for SMT. For small intraluminally growing SMT, ER is better than LR.

FULL-THICKNESS ENDOSCOPIC GASTRIC RESECTION USING A STAPLER AND GASTROSTOMY: A FEASIBILITY STUDY

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) is currently the most frequently performed bariatric procedure in Turkey. The goal of weight reduction surgery is not only to decrease excess weight, but also to improve obesity related comorbidities and quality of life (QoL).

AIM

To evaluate the impact of LSG on patient quality of life, weight loss, and comorbidities associated with morbid obesity according to the updated BAROS criteria.

METHODS

Eleven hundred thirty-eight adult patients were undergone to LSG by our bariatric surgery team between January 2013 and January 2016. A questionnaire (The Bariatric Analysis and Reporting Outcome System - BAROS) was published on social media. The data on postoperative complications were collected from hospital database.

RESULTS

Number of respondants was 562 (49.4%). Six of 1138 patients(0.5%) had leakage. All patients who had leakage were respondants. The overall complication rate was 7.7%. After a mean period of 7.4±5.3 months(1-30), mean excess weight loss was 71.3±27.1% (10.2-155.4). The respondants reported 772 comorbidities. Of these, 162 (30%) were improved, and 420 (54.4%) were resolved. The mean scores for QoL were significantly increased after LSG (range, p<0.05 to <0.001). Of the 562 patients, 26 (4.6%) were classified as failures; 86 (15.3%) fair; 196 (34.9%) good; 144 (25.6%) very good, and 110 (19.6%) excellent results according to the updated BAROS scoring system.

CONCLUSION

LSG is a highly effective bariatric procedure in the manner of weight control, improvement in comorbidities and increasing of QoL in short- and mid-term.

Tumor rupture of gastric gastrointestinal stromal tumors during endoscopic resection: a risk factor for peritoneal metastasis?

BACKGROUND AND STUDY AIMS

 Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal tract. Up to the present time, complete surgical excision has been the standard treatment for primary GISTs greater than 2 cm. It is well known that tumor rupture during surgery is an independent risk factor for peritoneal metastasis; however, it is not known whether the risk of peritoneal metastasis increases in cases where the tumor is ruptured during endoscopic resection.

PATIENTS AND METHODS

 A total of 195 patients treated for GIST between January 2014 and December 2016 in our hospital were enrolled in this study. They were divided into two groups according to whether the tumor was ruptured during endoscopic resection. The rate of peritoneal metastasis in patients in the two groups who also suffered perforation was investigated from the follow-up results.

RESULTS

 Approximately 55.4 % of all patients were female and the average age of the study group was 59.0 ± 10.3 years. Of the 195 patients, the tumors in 27 were ruptured and the remaining 168 patients underwent en bloc resection. There was no statistically significant difference in gender or age between the two groups. The median tumor size (maximum diameter) in all patients was 1.5 cm (0.3 - 5.0 cm): 2.5 cm (0.8 - 5.0 cm) and 1.4 cm (0.3 - 4.0 cm) in the tumor rupture group and en bloc resection group, respectively ( P  < 0.001). Most of the tumors were located in the gastric fundus. At a median follow-up of 18.7 ± 10.2 months, neither tumor recurrence (liver metastasis, peritoneal metastasis, local recurrence) nor mortality related to GISTs were detected.

CONCLUSIONS

 Tumor rupture during endoscopic resection of gastric GISTs may not be a risk factor for peritoneal metastasis.

MiR-320a inhibits gastric carcinoma by targeting activity in the FoxM1-P27KIP1 axis

MicroRNAs (miRNAs) regulate tumorigenesis by inhibiting gene expression. In this study, we showed that miR-320a expression is decreased in human gastric cancer tissues and correlates inversely with expression of FoxM1, a key cell cycle regulator involved in gastric carcinoma. By contrast, the expression of P27^KIP1, a downstream effector of FoxM1, correlates positively with miR-320a levels. Luciferase assays indicate that miR-320a suppresses FoxM1 expression, and in vitro recovery tests using FoxM1 siRNA indicate miR-320a inhibits gastric cancer cell proliferation by suppressing activity in the FoxM1-P27^KIP1 axis. In vivo, nude mice injected with BGC-823 gastric cancer cells expressing a miR-320a inhibitor exhibit faster tumor growth than mice injected with control cells. Analysis of FoxM1 and P27^KIP1 expression in tumor tissues indicates that miR-320a suppression increases the tumor growth by enhancing FoxM1-P27^KIP1 signaling. These results thus reveal the crucial role played by miR-320a in limiting gastric carcinoma by directly targeting FoxM1- P27^KIP1 axis.

Gastrointestinal stromal tumor (GIST) with liver metastases: An 18-year experience from the GIST cooperation group in North China

Approximately 40% to 50% of gastrointestinal stromal tumor (GIST) patients will have recurrence or metastases after resection of the primary lesion, and the most common affected sites will be liver and peritoneum. Imatinib has been considered as the first-line therapy of metastatic GIST. Surgery for metastases is proposed when possible. Furthermore, there are controversies concerning hepatic resection and systemic tyrosin kinase inhibitors (TKIs). The therapeutic conditions and long-term outcome of GIST patients with liver metastases in northern China remain unknown.The clinical, pathological, and follow-up data of 144 GIST patients, who had liver metastases between June 1996 and June 2014 from 3 tertiary cancer centers in northern China, were reviewed.Thirty-two cases (22.2%) had hepatectomy with 23 (23/32, 71.9%) R0 resections and 9 (9/32, 28.1%) R1/R2 resections, respectively. Twenty-three patients were given imatinib postoperatively. Furthermore, 98 (68.1%) patients were given TKIs only to control disease progression, and sunitinib was considered after imatinib failure in 12 patients. The 1-, 3- and 5-year survival rate was 82%, 51%, and 24%, with a median overall survival of 48 months for all patients. Patients who had hepatic resection combined with TKIs had a tendency of improved outcome, and the median survival time was 89 months. This was in contrast to patients who received TKIs only, in which median survival time was 53 months. Patients who received imatinib plus sunitinib had a tendency of longer survival time, compared with patients who received imatinib only (not reached vs 50 months).TKIs combined with hepatic resection had a role in improving the outcome of GIST patients with liver metastases.

A Case of a Gastrointestinal Stromal Tumor Diagnosed at the Postpartum Period

Introduction. We discuss a rare gastrointestinal stromal tumor (GIST) case detected at the 10th postpartum week and we want to pay attention to the challenges and improvements in the diagnosis, surgery, chemotherapy, and follow-up of this rare tumor accompanied with the review of the current literature. Case Presentation. A 32-year-old multiparous woman presented with abdominal swelling 10 weeks after her second vaginal birth. Abdominal examination revealed a mass starting from the pelvic level and extending to the right upper quadrant. Radiological examinations showed a solid, multiloculated, and hypervascular mass starting from the pelvis and extending to the transverse colon. En bloc mass with a 20 cm jejunal segment resection and a left pelvic side wall peritonectomy with omentectomy was performed. The pathologic examination revealed a high-risk GIST which originated from the jejunum and disseminated to the peritoneum. The patient has been given imatinib 400 mg/day since then. She did not reveal any progression during the 15-month follow-up postoperatively. Conclusion. GIST tumors are rare and there is not sufficient information in the literature regarding its management. In this patient having high risk GIST and GIST sarcomatosis we successfully treated the patient by surgery and adjuvant imatinib chemotherapy.

Metastatic Liver Disease Associated with Gastrointestinal Stromal Tumors: Controversies in Diagnostic and Therapeutic Approach

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal lesions of the GI tract. They are considered to originate from neoplastic transformation of either the intestinal pacemaker cells of Cajal or the precursor pluripotential stem cells. The genetic basis of GIST growth is an activating mutation of two receptor tyrosine kinases. Recent epidemiologic studies demonstrate that the GIST prevalence is approximately 20/1000000/year. Although GISTs develop in every part of the GI tract, stomach remains the most common localization. About 80 % of the patients experience tumor recurrence or hepatic metastasis after radical resection. GIST liver metastases are usually multiple, large in diameter, and localized in both lobes. In addition, GISTs are usually completely asymptomatic, discovered incidentally. Symptoms are not typical and depend on the location, size, and aggressiveness of the tumor.

DISCUSSION

Diagnostic evaluation is based on imaging techniques, such as computed tomography, magnetic resonance imaging, positron emission tomography, and endoscopic ultrasound. Despite recent research on the therapeutic strategies against GISTs, surgical resection appears the only potentially curative approach. For the advanced metastatic disease, imatinib, a tyrosine kinase inhibitor, has been proposed neoadjuvantly with the surgery performed after the adequate reduction of tumor burden. The aim of this review was to evaluate the results of surgical treatment for metastatic GIST with special reference to the extent of its histological spread and to present the recent literature in order to provide an update on the current concepts of advanced surgical management of this entity.

A lethal mesenteric gastrointestinal stromal tumor: a case report and review of the literature

Gastrointestinal stromal tumors (GISTs) arising from the mesentery are very rare. Here, we report a 53-year old man with a huge lobulated cystic-solid tumor in the left lower quadrant of the abdomen, which had been proved clinically and radiographically. Surgical resection showed that the large mass was noted at the mesentery of small intestine. Grossly, the largest diameter of the mass were measured up to 23 cm, and poorly circumscribed. Histological observation demonstrated it as a malignant GIST with positive CD117 (c-kit) staining. Mitotic figures were frequently observed up to 110 per 50 high power fields. Soon after the surgery, the patient experienced local recurrence with quick growth. The patient received targeted therapy (imatinib mesylate) but had no ideal effect. The patient died nine months after the operation because of rapid disease progression.

Gastrointestinal stromal tumors: treatment patterns of a population-based sample

OBJECTIVES

The National Cancer Institute (NCI) annually confirms therapy with treating physicians on a sample of patients diagnosed with a specific cancer.

METHODS

Using the NCI Patterns of Care data, treatment patterns were examined on a population-based sample of patients diagnosed with gastrointestinal stromal tumors (GIST) in 2008.

RESULTS

A random sample of 323 of 405 GIST patients registered in SEER was selected. Most patients had gastric GISTs, were ≥ 65 years, white, had private insurance, and treated in a hospital with a residency program. Surgery was primarily performed in patients with non-metastatic disease (94%), in which: 26, 12, and 36% were at low, intermediate, and high-risk of recurrence, respectively. Amongst low-risk patients, ∼ 30% received adjuvant therapy. Amongst patients at higher risk, 26-40% did not receive adjuvant therapy. Imatinib was the most common targeted therapy administered. On multivariate analysis, age and risk-group were associated with receipt of adjuvant targeted therapy.

CONCLUSIONS

Our study shows that in 2008, the majority of patients diagnosed with GIST received appropriate surgical and adjuvant therapies. However, a considerable subset may have been overtreated and undertreated. Future studies identifying factors that impact the delivery of adjuvant therapy should be conducted.

Endoscopic full-thickness resection and laparoscopic surgery for treatment of gastric stromal tumors

AIM: To assess the effectiveness of endoscopic full-thickness resection (EFR) and laparoscopic surgery in the treatment of gastric stromal tumors arising from the muscularis propria.

METHODS: Out of 62 gastric stromal tumors arising from the muscularis propria, each > 1.5 cm in diameter, 32 were removed by EFR, and 30 were removed by laparoscopic surgery. The tumor expression of CD34, CD117, Dog-1, S-100, and SMA was assessed immunohistochemically. The operative time, complete resection rate, length of hospital stay, incidence of complications, and recurrence rate were compared between the two groups. Continuous data were compared using independent samples t-tests, and categorical data were compared using χ² tests.

RESULTS: The 32 gastric stromal tumors treated by EFR and the 30 treated by laparoscopic surgery showed similar operative time [20-155 min (mean, 78.5 ± 30.1 min) vs 50-120 min (mean, 80.9 ± 46.7 min), P > 0.05], complete resection rate (100% vs 93.3%, P > 0.05), and length of hospital stay [4-10 d (mean, 5.9 ± 1.4 d) vs 4-19 d (mean, 8.9 ± 3.2 d), P >0.05]. None of the patients treated by EFR experienced complications, whereas two patients treated by laparoscopy required a conversion to laparotomy, and one patient had postoperative gastroparesis. No recurrences were observed in either group. Immunohistochemical staining showed that of the 62 gastric stromal tumors diagnosed by gastroscopy and endoscopic ultrasound, six were leiomyomas (SMA-positive), one was a schwannoglioma (S-100 positive), and the remaining 55 were stromal tumors.

CONCLUSION: Some gastric stromal tumors arising from the muscularis propria can be completely removed by EFR. EFR could likely replace surgical or laparoscopic procedures for the removal of gastric stromal tumors.

Large cystic-based gastrointestinal stromal tumor: A case report

A 60-year-old male with increasing abdominal distension was admitted to The Fifth Affiliated Hospital of Guangzhou Medical University (Guangzhou, China). The abdominal sonogram exhibited a huge abdominal cystic-based mass with solid components in the left upper quadrant. A contrast-enhanced computed tomography scan of the abdomen revealed a large heterogeneous cystic solid tumor, but the source of the tumor could not be determined. The laparotomy demonstrated a huge cystic-based tumor with an integrated cystic wall, arising from the posterior wall of the gastric body. Multiple septa and ~3,500 ml of yellowish fluid were found in the cystic cavity. Pathological analysis showed that the tumor contained a mixture of polygonal and spindle cells. Immunohistochemical study indicated that the tumor cells were positive for CD117 and CD34. The final diagnosis was gastric gastrointestinal stromal tumor. The patient recovered well and no recurrence or metastasis was identified following a 12-month follow-up.

The GIST of targeted therapy for malignant melanoma

The high response rates to the tyrosine kinase inhibitor imatinib in KIT-mutated gastrointestinal stromal tumors (GIST) has led to a paradigm shift in cancer treatment. In a parallel fashion, the field of melanoma is shifting with the utilization of targeted therapy to treat BRAF-mutated melanoma. We reviewed published literature in PubMed on GIST and melanoma, with a focus on both past and current clinical trials. The data presented centers on imatinib, vemurafenib, and most recently dabrafenib, targeting KIT and BRAF mutations and their outcomes in GIST and melanoma. The BRAF(V600E) melanoma mutation, like the KIT exon 11 mutation in GIST, has the highest response to therapy. High response rates with inhibition of KIT in GIST have not been recapitulated in KIT-mutated melanoma. Median time to resistance to targeted agents occurs in ~7 months with BRAF inhibitors and 2 years for imatinib in GIST. In GIST, the development of secondary mutations leads to resistance; however, there have been no similar gatekeeper mutations found in melanoma. Although surgery remains an important component of the treatment of early GIST and melanoma, surgeons will need to continue to define the thresholds and timing for operation in the setting of metastatic disease with improved targeted therapies. Combination treatment strategies may result in more successful clinical outcomes in the management of melanoma in the future.

Clinicopathologic factors predicting outcomes in patients with gastrointestinal stromal tumors of the rectum and colon

Limited information is available concerning the clinicopathologic profile of colorectal gastrointestinal stromal tumors (GISTs), which are relatively rare, as well as survival rates following surgical resection. The present study was designed to describe the clinicopathologic characteristics of patients with colorectal GISTs and identify potential factors that may predict postoperative survival outcomes. We reviewed the medical records of 67 patients with colorectal GISTs who underwent surgical resection between January 2000 and December 2012. Clinicopathologic factors affecting overall survival were assessed using the Kaplan-Meier method and multivariate Cox proportional hazards models. The median age at diagnosis was 57 years (range, 32-79 years), with a male-to-female ratio of 1.68. Tumor size varied from 0.2 to 11 cm, with a median size of 5.7 cm. Sixty-two tumors (93%) were positive for CD117, 53 (79%) for CD34, 6 (9%) for PDGFRA, 15 (22%) for SMA, 5 (8%) for S100, and 39 (58%) for vimentin. The overall median survival time was 54 months (95% confidence interval, 32-59 months), and the 1-, 3-, and 5-year overall survival rates were 89.6, 63.9, and 34.4%, respectively. High-risk tumors (determined by histologic grade, size, and other histologic variables) were associated with poor prognosis (hazard ratio, 1.83; 95% confidence interval, 1.21-2.78), and patients who received adjuvant treatment with imatinib had significantly longer median overall survival times than patients who did not (hazard ratio, 0.43; 95% confidence interval, 0.24-0.80). In patients with colorectal GISTs, high-risk tumor histologic grade can predict poor prognosis, and patients may benefit from adjuvant treatment with imatinib. Findings from the present study may provide information to establish evidence-based management strategies for colorectal GISTs.

Endoscopic therapy for gastric stromal tumors originating from the muscularis propria

AIM: To explore endoscopic therapy methods for gastric stromal tumors originating from the muscularis propria.

METHODS: For 69 cases diagnosed as gastric stromal tumors originating from the muscularis propria, three types of endoscopic therapy were selected, based on the size of the tumor. These methods included endoscopic ligation and resection (ELR), endoscopic submucosal excavation (ESE) and endoscopic full-thickness resection (EFR). The wound surface and the perforation of the gastric wall were closed with metal clips. Immunohistostaining for CD34, CD117, Dog-1, S-100 and smooth muscle actin (SMA) was performed on the resected tumors.

RESULTS: A total of 38 cases in which the tumor size was less than 1.2 cm were treated with ELR; three cases were complicated by perforation, and the perforations were closed with metal clips. Additionally, 18 cases in which the tumor size was more than 1.5 cm were treated with ESE, and no perforation occurred. Finally, 13 cases in which the tumor size was more than 2.0 cm were treated with EFR; all of the cases were complicated by artificial perforation, and all of the perforations were closed with metal clips. All of the 69 cases recovered with medical treatment, and none required surgical operation. Immunohistostaining demonstrated that among all of the 69 gastric stromal tumors diagnosed by gastroscopy, 12 cases were gastric leiomyomas (SMA-positive), and the other 57 cases were gastric stromal tumors.

CONCLUSION: Gastric stromal tumors originating from the muscularis propria can be treated successfully with endoscopic techniques, which could replace certain surgical operations and should be considered for further application.