[Current research status and progress of primary esophageal gastrointestinal stromal tumors in China]

Primary esophageal gastrointestinal stromal tumors (GIST) is a rare independent disease with clinicopathological and molecular features different from other mesenchymal tumors. Authors searched and reviewed associated reports and summarized the morbidity trends, characteristics, diagnosis and treatment of esophageal GIST in China. Data show that the incidence and detection rate of esophageal GIST presents the rising trend. Imaging has some characteristics. Ultrasonography and CT are main methods and effective examinations to detect and prompt diagnosis of esophageal GIST. Pathology and immunohistochemistry are the evidence for a definite diagnosis. Risk classification is the important basis for selecting surgical methods and predicting prognosis. Surgery is the mainstay treatment. Very low and low risk patients with tumors less than 3 cm can choose endoscopic resection. For tumors of 3 to 5 cm, tumor resection must be considered. Thoracoscopy appears to be the first choice for surgery. Medium and high risk patients with tumors >5 cm should be treated with partial resection of esophagus. Surgery combined with targeted therapy and neoadjuvant therapy is the main treatment pattern and research direction.

[Targeted therapy combined with immunotherapy in gastrointestinal stromal tumor: a new era of hope and challenges]

New immunotherapy represented by immune checkpoint inhibitor therapy and chimeric antigen receptor T-Cell immunotherapy (CAR-T) has already become hot trend in the treatment of malignant tumors. In gastrointestinal stromal tumor (GIST), with notable tumor-infiltrating immune cells existing in GIST tissues and immunological effects reported in imatinib mesylate (IM) treatment, the clinicians and researchers started to realize the possibilities of immunotherapy in GIST. Recent studies reported that PD-1/PD-L1 or CTLA-4 blockade may enhance the T-cell activity and anti-tumor effect of targeted therapy, which can be applied in advanced GIST, and anti-KIT CAR T-cells indicated a new immunotherapeutic targeted strategy for GIST patients with TKI resistance. All the immunotherapies in GIST mentioned above are frontline researches but their efficacies still need more evidence from clinical trials to verify.

Clinicopathologic study of succinate-dehydrogenase-deficient gastrointestinal stromal tumors: A single-institutional experience in China

Gastrointestinal stromal tumors (GISTs) that are not driven by kinase mutations, as are most GISTs, often show loss of function of the succinate dehydrogenase (SDH) complex and are considered SDH-deficient GISTs. SDH-deficient GISTs share many distinct characteristics compared with conventional GISTs. However, data regarding these characteristics, particularly among Asian people, are relatively limited. The objective of this study was to characterize the clinicopathologic characteristics, treatment, and prognosis of these uncommon GISTs.This retrospective observational study enrolled 12 patients with SDH-deficient GISTs, who were selected from 335 patients with GIST diagnosed at our institution between October 31, 2013 and October 31, 2016 by succinate dehydrogenase subunit B staining.There were 8 male and 4 female patients, with a median age of 57 years (range, 21-73 years). Ten patients (83.3%) were diagnosed at or after the age of 40 years and represented 7.2% (10/138) of the entire population of elderly patients with gastric GISTs. The tumor size ranged from 3 to 19 cm (median, 7 cm); the primary tumor was multifocal in 6 cases (50%), and tumors had a multinodular or plexiform architecture in 10 cases (83.3%). Ten cases (83.3%) showed pure epithelioid morphology, with the remaining 2 cases (16.7%) showing mixed histologic subtype. Lymph node metastasis was found at the time of primary resection in 50% (3/6) of patients. Four cases (33.3%) had distant metastasis at presentation. Four patients (33.3%) developed disease progression during imatinib treatment after initial resection, but all of these patients regained disease control when the treatment was altered to sunitinib targeted therapy.SDH-deficient GISTs arise exclusively in the stomach and account for approximately 7.4% (12/162) of gastric GISTs. Moreover, those affecting people older than 40 years are not uncommon and sunitinib may work well for cases showing treatment failure with imatinib.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Current research and treatment for gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and have gained considerable research and treatment interest, especially in the last two decades. GISTs are driven by mutations commonly found in the KIT gene and less commonly in the platelet-derived growth factor receptor alpha gene, BRAF gene and succinate dehydrogenase gene. GISTs behave in a spectrum of malignant potential, and both the tumor size and mitotic index are the most commonly used prognostic criteria. Whilst surgical resection can offer the best cure, targeted therapy in the form of tyrosine kinase inhibitors (TKIs) has revolutionized the management options. As the first-line TKI, imatinib offers treatment for advanced and metastatic GISTs, adjuvant therapy in high-risk GISTs and as a neoadjuvant agent to downsize large tumors prior to resection. The emergence of drug resistance has altered some treatment options, including prolonging the first-line TKI from 1 to 3 years, increasing the dose of TKI or switching to second-line TKI. Other newer TKIs, such as sunitinib and regorafenib, may offer some treatment options for imatinib-resistant GISTs. New molecular targeted therapies are being evaluated, such as inhibitors of BRAF, heat shock protein 90, glutamine and mitogen-activated protein kinase signaling, as well as inhibitors of apoptosis proteins antagonist and even immunotherapy. This editorial review summarizes the recent research trials and potential treatment targets that may influence our future patient-specific management of GISTs. The current guidelines in GIST management from Europe, North America and Asia are highlighted.

Supraclavicular lymph node metastases from malignant gastrointestinal stromal tumor of the jejunum: A case report with review of the literature

Gastrointestinal stromal tumors (GISTs) represent the most common mesenchymal tumors of the alimentary tract. These tumors may have different clinical and biological behaviors. Malignant forms usually spread via a hematogenous route, and lymph node metastases rarely occur. Herein, we report a patient with a jejunal GIST who developed supraclavicular lymph node metastasis. We conclude that lymphatic diffusion via the mediastinal lymphatic station to the supraclavicular lymph nodes can be a potential metastatic route for GISTs.

[Progression of diagnosis and treatment in primary malignant small bowel tumor]

Primary malignant small bowel tumor as a rare kind of intestinal tumor is associated with a poor prognosis. The pathological types were various and complicated, such as adenocarcinoma, neuroendocrine tumor, malignant lymphoma, and malignant stromal tumor. The atypical early stage symptom resulted in difficult diagnosis at early stage, high misdiagnosis rate and lack of standard therapy schemes and means. In the past, X-ray, CT, MRI, and PET-CT were the main examination methods for primary small bowel tumor. However, with the development of radiology, a series of new diagnosis methods, including electronic enteroscopy, capsule endoscopy, multi-slice spiral CT enteroclysis and so on, promotes the diagnosis accurate rate. Surgery is still the most important method in the small bowel tumor treatment, and the alternative of the surgical method should depend on the tumor location, size and relationship with the adjacent organs. Application of the laparoscopic surgery for the small bowel tumor is still in the initial stage. Besides, some researches have confirmed that chemotherapy, radiotherapy, target therapy and endocrinotherapy have effects on the specific kind of small bowel tumor. Therefore this article will review the epidemiology, pathology, diagnosis and treatment of the primary malignant small bowel tumors.

Ovarian gastrointestinal stromal tumor: does this diagnosis exist?

Gastrointestinal stromal tumors (GISTs) are rare gastrointestinal (GI ) tract tumors. Those tumors rarely arise extra intestinally; within omentum, mesentery, and rarely uterus. The authors report a case of myxoid variant of GIST arising in the ovary with no evidence of a primary tumor in the GI tract. Surgeons as well as gynecologists should bear this possibility in mind when managing pelvic masses.

[Changes of diagnosis and treatment for gastrointestinal stromal tumors during a 18-year period in four medical centers of China]

OBJECTIVE

To elucidate the historic and current diagnosis and treatment status of gastrointestinal stromal tumor (GIST) in the Chinese population based on four high volume databases.

METHODS

Clinicopathological data of GIST patients with follow-up information between January 1998 and December 2015 from Sun Yat-sen University Cancer Center, Union Hospital of Huazhong University of Science and Technology, Southern Medical University Nanfang Hospital and Guangdong General Hospital were retrospectively analyzed. Kaplan-Meire method was used to draw survival curve. The accumulative survival rate was calculated by life table method. Comparison of survival rate among groups was examined by Log-rank test.

RESULTS

A total of 2 610 cases were enrolled into the study, including 667(25.6%) cases from Sun Yat-sen University Cancer Center, 754(28.9%) cases from Union Hospital of Huazhong University of Science and Technology, 692(26.5%) cases from Southern Medical University Nanfang Hospital and 497 (19.0%) cases from Guangdong General Hospital. There were 1 394 male and 1 216 female cases with the ratio of 1.15 to 1.00. The age of patients was from 18 to 95 (median 58.0) years old. Three-year was used as a time stage, then 18 years were divided into 6 stages. New GIST patients increased gradually year by year. There were 13(0.5%) cases during 1998 to 2000, 68(2.6%) cases during 2001 to 2003, 256(9.8%) cases during 2004 to 2006, 517 (19.8%) cases during 2007 to 2009, 814(31.2%) cases during 2010 to 2012, and 942 (36.1%) cases during 2013 to 2015. Primary GIST sites were esophagus in 50(1.9%) cases, stomach in 1 686(64.6%) cases, duodenum in 206 (7.9%) cases, jejunum and ileum in 446 (17.1%) cases, colon and rectum in 133 (5.1%) cases, and non-gastrointestinal tract in 89 (3.4%) cases. GIST lesions of 2 404(92.1%) cases located in the primary sites and relapse/metastasis occurred in 206 cases when consulting. Among 206 relapse/metastasis cases, liver metastasis was found in 126 (61.2%) cases, abdominal cavity/pelvic cavity metastasis in 64 (31.1%) cases, liver plus abdominal cavity/pelvic cavity metastasis in 12 (5.8%) cases, and other site metastasis in 4 (1.9%) cases. Among all the patients, 352 received gene detection, including 1 (0.4%) during 2004 to 2006, 7 (1.4%) during 2007 to 2009, 150 (18.4%) during 2010 to 2012, and 194 (20.6%) during 2013 to 2015. Most of the primary oncogenic mutational site occurred in c-Kit, including 30 (8.5%) cases in exon 9, 242 (68.8%) cases in exon 11, 4 (1.1%) cases in exon 13, 2 (0.6%) cases in exon 17, while 3 (0.9%) cases in PDGFRA exon 12 and 20 (5.7%) cases in PDGFRA 18, besides, no mutations of KIT and PDGFRA were detected in 51 (14.5%) cases. A total of 2 202 cases underwent operation, including 2 038 (92.6%) of radical resection and 164 (7.4%) of palliative resection. Among 2 038 patients undergoing radical resection, 450 (22.1%) cases were very low risk, 593 (29.1%) cases were low risk, 283 (13.9%) cases were moderate risk and 712 (34.9%) cases were high risk according to NIH risk classification. Of 995 patients with moderate and high risk, 550(55.3%) cases received postoperative imatinib adjuvant therapy, whose ratio in above 6 time stages was as follows: 0, 42.8%(12/28), 19.8%(20/101), 9.8% (21/215), 65.7% (176/268) and 85.6% (321/375). Of 206 relapse/metastasis patients, 200 (97.1%) cases received imatinib as the first-line therapy, and 22 (10.7%) received sunitinib as the second-line therapy. A total of 1 743 patients had complete follow-up data and median follow-up time was 35.9 (0.1 to 173.8) months. The 5-year overall survival rates in very low, low, moderate and high risk patients were 100%, 97%, 95% and 78% respectively.

CONCLUSION

This retrospective study provides the largest data of GIST and indicates the historic changes of clinicopathological characteristics, diagnosis and treatment of GIST for further domestic GIST research.

Clinical outcomes of patients with gastrointestinal stromal tumor in phase I clinical trials

BACKGROUND

The prognosis of patients with gastrointestinal stromal tumor (GIST) after the failure of standard therapies is poor with supportive care alone. Guidelines recommend clinical trials, and patients with good performance status following standard therapies are often eligible for phase I clinical trials of investigational agents; however, there are no detailed reports on the clinical outcomes of GIST patients enrolled in these trials.

METHODS

We retrospectively reviewed the clinical outcomes of 21 consecutive GIST patients who were enrolled in one or more phase I clinical trials at a single center between March 2009 and November 2014.

RESULTS

The median age was 57 years, and the median number of previous lines of standard chemotherapy was three. Chemotherapy before enrollment in a phase I clinical trial included imatinib, sunitinib, and regorafenib in 100, 95, and 43 % of patients, respectively. None of the patients achieved objective response. Ten patients (47.6 %) were determined to be stable according to the Response Evaluation Criteria in Solid Tumors; four of them (19.0 %) maintained their status for more than 24 weeks. Four patients achieved partial response according to the Choi criteria. No dose-limiting toxicity was observed; however, severe adverse events and grade 3 or higher toxicities were reported in one (4.8 %) and two patients (9.5 %), respectively. Although no treatment-related deaths occurred, one patient (4.8 %) died within 30 days after the last drug administration because of disease progression. The median progression-free survival was 1.9 months, and the median overall survival time has not been reached.

CONCLUSIONS

Data suggested that phase I clinical trials were feasible and may provide prognostic benefits to GIST patients after standard therapies, indicating that enrollment in these studies may provide a treatment option for these patients.

[Multidisciplinary Treatment for High-Risk GIST of the Stomach]

A 59-year-old man underwent total gastrectomy(with D2 dissection)and cholecystectomy for gastric cancer and a submucosal tumor of the stomach. The specimen was immunohistochemically positive for c-kit, the Ki-67 label index was 10%, and the mitotic count was 20/HPF. Finally, the patient was diagnosed with high-risk gastrointestinal stromal cancer with normal type gastric cancer. After discharge from hospital, we started administration of TS-1 as adjuvant therapy for the gastric cancer. As multiple recurrences of the GIST in the abdomen developed, the patient underwent 3 radical local resections. Mutational analysis revealed a PDGFRA mutation in exon 18, which causes resistance to both imatinib and sunitinib. As he was refractory to imatinib, the patient received regorafenib. After a while, it caused liver failure, which required 7 rounds of plasmapheresis. The patient died from multiple organ failure resulting from multiple recurrences 4 years after the first surgery.

[Long-Term Survival of a Patient with Recurrent Duodenal GIST Treated with Various Molecular Targeted Drugs and TAE - A Case Report]

The patient was 66-year-old woman with anemia. A 6 cm GIST was diagnosed in the fourth portion of the duodenum using abdominal CT. Duodenal-jejunal segmental resection was performed for the GIST. Four years after surgery, multiple liver metastatic recurrences ofGIST were diagnosed using abdominal CT. The metastatic tumor was treated with imatinib, but the treatment caused adverse events such as leukocytopenia(Grade 2)and anemia(Grade 3). The treatment continued for 41 months while reduced or discontinued during the administration period. Sunitinib was administered, but the treatment caused a reduced platelet count(Grade 3), anemia(Grade 2), and melena(Grade 3). The treatment continued for 12 months while reduced or discontinued during the administration period. Regorafenib was administered and continued for 9 months. Thereafter, trancecatheter arterial embolization(TAE)was performed 5 times. The patient is alive 8 years and 3 months after recurrence.

Prevalence, Impact, and Correlates of Severe Fatigue in Patients With Gastrointestinal Stromal Tumors

CONTEXT

The introduction of the tyrosine kinase inhibitor (TKI) imatinib in the treatment of gastrointestinal stromal tumor (GIST) in 2000 was the start of a new era of targeted treatment. Since then, the median survival of patients with GIST has substantially increased. Prolonged survival and chronic TKI use are associated with treatment-induced symptoms, such as fatigue, which can compromise quality of life (QoL).

OBJECTIVES

This study determined the prevalence of severe fatigue in GIST patients compared to matched healthy controls, the impact of fatigue on daily life, and associations between fatigue and current TKI use.

METHODS

One hundred nineteen patients treated with surgery and/or a TKI for GIST were asked to participate. Participants completed questionnaires including the Checklist Individual Strength-Fatigue Severity scale (CIS-fatigue), Short-Form 36-Item Health Survey, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30, Fatigue Catastrophizing Scale, Self-Efficacy Scale, and the Hospital Anxiety and Depression Scale.

RESULTS

Eighty-nine GIST patients (75%) completed questionnaires, 61 patients (69%) were on a TKI. Prevalence of severe fatigue measured with CIS-fatigue was significantly higher in GIST patients (30%) than in 234 matched healthy controls (15%). The prevalence of severe fatigue did not differ significantly between patients receiving treatment with curative (29%) or palliative intent (36%). Severely fatigued patients reported lower QoL and more impairment on all functional domains. TKI use, more psychological distress, and lower physical functioning were associated with fatigue.

CONCLUSION

Severe fatigue occurs in 30% of GIST patients and in 33% of GIST patients on a TKI. The fatigue is disabling and is not only associated with current TKI use but also with psychological distress and physical functioning. GIST patients should be informed about these associated factors of fatigue that deserve appropriate management.

Gastrointestinal stromal tumour masquerading as a cyst in the lesser sac

Gastrointestinal stromal tumours (GISTs) are solid tumours of the gastrointestinal tract, mostly found in the stomach and intestine. They rarely present as cystic lesions. A 74-year-old woman referred to the hepatopancreaticobiliary unit, with 3 months history of upper abdominal discomfort. Abdominal ultrasound scan showed a large cystic lesion in the epigastric region suggestive of a pancreatic pseudocyst. The CT-scan showed a 6.6×6×6.3 cm size cyst related to the pancreas and extending to the hepatogastric omentum. Endoscopic ultrasound (EUS) scan was suggestive of a pancreatic pseudocyst. Aspirated Cyst fluid via EUS showed benign cytology with normal amylase, lipase and tumour markers (CEA, CA-19.9 and CA-125). She was referred as a case of pancreatic pseudocyst. After surgical excision, the histopathology confirmed the presence GIST in the wall of the cystic lesion. The possibility of GIST should be kept in mind in the presence of unusual features of a cyst on abdominal imaging.

Imaging of Gastrointestinal Stromal Tumors: From Diagnosis to Evaluation of Therapeutic Response

Once considered an obscure tumor entity with poor prognosis, gastrointestinal stromal tumors (GISTs) are nowadays recognized as the most common mesenchymal tumors of the alimentary tract. GISTs differ from other mesenchymal neoplasms at pathology since 90% of them exhibit strong immunohistochemical staining for KIT, a tyrosinase kinase growth factor receptor. In the early 2000s, the ability of imatinib mesylate, a tyrosine kinase inhibitor, to inhibit KIT established a new paradigm for cancer treatment. A reduction in lesion size may not be observed or may appear many months after therapy; thus, tumor response criteria alternative to the Response Evaluation Criteria in Solid Tumors were developed. This review highlights the role of imaging in the detection, characterization, preoperative staging, postoperative assessment, therapy-response evaluation and treatment-related toxicities. All this information is crucial in optimizing patient management. Contrast-enhanced computed tomography is the most commonly used modality for staging the disease and assessing treatment response, whereas positron-emission tomography adds valuable functional information. Magnetic resonance imaging (MRI) may also be useful, especially in ano-rectal GISTs. Diffusion-weighted MRI may provide promising indicators of tumor response to targeted molecular therapy. Radiologists and oncologists should be aware of all these issues related to GISTs, since multidisciplinary teams gathering different expertise are usually needed to properly treat patients with GISTs.

Huge Perineal Tumour: A Rare Presentation of Gastrointestinal Stromal Tumour of Rectum

Gastrointestinal stromal tumour (GIST) is a relatively rare neoplasm of gastrointestinal tract of which Rectal GIST is uncommon. It produces symptoms of per rectal bleeding or change in bowel habit. Recurrences following curative resection are predominantly intraabdominal, hepatic metastasis occurring at a median 20-25 months following the primary surgery. A 42 years old male presented a huge mass in hypogastrium, the size of which was reduced ofter neoadjuvant therapy for period of 1.5 years. He underwent abdominoperineal resection. He developed recurrences in perineum three times and in thigh at short intervals after primary resection. He also developed liver metastasis. He died two and half years after primary diagnosis. Rectal GIST should be included in differential diagnosis of intraabdominal mass and preoperative diagnosis based on histopathological as well as the immunohistochemical feature of the CD(117) and CD(34). Although complete surgical resection with negative tumour margin is the principal curative procedure for primary and non metastatic tumours, further studies are still needed for the determination of the most effective treatment strategy for patients of rectal GIST.

Clinical and pathological characteristics and their effect on survival in elderly patients with gastrointestinal stromal tumors

PURPOSE

Gastrointestinal stromal tumors (GISTs) are common tumors of the gastrointestinal tract. Their most frequent location is the stomach. Although the clinical and pathological characteristics of the disease are well-known, the clinical and pathological characteristics and the response to treatment are not clear in elderly patients. The purpose of this study was to evaluate the characteristics of GISTs in elderly patients with an aim at improving the therapeutic methodology and survival.

METHODS

In this study, clinicopathological characteristics, evaluation of treatments administered and survival analyses were performed in patients aged 65 years or above, whose data were registered via a web-based patient records system following admission to three centers.

RESULTS

A total of 85 patients aged 65 years or above were included in the study. According to the risk classification, 24 (28.2%) were in the low risk group, 20 (23.5%) in the moderate risk group, and 41 (48.3%) in high risk group, while no patient was in the very low risk group. At baseline, 70% of the patients had localized disease and 30% metastatic disease. The tumor was located in the stomach in the majority of the patients (45.6%). The tumor size most commonly seen was 5-10 cm (N=31; 36.4%). Of the 85 patients 23 (27%) were treated with imatinib 400 mg/d. Eight patients (9.4%) with metastatic disease switched from imatinib to sunitinib. At a median follow-up of 76 months (range 1-323), median overall survival (OS) was 72 months, without significant difference between elderly and younger patients.

CONCLUSION

Clinicopathological characteristics and their prognostic impact on the disease course of elderly GIST patients should be elucidated in depth. Since age didn't show prognostic importance, other parameters should be used as prognostic/predictive factors in the tyrosine kinase inhibitors era in order to obtain improved therapeutic results.

Synchronous Occurrence of Diffuse Large B-cell Lymphoma of the Duodenum and Gastrointestinal Stromal Tumor of the Ileum in a Patient with Immune Thrombocytopenic Purpura

A 64 year-old woman with steroid-dependent immune thrombocytopenia developed anemia. Esophagogastroduodenoscopy revealed the presence of a tumor, which was diagnosed to be diffuse large B-cell lymphoma, in the second portion of the duodenum. ¹⁸F-fluorodeoxy glucose positron emission tomography showed an increased uptake mass in the pelvic cavity as well as in the duodenum. Though the duodenal tumor disappeared after 4 cycles of chemotherapy, the pelvic mass did not shrink in size. As a result, laparoscopic resection of the pelvic tumor was performed and the tumor was histologically diagnosed to be a gastrointestinal stromal tumor. Subsequently, the patient was treated with 2 more cycles of the chemotherapy. Eventually, thrombocytopenia completely resolved.

Gastric and Small Bowel Tumors

The incidence of gastric adenocarcinoma has decreased in the United States over the past 70 years although it continues to have a poor prognosis. While radical resection was initially the primary treatment for adenocarcinoma of the stomach, systemic chemotherapy and radiation have been shown to play a role in prolonging survival in most patient populations. This chapter explores the evidence that guides treatment for gastric cancer today. It also discusses the treatment for gastrointestinal stromal tumors (GIST), and small bowel tumors. In addition to systemic therapies, this chapter explores the surgical management of gastric and small bowel tumors including the extent of the gastric lymph node dissection.

Rare case of intraintestinal stromal tumors in the patient with familial adenomatous polyposis

AIM

To describe the case of metachronous gastrointestinal stromal tumors in a proband with familial adenomatous polyposis (FAP), carrier of APC gene mutation in codon 1309.

MATERIAL AND METHODS

The physical examination, genealogical analysis and molecular genetic analysis of peripheral blood in 15-years-old girl with FAP and her sister, were carried out. Macroscopic, standard histological and immunohistochemical study of surgical specimens - intraintestinal tumors of the small intestine in proband was performed.

RESULTS

Extraintestinal manifestations, including congenital abnormalities of facial skeleton, typical for Gardner's syndrome, were observed in the sisters with FAP as the addition symptoms of the disease. Frameshift mutation in codon 1309 in the APC gene was detected in these patients. A rare neoplasia - metachronous gastrointestinal stromal tumor was found in proband 15 months after total colectomy for FAP. This is the third case described in the accessible medical literature.

CONCLUSION

The possible role of APC gene mutation in the development of mesenchymal neoplasms is discussed. The study of stromal tumors is important for understanding of their pathogenesis that will enable to develop effective targeted therapy.

[Mesenteric stromal tumor: report of a rare case and review of literature]

Les tumeurs stromales du mésentère sont des sarcomes rares du tube digestif. Nous rapportons un cas rare de tumeur stromale dans sa localisation mésentérique. Il s'agit d'un patient admis aux urgences pour abdomen aigu. La tomodensitométrie a objectivé un kyste abcédé du mésentère. L'exploration chirurgicale a retrouvé une tumeur du mésentère. Une exérèse monobloc de la tumeur a été réalisée. L'histologie avec immunohistochimie de la pièce opératoire a mis en évidence une tumeur stromale à risque intermédiaire de malignité. Un traitement adjuvant à base d'imatinib a été ensuite instauré. L’évolution a été simple, sans récidive, avec un recul de 8 mois. Au plan pronostique, selon les critères de Fletcher et de l'AFIP (Armed Forces Institute of Pathology), la tumeur était classée à un risque élevé de récidive. Les tumeurs stromales du mésentère sont exceptionnelles surtout dans leur présentation clinique d'abdomen aigu. Le diagnostic repose sur l'immunohistochimie et le traitement des formes localisées sur la chirurgie, associée à l'imatinib en traitement adjuvant.

The GOLD ReGISTry: a Global, Prospective, Observational Registry Collecting Longitudinal Data on Patients with Advanced and Localised Gastrointestinal Stromal Tumours

BACKGROUND

Gastrointestinal stromal tumours (GISTs) are the most common gastrointestinal sarcomas. This global, prospective registry followed patients with advanced or localised GIST (2007-2011).

METHODS

Current and evolving diagnostics, treatments and outcome measures in patients with GIST were assessed. Eligible patients were diagnosed with advanced or localised GIST within 15months of registry entry. No treatment plan was prescribed, and no visit schedule was mandated. Treating physicians recorded patient information, including tumour response, diagnostic methods, medications, surgeries performed, mutation status and adverse events leading to dose/medication changes. Survival outcomes were estimated using the Kaplan-Meier method. Other data were analysed using descriptive statistics.

RESULTS

The registry included 1663 patients (advanced GIST, n=1095; localised GIST, n=537). Medications (e.g. tyrosine kinase inhibitor use and dosing), disease progression or recurrence and physician assessment of response to treatment in registry patients were consistent with controlled trials and prevailing clinical recommendations. In advanced GIST, estimated 30-month progression-free survival (PFS) (59.8%) and overall survival (OS) (82.7%) were higher than results from previously reported trials (≈40% and ≈70%, respectively). Consistent with treatment guidelines, the most common initial treatments were imatinib for advanced GIST, and complete surgical resection for localised GIST. Computed tomography scans were the most common imaging technique used at diagnosis and follow-up. Mutation analysis was performed at diagnosis in only 15.3% and 14.5% of patients with advanced and localised GIST, respectively.

CONCLUSIONS

In this real-world GIST registry, patients with advanced GIST were treated with imatinib and patients with localised GIST received surgical resection, in accordance with prevailing clinical recommendations.

SLITRK3 expression correlation to gastrointestinal stromal tumor risk rating and prognosis

AIM: To assess the influence of SLIT and NTRK-like family member 3 (SLITRK3) on the prognosis of gastrointestinal stromal tumor (GIST) and determine whether SLITRK3 can help improve current risk stratification systems.

METHODS: We hypothesized that SLITRK3 could be used as a prognostic molecular biomarker for GIST. 35 fresh tumor samples and 417 paraffin-embedded specimens from GIST patients were utilized. SLITRK3 mRNA expression in GIST tumor tissue was detected by real-time polymerase chain reaction, and SLITRK3 protein levels were estimated by immunohistochemistry. The correlation of SLITRK3 expression with various tumor clinicopathological characteristics and follow-up data were analyzed.

RESULTS: GIST tumors had high expression of SLITRK3 compared with adjacent normal tissues and the expression level gradually increased with risk grade. SLITRK3 protein expression was closely associated with gastrointestinal bleeding, tumor site, tumor size, mitotic index, and National Institutes of Health (NIH) classification. Survival analysis showed that SLITRK3 expression was closely correlated with overall survival and disease-free survival of GIST patients. Multivariate analysis also identified SLITRK3 expression, mitotic index, and NIH stage as significant risk factors of GIST recurrence.

CONCLUSION: SLITRK3 expression is a highly significant predictor of GIST recurrence and metastasis. Combinations of SLITRK3 and NIH stage have strong predictive and prognostic value, and are feasible markers for clinical practice in gastrointestinal stromal tumor.

Treatment and Prognoses in Patients With Primary Gastrointestinal Stromal Tumors ≥10 cm: A Single-Institution Experience in China

Data on treatments and specific outcomes of primary gastrointestinal stromal tumors (GISTs) ≥10  cm are limited. We here report the treatments and survival outcomes concerning a subgroup of primary giant GISTs. Data of 83 consecutive patients with primary GISTs ≥10  cm in a single institution were retrospectively collected. Fifty-eight patients underwent surgery before imatinib mesylate (IM) treatment (Group A), 10 underwent surgical resection following IM therapy (Group B), whereas 15 patients took IM as drug therapy alone (Group C). The baseline clinical characteristics were similar among the 3 groups. However, a lower proportion in Group A had metastatic disease at the time of diagnosis or surgery compared with Groups B and C (8.6% vs 40.0% vs 40.0%, P < 0.05). The median follow-up duration was 21.5 months. No statistically significant differences were observed on progression-free survival (PFS) among the groups. However, patients in Group B showed significantly better overall survival (OS) compared with those in Group C (P = 0.044). Multivariate analysis showed that patients treated with adjuvant IM were associated with better PFS (hazard ratio [HR] 3.01; 95% confidence interval [CI] 1.13-7.97; P = 0.027) and OS (HR 29.11; 95% CI 3.32-125.36; P = 0.004). The subgroup with mitotic count >10/50 high-power fields (HPF) showed worse PFS (HR 3.50; 95% CI 1.19-10.25; P = 0.022) and OS (HR 20.04; 95% CI 1.67-143.79; P = 0.018) than that of mitotic count ≤5/50 HPF. Clinical treatment patterns for primary giant GISTs are different, and the outcomes of different interventions vary. The optimal treatments for these subgroup of patients still require further long-term investigation. Moreover, mitotic count and adjuvant IM are closely associated with PFS and OS in giant GISTs.

Duodenal gastrointestinal stromal tumor: From clinicopathological features to surgical outcomes

Duodenal gastrointestinal tumors represent an extremely rare subset of stromal tumors arising from interstitial cells of Cajal. In the last 30 years the comprehension of the pathophysiology and natural history of this previously misunderstood clinical entity, in association with developments in endoscopy, imaging technology, and immunohistochemistry has resulted in novel diagnostic and treatment approaches. This is a comprehensive review of the current data of the literature on the various aspects of the diagnosis and treatment of these tumors. The duodenum is the less commonly involved site for these tumors in the digestive tract. Endoscopy and computed tomography can usually establish the diagnosis, confirmed by immunohistochemical staining and occasionally molecular genetic analysis. Endoscopic ultrasound with fine needle aspiration has been recently found to be the gold diagnostic standard with high sensitivity and specificity rates, diagnosing GIST in up to 80% of patients. Due to the complex anatomy of the pancreatico-duodenal region optimal therapeutic strategy of duodenal GISTs are challenging. Nevertheless surgical resection with microscopically clear resection margins seems to be the only potentially curative treatment for non-metastatic primary GISTs of the duodenum. Imatinib mesylate plays a key role in the management of GISTs both as neoadjuvant therapy and in patients with recurrent and metastatic disease. Meanwhile, the advances in the comprehension of the pathophysiology and natural history of this previously misunderstood clinical entity as well as the treatment of these tumors may render feasible, in the near future, the advent of newer and more effective treatment options.

Prognostic angiogenic markers (endoglin, VEGF, CD31) and tumor cell proliferation (Ki67) for gastrointestinal stromal tumors

AIM: To evaluate the correlation between the immunoexpression of angiogenic markers [CD31, CD105 and vascular endothelial growth factor (VEGF)], proliferative index (Ki67), and prognosis of patients with gastrointestinal stromal tumors (GIST).

METHODS: This is a retrospective study of 54 GIST cases. Medical records were searched to obtain the GIST patients’ demographic and clinical data, and paraffin-embedded blocks of tumor samples were retrieved from the hospital archives to conduct a new immunohistochemical evaluation. The tumor samples of GIST patients were subject to immunohistochemical evaluation for endoglin (CD105), CD31, VEGF, and Ki67 expression. The CD105 and CD31 intratumoral microvascular density (IMVD) was measured using automated analysis. We determined the correlation between the immunoexpression of CD105, CD31, VEGF, Ki67 and prognosis. In addition, we conducted a cutoff analysis using the receiver-operating characteristic curve. VEGF positivity was classified as either null/weak or strong. Ki67 was evaluated using a cutoff of 5% positive cells. The prognosis was classified as good (patient alive without recurrence) or poor (patient with recurrence/death).

RESULTS: The distribution of tumor sites among the 54 analyzed samples was as follows: 27 (50%) in the stomach, 20 (37.1%) in the small intestine, 6 (11.1%) in the colon, and 1 (1.8%) in the esophagus. The size of the tumors ranged from 2 to 33 cm (median: 8 cm); in 12 cases (22.2%), the tumor was below 5 cm at the largest diameter, but in 42 cases (77.7%), the tumor was larger than 5 cm. The means of CD105 and CD31 were significantly higher in the group with poor prognosis (P < 0.001). The cut-off values of CD105 (> 1.2%) and CD31 (> 2.5%) in the receiver-operating characteristic curve were related to a poorer prognosis. Cases with a better prognosis showed significantly null/weak staining for VEGF (P < 0.001). Ki-67 expression of ≥ 5% was strongly correlated with a worse prognosis (P < 0.001). In the multivariate analysis, CD105 was the variable that most strongly correlated with prognosis.

CONCLUSION: The IMVD cutoff values for the angiogenic markers CD105 and CD31, may be prognostic factors for GIST, in addition to VEGF and Ki67.

Key Issues in the Clinical Management of Gastrointestinal Stromal Tumors: An Expert Discussion

After the revelation of kinase targeting with orally available small molecules, the use of imatinib in chronic myelogenous leukemia and in gastrointestinal stromal tumor (GIST) has now become commonplace and just two of many examples of the use of kinase inhibitors in cancer. In this article, we discuss important practice points that may impact upon questions of therapy of primary and metastatic GIST, with the hope that the questions addressed in this rare solid tumor can serve as examples of what can be achieved with kinase-directed therapies in other cancers. We present cases that highlight some of the key issues in GIST management and afterward discuss both points of consensus and controversial issues in what is now recognized as one of the most common forms of sarcoma.

IMPLICATIONS FOR PRACTICE

The treatment of gastrointestinal stromal tumor (GIST) has become sophisticated with the availability of three approved agents in many countries and 15 years of experience with primary and metastatic disease. Important lessons from tyrosine-kinase inhibitors in GIST can be gleaned from this experience and will impact implementation of similar agents for other cancers.

[A case of transcatheter arterial embolization for reduction of a hemorrhagic rectal gastrointestinal stromal tumor]

A 91-year-old woman was referred to our hospital with a primary complaint of hematochezia. A rectal submucosal tumor and an acute hemorrhagic rectal ulcer were noted on colonoscopy. After hemostasis was achieved with APC, the patient was diagnosed with a GIST by EUS-FNA. We performed TAE of the middle and inferior rectal artery to secure hemostasis, because these arteries were also observed to be bleeding during hospitalization. A CT scan and colonoscopy revealed that the rectal GIST had reduced and that the acute rectal ulcer had been successfully treated. We report a case in which TAE was used to achieve tumor reduction of a hemorrhagic rectal GIST.

Adherence to Guidelines for Adjuvant Imatinib Therapy for GIST: A Multi-institutional Analysis

BACKGROUND

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. Adjuvant imatinib therapy improves recurrence-free and overall survival following surgery for patients with high-risk GIST; however, the factors associated with use of adjuvant imatinib therapy are unclear, and adherence to adjuvant imatinib has not been investigated. We sought to determine the clinicopathologic predictors of therapy with adjuvant imatinib following surgical resection for GIST and to determine the utilization of adjuvant imatinib in patients who underwent surgical resection of primary GIST in 2009 or later as recommended by National Comprehensive Cancer network (NCCN) guidelines.

METHODS

A multi-institutional cohort including 171 patients who underwent surgery for primary GIST at seven high-volume cancer centers in the USA and Canada between January 2009-December 2012 was used in this study. Receipt of adjuvant imatinib therapy was ascertained, and factors associated with imatinib therapy were analyzed.

RESULTS

Following surgery for primary GIST, tumor size (<5.0 cm: ref; 5.0-9.9 cm: odds ratio (OR) 2.36, 95 % confidence interval (CI) 0.74-7.55; >10.0 cm: OR 9.15, 95 % CI 2.28-36.75; p = 0.007), mitotic rate (≤5/50 mitoses per 50 high powered field [HPF]: ref; 6-10/50 HPF: OR 24.91, 95 % CI 3.64-170.35; >10/50 HPF: OR 5.80, 95 % CI 3.64-170.35; p < 0.001), and neoadjuvant therapy (OR 9.52; 95 % CI 2.51-36.14; p = 0.001) were associated with receipt of adjuvant imatinib therapy. Overall, 75 % of patients received appropriate treatment, 23 % of patients were undertreated, and 2 % of patients were overtreated as compared to NCCN guidelines. Adjuvant imatinib therapy was administered in only 53 % of patients for which the NCCN guidelines recommended adjuvant therapy.

CONCLUSION

The clinicopathologic factors associated with use of adjuvant imatinib therapy in patients following resection of primary GIST are consistent with established risk factors for recurrence. Adjuvant imatinib therapy remains underutilized in patients with intermediate and high-risk GIST and in patients who receive neoadjuvant therapy. Barriers to adjuvant imatinib therapy in this group of patients needs to be further explored.

GIST treatment options after tyrosine kinase inhibitors

OPINION STATEMENT

The management of advanced gastrointestinal stromal tumor (GIST) has been dramatically altered by the development of tyrosine kinase inhibitors. The disease, which had a median overall survival of 12 months for patients with unresectable disease, now has a median survival approaching 5 or more years. The challenge faced clinically is how to care for patients when they have progressed on all approved therapies. Clinical trials evaluating the role of novel combination therapies with investigational agents that target AKT/PI3K pathways are of interest especially given the preclinical rationale available. The addition of an mTOR inhibitor can be tried as these are available, but requires care and monitoring for additional toxicities. With improved understanding of this disease, which we thought of as one biology, personalized therapies are being studied and tested and is particularly relevant for GIST that are less responsive to the standard kinase inhibitors, such as platelet-derived growth factor alpha (PDGFRA) D842V and wild-type/succinate dehydrogenase (SDH)-deficient GIST. IGF1R inhibitors as a class are not being developed because of the lack of significant efficacy in many clinical trials and the efficacy in WT GIST has been limited; to date drugs targeting VEGFR, such as sunitinib and regorafenib, appear to be the best agents available for this group of patients. The exciting findings seen with CTLA4 and PD-1/PD-L1 antibodies in melanoma and other solid tumors is exciting, especially because there is a growing body of evidence that such approaches have biologic rationale; clinical trials evaluating these agents are awaited with interest. Last, recent work has shed light on older agents that may have a role in GIST. Moving forward to test these agents alone or in combination with TKIs offers potentially new strategies for treating advanced disease.

Bone metastasis in gastrointestinal stromal tumors preferentially occurs in patients with original tumors in sites other than the stomach

Bone metastases are rare in gastrointestinal stromal tumors (GISTs) and data on the clinicopathological profiles are lacking. The purpose of this report was to identify the clinicopathological profiles of this rare clinical setting by evaluating 23 cases, four of which were our own and the additional 19 were from the relevant English literature. In 18 cases, the primary GISTs occurred in sites other than the stomach, although a high proportion of these tumors do arise in the stomach. All tumors at the disease presentation had more than a low risk of recurrence, with most tumors either at a high risk or initially malignant with liver metastasis. In four cases, bone metastasis was the primary metastatic manifestation. Although rare in GISTs, bone metastasis should be considered in patients with primary tumors at a high risk for recurrence or in initially malignant tumors with liver metastasis, especially with primary tumors in sites other than the stomach.

Primary gastrointestinal stromal tumor of the liver treated with sequential therapy

A 67-year-old female presented with a primary hepatic gastrointestinal stromal tumor that was detected by computed tomography and diagnosed based on histopathological and genetic analyses. The tumor was microscopically composed of spindle cells and epithelioid cells, and immunohistochemistry results showed positive staining for CD117 and CD34 expression. A genetic analysis revealed a heterozygous point mutation and deletion in exon 11 of c-KIT. After an R0 resection, imatinib mesylate was administered for 1 year until its use was discontinued due to severe side effects. Two years after the original operation, the tumor recurred in the residual liver and was completely resected again. Imatinib mesylate was administered for 2 years until it was replaced by sunitinib malate because of disease progression. The patient has survived for 53 mo after undergoing a sequential therapy consisting of surgical excision, imatinib and sunitinib.

Retrospective analysis of extra-gastrointestinal stromal tumors

AIM: To investigate the clinicopathologic features of patients with extra-gastrointestinal stromal tumors (EGISTs) in South Korea.

METHODS: A total of 51 patients with an EGIST were identified. The clinicopathologic features, including sex, age, location, tumor size, histology, mitotic rate, immunohistochemical features, genetic status and survival data, were analyzed.

RESULTS: The median age was 55 years (range: 29-80 years), and male:female ratio was 1:1.04. The most common site was in the mesentery (n = 15) followed by the retroperitoneum (n = 13) and omentum (n = 8). The median tumor size was 9.0 cm (range: 2.6-30.0 cm) and the median mitotic rate was 5.0/50HPF. (1/50 - 185/50). KIT was analyzed in 16, which revealed 10 cases with wild-type KIT and 6 cases with an exon 11 mutation. Among 51 patients, 31 patients had undergone surgery, and 10 had unresectable disease and had taken palliative imatinib, which resulted in 22.7 mo of progression-free survival. Of the patients who had undergone surgery, 18 did not take adjuvant imatinib, and 8 of these were categorized as “high risk” according to the risk criteria. However, the relapse-free survival was not different (P = 0.157) between two groups.

CONCLUSION: Because the biologic behaviors of GISTs differ according to the location of the tumor, a more stratified strategy is required for managing EGISTs including incorporation of molecular features.

Rapid-onset opioids for the treatment of breakthrough cancer pain: two cases of drug abuse

SETTING

In the last few years, the use of opioids for cancer pain has rapidly increased and new molecules have been developed. Currently, rapid-onset opioids are widely used in clinical practice for breakthrough cancer pain (BTcP). However, the tolerability of these molecules is still a matter of debate.

PATIENTS

We describe two cases of rapid-onset opioids misuse that have been recently observed at our palliative care unit.

DISCUSSION

The reported cases are explicative as they occurred in patients suffering from different types of cancer and with different causes of BTcP. Further investigations are needed to identify factors predicting addiction to this new class of molecules.

Giant gastrointestinal stromal tumor of the stomach: a challenging diagnostic and therapeutically approach

Gastrointestinal stromal tumors (GISTs) are rare but challenging tumors regarding the diagnosis and therapy. The symptomatology depends on the tumor size and location, and can be totally non-specific, as in the present case. We present the case of a 76-year-old female that was hospitalized with postprandial nausea and vomiting. Bulging of the posterior wall of the stomach was seen at endoscopically examination and confirmed by the computed tomography. Surgical resection of the 120×100 mm-sized tumor that involved the posterior gastric wall and gastrocolic ligament, was performed; the posterior wall of the stomach was also partially excised. Histological examination revealed a 120×95×70 mm nodular tumor with solid aspect and large necrotic and hemorrhagic area on cut section. The tumor cells were marked by c-KIT, DOG-1, smooth muscle actin and MSH-2 and were negative for Ki67, maspin, E-cadherin, S-100, and keratin AE1÷AE3. The resection margins were free of tumor cells. No recurrences were reported three years after surgical intervention; no postoperative chemotherapy was performed. This case highlights that a well-conducted trans-disciplinary approach can have real benefits, even in borderline-operable giant potentially-malignant GISTs. New criteria to establish the malignant potential of GIST should be explored.

Giant gastrointestinal stromal tumor of the stomach

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal malignancies of the digestive tract. Gastric localization is the most frequent. The aim of this study is to evaluate the importance of immunohistochemical factors (CD117, CD34, α-SMA, vimentin, p53, Ki67) in diagnostic and size tumor and mitotic activity as prognostic factors for these tumors. We present the case of a 66-year-old male patient with a giant gastric GIST. Like in the vast majority, the symptomatology in this patient has long been faint, despite the large tumor size, and when it became manifest, it was nonspecific. Imagery wise, the computer tomography (CT) scan was the most efficient, showing the origin of the tumor from the greater curvature of the stomach, its dimensions, as well as the relations with the other abdominal viscera. Surgery in this patient was en-bloc, according to the principles of GIST. The histological aspect is characterized by a proliferation of spindle cells positive for CD117 and CD34. Despite complete microscopic resection, the size of the tumor (25×20×27 cm) and the mitotic activity (21÷5 mm2) remains important relapse factor.

Survival in patients with hypoechoic muscularis propria lesions suggestive of gastrointestinal stromal tumors in gastric wall

BACKGROUND

Subepithelial lesions (SEL) on upper gastrointestinal endoscopy are frequently encountered and referred to endoscopic ultrasound (EUS). Management of small gastric hypoechoic SELs of muscularis propria (MP) is controversial since EUS-assisted fine needle aspiration may be inconclusive, and surgical excision may be too invasive. We aimed to analyze our gastric MP-SELs in terms of survival and confounding factors.

METHODS

Data from gastric hypoechoic MP-SELs suggestive of gastrointestinal stromal tumor (GIST) by EUS were retrospectively reviewed. Surgically resected GISTs were stratified according to the current pathological risk criteria.

RESULTS

Sixty-one patients were identified. The mean age was 55.5 ± 13.2 years and 45.6% were male. Mean follow-up duration was 53.4 ± 26.7 (12-110) months. Twenty-eight (45.9%) patients were managed conservatively (diameter 15.3 ± 10.1 mm). There were no metastasis- or tumor-related deaths and no significant size changes (≥ 5 mm) in this group during follow-up. Thirty-three (54.1%) patients underwent complete resection (diameter 34.2 ± 14.1 mm) among which 25 (75.8%) had the final diagnosis of GIST; 2 (8.0%), 14 (56%) and 6 (24%) patients were classified in no-risk, very-low-risk, low-risk categories respectively, while 2 (8.0%) were in moderate-risk and only 1 (4.0%) was in high-risk category.

CONCLUSIONS

The excellent survival of patients with small hypoechoic gastric MP-SELs with conservative management represents indolent course of those lesions. We suggest re- consideration of the recommendations in the current guidelines towards extending the follow-up intervals for small MP-SELs.

Is gastrointestinal stromal tumor (GIST) originating from the rectovaginal septum GIST or extra-GIST (EGIST)? A case report with literature review

Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal (GI) tract that arise from primitive mesenchymal cells. Extragastrointestinal stromal tumors (EGISTs) are extremely rare tumors that show the features of GISTs outside the GI tract. Their most common locations are the omentum, mesentery, and retroperitoneum. The authors report herein a case of a 54-year-old woman with GIST in rectovaginal septum. The patient underwent low anterior resection of the rectum, total abdominal hysterectomy, bilateral salpingo-oophorectomy, and partial resection of the posterior vagina. She received adjuvant therapy with an oral tyrosine-kinase inhibitor. She is presently healthy without any evidence of recurrence at 26 months after surgery. For GISTs arising in the rectovaginal septum, it is difficult to ascertain whether the tumor origin site is the rectum, rectovaginal septum, or vagina. In other words, it is difficult to classify these tumors as GISTs or EGISTs. More consideration for the exact origin should be given to the GIST in the rectovaginal septum for the precise diagnosis (GIST or EGIST) and risk classification in future.

Synchronous poorly-differentiated neuroendocrine carcinoma and gastrointestinal stromal tumor of the stomach: a case report with immunohistochemical and molecular genetic analyses of KIT and PDGFRA

Although the stomach is the most common location for gastrointestinal stromal tumor (GIST) with co-primary tumors, the synchronous appearance of a poorly differentiated neuroendocrine carcinoma (NEC) and GIST in the stomach is extremely rare. To the best of our knowledge, this is the first case of gastric GIST coexisting with gastric NEC to be reported in the literature. The current study reports the case of a 71-year-old male with gastric poorly differentiated NEC and GIST discovered incidentally during surgical treatment of the NEC. Immunohistochemistry analysis showed that the NEC tumor cells were positive for CK (cytokeratin), CD57, synaptophysin, chromogranin, CD117 (KIT protein), Dog-1 (discovered on GIST-1 protein) and CD34. The synchronous GIST immunophenotype showed positivity for CD117, Dog-1 and CD34 (100%), whereas staining for CK, SMA, desmin and S100 was negative. Ki-67 labeling of proliferating cells was 90% in NEC and 1% in GIST. An accurate diagnosis was confirmed by immunohistochemical findings. Furthermore, genetic analysis using PCR direct sequencing identified no mutations in the KIT (exons 9, 11, 13 and 17) and PDGFRA (exons 12 and 18) genes. The patient developed lymph node metastases and underwent cisplatin-based chemotherapy after the operation. This is the first documented case of synchronous gastric GIST and NEC with the examination of protein expression and gene mutations in KIT and PDGFRA, which will help to further understand the etiology and pathogenesis of NEC coexisting with GIST in a gastric location.

Gastrointestinal stromal tumors: current translational research and management modalities

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. In recent years, detection of these subepithelial lesions has improved due to advances in endoscopic imaging techniques. Furthermore, developments in immunohistochemical technologies, allowing for reliable differentiation of GISTs from other subepithelial tumors, have improved the understanding of these lesions significantly. Alongside the emergence of these new technologies, clinical management of GISTs has progressed greatly in the last decade. However, major controversies still exist in various aspects of GIST management, such as diagnosis, treatment, and prognosis. This review article provides the current overview of the research status in the management of GISTs.

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy in sarcomatosis from gastrointestinal stromal tumor

The role of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) procedures in the management of patients with gastrointestinal stromal tumor (GIST)-induced sarcomatosis that is refractory to tyrosine kinase inhibitors (TKI) is not well defined. A retrospective analysis of a prospective database of 1070 CRS/HIPEC procedures was performed. Demographics, Eastern Cooperative Oncology Group performance status, resection status, morbidity, mortality, perioperative use of targeted therapies, and overall survival were analyzed. Since 1992, 18 CRS/HIPEC procedures were performed for peritoneal dissemination of GIST. Fifty per cent of these cases were performed before the introduction of TKIs. R0/1 resection was achieved in 72 per cent, whereas 63 per cent of patients were treated with neoadjuvant and/or adjuvant targeted therapy. Thirty-day morbidity and mortality were 33.3 and 5.6 per cent, respectively. Median overall survival after CRS/HIPEC was 3.33 years with 3-year survival of 56 per cent. Median survival in those who did not receive targeted therapy was 1.04 versus 7.9 years for those treated with TKI and cytoreduction. Median postsurgical survival for those treated preoperatively with progression on TKI treatment was 1.35 years versus not reached in those on TKI therapy without progression. Primary therapy for patients with disseminated GIST should be TKI therapy. However, in patients with sarcomatosis from GIST, cytoreduction should be considered before developing TKI resistance. Progression on TKI is associated with poor outcomes even after complete cytoreduction.

[Epidemiological, clinical features, therapeutic results and evolution of gastrointestinal stromal tumour: about 25 cases]

BACKGROUND

Gastrointestinal stromal tumors (GIST) are mesenchymal tumors occuring in the majority of cases in the stomach and small intestine, rarely in rectum, colon, esophagus or mesentery. They are derived from cells of cajal or their precursor, and are typically CD117/KIT + (95%), CD34 + (70%).

AIMS

is to study the epidemiological, clinical, therapeutic and evolution of gastrointestinal stromal tumors.

METHODS

retrospective study including all patients with the diagnosis of GIST supported in the department of gastroenterology and surgery in universital hospital of Monastir.

RESULTS

25 patients were included, 12 men and 13 women with an average age of 60.5 years. Digestive symptomatology was dominated by gastrointestinal bleeding (n = 12) and abdominal pain (n = 12). The tumor was discovered incidentally in two patients. The small intestine was the most common site of the tumor (n = 10), followed by the stomach in 9 patients, rectum in two patients, the colon (n = 1), the bulb of water (n = 1), duodenum (n = 1) and liver in a patient. The tumor size ranged from 0.8 to 24 cm. GIST was localized in 16 patients, in whom therapeutic care based mainly on surgery and optimal broad. It was metastatic in 9 patients, in whom treatment using imatinib as first-line in 4 of them with a good response in 3 patients and the possibility of R0 surgery in one patient, initial stabilization and then a secondary exhaust in a patient. The first surgery was necessary in 5 patients in complicated situation or if diagnostic doubt.

CONCLUSION

The best characterization of GIST thanks to advances in cancer research has led to improved treatment of these tumors. Surgery is the standard treatment in localized forms. Imatinib is the standard treatment in metastatic GIST first line as well as adjuvant after surgery.

Gastrointestinal stromal tumor of colon: a case report and review of literature

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal tract. GISTs originate from cells of Cajal and related stem cells. Surgery and imatinib therapy are the main lines of treatment.

CASE REPORT

We report on a case with GIST in the colon treated with surgical resection followed by adjuvant imatinib therapy. This treatment showed no side-effects, and subsequent colonoscopy was unremarkable.

CONCLUSION

The diagnosis was delayed for 12 months after initial presentation of vague abdominal pain, thus highlighting the need to improve clinical suspicion in order to detect GISTs in earlier stages when resection may be curative. Colonic GIST, in particular, may mimic presentation similar to ovarian cyst, as seen in the present case. This case report corroborates that patients with high-grade GISTs can be effectively treated with imatinib therapy. However, duration of treatment may vary depending on the grade of the tumor and side-effects.

Prognostic value of Ki67 index in gastrointestinal stromal tumors

BACKGROUND

Ki67 index is one of the most important immunocytochemical markers of proliferation in tumors, but the criterion of Ki67 index in GISTs was not well-defined yet. Our study aims to fully evaluate the prognostic value of Ki67 index in GIST patients and efficiency of imatinib adjuvant therapy.

METHODS

Clinicopathological data were confirmed by pathological diagnosis and clinical recorders. Recurrence-free survivals (RFS) were evaluated in 418 GIST patients (370 cases only taken the surgery and 48 high-risks taken imatinib adjuvant therapy after R0 resection).

RESULTS

Two cutoff levels of Ki67 index (>5 and >8%) were established in our study through statistical analysis. Ki67 index (≤5, 6-8 and >8%) is an independent prognostic factor for RFS of GIST patients. Ki67 index>8% can precisely sub-divide high-risk GISTs effectively with different outcomes, and high-risk patients with Ki67 index>8% showed a poorer prognosis even with imatinib adjuvant therapy.

CONCLUSION

Ki67 index is an effective complementation of modified NIH criteria in predicting the prognosis of GISTs, and Ki67 index>8% may act as an unfavorable factor for imatinib adjuvant therapy.

Tumors of the angle of Treitz: A single-center experience

AIM: To explore the feasibility and oncologic outcomes of segmental jejunal resection on the left side of the mesenteric vessels in patients with tumors of the angle of Treitz using data from a single center.

METHODS: Thirteen patients with tumors of the angle of Treitz who underwent surgery at our institution were prospectively followed. A segmental jejunal resection on the left side of the mesenteric vessels was performed in all patients. Formalin-fixed and paraffin-embedded tumor samples were examined. The primary end point of this analysis was disease-free survival.

RESULTS: In this study, there were 8 males and 5 females (mean age, 50.1 years; range, 36-74 years). The mean tumor size was 8.1 cm (range, 3.2-15 cm). Histologic examination showed 11 gastrointestinal stromal tumors (GISTs) and 2 adenocarcinomas. Five of the GIST patients presented with potential low risk, and 6 presented with intermediate and high risk, according to the National Institutes of Health criteria. One potentially high-risk patient showed tumor progression at 46 mo and died 52 mo after surgery. One patient with locally advanced adenocarcinoma received neoadjuvant chemotherapy and adjuvant radiotherapy, but the disease progressed, and the patient died 9 mo after surgery. One GIST patient without progression died 16 mo after surgery because of a postoperative intestinal obstruction. The median overall survival rate was 84.6 mo, and the median disease-free survival rate was 94.5 mo.

CONCLUSION: The overall survival of patients with tumors of the angle of Treitz was encouraging even when the tumor size was relatively large. A segmental resection on the left side of the mesenteric vessels is considered to be a reliable and curative option for tumors of the angle of Treitz.

[Diagnosis and treatment of wild-type gastrointestinal stromal tumors]

Gastrointestinal stromal tumors(GIST) are the most common mesenchymal tumors of the gastrointestinal tract, and are mostly characterized by c-kit or PDGFRA gain-of-function mutation. About 10%-15% of GIST do not harbor any mutations in the c-kit and PDGFRA genes and are defined as wild-type GIST. There are significant differences in molecular mechanism and clinical characteristics between wild-type GIST and mutant GIST. Wild-type GIST should be considered as a family of diseases due to their extreme heterogeneity. Clinician should pay close attention to the diagnosis and treatment of wild-type GIST.