Perspective on updated treatment guidelines for patients with gastrointestinal stromal tumors

USP5 Promotes Ripretinib Resistance in Gastrointestinal Stromal Tumors by MDH2 Deubiquition

Ripretinib, a broad-spectrum inhibitor of the KIT and PDGFRA receptor tyrosine kinases, is designated as a fourth-line treatment for gastrointestinal stromal tumor (GIST). It is tailored for patients resistant to imatinib, sunitinib, and regorafenib. As its increasing use, instances of resistance to ripretinib are becoming more frequent. Unfortunately, there are currently no scientifically mature treatment options available for patients resistant to ripretinib. Posttranslational modifications (PTMs) such as ubiquitination, in conjunction with its interplay with other modifications, play a collective role in regulating tumor initiation and progression. However, the specific association between ubiquitination and ripretinib resistance is not reported. Through proteome-ubiquitinome sequencing, increased levels of the USP5 protein and decreased ubiquitination in ripretinib-resistant GISTs are detected. Subsequent examination of the mass spectrometry findings validated the interaction through which TRIM21 governs USP5 expression via ubiquitination, and USP5 regulates MDH2 expression through deubiquitination, consequently fostering ripretinib resistance in GIST. Moreover, ZDHHC18 can palmitoylate MDH2, preventing its ubiquitination and further increasing its protein stability. The research underscores the correlation between posttranslational modifications, specifically ubiquitination, and drug resistance, emphasizing the potential of targeting the USP5-MDH2 axis to counteract ripretinib resistance in GIST.

Case report and literature review: patient with gastroduodenal intussusception due to the gastrointestinal stromal tumor of the lesser curvature of the gastric body

BACKGROUND

Intussusception in adult patient is rare. Gastroduodenal intussusception due to the gastrointestinal stromal tumors is infrequently described in the literature. Authors present a case of gastroduodenal intussusception due to the low-risk gastrointestinal stromal tumor of the lesser curvature of the gastric body with literature review.

CASE PRESENTATION

Sixty-two-year-old male was admitted to our hospital with symptoms of acute gastric outlet obstruction. Imaging studies confirmed a lesion of the gastric wall producing gastroduodenal intussusception with pylorus obstruction. Upon laparotomy a tumor mass of the lesser curvature of the gastric body that invaginated through the pylorus into the duodenum was found. Desinvagination and resection of the tumor with the adequate resection margins were performed. Histology reveled a low-risk gastrointestinal stromal tumor. Due to favorable outcome only observation was suggested by the multidisciplinary team.

CONCLUSIONS

Gastroduodenal intussusception due to the gastrointestinal stromal tumor of the gastric wall is a rare event. Surgical resection is the treatment of choice. In selected cases laparosopic resection of the tumor can be performed.

Predictive ability of prognostic nutritional index in surgically resected gastrointestinal stromal tumors: a propensity score matching analysis

Prognostic nutritional index was found to be correlated with prognosis in GISTs before and after propensity score matching and its incorporation improved the prognostic stratification of NIH risk criteria.

Rapidly progressive dyspnea in gastrointestinal stromal tumor (GIST) with imatinib cardiac toxicity

Gastrointestinal stromal tumors (GISTs) are rare and current estimates range from 4,000 to 6,000 number of GIST cases in the USA annually. Imatinib, a tyrosine kinase inhibitor, has shown a survival benefit in GISTs, and the presence of KIT mutation status is predictive of response. The current case discusses rapidly progressive dyspnea and heart failure in an elderly male with metastatic GIST who was started on imatinib. Although reported as a rare and sporadic side effect of imatinib, the current case illustrates rapidity and the clinical significance of cardiotoxicity, with onset at 2 weeks.

Cases of imatinib-induced cardiotoxicity can range from being mild ventricular dysfunction to overt heart failure. Prior to starting imatinib, our patient had a history of hypertension. He subsequently ended up developing heart failure as acknowledged by the echocardiogram (ECHO). In general, elderly with preexisting cardiovascular comorbidity are at greater risk. The goal in such situations is immediate discontinuation or reduction of the imatinib dosage. The case prompts for awareness of imatinib cardiotoxicity. Moreover, a pretreatment cardiac assessment along with monitoring throughout therapy is therefore advisable. Also, imatinib-induced cardiotoxicity should be differentiated from imatinib-associated fluid retention, in which ECHO findings can be normal. This case report raises the concern for accelerated cardiotoxicity profile of imatinib. Further prospective studies with multidisciplinary input are needed to establish this association further.

Current status of proteomics of soft tissue sarcomas

INTRODUCTION

Proteomics has been used in soft tissue sarcoma (STS) research in the attempts to improve the understanding of the disease background and develop novel clinical applications. Using various proteomics modalities, aberrant regulations of numerous intriguing proteins were identified in STSs, and the possible utilities of identified proteins as biomarkers or therapeutic targets have been explored. STS is an exceptionally diverse group of malignant diseases with highly complex molecular backgrounds and, therefore, an overview of the achievements and prospects of STS proteomics could enhance our knowledge of the possibilities and limitations of cancer proteomics. Areas covered: This review examines all STSs that have been examined using proteomics modalities, discussing unique aspects, limitations, and possible improvements of individual reports. To contribute to the current progress in cancer treatment development using novel anti-cancer drugs, proteomics plays a central role in linking cutting-edge technologies, application of proteogenomics, patient-derived cancer models, and biobanking system. Expert commentary: Therefore, proteomic-based STS research will be developed as an interdisciplinary science. STS proteomics will be further developed based on the interaction of oncologists with basic researchers in various fields, aimed at obtaining an enhanced understanding of the biology of the disease and achieving superior clinical outcomes for patients.

Gastrointestinal Stromal Tumors: A Clinicopathologic and Risk Stratification Study of 255 Cases from Pakistan and Review of Literature

PURPOSE

To describe the clinicopathological features of gastrointestinal stromal tumors (GIST) diagnosed in our section and to perform risk stratification of our cases by assigning them to specific risk categories and groups for disease progression based on proposals by Fletcher et al and Miettinen and Lasota.

MATERIALS AND RESULTS

We retrieved 255 cases of GIST diagnosed between 2003 and 2014. Over 59% were male. The age range was 16 to 83 years with a mean of 51 years. Over 70% occurred between 40 and 70 years of age. Average diameter of tumors was 10 cms. The stomach was the most common site accounting for about 40%. EGISTs constituted about 16%. On histologic examination, spindle cell morphology was seen in almost of 85% cases. CD117 was the most useful immunohistochemical antibody, positive in 98%. Risk stratification was possible for 220 cases. Based on Fletcher's consensus proposal, 62.3 gastric, 81.8% duodenal, 68% small intestinal, 72% colorectal and 89% EGISTs were assigned to the high risk category; while based on Miettinen and Lasota's algorithm, about 48% gastric, 100% duodenal, 76% small intestinal, 100% colorectal and 100% EGISTs in our study were associated with high risk for disease progression, tumor metastasis and tumor related death. Follow up was available in 95 patients; 26 were dead and 69 alive at follow up. Most of the patients who died had high risk disease and on average death occurred just a few months to a maximum of one to two years after initial surgical resection.

CONCLUSIONS

Epidemiological and morphologic findings in our study were similar to international published data. The majority of cases in our study belonged to the high risk category.

Incidental finding of GIST during obesity surgery

BACKGROUND

The purpose of this study was to review the incidence of incidental gastrointestinal stromal tumors (GISTs) in a cohort of morbidly obese patients undergoing laparoscopic sleeve gastrectomy (LSG) or Roux-en-Y gastric bypass (RYGB), analyzing surgery indication, morbidity, and follow-up data.

METHODS

All cases with incidental GISTs found were reviewed.

RESULTS

Two thousand six hundred three patients underwent obesity surgery founding a gastric GIST in eight patients (incidence 0.31 %). Mean tumor size was 7.65 mm (range 2.5-13 mm) with the majority of the lesions located in the fundus of the stomach. All lesions had negative resection margins. At a mean follow-up of 30 months, all patients were disease-free.

CONCLUSION

The long-term disease-free survival of 100 % in our study establishes laparoscopic wedge resection during RYGB and LSG as safe and effective in treating incidental gastric GISTs <2 cm.

Feasibility and Diagnostic Yield of Endoscopic Ultrasonography-Guided Fine Needle Biopsy With a New Core Biopsy Needle Device in Patients With Gastric Subepithelial Tumors

As treatment decisions for patients with gastric subepithelial tumors (SETs) largely depend on the histopathologic diagnosis, noninvasive and effective tissue acquisition methods are definitely required for proper management of gastric SETs. Recently, a new endoscopic ultrasonography-guided fine needle biopsy (EUS-FNB) device with ProCore reverse bevel technology was developed. We aimed to elucidate the feasibility and diagnostic yield of EUS-FNB with this new core biopsy needle device in patients with gastric SETs. A prospectively maintained database was retrospectively reviewed to identify consecutive patients who underwent EUS-FNB with a 22-gauge ProCore needle for gastric SETs 2 cm or larger. The main outcome measurement was the diagnostic yield of EUS-FNB. Procedure results were categorized into diagnostic, suggestive, or nondiagnostic. Of the 43 patients, needle punctures were successful in all cases irrespective of tumor location. EUS-FNB procedure results were diagnostic in 86.0%, suggestive in 4.7%, and nondiagnostic in 9.3% of cases, respectively. The diagnostic yield was the highest in fundus (100.0%), followed by body (89.5%), cardia (83.3%), and antrum (50.0%). All 18 patients with cardiac SET were finally diagnosed to have leiomyoma, and 16 patients with diagnostic or suggestive results avoided surgery. A heterogeneous echo pattern on EUS was found in 33.3% of cases with nondiagnostic or suggestive results and in 5.4% with diagnostic results. In multivariate analysis, no independent predictor of unsuccessful EUS-FNB with nondiagnostic or suggestive results was identified. Agreement between EUS-FNB and surgical pathology was 100% with respect to the diagnosis of gastrointestinal stromal tumor. However, there was a significant discrepancy in mitotic counts observed between the EUS-FNB and surgical specimens in patients with gastrointestinal stromal tumor. There were no significant procedure-related adverse events during and after the procedures. EUS-FNB with a 22G ProCore needle is a technically feasible, safe, and effective procedure for pathologic diagnosis of gastric SETs. This procedure can help refine surgical indications and facilitate a proper treatment decisions for gastric SETs, especially in the cardia.

Histopathological Features of Gastrointestinal Stromal Tumors and the Contribution of DOG1 Expression to the Diagnosis

BACKGROUND

Gastrointestinal stromal tumors (GIST) have KIT or platelet-derived growth factor receptor α (PDGFRα) mutations affecting receptor tyrosine kinase activity and do not benefit from classic treatment regimens.

AIMS

The aim of this study was to review the algorithm that may be followed for the diagnosis and differential diagnosis in GISTs by investigating the histomorphological parameters and expression characteristics of classical immunohistochemical antibodies used in routine tests in addition to DOG1 expression.

STUDY DESIGN

Diagnostic accuracy study.

METHODS

We reevaluated the histological and immunohistochemical parameters of 37 GISTs. The standard immunohistochemical diagnosis and differential diagnosis panel antibodies (CD117, PDGFRα, CD34, vimentin, desmin, SMA, S-100, and Ki67) were studied on the tumor sections. We also used the popular marker DOG1 antibody with accepted sensitivity for GISTs in recent years and the PDGFRα immune marker for which the benefit in routine practice is discussed.

RESULTS

Classification according to progressive disease risk groups of the 37 cases revealed that 54% were in the high risk, 19% in the moderate risk, 16% in the low risk, 8% in the very low risk and 8% in the no risk group. Cytological atypia, necrosis, mucosal invasion and the Ki67 index were found to be related to the progressive disease risk groups of the tumors (p<0.05). Positive immunoreaction was observed with CD117 and PDGFRα in all GISTs in the study (100%). Positivity with the DOG1 antibody was found in 33 (89%) cases. CD34 was positive in 62% (23) of the cases.

CONCLUSION

The CD117 antibody still plays a key role in GIST diagnosis. However, the use of DOG1 and PDGFRα antibodies combined with CD117 as sensitive markers can be beneficial.

Clinicopathologic analysis of gastrointestinal stromal tumors in duodenum and small intestine

BACKGROUND

The prognosis about duodenal GISTs is debatable. The purpose of this study is to compare the characteristics and the prognostic factors in patients with gastrointestinal stromal tumor (GIST) located in the duodenum with those located in the small intestine.

METHODS

One hundred-one patients with GIST located in the duodenum (n = 40), or small intestine (n = 61) underwent resection between 1996 and 2010. We analyzed clinicopathologic features, surgical outcomes, and prognostic factors.

RESULTS

Five-year survival rate in patients with GIST located in the duodenum and small intestine were 66.6 and 80.8%, respectively (p = 0.018). After survival analysis, high mitotic count and tumor rupture were identified as independent adverse prognostic factors. Advanced T stage and absence of adjuvant imatinib treatment were adverse prognostic factors with marginal statistical significance. The rate of progressive disease was significantly higher in patients with duodenal GISTs (36.8%) than in those with small intestinal GIST (29.6%) (p = 0.024).

CONCLUSIONS

The clinicopathologic findings of duodenal GIST differ from those of small intestinal GIST. Patients with duodenal GIST have a worse prognosis than those with small intestinal GIST. Aggressive treatment including surgical resection should be considered for duodenal GIST, even if the risk is relatively low.

Gastrointestinal stromal tumors during pregnancy: a systematic review of an uncommon but treatable malignancy

Although modern social structure and medical advances have led to the increasing number of women childbearing in older age, cancer remains a rare diagnosis during pregnancy. There is little given information throughout the literature concerning gestation associated with the coexistence of gastrointestinal stromal tumor (GIST). In this review, we present 12 reported cases of GIST during pregnancy and we discuss the maternal and fetal outcome, as well as the therapeutic plan that was followed in each situation. From the collected data, 8 out of 12 cases had an uneventful outcome of their fetus. In 11 out of 12 cases surgical excision of the tumor was the treatment of choice, while seven women were treated with imatinib. Two of them were already on imatinib therapy during conception due to preexisting GIST diagnosis. Surgery remains the gold standard for the treatment of local or resectable GIST, while published data concerning the use of imatinib during pregnancy indicate that teratogenicity or fetal loss might be induced, especially if given during the first trimester of pregnancy. GIST during gestational period is a rare tumor in which a multidisciplinary approach should be designed, taking always into consideration that it has a favorable outcome on targeted treatment.

Preoperative predictive factors for gastrointestinal stromal tumors: analysis of 375 surgically resected gastric subepithelial tumors

BACKGROUND

Gastrointestinal stromal tumors (GISTs) and non-GIST subepithelial tumors (SETs) account for about 75 and 25% of gastric hypoechoic SETs ≥2 cm, respectively. Therefore, identifying preoperative predictive factors for GISTs are required to refine surgical indications.

METHODS

We performed a retrospective review of 375 surgically resected gastric hypoechoic SETs ≥2 cm. Demographic data and tumor characteristics based on upper endoscopy and CT findings were compared between GIST and non-GIST SETs originating from muscularis propria layer (leiomyomas, Schwannomas, glomus tumors, and ectopic pancreas).

RESULTS

In cardia, leiomyomas were found twice more frequently than GISTs (63.6 versus 31.8%). Perilesional lymph node enlargement (PLNE) was found only in patients with GIST or Schwannomas. Patients with GIST showed a significantly lower rate of PLNE than those with Schwannomas (3.5 versus 29.0%). In multivariate analysis, tumor site outside cardia (odds ratio, 9.157), absence of PLNE (odds ratio, 11.519), old age, large tumor size, exophytic growth pattern, and ulceration or dimpling were identified as independent preoperative predictive factors for GISTs versus non-GIST SETs.

CONCLUSIONS

The effort for preoperative pathologic diagnosis such as endosonography-guided tissue sampling might be positively considered for SETs at cardia and SETs with PLNE where the possibility of GIST is low.

Ligation-assisted endoscopic enucleation for the treatment of colorectal submucosal tumours originating in the muscularis propria

AIM

A ligation-assisted endoscopic enucleation (EE-L) technique was developed and was evaluated to determine its efficacy and safety for treating colorectal submucosal tumours (< 10 mm) originating in the muscularis propria.

METHOD

EE-L was used to treat 13 patients between January 2011 and January 2014. The tumour was sucked into a transparent cap and ligated at its base by a rubber band ligature attached to the tip of the endoscope. With the creation of a pseudo-stalk, the tumour was then enucleated using endoscopic dissection and the wound was closed with clips.

RESULTS

All tumours [median diameter 6.8 (4-10) mm] were successfully enucleated [procedure time 19 (11-27) min]. Histopathological examination identified 11 (84.6%) to be leiomyoma and 2 (15.4%) low-risk gastrointestinal stromal tumours. No perforations or massive haemorrhage occurred and there were no recurrences during a follow-up of 3-39 months.

CONCLUSION

EE-L is a successful technique for the removal of small colorectal tumours in the muscularis propria with few complications and enables a histopathological diagnosis. In this study, all the resected lesions had a benign pathology.

Endoscopic ultrasound-guided fine needle tissue acquisition biopsy samples do not allow a reliable proliferation assessment of gastrointestinal stromal tumours

BACKGROUND

Current prognostication of gastrointestinal stromal tumours is validated on/applies to resected tumours, mainly because surgery is recommended whenever possible. However, pre-treatment prognostication is increasingly warranted, considering the follow-up strategy recently admitted for expectedly low-risk tumours and the possible distinctive molecular features/spontaneous regression of some small cases.

AIMS

To investigate whether endoscopic ultrasound-guided fine-needle tissue acquisition-biopsies reflect prognosticators of resected gastrointestinal stromal tumours, for possibly developing reliable pre-treatment prognostic criteria.

METHODS

The applicability/reliability of mitotic index/5mm(2) and MIB1 proliferative index/1000 cells were tested in 35 endoscopic ultrasound-guided fine-needle tissue acquisition-biopsies diagnosed as gastrointestinal stromal tumour, subsequently resected without intervening therapy, consecutively collected in thirty months. Size and mitotic/proliferative indexes were compared with resection specimens. The feasibility of bioptic genotyping was also tested.

RESULTS

35 patients were studied (45.7% males; mean age 61.6 years, range 26-83 years). Mitotic/proliferative indexes were determinable in 68.6%/88.6% of biopsies, respectively; they were nevertheless underestimated, as happened with endoscopic ultrasound-determined tumour size. Bioptic genotyping revealed reliable.

CONCLUSIONS

Endoscopic ultrasound-guided fine-needle tissue acquisition does not reliably reflect gastrointestinal stromal tumours' proliferation and size. Alternative parameters should be validated for a pre-surgical prognostic classification. Considering the emerging potentially prognostic genetic markers in gastrointestinal stromal tumours, the reliability of bioptic genotyping is a promising result.

The economic burden of gastrointestinal stromal tumor (GIST) recurrence in patients who have received adjuvant imatinib therapy

OBJECTIVE

To estimate the economic burden of gastrointestinal stromal tumor (GIST) recurrence in patients who received imatinib adjuvant therapy.

METHODS

Data from the MarketScan and PharmMetrics databases between January 2000 and March 2013 were extracted. Patients who had received at least one diagnosis of GIST, had undergone a primary surgery for GIST, and had received at least one prescription for imatinib were included in the analysis. An algorithm was applied to identify those who had a subsequent GIST recurrence. Patients who experienced a recurrence and those who did not have a recurrence were compared for differences in healthcare utilization measures and healthcare costs within 6 months after the recurrence, while adjusting for potential confounding factors.

RESULTS

A total of 540 patients with primary resectable GIST who received imatinib adjuvant therapy were identified, including 444 (82.2%) patients who did not experience GIST recurrence and 96 (17.8%) patients who did experience recurrence. Patients who experienced GIST recurrence utilized significantly more healthcare resources in all categories than patients who did not have a recurrence, including the number of hospitalizations, days of hospitalization, emergency room visits, outpatient visits, and other medical services (all p-values <0.01). The total healthcare cost was significantly higher for patients with GIST recurrence, with a difference of $4464 per patient per month (p < 0.01). Both the medical and pharmacy costs were significantly higher with adjusted differences of $3488 and $1423 per patient per month, respectively (both p-values <0.01).

CONCLUSIONS

Patients who had GIST recurrence after surgical resection incurred significantly more healthcare resource utilization and greater healthcare costs within 6 months after the recurrence than patients who did not have recurrence. These findings suggest that GIST recurrence is associated with a substantial economic burden.

Endoscopic versus open resection for small gastric gastrointestinal stromal tumors: safety and outcomes

Endoscopic resection has been performed to treat small gastric neoplasms. However, this technique for small gastric gastrointestinal stromal tumors (GISTs) remains controversial. This study aims to compare the safety and surgical outcomes of endoscopic versus open resection of small gastric GISTs.The medical records of 54 consecutive gastric GISTs patients with tumor size of ≤2 cm, who were surgically treated with endoscopic resection (endoscopic group) or open surgery (laparotomy group) in a single institution from March 2010 to June 2014, were retrospectively analyzed. The clinical and tumor characteristics, surgical safety, and tumor-related outcomes were evaluated.Of 54 patients, 32 and 22 patients underwent endoscopic resection and laparotomy, respectively. Patients who underwent endoscopic resection yielded a significantly shorter hospital stay compared with patients who underwent laparotomy (P < 0.001). Compared with patients in the endoscopic group, patients in the laparotomy group had more intraoperative blood loss (P < 0.001), had longer nasogastric tube retention (P < 0.001), and required longer operative time (P < 0.001). More laparotomy patients required postoperative analgesic drugs than those in the endoscopic group (n = 9 vs 4; P = 0.016). Gastric perforation occurred in 1 case during operation in the endoscopic group. Patients who underwent these 2 procedures did not differ with respect to tumor size (P = 0.168), perioperative transfusion (P = 1.000), reoperation (P = 1.000), early satiety (P = 0.560), and postoperative bleeding (P = 1.000). With a median follow-up time of 34.5 months, 1 high-risk patient in each group experienced tumor recurrence/metastasis postoperatively.The endoscopic procedure allows safe resection with good surgical outcomes for small gastric GISTs compared with laparotomy. Moreover, larger randomized controlled trials are warranted to confirm endoscopic application for small gastric GISTs.

Drug repurposing identifies a synergistic combination therapy with imatinib mesylate for gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is a rare and therefore often neglected disease. Introduction of the kinase inhibitor imatinib mesylate radically improved the clinical response of patients with GIST; however, its effects are often short-lived, with GISTs demonstrating a median time-to-progression of approximately two years. Although many investigational drugs, approved first for other cancers, have been subsequently evaluated for the management of GIST, few have greatly affected the overall survival of patients with advanced disease. We employed a novel, focused, drug-repurposing effort for GIST, including imatinib mesylate-resistant GIST, evaluating a large library of FDA-approved drugs regardless of current indication. As a result of the drug-repurposing screen, we identified eight FDA-approved drugs, including fludarabine phosphate (F-AMP), that showed synergy with and/or overcame resistance to imatinib mesylate. F-AMP induces DNA damage, Annexin V, and caspase-3/7 activities as the cytotoxic effects on GIST cells, including imatinib mesylate-resistant GIST cells. F-AMP and imatinib mesylate combination treatment showed greater inhibition of GIST cell proliferation when compared with imatinib mesylate and F-AMP alone. Successful in vivo experiments confirmed the combination of imatinib mesylate with F-AMP enhanced the antitumor effects compared with imatinib mesylate alone. Our results identified F-AMP as a promising, repurposed drug therapy for the treatment of GISTs, with potential to be administered in combination with imatinib mesylate or for treatment of imatinib mesylate-refractory tumors.

Reintroduction of imatinib in GIST

PURPOSE

This review examines the clinical evidence showing that imatinib can be prescribed to treat recurrence or progression of gastrointestinal stromal tumors (GIST) in patients who interrupted first-line imatinib therapy in the adjuvant or advanced/metastatic setting.

METHODOLOGY

A literature search was performed in PubMed, Web of Knowledge, and Google using the following keywords: rechallenge/reinitiation/reintroduction + gastrointestinal + imatinib and rechallenge/reinitiation/reintroduction + imatinib.

RESULTS

The evidence indicates that the reintroduction of imatinib can benefit patients who experience GIST progression after interrupting treatment of advanced/metastatic disease, as well as patients who experience GIST recurrence after completing prescribed neoadjuvant and/or adjuvant therapy. Although reintroduction of imatinib may lead to suboptimal outcomes, as evidenced by higher rates of progressive disease compared to initial treatment, imatinib discontinuation does not appear to favor development of imatinib resistance, leaving dose escalation and third- or fourth-line imatinib treatment as viable options for patients.

CONCLUSION

Results indicate that after initial start and interruption of imatinib therapy, reintroduction of imatinib therapy is efficacious and provides continued survival benefit in patients with GIST.

Tumor markers in colorectal cancer, gastric cancer and gastrointestinal stromal cancers: European group on tumor markers 2014 guidelines update

Biomarkers currently play an important role in the detection and management of patients with several different types of gastrointestinal cancer, especially colorectal, gastric, gastro-oesophageal junction (GOJ) adenocarcinomas and gastrointestinal stromal tumors (GISTs). The aim of this article is to provide updated and evidence-based guidelines for the use of biomarkers in the different gastrointestinal malignancies. Recommended biomarkers for colorectal cancer include an immunochemical-based fecal occult blood test in screening asymptomatic subjects ≥50 years of age for neoplasia, serial CEA levels in postoperative surveillance of stage II and III patients who may be candidates for surgical resection or systemic therapy in the event of distant metastasis occurring, K-RAS mutation status for identifying patients with advanced disease likely to benefit from anti-EGFR therapeutic antibodies and microsatellite instability testing as a first-line screen for subjects with Lynch syndrome. In advanced gastric or GOJ cancers, measurement of HER2 is recommended in selecting patients for treatment with trastuzumab. For patients with suspected GIST, determination of KIT protein should be used as a diagnostic aid, while KIT mutational analysis may be used for treatment planning in patients with diagnosed GISTs.

Ligation-assisted endoscopic enucleation for treatment of esophageal subepithelial lesions originating from the muscularis propria: a preliminary study

An innovative ligation-assisted endoscopic enucleation (EE-L) technique was developed for the diagnosis and treatment of esophageal subepithelial lesions (smaller than 12 mm) originating from muscularis propria by combining endoscopic band ligation and endoscopic enucleation techniques. The aim of the study was to evaluate efficacy and safety of EE-L technique in the treatment of esophageal subepithelial lesions (smaller than 12 mm) originating from muscularis propria. Forty-seven esophageal subepithelial lesions (smaller than 12 mm) originating from the muscularis propria in 44 patients were treated with EE-L between September 2010 and September 2012. The lesion was first aspirated into the transparent cap attached to the tip of endoscope. The elastic band was then released around its base. The purpose of ligation was to force the lesion to assume a polypoid form with a pseudostalk. Endoscopic enucleation was then performed until the tumor was completely enucleated from muscularis propria using a hook knife and forceps. All tumors (median diameter: 8.2 ± 2.3 mm, range: 4-12 mm) were enucleated completely. Histopathology identified 45 tumors (95.7%) as leiomyoma, 2 (4.3%) tumors as gastrointestinal stromal tumor with very low risk. The mean time of the EE-L procedure was 12.5 ± 4.6 minutes (range: 6-23 minutes). Two patients experienced self-limiting, non-life-threatening hemorrhage after EE-L. No perforation and massive hemorrhage requiring further endoscopic or surgical intervention occurred. There were no recurrences during the 6-24 months follow-up period. EE-L offers the option of localized treatment of small esophageal muscularis propria tumors (smaller than 12 mm) with relatively few complications and low mortality, and provides the advantage of allowing a histopathological diagnosis. All the resected lesions in this study had a benign pathology.

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.

MiR-320a downregulation is associated with imatinib resistance in gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GIST) is one of the most common mesenchymal tumors of the gastrointestinal tract. Though imatinib improves the outcome, drug resistance remains the major problem for extending patient survival. Genetic mutation of the drug targets is the known mechanism for imatinib resistance. However, it cannot explain all of the phenomena of imatinib resistance, and numerous additional mechanisms have been proposed to account for imatinib resistance in various model systems. In this study, we applied the SYBR-green quantitative polymerase chain reaction-based array approach to screen the differentially expressed miRNAs between primary GIST patients and imatinib-resistant patients. The selected candidate miRNAs were validated in a cohort of 12 GIST patients. We found that low expression of miR-320a was correlated with short time to imatinib resistance, and proposed the potential mechanism of miR-320a for imatinib resistance.

Minimally invasive treatment of laparoscopic and endoscopic cooperative surgery for patients with gastric gastrointestinal stromal tumors

OBJECTIVE

To evaluate the feasibility and safety of laparoscopic and endoscopic cooperative surgery (LECS) for the treatment of gastric gastrointestinal stromal tumors (GISTs).

METHODS

We retrospectively reviewed the data of 69 consecutive patients who underwent LECS, including laparoscopy-assisted endoscopic resection (LAER) and endoscopy-assisted laparoscopic wedge resection (EAWR), for pathologically confirmed gastric GISTs of less than 5 cm in diameter from January 2006 to October 2012.

RESULTS

The tumor was located at the upper third of the stomach in 22 patients, the middle third in 38 and the lower third in nine, with a mean tumor size of 2.8 ± 1.6 cm. The operating time was 81.6 ± 31.8 min in the LAER group and 86.3 ± 28.5 min in the EAWR group (P = 0.776). Intraoperative blood loss was 29.8 ± 15.4 mL in the LAER group and 31.4 ± 11.6 mL in the EAWR group (P = 0.561). Most patients had a very low or low risk of tumor recurrence, while six had an intermediate risk of tumor recurrence. The mean length of postoperative hospital stay was 4.6 days. Only two patients had postoperative complications after LECS, both of whom were treated successfully without open surgery. During a median follow-up of 35 months, all patients were disease-free, with no tumor recurrence or metastases.

CONCLUSION

LECS is a minimally invasive and safe alternative approach which can achieve fast recovery and satisfactory short-term outcomes for appropriately selected patients with gastric GISTs.

Adherence to imatinib therapy in gastrointestinal stromal tumors and chronic myeloid leukemia

The number of anticancer drugs available in oral formulation has risen sharply in the past few years and this is expected to continue to increase over the next several decades. For patients, the convenience of self-administration constitutes a major benefit associated with oral therapy. For clinicians, however, the transition from parenteral to oral therapy has resulted in concerns about adherence to therapy, its monitoring, and its effects on clinical outcomes. Several studies have demonstrated that imatinib is effective at improving overall survival and/or recurrence-free survival in patients with gastrointestinal stromal tumors and chronic myeloid leukemia (primary and metastatic disease). Despite the survival benefit and the favorable toxicity profile of imatinib, however, adherence to imatinib remains poor. Herein, we review the evidence showing the effects of nonadherence on patient outcomes as well as data indicating that adherence to imatinib (and oral anticancer therapy in general) is suboptimal. We also highlight factors that may contribute to nonadherence and suggest key steps that can be implemented by the multidisciplinary medical team to overcome the daily challenges of adherence. Improving adherence to imatinib depends on open communication and comprehensive patient education. All of this is essential to maximize benefits from therapy and improve clinical outcomes for our patients.

Ligation-assisted endoscopic enucleation for the diagnosis and resection of small gastrointestinal tumors originating from the muscularis propria: a preliminary study

Background

Ligation-assisted endoscopic enucleation (EE-L) was developed for the pathological diagnosis and resection of small gastrointestinal tumors originating from the muscularis propria. The technique combines endoscopic band ligation and endoscopic enucleation. The aim of this study was to evaluate the efficacy and safety of EE-L in the diagnosis and resection of gastrointestinal tumors originating from the muscularis propria.

Methods

A total of 43 patients were eligible for inclusion in this study from June 2009 to June 2011. Endoscopic ligation was first performed to force the tumor to assume a polypoid form with a pseudostalk. EE-L was then performed until the tumor was completely enucleated from the muscularis propria. Wound closure was performed using clips and adhesive tissue.

Results

All 43 tumors were completely enucleated. The mean enucleation time was 7.2 minutes (range, 5–11 minutes). No perforation, massive hemorrhage, or peritonitis requiring further endoscopic or surgical intervention occurred. Histopathology, 19 lesions were identified as gastrointestinal stromal tumors and 24 lesions were identified as leiomyomas. The mean follow-up time was 20.4 months (range, 14–38 months). No recurrence has occurred during the follow-up period.

Conclusions

EE-L appears to be a safe, effective, and relatively simple method for the histologic diagnosis and removal of small gastrointestinal tumors originating from the muscularis propria.

Companion biomarkers: paving the pathway to personalized treatment for cancer

BACKGROUND

Companion biomarkers are biomarkers that are used in combination with specific therapies and that prospectively help predict likely response or severe toxicity. In this article we review the role of companion biomarkers in guiding treatment in patients with cancer.

CONTENT

In addition to the established companion biomarkers such as estrogen receptors and HER2 (human epidermal growth factor receptor 2) in breast cancer, several new companion biomarkers have become available in recent years. These include v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations for the selection of patients with advanced colorectal cancer who are unlikely to benefit from anti-epidermal growth factor receptor antibodies (cetuximab or panitumumab), epidermal growth factor receptor (EGFR) mutations for selecting patients with advanced non-small cell lung cancer (NSCLC) for treatment with tyrosine kinase inhibitors (gefitinib or erlotinib), v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations for selecting patients with advanced melanoma for treatment with anti-BRAF agents (vemurafenib and dabrafenib), and anaplastic lymphoma receptor tyrosine kinase (ALK) translocations for identifying patients with NSCLC likely to benefit from crizotinib.

SUMMARY

The availability of companion biomarkers should improve drug efficacy, decrease toxicity, and lead to a more individualized approach to cancer treatment.

Drug repurposing for gastrointestinal stromal tumor

Despite significant treatment advances over the past decade, metastatic gastrointestinal stromal tumor (GIST) remains largely incurable. Rare diseases, such as GIST, individually affect small groups of patients but collectively are estimated to affect 25 to 30 million people in the United States alone. Given the costs associated with the discovery, development, and registration of new drugs, orphan diseases such as GIST are often not pursued by mainstream pharmaceutical companies. As a result, "drug repurposing" or "repositioning," has emerged as an alternative to the traditional drug development process. In this study, we screened 796 U.S. Food and Drug Administration (FDA)-approved drugs and found that two of these compounds, auranofin (Ridaura) and fludarabine phosphate, effectively and selectively inhibited the proliferation of GISTs, including imatinib-resistant cells. One of the most notable drug hits, auranofin, an oral, gold-containing agent approved by the FDA in 1985 for the treatment of rheumatoid arthritis, was found to inhibit thioredoxin reductase activity and induce reactive oxygen species (ROS) production, leading to dramatic inhibition of GIST cell growth and viability. Importantly, the anticancer activity associated with auranofin was independent of imatinib-resistant status, but was closely related to the endogenous and inducible levels of ROS. Coupled with the fact that auranofin has an established safety profile in patients, these findings suggest for the first time that auranofin may have clinical benefit for patients with GIST, particularly in those suffering from imatinib-resistant and recurrent forms of this disease.

Gastrointestinal Stromal Tumours: Review of 150 Cases from a Single Centre

Gastrointestinal stromal tumours (GIST) are the most common mesenchymal tumours of the gastrointestinal tract. They constitute a significant percentage ranging from 1-2 % of all the gastrointestinal neoplasms [11]. Knowledge on the molecular biology and behavior of these tumours is still not very clear. The clinicopathologial features are variable and surgical resection with chemotherapy is the main modality of treatment. We have retrospectively analyzed the clinicopathological features, treatment and prognosis of 150 patients managed in the Department of Surgery. Retrospective review of the records of 150 patients diagnosed with gastrointestinal stromal tumours and managed during the period January 2006 to December 2011. Clinicopathological features, immunohistochemistry, mitotic index, surgical resection adjuvant chemotherapy and survival analyzed. One hundred and fifty patients diagnosed with GIST and treated were reviewed. Ninety five of them were males (63.3 %). The tumour was most commonly seen during the fourth and fifth decades of life. Abdominal pain (52 %), intestinal bleeding (40 %) and abdominal mass (25 %) were the common clinical symptoms. Sixty percent of the tumours (90/150) were located in the stomach followed by small bowel (20 %) and duodenum (14.6 %). One hundred and thirty-five patients underwent excision of the tumour and five patients had multi organ resection of the adjacent organs like spleen, tail of the pancreas and kidney. Fifteen patients (10 %) received neoadjuvant Imatinib for down staging of the tumour prior to surgery. The tumour size ranged from 1 to 34 cm. One third of the tumours (42/150) belonged to the high-grade category. KIT protein (CD117) was positive in 90 %( 135/150), while CD34 was positive in 50 % (74/150) of tumours. Majority of the patients with high and intermediate-risk category received adjuvant Imatinib (65/77). Seventeen patients (11.3 %) developed recurrence of the tumour on follow-up and rest of the patients had stable disease. Eight of the 15 patients (53 %) who had advanced disease developed recurrence of the disease over 6 months to 1 year. Fifteen patients died on follow-up between 2 and 5 years. Gastrointestinal tumours are the most common non epithelial tumour of the GIT. GISTS are found to show a male preponderance and are common during the fourth and fifth decades. Abdominal pain and intestinal bleeding are the most common clinical presentation. Most of the tumours were located in the stomach. Surgical resection is the best modality of treatment for operable lesions. Tyrosine kinase receptor (KIT) inhibitor like imatinib is used for adjuvant treatment. Regular follow-up with ultra sonogram or computed tomogram helps in diagnosing disease recurrence.

An elective combined caesarean section and small bowel GIST resection during the third trimester of pregnancy: Report of a case

INTRODUCTION

Gastro-Intestinal Stromal Tumours (GISTs) are rare with an estimated incidence of only 11-15 per million. In pregnancy, GISTs are an extremely rare occurrence and are thus complex to manage from an ethical, surgical and oncological perspective.

PRESENTATION OF CASE

We present the first reported case in the literature of a successful combined lower segment caesarean section (LSCS) and a tumour resection in a 31-year-old pregnant patient presenting with a small bowel GIST.

DISCUSSION

We compare and contrast our case with other reported cases of GIST resection in pregnancy and discuss the challenges faced by both patients and clinicians.

CONCLUSION

Our case demonstrates that a combined LSCS and GIST resection is feasible. In addition, our case highlights the importance of both the multidisciplinary setting and the consideration of patients' wishes in the successful management of this complex group of patients.

Application of proteomics to soft tissue sarcomas

Soft tissue sarcomas are rare and account for less than 1% of all malignant cancers. Other than development of intensive therapies, the clinical outcome of patients with soft tissue sarcoma remains very poor, particularly when diagnosed at a late stage. Unique mutations have been associated with certain soft tissue sarcomas, but their etiologies remain unknown. The proteome is a functional translation of a genome, which directly regulates the malignant features of tumors. Thus, proteomics is a promising approach for investigating soft tissue sarcomas. Various proteomic approaches and clinical materials have been used to address clinical and biological issues, including biomarker development, molecular target identification, and study of disease mechanisms. Several cancer-associated proteins have been identified using conventional technologies such as 2D-PAGE, mass spectrometry, and array technology. The functional backgrounds of proteins identified were assessed extensively using in vitro experiments, thus supporting expression analysis. These observations demonstrate the applicability of proteomics to soft tissue sarcoma studies. However, the sample size in each study was insufficient to allow conclusive results. Given the low frequency of soft tissue sarcomas, multi-institutional collaborations are required to validate the results of proteomic approaches.

Management of small cell lung cancer: recent developments for optimal care

Small cell lung cancer (SCLC) represents approximately 13% of all lung cancer diagnoses and the incidence has reduced over the last 20 years. Treatment of SCLC remains challenging because of its rapid growth, early dissemination and development of drug resistance during the course of the disease. Chemotherapy remains the cornerstone of treatment for limited (LD) and extensive disease (ED), with concurrent chemotherapy and radical thoracic radiotherapy representing the best treatment option for fit patients with LD. Platinum-based chemotherapy is the treatment of choice in fit patients with good organ function, and the radiosensitizing effect of cisplatin is critically important for concurrent chemoradiotherapy in LD. Anthracycline-containing regimens represent a viable alternative for patients where platinum-based chemotherapy is contraindicated. Patients who relapse or progress after first-line chemotherapy have a very poor prognosis. Second-line therapy may produce a modest clinical benefit. Maintenance chemotherapy has not been shown to convincingly improve outcomes for SCLC. A number of targeted agents have been investigated in LD and ED, mostly in unselected populations, with disappointing results. Prophylactic cranial irradiation has been shown to reduce the incidence of brain metastases and prolong survival for both LD and ED without negative impact on quality of life (QOL) and cognitive function. Ongoing trials will shed some light on the impact of thoracic radiotherapy on QOL, symptom control and survival in ED SCLC patients who benefitted from first-line chemotherapy.

Consensus report on the radiological management of patients with gastrointestinal stromal tumours (GIST): recommendations of the German GIST Imaging Working Group

The aim was to reach consensus in imaging for staging and follow-up as well as for therapy response assessment in patients with gastrointestinal stromal tumours (GIST). The German GIST Imaging Working Group was formed by 9 radiologists engaged in assessing patients with GIST treated with targeted therapy. The following topics were discussed: indication and optimal acquisition techniques of computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET)/CT; tumour response assessment considering response criteria and measurement techniques on CT, MRI and PET/CT; result interpretation; staging interval and pitfalls. Contrast-enhanced CT is the standard method for GIST imaging. MRI is the method of choice in case of liver-specific questions or contraindications to CT. PET/CT should be used for early response assessment or inconclusive results on morphologic imaging. All imaging techniques should be standardized allowing a reliable response assessment. Response has to be assessed with respect to lesion size, lesion density and appearance of new lesions. A critical issue is pseudoprogression due to myxoid degeneration or intratumoural haemorrhage. The management of patients with GIST receiving a targeted therapy requires a standardized algorithm for imaging and an appropriate response assessment with respect to changes in lesion size and density.

Imatinib rechallenge in patients with advanced gastrointestinal stromal tumors

BACKGROUND

Imatinib is the standard of care for patients with advanced gastrointestinal stromal tumors (GIST).

DESIGN

This article reviews recent data on the impact of imatinib treatment interruption and subsequent rechallenge in patients with advanced GIST.

RESULTS

The randomized BFR14 trial showed that (i) interruption of imatinib after 1, 3, or 5 years of treatment in patients with nonprogressive GIST was associated with a high risk of progression even in patients with a complete response; (ii) rechallenge with imatinib restored tumor control in most patients, but the tumor response seldom reached that before treatment interruption; (iii) patients receiving continuous imatinib had a high rate of prolonged tumor control, which increased with longer imatinib treatment. The findings in the metastatic setting have important implications regarding the duration of adjuvant imatinib in GIST.

CONCLUSIONS

Discontinuation of imatinib in responding patients with advanced GIST is associated with a high risk of progression and is therefore not recommended. Although rechallenge is a strategy for treating patients who relapse after stopping imatinib, suboptimal tumor response indicates that continuous kinase suppression is necessary to achieve the best clinical outcome. Three-year adjuvant imatinib is recommended for patients with resected 'high-risk' GIST; however, a longer duration may provide additional benefits.

Prognostic impacts of hypoxic markers in soft tissue sarcoma

Background. We aimed to explore the prognostic impact of the hypoxia-induced factors (HIFαs) 1 and 2, the metabolic HIF-regulated glucose transporter GLUT-1, and carbonic anhydrase IX (CAIX) in non-gastrointestinal stromal tumor soft tissue sarcomas (non-GIST STS). Methods. Duplicate cores with viable tumor tissue from 206 patients with non-GIST STS were obtained and tissue microarrays were constructed. Immunohistochemistry (IHC) was used to evaluate expression of hypoxic markers. Results. In univariate analyses, GLUT-1 (P < 0.001) and HIF-2α (P = 0.032) expression correlated significantly with a poor disease-specific survival (DSS). In the multivariate analysis, however, only high expression of GLUT-1 (HR 1.7, CI 95% 1.1–2.7, P = 0.021) was a significant independent prognostic indicator of poor DSS. Conclusion. GLUT-1 is a significant independent negative prognostic factor in non-GIST STS.

Pediatric gastrointestinal stromal tumor

Pediatric gastrointestinal stromal tumor (GIST) is a rare entity that can be quite different from its adult counterpart. This report provides a comprehensive review on the diagnosis and management of this tumor in children and adolescents, including its oncogenesis and associated syndromes. Surgery remains a mainstay of treatment, but there are no standard guidelines available at this time regarding the best practice for multimodality therapy as our understanding of the biology of GIST is still in evolution. Therefore, pediatric patients with GIST should be ideally treated in the context of clinical trials at specialized, multidisciplinary centers throughout the course of their disease, especially because these patients may live for years after diagnosis.

Acute gastrointestinal bleeding from a submucosal gastric mass

We report a case of a 44-year-old male patient who presented with melena and hemodynamic instability. The endoscopic investigation of the upper and lower gastrointestinal tract was initially negative, but a repeat gastroduodenoscopy revealed a submucosal mass in the lesser curvature of the stomach with central erosion, primarily perceived as ectopic pancreas, but it was later discovered that it pertained to a gastrointestinal stromal tumor.

Histopathology of gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST), generally driven by oncogenic KIT or PDGFRA mutations, is the most common mesenchymal tumor of the gastrointestinal (GI) tract. GIST is most common in the stomach (60%) and small intestine (30%), but can occur anywhere in the GI-tract and the intra-abdominal soft tissues. GIST can show spindle cell or epithelioid morphology, and mitotic count and tumor size are most important prognostic parameters. GISTs in NF1 patients and children are distinctive clinicopathologic groups. Immunohistochemical testing for KIT and sometimes for DOG1/Ano 1 is essential in confirming the diagnosis.

Gastrointestinal stromal tumor surgery and adjuvant therapy

Gastrointestinal stromal tumors (GIST) are a unique class of mesenchymal tumors identified within the past decade. Intense molecular and genetic study has been used to characterize these tumors and develop treatment strategies. Although the mainstay of treatment remains surgical resection, therapy targeted at inhibiting tyrosine kinases has had dramatic results. Because of the rapid accumulation of information about the diagnosis and treatment of these tumors, the National Comprehensive Cancer Network convened a GIST task force to provide updated recommendations in 2010. As understanding of these tumors advances, rapid changes in recommendations will continue and should warrant regular updates in tumor management.

Pfetin as a prognostic biomarker for gastrointestinal stromal tumor: validation study in multiple clinical facilities

OBJECTIVE

The aim of this study is to confirm the prognostic value of pfetin in gastrointestinal stromal tumor patients. We recently reported the utility of pfetin, a novel prognostic biomarker in gastrointestinal stromal tumor. Gastrointestinal stromal tumor spans a wide spectrum from cases with curable disease to those with fatal tumors due to metastasis and recurrence. There is no biomarker predicting metastasis and/or recurrence of gastrointestinal stromal tumor though imatinib mesylate can improve recurrence-free survival.

METHODS

Pfetin expression was examined in 40 gastrointestinal stromal tumor patients from the Juntendo University Shizuoka Hospital using immunohistochemistry. Correlations between immunohistochemical findings and clinicopathologic parameters were examined. The pfetin expression results were integrated with the clinicopathologic data in a total of 299 cases including our 40 new gastrointestinal stromal tumor cases and 259 others with previously reported data.

RESULTS

Immunohistochemical study demonstrated the disease-free survival rate to be 93.75% for pfetin-positive and 25.0% for pfetin-negative patients among the 40 cases from the Juntendo University Shizuoka Hospital (P= 0.0006). When all 299 cases were included, the disease-free survival rate was 92.44% for pfetin-positive and 60.81% for pfetin-negative patients (P< 0.0001). Both uni- and multivariate analyses revealed that, among the clinicopathologic parameters examined, only pfetin expression was an independent prognostic factor (P< 0.05).

CONCLUSIONS

These results confirm the possible clinical utility of pfetin as a prognostic biomarker for gastrointestinal stromal tumor. Pfetin appears to be a novel clinically applicable prognostic factor, which may be useful for deciding whether to administer imatinib mesylate or not.