Gastrointestinal stromal tumor: a clinical overview

Gastrointestinal Stromal Tumors Mimicking Ovarian Mass: A Case Report

Gastrointestinal stromal tumors (GIST) are common mesenchymal tumors of the gastrointestinal tract. Some somatic factors have been linked to an increased incidence risk. The diagnostic process for GIST poses difficulties since it bears limited resemblance to ovarian masses, given its manifestation through symptoms like abdominal pain, abdominal mass, fever, weight loss, and loss of appetite. Patients with GIST usually exhibit clinical symptoms and signs of an abdominal mass and chronic pelvic pain might look like an ovarian mass, and diagnosed as GIST on histological examination. A 50-year-old woman presented to the gynecology outpatient department with complaints of an abdominal lump accompanied by pain and decreased appetite persisting for five months, leading to a preliminary diagnosis of an ovarian mass. Further evaluation by histopathological examination was confirmed to be GIST on the final diagnosis.

Surgical Options for Peritoneal Surface Metastases from Digestive Malignancies-A Comprehensive Review

The peritoneum is a common site for the dissemination of digestive malignancies, particularly gastric, colorectal, appendix, or pancreatic cancer. Other tumors such as cholangiocarcinomas, digestive neuroendocrine tumors, or gastrointestinal stromal tumors (GIST) may also associate with peritoneal surface metastases (PSM). Peritoneal dissemination is proven to worsen the prognosis of these patients. Cytoreductive surgery (CRS), along with systemic chemotherapy, have been shown to constitute a survival benefit in selected patients with PSM. Furthermore, the association of CRS with hyperthermic intraperitoneal chemotherapy (HIPEC) seems to significantly improve the prognosis of patients with certain types of digestive malignancies associated with PSM. However, the benefit of CRS with HIPEC is still controversial, especially due to the significant morbidity associated with this procedure. According to the results of the PRODIGE 7 trial, CRS for PSM from colorectal cancer (CRC) achieved overall survival (OS) rates higher than 40 months, but the addition of oxaliplatin-based HIPEC failed to improve the long-term outcomes. Furthermore, the PROPHYLOCHIP and COLOPEC trials failed to demonstrate the effectiveness of oxaliplatin-based HIPEC for preventing peritoneal metastases development in high-risk patients operated for CRC. In this review, we discuss the limitations of these studies and the reasons why these results are not sufficient to refute this technique, until future well-designed trials evaluate the impact of different HIPEC regimens. In contrast, in pseudomyxoma peritonei, CRS plus HIPEC represents the gold standard therapy, which is able to achieve 10-year OS rates ranging between 70 and 80%. For patients with PSM from gastric carcinoma, CRS plus HIPEC achieved median OS rates higher than 40 months after complete cytoreduction in patients with a peritoneal cancer index (PCI) ≤6. However, the data have not yet been validated in randomized clinical trials. In this review, we discuss the controversies regarding the most efficient drugs that should be used for HIPEC and the duration of the procedure. We also discuss the current evidence and controversies related to the benefit of CRS (and HIPEC) in patients with PSM from other digestive malignancies. Although it is a palliative treatment, pressurized intraperitoneal aerosolized chemotherapy (PIPAC) significantly increases OS in patients with unresectable PSM from gastric cancer and represents a promising approach for patients with PSM from other digestive cancers.

GIST: Correlation of risk classifications and outcome

In clinical practice, there are often discrepancies between the oncological prognosis of gastrointestinal stromal tumors (GIST) and the actual clinical course. This study aimed to check with our collective how reliably the current classifications (Miettinen, Fletcher) predict the prognosis of GIST and to evaluate whether an extension of the classifications by the parameter proliferation activity could make sense. This prospective study enrolled 58 patients who underwent surgery on GIST from 01/2006 to 12/2016. The postoperative course (curation, recurrence, progress) was correlated with the identified risk classification and the proliferative activity. Coincidences with other tumors were strikingly common in patients with GIST (43%). Based on the risk group assignment of GIST, no assessment of the probability of the occurrence of second neoplasia could be derived. Individual patients were under- or over-graduated concerning the assessment of biological behavior based on the standard risk classifications. The inclusion of proliferative activity did not allow for a more precise predictive power - neither to the risk of recurrence and metastasis nor to the development of a second neoplasia. The study showed that there is currently no parameter or logarithm that reliably predicts the biological behavior of GIST. Due to the frequency of coincidence of second neoplasia and (rare) distant metastases, for everyday clinical practice, appropriate staging diagnostic and regular follow-up care should also be used for benign GIST.

Isatin Hybrids and Their Pharmacological Investigations

Hybridization is an important strategy to design molecules that can be effectively used to treat fatal diseases known to mankind. Molecular hybrids and their pharmacological investigations aided in discovering several potent isatin (Indole 2, 3 dione) derivatives with anti-HIV, antimalarial, antitubercular, antibacterial, and anticancer activities. Indole-2,3-dione and their derivatives have diverse pharmacological properties and have a prominent role in the discovery of new drugs. To understand the various approaches for designing new molecules based on isatin nucleus analysis of various pharmacophore hybrids, spacers/linkers between pharmacophores and isatin for hybridization and their biological activities are important. This review discusses the progress in developing isatin hybrids as biologically effective agents and their crucial aspects of design and structure-activity relationships.

Debulking surgery for malignant tumors: the current status, evidence and future perspectives

Debulking surgery, also called cytoreductive surgery, is a resection of the tumor as much as possible and an intended incomplete resection for unresectable malignant tumors. Since the most important principle in surgical oncology is complete R0 resection, debulking surgery goes against the basic principle and obscures the concept of operability. However, debulking surgery has been advocated for various types of advanced malignant tumors, including gynecological cancers, urological cancers, gastrointestinal cancers, breast cancers and other malignancies, with or without adjuvant therapy. Positive data from randomized trials have been shown in subsets of ovarian cancer, renal cell carcinoma, colorectal cancer and breast cancer. However, recent trials for renal cell carcinoma, colorectal cancer and breast cancer have tended to show controversial results, mainly according to the survival improvement of nonsurgical systemic therapy alone. On the other hand, debulking surgery still has a therapeutic role for slow-growing and borderline malignant tumors, such as pseudomyxoma peritonei and thymomas. The recent understanding of tumor heterogeneity and clonal evolution responsible for malignancy and drug resistance indicates that select patients may obtain prolonged survival by the synergistic effect of debulking surgery and novel systemic therapy. This review aimed to describe the current status and evidence of debulking surgery in a cross-organ manner and to discuss future perspectives in the current era with advances in systemic therapy.

Anaplastic Thyroid Carcinoma: Current Issues in Genomics and Therapeutics

PURPOSE OF REVIEW

Anaplastic thyroid carcinoma is a type of thyroid carcinoma with the most aggressive biological behaviour amongst thyroid cancer. Here, we review the current genomic and the impacts of advances in therapies to improve the management of patients with the cancer.

RECENT FINDINGS

Common mutations being identified in anaplastic thyroid carcinoma are p53 and TERT promoter mutations. Other common mutated genes included BRAF, RAS, EIF1AX, PIK3CA, PTEN and AKT1, SWI/SNF, ALK and CDKN2A. Changes in expression of different microRNAs are also involved in the pathogenesis of anaplastic thyroid carcinoma. Curative resection combined with radiotherapy and combination chemotherapies (such as anthracyclines, platins and taxanes) has been shown to have effects in the treatment of some patients with anaplastic thyroid carcinoma. Newer molecular targeted therapies in clinical trials target mostly the cell membrane kinase and downstream proteins. These include targeting the EGFR, FGFR, VEGFR, c-kit, PDGFR and RET on the cell membrane as well as VEGF itself and the downstream targets such as BRAF, MEK and mTOR. Immunotherapy is also being tested in the cancer. Updated knowledge of genomic as well as clinical trials on novel therapies is needed to improve the management of the patients with this aggressive cancer.

Primary Tumor Resection Improves Survival in Patients With Metastatic Gastrointestinal Stromal Tumors: A Preliminary Population-Based Analysis

Background: Surgery has been the primary treatment in patients with localized gastrointestinal stromal tumors (GISTs) for many decades, whereas it remains controversial regarding the efficacy of primary tumor resection for metastatic GISTs treated with chemotherapy, and likewise it is unclear who would benefit from the surgical resection.

Methods: GISTs patients with distant metastases were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2016. Cox proportional hazards regression models were used to identify prognostic factors of overall survival (OS) and cancer-specific survival (CSS). Kaplan-Meier analyses and log-rank tests were conducted to assess the effectiveness of surgery on survival.

Results: In total, of 455 patients with metastatic GISTs, 235 patients (51.6%) underwent primary tumor resection and 220 patients (48.4%) did not. Median survival of patients in resection group was 72 (95% CI: 62.90–81.10) months vs. 40 (95% CI: 29.53–50.47) months for those in non-resection group (p < 0.001). Similarly, surgery in conjunction with chemotherapy led to a favorable impact on survival than chemotherapy alone (OS: 72 vs. 40 months, p < 0.001; CSS: 74 vs. 44 months, p < 0.001). Multivariable analysis showed that both OS (HR: 0.581, 95% CI: 0.386–0.874, p = 0.009) and CSS (HR: 0.663, 95% CI: 0.439–0.912, p = 0.042] were dramatically improved in patients with surgical removal of primary site, as well as primary tumor size between 5 and 10 cm, while increasing age was predictive of poorer survival. Stratified analysis revealed that patients with tumor locations in the stomach demonstrated a prolonged survival after surgery, with no significant differential surgical effect between the stomach and small intestine.

Conclusions: Our study preliminarily suggests that carefully selected patients with metastatic GISTs might prolong survival after treatment of surgery, especially those with a primary tumor between 5 and 10 cm and a tumor located in the stomach.

Kinase inhibitors with viral oncolysis: Unmasking pharmacoviral approaches for cancer therapy

There are more than 500 kinases in the human genome, many of which are oncogenic once constitutively activated. Fortunately, numerous hyperactive kinases are druggable, and several targeted small molecule kinase inhibitors have demonstrated impressive clinical benefits in cancer treatment. However, their often cytostatic rather than cytotoxic effect on cancer cells, and the development of resistance mechanisms, remain significant limitations to these targeted therapies. Oncolytic viruses are an emerging class of immunotherapeutic agents with a specific oncotropic nature and excellent safety profile, highlighting them as a promising alternative to conventional therapeutic modalities. Nonetheless, the clinical efficacy of oncolytic virotherapy is challenged by immunological and physical barriers that limit viral delivery, replication, and spread within tumours. Several of these barriers are often associated with oncogenic kinase activity and, in some cases, worsened by the action of oncolytic viruses on kinase signaling during infection. What if inhibiting these kinases could potentiate the cancer-lytic and anti-tumour immune stimulating properties of oncolytic virotherapies? This could represent a paradigm shift in the use of specific kinase inhibitors in the clinic and provide a novel therapeutic approach to the treatment of cancers. A phase III clinical trial combining the oncolytic Vaccinia virus Pexa-Vec with the kinase inhibitor Sorafenib was initiated. While this trial failed to show any benefits over Sorafenib monotherapy in patients with advanced liver cancer, several pre-clinical studies demonstrate that targeting kinases combined with oncolytic viruses have synergistic effects highlighting this strategy as a unique avenue to cancer therapy. Herein, we review the combinations of oncolytic viruses with kinase inhibitors reported in the literature and discuss the clinical opportunities that represent these pharmacoviral approaches.

The Roles of Common Variation and Somatic Mutation in Cancer Pharmacogenomics

Cancer pharmacogenomics is the science concerned with understanding genetic alterations and its effects on the pharmacokinetics and pharmacodynamics of anti-cancer drugs, with the aim to provide cancer patients with the precise medication that will achieve a good response and cause low/no incidence of adverse events. Advances in biotechnology and bioinformatics have enabled genomic research to evolve from the evaluation of alterations at the single-gene level to studies on the whole-genome scale using large-scale genotyping and next generation sequencing techniques. International collaborative efforts have resulted in the construction of databases to curate the identified genetic alterations that are clinically significant, and these are currently utilized in clinical sequencing and liquid biopsy screening/monitoring. Furthermore, countless clinical studies have accumulated sufficient evidence to match cancer patients to therapies by utilizing the information of clinical-relevant alterations. In this review we summarize the importance of germline alterations that act as predictive biomarkers for drug-induced toxicity and drug response as well as somatic mutations in cancer cells that function as drug targets. The integration of genomics into the medical field has transformed the era of cancer therapy from one-size-fits-all to cancer precision medicine.

EPIGIST: An observational real-life study on patients with metastatic gastrointestinal stromal tumors receiving imatinib

Background

Gastrointestinal stromal tumors (GISTs) are rare, but represent the most common mesenchymal neoplasms of the gastrointestinal tract. EPIdemiology GIST, is an observational multicenter longitudinal follow-up cohort study reporting the prescribing patterns of imatinib in patients with GIST and the impact of the treatment in a real-world (standard clinical) setting.

Methods

Eligible patients had a confirmed diagnosis of unresectable or metastatic KIT-positive GIST and started treatment with imatinib for the first time between May 24, 2002, and June 30, 2010. During routine visits, annual collection of clinical characteristics was requested, i.e., age, GIST stage at diagnosis, history, imatinib treatment duration and dosage, adherence, and concomitant medications. Survival outcomes were estimated using the Kaplan-Meier method. Other data were analyzed using descriptive statistics.

Results

Of 151 patients enrolled, imatinib was initiated for 126 patients before enrollment and for 25 patients on the day of enrollment or soon after. The patient characteristics were similar to those in published prospective trials. The estimated 1-, 2-, 3-, and 4-year overall survival rates were 90.4% (95% confidence interval [CI; 84.8%-94.0%]), 84.7% (95% CI [78.1%-89.4%]), 73.0% (95% CI [65.0%-79.4%]), and 60.7% (95% CI [51.4%-68.8%]), respectively. The most common adverse events (AEs) were diarrhea (39%), asthenia (39%), eyelid or periorbital edema (32%), abdominal pain (23%), and anemia (21%). Eight of 126 serious AEs were possibly related to the treatment as assessed by investigators.

Conclusions

Study results showed that patients in real-life populations are generally treated in accordance with national and international clinical recommendations and have outcomes comparable to those of patients in clinical trials.

Management of hemorrhage in gastrointestinal stromal tumors: a review

Gastrointestinal stromal tumors (GISTs) are relatively common mesenchymal tumors. They originate from the wall of hollow viscera and may be found in any part of the digestive tract. The prognosis of patients with stromal tumors depends on various risk factors, including size, location, presence of mitotic figures, and tumor rupture. Emergency surgery is often required for stromal tumors with hemorrhage. The current literature suggests that stromal tumor hemorrhage indicates poor prognosis. Although the optimal treatment options for hemorrhagic GISTs are based on surgical experience, there remains controversy with regard to optimum postoperative management as well as the classification of malignant potential. This article reviews the biological characteristics, diagnostic features, prognostic factors, treatment, and postoperative management of GISTs with hemorrhage.

Anaplastic thyroid carcinoma: from clinicopathology to genetics and advanced therapies

Anaplastic thyroid carcinoma (ATC) is a rare malignancy, accounting for 1-2% of all thyroid cancers. Although rare, ATC accounts for the majority of deaths from thyroid carcinoma. ATC often originates in a pre-existing thyroid cancer lesion, as suggested by the simultaneous presence of areas of differentiated or poorly differentiated thyroid carcinoma. ATC is characterized by the accumulation of several oncogenic alterations, and studies have shown that an increased number of oncogenic alterations equates to an increased level of dedifferentiation and aggressiveness. The clinical management of ATC requires a multidisciplinary approach; according to recent American Thyroid Association guidelines, surgery, radiotherapy and/or chemotherapy should be considered. In addition to conventional therapies, novel molecular targeted therapies are the most promising emerging treatment modalities. These drugs are often multiple receptor tyrosine kinase inhibitors, several of which have been tested in clinical trials with encouraging results so far. Accordingly, clinical trials are ongoing to evaluate the safety, efficacy and effectiveness of these new agents. This Review describes the updated clinical and pathological features of ATC and provides insight into the molecular biology of this disease. The most recent literature regarding conventional, newly available and future therapies for ATC is also discussed.

Percutaneous microwave ablation liver partition and portal vein embolization for planned hepatectomy due to large gastrointestinal stromal tumor metastases: A case report

RATIONALE

The liver is the most frequent site of relapse of gastrointestinal stromal tumors (GISTs). Surgery is always considered to be unsuitable because of the multiple metastases.

PATIENT CONCERNS

In this report, we describe a case of large, multiple GIST liver metastases that were treated with percutaneous microwave ablation liver partition and portal vein embolization for planned hepatectomy (PALPP). A 44-year-old woman had undergone pancreaticoduodenectomy 4 years previously because of the diagnosis of a large duodenal GIST. Large, multiple liver metastases were observed 2 years later.

DIAGNOSES

GIST liver metastasis was diagnosed using percutaneous ultrasound-guided biopsy.

INTERVENTIONS

After 6 months of treatment with imatinib, the liver metastasis was stable. PALPP was performed because of insufficient future liver remnant (FLR) and right trisegmentectomy was successfully completed 10 days later.

OUTCOMES

The patient has had no signs of local or systemic disease during 17 months of postsurgical follow-up.

LESSONS

PALPP provides a new methodology for treatment of GIST liver metastasis in patients with insufficient FLR, and may have benefit in prolonging a durable remission.

Management of Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal tract. The stomach is the most common site of origin. Management of GISTs changed after the introduction of molecularly targeted therapies. Although the only potentially curative treatment of resectable primary GISTs is surgery, recurrence is common. Patients with primary GISTs at intermediate or high risk of recurrence should receive imatinib postoperatively. Imatinib is also first-line therapy for advanced disease. Cytoreductive surgery might be considered in advanced GIST for patients with stable/responding disease or limited focal progression on tyrosine kinase inhibitor therapy. GIST requires multidisciplinary management.

Gastrointestinal stromal tumor with a PDGFRA mutation masquerading as gastric plexiform fibromyxoma: A comparative clinicopathological study of two cases

Gastric plexiform fibromyxoma (PF) is a rare mesenchymal tumor with a histologically distinctive multinodular pattern, dissimilar to conventional gastrointestinal stromal tumor (GIST). The current study presents one case of gastric PF, and one case of GIST with a platelet-derived growth factor receptor α (PDGFRA) mutation mimicking PF, and discusses their differential diagnoses. The two patients were a 51-year-old male with PF and a 47-year-old female with GIST, each of whom presented with an occupying lesion in the gastric antrum. Histologically, the two cases shared a rare and approximately unanimous morphological pattern of a prominent multinodular and plexiform figuration in the gastric wall, including mucoid matrix, short spindle cells and small caliber vascular elements, and areas of stromal tumor cells exhibited an epithelioid appearance. Immunohistochemistry revealed that the PF tumor cells were positive for smooth muscle actin (SMA), but negative for mast/stem cell growth factor receptor (KIT), GIST-1 (DOG1), cluster of differentiation (CD) 34, S-100, desmin and cytokeratin AE1/AE3. The case of GIST expressed KIT and DOG1, but was negative for SMA, CD34, S-100, desmin and AE1/AE3. In addition, the GIST case, which was observed to harbor a D842V mutation in exon 18 of PDGFRA, was demonstrated to be genetically distinct from PF. The cases presented in the current study were uncommon in that GIST exhibited a plexiform appearance that mimicked the histology of the rare PF tumor; therefore, GIST must be considered and discounted first when determining a differential diagnosis for a gastrointestinal mesenchymal neoplasm.

Small intestinal stromal tumors: Clinical features and factors related to misdiagnosis

AIM

To analyze the clinical characteristics of small intestinal stromal tumors (SISTs) and identify factors related to their misdiagnosis.

METHODS

Clinical data of 104 patients with pathologically proved SISTs were retrospectively analyzed at our hospital from January 2010 to January 2015, with regard to clinical features, tumor location, tumor size, diagnostic methods, and risk classification.

RESULTS

Common clinical symptoms included abdominal mass (67/104, 64.5%), gastrointestinal bleeding (47/104, 52.8%), and abdominal pain (47/104, 52.8%). The lesions were seen mainly in the jejunum (45.2%), followed by the ileum (29.8%) and duodenum (25%). The misdiagnosis rate was as high as 34.6%, and SISTs were often misdiagnosed as gynecological tumors (15/36), digestive tract leiomyomas (6/36) and other diseases. The misdiagnosis was related, to a certain extent, to clinical manifestations, tumor location, tumor size, growth mode, examination methods and other factors, but had nothing to do with sex, age of onset, risk classification, or metastasis.

CONCLUSION

SISTs frequently occur in the jejunum, with gastrointestinal bleeding and abdominal mass being common clinical manifestations. Its clinical misdiagnosis rate is high. Therefore, for patients with recurrent gastrointestinal bleeding and abdominal mass that cannot be clearly diagnosed by color Doppler ultrasound, CT and digestive endoscopy, timely surgical biopsy and immunohistochemistry examination should be performed to achieve early diagnosis and avoid misdiagnosis.

The Role of Surgery in Metastatic Gastrointestinal Stromal Tumors

OPINION STATEMENT

Gastrointestinal stromal tumors (GISTs) are the most common sarcomas and mesenchymal neoplasms of the gastrointestinal tract. Macroscopically complete (R0/R1) resection is the standard treatment for localized resectable GIST with adjuvant imatinib therapy recommended for patients with intermediate or high-risk disease. In patients with advanced unresectable or metastatic GIST, imatinib has significantly improved outcomes. However, while most patients achieve partial response (PR) or stable disease (SD) on imatinib (with maximal response typically seen by 6 months on treatment), approximately half will develop secondary resistance by 2 years. Available data suggest that cytoreductive surgery may be considered in patients with metastatic GIST who respond to imatinib, particularly if a R0/R1 resection is achieved. The benefit of surgery in patients with focal tumor progression on imatinib is unclear, but may be considered. Patients with multifocal progression undergoing surgery generally have poor outcomes. Thus, surgery should be considered in patients with metastatic GIST whose disease responds to imatinib with a goal of performing R0/R1 resection. Optimal timing of surgery is unclear but should be considered between 6 months and 2 years after starting imatinib. Although surgery in patients with metastatic GIST treated with sunitinib is feasible, incomplete resections are common, complication rates are high, and survival benefit is unclear. Therefore, a careful multidisciplinary consultation is required to determine optimal treatment options on a case-by-case basis. Finally, patients with metastatic GIST should resume tyrosine kinase inhibitor treatment postoperatively.

Cancer heterogeneity determined by functional proteomics

Current manuscript gives a synopsis of tumor heterogeneity related to patient samples analyzed by proteomics, protein expression analysis and imaging mass spectrometry. First, we discuss the pathophysiologocal background of cancer biology as a multifactorial and challenging diseases. Disease pathology forms the basis for protein target selection. Therefore, histopathological diagnostics and grading of tumors is highlighted. Pathology is the cornerstone of state-of-the-art diagnostics of tumors today both by establishing dignity and - when needed - describing molecular properties of the cancers. Drug development by the pharmaceutical industry utilizes proteomics studies to pinpoint the most relevant targets. Molecular studies profiling affinity-interactions of the protein(s) with targeted small drug molecules to reach efficacy and optimal patient safety are today requested by the FDA and other agencies for new drug development. An understading of basic mechanisms, controlling drug action and drug binding is central, as a new era of personalized medicine becomes an important milestone solution for the healthcare sector as well as the Pharma and Biotech industry. Development of further diagnostic, prognostic and predictive tests will aid current and future treatment of cancer patients. In the paper we present current status of Proteomics that we believe requires attention in order to collectively advance forward in the fight against cancer, addressing the burning opportunities and challenges.

Gastrointestinal Stromal Tumor Mimicking as Ovarian Tumor in Gynaecologic Oncology

To report the clinical presentation and outcomes of a series of patients who presented with abdominal/pelvic mass or pelvic pain and were diagnosed with a gastrointestinal stromal tumor (GIST). Retrospective data were collected of all patients who presented with an abdominal/pelvic mass or pelvic pain between January 2010 and July 2015 and who were ultimately diagnosed with a GIST. The patients' medical records were reviewed. A literature review was also conducted. The event free survival and overall survival was calculated for all patients using Kaplan Meier curve (SPSS19-SPSS Inc. USA). A total ten patients were identified with GIST during the study period. Eight of ten patients had a tumor in the small intestine, one in sigmoid colon and one in base of small bowel mesentry. The mean tumor size was 13.9 cm (range, 3.9 to 24 cm). A complete resection was achieved in all 10 patients. No patient had distance metastasis. There were no intraoperative complications. One patient developed postoperative intestinal fistula and was managed conservatively. All patients were treated with imatinib after surgery. The mean follow-up time was 18 months (range, 2 to 47 months). The seven of the 10 patients (70 %) with no evidence of disease, two (20 %) lost follow up and one patient developed recurrence during follow up period and was started on sunitinib and patient died during follow up period because of disease. Gastrointestinal stromal tumors should be considered in the differential diagnosis of patients presenting with an abdominal/pelvic mass or pelvic pain in Gynaecologic oncology department. In such unusual circumstances the complete resection and appropriate adjuvant treatment results in complete durable remission.

A Pancreatic Head Tumor Arising as a Duodenal GIST: A Case Report and Review of the Literature

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors of the gastrointestinal tract that originate from the intestinal cells of Cajal (ICC) (Fletcher et al., 2002). Only a few cases have been described with extragastrointestinal stromal tumors (Kim et al., 2012; Soufi et al., 2013; Meng et al., 2011). They are often diagnosed as a pancreatic head tumor as they are very difficult to relate to the duodenum with CT, MRI, or ultrasound. We present a case of a sixty-four-year-old woman who presented with abdominal pain and cardialgia for a follow-up examination after breast cancer surgery. On laparotomy there was a 3 × 5 cm hypervascular mass arising from the pancreatic head with macroscopically no attachment to the duodenum. The patient underwent pancreatoduodenectomy (PD) modified after Traverso-Longmire, histopathology proved a duodenal GIST. This case proves that duodenal GISTs can grow invasively into the pancreas and appear as solid pancreas head tumor; therefore, these tumors should be included into differential diagnosis.

Prevalence of gastrointestinal stromal tumour (GIST) in the United Kingdom at different therapeutic lines: an epidemiologic model

BACKGROUND

The prevalence of patients with gastrointestinal stromal tumourgst (GIST) who fail currently available treatments imatinib and sunitinib (third-line treatment-eligible GIST) is unknown, but is expected to be below an ultra-orphan disease threshold of 2/100,000 population used in England and Wales. Our study was designed to estimate the prevalence and absolute number of UK patients with unresectable/metastatic GIST at first-, second- and eventually third-line treatment.

METHODS

Our open population model estimates the probability that the prevalence of UK third-line treatment-eligible GIST patients will remain under the ultra-orphan disease threshold. Model parameters for incidence, proportion of unresectable/metastatic disease and survival estimates for GIST patients were obtained from a targeted literature review and a UK cancer register. The robustness of the results was checked through differing scenarios taking extreme values of the input parameters.

RESULTS

The base-case scenario estimated a prevalence of third-line treatment-eligible GIST of 1/100,000 and a prevalence count of 598 with a 99.9% likelihood of being below the ultra-orphan disease threshold. The extreme scenarios, one-way and probabilistic sensitivity analyses and threshold analysis confirmed the robustness of these results.

CONCLUSIONS

The prevalence of third-line treatment-eligible GIST is very low and highly likely below the ultra-orphan disease threshold.

Gastrointestinal stromal tumor

Gastrointestinal stromal tumor has received a lot of attention over the last 10 years due to its unique biologic behavior, clinicopathological features, molecular mechanisms, and treatment implications. GIST is the most common mesenchymal neoplasm in the gastrointestinal tract and has emerged from a poorly understood and treatment resistant neoplasm to a well-defined tumor entity since the discovery of particular molecular abnormalities, KIT and PDGFRA gene mutations. The understanding of GIST biology at the molecular level promised the development of novel treatment modalities. Diagnosis of GIST depends on the integrity of histology, immunohistochemistry and molecular analysis. The risk assessment of the tumor behavior relies heavily on pathological evaluation and significantly impacts clinical management. In this review, historic review, epidemiology, pathogenesis and genetics, diagnosis, role of molecular analysis, prognostic factor and treatment strategies have been discussed.

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

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that are best classified as sarcomas with variable aggressiveness. They are typically treated with surgical resection and adjuvant tyrosine kinase inhibitors or, for advanced/metastatic GISTs, with tyrosine kinase inhibitors alone. Gastroenterologists are often the first to detect GISTs and are, therefore, tasked with diagnosis and facilitation of early intervention. Diagnostic tools including various imaging techniques such as endoscopic ultrasound (EUS) and EUS-assisted tissue sampling are critical for an accurate diagnosis. In the case of small tumors, EUS-assisted resection or ligation techniques to treat asymptomatic small tumors have been described. This paper reviews current evidence for the diagnosis and management of GISTs, with an emphasis on the role of the gastroenterologist.

Radiological features of metastatic gastrointestinal stromal tumors

The imaging features of 42 histopathologically confirmed cases of Gastrointestinal Stromal Tumors (GIST) were analyzed, to observe the pattern of metastasis. At presentation 22 of 42 patients (52.3%) showed metastasis. During follow-up, three more cases developed metastasis, within one year of resection. Mesentery, omentum, and liver were the most frequent sites for metastasis. Other sites that were rarely reported to be involved were increasingly recognized to show metastasis due to longer survival. The metastasis often showed attenuation and enhancement characteristics, similar to primary GIST, and frequently showed necrosis, hemorrhage, and calcification.

Array-based pharmacogenomics of molecular-targeted therapies in oncology

The advent of microarrays over the past decade has transformed the way genome-wide studies are designed and conducted, leading to an unprecedented speed of acquisition and amount of new knowledge. Microarray data have led to the identification of molecular subclasses of solid tumors characterized by distinct oncogenic pathways, as well as the development of multigene prognostic or predictive models equivalent or superior to those of established clinical parameters. In the field of molecular-targeted therapy for cancer, in particular, the application of array-based methodologies has enabled the identification of molecular targets with 'key' roles in neoplastic transformation or tumor progression and the subsequent development of targeted agents, which are most likely to be active in the specific molecular setting. Herein, we present a summary of the main applications of whole-genome expression microarrays in the field of molecular-targeted therapies for solid tumors and we discuss their potential in the clinical setting. An emphasis is given on deciphering the molecular mechanisms of drug action, identifying novel therapeutic targets and suitable agents to target them with, and discovering molecular markers/signatures that predict response to therapy or optimal drug dose for each patient.

Gastrointestinal stromal tumors as an incidental finding in patients with a presumptive diagnosis of ovarian cancer

Objective

To report the clinical presentation and oncologic outcomes of a series of patients who presented with an abdominal or pelvic mass and were diagnosed with a gastrointestinal stromal tumor (GIST).

Methods

Data were obtained on all patients who presented with an abdominal or pelvic mass between September 2007 and June 2010 and who were ultimately diagnosed with a GIST. The patients' medical records were reviewed. A literature review was also conducted.

Results

Six patients were identified who met the inclusion criteria. All six patients had a tumor in the intestinal tract arising from the small bowel. The mean tumor size was 12 cm (range, 6 to 22 cm). A complete resection was achieved in five of the six patients. There were no intraoperative complications; one patient had a postoperative complication. Two patients were treated with imatinib after surgery. The mean follow-up time was 32 months (range, 0.3 to 40 months). At the last follow-up, five of the six patients were without any evidence of disease. One patient died of an unrelated hepatic encephalopathy. The incidence in our institution is 3%.

Conclusion

GISTs are uncommon; however, they should be considered in the differential diagnosis of patients presenting with an abdominal or pelvic mass.

Microvessel Density (Chalkley Method) in a Series of 79 Gastrointestinal Stromal Tumors

BACKGROUND

Evaluation of the MVD (modified Chalkley method) in a series of 79 cases of GISTs diagnosed by the Pathology Service at the HCPA (Hospital de Clinicas de Porto Alegre) from January 1993 to December 2009.

METHODS

Seventy nine cases of GISTs were submitted to immunohistochemical analysis for CD31, an endothelial marker, to analyze MVD. Hot spots were identified for each case, and the mean numbers of stained blood vessels collected through Chalkley count, with the use of a 25 point grid, placed onto a scanned image. Images were analysed through an image analysis system. We used a cutoff of six vessels.

RESULTS

Our series was composed of 42 males and 37 females and presented an average age of 58.9 years. GISTs were predominately located in the stomach (45.6%) followed by the small intestine (38.0%). Sixty seven GISTs (84.8%) showed an average of less than six vessels stained by CD31 (MVD) and 12 (15.2%) GISTs an average of more than six vessels. A statistically significant difference was observed between survival rate of patients having GISTs with MVD of ≤ 6 vessels (mean = 2.4, CI 95%: 1.67 - 3.17) and patients having GISTs with MVD of ≥ 6 vessels (mean = 2.4, CI 95%: 1.67 - 3.17), P = 0.001. No association for MVD was observed related to sex, age, histological type, risk category, location and metastasis.

CONCLUSIONS

Seventy nine cases of GISTs diagnosed at a single center in South Brazil were studied for MVD (Chalkley method). There was a statistically significant difference between MVD and the survival rate for these patients. The use of Chalkley method in GISTs may be helpful to evaluate clinical outcome.

MicroRNA-494 downregulates KIT and inhibits gastrointestinal stromal tumor cell proliferation

PURPOSE

Gain-of-function mutations and KIT overexpression are well-known tumorigenesis mechanisms in gastrointestinal stromal tumors (GIST). This study aimed to discover microRNAs (miRNA) that target KIT and reveal the relationship between the discovered miRNAs and KIT expression in GISTs.

EXPERIMENTAL DESIGN

Fresh-frozen GISTs from 31 patients were used to confirm the relationship between miR-494 and KIT expression using quantitative reverse transcription-PCR to assess miR-494 expression levels and Western blotting to assess KIT protein expression levels. A luciferase assay was conducted for the target evaluation. The functional effects of miR-494 on GIST882 cells (GIST cell line with activating KIT mutation) were validated by a cell proliferation assay and fluoresce-activated cell sorting analysis.

RESULTS

An inverse relationship was found between the expression levels of miR-494 and KIT in GISTs (r = -0.490, P = 0.005). The direct targeting of KIT by miR-494 was shown by the reduction in KIT expression after miR-494 overexpression and the increase in KIT expression after inhibiting endogenous miR-494 expression. We showed that miR-494 regulates KIT by binding two different seed match sites. Induced miR-494 overexpression in GIST882 reduced the expression of downstream molecules in KIT signaling transduction pathways, including phospho-AKT and phospho-STAT3. Finally, miR-494 overexpression provoked apoptosis and inhibited GIST cell growth, which were accompanied by changes in G(1) and S phase content.

CONCLUSION

Our findings indicate that miR-494 is a negative regulator of KIT in GISTs and overexpressing miR-494 in GISTs may be a promising approach to GIST treatment.

Exon 11 mutations, Ki67, and p16(INK4A) as predictors of prognosis in patients with GIST

Prognostic biomarkers for GIST are under investigation. The aim of this study was to assess whether exon 11 mutations, Ki67, and p16(INK4A) are predictors of prognosis in GIST. Consecutive GIST cases (n=84) had their specimens evaluated for exon 11 mutations and expression of Ki67 and p16(INK4A). Surgical cases were categorized according to NIH and Miettinen's classification, and survival was analyzed from hospital database. GISTs were predominately gastric (45%) and with spindle cell morphology (74%). The risk category was very low or low in 28%, intermediate in 23%, and high in 49%. Exon 11 mutation was identified in 29 (48%) out of 60 cases studied. There were 12 point mutations, 10 deletions, 4 duplications, and 3 double mutations. A third of GISTs had either high Ki67 index (>3%) or negativity for p16(INK4A). In multivariate analysis, independent predictors of mortality were Ki67>3% (HR=7.3; P=0.036) and high mitotic index (HR=10.4; P=0.043). There was no association between exon 11 mutations and survival. This study suggests that Ki67>3% is an independent predictor of poor prognosis in patients with GIST. Exon 11 mutations and negativity for p16(INK4A) need further studies to address the prognostic value.

Platelet-derived growth factor and transforming growth factor beta synergistically potentiate inflammatory mediator synthesis by fibroblast-like synoviocytes

Introduction

The objective of this study was to model the effects of transforming growth factor beta (TGF-β) and platelet-derived growth factor (PDGF), both present in rheumatoid arthritis (RA) synovia, on the behavior of fibroblast-like synoviocytes (FLS) in response to pro-inflammatory cytokine (interleukin (IL)1β, tumor necrosis factor-alpha (TNFα)) challenge.

Methods

Gene and protein expression by fibroblast-like synoviocytes in vitro was studied by quantitative Polymerase Chain Reaction (qPCR), ELISA and multiplex bead cytokine assays. Intracellular signaling pathway activation was determined by Western blot for phospho-kinases and the use of specific inhibitors.

Results

In combination, TGF-β and PDGF (2GF) synergistically augmented TNFα- or IL1β-induced matrix metalloproteinase 3 (MMP3), IL6, IL8, and macrophage inflammatory protein 1 alpha (MIP1α) secretion by FLS. Other FLS-derived mediators remained unaffected. Individually, neither growth factor significantly potentiated TNFα or IL1β-induced MMP3 secretion, and only slightly enhanced IL6. The effect of 2GF on TNFα-induced gene expression was transcriptionally mediated; blocked by imatinib mesylate; and occurred even if 2GF was added as much as four hours prior to TNFα. In addition, a 15-minute pulse of 2GF four hours prior to TNFα stimulation yielded a synergistic response. The extracellular-signal-regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K) signaling pathways were induced for at least four hours by 2GF, as demonstrated by persistently upregulated levels of phospho-Akt and phospho-ERK. However, pharmacologic inhibitor studies demonstrated that the potentiating action of 2GF was dependent on PI3 kinase only, and not on ERK.

Conclusions

The combination of PDGF and TGF-β dramatically potentiates FLS response to cytokines in a receptor-mediated and PI3 kinase-dependent fashion. These data suggest that 2GF contribute to synovitis by directing synovial fibroblasts toward a more aggressive phenotype in response to TNFα. Therefore, inhibition of growth factor signaling may constitute a complementary therapeutic approach to cytokine-targeted treatments for RA.

Role for the proapoptotic factor BIM in mediating imatinib-induced apoptosis in a c-KIT-dependent gastrointestinal stromal tumor cell line

The c-KIT receptor tyrosine kinase is constitutively activated and oncogenic in the majority of gastrointestinal stromal tumors. The identification of selective inhibitors of c-KIT, such as imatinib, has provided a novel therapeutic approach in the treatment of this chemotherapy refractory tumor. However, despite the clinical importance of these findings and the potential it provides as a model system for understanding targeted therapy, this approach has not yielded curative outcomes in most patients, and the biochemical pathways connecting c-KIT inhibition to cell death are not completely understood. Here, we show that inhibition of c-KIT with imatinib in gastrointestinal stromal tumors (GISTs) triggered the up-regulation of the proapoptotic protein BIM via both transcriptional and post-translational mechanisms. The inhibition of c-KIT by imatinib increased levels of the dephosphorylated and deubiquitinated form of BIM as well as triggered the accumulation of the transcription factor FOXO3a on the BIM promoter to activate transcription of BIM mRNA. Furthermore, using RNA interference directed against BIM, we demonstrated that BIM knockdown attenuated the effects of imatinib, suggesting that BIM functionally contributes to imatinib-induced apoptosis in GIST. The identification and characterization of the pathways that mediate imatinib-induced cell death in GIST provide for a better understanding of targeted therapy and may facilitate the development of new therapeutic approaches to further exploit these pathways.