Pancreatic Extragastrointestinal Stromal Tumor: A Case Report.

Gastrointestinal stromal tumors (GISTs) are soft tissue sarcomas that originate from the mesenchymal cells of the gastrointestinal tract. Extra-GISTs (EGISTs) are caused by sites outside the gastrointestinal tract. We reported a case of EGIST of the pancreas in a 51-year-old woman. Enhanced CT scan showed a rounded, slightly hypointense focus in the head of the pancreas and the right pars compacta of the descending duodenum. Routine laboratory and endocrine tests were unremarkable. The patient underwent laparoscopic surgery. The diagnosis of EGIST was confirmed through histopathological and immunohistochemical examination. The tumor was found to be CD117+, CD34+, and DOG+ with a high risk of malignancy. No recurrence was observed during the nine-month postoperative follow-up.

Combination of Type I and II tyrosine kinase inhibitors-avapritinib and sunitinib-in refractory gastrointestinal stromal tumor after failure to multi-line therapy: a case report.

Background: Tyrosine kinase inhibitors (TKIs) are currently the main treatment choice for gastrointestinal stromal tumors (GISTs). However, the long-term use of TKIs can lead to drug resistance. There is no study or clinical report of combination therapies of TKIs that have been approved for marketing. Combination pharmacotherapy is a new approach for patients who do not respond to monotherapy. This case provides a reference value for selective combination of TKIs in treating advanced GIST. Case Description: In this article, we report the case of a 55-year-old female who was diagnosed with duodenal GIST in April 2018 and underwent R0 resection. KIT exon 9 mutation was detected. The patient had disease recurrence with multiple abdominal metastases during imatinib adjuvant therapy after 27 months, and failure to 2nd-line sunitinib treatment after 6 months. She underwent a cytoreductive surgery (R1), and the postoperative mutation analysis suggested KIT exon 9 mutation, with newly found secondary KIT_exon16_p. L783V mutation and other mutations on TP53, POT1, and SETD2, etc. The patient experienced short-term tumor control of standard 3rd-line therapy of regorafenib and the rapid progression of the 4th-line of ripretinib afterwards. Different TKI combination therapies (i.e., ripretinib plus sunitinib, ripretinib plus avapritinib and avapritinib plus sunitinib) were administered to the patient sequentially. Ripretinib plus sunitinib led to stable disease but was discontinued due to intolerable adverse effects. Finally, the patient received a combination regimen of avapritinib plus sunitinib. The patient's tumor showed continuous shrinking in 2 consecutive computed tomography scan evaluations within 4 months with acceptable side effects. Conclusions: Combined type I and type II TKIs of avapritinib combined with sunitinib therapy achieved tumor regression for a heavily multi-line treated patient. Our case provides a reference for a savage treatment choice in refractory GISTs after failure to all standard treatment.

Ten-Year Survivorship in Patients with Metastatic Gastrointestinal Stromal Tumors.

INTRODUCTION: Patients developing metastatic gastrointestinal stromal tumors (mGIST) have heterogenous disease biology and oncologic outcomes; prognostic factors are incompletely characterized. We sought to evaluate predictors of 10-year metastatic survivorship in the era of tyrosine kinase inhibitor (TKI) therapy. METHODS: We reviewed patients with mGIST treated at our Comprehensive Cancer Center from 2003 to 2019, including only patients with either mortality or 10 years of follow-up. Ten-year survivorship was evaluated with logistic regression. RESULTS: We identified 109 patients with a median age of 57 years at mGIST diagnosis. Synchronous disease was present in 57% (n = 62) of patients; liver (n = 48, 44%), peritoneum (n = 40, 37%), and liver + peritoneum (n = 18, 17%) were the most common sites. Forty-six (42%) patients were 10-year mGIST survivors. Following mGIST diagnosis, radiographic progression occurred within 2 years in 53% (n = 58) of patients, 2-5 years in 16% (n = 17), and 5-10 years in 16% (n = 17), with median survival of 32, 76, and 173 months, respectively. Seventeen (16%) patients had not progressed by 10 years. Fifty-two (47%) patients underwent metastasectomy, which was associated with improved progression-free survival (hazard ratio 0.63, p = 0.04). In patients experiencing progression, factors independently associated with 10-year survivorship were age (odds ratio [OR] 0.96, p = 0.03) and time to progression (OR 1.71/year, p < 0.001). CONCLUSIONS: Ten-year survivorship is achievable in mGIST in the era of TKIs and is associated with younger age and longer time to first progression, while metastasectomy is associated with longer time to first progression. The role of metastasectomy in the management of patients with disease progression receiving TKI therapy merits further study.

Aspartate and Acetate Fuel Gastrointestinal Stromal Tumors Beyond the Warburg Effect.

Metabolic reprogramming is closely linked to the tumorigenesis and drug resistance of gastrointestinal stromal tumors (GISTs). Mapping the metabolic orbit of GISTs is a prerequisite if intervention against the metabolic vulnerability of refractory GISTs is desirable. Methods: A total of 43 patients with treatment-naïve GISTs who had undergone surgical resections were enrolled, on whom a metabolomics profile detected from surgical specimens was constructed based on the 1H-nuclear magnetic resonance (NMR) platform. The mRNA and protein levels of GLUT1, HK2, ACSS2, and FASN were assayed. Dual-tracer 18F-FDG/11C-acetate PET imaging was introduced before surgery in 15 patients. Results: 1H-NMR-based metabolomics revealed that GISTs were characterized by upregulation of glutamate, ascorbate, aspartate and glycine and downregulation of choline, creatine, glucose and glycerol. Bioinformatics analysis showed that the TCA cycle and alanine, aspartate, and glutamate metabolism were the two leading pathways. High- and nonhigh-risk (including intermediate-, low-, and very low-risk) GISTs preferentially displayed upregulation of HK2 and ACSS2, respectively, echoed by in vivo imaging that high- and nonhigh-risk GISTs preferentially exhibited higher uptake of 18F-FDG and 11C-acetate, respectively, while 18F-FDG and 11C-acetate were complementary to each other. Nuclear ACSS2 was exclusively identified in high-risk GISTs. Conclusion: We describe a metabolic landscape of GISTs that read aspartate as a de facto "oncometabolite," which was replenished via the TCA cycle and alanine, aspartate, and glutamate metabolism. Glycolysis and ACSS2-mediated acetate metabolism competed and complemented fatty acid synthesis, although glycolysis remained an aggressive phenotype.

Metastatic Liver Tumors in Surgical Pathology: Impact of Contemporary Diagnostic and Therapeutic Paradigms in a Tertiary Care Center.

We analyzed metastatic liver tumors received in the department of pathology in a tertiary care center over a 3-year period. There were 509 metastatic liver tumors; counterintuitively, there were as many resections (235 cases) as biopsies (274 cases). This unexpected finding reflects contemporaneous organ-specific paradigms for diagnosis and management of metastatic liver disease in oncologic practice, and the association of our practice with a National Cancer Institute-designated comprehensive cancer center with expertise and specialization in liver surgery. We receive a large number of resections for metastatic liver tumors because metastasectomy from a variety of primary tumors is associated with improved overall, and in many instances, disease-free, long-term survival. Metastatic colorectal carcinomas, metastatic neuroendocrine tumors, and metastatic gastrointestinal stromal tumors constituted 78% of resections because the largest body of literature and cumulative experience exists for these lesions. In contrast, breast carcinomas and pancreatic carcinomas, which are the next common metastatic liver tumors were biopsied but rarely resected, because metastasectomy is not the standard of care for these tumors. Immunohistochemistry was performed in less than a quarter of the total number of cases (23%), because the primary tumor site was known in the vast majority of cases. Of the 42 cases with unknown primary tumor, it was elucidated in 50% of the cases by immunohistochemical and clinical work-up. Of the cases with known primary tumor, immunohistochemistry was performed mostly in metastatic breast, colon, and lung carcinomas. In these cases, biomarker analyses provided additional information relevant to clinical management.

A proposed risk assessment score for gastrointestinal stromal tumors based on evaluation of 19,030 cases from the National Cancer Database.

BACKGROUND: Standard risk assessment algorithms for gastrointestinal stromal tumor (GIST) are based on anatomic and histopathological variables with arbitrarily defined subcategories. Our goal was to improve risk assessment for GIST through retrospective analysis of patient data. METHODS: The National Cancer Database (NCDB) was queried for patients with GIST; the final cohort consisted of 19,030 cases. Main outcomes were metastasis at presentation and overall survival. A test dataset was used to reevaluate risk stratification parameters in multivariate regression models. A novel risk assessment system was applied to the validation dataset and compared to other currently used risk assessment schemes. RESULTS: Analysis of observed prevalence of metastases at presentation suggested 7 cm and mitotic rates > 10 per 5 mm2 as optimal threshold values. A proposed risk stratification score showed statistical superiority compared to the National Comprehensive Cancer Network, American Joint Committee on Cancer, and modified National Institute of Health classifications in predicting probability of presentation with metastasis at diagnosis and 4-year overall survival after accounting for important covariables including patient age and comorbidities, year of diagnosis, and surgical/systemic therapeutic regimen. CONCLUSIONS: Reexamination of prognostic factors for GIST demonstrated that current threshold values for tumor size and mitotic rate are suboptimal. A risk stratification score based on revised categorization of these factors outperformed currently used risk assessment algorithms.

Imatinib and nutritional support can make successful treatment for a case of huge liver metastasis of duodenal gastrointestinal stromal tumor that initially showed jaundice and cachexia.

It is very difficult to treat patients with liver metastasis presenting with jaundice or cachexia. We herein report a successfully treated case of huge liver metastasis of gastrointestinal stromal tumor (GIST) that initially showed jaundice and cachexia. The patient was a woman in her early 40 s. She had a history of duodenal GIST 4 years before this admission. She was admitted to our hospital for abdominal fullness and anorexia. Abdominal computed tomography revealed huge liver metastasis of GIST. She showed jaundice and cancer cachexia with a modified Glasgow Prognostic Score of 2. After applying nutritional support, 400 mg of imatinib was administered. Although leg edema transiently worsened, the withdrawal of imatinib and administration of diuretics improved it. Imatinib was re-administered, and nutritional support was continued. The total bilirubin level decreased, and the serum albumin level increased. The tumor gradually decreased in size. Finally, she received surgical resection after 16 months of treatment with imatinib. Although adjuvant imatinib administration was continued after surgery, and no recurrence was observed as of 18 months after surgery.

Cost-Effectiveness Analysis of Tyrosine Kinase Inhibitors in Gastrointestinal Stromal Tumor: A Systematic Review.

Background: The introduction of tyrosine kinase inhibitor (TKI) therapy has dramatically improved the clinical effectiveness of patients with locally advanced and/or metastatic gastrointestinal stromal tumors (GIST), and this systematic review was conducted aiming at the cost-effectiveness analysis of TKIs in GIST. Methods: A thorough literature search of online databases was performed, using appropriate terms such as "gastrointestinal stromal tumor or GIST," "cost-effectiveness," and "economic evaluation." Data extraction was conducted independently by two authors, and completeness of reporting and quality of the evaluation were assessed. The systematic review was conducted following the PRISMA statement. Results: Published between 2005 and 2020, 15 articles were incorporated into the systematic review. For advanced GIST, imatinib followed by sunitinib was considered cost-effective, and regorafenib was cost-effective compared with imatinib re-challenge therapy in the third-line treatment. For resectable GIST, 3-year adjuvant imatinib therapy represented a cost-effective treatment option. The precision medicine-assisted imatinib treatment was cost-effective compared with empirical treatment. Conclusion: Although identified studies varied in predicted costs and quality-adjusted life years, there was general agreement in study conclusions. More cost-effectiveness analysis should be conducted regarding more TKIs that have been approved for the treatment of GIST. Systematic Review Registration: https://www.crd.york.ac.uk/, PROSPERO: CRD42021225253.

[Clinical diagnosis and treatment of gastrointestinal stromal tumor: matching technological breakthrough with patient care].

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the digestive tract. Although GIST has only been recognized as a separate entity for several decades, management strategies for GIST have changed dramatically over time. Advances in treatment have yielded dramatic successes in improving prognosis of patients with GIST. However, the meaningful progress also brings escalating social and economic burdens. There is a long distance between technological breakthroughs and its real benefits of society. Due to the rapid development in a short period, successful experience in disease diagnosis and treatment and the accompanying problems have appeared in a more concentrated and obvious manner. Any medical science exploration and practice initially aim to have the essence of humanism. As practitioners of medical technology, doctors should treat patients as a whole "human" in the process of diagnosis and treatment instead of just focusing on the technology itself. Moreover, doctors should comprehensively consider patients' physical, psychological and social attributes, pay attention to their physical, mental and social needs, find and try to solve problems, so as to promote the developement of medical science in the correct direction.

[Updates and interpretations of the NCCN Clinical Practice Guidelines (2019 6th version) on gastrointestinal stromal tumor].

The diagnosis and treatment of gastrointestinal stromal tumor (GIST) is getting more and more standardized. In the last two decades, due to the elucidation of molecular mechanism of tumorigenesis, as well as the effectiveness of tyrosine kinase inhibitors, GIST has become well-known as one of the most classical models of targeted therapy on solid tumors in the precision medicine era. The National Comprehensive Cancer Network (NCCN) issued the latest version of clinical practice guideline on soft tissue sarcoma in February 2020. Compared with previous versions, the new version of the guideline highlighted the treatment recommendations of avapritinib, which further promoted the precise targeted treatment of GIST.

[Analysis of imatinib trough concentration at steady state in adjuvant therapy of patients with high risk gastrointestinal stromal tumor].

Objective: To explore the features of imatinib mesylate (IM) plasma concentration during adjuvant therapy and clinical factors associated with IM plasma concentration in patients with high risk gastrointestinal stromal tumors (GIST), and to determine whether IM plasma concentration <1100 µg/L influences the efficacy of adjuvant therapy. Methods: A retrospective case control study method was used. Case inclusion criteria: (1) complete resection of lesion and GIST confirmed by pathology; (2) high risk classified according to modified National Institutes of Health classification system (2008); (3) administration of IM 400 mg/d for at least 1 month; (4) not taking the medication likely affecting IM pharmacokinetic, such as rifampicin, dilantin, and carbamazepine, within 1 month before blood collection. Data of GIST patients who visited GIST Disease - Oriented Outpatient, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology between January 2015 to December 2018 were retrospectively analyzed. After taking IM for 22-26 hours, 5 ml of peripheral venous blood was collected into EDTA anticoagulant tube. IM plasma concentration was detected by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Patients were divided into <1100 µg/L group and ≥1100 µg/L group according to plasma concentration. Linear regression was used to analyze the relevance between clinical features and IM plasma concentration. Parameters with normal distribution were analyzed by Pearson correlation coefficient, and parameters with non-normal distribution were analyzed by Spearman correlation. Kaplan-Meier survival curves and COX regression model were used for survival analysis. Results: Among the 85 patients enrolled in the study, 49 patients (57.6%) were male and 36 (42.4%) were female, with mean age of (51.9±11.0) years. The body mass index was (22.5±2.9) kg/m(2) and body surface area was (1.6±0.2) m(2). Thirty patients received gene test, including 23 patients with c-Kit exon 11 mutation, 4 with c-Kit exon 9 mutation, 1 with c-Kit exon 11 and 17 mutation and 2 without c-Kit or PDGFRA gene mutation. The mean IM plasma concentration was (1391.4±631.3) µg/L, and there were 32 patients with plasma concentration <1100 µg/L and 53 patients with plasma concentration ≥1100 µg/L. There were no statistically significant differences between the two groups in gender, age, body mass index, body surface area, hematological examination (white blood cells, albumin, alanine aminotransferase, aspartate aminotransferase and serum creatinine), tumor location, tumor size, mitotic counts, duration of adjuvant therapy and methods of operation (all P>0.05). Positive correlation between IM plasma concentration and serum creatinine was observed in linear regression analysis (r=0.297, P=0.007), but there were no correlations between IM plasma concentration and age (r=0.044, P=0.686), body mass index (r=0.066, P=0.547), body surface area (r=-0.010, P=0.924), white blood cells (r=-0.080, P=0.478), albumin (r=-0.065, P=0.563), alanine aminotransferase (r=0.114, P=0.308), aspartate aminotransferase (r=0.170, P=0.127) and duration of adjuvant therapy (ρ=0.060, P=0.586). There was no statistically significant difference in IM plasma concentration between patients with different genders (t=0.336, P=0.738) and patients with different surgical methods (F=0.888, P=0.451). Up to March 1, 2019. the median follow-up time was 30 (range 4-49) months. Tumor recurrence was detected in two patients with plasma concentration <1100 µg/L and two with plasma concentration ≥1100 µg/L. One recurrent patient with plasma concentration <1100 µg/L was detected to harbor c-Kit exon 11 and exon 17 mutations, and the other did not receive gene detection. Two recurrent patients with plasma concentration ≥1100 µg/L were both detected to harbor c-Kit exon 9 mutation. The 3-year relapse-free survival rate was 96.4% in the cohort, 96.2% in patients with plasma concentration <1100 µg/L, and 96.6% in patients with plasma concentration ≥1100 µg/L. No significant difference in relapse-free survival was observed between the two groups (P=0.204). Univariate Cox analysis showed that IM plasma concentration <1100 µg/L was not a risk factor for patients with high risk GIST (HR=0.238, 95% CI: 0.022-2.637, P=0.242). Conclusions: IM plasma concentration of adjuvant therapy in patients with high risk GIST varies with individual. Patients with higher level of serum creatinine are more likely to have a higher plasma concentration. A blood drug concentration standard of less than 1100 µg/L for advanced GIST patients may not influence the prognosis of patients with high risk GIST.

Mutational Testing in Gastrointestinal Stromal Tumor.

Targeted treatment has become a major modality in cancer management. Such cancer drugs are generally designed to treat tumors with certain genetic/genomic makeups. Mutational testing prior to prescribing targeted therapy is crucial in identifying who can receive clinical benefit from specific cancer drugs. Over the last two decades, gastrointestinal stromal tumors (GISTs) have evolved from histogenetically obscure to being identified as distinct gastrointestinal mesenchymal tumors with well-defined clinical and molecular characteristics, for which multiple lines of targeted therapies are available. Although the National Comprehensive Cancer Network (NCCN) strongly recommends mutational testing for optimal management of GIST, many GIST patients still have neither a mutation test performed or any mutation-guided cancer management. Here, we review the mutation-guided landscape of GIST, mutational testing methods, and the recent development of new therapies targeting GIST with specific mutations.

Analysis of imatinib trough concentration at steady state in adjuvant therapy of patients with high risk gastrointestinal stromal tumor / 中华胃肠外科杂志

Objective@#To explore the features of imatinib mesylate (IM) plasma concentration during adjuvant therapy and clinical factors associated with IM plasma concentration in patients with high risk gastrointestinal stromal tumors (GIST), and to determine whether IM plasma concentration <1100 μg/L influences the efficacy of adjuvant therapy.@*Methods@#A retrospective case control study method was used. Case inclusion criteria: (1) complete resection of lesion and GIST confirmed by pathology; (2) high risk classified according to modified National Institutes of Health classification system (2008); (3) administration of IM 400 mg/d for at least 1 month; (4) not taking the medication likely affecting IM pharmacokinetic, such as rifampicin, dilantin, and carbamazepine, within 1 month before blood collection. Data of GIST patients who visited GIST Disease - Oriented Outpatient, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology between January 2015 to December 2018 were retrospectively analyzed. After taking IM for 22-26 hours, 5 ml of peripheral venous blood was collected into EDTA anticoagulant tube. IM plasma concentration was detected by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Patients were divided into <1100 μg/L group and ≥1100 μg/L group according to plasma concentration. Linear regression was used to analyze the relevance between clinical features and IM plasma concentration. Parameters with normal distribution were analyzed by Pearson correlation coefficient, and parameters with non-normal distribution were analyzed by Spearman correlation. Kaplan-Meier survival curves and COX regression model were used for survival analysis.@*Results@#Among the 85 patients enrolled in the study, 49 patients (57.6%) were male and 36 (42.4%) were female, with mean age of (51.9±11.0) years. The body mass index was (22.5±2.9) kg/m2 and body surface area was (1.6±0.2) m2. Thirty patients received gene test, including 23 patients with c-Kit exon 11 mutation, 4 with c-Kit exon 9 mutation, 1 with c-Kit exon 11 and 17 mutation and 2 without c-Kit or PDGFRA gene mutation. The mean IM plasma concentration was (1391.4±631.3) μg/L, and there were 32 patients with plasma concentration <1100 μg/L and 53 patients with plasma concentration ≥1100 μg/L. There were no statistically significant differences between the two groups in gender, age, body mass index, body surface area, hematological examination (white blood cells, albumin, alanine aminotransferase, aspartate aminotransferase and serum creatinine), tumor location, tumor size, mitotic counts, duration of adjuvant therapy and methods of operation (all P>0.05). Positive correlation between IM plasma concentration and serum creatinine was observed in linear regression analysis (r=0.297, P=0.007), but there were no correlations between IM plasma concentration and age (r=0.044, P=0.686), body mass index (r=0.066, P=0.547), body surface area (r=-0.010, P=0.924), white blood cells (r=-0.080, P=0.478), albumin (r=-0.065, P=0.563), alanine aminotransferase (r=0.114, P=0.308), aspartate aminotransferase (r=0.170, P=0.127) and duration of adjuvant therapy (ρ=0.060, P=0.586). There was no statistically significant difference in IM plasma concentration between patients with different genders (t=0.336, P=0.738) and patients with different surgical methods (F=0.888, P=0.451). Up to March 1, 2019. the median follow-up time was 30 (range 4-49) months. Tumor recurrence was detected in two patients with plasma concentration <1100 μg/L and two with plasma concentration ≥1100 μg/L. One recurrent patient with plasma concentration <1100 μg/L was detected to harbor c-Kit exon 11 and exon 17 mutations, and the other did not receive gene detection. Two recurrent patients with plasma concentration ≥1100 μg/L were both detected to harbor c-Kit exon 9 mutation. The 3-year relapse-free survival rate was 96.4% in the cohort, 96.2% in patients with plasma concentration <1100 μg/L, and 96.6% in patients with plasma concentration ≥1100 μg/L. No significant difference in relapse-free survival was observed between the two groups (P=0.204). Univariate Cox analysis showed that IM plasma concentration <1100 μg/L was not a risk factor for patients with high risk GIST (HR=0.238, 95% CI: 0.022-2.637, P=0.242).@*Conclusions@#IM plasma concentration of adjuvant therapy in patients with high risk GIST varies with individual. Patients with higher level of serum creatinine are more likely to have a higher plasma concentration. A blood drug concentration standard of less than 1100 μg/L for advanced GIST patients may not influence the prognosis of patients with high risk GIST.

Underuse of exon mutational analysis for gastrointestinal stromal tumors.

BACKGROUND: Tyrosine kinase inhibitors (TKI) have become the guideline-recommended therapy for high-risk resected and advanced gastrointestinal stromal tumors (GISTs). Exon mutational analysis (EMA) is used to inform pretherapy response to TKI and may predict overall prognosis. Despite these benefits, EMA remains underused, and its impact on TKI therapy decision-making remains unexplored. MATERIALS AND METHODS: A retrospective cohort was established from 104 patients receiving treatment for GISTs from 2006 to 2017. Current National Comprehensive Cancer Network guidelines indicate that EMA should be considered for all patients undergoing TKI therapy to identify genotypes that are likely, or unlikely, to respond to treatment. We first tracked guideline-considered EMA use and subsequent impact on treatment decision-making. A questionnaire was then administered to gastrointestinal medical oncologists to assess EMA perception. RESULTS: Among 104 GIST patients, 54 (52%) received TKI therapy. Of these, only 22 (41%) received EMA. Informed by EMA, treatment decisions included 59% who continued with original TKI therapy, 32% who switched to an alternative TKI, and 9% who discontinued or received no TKI. Although 92% of physicians indicated EMA was a valuable tool, only 62% indicated they used it "frequently" or "always" to inform treatment decisions. CONCLUSIONS: Less than half of patients receiving TKI therapy for GISTs received EMA at a comprehensive cancer center. Despite this low uptake, when it was performed, EMA guided alternative treatment decision in 41% of patients. Physician survey responses indicated that interventions targeting physician education and an electronic medical record reminder may improve EMA uptake.

Moderate intensity low frequency rotating magnetic field inhibits breast cancer growth in mice.

Moderate intensity low frequency rotating magnetic field (LF-RMF) has been shown to inhibit melanoma, liver and lung cancer growth in mice. However, its effects on other types of cancers have not been investigated in vivo. Here, we show that 0-0.15T moderate intensity 4.2 Hz LF-RMF can inhibit tumor growth in mice bearing MDA-MB231 and MCF7 human breast cancer cells by over 30%. In contrast, the human gastrointestinal stromal tumor GIST-T1 growth was not inhibited by LF-RMF. In all RMF treatments, there were no apparent adverse effects on mice organs, body weight or water/food consumptions. However, the alanine aminotransferase (ALT) level was decreased in LF-RMF-treated mice bearing MCF7 and GIST-T1 cells, which indicated alleviated liver damage. Therefore, our study shows that moderate intensity LF-RMF might be a safe physical method that has clinical potentials to be used to inhibit breast cancer growth in the future.

Laparoscopic Versus Open Resection for Gastrointestinal Stromal Tumors (GISTs).

PURPOSE: Primary gastrointestinal stromal tumors (GISTs) are typically treated with open resection. There is growing interest in laparoscopic GIST resection; however, data is limited. We report our experience with GIST resections using both open and laparoscopic techniques. MATERIALS AND METHODS: Twenty-nine GIST patients underwent definitive intent resection at the University of Missouri from 1990 to 2010. Patients who underwent laparoscopic resection (n = 7) were matched on the basis of tumor size, age, tumor location, and National Comprehensive Cancer Network (NCCN) risk stratification with seven patients who underwent open resection. The two groups were compared with respect to age, gender, BMI, tumor size, tumor site, mitotic rate, surgical margins, NCCN risk stratification, estimated blood loss, hospital stay, surgical complications, disease recurrence, and overall survival. RESULTS: The cohorts did not differ with respect to age, gender, BMI, tumor location, tumor size, or positive margins (p > 0.05). Patients who underwent open resection had more NCCN high-risk patients, but the difference was not statistically significant (p = 0.08). There was significantly less estimated blood loss (median 15 vs. 150 mL, p < 0.05) and significantly shorter hospital stay (median 4 vs. 7 days, p < 0.05) for the laparoscopy group. There were no recurrences in the laparoscopy group, but there was one in the open group with a median follow-up of 55 and 63 months, respectively (p > 0.05). Five-year disease-free survival was 100 % for the laparoscopic group and 83 % for the open resection group. CONCLUSIONS: Laparoscopic resection for appropriately selected GISTs is feasible and associated with significantly less blood loss and shorter hospitalizations compared to open resection. Further studies are needed to better define its role for GIST.

Brunner's gland cyst in combination with gastrointestinal stromal tumor: A case report.

Brunner's gland cysts are rare benign lesions that are mainly observed in the first and the second regions of the duodenum. Patients with Brunner's gland cyst demonstrate no specific symptoms. The present study reports the case of a patient with Brunner's gland cyst located in the duodenum in combination with a gastrointestinal stromal tumor (GIST) in the same region. To the best of our knowledge, the present study reports the first case of Brunner's gland cyst with GIST. A 58-year-old female patient was referred to Tianchang Hospital of Traditional Chinese Medicine (Tianchang, China) with a one-month history of upper abdominal discomfort, diarrhea and recurrent vomiting following the intake of food. Upper gastrointestinal endoscopy and a computed tomography scan revealed the presence of a round, cystic-like lesion with internal low density located within the duodenum. Pathological examination revealed that the cyst measured 0.3 cm in diameter and was consistent with a diagnosis of Brunner's gland cyst. Histopathology revealed that the cyst possessed characteristics of GIST. The patient underwent surgical exploration and tumor resection, and was discharged 2 weeks post-surgery. During the 12 month post-operative follow-up period, the outcome of the patient was good. This case study of Brunner's gland cyst combined with GIST enriches the present literature and promotes better understanding of the two diseases. Further investigation is required to explain the mechanism and association between the two rare diseases.

The standard diagnosis, treatment, and follow-up of gastrointestinal stromal tumors based on guidelines.

Although gastrointestinal stromal tumors (GISTs) are a rare type of cancer, they are the commonest sarcoma in the gastrointestinal tract. Molecularly targeted therapy, such as imatinib therapy, has revolutionized the treatment of advanced GIST and facilitates scientific research on GIST. Nevertheless, surgery remains a mainstay of treatment to obtain a permanent cure for GIST even in the era of targeted therapy. Many GIST guidelines have been published to guide the diagnosis and treatment of the disease. We review current versions of GIST guidelines published by the National Comprehensive Cancer Network, by the European Society for Medical Oncology, and in Japan. All clinical practice guidelines for GIST include recommendations based on evidence as well as on expert consensus. Most of the content is very similar, as represented by the following examples: GIST is a heterogeneous disease that may have mutations in KIT, PDGFRA, HRAS, NRAS, BRAF, NF1, or the succinate dehydrogenase complex, and these subsets of tumors have several distinctive features. Although there are some minor differences among the guidelines--for example, in the dose of imatinib recommended for exon 9-mutated GIST or the efficacy of antigen retrieval via immunohistochemistry--their common objectives regarding diagnosis and treatment are not only to improve the diagnosis of GIST and the prognosis of patients but also to control medical costs. This review describes the current standard diagnosis, treatment, and follow-up of GISTs based on the recommendations of several guidelines and expert consensus.

Optimizing tyrosine kinase inhibitor therapy in gastrointestinal stromal tumors: exploring the benefits of continuous kinase suppression.

The oral tyrosine kinase inhibitor (TKI) imatinib has revolutionized the treatment of gastrointestinal stromal tumors (GISTs), most of which harbor oncogenic mutation in genes that encode the receptor tyrosine kinases KIT or PDGFA. Imatinib is the standard of care for patients with advanced GIST and for patients with primary GIST at significant risk of recurrence after surgery. Design. This review discusses data supporting continuous kinase suppression with imatinib and key issues, including response to imatinib reintroduction, effect of treatment interruption on secondary resistance to imatinib, and prognostic factors associated with sustained response to imatinib. Results. Long-term follow-up results of the B2222 study and updated results of the BFR14 trial demonstrate that continuous imatinib treatment in patients with advanced GIST is associated with reduced risk of progression. For patients progressing on or intolerant of imatinib, continuing therapy with TKIs sunitinib followed by regorafenib is recommended. In the adjuvant setting, final results of the trial by the Scandinavian Sarcoma Group and the Sarcoma Group of the Arbeitsgemeinschaft Internistische Onkologie demonstrate that 3 years of adjuvant imatinib, compared with 1 year, significantly reduces the risk of recurrence and improves overall survival of patients with KIT-positive GIST at high risk of recurrence. Conclusions. Maintenance of therapy with TKIs is the key to successful treatment of GIST. Results from recent studies provide a strong rationale for continuous imatinib treatment for 3 years following surgical resection and long-term continuous administration in advanced or metastatic GIST.