The epidemiologic, health-related quality of life, and economic burden of gastrointestinal stromal tumours

Utility of noncontrast MRI in the detection and risk grading of gastrointestinal stromal tumor: a comparison with contrast-enhanced CT

Background

Recently developed adjuvant therapies for gastrointestinal stromal tumor (GIST) have been shown to improve patient survival. Guidelines currently recommend contrast-enhanced computed tomography (CECT) for GIST detection and surveillance. Patients with moderate-to-high risk GISTs require more frequent surveillance due to a higher 5-year recurrence rate. Our study aimed to compare noncontrast magnetic resonance imaging (MRI) with CECT for GIST detection, and evaluate volumetric apparent diffusion coefficients (ADCs) for risk stratification of GIST.

Methods

We retrospectively enrolled 83 patients with histopathologically confirmed GISTs for lesion detection efficiency analysis between noncontrast MRI and matched CECT studies. A 5-point scale was used by two independent reviewers to determine if the lesion was present or absent. Another cohort, comprising 28 patients with pathologically confirmed primary GISTs, was further screened for risk stratification, with a comparison of volumetric ADC parameters between the pathologically very-low-to-low risk and moderate-to-high risk GIST patients.

Results

For identifying GISTs, the sensitivity and specificity of noncontrast MRI were 83.6% and 89.3% for reader 1 respectively, and 81.8% and 92.9% for reader 2 respectively; the sensitivity and specificity of CECT were 76.4% and 89.3% for reader 1 respectively, and 76.4 and 78.6% for reader 2 respectively. Tumor volumetric ADC histogram parameters, including ADC_max, ADC_stdev, 90^th and 95^th percentiles, inhomogeneity, and entropy, were positively correlated with a higher risk grade of GIST (r=0.421-0.758). The receiver operator characteristic curve analysis showed ADC_max achieved the highest area under the curve value of 0.938 for discriminating very-low-to-low risk versus moderate-to-high risk GISTs.

Conclusions

Noncontrast MRI was an efficient technique for identifying GIST patients. The combination of CECT and noncontrast MRI can improve the reliability of diagnosis. For patients with contraindications to CECT, noncontrast MRI may be a comparable alternative. Volumetric ADC histogram parameters may be useful in differentiating very-low-to-low risk from moderate-to-high risk primary GISTs.

The Role of Surgical Resection Following Tyrosine Kinase Inhibitors Treatment in Patients with Advanced Gastrointestinal Stromal Tumors: A Systematic Review and Meta-analysis

Background The benefit of surgical resection for advanced gastrointestinal stromal tumors (GISTs) following tyrosine kinase inhibitors (TKIs) treatment was still under debate. The present meta-analysis was designed to assess the value of surgical resection for the prognosis of patients with metastatic, recurrence and unresectable GISTs. Methods A systematic search of PubMed Central, PubMed, EMBASE and the Cochrane Library database was performed. Relevant studies of the role of surgery in advanced GISTs published before 1 May 2019 were identified. The quality of studies was assessed by the Newcastle-Ottawa Quality Assessment Scale. The progression-free survival (PFS) and overall survival (OS) were assessed through software Stata 15.0. Results A total of 6 retrospective studies including 655 patients were analyzed. The pooled result revealed that surgical resection group was associated with better PFS (HR = 2.08; 95% CI: 1.58 to 2.76; P<0.001) and better OS (HR = 2.13; 95% CI: 1.59 to 2.85; P<0.001) compared with TKIs treatment alone group. Conclusions Surgical resection following TKIs treatment could significantly improve the prognosis of patients with advanced GISTs.

A Critical Review of the Impact of Sarcoma on Psychosocial Wellbeing

Background

Previous reviews of outcomes in specific sarcoma populations suggest patients have poor quality of life. In most of these reviews, there is a predominant focus on physical function rather than psychosocial outcome. The aim of this review was to describe the psychosocial impact of diagnosis and treatment on patients with all types of sarcoma.

Methods

Searches were conducted through six electronic databases for publications of any study design using a validated patient-reported outcome measure reporting the psychosocial impact in this population.

Results

Eighty-two studies fulfilled the inclusion criteria. Most (65%) were assessed of being of reasonable quality. The most common aspect of psychosocial wellbeing measured was quality of life (80%). Due to the heterogeneity of methods, outcomes, and populations, it was not possible to make definitive conclusions. It seems there is an improvement in the physical aspects of quality of life over time but not in psychosocial function or mental health. There was no change in mental health scores, but patients reported an improvement in adjusting to normal life. There are no differences according to the type of surgery patients receive, and psychosocial outcomes tend to be poorer than the general population. There is no consistency in identifying the factors that predict/influence psychosocial wellbeing.

Conclusion

The published literature does not provide a clear understanding of the impact of sarcoma diagnosis and treatment on psychosocial wellbeing. Instead, the review demonstrates a need for well-designed studies in this area and a more consistent approach to the measurement of patient-reported outcomes, which include psychosocial domains. Recommendations for future research have been proposed.

Comparison of three prognostic models for predicting cancer-specific survival among patients with gastrointestinal stromal tumors

AIM

To evaluate the predictive value for cancer-specific survival of the models of the American Joint Committee on Cancer (AJCC) stage, NIH and Armed Forces Institute of Pathology (AFIP) among patients with gastrointestinal stromal tumors (GISTs).

METHODS

Surveillance, Epidemiology and End Results database (2010-2014) was accessed. Overall survival analysis and adjusted cancer-specific Cox regression hazard was calculated.

RESULTS

For gastric GISTs, concordance-index according to AJCC was 0.834; according to NIH was 0.833; according to AFIP was 0.836. Concordance-index for nongastric GISTs according to AJCC was 0.800, according to NIH was 0.801 and according to AFIP was 0.799.

CONCLUSION

The performance of the three models is comparable with regards to cancer-specific survival prediction.

Ki67 is a biological marker of malignant risk of gastrointestinal stromal tumors: A systematic review and meta-analysis

BACKGROUND

Ki67 is a good marker of cell proliferation in a variety of tumors. High ki67 levels are usually associated with poor prognosis. However, the relationship between Ki67 expression and the risk of malignancy of gastrointestinal stromal tumors (GISTs) is still poorly defined. The current meta-analysis was initiated to address this issue.

METHODS

Studies reporting Ki67 expression and the risk of malignancy in GIST were found by searching Cochrane Library, PubMed, Medline, and Embase until October 31, 2016. A total of 9 studies involving 982 patients were included. Pooled odds ratio (OR) estimates and 95% confidence intervals (CIs) were calculated using a fixed-effect model.

RESULTS

Meta-analysis showed no significant difference in the incidence of Ki67 overexpression between the very low NIH group and the low NIH group (OR: 0.66, 95% CI: 0.25-1.76; P = .41, Pheterogeneity = .25). However, the incidence of Ki67 overexpression gradually increased from the low NIH group to the high NIH group (OR: 0.46, 95% CI: 0.27-0.80; P = .005, Pheterogeneity = .13) and (OR: 0.22, 95% CI: 0.15-0.34; P < .00001, Pheterogeneity = .33).

CONCLUSIONS

There were more GIST patients with Ki67 overexpression in the intermediate and high NIH groups than in the low NIH group. Ki67 overexpression may be a useful marker of the risk of malignant GIST transformation.

Compound gastroenteropancreatic neuroendocrine and gastrointestinal stromal tumors in the stomach: A case report

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) combined with gastrointestinal stromal tumors (GISTs) are rarely observed in the clinic. In the present study, the case of a 56-year-old female diagnosed with compound GEP-NETs and GISTs was reported. The patient initially presented with epigastric discomfort. The pre-operative diagnosis was of GISTs based on the endoscopic and imaging findings. A subtotal gastrectomy and Roux-en-Y reconstruction were successfully performed. The final diagnosis was revised to be compound GEP-NETs and GISTs based on the pathological findings. After 17 months of follow-up examinations using computed tomography and ultrasonography, the patient showed no symptoms or signs of recurrence.

Hypoglycemia Associated with a Gastrointestinal Stromal Tumor Producing High-molecular-weight Insulin Growth Factor II: A Case Report and Literature Review

A 61-year-old woman with multiple metastatic and unresectable gastrointestinal stromal tumors (GISTs) was referred for investigation of refractory hypoglycemia that developed four months before this hospitalization. On admission, her fasting plasma glucose was 38 mg/dL despite 10% glucose infusion. Investigations revealed that her serum C-peptide, insulin and growth hormone levels were suppressed, and big insulin-like growth factor II was observed. She was diagnosed with non-islet cell tumor hypoglycemia, which resolved after glucocorticoid treatment. Clinicians should thus be vigilant to identify hypoglycemia in patients with large metastatic GISTs because glucocorticoid therapy is useful even if the GIST is inoperable.

Therapeutic value of endoscopic submucosal dissection for gastric muscularis propria tumors

AIM: To evaluate the safety and efficacy of endoscopic submucosal dissection (ESD) for tumors originating from the gastric muscularis propria.

METHODS: Forty-two patients with tumors originating from the gastric muscularis propria who underwent endoscopic therapy between January 2013 and January 2015 were included. The complications, clinicopathological data, and postoperative follow-up data were analyzed.

RESULTS: Of the 42 patients, 20 were managed by ESD, 15 by endoscopic submucosal excavation (ESE), and 7 by endoscopic full-thickness resection (EFR). Four cases underwent surgery for unsuccessful endoscopic resection, including three cases receiving laparoscopic surgery for difficulties in en bloc removal or perforation, and 1 case receiving open surgery because of uncontrolled bleeding, and the success rate was 90.48%. Delayed hemorrhage occurred in two patients and no delayed perforation occurred. All the complications were successfully managed by endoscopic intervention and conservational therapy. Seven cases of active perforation in the EFR group were all successfully managed by endoscopy. The post-operative follow-up period ranged from 6 to 28 mo. No local recurrence or distant metastasis occurred.

CONCLUSION: ESD is an effective procedure for tumors originating from the gastric muscularis propria, and laparoseopic intervention is necessary for en bloc resection in some cases.

Meta-analysis for the association between overall survival and progression-free survival in gastrointestinal stromal tumor

PURPOSE

Gastrointestinal stromal tumor (GIST) is a relatively rare tumor that is treated with targeted therapies in advanced stages. Randomized clinical trials (RCT) often require long follow-up and large sample sizes to evaluate overall survival (OS), the gold-standard measure of treatment efficacy. However, changes in therapy following disease progression may complicate survival assessments. Establishing surrogate endpoints may facilitate the drug approval and availability of new efficacious treatments; however, no published studies have investigated this topic in unresectable and/or metastatic GIST.

EXPERIMENTAL DESIGN

A systematic literature review identified 14 RCTs and five observational studies of sufficient methodologic quality published between January 1995 and December 2013 (29 treatment arms; 2,189 patients). Weighted linear regression was used to evaluate the relation between median OS and median progression-free survival (PFS) for all arms combined and stratified by treatment line, treatment type, and quality score.

RESULTS

Median OS and PFS were positively related with a correlation of 0.91. The association was still moderate (correlation 0.72) after eliminating four influential data points. In stratified analyses, correlation of OS and PFS was greater in later lines of therapy (first line = 0.52; second line = 0.80; third- and later-line = 0.70) and imatinib showed a stronger association (0.91) than other evaluated treatments (-0.26 to 0.69).

CONCLUSION

This analysis identified a strong relationship between median OS and PFS, especially in later lines of therapy. Findings suggest that PFS could serve as a surrogate marker for OS; however, analyses of patient-level data are needed to establish its validity in GIST.

Optimizing surgical and imatinib therapy for the treatment of gastrointestinal stromal tumors

INTRODUCTION

The discovery of activating KIT and PDGFRα mutations in gastrointestinal stromal tumors (GISTs) represented a milestone as it allowed clinicians to use tyrosine kinase inhibitors, like imatinib, to treat this sarcoma. Although surgery remains the only potentially curative treatment, patients who undergo complete resection may still experience local recurrence or distant metastases. Therapeutic strategies that combine surgical resection and adjuvant imatinib may represent the best treatment to maximize patient outcomes. In addition to the use of imatinib in the adjuvant and metastatic settings, neoadjuvant imatinib, employed as a cytoreductive therapy, can decrease tumor volume, increase the probability of complete resection, and may reduce surgery-related morbidities. Thus, selected patients with metastatic disease may be treated with a combination of preoperative imatinib and metastasectomy. However, it is critical that patients with GIST be evaluated by a multidisciplinary team to coordinate surgery and targeted therapy in order to maximize clinical outcomes.

DISCUSSION

Following a systematic literature review, we describe the presentation, diagnosis, and treatment of GIST, with a discussion of the risk assessment for imatinib therapy. The application of surgical options, combined with adjuvant/neoadjuvant or perioperative imatinib, and their potential impact on survival for patients with primary, recurrent, or metastatic GIST are 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.

Endoscopic muscularis dissection for upper gastrointestinal subepithelial tumors originating from the muscularis propria

BACKGROUND AND AIMS

Based on our experience with endoscopic submucosal dissection (ESD) and new endoscopic techniques for endoscopic closure of iatrogenic upper gastrointestinal (upper-GI) perforations, we developed methods to remove upper-GI subepithelial tumors (SETs) originating from the muscularis propria by endoscopic muscularis dissection (EMD). The aim of this study is to evaluate the clinical feasibility and safety of EMD.

METHODS

31 patients with upper-GI SETs originating from the muscularis propria were treated by EMD. The EMD differed from ESD in (1) precutting the overlying mucosa above the lesion by using snare or longitudinal incision instead of circumferential incision, (2) dissecting the complete tumors away from submucosal and muscularis propria tissue by electrical dissection combined with blunt dissection, and (3) closing the wound with clips. Perforations occurring during dissection were closed by endoscopic methods.

RESULTS

30 of 31 tumors were resected completely (96.8 %). One esophageal lesion was resected partially because of severe adhesions with surrounding tissue. Mean resected tumor size was 22.1 mm × 15.5 mm, and mean operation time was 76.8 min (range 15-330 min). Histological diagnosis was gastrointestinal stromal tumor (GIST) in 16 lesions [6 esophageal, 3 cardial, 7 gastric; 6 very low risk and 10 low risk according to the National Institutes of Health (NIH) risk classification] and leiomyoma in 15 lesions (8 esophageal, 4 cardial, 3 gastric). No patient developed delayed hemorrhage. Perforation occurred in four patients (12.9 %), all of which were managed successfully by endoscopic techniques. The mean follow-up time was 17.7 months (range 7-35 months). Follow-up found no tumor recurrence in any patient.

CONCLUSIONS

In this early experience, EMD appears to be a feasible and minimally invasive treatment for some patients with upper-GI SETs originating from the muscularis propria. Although there is a higher risk of perforation than with ESD, this will improve with extended practice, and perforations have become manageable endoscopically.

Effectiveness of adjuvant imatinib in patients with gastrointestinal stromal tumor: results of a population-based, matched-cohort study

OBJECTIVE

Data are limited on the use of adjuvant imatinib in patients with gastrointestinal stromal tumor (GIST) outside of clinical trials. This retrospective, population-based, matched-cohort study evaluated adjuvant imatinib treatment patterns, assessed impact on clinical outcomes, and estimated effectiveness based on number needed to treat (NNT).

RESEARCH DESIGN AND METHODS

GIST-related claims from the PharMetrics claims database were included (2000-2010). A stepwise identification algorithm identified appropriate patients based on GIST-related ICD-9-CM codes, who were classified as 'imatinib (IM) patients' receiving imatinib within 84 days post-surgery and 'non-imatinib (non-IM) patients' undergoing surgery but not receiving imatinib during the study period. The primary composite outcome was based on incidence of a second GIST-related surgery and long-term follow-up in the matched cohorts. IM patients were matched with up to eight non-IM patients on age, gender, ICD-9-CM code, and first surgery date.

RESULTS

A total of 118 IM and 4088 non-IM patients with possible GIST ICD-9s and surgery were included. The median duration between first and second surgeries was significantly longer in IM than non-IM patients (488 vs. 290 days; p = 0.0005). IM patients also had longer median follow-up from initial surgery to composite outcome (433 vs. 320 days; p = 0.002). Adherence to IM, measured by medication possession ratio, was 0.83 and 0.73 during the first and second years of treatment, respectively. IM patients were less likely to have the composite outcome compared with non-IM patients (hazard ratio = 0.501; p = 0.0005). The NNT to prevent one outcome was 4.

CONCLUSIONS

Patients receiving adjuvant imatinib treatment were less likely to have second surgery or be lost to follow-up, and had a longer interval to second surgery. Although treatment with adjuvant imatinib in patients with primary GIST is effective, adherence to imatinib and treatment duration are less than recommended by current treatment guidelines.

Iron as a target of chemoprevention for longevity in humans

Iron is universally abundant and no life can exist without it. However, iron levels should be maintained within a narrow range. Iron deficiency causes anaemia, whereas excessive iron increases cancer risk, presumably by free radical generation. Several pathological conditions such as genetic haemochromatosis, chronic viral hepatitis B and C, conditions related to asbestos fibre exposure and ovarian endometriosis have been recognized as iron overload-associated conditions that also increase human cancer risks. Iron's carcinogenicity has been documented in animal experiments. Surprisingly, these studies have revealed that the homozygous deletion of CDKN2A/2B is a major hallmark of iron-induced carcinogenesis. Recently, the hormonal regulation of iron metabolism has been elucidated. A commonly hypothesized mechanism may be the lack of any iron disposal pathway other than for bleeding and a mechanism of iron re-uptake as catechol chelate has been discovered. Iron overload in neurons via the ferroportin block may play a role in Alzheimer's disease. Furthermore, a recent epidemiological study reported that iron reduction by phlebotomy was associated with decreased cancer risks in a general population. Given that the required amounts of iron decrease during ageing, the fine control of body iron stores would be a wise strategy for chemoprevention of several diseases.

Evaluation of self-reported progression and correlation of imatinib dose to survival in patients with metastatic gastrointestinal stromal tumors: an open cohort study

Objectives

Self-reported progression was evaluated as a predictor of survival in patients with metastatic gastrointestinal stromal tumor (GIST).

Methods

This is a follow-up of an open cohort study of Life Raft Group (LRG) members with a diagnosis of KIT-positive metastatic GIST receiving imatinib from May 2000–December 2007 reporting their subjective response to therapy by completion of an internet-based questionnaire. Subjects received ≥ 1 year of imatinib and reported an initial positive response. Members reporting stable disease or progression were excluded. Self-reported progression-free survival (srPFS) was compared with overall survival (OS) and analyzed by starting and last reported dose.

Results

One hundred sixty-nine subjects reported a mean starting dose of 527.8±177.9 mg/d at a mean age of 53.8±11.6 years at initial diagnosis. Of those reporting progression, 66% died versus 11% of those not reporting progression (P < 0.0001). When analyzed by last reported dose, a median srPFS benefit of 27.3 months was observed for the >400 mg/d group (P = 0.0017). Sixty-two percent of subjects who initiated therapy at >400 mg/d reported a dose reduction. When analyzed by last reported dose, a significant benefit in OS (P = 0.0229) and srPFS (P = 0.0069) was observed for subjects taking 600 over 400 mg/d.

Conclusions

srPFS strongly correlated with OS. Significant advantages were observed when last reported dose was considered, as was higher daily dose. These observations suggest that careful escalation to intermediate daily doses should be investigated further for its potential to reduce the incidence and severity of adverse events, but also as a strategy against developing secondary resistance to imatinib.

Gastrointestinal Stromal Tumors: A Guide to the Diagnosis

Gastrointestinal stromal tumors (GISTs) have emerged from being a poorly understood and therapeutically refractory sarcoma to a tumor whose biology has not only provided insight into a mechanism of oncogenesis but has also led to a rational basis for therapy. Most GISTs are characterized by KIT protein (CD117) expression and constitutive activating mutations in either the c-kit or platelet-derived growth factor receptor α genes. This information can now be obtained from routine formalin-fixed and paraffin-embedded tissue. Because the correct diagnosis is the key to successful treatment of this tumor, it is incumbent on the pathologist to be familiar with the various gross and histologic patterns shown by these tumors. GISTs range from small incidental stromal nodules to large cystic and solid tumor masses. GISTs show a variety of microscopic patterns and therefore several other tumors enter the differential diagnosis. Fortunately, with an understanding of GIST histology, and with the proper use of immunohistochemistry and molecular analysis, a correct diagnosis can usually be made. In addition to the correct diagnosis, several key attributes of the tumor need to be determined because they provide the basis for proper clinical management. This article summarizes the gross, microscopic, and molecular findings of GISTs, and discusses the differential diagnosis and key attributes of this interesting group of neoplasms.

Pharmacological management of gastrointestinal stromal tumours: an update on the role of sunitinib

The efficacy and tolerability of the receptor tyrosine kinase inhibitor, sunitinib malate, have been demonstrated in phase I-III clinical trials of patients with imatinib-resistant or imatinib-intolerant gastrointestinal stromal tumours (GIST) as well as in a worldwide expanded-access study and in a continuous daily dosing (CDD) trial. Tumour genotype may have a significant influence on the activity of sunitinib in patients with imatinib-resistant GIST. Sunitinib activity was observed across different GIST genotypes and particularly in patients with wild-type and KIT exon 9 mutations (all relatively resistant to standard-dose imatinib) and in patients with secondary KIT exons 13 and 14 mutations. Adverse events with sunitinib were generally mild to moderate and easily managed by dose reduction, dose interruption or standard supportive measures. Treatment discontinuation can be avoided in most patients by close monitoring before and during treatment with appropriate adverse event management as necessary. The correlation between treatment exposure and clinical response is prompting the search for new approaches to treatment optimisation to ensure that patients derive maximum benefit from sunitinib therapy, including dose adjustments based on blood testing to ensure optimal drug exposure, and the use of the alternative CDD regimen to avoid treatment interruption.

Sorafenib induces growth suppression in mouse models of gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Current therapeutic options include surgery and targeted molecular approaches such as imatinib and sunitinib. Our aim was to establish patient-derived GIST xenografts for the use of screening new drugs and improving current treatment regimens used in GIST. In this present study, we investigate the antitumor activity of sorafenib against patient-derived GIST xenografts. Murine xenograft models were given two oral doses of sorafenib daily for 30 days and growth of established tumor xenografts was monitored at least twice weekly by vernier caliper measurements. Western blotting was then used to determine changes in proteins in these xenografts before and after sorafenib therapy. Apoptotic and cell proliferation were analyzed by immunohistochemisty. Our data found that oral administration of sorafenib to mice, bearing patient-derived GIST xenografts, resulted in dose-dependent inhibition of tumor growth. Sorafenib-induced growth inhibition was associated with decreased cell proliferation, increased apoptosis, and reduction in tumor angiogenesis. Western blot analysis revealed that sorafenib inhibited C-Raf, phospho-extracellular signal-regulated kinase 1/2, and phospho-MEK1 (Thr286) slightly as well as phospho-c-Kit (Tyr568/Tyr570), phospho- platelet-derived growth factor receptor beta (Tyr1021), and phospho-Flk1 (Tyr951), suggesting that sorafenib inhibited GIST growth by blocking the Raf/MEK/extracellular signal-regulated kinase pathway and angiogenesis. Sorafenib also induced cell cycle arrest, evident through increased levels of p15 and p27 and decreased levels of p21, cyclin A, cyclin B1, and cdc-2. Our study provides a strong rationale for the clinical investigation of sorafenib in patients with GIST as well as an established platform for further drug evaluation studies using GIST xenograft models.

Role of imatinib in the management of early, operable, and advanced GI stromal tumors (GISTs)

Gastrointestinal stromal tumors (GISTs), the most common sarcoma of the GI tract, have unique kinase mutations that serve as targets for medical therapy. This article reviews the data supporting the use of the tyrosine kinase inhibitor (TKI) imatinib in GIST patients, and how this treatment should be combined with surgical resection (when possible) to optimize patient outcomes. Although surgical resection remains the mainstay of treatment for these tumors, patients with resected GISTs have high relapse rates that can be reduced by 1 year of adjuvant imatinib. Data also support the use of imatinib for patients with recurrent or unresectable GIST. In these patients the drug should be continued until progression, intolerance, or the patients are rendered resectable. Patients with advanced GIST who are successfully resected after imatinib treatment should be placed back on imatinib postoperatively. Patients who develop generalized progression (progression at 2 or more sites) on imatinib should move to other treatments, such as newer TKIs or other targeted approaches currently under study. Genotyping of the tumor should be considered in all pediatric GISTs and high risk adult GISTs, especially if there is progression on imatinib. Quality of life and the cost/benefit of new therapies are important issues for further study in patients with GIST.