Tumor mitotic rate, size, and location independently predict recurrence after resection of primary gastrointestinal stromal tumor (GIST)

Laparoscopic Versus Open Resection for Gastric Gastrointestinal Stromal Tumors (GISTs): A Size-Location-Matched Case-Control Study

BACKGROUND

Laparoscopic resection for gastric gastrointestinal stromal tumors (GISTs) is technically feasible, but the long-term effect remains uncertain. This study aims to compare the long-term oncologic outcomes of laparoscopic versus open resection of GISTs by larger cases based on tumor size-location-matched study.

METHODS

Between 2006 and 2015, 63 consecutive patients with a primary gastric GIST undergoing laparoscopic resection were enrolled in and matched (1:1) to patients undergoing open resection by tumor size and location. Clinical and pathologic parameters and surgical outcomes associated with each surgical type were collected and compared.

RESULTS

The operation time, intraoperative blood loss, return of bowel function and oral intake, nasogastric tube retention time and postoperative stay were all shorter/faster in laparoscopic group than those in open group (P < 0.001). Postoperative complications were comparable except for the higher incidence of abdominal/incision pain in open group (9.52 vs 27%, P = 0.01). There was no statistical difference in recurrence rate (9.52 vs 15.87%, P = 0.29) and long-term recurrence-free survival between the two groups (P = 0.39).

CONCLUSIONS

The long-term oncologic outcome of laparoscopic resection of primary gastric GISTs is comparable to that of open procedure, but laparoscopic procedure has the advantage of minimal invasion and is superior in postoperative recovery.

Prognostic Analysis of Duodenal Gastrointestinal Stromal Tumors

AIM

This study aims to analyze factors possibly related to the prognosis of duodenal gastrointestinal stromal tumors (DGISTs).

METHODS

We collected and retrospectively analyzed clinical and pathological data of 62 patients with primary DGISTs. All the patients were hospitalized and received complete surgical resection at Shanghai Ruijin Hospital from September 2003 to April 2015. We followed up the patients to determine survival outcomes. We also analyzed the effect of clinical and pathological factors on disease-free survival (DFS) and overall survival (OS) of the patients.

RESULTS

Kaplan-Meier univariate survival analysis demonstrated that tumor size, mitotic index, Ki-67 index, and pathological risk were correlated with the DFS and OS of the patients (DFS P = 0.039, 0.001, <0.001, and 0.005, resp.; OS P = 0.027, 0.007, <0.001, and 0.012, resp.). Cox multivariate regression analysis revealed that Ki-67 index was an independent prognostic factor affecting DFS and OS (P = 0.007 and 0.028, resp.). Moreover, Kaplan-Meier survival analysis showed that imatinib treatment for patients with recurrence was correlated with prolonged OS (P = 0.002).

CONCLUSION

Prognosis for DGIST treated by R0 resection is favorable. High level of Ki-67 can be an independent risk factor of DGIST prognosis. Adjuvant imatinib therapy for patients with tumor recurrence could probably lead to prolonged survival.

Retrospective analysis of 85 cases of intermediate-risk gastrointestinal stromal tumor

Background & Aims

A significant benefit of imatinib adjuvant therapy for patients with high risk gastrointestinal stromal tumors (GIST) has been confirmed. However, the effect of imatinib adjuvant therapy for intermediate-risk GIST has not been well studied. In this article, we compare differences of recurrence-free survival (RFS) rates between patients with intermediate-risk GIST who accepted imatinib adjuvant therapy and those who did not.

Method

A retrospective study of intermediate-risk GIST was conducted in the First Affiliated Hospital of Zhengzhou University, China. The pathology reports of 112 patients who had been treated by surgery showed intermediate-risk GIST. The treatment and control groups were designed according to the administration of imatinib adjuvant therapy (≥1 year). Survival and recurrence data were collected and RFS of each group was calculated.

Results

Eighty fivepatients with intermediate-risk GIST were followed up. Thirty of them (treatment group) accepted imatinib adjuvant therapy over 1 year. Through comparing the RFS of the two groups, we established that there was no statistically significant difference in RFS rates (P=0.940).

Conclusion

There is no significant benefit for patients with intermediate-risk GIST to accept imatinib adjuvant treatment.

The Effect of Marital Status on Survival of Patients with Gastrointestinal Stromal Tumors: A SEER Database Analysis

Background

Marital status has been reported to be a prognostic factor in multiple malignancies. However, its prognostic value on gastrointestinal stromal tumors (GISTs) have not yet been determined. The objective of the present analysis was to assess the effects of marital status on survival in patients with GISTs.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was used to analyze 6195 patients who were diagnosed with GISTs from 2001 to 2014. We also use Kaplan-Meier analysis and Cox regression to analyze the impact of marital status on cancer-specific survival (CSS).

Results

Patients in the married group had more frequency in white people, more high/moderate grade tumors, and were more likely to receive surgery. Widowed patients had a higher proportion of women, a greater proportion of older patients (>60 years), and more common site of the stomach. Multivariate analysis demonstrated that marital status was an independent prognostic factor for GISTs (P < 0.001). Married patients had better CSS than unmarried patients (P < 0.001). Subgroup analysis suggested that widowed patients had the lowest CSS compared with all other patients.

Conclusions

Marital status is a prognostic factor for survival in patients with GISTs, and widowed patients are at greater risk of cancer-specific mortality.

Long-term Results of Adjuvant Imatinib Treatment for Localized Gastrointestinal Stromal Tumors after Surgery

Objective:

Despite the development of two significant classifications for recurrence risk evaluation among patients engaged with gastrointestinal stromal tumor and corresponding treatment criteria, recurrence happens in a number of the patients who were once classified as ineligible for treatment and hence removed from treatment program. As such, the aim of the present study is to increase the number of patients recognized as eligible for treatment, so as to further reduce recurrence rate of this disease.

Materials and Methods:

A total of 26 patients from Ilam, Kermanshah, Lorestan, Kurdistan, and some parts of Hamedan, entered this study from 2006 until 2016. The western provinces included have similar socioeconomical conditions. Inclusion criteria were operable tumors confirmed radiologically with a gross size larger than 3 centimeters regardless of the mitosis rate in microscopic power fields, tumor location, or presence of peritoneal involvement during the surgery. Imatinib capsules were administered daily at 400 mg for 3 years. The patients were followed up every 3 months by radiology, ultrasonography, biochemical assessment, and clinical examination.

Results and Conclusions:

The overall survival after 10-years follow up was 100%, while 5-year survival without relapse was 95%. Mean overall survival was 106 months, and only one patient who had limited peritoneal involvement experienced relapse and he is still alive after 2 years. The drug was well tolerated and no significant side effects were observed.

Systematic review of current prognostication systems for primary gastrointestinal stromal tumors

BACKGROUND

The advent of tyrosine kinase inhibitors as adjuvant therapy has revolutionized the management of GIST and emphasized the need for accurate prognostication systems. Numerous prognostication systems have been proposed for GIST but at present it remains unknown which system is superior. The present systematic review aims to summarize current prognostication systems for primary treatment-naive GIST.

METHODS

A literature review of the Pubmed and Embase databases was performed to identify all published articles in English, from the 1st January 2002 to 28th Feb 2017, reporting on clinical prognostication systems of GIST.

RESULTS

Twenty-three articles on GIST prognostication systems were included. These systems were classified as categorical systems, which stratify patients into risk groups, or continuous systems, which provide an individualized form of risk assessment. There were 16 categorical systems in total. There were 4 modifications of the National Institute of Health (NIH) system, 2 modifications of Armed Forces Institute of Pathology (AFIP) criteria and 3 modifications of Joensuu (modified NIH) criteria. Of the 7 continuous systems, there were 3 prognostic nomograms, 3 mathematical models and 1 prognostic heat/contour maps. Tumor size, location and mitotic count remain the main variables used in these systems.

CONCLUSION

Numerous prognostication systems have been proposed for the risk stratification of GISTs. The most widely used systems today are the NIH, Joensuu modified NIH, AFIP and the Memorial Sloan Kettering Cancer Center nomogram. More validation and comparison studies are required to determine the optimal prognostication system for GIST.

Prognostic role of the primary tumour site in patients with operable small intestine and gastrointestinal stromal tumours: a large population-based analysis

The postoperative recurrence risk of gastrointestinal stromal tumour (GIST) should be estimated when considering adjuvant systemic therapy. Previous studies in the literature have suggested that small intestinal GISTs are more aggressive than gastric GISTs. We assessed the prognostic role of the primary tumour site in patients with operable GIST to compare the outcomes of gastric and small intestinal GISTs over a decade of treatment. The Surveillance, Epidemiology, and End Results (SEER) database was queried for cases of gastric and small intestinal GISTs between 2004 and 2014 using the GIST-specific histology code (ICD-O-3 code 8936), and only patients with tissues sampled by surgical resection were selected for this study. Cancer-specific survival (CSS) and overall survival (OS) were compared between small intestinal and gastric GISTs using Cox regression analyses. GISTs were located in the stomach (n = 2594, 65%), duodenum (n = 228, 6%), and jejunum/ileum (n = 1176, 29%). The OS and CSS of patients with GISTs in the duodenum and jejunum/ileum were similar to those of patients with gastric GISTs in Cox regression analyses, except for the CSS of patients with tumour sizes 2.1-5 cm in diameter and ≤ 5 mitoses per 50 HPFs (HR 1.657; 95% CI 1.062-2.587, p = 0.026). Tumours sizes 2.1–5 cm in diameter and > 5 mitoses per 50 HPFs (HR 4.627; 95% CI 1.035-20.67, p = 0.045) in jejunal/ileal GIST locations had significantly worse CSS than did those in gastric GIST locations. In this large nationwide study, the primary tumour site was not an independent prognostic factor in patients with operable small intestinal and gastric GISTs.

Two staging systems for gastrointestinal stromal tumors in the stomach: which is better?

Background

The prognosis of a gastrointestinal stromal tumor (GIST) is influenced by its anatomic site; however, few studies on the prognosis of gastric GISTs have been reported. The aims of this study were to evaluate long-term prognoses of patients who underwent surgical resection for gastric GISTs and to compare the clinical efficacy of two staging systems: the National Institutes of Health (NIH) consensus criteria and the 7th Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) tumor-node-metastasis (TNM) staging system.

Methods

We conducted a retrospective observational study of 145 patients who underwent surgical resection for gastric GISTs between February 2001 and June 2012 at Pusan National University Hospital (Busan, Korea). Recurrence and 5-year recurrence-free survival (RFS) rates were analyzed.

Results

During a median follow-up period of 44 months (range, 6–144 months), 11 recurrent lesions were detected in 9 patients (6.4%). On multivariate analysis, tumor size (>5 cm), mitotic count (>5/50 high-power fields), and epithelioid and mixed pathological type were significantly associated with recurrence. The overall 5-year RFS rate was 93.4%. Although no statistically significant differences were detected (C-statistic difference P = 0.886), all metrics showed lower values for the UICC/AJCC TNM staging system than for the NIH consensus criteria, suggesting that the UICC/AJCC TNM staging system may be a better model.

Conclusions

The 5-year RFS rate in patients who underwent curative resection for gastric GISTs was excellent. The UICC/AJCC TNM staging system may be more useful than the NIH consensus criteria for risk categorization of patients with gastric GISTs.

Adjuvant imatinib for patients with high-risk gastrointestinal stromal tumors: a retrospective cohort study

The duration of adjuvant imatinib for high-risk patients with gastrointestinal stromal tumors (GISTs) is still controversial. Therefore, we retrospectively analyzed the data of high-risk patients with GISTs to investigate the appropriate duration. All 185 patients were divided into 4 groups: <1 year (Group A), 1–2 years (Group B), 2–3 years (Group C) and >3 years (Group D). The mean recurrence-free survival (RFS) in Groups A, B, and C were 44.3, 62.1, and 86.8 months, respectively (P < 0.001); the mean overall survival (OS) in Groups A, B and C was 75.2, 88.1, and 94.7 months, respectively (P = 0.009). The 5-year RFS in Groups A, B, C, and D was 15%, 26%, 83%, and 100%, respectively (P < 0.001); and the 5-year OS was 64%, 88%, 88%, and 100%, respectively (P < 0.001). The greatest impact on unfavorable outcomes was the tumor mitotic rate (HR, 2.01, 95% CI, 1.38–2.94; P < 0.001). Duration of adjuvant imatinib was the only favorable factor (HR, −0.95, 95% CI, 0.93–0.97; P < 0.001). For high-risk patients with high tumor size or mitotic rate, or non-gastric GISTs, we recommend that more than 3 years of adjuvant imatinib is feasible.

Characterization of malignant gastrointestinal stromal tumors-a single center experience

Background

The recurrence rate, related to the unpredictable behavior of gastrointestinal stromal tumors (GISTs), continues to be a major topic of investigation, since no actual risk evaluation scales have proven to be exceedingly effective in predicting prognosis. We therefore focus in this study on investigating the predictive variables of disease recurrence.

Methods

Between September 2004 and January 2011, 34 patients, 18 males and 16 females with a median age of 62 (range, 27-87) years, underwent operations for primary, localized and advanced GISTs. Immunohistochemical profile, KIT and the platelet-derived growth factor receptor-alpha (PDGFR-α) gene mutations, tumor size, tumor site, mitotic index, synchronous tumors, adjuvant therapy, symptoms and gender were considered and analyzed as predictive variables. The receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off value for tumor dimension to predict recurrence.

Results

The median follow-up (FU) was 20 months (range, 6-86 months). A first-line adjuvant therapy was performed in nine patients. Disease relapse occurred in five cases. The tumor size and the mitotic index were the strongest predictive factors (P<0.001). The optimal maximum value for the tumor size was 7 cm [area under the curve (AUC) =0.955].

Conclusions

In light of the most recent evidence, a tumor size of 7 cm should be considered the threshold value for malignancy, and smaller GISTs with low mitotic counts as tumors with a low-grade risk.

Pancreatic Gastrointestinal Stromal Tumor: Clinicopathologic Features and Prognosis

GOALS

The present study aimed to investigate the clinicopathologic features and prognosis of pancreatic gastrointestinal stromal tumor (GIST).

BACKGROUND

Reports on clinicopathologic features and prognosis of pancreatic GIST are limited due to the extremely rare incidence.

STUDY

One case of pancreatic GIST from our center and 44 cases reported in MEDLINE were enrolled in this study. Clinicopathologic features and prognosis of pancreatic GISTs were analyzed and compared with 297 gastric GISTs from our center.

RESULTS

The most common location was head of pancreas (38.5%). The majority of pancreatic GISTs exceeded 5 cm (74.4%), displayed cystic or mixed imaging features (56.4%), and were high risk (85.7%). The 5-year disease-free survival (DFS) and disease-specific survival rates were 66.1% and 95.8%, respectively. Mitotic index was the only risk factor for DFS of pancreatic GISTs. The distribution of tumor size, histologic type and National Institutes of Health risk category were significantly different between pancreatic and gastric GISTs. The 5-year DFS rate of pancreatic GISTs was significantly lower than that of gastric GISTs. Multivariate analysis showed that location was an independent prognostic factor for DFS between pancreatic and gastric GISTs.

CONCLUSIONS

The most common location was head of pancreas. The majority of pancreatic GISTs were large and highly malignant. Pancreatic GISTs differed significantly from gastric GISTs in respect to clinicopathologic features. The DFS of pancreatic GISTs was worse than that of gastric GISTs.

Laparoscopic resection of gastrointestinal stromal tumors: Does laparoscopic surgery provide an adequate oncologic resection?

Gastrointestinal stromal tumors (GISTs) are rare tumors of the GI tract. Surgical resection remains the mainstay of non-metastatic disease. However, the ability to provide an adequate oncologic resection using laparoscopic surgery is still an area of debate. This is a thorough review of the current literature, looking particularly at the use of laparoscopic surgery for larger GISTs and the long-term oncologic outcomes compared to the results of open surgery. Laparoscopic resections provide an adequate oncologic result for GISTs of all sizes, including those greater than 5 cm in size.

Characterizing gastrointestinal stromal tumors and evaluating neoadjuvant imatinib by sequencing of endoscopic ultrasound-biopsies

AIM

To evaluate endoscopic ultrasound (EUS)-guided biopsies for the pretreatment characterization of gastrointestinal stromal tumors (GIST) to personalize the management of patients.

METHODS

All patients with lesions suspected to be GIST who were referred for EUS-sampling at a tertiary Swedish center were eligible for inclusion 2006-2015. During the observational study phase (2006-2011), routine fine-needle-aspiration (EUS-FNA) was performed. In 2012-2015, we converted to an interventional, randomized protocol with dual sampling EUS-FNA and fine-needle-biopsy-sampling (EUS-FNB) for all lesions. c-KIT- and DOG-1-immunostaining was attempted in all samples and a manual count of the Ki-67-index was performed. FNB-sampled tissue and the resected specimens were subjected to Sanger sequencing of the KIT and platelet-derived growth factor alpha (PDGFRA) genes.

RESULTS

In all, 64 unique patients with GIST were included, and of these, 38 were subjected to pretreatment dual sampling. EUS-FNB had a higher diagnostic sensitivity when compared head-to-head with EUS-FNA (98% vs 58%, P < 0.001) and was more adequate for Ki-67-indexing (Ki-67_EUS) (92% vs 40%, P < 0.001). Sequencing of EUS-biopsies was successful in 43/44 (98%) patients, and the mutation profiles (KIT-mutation 73%, PDGFRA-mutation 18%, wild-type 7%) were fully congruent with those detected in the corresponding resected specimens. In imatinib-naïve patients, the Ki-67_EUS was comparable with the Ki-67-index in the corresponding surgical specimens (Ki-67_SURG) (2.7% vs 2.9%, P = 0.68). In patients treated with neoadjuvant imatinib who also carried mutations indicating sensitivity, the Ki-67_EUS was higher than the Ki-67_SURG (2.5% vs 0.2%, P = 0.005), with a significant reduction in the Ki-67-index of -91.5% (95%CI: -82.4 to -96.0, P = 0.005).

CONCLUSION

EUS-guided biopsy sampling is accurate for the pretreatment diagnosis and characterization of GISTs and allows the prediction and evaluation of tumor response to neoadjuvant imatinib therapy.

[Clinical and morphological characteristics of gastrointestinal stromal tumors]

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Despite this, GISTS comprise about 2% in the structure of digestive tract cancers. They are usually localized in the stomach; however, they can be found in the small intestine and more rarely in the colon and esophagus. Although approximately 70% of the GISTs consist predominantly of spindle cells; the epithelioid cell tumors represent 20% of cases; there are also mixed variants. This variability in the morphological structure of GISTs complicates their diagnosis.

Effect of KIT and PDGFRA Mutations on Survival in Patients With Gastrointestinal Stromal Tumors Treated With Adjuvant Imatinib: An Exploratory Analysis of a Randomized Clinical Trial

Importance

Little is known about whether the duration of adjuvant imatinib influences the prognostic significance of KIT proto-oncogene receptor tyrosine kinase (KIT) and platelet-derived growth factor receptor α (PDGFRA) mutations.

Objective

To investigate the effect of KIT and PDGFRA mutations on recurrence-free survival (RFS) in patients with gastrointestinal stromal tumors (GISTs) treated with surgery and adjuvant imatinib.

Design, Setting, and Participants

This exploratory study is based on the Scandinavian Sarcoma Group VIII/Arbeitsgemeinschaft Internistische Onkologie (SSGXVIII/AIO) multicenter clinical trial. Between February 4, 2004, and September 29, 2008, 400 patients who had undergone surgery for GISTs with a high risk of recurrence were randomized to receive adjuvant imatinib for 1 or 3 years. Of the 397 patients who provided consent, 341 (85.9%) had centrally confirmed, localized GISTs with mutation analysis for KIT and PDGFRA performed centrally using conventional sequencing. During a median follow-up of 88 months (completed December 31, 2013), 142 patients had GIST recurrence. Data of the evaluable population were analyzed February 4, 2004, through December 31, 2013.

Main Outcomes and Measures

The main outcome was RFS. Mutations were grouped by the gene and exon. KIT exon 11 mutations were further grouped as deletion or insertion-deletion mutations, substitution mutations, insertion or duplication mutations, and mutations that involved codons 557 and/or 558.

Results

Of the 341 patients (175 men and 166 women; median age at study entry, 62 years) in the 1-year group and 60 years in the 3-year group), 274 (80.4%) had GISTs with a KIT mutation, 43 (12.6%) had GISTs that harbored a PDGFRA mutation, and 24 (7.0%) had GISTs that were wild type for these genes. PDGFRA mutations and KIT exon 11 insertion or duplication mutations were associated with favorable RFS, whereas KIT exon 9 mutations were associated with unfavorable outcome. Patients with KIT exon 11 deletion or insertion-deletion mutation had better RFS when allocated to the 3-year group compared with the 1-year group (5-year RFS, 71.0% vs 41.3%; P < .001), whereas no significant benefit from the 3-year treatment was found in the other mutational subgroups examined. KIT exon 11 deletion mutations, deletions that involved codons 557 and/or 558, and deletions that led to pTrp557_Lys558del were associated with poor RFS in the 1-year group but not in the 3-year group. Similarly, in the subset with KIT exon 11 deletion mutations, higher-than-the-median mitotic counts were associated with unfavorable RFS in the 1-year group but not in the 3-year group.

Conclusions and Relevance

Patients with KIT exon 11 deletion mutations benefit most from the longer duration of adjuvant imatinib. The duration of adjuvant imatinib modifies the risk of GIST recurrence associated with some KIT mutations, including deletions that affect exon 11 codons 557 and/or 558.

Trial Registration

clinicaltrials.gov Identifier: NCT00116935.

Robotic Versus Laparoscopic Gastric Resection for Primary Gastrointestinal Stromal Tumors >5 cm: A Size-Matched and Location-Matched Comparison

This study compared robotic (RR) and laparoscopic resection (LR) for primary gastrointestinal stromal tumors (GISTs) of the stomach >5 cm. Twelve consecutive patients who underwent RR from 2012 to 2015 were matched for tumor size and location with 24 patients who underwent LR from 2000 to 2012. The median tumor size was 7.1 cm (range, 5.5 to 11.5). GISTs were resected by wedge resection (91.7%) or distal gastrectomy. The median RR operative time was longer than that of LR (162.5 vs. 130 min, respectively; P=0.004). Only 1 LR patient required conversion. The time to flatus and hospital stay were similar between groups. Overall, 3 patients developed minor postoperative complications that were medically treated. Mortality was nil. All resections were R0. No difference was observed in the incidence of recurrence. RR was significantly more expensive (+21.6%) than LR. RR appears to be safe and feasible for GISTs>5 cm, but is associated with longer operative times and greater costs.

Case report of diffusely metastatic rectal GIST

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Rectal gastrointestinal tumors (GISTs) are rare mesenchymal tumors.

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Rectal GISTs are extremely rare and account for approximately 2% of all GIST tumors.

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Majority of GISTs have a benign course.

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Treatment with imatinib mesylate should be arranged as soon as possible.

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The most common cause of death after resection of a rectal GIST is distant metastasis.

This is a case report of an aggressive, diffusely disseminated Stage IV rectal gastrointestinal stromal tumor (GIST) in a 57-year-old male that presented for symptoms of malaise, constipation, and twenty pound weight loss in 2 months. Upon rectal examination, a hard 4 centimeter submucosal mass was found at the 9–12 o’clock position. Liver and lung metastases were visualized on computerized tomography (CT) of the chest, abdomen, and pelvis on metastatic work-up. He was deemed a poor surgical candidate due to diffuse metastatic disease and referred for palliative chemotherapy. The patient had suffered a perforation of his rectal wall two weeks after his initial presentation and passed away shortly thereafter. He never received palliative chemotherapy. We present a case report as a unique case of an extremely aggressive and quickly fatal GIST tumor.

Phase II study of neoadjuvant imatinib in large gastrointestinal stromal tumours of the stomach

BACKGROUND

Gastrointestinal stromal tumours (GISTs) with high-risk features have poor prognosis even if adjuvant treatment is given. Neoadjuvant imatinib may increase the cure rate by shrinking large GISTs and preserve organ function.

METHODS

We conducted an Asian multinational phase II study for patients with gastric GISTs ≥10 cm. Patients received neoadjuvant imatinib (400 mg/day) for 6-9 months. The primary end point was R0 resection rate.

RESULTS

A total of 56 patients were enroled in this study. In the full analysis set of 53 patients, neoadjuvant imatinib for ≥6 months was completed in 46 patients. Grade 3-4 neutropenia and rash occurred in 8% and 9%, respectively, but there were no treatment-related deaths. The response rate by RECIST was 62% (95% CI, 48-75%). The R0 resection rate was 91% (48/53) (95% CI, 79-97%). Preservation of at least half of the stomach was achieved in 42 of 48 patients with R0 resection. At the median follow-up time of 32 months, 2-year overall and progression-free survival rates were 98% and 89%, respectively.

CONCLUSIONS

Neoadjuvant imatinib treatment for 6-9 months is a promising treatment for large gastric GISTs, allowing a high R0 resection rate with acceptable toxicity.

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.

Long-term outcomes of endoscopic resection of gastric GISTs

OBJECTIVE

Although the endoscopic treatment of gastric stromal tumors is a recently accepted therapy, the long-term outcomes of this approach remain unknown. The aims of this study were to assess the long-term effectiveness and safety of endoscopic resection for gastric GISTs.

METHODS

A total of 60 consecutive patients undergoing endoscopic resection of gastric GISTs were enrolled in a retrospective single-center study. Clinical data, perioperative complications, histopathologic characteristics of the tumors, and long-term outcomes were recorded.

RESULTS

Sixty patients successfully underwent complete resection of lesions, including 25 cases of endoscopic submucosal dissection (ESD) and 35 cases of endoscopic full-thickness resection (EFTR), with an average tumor size of 1.76 ± 1.55 cm (range 0.5-7.6 cm). The average operation time was 43.97 ± 26.95 min (range 11.7-138.9 min). Two cases were observed with an intraoperative hemorrhage of 200 mL, which were successfully managed by hemostatic forceps. Perforations of 2-11 mm of ESD occurred in four cases (4/25) and were well closed with endoclips, with no conversions to surgical operation. Mucosal laceration of esophagus occurred in 1 case, when a large tumor was removed. The average length of hospitalization was 6.50 ± 3.06 days (range 3-21 days). Out of a total of 60 patients, 44 (73.3%) were at very low risk, 10 (16.7%) were at low risk, 5 (8.3%) were at intermediate risk, and 1 (1.7%) was at high risk. All patients were followed-up for 36.15 ± 12.92 months (range 14-73 months). Primary tumor recurrence occurred in 1 patient who underwent a second operation after 32 months, and no other cases were observed to have either tumor recurrence or metastasis.

CONCLUSIONS

For long-term outcomes, endoscopic resection of ESD or EFTR is a safe and effective approach for removing gastric stromal tumors (<5 cm), and it can be a resection technique for them with no metastasis.

LAPAROSCOPIC RESECTION OF GASTROINTESTINAL STROMAL TUMORS (GIST)

BACKGROUND

Gastrointestinal mesenchymal or stromal tumors (GIST) are lesions originated on digestive tract walls, which are treated by surgical resection. Several laparoscopic techniques, from gastrectomies to segmental resections, have been used successfully.

AIM

Describe a single center experience on laparoscopic GIST resection.

METHOD

Charts of 15 operated patients were retrospectively reviewed. Thirteen had gastric lesions, of which ten were sub epithelial, ranging from 2-8 cm; and three were pure exofitic growing lesions. The remaining two patients had small bowel lesions. Surgical laparoscopic treatment consisted of two distal gastrectomies, 11 wedge gastric resections and two segmental enterectomies. Mechanical suture was used in the majority of patients except on six, which underwent resection and closure using manual absorbable sutures. There were no conversions to open technique.

RESULTS

Mean operative time was 1h 29 min±92 (40-420 min). Average lenght of hospital stay was three days (2-6 days). There were no leaks, postoperative bleeding or need for reintervention. Mean postoperative follow-up was 38±17 months (6-60 months). Three patients underwent adjuvant Imatinib treatment, one for recurrence five months postoperatively and two for tumors with moderate risk for recurrence .

CONCLUSION

Laparoscopic GIST resection, not only for small lesions but also for tumors above 5 cm, is safe and acceptable technique.

Skeletal Muscle Metastasis of a GIST: A Case Report and Review of the Literature

Gastrointestinal stromal tumors (GISTs) are the most common malignant mesenchymal tumors of the gastrointestinal tract. The most common sites of metastasis are the liver and the peritoneum, whereas metastasis to soft tissue is rare. The authors present the case of a 78-year-old male with a soft tissue metastasis of a GIST and the current literature is reviewed.

Contrast-enhanced (endoscopic) ultrasound and endoscopic ultrasound elastography in gastrointestinal stromal tumors

Background and Objectives:

Gastrointestinal stromal tumors (GISTs) represent the largest group of subepithelial tumors (SET) of the upper gastrointestinal (GI) tract. They may show malignant behavior, in contrast to other SET. Endoscopic ultrasound (EUS) is frequently used to characterize SET. With the introduction of contrast-enhanced ultrasound (CEUS) into EUS (CE-EUS), distinct enhancement patterns can be detected. In the presented study, the characteristic features of CE-EUS in GIST are analyzed and compared with those of other SET.

Materials and Methods:

Consecutive patients from four centers with SET of the upper and middle GI tract were included and received endoscopic or transcutaneous CEUS. The results were compared with EUS-guided tissue acquisition, forceps biopsy, or surgical resection.

Results:

Forty-two out of 62 (68%) patients had SET of the stomach, 17/62 (27%) of the small intestine, 2/62 (3%) of the esophagus, and 1/62 (2%) extraintestinal. Eighty-one percent underwent surgery. Leiomyoma was found in 5/62 (8%) and GIST in 57/62 patients (92%). Thirty-nine out of 57 (68%) patients had GIST lesions in the stomach, 17/57 (30%) had GIST of the small intestine, and 1/57 (2%) patients had extraintestinal GISTs. GIST size was 62.6 ± 42.1 (16–200) mm. Hyperenhancement had a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 98%, 100%, 100%, 93%, and 98% for the diagnosis of GIST. Fifty out of 57 patients with GIST (88%) showed avascular areas in the center of the lesions.

Conclusion:

CE-EUS and CEUS show hyperenhancement and avascular areas in a high percentage of GIST but not in leiomyoma. Thus, GIST and leiomyoma can be discriminated accurately.

Surgical Management of Wild-Type Gastrointestinal Stromal Tumors: A Report From the National Institutes of Health Pediatric and Wildtype GIST Clinic

Purpose Wild-type gastrointestinal stromal tumors (WT-GISTs) that lack KIT or PDGFRA mutations represent a unique subtype of GIST that predominantly affects children. We sought to determine the effect on event-free survival (EFS) of staging variables, extent of resection, and repeat resection of tumors. Methods In 2008, a WT-GIST clinic was established at the National Cancer Institute, allowing the development of a large clinical database. We included participants who underwent resection of WT-GIST. Associations with EFS (ie, freedom from disease progression or recurrence) were evaluated using the Kaplan-Meier method and Cox proportional hazards modeling. Results Among 76 participants with WT-GISTs, the median follow-up was 4.1 years. Overall EFS (± SE) was 72.6 ± 5.4% at 1 year, 57.6 ± 6.2% at 2 years, 23.7 ± 6.0% at 5 years, and 16.3 ± 5.5% at 10 years postoperatively. Hazard of disease progression or recurrence was significantly increased for patients with metastatic disease (adjusted hazard ratio [AHR], 2.3; 95% CI, 1.0 to 5.1; P = .04) and > 5 mitoses per 50 high-power fields (AHR, 2.5; 95% CI, 1.1 to 6.0; P = .03), whereas there was no significant effect of negative microscopic resection margins (AHR, 0.9; 95% CI, 0.4 to 2.2; P = 0.86). There was no association between type of gastric resection (ie, anatomic v partial/wedge) and EFS ( P = .67). Repeated resection after the initial resection was significantly associated with decreasing postoperative EFS ( P < .01). Five patients (6%) died after initial enrollment in 2008. Conclusion WT-GIST is an indolent disease, and most patients survive with disease progression. We found no improvement in EFS with more extensive or serial resections. Disease progression or recurrence may be more closely related to tumor biology than surgical management. These data suggest that resections for WT-GISTs be restricted to the initial procedure and that subsequent resections be performed only to address symptoms such as obstruction or bleeding.

Gastric and small intestine gastrointestinal stromal tumors: Do outcomes differ?

BACKGROUND AND OBJECTIVES

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Previous literature has suggested that small intestine GISTs are more aggressive than gastric GISTs. Our primary objective was to compare the outcomes of gastric and small intestine GISTs in the decade after approval of imatinib for treatment.

METHODS

The SEER database was queried for cases of gastric and small intestine GIST between the years 2002 and 2012, using the ICD-O-3 histology code 8936. Survival analysis was performed using generalized gamma models for time to cause-specific mortality (CSM).

RESULTS

CSM was 14.0% for the 3,759 gastric GIST patients and 14.3% for the 1,848 small intestine GIST patients. Five-year survival was 82.2% and 83.3% for gastric and small intestine patients, respectively. The number of diagnosed cases of GIST increased over the course of this study, especially for tumors <5 cm in size and in patients over age 50 years.

CONCLUSIONS

In this large nation-wide study, we found that patients with gastric and small intestine GISTs had similar outcomes, in contrast to previous reports. The diagnosis of GIST has significantly increased in the last decade, which may reflect the increased recognition of this entity and frequent use of imaging. J. Surg. Oncol. 2017;115:351-357. © 2016 Wiley Periodicals, Inc.

Rectal GIST-Outcomes and viewpoint from a tertiary cancer center

INTRODUCTION

There is scarce data relating to methods to improve sphincter preservation in rectal gastrointestinal stromal tumor (GIST). Increasing the duration of neoadjuvant (NA) imatinib resulting in improved sphincter preservation rate has not been established. This retrospective analysis looks at the rates of sphincter preservation in rectal GIST with NA imatinib and effect of duration of NA imatinib on the same to find out optimum duration of NA with respect to sphincter preservation in rectal GIST patients.

METHODS

Twenty-three cases of GIST of lower third of rectum were treated at our centre from 2005 till 2015. NA imatinib was used in a dose of 400 mg. Response evaluation was done every 3 months with a pelvic magnetic resonance imaging. Surgical management was determined by a team of experienced gastrointestinal oncosurgeons.

RESULTS

Five patients underwent upfront surgery which included local resection in four patients and abdominoperineal resection in one patient. NA imatinib was used in 69.5 % (16/23) patients. Median duration of NA imatinib was 15 months (3-84 months). Amongst who underwent a sphincter-salvage surgery median duration of NA imatinib was 13 months whereas 18 months in patients who required a sphincter-sacrificing surgery (p = 0.683). The radiologic response included partial response in 75 % (12/16) patients, stable disease in 18.7 % (3/16) and one with progressive disease. Definitive surgical resection was possible in 13 patients (81.3 %) after NA imatinib. Median progression-free survival (PFS) was 120 months in the whole cohort whereas median overall survival (OS) was not reached. Four-year estimated PFS and OS was 81 % and 100 %, respectively. Median disease-free survival in upfront surgery group vs. neoadjuvant imatinib group was 70 vs. 120 months, respectively (p = 0.039).

CONCLUSION

Neoadjuvant imatinib appears to be a useful option in improving chances of sphincter preservation without adversely affecting the outcome. Use of neoadjuvant imatinib leads to improvement in progression-free survival in patients with GIST of lower third of the rectum.

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.

Clinicopathological feature and prognosis of primary hepatic gastrointestinal stromal tumor

Compared to gastric gastrointestinal stromal tumor (GIST), hepatic GIST is very rare in clinic. Reports on clinicopathological feature and prognosis of this rare disease are limited in literature. The purpose of this study was, therefore, to summarize clinical and pathological features as well as prognosis of the primary hepatic GIST. One case of primary hepatic GIST from our center and 22 cases reported in MEDLINE or China National Knowledge Infrastructure (CNKI) were enrolled into this study. Clinicopathological features as well as survival data of hepatic GIST were analyzed and compared with 297 gastric GISTs and 59 small intestinal GISTs from our center. Majority of the 22 cases (95.7%) of hepatic GIST was larger than 5 cm in size, and 75.0% of the tumors were over 5/50 HPF in mitotic index. Most of the hepatic GISTs (85.7%) displayed spindle cell shape in morphology. All of the hepatic GIST (100%) enrolled in this study were classified as high-risk category by the National Institute of Health (NIH) risk classification. The 5-year median disease-free survival (DFS) time was 24.0 months and 5-year disease-specific survival (DSS) rate was 33.3%, respectively. Distribution of clinicopathological features was significantly different among hepatic, gastric, and small intestinal GIST. The DFS and DSS of hepatic GIST were significantly lower than those of the other two groups. Majority of the hepatic GIST is large in size and highly malignant. Prognosis of the primary hepatic GIST is worse than that of gastric GIST and small intestinal GIST.

Blood-Based Biomarkers Are Associated with Disease Recurrence and Survival in Gastrointestinal Stroma Tumor Patients after Surgical Resection

Background

Inflammatory blood count biomarkers may improve recurrence risk stratification and inform long-term prognosis of cancer patients. Here, we quantify the prognostic impact of blood-based biomarkers on recurrence risk and long-term survival in a large cohort of gastrointestinal stroma tumor (GIST) patients after curative surgery.

Methods

One-hundred-forty-nine consecutive GIST patients were followed-up for a median period of 4.8 years. Local recurrence, distant metastasis, and death occurred in 9, 21, and 31 patients, respectively. Time-to-event and competing risk analysis were applied to study the association between haemoglobin (Hb) level, white blood cell count (WBC), neutrophil/lymphocyte ratio (NLR), derived NLR (dNLR), lymphocyte/monocyte ratio (LMR), and platelet/lymphocyte ratio (PLR) with risk of local or distant recurrence (RR), recurrence free survival (RFS), and overall survival (OS).

Results

A low Hb (p = 0.029), and elevations in the parameters WBC (p = 0.004), NLR (p = 0.015) and dNLR (p = 0.037) were associated with a poor OS in GIST patients in multivariate analysis. Moreover, a low Hb (p = 0.049) and an elevated WBC (p = 0.001), NLR (p = 0.007), dNLR (p = 0.043) and PLR (p = 0.024) were independently associated with decreased RFS after adjusting for Miettinen score. However, only an increase of dNLR/NLR showed a significant association to higher RR (p = 0.048). Inclusion of NLR or PLR to Miettinen risk score did not reasonably improve the clinical risk prediction of 2-year RFS.

Conclusion

Low Hb, elevated WBC, elevated dNLR, and elevated PLR are independent prognostic factors for a worse clinical outcome in GIST patients after curative resection.

Clinicopathological features and prognosis of colonic gastrointestinal stromal tumors: evaluation of a pooled case series

Background

Due to the extremely rare incidence, data about colonic GISTs are limited. Therefore, aim of the present study was to explore clinicopathological characteristics and prognosis of colonic GISTs.

Patients and Methods

Colonic GISTs cases were obtained from our center and from case report and clinical studies extracted from MEDLINE. Clinicopathological features and survivals were analyzed.

Results

There were 79 colonic GISTs patients with a female predominance. The median age was 66 years (range 0.17-84). The median tumor size was 5.8 cm (range 0.5-29). The most common location was sigmoid colon (45.8%), followed by transverse colon (19.5%). The majority of colonic GISTs were high risk (70.8%). Mitotic index was correlated with gender (P = 0.002) and tumor size (P = 0.005), and tumor location was correlated with age (P = 0.017). The five year DFS and DSS were 57.4% and 61.6%, respectively. Mitotic index and NIH risk classification were associated with prognosis of colonic GISTs. However, mitotic index was the only independent risk factor. The distribution of tumor size and NIH risk classification were significantly different between colonic and gastric GISTs (both P = 0.000). The DFS and DSS of colonic GISTs were significantly lower than that of gastric GISTs (P = 0.012 and P = 0.002, respectively).

Conclusions

The most common location for colonic GISTs was sigmoid colon. Most tumors were high risk. Mitotic index was the only independent risk factor for prognosis of colonic GISTs. Colonic GISTs differ significantly from gastric GISTs in respect to clinicopathological features. The prognosis of colonic GISTs was worse than that of gastric GISTs.

A meta-analysis of prognostic value of KIT mutation status in gastrointestinal stromal tumors

Numerous types of KIT mutations have been reported in gastrointestinal stromal tumors (GISTs); however, controversy still exists regarding their clinicopathological significance. In this study, we reviewed the publicly available literature to assess the data by a meta-analysis to characterize KIT mutations and different types of KIT mutations in prognostic prediction in patients with GISTs. Twenty-eight studies that included 4,449 patients were identified and analyzed. We found that KIT mutation status was closely correlated with size of tumors and different mitosis indexes, but not with tumor location. KIT mutation was also observed to be significantly correlated with tumor recurrence, metastasis, as well as the overall survival of patients. Interestingly, there was higher risk of progression in KIT exon 9-mutated patients than in exon 11-mutated patients. Five-year relapse-free survival (RFS) rate was significantly higher in KIT exon 11-deleted patients than in those with other types of KIT exon 11 mutations. In addition, RFS for 5 years was significantly worse in patients bearing KIT codon 557–558 deletions than in those bearing other KIT exon 11 deletions. Our results strongly support the hypothesis that KIT mutation status is another evaluable factor for prognosis prediction in GISTs.

Metastatic Liver Disease Associated with Gastrointestinal Stromal Tumors: Controversies in Diagnostic and Therapeutic Approach

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most frequent mesenchymal lesions of the GI tract. They are considered to originate from neoplastic transformation of either the intestinal pacemaker cells of Cajal or the precursor pluripotential stem cells. The genetic basis of GIST growth is an activating mutation of two receptor tyrosine kinases. Recent epidemiologic studies demonstrate that the GIST prevalence is approximately 20/1000000/year. Although GISTs develop in every part of the GI tract, stomach remains the most common localization. About 80 % of the patients experience tumor recurrence or hepatic metastasis after radical resection. GIST liver metastases are usually multiple, large in diameter, and localized in both lobes. In addition, GISTs are usually completely asymptomatic, discovered incidentally. Symptoms are not typical and depend on the location, size, and aggressiveness of the tumor.

DISCUSSION

Diagnostic evaluation is based on imaging techniques, such as computed tomography, magnetic resonance imaging, positron emission tomography, and endoscopic ultrasound. Despite recent research on the therapeutic strategies against GISTs, surgical resection appears the only potentially curative approach. For the advanced metastatic disease, imatinib, a tyrosine kinase inhibitor, has been proposed neoadjuvantly with the surgery performed after the adequate reduction of tumor burden. The aim of this review was to evaluate the results of surgical treatment for metastatic GIST with special reference to the extent of its histological spread and to present the recent literature in order to provide an update on the current concepts of advanced surgical management of this entity.

Evaluation of Gold's nomogram for predicting recurrence-free survival in gastrointestinal stromal tumors in Indian patients

Gold described a nomogram for prediction of recurrence-free survival (RFS) after surgery for gastrointestinal stromal tumors (GIST). This retrospective study was intended to evaluate the utility of this nomogram for predicting a 2-year RFS in our patients. Twenty-eight consecutive eligible patients from January 2009 to January 2013 who underwent R0 resection and had histopathologically proven GIST were included in the study. Nomogram predicted RFS was compared with observed RFS in four groups as in the National Institutes of Health (NIH)-Fletcher classification. Calibration was assessed by plotting the predicted probabilities of RFS against the actual outcome. For validation of the nomogram, the graph obtained should be closer to the 45-degree line. The observed overall 2-year RFS was 85.7 % (24 patients). Four patients had recurrence within 2 years. The observed RFS was 87.5 %, 77.8 %, 90 %, and 100 % in the high, intermediate, low, and very low risk groups, respectively. The nomogram predicted the 2-year RFS was 40 %, 84.8 %, 88.6 %, and 90 % for high, intermediate, low, and very low risk groups, respectively. Thus, the predicted probabilities of the 2-year RFS in intermediate, low, and very low risk groups were similar to the observed outcomes. However, for the high risk group, the observed RFS was better than predicted RFS. This variation in the high risk group may be due to the use of adjuvant imatinib in our study.

Small EUS-suspected gastrointestinal stromal tumors of the stomach: An overview for the current state of management

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors found in the gastrointestinal (GI) tract, with the stomach being the most common site. They represent a distinct group of GI tumors originating from the interstitial cells of Cajal and are characterized by gain-of-function mutations of KIT. KIT oncoprotein serves as both diagnostic and therapeutic targets. Prognosis is related to size, mitotic activity, and site of the tumor. Asymptomatic, small endoscopic ultrasonography (EUS)-suspected GISTs are increasingly encountered with the wide availability of endoscopic/endosonographic examination. The majority of small GISTs are biologically indolent, albeit possibly harboring c-KIT gene mutations. An ongoing controversy exists regarding the management and surveillance policy for small gastric GISTs. A number of reports on the management of GISTs have been published, not confidently addressing the issue of gastric GISTs of small size. This work provides an overview on the current state of management considerations, specifically focusing on small EUS-suspected gastric GISTs, which are increasingly encountered by clinicians.

Combination of PLR, MLR, MWR, and Tumor Size Could Significantly Increase the Prognostic Value for Gastrointestinal Stromal Tumors

Systemic inflammation and immune response were associated with prognosis of tumors. However, data was limited due to the relatively low incidence of gastrointestinal stromal tumors (GISTs). The aim of the present study was to investigate the predictive value of preoperative peripheral blood cells in prognosis of GISTs.From September 2008 to July 2015, a total of 274 GIST patients in our department were enrolled in the present study. Clinicopathological features of GISTs were recorded. The association between preoperative peripheral blood cells and prognosis of GISTs were analyzed.Tumor location, tumor size, mitotic index, intratumoral necrosis, and National Institutes of Health (NIH) risk category were associated with prognosis of GISTs. High neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), neutrophil-to-white blood cell ratio (NWR), monocyte-to-white blood cell ratio (MWR) and low lymphocyte-to-white blood cell ratio (LWR) was associated with poor prognosis of GISTs (76.2% vs 83.7%, P = 0.010. 70.5% vs 98.7%, P = 0.000. 65.7% vs 96.4%, P = 0.004. 78.5% vs 82.5%, P = 0.044. 73.5% vs 97.8%, P = 0.004. 76.6% vs 83.6%, P = 0.012, respectively). However, tumor size was the only independent risk factor for prognosis according to multivariate analysis (P = 0.006). Tumor location, tumor size, mitotic index, and NIH risk category were significantly correlated with the above-mentioned parameters (all P < 0.05). The prognosis of GISTs with tumor size >5 cm, high MLR, high PLR, and high MWR was significantly lower than the remnant patients (P = 0.010).The peripheral blood routine test is convenient, reproducible, and inexpensive. High NLR, MLR, PLR, NWR, MWR, and low LWR were associated with poor prognosis of GISTs. The association between the above parameters and prognosis of GISTs may be attributed to their correlation with tumor size, mitotic index, and NIH risk category. The combination of tumor size, MLR, PLR, and MWR could further increase the predictive value of prognosis of GISTs.

Definition and clinical significance of tumour rupture in gastrointestinal stromal tumours of the small intestine

BACKGROUND

Tumour rupture is a risk factor for recurrence of gastrointestinal stromal tumour (GIST). In this study, patterns of recurrence after potential tumour seeding were investigated, and a new definition of tumour rupture, based on major and minor defects of tumour integrity, is proposed.

METHODS

Patients undergoing surgery for non-metastatic small intestinal GIST from 2000 to 2012 were included in the study. Tumour spillage, tumour fracture or piecemeal resection, bowel perforation at the tumour site, blood-tinged ascites, microscopic tumour infiltration into an adjacent organ, and surgical biopsy were defined as major defects of tumour integrity. Peritoneal tumour penetration, iatrogenic peritoneal laceration and microscopically involved margins were defined as minor defects.

RESULTS

Seventy-two patients were identified. Median follow-up was 58 (range 7-122) months. Radical surgery was performed in 71 patients. A major defect was recorded in 20 patients, and a minor defect in 21. The 5-year recurrence rate was 64, 29 and 31 per cent in patients with major, minor and no defect respectively (P = 0·001). The hazard ratio (HR) for major defect versus no defect was 3·55 (95 per cent c.i. 1·51 to 8·35). Peritoneal recurrence rates for major, minor and no defect were 52, 25 and 19 per cent respectively (P = 0·002), and the HR for major defect versus no defect was 4·98 (1·69 to 14·68). On multivariable analysis, mitotic index, major defect of tumour integrity, tumour size and age were independently associated with risk of recurrence.

CONCLUSION

Recurrence rates were increased after major, but not minor tumour ruptures.

A gastrointestinal stromal tumor at the esophagogastric junction successfully treated by laparoscopic wedge resection with seromuscular layer dissection: a case report

Herein, we report a case of a gastrointestinal stromal tumor (GIST) at the esophagogastric junction (EGJ) that was successfully treated by a laparoscopic wedge resection (LWR) after dissection of the seromuscular layer around the tumor to prevent postoperative deformities and stenosis of the EGJ. Subsequently, the abdominal esophagus was wrapped by the gastric fornix according to Dor's method in order to prevent reflux esophagitis after surgery.A 71-year-old female patient was admitted with a diagnosis of a GIST (23 × 20 × 20 mm) at the EGJ. We performed the abovementioned operation.Gastroduodenal endoscopic examination revealed no deformity or stenosis of the EGJ at 6 months after the operation. The patient has not experienced any reflux symptoms. Tumor recurrence was not noted 26 months after the operation.This procedure is useful in preventing the deformity and stenosis of the EGJ as well as postoperative reflux esophagitis.

The predictive value of preoperative 18F-fluorodeoxyglucose PET for postoperative recurrence in patients with localized primary gastrointestinal stromal tumour

OBJECTIVES

To assess the potential value of preoperative ¹⁸F-FDG PET to predict postoperative recurrence of solitary localized primary gastrointestinal stromal tumour (GIST) after radical resection.

METHODS

A total of 46 patients with primary GIST who received preoperative ¹⁸F-FDG PET and underwent complete resection without neoadjuvant therapy were retrospectively studied. PET findings, including ring-shaped uptake and intense uptake, were compared with Joensuu risk grades using Fisher's exact test. The prognostic value of the preoperative clinico-imaging variables-age ≥60 years, male, ring-shaped uptake, intense uptake, tumour size >5 cm, heterogeneous CT attenuation and lower gastrointestinal origin-and Joensuu high risk for recurrence-free survival was evaluated using log-rank test and multivariate Cox regression analysis.

RESULTS

Ring-shaped uptake and intense uptake were significantly associated with Joensuu high risk. Univariate analysis showed that ring-shaped uptake, intense uptake, size >5 cm and Joensuu high risk were significantly associated with inferior recurrence-free survival. Multivariate analysis showed that ring-shaped uptake (P = 0.004) and Joensuu high risk (P = 0.021) were independent adverse prognostic factors of postoperative recurrence.

CONCLUSIONS

Ring-shaped uptake on preoperative ¹⁸F-FDG PET may be a potential predictor of postoperative tumour recurrence of localized primary GISTs.

KEY POINTS

• Clinical course of resectable solitary localized primary GISTs varies widely. • Ring-shaped uptake is an independent adverse prognostic factor of postoperative recurrence. • Preoperative ¹⁸ F-FDG PET may help predict postoperative recurrence of GISTs.

Relationship between imatinib trough concentration and outcomes in the treatment of advanced gastrointestinal stromal tumours in a real-life setting

BACKGROUND

Imatinib has dramatically improved the prognosis of advanced gastrointestinal stromal tumours (GISTs). Clinical trial data showed that patients with trough imatinib plasma concentrations (Cmin) below 1100 ng/ml (quartile 1) had shorter time to progression, but no threshold has been defined. The main objective of this study was to investigate in advanced GIST whether a Cmin threshold value associated with a longer progression-free survival (PFS) could be specified. This would be the first step leading to therapeutic drug monitoring of imatinib in GIST.

PATIENTS AND METHODS

Advanced GIST patients (n=96) treated with imatinib 400 mg/d (41 stomach, 34 small bowel, and 21 other primary site localisations) were prospectively included in this real-life setting study. Routine plasma level testing imatinib (Cmin) and clinical data of were recorded prospectively.

RESULTS

Small bowel localisation was associated with an increased relative risk of progression of 3.09 versus stomach localisation (p=0.0255). Mean Cmin (±standard deviation) was 868 (±536) ng/ml with 75% inter-individual and 26% intra-patient variability. A Cmin threshold of 760 ng/ml defined by log-rank test was associated with longer PFS for the whole population (p=0.0256) and for both stomach (p=0.043) and small bowel (p=0.049) localisations when analysed separately. Multivariate Cox regression analysis found that Cmin above 760 ng/ml was associated with 65% reduction risk of progression (p=0.0271) in the whole population independently of the anatomical localisation.

CONCLUSION

Concentration of imatinib significantly influences duration of tumour control treatment in GIST patients with a Cmin threshold of 760 ng/ml associated with prolonged PFS in real-life setting.

Clinicopathologic Features and Clinical Outcomes of Esophageal Gastrointestinal Stromal Tumor: Evaluation of a Pooled Case Series

Clinicopathologic features and clinical outcomes of gastrointestinal stromal tumors (GISTs) in esophagus are limited, because of the relatively rare incidence of esophageal GISTs. Therefore, the aim of the current study was to investigate the clinicopathologic features and clinical outcomes of esophageal GISTs, and to investigate the potential factors that may predict prognosis.Esophageal GIST cases were obtained from our center and from case reports and clinical studies extracted from MEDLINE. Clinicopathologic features and survivals were analyzed and compared with gastric GISTs from our center.The most common location was lower esophagus (86.84%), followed by middle and upper esophagus (11.40% and 1.76%). The majority of esophageal GISTs were classified as high-risk category (70.83%). Mitotic index was correlated with histologic type, mutational status, and tumor size. The 5-year disease-free survival and disease-specific survival were 65.1% and 65.9%, respectively. Tumor size, mitotic index, and National Institutes of Health risk classification were associated with prognosis of esophageal GISTs. Only tumor size, however, was the independent risk factor for the prognosis of esophageal GISTs. In comparison to gastric GISTs, the distribution of tumor size, histologic type, and National Institutes of Health risk classification were significantly different between esophageal GISTs and gastric GISTs. The disease-free survival and disease-specific survival of esophageal GISTs were significantly lower than that of gastric GISTs.The most common location for esophageal GISTs was lower esophagus, and most of the esophageal GISTs are high-risk category. Tumor size was the independent risk factor for the prognosis of esophageal GISTs. Esophageal GISTs differ significantly from gastric GISTs in respect to clinicopathologic features. The prognosis of esophageal GISTs was worse than that of gastric GISTs.

Long-term outcome of molecular subgroups of GIST patients treated with standard-dose imatinib in the BFR14 trial of the French Sarcoma Group

BACKGROUND

The added value of tumoural genomic profiles to conventional clinico-biological factors to predict progression-free survival (PFS) and overall survival (OS) was prospectively investigated in patients with advanced gastrointestinal stromal tumours (GIST) treated in the BFR14 study.

METHODS

Of the 434 included patients, mutational analysis was performed in 322 patients. Survival analysis was performed in patients with validated mutational status.

RESULTS

Mutational status was validated in 228 patients. We identified 196 patients with tumours harbouring 200 KIT alterations (exon 11: 173 patients, exon 9: 22 patients, exon 17: 3 patients, exon 13: 2 patients; 4 patients had double KIT mutations), 6 patients with PDGFRA mutations and 26 patients with wild-type (WT) GIST genotype. On a median follow-up of 73 months, median PFS/OS were 12.3/54.9 months for WT GIST, 12.6/55 months for KIT exon 9, and 39.4 months/not reached (69.1% at 5 years) for KIT exon 11. Tumour size, female gender, KIT exon 11 mutations and CD34 positivity were independent prognostic factors for a higher PFS. A higher OS was predicted by performance status (PS) <2, low neutrophil and normal lymphocyte counts, KIT exon 11 mutations, non-advanced tumour and female gender. KIT exon 11 mutations at codons 557-558 showed better tumour response (p=0.028) but shorter PFS (p=0.0176).

CONCLUSIONS

In GIST patients, presence of a KIT exon 11 mutation is an independent prognostic factor for PFS and OS, along with gender, PS, tumour size, lymphocyte and neutrophil counts. Subsets of exon 11 mutations are associated with significantly different response patterns and PFS.

Small Bowel Stromal Tumors: Different Clinicopathologic and Computed Tomography Features in Various Anatomic Sites

Gastrointestinal stromal tumors (GISTs) can present with different clinical and immunohistochemical characteristics according to different anatomic sites. The aim of this study was to compare clinicopathologic and computed tomography (CT) features of small bowel stromal tumors located in the duodenum, jejunum, and ileum. In total, 197 patients (109 male, 88 female) with small bowel GISTs were retrospectively reviewed. All tumors had definite anatomic sites in the small bowel tract with surgical confirmation. The clinicopathologic variables included age, sex, onset of symptoms, and tumor risk category. CT variables included tumor size, degree enhancement, enhancement pattern (region of necrosis), adjacent tissue involvement, lymphadenopathy, and distant metastasis. We assessed any possible differences according to different GIST site of origin. Based on tumor size and mitotic count, the risk categories in different anatomic sites did not differ significantly between duodenal and jejunal GISTs. However, high risk ileum GISTs accounted for 66.0% of ileal cases, which was higher than duodenum cases (36.8%, P = 0.002) and jejunum cases (43.9%, P = 0.004). The mean size of GISTs in the ileum was 9.77 cm, which was significantly larger than in the duodenum (7.41 cm, P = 0.043), and in the jejunum (8.14 cm, P = 0.027). On CT images, enhancement degree appeared to gradually increase from the duodenum to the ileum in the portal phase, and the enhancement pattern presented a tendency for heterogeneity. In Conclusions, the clinicopathologic and CT features of small bowel GISTs can differ according to different primary anatomic sites.

Clinico-pathological characteristics and prognostic factors of gastrointestinal stromal tumors among a Chinese population

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms in the gastrointestinal tract, exhibiting wide variability in their biological behavior. The aim of the present study was to investigate the clinicopathological characteristics and prognostic factors of GISTs in Chinese patients. All GIST cases (n=182) retrieved from the pathology database and the archived files in Shanghai Changzheng Hospital between January 2011 and December 2014 were reviewed. The clinical symptoms, preoperative investigations, treatments, pathological characteristics and follow-up data of these patients were reviewed, and univariate and multivariate survival analyses were performed. A total of 73.1% of the GISTs were located in the stomach, and the most common three symptoms included abdominal pain (30.2%), dyspepsia (23.1%) and gastrointestinal bleeding (21.4%). Univariate analysis revealed that larger tumor size (P<0.001), higher mitotic rate (P<0.001), aggressive behavior (P<0.001), negative smooth muscle actin expression (P=0.009) and palliative resection (P<0.001) contributed toward poor overall survival (OS). In addition, non-gastric disease location (P<0.001), larger tumor size (P<0.001), higher mitotic rate (P=0.004), aggressive behavior (P<0.001) and palliative resection (P<0.001) were associated with poor relapse-free survival (RFS). Multivariate analysis indicated that mitotic rate [hazard ratio (HR=3.761, P=0.015)] and aggressive behavior (HR=3.916, P=0.010) were independent risk factors for OS, while non-gastric location (HR=4.740, P=0.002) and aggressive behavior (HR=4.009, P=0.004) were independent risk factors for RFS. The present study provided information on the clinicopathological characteristics and epidemiology of GISTs in the Chinese population. Non-gastric disease location, higher mitotic rate and tumor metastasis or local invasion prior to treatment were identified as predictors of a poor prognosis.

Gastrointestinal stromal tumour metastatic to the epididymis

Gastrointestinal stromal tumours (GIST) are mesenchymal neoplasms with a propensity to metastasise to the liver and peritoneal cavity. Since the advent of tyrosine kinase inhibitors, outcomes for patients with metastatic GIST have improved dramatically. Secondary to the longevity in survival, patients may develop metastatic disease in very unusual locations, which poses significant diagnostic dilemmas and management challenges. We report a case of a patient with GIST who presented with an epididymal metastasis manifesting as a scrotal mass. Resistance to targeted medical therapies continues to pose a challenge, and our case highlights the importance of a multidisciplinary approach in such patients, including long-term follow-up.

Surgery for gastrointestinal stromal tumors (GISTs) of the stomach and small bowel: short- and long-term outcomes over three decades

BACKGROUND

Many studies on gastrointestinal stromal tumors (GISTs) derive from tertiary referral centers, but few examine strictly population-based cohorts. Thus, we evaluated the clinical features, surgical treatments, clinical outcomes, and factors predicting the survival of patients with GISTs in a population-based series.

METHODS

Patients with GISTs diagnosed at Stavanger University Hospital over three decades (1980-2012) were analyzed. Data were retrieved from hospital records. Descriptive statistics and survival analyses (Kaplan-Meier) are presented. A limited number of colorectal GISTs (n = 6) restricted most analyses to those with a gastric or small bowel location.

RESULTS

Among 66 patients surgically treated for GISTs, 60 patients (91 %) had either a gastric or a small bowel localization. Females comprised 61 %. The median age at diagnosis was 63 (range, 15-88) years. Clinical symptoms were recorded in 43 patients (65 %). Complete tumor resection was achieved in 85 % of the patients. During follow-up, 6 patients were surgically treated for local recurrence or metastatic disease. The median follow-up time was 6.1 years. At last follow-up, 30 patients (46 %) were deceased, 10 of whom died from GISTs. The median overall survival was 10.4 years. For GISTs with a gastric or small bowel location, a 1- and 5-year disease-specific survival of 100 and 96 %, and a relapse-free survival of 96 and 78 % were observed. Male gender, incidental diagnosis, smaller tumor size, a low mitotic rate, an intact pseudocapsule, low-risk categorization, and an early stage were significantly associated with improved outcomes.

CONCLUSION

Surgery in a low-volume, population-based setting yields enhanced long-term disease and recurrence-free survival for patients with GISTs of the stomach or small bowel. Incidental diagnosis, complete tumor resection, and low-risk categorization are good predictors of long-term prognosis.