Prognostic factors after surgery of primary resectable gastrointestinal stromal tumours

Gastrointestinal stromal tumor in North Africa and the middle east: updates in presentation and management from an 11-year retrospective cohort

OBJECTIVES

This study described the epidemiological, clinical, and survival profiles of patients with gastrointestinal stromal tumor (GIST) in North Africa and the Middle East (AfME).

METHODS

This regional, multicenter, observational, retrospective study collected 11-year data on demographics, medical history, disease characteristics, current treatment approaches of GIST, the safety of the most common tyrosine kinase inhibitors (TKIs), second cancers, and survival status.

RESULTS

Data of 201 eligible patients were analyzed: mean age was 56.9 ± 12.6 years; 111 (55.2%) patients were men, 21 (10.4%) patients had previous personal malignancy. The most common clinical presentation of GIST was dysphagia [92 (45.8%) patients]. The stomach was the most common primary site in 120 (60.7%) patients, 171 (85.1%) patients had localized disease at diagnosis. 198 (98.5%) GIST cases were CD117/CD34-positive. Imatinib was used in the neoadjuvant (18/21 patients), adjuvant (85/89 patients), and first-line metastatic treatment (28/33 patients) settings. The most common non-hematological toxicity associated with TKIs was vomiting in 32/85 (37.6%) patients. Overall, 100 (49.8%) patients (95%CI: 42.8-56.7%) were alive and disease-free while 30 (14.9%) patients were alive with active disease.

CONCLUSION

Presentation of GIST in our AfME population is consistent with global reports, being more frequent in patients >50 years old and having the stomach as the most common primary site. Unlike what is usually reported, though, we did have more patients with lymphatic spread of the disease. Despite the global trend and advances in the treatment of GIST according to molecular profile, this is still far to happen in our population given the lack of access to molecular profiles and the high associated cost.

A New Online Dynamic Nomogram: Construction and Validation of a Predictive Model for Distant Metastasis Risk and Prognosis in Patients with Gastrointestinal Stromal Tumors

BACKGROUND

Gastrointestinal stromal tumor (GIST) is the most common sarcoma of the digestive tract, among which patients with distant metastases tend to have a poor prognosis. This study aimed to develop a model for predicting distant metastasis in GIST patients and to develop two models for monitoring overall survival (OS) and cancer-specific survival (CSS) in GIST patients with metastasis. This would allow us to develop an optimal, individualized treatment strategy.

METHODS

We reviewed demographic and clinicopathological characteristics data from 2010 to 2017 of patients diagnosed with GIST in the Surveillance, Epidemiology, and End Results (SEER) database. The data of the external validation group was reviewed from the Forth Hospital of Hebei Medical University. Univariate and multivariate logistic regression analyses were used to confirm the independent risk factors for distant metastasis in the GIST patients, and univariate and multivariate Cox regression analyses were performed to identify the independent prognostic factors for OS and CSS in the GIST patients with distant metastasis. Subsequently, three web-based novel nomograms were developed, which were evaluated by the receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA).

RESULTS

Of the 3639 patients who met the inclusion criteria, 418 (11.4%) had distant metastases. The risk factors for distant metastasis in GIST patients included sex, primary site, grade, N stage, tumor size, and mitotic count. For OS, the independent prognosis factors for GIST patients with metastasis included age, race, marital, primary site, chemotherapy, mitotic count, and metastasis at the lung, and for CSS, age, race, marital, primary site, and metastasis at the lung were the independent prognosis factors. Three web-based nomograms were constructed based on these independent factors, respectively. The ROC curves, calibration curves, and DCA were performed in the training, testing, and validation sets which confirmed the high accuracy and strong clinical practice power for the nomograms.

CONCLUSION

Population-based nomograms can help clinicians predict the occurrence and prognosis of distant metastases in patients with GIST, which may be helpful for clinicians to formulate clinical management and appropriate treatment strategies.

Risk factors for the failure of endoscopic resection of gastric submucosal tumors: a long-term retrospective case-control study

OBJECTIVE

Endoscopic resection (ER) is an effective treatment method for gastric submucosal tumors (G-SMTs), but endoscopic resection failure requires emergency surgery. The purpose of this study was to assess potential risk factors for endoscopic resection failure.

METHODS

A total of 1041 patients with G-SMT undergoing endoscopic resection were enrolled. Twenty-five patients in whom endoscopic resection failed, requiring a transition to surgery midway through the operation, were included in the failed group, and 1016 patients who received successful endoscopic resection were included in the successful endoscopic resection group. Baseline and lesion characteristics were recorded, and the differences in tumor characteristics and risk factors for resection failure of G-SMT were analyzed. Sensitivity analysis was performed to detect the stability of the indicator.

RESULTS

Of the 1041cases included, there were 25 cases (2.4%) of failed endoscopic resection. Binary logistic analysis showed that the independent risk factors included tumors originating from deep muscularis propria(OR = 14.42, 95% CI 4.47-46.52), size > 3 cm (OR = 7.75, 95% CI 2.64-22.70), exophytic growth pattern (OR = 4.98, 95% CI 1.62-15.29), endoscopist with less experience (OR = 5.99, 95% CI 1.07-12.19), and irregular borders (OR = 4.13, 95% CI 1.40-12.19). The stable risk factors were tumors size, tumor origin and growth pattern according to sensitivity analysis.

CONCLUSIONS

Tumors originating from the deep muscularis propria, tumor size > 3 cm, endoscopists with less experience, an exophytic growth pattern, and irregular boundaries were found to be independent risk factors for endoscopic resection failure. To reduce the risk of endoscopic resection failure, physicians should carefully evaluate G-SMT characteristics preoperative.

Treatment of gastrointestinal stromal tumors: A single-center experience

OBJECTIVE:

Gastrointestinal stromal tumors are the most common mesenchymal tumors of the gastrointestinal tract. We aimed to examine the clinical characteristics and treatment outcomes of patients diagnosed with gastrointestinal stromal tumor (GIST) who were followed up and treated in our center.

METHODS:

This study retrospectively evaluated the clinical characteristics, disease stages, administered treatments, and treatment responses of 67 patients diagnosed with GIST who presented to our center between 2007 and 2015.

RESULTS:

Of the 67 patients included in our study, 24 (35.8%) were female and 43 (64.2%) were male. Median age at diagnosis was 54 years (23–86). Primary tumor localization was the stomach in 38.8% (n=26), small intestine in 46.2% (n=31), colorectal in 6% (n=4), and extra-gastrointestinal in 9% (n=6) of the patients. At diagnosis, 19 patients (28.4%) were at a metastatic stage. Fifty-seven patients (85.1%) underwent surgery. Thirty-three patients received one line, 20 patients received two lines, and 12 patients received three lines of treatment. The first-line treatment resulted in complete response in 12 patients (36.4%), partial response in 15 patients (45.5%), stable disease in 5 patients (15.2%), and progression in 1 patient (3%). Progression-free survival (PFS) was 36 months for the first-line treatment. The second-line treatment resulted in partial response in 7 patients (35%), stable disease in 12 patients (60%), and progression in 1 patient (5%). PFS was 12 months for the second-line treatment. The third-line treatment resulted in complete response in 1 patient (8.3%), partial response in 3 patients (25%), stable disease in 5 patients (41.7%), and progression in 3 patients (25%). PFS was 9 months for the third-line treatment. The fourth-line treatment resulted in stable disease in 4 patients (80%) and progression in 1 patient (20%). PFS was 4 months for the fourth-line treatment. Overall survival was 90 months for all patients.

CONCLUSION:

The use of tyrosine kinase inhibitors such as imatinib has a significant favorable effect on the prognosis in the treatment of GISTs, both in adjuvant therapy and in advanced stage disease.

Simultaneous Integrated Boost Intensity-Modulated Radiotherapy for Locally Advanced Drug-Resistant Gastrointestinal Stromal Tumors: A Feasibility Study

Background

As an emerging clinical problem, locally advanced drug-resistant gastrointestinal stromal tumors (LADRGISTs) has relatively few therapeutic schemes. Although radiotherapy is not often considered for GISTs, it could be a valuable contributing modality. The aim of our study is to explore a safe and effective radiation regimen for LADR-GISTs.

Methods

Three patients with LADR-GISTs were treated with simultaneous integrated boost intensity-modulated radiation therapy (SIB-IMRT) plans. In the SIB-IMRT plans, gross target volume (GTV) was divided into GTV-outer, GTV-mid, and GTV-center. And the prescribed dose of planning gross target volume (PGTV) and GTV-outer were both set to 50.4 Gy in 28 fractions. GTV-mid and GTV-center were simultaneously boosted to 60–62 Gy and 62–64 Gy respectively. For comparison purposes, conventional IMRT (Con-IMRT) plans with uniform dose distribution were generated for same optimization objectives without a dose boost to GTV-mid and GTV-center. All plans were optimized to make sure that deliver at least 95% of the prescription dose was delivered to PGTV. Isodose distribution, dose profiles, conformity indexes (CIs), monitor units (MUs), and dose volume histogram (DVH) was evaluated for each individual patient. After the three patients were treated with SIB-IMRT plans, the relative changes in the tumor size and CT values by CT scanning were also tracked.

Results

Compared with Con-IMRT plans, SIB-IMRT plans saw a significant increase from D₉₅ to D₂ of the GTV. With steeper dose gradients in the dose profiles, SIB-IMRT plans had GTV-mid and GTV-center accumulated with higher dose mainly by delivering extra 93 MUs in average. However, there was no significant difference in CIs and organs at risks (OARs) DVH. The relative changes in tumor size and CT values of the three patients in follow up were up to the Choi criteria and the three patients were all assessed as partial response.

Conclusions

The proposed SIB-IMRT may be a potential technique for achieving objective response and prolonging survival of selected GISTs patients.

Do microscopic surgical margins matter for primary gastric gastrointestinal stromal tumor?

BACKGROUND

Although tumor size and mitotic rate are established prognostic factors for worse survival in patients undergoing surgical resection for gastric gastrointestinal stromal tumors, the impact of microscopic margins, or R1 resection, is not completely established.

METHODS

Patients who received no neoadjuvant therapy and underwent surgical resection for stage I to III gastric gastrointestinal stromal tumors were identified from the 2010 to 2013 National Cancer Database and divided into 2 cohorts, R0 and R1 resections. Cox proportional hazards ratio and Kaplan Meier survival estimates were utilized to analyze 5-y overall survival.

RESULTS

Of 2,084 patients, those with R1 resection (57, 2.7%) were more likely to have tumors >10 cm (28.1% vs 11.9%, odds ratio 3.51, P = .017) and stage III disease (26.3% vs 11.2%, odds ratio 2.26, P = .047). Although margin status was associated with higher risk tumors, it was not associated with receipt of adjuvant therapy. After multivariate Cox regression, R1 and R0 patients did not have a difference in 5-y overall survival (82.5% vs 88.6%, hazards ratio 1.26, P = .49). When stratified by stage of disease, there remained no difference in survival across all stages when comparing R1 and R0 patients.

CONCLUSION

Positive microscopic margins are uncommon but do not appear to impact survival outcomes in patients with resected localized gastric gastrointestinal stromal tumors.

Comparison between laparoscopic and endoscopic resections for gastric submucosal tumors

BACKGROUND/AIMS

Open resection/laparoscopic resection (LR) is the traditional treatment of gastric submucosal tumor (G-SMT). The endoscopic resection (ER) technology provides good results for G-SMT treatment but lacks sufficient evidence-based evidence. This retrospective study aimed to compare the clinical efficacy of ER [endoscopic submucosal dissection (ESD), endoscopic submucosal excavation (ESE), and endoscopic full-thickness resection (EFR)] and LR [laparoscopic wedge resection (LWR) and laparoscopic subtotal gastrectomy (LSG)] for G-SMT.

PATIENTS AND METHODS

From January 2013 to January 2017, data of patients with G-SMT with tumor diameter <5 cm were collected from the database of The Affiliated Hospital of Qingdao University and classified based on surgical methods. Demographics, tumor characteristics, surgical outcomes, complications and tumor recurrence were recorded and compared.

RESULTS

Overall, 275 patients with G-SMT were enrolled: 152 underwent ER (ESD, n = 65; ESE, n = 23; EFR, n = 61) and 123 underwent LR (LWR, n = 93; LSG, n = 30). Age, sex, R0 resection rate, tumor location, type, recurrence and complications were not statistically significant (P > 0.05). The ER group had a significantly higher percentage of intraluminal tumor (94.1% vs 62.4%) and smaller tumor size (1.8 ± 0.8 vs 3.4 ± 1.2 cm) than the LR group. The ER group had less muscular tumors than the LR group (54.6% vs 70.7%). The ER group had no serosal tumor. The ER group had shorter hospitalization time, postoperative hospital stay and diet recovery time. The LR group had shorter operation time, less cost and less blood loss.

CONCLUSION

ER and LR are safe and effective treatments for SMT. For small intraluminally growing SMT, ER is better than LR.

Effect of the imatinib treatment regimen on the postoperative prognosis of patients with high-risk gastrointestinal stromal tumors

Background: Surgical resection is the standard treatment for localized and potentially resectable gastrointestinal stromal tumors (GISTs), If the postoperative pathology diagnosis indicates that patients are at high risk of recurrence, they should be treated with imatinib. Even though the introduction of imatinib substantially improved the outcome of GIST patients, it is unclear whether different imatinib treatment regimens affect patients' survival. Methods: This retrospective study included 120 patients who underwent tumor resection for high-risk GISTs between January 2009 and October 2018. The patients were divided into three groups: one group of patients received postoperative imatinib adjuvant therapy regularly (regular treatment group); the second group was not treated with imatinib until they were found to have disease progression (observation group); the third group was treated with postoperative imatinib adjuvant therapy irregularly (irregularly treatment group). The progression-free survival (PFS) and overall survival (OS) were compared between the three groups, and the prognostic risk factors were analysed by the Cox regression model. Results: The median PFS was 45 months (range: 25-59). The 3- and 5-year PFS values were 71.3% and 49.9%, respectively. The PFS in the regular group was longer than in the observation group and irregular group (P<0.001). The median OS was 59 months (range:47-78). The 3- and 5-year OS values were 91.6% and 84.2%, respectively. There were no differences in OS among the three groups (P=0.150). The extent of radical resection (P<0.001) and intraoperative tumor rupture (P=0.005) were independent prognostic factors influencing OS. Conclusions: Irregular administration of imatinib was associated with a worse PFS, but it did not affect the OS of patients with high-risk GISTs. Avoiding intraoperative tumor rupture and R0 resection were associated with better survival.

Gastrointestinal Stromal Tumors of the Stomach and Esophagus

Gastrointestinal stromal tumors (GISTs) arise anywhere along the gastrointestinal tract, most commonly as a result of c-kit or PDGFRA proto-oncogene mutations. Surgical resection is an important component of treatment. However, molecular profiling of GISTs has provided many insights into adjuvant and neoadjuvant therapy options. Imatinib, the most frequently studied medical therapy, has been shown in numerous studies to provide benefit to patients in both the neoadjuvant and adjuvant setting. Interval imaging is an important component of the treatment of GISTs and national surveillance recommendations should be followed.

Is the Surgical Margin in Gastrointestinal Stromal Tumors Different?

Background

Radical surgical excision is the mainstay of therapy of primary, nonmetastatic gastrointestinal stromal tumors (GIST) and margin status after surgery is a significant prognostic factor.

Methods and Results

The aim of this paper is to review principles in primary GIST surgery, i.e. differences between R0, R1, and R2 resection, to describe how surgical margin status and tumor intraperitoneal rupture influence the patients' outcome, and how this may be effected by neoadjuvant and adjuvant treatment in locally advanced tumors. A systematic search of literature published between 2000 and 2018 was performed regarding this topic.

Conclusion

Correct interpretation of margin status after surgery can be affected by many factors during operation and preparation of tissue.

Radiotherapy for Gastrointestinal Stromal Tumors

OBJECTIVE

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors of the gastrointestinal tract, which frequently cause intraabdominal metastases. The current standard of care is surgery for localized cases, and adjuvant imatinib is recommended for tumors with a high risk of recurrence. To date, radiotherapy has not been commonly accepted as a part of multimodality treatment approach other than palliation. However, recently published case reports and some small series suggest that radiotherapy is a valuable option for controlling locally progressive, drug-resistant disease. The aim of this review is to provide a viewpoint from a radiation oncologist concerning the management of GISTs, especially rectal GIST, and clarify the role and technical aspects of radiotherapy in the treatment approach.

DATA SOURCES

A comprehensive search in PubMed using the keywords "radiotherapy for rectal GIST" and "rectal GIST" was undertaken. The literature search included the related articles after 1995.

STUDY SELECTION

The main articles including rectal GIST case reports and GIST series containing rectal cases were the primary references.

RESULTS

Surgery is the mainstay of treatment. However, to date, radiotherapy is included in the multidisciplinary treatment strategy of rectal GISTs in some circumstances with palliative, adjuvant, or definitive intent using different treatment doses and fields.

CONCLUSIONS

Recently reported long-term local control rates indicate that GIST is a radiosensitive disease. This makes radiotherapy a valuable alternative in GIST management with curative intent, especially in patients who (1) cannot tolerate or are resistant to chemotherapy agents, (2) have an unresectable disease, (3) have a gross or microscopic residual disease after surgery, and (4) have a recurrent disease.

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.

Primary Small Bowel GIST Presenting as a Life-Threatening Emergency: A Report of Two Cases

Gastrointestinal stromal tumor (GIST) is a rare stromal neoplasm, which represents the most common mesenchymal tumor of the gastrointestinal tract. It is characterized by indolent clinical symptoms, although it can present as a life-threatening emergency. Herein, we present two cases of primary small bowel GIST treated at our department. A 68-year-old female patient presented to our emergency department with a diffuse abdominal pain of acute onset. Imaging studies revealed a mass at proximal jejunum, with a nearby free air and fluid. At surgery, a mass of 9 cm was found at proximal jejunum, 3 cm distal to the treitz ligament, with perforation on the lateral wall of the mass. En bloc resection was performed. Pathology report was positive for gastrointestinal stromal tumor. A 70-year-old male patient presented to our emergency department with 3 days of dark tarry stool and few hours of hematochezia. Computed tomography angiography revealed a mass at the pelvis, with calcifications, attached to the distal ileum, with intraluminal blush of intravenous iodine. At surgery, a mass of 8 cm at the distal ileum was found. Resection of the mass along with a 20 cm of ileum was completed. Histopathology report was positive for malignant gastrointestinal stromal tumor.

Supraclavicular lymph node metastases from malignant gastrointestinal stromal tumor of the jejunum: A case report with review of the literature

Gastrointestinal stromal tumors (GISTs) represent the most common mesenchymal tumors of the alimentary tract. These tumors may have different clinical and biological behaviors. Malignant forms usually spread via a hematogenous route, and lymph node metastases rarely occur. Herein, we report a patient with a jejunal GIST who developed supraclavicular lymph node metastasis. We conclude that lymphatic diffusion via the mediastinal lymphatic station to the supraclavicular lymph nodes can be a potential metastatic route for GISTs.

Cytohistological and immunohistochemical characteristics of spindle-shaped mesenchymal neoplasms occurring in the gastrointestinal tract

The purpose of the present review is to analyze the cytohistological and immunohistochemical characteristics of spindle-shaped mesenchymal gastrointestinal neoplams (MGNs), a group of unusual neoplastic conditions with different biological behavior. These tumors exhibit clinical pictures strictly related to the site of origin and dimensions, even if they appear generally with an intramural localization. This latter point may suggest an useful application of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), mainly followed by the cell-block procedure (CBP) in the differential diagnostic approach. First of all, we discuss the most common entity of MGNs represented by gastrointestinal stromal tumors (GISTs), analyzing the morphologic characteristics and stressing the strength of immunohistochemical algorithm for diagnostic purposes. Successively, we have reported the less common group of spindle-shaped MGNs comprehensive of those arising elsewhere the soft tissues, such as leiomyomas, leiomyosarcomas, schwannomas, inflammatory myofibroblastic tumor and intra-abdominal desmoid fibromatosis. Finally, very uncommon spindle-shaped MGNs, like clear cell, follicular dendritic cell, undifferentiated pleomorphic and radiation-induced sarcomas as well as spindle cell dedifferentiated liposarcomas, have been briefly mentioned.

Clinicopathologic features and prognosis of primary gastrointestinal stromal tumor patients under 35 years of age: A 10-year retrospective study

OBJECTIVES

To investigate gastrointestinal stromal tumor (GIST) clinicopathologic characteristics in young adults.

METHODS

Clinicopathologic data from GIST patients under 35 years diagnosed at our hospital from January 2005 to December 2014 were retrospectively collected.

RESULTS

Thirty-one (5.3%, 31/585) patients were included; 17 (54.8%) were female. The most common presentation and primary tumor site were gastrointestinal bleeding (n = 18, 58.1%) and the small intestine (n = 13, 41.9%), respectively. Fifteen (48.4%) GISTs were classified as having a high relapse risk; two (6.4%), intermediate; nine (29.0%), low; and five (16.1%), very low. All patients underwent tumor resection. With a median follow-up of 51 months for 20 (64.5%) patients, 12 (60%) were given imatinib methylate as adjuvant therapy. One (5%) patient died of peritoneal GIST dissemination, four (20%) developed abdominal recurrences, two (10%) had hepatic metastasis, and thirteen (65%) were disease free. The 5-year disease-free survival rate was 51.2%.

CONCLUSIONS

GISTs rarely occur in young adults. The most common location is the small intestine. A slight female predominance was observed in the current study. Adjuvant therapy longer than the recommended duration may be beneficial for GISTs with a high relapse risk. Combined targeted therapy and surgery is appropriate for recurrent and metastatic GISTs in select patients. J. Surg. Oncol. 2016;114:977-981. © 2016 Wiley Periodicals, Inc.

Hybrid NOTES: Combined Laparo-endoscopic Full-thickness Resection Techniques

Advances in laparoscopic surgery and therapeutic endoscopy have allowed these minimally destructive procedures to challenge conventional surgery. Because of its theoretic advantages and technical feasibility, laparoendoscopic full-thickness resection is considered to be the most appropriate option for subepithelial tumor removal. Furthermore, combination of laparoscopic and endoscopic approaches for treatment of neoplasia can be important maneuvers for gastric cancer resection without contamination of the peritoneal cavity if the sentinel lymph node concept is established. We are certain that the use of laparoendoscopic full-thickness resection will provide valuable experience that will allow operators to safely develop endoscopic full-thickness resection skills.

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.

MDCT features of succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumours

OBJECTIVE

To describe the multidetector CT (MDCT) features and metastatic pattern of succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumours (GISTs).

METHODS

In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant study, we retrospectively identified 34 patients (20 females; mean age, 34 years; range, 12-59 years) with histopathology-confirmed SDH-deficient GIST, who were seen at our institution from 1999 through 2012. MDCT of primary tumour in 8 patients and follow-up imaging in all 34 patients over median follow-up of 106 months [interquartile range (IQR), 52-175 months] were reviewed by two radiologists in consensus. Clinical information was extracted from electronic medical records.

RESULTS

Primary tumour in all 34 patients was located in the stomach. Mean tumour size (n = 8) was 9.6 cm (range, 8-14 cm). Primary tumours were lobulated, variable in growth pattern, hypo- (1/8) to isodense (7/8) and similar in enhancement to the skeletal muscle. Two were multifocal, four of eight had necrosis and one of eight had haemorrhage. Tumour rupture with haemoperitoneum and tumour-bowel fistula was noted in one patient each. During follow-up, 12/34 patients developed tumour in surgical bed, and 28/34 patients developed metastases. Most common sites of metastases were the liver (24/34), peritoneum (20/34) and lymph nodes (18/34). Carney triad and Carney-Stratakis syndrome were noted in 5/34 and 1/34 patients, respectively. At the time of writing, six patients had deceased at a median interval of 109 months (IQR, 54-126 months).

CONCLUSION

SDH-deficient GISTs occur in young patients, commonly arise in stomach, can be multifocal and may be associated with Carney triad or Carney-Stratakis syndrome. They frequently metastasize to lymph nodes in addition to the liver and peritoneum and are associated with indolent course despite metastatic spread.

ADVANCES IN KNOWLEDGE

The presence of features unusual for conventional GIST on imaging should alert the radiologist for the possibility of SDH-deficient GIST, especially, because SDH-deficient GISTs are resistant to imatinib. Young age at diagnosis, prolonged survival, association with Carney triad and Carney-Stratakis syndrome and occurrence of concurrent renal cell carcinoma and thyroid malignancies necessitates long-term follow-up of patients with SDH-deficient GISTs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Single-incision laparoscopic partial gastrectomy for gastric submucosal tumors without compromising transumbilical stapling

INTRODUCTION

Although SILS has become an increasingly popular type of surgery, its application for gastric submucosal tumors (SMT) has been only sporadically reported. We herein describe 12 recent cases with gastric SMT located in the greater curvature or anterior wall. The aim is to validate technical feasibility and safety of single-incision laparoscopic partial gastrectomy. Thus far, this is one of the largest series of patients with gastric SMT who underwent SILS.

METHODS

From July 2009 to April 2013, single-incision laparoscopic partial gastrectomy was attempted in 12 consecutive patients with gastric SMT. Three trocars were assembled in the umbilical incision, and the lesion was mobilized and staple-resected with endoscopic stapling devices.

RESULTS

SILS surgery was successfully completed without any additional trocars. The median operating time was 96.5 min, and median blood loss was 7.5 mL. The median tumor size was 30 mm, with histopathologic diagnosis of gastrointestinal stromal tumor (10) and schwannoma (2). There was no immediate postoperative morbidity. During a median follow-up of 12 months, all patients were on full regular diet without any gastrointestinal symptoms.

CONCLUSION

SILS with transumbilical gastric stapling is a safe and practical alternative to conventional multiport laparoscopy in patients with gastric SMT, except for cases originating in the lesser curvature and close to the cardia/ pylorus.

Concomitant gastrointestinal stromal tumor of the stomach and gastric adenocarcinoma in a patient with billroth 2 resection

Background. With this study we focus on the etiopathogenesis and on the therapy of the simultaneous occurrence of Gastric gastrointestinal stromal tumor (gGIST) and adenocarcinoma of the stomach in a patient with Billroth II gastric resection (BIIGR). We report the first case of this event and a review of the literature. Methods. A 70-year-old man with a BIIGR, affected by adenocarcinoma of the stomach, was successfully treated with total gastrectomy. The histological examination showed a gastric adenocarcinoma with a synchronous GIST sized 2 cm and S-100, CD117, and CD34 positive. The mutation of PDGFR gene was detected. Discussion. This tumor is a rare mesenchymal neoplasm of the gastrointestinal tract. Few cases of synchronous gastric adenocarcinoma and GIST are observed in the literature and no case in patients with BIIGR. Various hypotheses have been proposed to explain this occurrence. It is frequently attributed to Metallothioneins genes mutations or embryological abnormalities, but this has not been proven yet. We suggest a hypothesis about the etiopathogenesis of this event in a BIIGR patient. Conclusion. GIST may occur synchronously with gastric adenocarcinoma. This simultaneous occurrence needs more studies to be proven. The study of Cajal cells' proliferation signalling is crucial to demonstrate our hypotesis.

Laparoscopic versus open resection of gastric gastrointestinal stromal tumors

The aims of this study were to explore whether laparoscopic surgical resections of gastric gastrointestinal stromal tumors (GISTs) would produce better perioperative and similar oncologic outcomes compared with open surgical resection in Chinese patients. Thirty-six gastric GISTs cases were divided into a minimally invasive laparoscopic group and open resection group, depending on the surgical approach that was used. The general preoperative information, operative time, incision length, intraoperative blood loss, postoperative time to first flatulence, postoperative complications, postoperative hospital stay, total hospitalization costs, and such follow-up data as recurrence, metastasis, and mortality rates were compared between two groups. Among the 36 gastric GISTs, 15 received laparoscopic surgical treatment (laparoscopy group, n=15), and 21 received routine open resection treatment (open resection group, n=21). The laparoscopy group and the open resection group showed statistically significant differences (P<0.05) in incision length (7.8±2.3 vs. 16.9±3.8 cm), postoperative time to first flatulence (3.8±1.3 vs. 5.1±2.1 d), postoperative hospitalization time (7.6±2.5 vs. 11.3±3.7 d), and total cost of hospitalization (RMB 28,239±5,521 vs. RMB 23,761±5,362). There were no statistically significant differences (P>0.05) between the laparoscopy group and the open resection group in operative time (147.8±59.3 vs. 139.2±62.1 min) and intraoperative blood loss (149.8±98.9 vs. 154.2±99.3 mL). Both groups had no postoperative complications, no recurrence and metastasis, and no postoperative mortality. There were no statistically significant differences between the two groups in postoperative complications, postoperative recurrence and metastasis, and postoperative mortality. In conclusion, compared with open resection, the laparoscopic resection of gastric GISTs offers the advantages of less trauma, faster recovery, and shorter hospital stay.

Clinicopathological features and prognostic factors of rectal gastrointestinal stromal tumors

AIM

Rectal gastrointestinal stromal tumor (GIST) was a rare disease. This study sought to summarize clinicopathological features and prognostic factors of rectal GISTs.

METHODS

Clinicopathological characteristics and prognostic factors of rectal GISTs were investigated by reviewing patients undergoing curative resection at the Fudan University Shanghai Cancer Center between 1986 and 2010.

RESULTS

Twenty-one patients, 15 male and 6 female, were included. The mean age of onset was 51 years. The most common initial presentation was hematochezia (7 cases). Eleven patients underwent radical resection, and the other 10 received local resection. No lymph node metastases were identified. All cases were positive for CD117. Seventeen patients were classified as high National Institutes of Health (NIH) risk category. The 5-year disease-free survival (DFS) and overall survival were 33 and 46 %, respectively. Fifteen cases had recurrence postoperatively. Both univariate and multivariate analyses demonstrated the NIH risk category (p = 0.028) and hematochezia symptom (p = 0.014) were independent prognostic factors of the DFS of patients.

CONCLUSIONS

Hematochezia was the most common initial symptom. Over 50 % of patients received radical surgery. More than 80 % of patients were at high NIH risk of recurrence. Hematochezia symptom and high NIH risk category indicated poor prognosis of rectal GISTs.

Limited resection for duodenal gastrointestinal stromal tumors: Surgical management and clinical outcome

AIM: To analyze our experience in patients with duodenal gastrointestinal stromal tumors (GIST) and review the appropriate surgical approach.

METHODS: We retrospectively reviewed the medical records of all patients with duodenal GIST surgically treated at our medical institution between 2002 and 2011. Patient files, operative reports, radiological charts and pathology were analyzed. For surgical therapy open and laparoscopic wedge resections and segmental resections were performed for limited resection (LR). For extended resection pancreatoduodenectomy was performed. Age, gender, clinical symptoms of the tumor, anatomical localization, tumor size, mitotic count, type of resection resectional status, neoadjuvant therapy, adjuvant therapy, risk classification and follow-up details were investigated in this retrospective study.

RESULTS: Nine patients (5 males/4 females) with a median age of 58 years were surgically treated. The median follow-up period was 45 mo (range 6-111 mo). The initial symptom in 6 of 9 patients was gastrointestinal bleeding (67%). Tumors were found in all four parts of the duodenum, but were predominantly located in the first and second part of the duodenum with each 3 of 9 patients (33%). Two patients received neoadjuvant medical treatment with 400 mg imatinib per day for 12 wk before resection. In one patient, the GIST resection was done by pancreatoduodenectomy. The 8 LRs included a segmental resection of pars 4 of the duodenum, 5 wedge resections with primary closure and a wedge resection with luminal closure by Roux-Y duodeno-jejunostomy. One of these LRs was done minimally invasive; seven were done in open fashion. The median diameter of the tumors was 54 mm (14-110 mm). Using the Fletcher classification scheme, 3/9 (33%) tumors had high risk, 1/9 (11%) had intermediate risk, 4/9 (44%) had low risk, and 1/9 (11%) had very low risk for aggressive behaviour. Seven resections showed microscopically negative transsection margins (R0), two showed positive margins (R1). No patient developed local recurrence during follow-up. The one patient who underwent pancreatoduodenectomy died due to progressive disease with hepatic metastasis but without evidence of local recurrence. Another patient died in complete remission due to cardiac disease. Seven of the nine patients are alive disease-free.

CONCLUSION: In patients with duodenal GIST, limited surgical resection with microscopically negative margins, but also with microscopically positive margins, lead to very good local and systemic disease-free survival.

Feasibility and oncological outcomes of limited duodenal resection in patients with primary nonmetastatic duodenal GIST

INTRODUCTION

Duodenal gastrointestinal stromal tumors (GISTs) are rare but still represent approximately 30 % of primary duodenal tumors. This study aimed to audit the feasibility and oncological outcomes of limited duodenal resection in patients with primary nonmetastatic duodenal GIST.

METHODS

Twelve patients who underwent surgery at our institution since 2002 were prospectively followed up. The duodenal GISTs were located in the first (n = 3), second (n = 1), third (n = 3), and fourth of duodenum (n = 1). Involving both D1/D2 (n = 2), D2/D3 (n = 1), and D3/D4 (n = 1). The primary endpoint for this analysis was disease-free survival.

RESULTS

The commonest presentation was melena and anemia (83 %). All the patients underwent limited resection; six wedge resections with primary closures and six segmental resections with end-to-end anastomosis. The median tumor size was 8 cm (range, 5-16 cm). According to Fletcher scale, two GISTs were low risk, while 10 patients were intermediate and high risk. The latter received adjuvant therapy. All the patients had a complete resection with no postoperative mortality. One patient had three liver metastases 4 months after limited resection and had partial hepatectomy. After median follow-up of 45 (15-78) months, all patients are alive and disease free.

CONCLUSION(S)

When technically feasible, limited resection should be considered a reliable and curative option for duodenal GIST achieving satisfactory disease-free survival. The technical feasibility is guided by the tumor size, possible adjacent organ involvement, and its exact anatomical location.

Current management of gastrointestinal stromal tumors--a comprehensive review

BACKGROUND

Gastrointestinal stromal tumors (GISTs) comprise < 1% of all gastrointestinal (GI) tumors, but GISTs are the most common mesenchymal tumors of the GI tract. Dramatic changes in clinical practice have been observed in the last decade. This review highlights the overall management of GIST and its recent developments.

METHOD

We identified literature by searching Medline and PubMed from January 1995 to December 2011 using the keywords "gastrointestinal stromal tumors", "GIST", "imatinib" and "tyrosine kinase inhibitor". Additional papers were identified by a manual search of the references from the key articles. There were no exclusion criteria for published information to the topics.

RESULTS

For localized primary GISTs, surgical resection is the mainstay of therapy. The 5-year survival rate after complete resection of GISTs is approximately 50%-65%. Many factors including tumor size, mitotic rate, tumor location, kinase mutational status and occurrence of tumor rupture have been extensively studied and proposed to be predictors of survival outcomes. Adjuvant imatinib is proposed as an option for those patients with a substantial risk of relapse. Unresectable metastatic or recurrent GIST can be treated with a tyrosine kinase inhibitor, imatinib, with a remarkable response (50%-70%) and prolonged survival (median progression-free survival: 18-20 months; median overall survival: 51-57 months). The standard approach in the case of tumor progression on 400 mg once per day is to increase the imatinib dose to 400 mg twice per day as permitted by toxicity. Use of a second-line targeted agent, sunitinib, in patients with advanced GIST who fail (or are intolerant of) imatinib therapy is advised.

CONCLUSION

Treatment for GISTs has become increasingly complex because of the growing understanding of its biology. A multidisciplinary team that includes radiologists, medical oncologists, pathologists, and surgeons is paramount for the effective treatment of GIST.

[Gastrointestinal stromal tumors]

Gastrointestinal stromal tumors (GIST) are the most common sarcomas of the gastrointestinal tract. They affect all segments of the digestive tract. They develop from the interstitial cells of Cajal. Mutations in the Kit gene is present in 86% of cases and in PDGFR gene in 15% of cases. The marker CD 117 is present in 95% of cases. Surgery is the standard treatment in localized forms. The tyrosine kinase inhibitor, imatinib is standard in first-line metastatic gastrointestinal stromal tumors, as well as adjuvant treatment after surgery. Sunitinib is the standard in second line.

Acute abdomen caused by nontraumatic hemoperitoneum is the first manifestation of gastric low grade stromal tumor

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract in adults. We treated surgically a man with acute abdomen caused by non-traumatic hemoperitoneum and diagnosed by low grade gastric GIST.

METHODS

A 51-year-old Caucasian man came to the hospital for abdominal pain for 3 hours. He had no history of abdominal trauma. On admission, he was conscious and alert, and he had hypotension (80/50 mmHg) and moderate tachycardia. Abdominal ultrasonography showed the presence of free peritoneal fluid. Abdominal magnetic resonance imaging (MRI) showed diffuse intraabdominal hemorrhage and solid mass lesion at the greater curvature of the stomach. At an emergency laparotomy, a pedunculated, fragile mass of 5×6 cm originating from the posterior wall of the stomach was seen. The tumor was resected. Histopathologically a gastrointestinal stromal tumor was detected.

RESULTS

The patient had an uneventful postoperative course and was discharged on the sixth postoperative day. Follow-up showed no recurrence of the tumor 8 months after surgery.

CONCLUSION

Intraabdominal bleeding is a rare presentation of gastrointestinal stromal tumors. The diagnosis of the tumor should be based on whether sudden abdominal pain occurs in patients with an intraabdominal mass.

Recurrence Risk after Resection of Gastrointestinal Stromal Tumors: Size is Not All that Matters… the Consequences of Tumor Rupture

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that most commonly have activating mutations in KIT. Recurrence after complete resection remains a significant problem, and the ability to identify patients at high risk for recurrence would allow for selective use of adjuvant therapies such as imatinib in patients who may garner the most benefit. Initial staging systems stratified recurrence risk by tumor size and mitotic index, whereas subsequent staging systems also included tumor location. However, other clinical factors may influence prognosis and the risk for tumor recurrence after surgery. The purpose of this article is to highlight tumor rupture as an additional risk factor that should be considered when assessing for recurrence risk. Tumor rupture is associated with decreased survival and increased recurrence rates, but it is not universally included in current staging systems. Patients with ruptured GISTs may not meet the risk criteria elaborated in some current staging systems, yet these patients are at high risk for tumor recurrence and may benefit from adjuvant imatinib therapy. A fundamental understanding of all the risk factors for tumor recurrence, including tumor rupture, and appropriate consideration for adjuvant therapy through a multidisciplinary approach are requisite for the maximal prevention of disease recurrence.

Extraabdominal lymph node metastasis in gastrointestinal stromal tumors (GIST)

BACKGROUND

The two principal ways of metastases in gastrointestinal stromal tumors (GISTs) are diffuse intraabdominal spread and liver metastasis whereas lymph node metastases (LNM) are extremely rare. Accordingly, nodal dissection is generally not recommended for GISTs' surgical treatment.

METHODS

We present two unique cases of GIST with synchronous and metachronous extraabdominal LNM, whose clinical, macro-/microscopic, and immunohistochemical criteria, surgical and neo- or adjuvant therapy were investigated in retrospective analysis.

RESULTS

A 76-year-old man was presented with an inguinal mass and a simultaneously detected intraabdominal mass. Pathological evaluation of the core needle biopsy from the inguinal lymph node confirmed metastatic GIST. Partial resection of the ileum and inguinal lymph node dissection (LND) showed a spindle cell GIST in the ileum with inguinal LNM. Imatinib mesylate therapy was administered, which was interrupted 2 years later because of patient's intolerance. A 35-year-old man underwent extended gastrectomy, atypical liver resection, splenectomy, and LND because of a huge gastric fundus GIST. Postoperative imatinib mesylate therapy was administered. Histology showed multiple regional lymph node metastasis. Two years later, a left hemihepatectomy was performed for liver metastases. During follow-up, new axillary LNM were detected, and a sunitinib therapy was initiated. Thereafter, he developed progressive axillary, mediastinal, hepatic, abdominal, osseous, and cutaneous metastases, and he was treated by palliative cytoreductive surgery.

CONCLUSION

These two cases demonstrate that extraabdominal node metastasis may rarely occur in GIST, either initially or in the setting of widespread disease. In selected cases with confirmed or suspected LNM, LND should be considered. Metachronous extraabdominal lymph node metastasis represents a late event in high-risk GISTs and cannot be controlled by drug therapy alone.

Adjuvant imatinib for gastrointestinal stromal tumors: the current situation and problems

OBJECTIVE

To review the current situation and find out the current problems of adjuvant imatinib for gastrointestinal stromal tumors (GISTs).

METHODS

Searching for articles and records about imatinib for GISTs, especially adjuvant imatinib for GISTs, on MEDLINE, EMBASE and international conference on gastrointestinal.

RESULTS

GISTs are derived from mesenchymal cells of the gastrointestinal tract. The standard treatment for primary GISTs is to resect the tumor together with the negative margins completely without tumor rupture and spillage. Conventional chemotherapy and radiotherapy is ineffective for advanced GISTs. The introduction of imatinib has dramatically changed the natural history of advanced GISTs. Imatinib is generally safe and effective with doses of 400, 600 or 800 mg daily, and has become the standard drug in the treatment for patients with advanced GISTs. Furthermore, most of the toxicity of imatinib is minimal and manageable, almost no treatment-related deaths have been reported. Therefore, adjuvant imatinib therapy is safe and seems to improve recurrence-free survival after the resection of primary GISTs.

CONCLUSIONS

Although U.S Food and Drug Administration and European Medicines Agency have approved the use of adjuvant imatinib for GISTs postoperatively, a series of questions about the use of adjuvant imatinib still exist, such as the impact of adjuvant imatinib on overall survival, the optimal dose, the best duration of treatment and the most suitable patients. Doctors and patients should weigh the pros (the decrease of relapse) and cons (drug toxicity and drug costs), especially in terms of the benefit of overall survival.

Colorectal gastrointestinal stromal tumor

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm arising in the digestive tract, with an estimated prevalence of 15-20 per 1,000,000. GISTs are related to the interstitial cells of Cajal and are characterized by constitutive over-expression of the transmembrane tyrosine kinase receptor KIT. This is produced by a patognomonic mutation of the proto-oncogene c-kit that occurs in up to 90% of cases. Exon 11 is affected most frequently; exons 9 and 13 are less commonly involved. One-third of GISTs lacking KIT mutations exhibits alternative activating mutations in the PDGFRα gene. Colorectal GISTs represent about 5-10% of the cases, mainly located in the rectum that is the third common site. Benign GISTs are more common, but many tumors are of uncertain malignant potential; tumor size and rate of mitosis are still the most reliable criteria for assessing the risk of an aggressive behavior. Surgery is the first-line treatment for resectable non-metastatic colorectal GIST. Standard oncologic resection is inappropriate because skip metastases and lymphatic spread are rarely reported. Segmental colectomy with negative margins is recommended, and local excision is oncologically adequate in highly selected rectal tumors. Radical surgery alone is not always curative especially in high-risk GISTs, and half of patients develops local recurrences or distant metastases after R0 operation. Medical therapeutic strategies have rapidly evolved after the introduction of targeted molecular therapy. Efficacy and safety of imatinib mesylate was first demonstrated in patients with metastatic and unresectable disease. Adjuvant and neoadjuvant use of imatinib are promising therapeutic options to improve the outcome of surgery to downstage unresectable lesions and to allow less extensive resections.

Clinical utility of the new American Joint Committee on Cancer staging system for gastrointestinal stromal tumors: current overall survival after primary tumor resection

BACKGROUND

The objectives of the current study were to assess the reliability of the new revision of the American Joint Committee on Cancer (AJCC) staging system for gastrointestinal stromal tumors (GISTs) based on the National Comprehensive Cancer Network-Armed Forces Institute of Pathology risk classification and to analyze the factors that influence after resection for primary GISTs in 2 AJCC groups: patients with GISTs originating from the stomach and omentum (G-GISTs) and patients with other primary GISTs located mainly in the small bowel (nongastric GISTs [NG-GISTs]).

METHODS

The authors prospectively analyzed a group of 640 patients with primary, CD117-positive GISTs who underwent surgery with curative intention (R0/R1 resection), including 340 G-GISTs (55.5%) and 300 NG-GISTs (44.5%). Factors were explored that had an effect on disease-free survival time (DFS), which was calculated from the date of radical operation to the date of recurrence or last follow-up. The median follow-up was 39 months.

RESULTS

Compared with NG-GISTs, G-GISTs were characterized by a significantly lower median size (5.3 cm and 8.5 cm, respectively; P < .0001) and lower mitotic activity (median, 3 in 50 high-power fields [HPF] vs 5 in 50 HPF; P < .0001), and they were diagnosed in older patients (median age, 62 years vs 57 years; P = .002). The most commonly detected mutations in G-GIST were those located in KIT exon 11 (60.5%) and platelet-derived growth factor receptor alpha (PDGFRA) exon 18 (19%) versus KIT exons 11 and 9 in NG-GISTs (72% and 17.4%, respectively). The prognosis of patients who had G-GISTs was significantly better compared that of patients who had NG-GISTs, with 5-year DFS rates of 69% (median, 83 months) versus 43% (median, 33 months), respectively (P < .00001). The most significant prognostic factors that correlated with shorter DFS in both G-GISTs and NG-GISTs were primary tumor size >5 cm and >10 cm (P < .0001) and mitotic index >5 in 50 HPF and >10 in 50 HPF (P < .0001). The 5-year DFS rates in G-GISTs according to AJCC stage categories were as follows: 96% for stage IA tumors, 92% for stage IB tumors, 51% for II tumors, 22% for stage IIIA tumors, and 22% for stage IIIB tumors (P < .0001). The 5-year DFS rates in NG-GISTs according to AJCC categories were as follows: 92% for stage I tumors, 66% for stage II tumors, 28% for IIIA tumors, and 16% for IIIB tumors (P < .0001). The high prognostic significance of the AJCC classification also was confirmed for overall survival data, including the impact of therapy with tyrosine kinase inhibitors.

CONCLUSIONS

The reliability of AJCC risk classification after resection of primary GIST was confirmed for DFS and overall survival. Patients with primary G-GISTs had a better prognosis than patients with NG-GISTs. In both groups, primary tumor size and mitotic activity were the most important prognostic factors in terms of DFS.

Gastrointestinal stromal tumors: correlation between symptoms at presentation, tumor location and prognostic factors in 47 consecutive patients

Background

Gastrointestinal stromal tumors (GIST) are mesenchymal tumors of the gastrointestinal tract, usually kit-positive, that are believed to originate from interstitial cell of Cajal, or their related stem cells. The most common clinical presentation of these tumors is gastrointestinal bleeding, otherwise they may cause intestinal obstruction, abdominal pain, a palpable mass, or can be incidentally detected during surgery or endoscopic/radiological procedures. Prognosis is related to the size of the tumor and to the mitotic rate; other prognostic factors are tumor location, tumor resection margins, tumor rupture, and c-kit mutation that may interfere with molecular target therapy efficacy.

Aim

Primary aim of this study was to report our experience regarding GIST patients, correlating symptoms at presentation with tumor localization and risk factors.

Patients and methods

47 consecutive patients undergone to surgical resection for GISTs were enrolled in a prospective study from December 1999 to March 2009. Patient's clinical and pathological features were collected and analysed.

Results

The most common symptom was abdominal pain. Bleeding in the digestive tract and abdominal pain were more frequent in gastric GISTs (58% and 61%); acute abdominal symptoms were more frequent in jejunal and ileal GISTs (40% and 60%), p < 0.05. We reported a mild correlation between the mitotic rate index and symptoms at presentation (p 0.074): this correlation was stronger if GISTs causing "acute abdominal symptoms" were compared with GISTs causing "abdominal pain" as main symptom (p 0.039) and with "incidental" GISTs (p 0.022).

We observed an higher prevalence of symptomatic patients in the "high risk/malignant group" of both the Fletcher's and Miettines's classification (p < 0.05).

Conclusion

According with our findings symptoms correlate to tumor location, to class risk criteria as mitotic index and risk classifications, however we cannot conclude that symptoms are per se predictive of survival or patient's outcome.

Gastrointestinal stromal tumors (GISTs): an updated experience

BACKGROUND

Gastrointestinal stromal tumors (GISTs) are relatively common mesenchymal tumors of the digestive tract characterized by c-KIT mutations. This is a comprehensive review of the current data of the literature on the various aspects of the diagnosis and treatment of these tumors.

METHODS

The stomach is the most commonly involved site for these tumors in the digestive tract. Computed tomography and endoscopy can usually establish the diagnosis. The study of certain specific immunohistochemical markers may contribute to better characterization of these tumors.

RESULTS

Surgical resection of GISTs has been the most effective therapy. In addition, targeted therapy with tyrosine kinase inhibitors may reduce the development of recurrence or decrease the disease progression in patients with metastatic disease.

CONCLUSIONS

The introduction of tyrosine kinase inhibitors has resulted in significant improvement in the overall prognosis of these patients. Furthermore, preoperative imatinib can decrease tumor volume and is associated with complete surgical resection in locally advanced primary GISTs.

Tumor expression of B7-H4 predicts poor survival of patients suffering from gastric cancer

To establish the prognostic value of B7-H4 expression by tumor cells in gastric cancer patients, we evaluated the association of B7-H4 expression with clinicopathologic factors and overall survival of gastric cancer patients. A retrospective cohort study including 156 gastric cancer patients was performed in the present report. Immunohistochemical assay was used to evaluate the expression of B7-H4 in the surgical specimens of gastric cancer tissues. Multi-univariate COX model was then used to evaluate the association of B7-H4 expression with the patients' survival and clinicopathological parameters. B7-H4 expression in the gastric cancer cells was observed in about 44.9% gastric cancer specimens. Univariate analysis demonstrated that there was no correlation between B7-H4 expression and sex, age, histological type, pathological grade or tumor size. In contrast, B7-H4 expression correlated positively with cancer invasiveness and lymph node metastasis. In addition, the median overall survival time of patients with lower B7-H4 expression was 13 months longer than that of patients with higher expression (chi(2) = 12.38, P < 0.0001), and the median disease-free survival time of patients with lower B7-H4 expression was significantly longer than that of patients with higher expression (33 vs. 16 months, chi(2) = 14.977, P < 0.0001). After adjustment for other confounding factors, the COX model analysis indicated that the death risk was significantly higher in patients with higher B7-H4 expression than those with lower expression (RR = 1.85, 95% CI = 1.15-2.96). The present study demonstrated that higher B7-H4 expression in cancer cells was associated with poor prognosis of gastric cancer patients. This is consistent with the idea that B7-H4 promotes cancer progression, likely via inhibition of anti-tumor immune responses.

Clinicopathological features of primary jejunoileal tumors

Purpose

Tumors of the small bowel are rare, accounting for about 3-6% of all gastrointestinal neoplasms, though they cover more than 90% of the intestinal surface. However, diagnosis and treatment are difficult and present an ongoing challenge for both gastrointestinal surgeons and gastroenterologists. The aim of this study was to investigate the clinical features of small bowel tumors.

Methods

Between November 1994 and November 2007, 81 patients underwent treatments for primary tumors in the jejuno-ileal region at the Department of Surgery, Kangnam St. Mary's Hospital, the Catholic University of Korea. A retrospective review of the patients' characteristics and variable tumor factors was performed.

Results

The mean age of the patients was 53.2 years with 48 men and 33 women. The most common symptom was abdominal pain (59.3%), followed by bleeding (22.2%) and an abdominal mass (6.2%). We found that the patients with ileal tumors complained mainly of abdominal pain (72.9%) whereas the patients with jejunal tumors presented with gastrointestinal bleeding (36.4%) (P = 0.048). Seventy-six of the 81 patients (93.8%) had malignant tumors, including 40 (49.4%) gastrointestinal stromal tumors, 26 (32.1%) lymphomas and 5 (6.2%) adenocarcinomas. No postoperative mortalities were observed. The overall 5-year survival rate of the patients with malignant small bowel tumors was 31.8%.

Conclusion

Because the clinical features of a primary tumor of the small bowel are obscure and its diagnosis is difficult, maintaining a high degree of suspicion and recognizing the possibility of a primary small bowel tumor are important.

Gastrointestinal stromal tumor (GIST) recurrence following surgery: review of the clinical utility of imatinib treatment

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the gastrointestinal tract. Surgery with complete removal of the tumor is the primary treatment for resectable GIST and the only chance of cure. However, recurrence after surgery is common. The 2 main prognostic factors are the mitotic activity and the size of the tumor. Tumor rupture is also a risk factor for postoperative recurrence, and extra care should be taken while manipulating this soft and friable tumor. Imatinib mesylate (IM, Gleevec(®), Novartis, Basel, Switzerland) is a tyrosine kinase inhibitor and was first studied in the palliative setting for metastatic GIST patients in the year 2000. It is now the cornerstone of metastatic GIST treatment. IM also plays an important role as an adjuvant treatment for resectable GIST and has been shown to increase the recurrence-free survival in phase III studies. However, some points remain to be clarified. Notably, the ideal duration of adjuvant IM after surgery is still unclear. It is also difficult to determine the exact place of surgery in metastatic or recurrent GIST patients in the IM era. A multidisciplinary approach is, therefore, mandatory to offer GIST patients the best treatment available.

Gastrointestinal stromal tumors (GIST): a prospective evaluation of risk factors and prognostic scores

INTRODUCTION

Many risk scores for malignancy in gastrointestinal stromal tumors (GISTs) are based on the combination of size, mitotic index, and location in order to predict recurrence, appearance of metastases, or survival.

DESIGN

This is a prospective analysis of prognosis factors (size, mitotic index, Ki-67, and others) and malignancy risk scores (Fletcher's, modified NIH, Miettinen, NCCN, and A or B Goh's scores). This is a study of the sensitivity and specificity of the different malignancy risk scores in the prognosis of recurrence and survival.

MATERIALS AND METHODS

We operated on 52 patients from 1 January 2002 to 10 January 2008. Mean follow-up was 35 months. We used SPSS 13.0 for Windows for the statistical analysis. The differences between frequencies and means were calculated using the chi-square test, Student's t test, and analysis of variance. Kaplan-Meier and the Cox multiple regression methods were used to calculate overall and disease-free survival. Sensitivity and specificity were depicted graphically as receiver operating characteristic (ROC) curves.

RESULTS

Thirteen patients suffered recurrences (27.7%). Eleven died from disease-related causes. Two-year and 5-year actuarial survival was 80% and 76%, respectively, and the mean survival was 60 months (CI 95% 51.9-69.5). Two-year and 5-year actuarial disease-free survival was 76% and 72% respectively, and the mean disease-free survival was 52 months (CI 95% 43.5-61.1). The score proposed by Fletcher has the greatest sensitivity and specificity in our series to predict overall survival (AUROC = 0.761; SE 0.084, p = 0.009; CI 95% 0.597-0.926) and recurrence (AUROC RECURRENCE = 0.693; SE 0.087, p = 0.042; CI 95% 0.523-0.864) compared with other scores.

Segmental duodenectomy for gastrointestinal stromal tumor of the duodenum

AIM: To evaluate the results of segmental duodenectomy (SD) and pancreaticoduodenectomy (PD) for duodenal gastrointestinal stromal tumor (GIST) and help clinicians with surgical management.

METHODS: All patients who underwent surgery for non-metastatic GIST of the duodenum in a single institution since 2000 were prospectively followed up. Seven patients (median age 51 years, range: 41-73 years) were enrolled: five underwent SD and two underwent PD.

RESULTS: All the patients had a complete resection (R0), with no postoperative morbidity and mortality. Among the SD group, GIST was classified as low risk in two patients, intermediate risk in two, and high risk in one, according to the Fletcher scale, (vs two high risk patients in the PD group). With a median follow-up of 41 (18-85) mo, disease-free survival (DFS) rates were 100% after SD and 0% after PD (P < 0.05). The median DFS was 13 mo in the PD group.

CONCLUSION: Whenever associated with clear surgical margins, SD is a reliable and curative option for most duodenal GISTs, and is compatible with long-term DFS.

[Controversies in the surgical treatment of primary gastrointestinal stromal tumours (GIST)]

It is estimated that 50% of GIST are located at the time of their diagnosis. A complete surgical resection can be performed in up to 95% of these cases, making this the most important prognostic factor. This surgery must fulfil a series of technical requirements so as to be really effective, as it has to be R0, with no tumour rupture, with preservation of the pseudo-capsule, etc. Although the majority of GIST are gastric, their location in other anatomical areas, such as the oesophagus, duodenum or rectum, require the surgeon to use more complex techniques. Laparoscopy is increasingly used; however, we must avoid its use, due to there being few experienced groups or if there are large tumours. The use of neoadjuvant therapy has revived great interest by allowing to resection tumours that were once non-resectable or in very compromised anatomical locations, with less aggressive surgery. The use of pre-surgical biopsy is not exempt from serious risks, thus it should only be used for establishing a neoadjuvant treatment or if there are diagnostic doubts with other diseases in high risk patients.

Gastrointestinal stromal tumor of stomach with inguinal lymph nodes metastasis: A case report

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor in the alimentary tract. To the best of our knowledge, few cases have been reported in the literature about the peripheral lymph node metastasis of GIST. Here we report an unusual case of gastric GIST with inguinal lymph nodes metastasis. After the metastatic lymph nodes were resected, the. patient started to take imatinib 400 mg/d for 12 mo. There were no signs of tumor recurrence at follow-up after 29 mo. This case suggests that the inguinal lymph nodes can be a potential metastatic site of GIST.