Gastrointestinal stromal tumours (GIST) – 17 years experience from Mid Trent Region (United Kingdom)

Ruptured Duodenal GIST in a Young Female - A Rare Presentation and Comprehensive Review

Gastrointestinal stromal tumors (GISTs) are uncommon mesenchymal neoplasms primarily found in the gastrointestinal (GI) tract. While they typically occur in older adults, GISTs can manifest in individuals of any age. This publication paper presents a case study of a rare occurrence: a spontaneously ruptured duodenal GIST in a young female. Through an in-depth review of the literature, we aim to provide insights into the clinical presentation, diagnostic challenges, management strategies, and long-term outcomes associated with this unique clinical scenario.

Gastrointestinal Stromal Tumor: A Clinicopathological Study and Management

Background and aim Gastrointestinal stromal tumors (GISTs) account for a major portion of gastrointestinal mesenchymal tumors. The purpose of the current study is to examine the clinicopathological features, management, and therapeutic outcomes of primary GIST in a tertiary care hospital.  Materials and methods This is a prospective observational analysis. Seventeen patients with GIST have been detected and treated in the Department of Surgery of a tertiary care hospital with an attached medical institution over the last seven years. The clinical presentation, diagnosis method, tumor locations, histopathological results, surgical treatment, and postoperative results were analyzed.  Results There were six females and 11 males with ages ranging between 35 to 72 years. All the patients had symptoms, with abdominal pain the most prevalent. The most frequent primary site for GIST was the stomach (60-70%), followed by the small intestine (25-30%), the rectum, the esophagus, and the colon (2%). Preoperative diagnosis was made through endoscopy and a contrast-enhanced CT scan. Ninety-two percent of the cases tested positive for CD117. Surgery has been conducted for all 17 patients, with the liver being the most common site of metastasis. Imatinib and sunitinib increased the survival as well as postoperative recurrence rate while decreasing metastasis.  Conclusions The most general symptom of GIST was abdominal pain. In most instances, it was treated with surgery as well as adjuvant imatinib and sunitinib, and had a favorable prognosis. With increasing size and mitotic activity, the five-year survival rate falls, and the prognosis worsens.

An Unexpected GIST Causing Life-Threatening Bleeding after an Elective Hernia Repair

Background  Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the alimentary tract. They are usually manifested by GI bleeding. Case Presentation  A 53-year-old male patient was admitted to the hospital for elective inguinal hernia repair. The patient did not have any history of GI symptoms in the past. A day after open inguinal hernia repair, the patient developed recurrent attacks of hematemesis resulting in hemodynamic instability and admission to the intensive care unit. An upper GI endoscopy identified a small bleeding gastric lesion. After multiple failed attempts to control the bleeding endoscopically, an emergency exploratory laparotomy was performed. An unexpected large fungating bleeding gastric mass was detected. The mass measured approximately 40 × 30 cm, and multiple peritoneal deposits were also discovered. A wedge resection of the anterior gastric wall along with the mass was performed. Histopathology revealed a high-grade (G2) GIST. Discussion  GISTs appear in variable sizes and may lead to a variety of complications including abdominal pain, GI obstruction, and bleeding. This case highlights the unexpected presentation and sudden bleeding of a large GIST in a totally asymptomatic patient undergoing elective hernia surgery. It also illustrates that GIST can be asymptomatic and grow to large sizes before developing clinical manifestations. Conclusion  The case report highlights a common complication of GIST with unexpected timing, immediately after routine hernia surgery.

Safety and feasibility of laparoscopy-assisted surgery for gastrointestinal stromal tumors larger than 5 cm: Results of a retrospective, single-center series of 1,802 consecutive patients

BACKGROUND

The role of laparoscopy-assisted resection for treating gastrointestinal stromal tumors >5 cm is still disputed. We aimed to assess the advantages of laparoscopy-assisted resection for treating gastrointestinal stromal tumors >5 cm.

METHODS

In total, 1,802 patients with primary gastrointestinal stromal tumors who underwent laparoscopy-assisted surgery or open surgery were retrospectively evaluated. Propensity score matching was performed to reduce confounders.

RESULTS

In total, 518 patients with tumor size >5 cm were enrolled in this study (males: 292, 56.4%; females: 226, 43.6%; median age: 58 years, range: 23-85 years). One hundred and twenty-three (23.7%) patients underwent laparoscopy-assisted resection, and 395 (76.3%) patients underwent open resection. After propensity score matching, 190 patients were included (95 in each group). The laparoscopy-assisted surgery group was superior to the open surgery group considering the blood loss (>200 mL: 6.3% vs 22.1%, P = .005), length of midline incision (6.0 ± 0.9 cm vs 9.6 ± 2.1 cm, P < .001), time to first flatus (49.7 ± 10.5 hours vs 63.9 ± 7.4 hours, P < .001), and shorter hospital stay (10.3 ± 3.2 days vs 11.9 ± 2.9 days, P < .001). The difference in relapse-free survival or overall survival between the laparoscopy-assisted surgery and open surgery groups after matching was not significant (all P > .05). On subgroup analysis, the relapse-free survival and overall survival of the laparoscopy-assisted surgery group were comparable to those of the open surgery group, irrespective of tumor location (gastric or nongastric locations) (all P > .05).

CONCLUSION

When performed by experienced surgeons, laparoscopy-assisted resection is feasible and safe for gastrointestinal stromal tumors >5 cm, which showed improved short-term outcomes and comparable oncological outcomes, regardless of whether the tumor had a gastric or nongastric location.

Incidence of gastrointestinal stromal tumor in Chinese urban population: A national population-based study

BACKGROUND

Information on incidence of gastrointestinal stromal tumor (GIST), the most common type of mesenchymal tumor in gastrointestinal tract, was limited in China. This study aimed to estimate the incidence of GIST in urban population from mainland China in 2016.

METHODS

Urban Employee Basic Medical Insurance (UEBMI) and Urban Residence Basic Medical Insurance (URBMI) in China were used. The denominator of incidence was the total person-years of insured individuals in 2016 in the database, covering approximately 0.43 billion individuals. The numerator was the number of incident GIST cases in 2016.

RESULTS

The crude incidence in 2016 was 0.40 per 100,000 person-years (95% CI, 0.06-1.03). Male incidence was higher than female incidence (0.44 vs. 0.36, rate ratio: 1.22, p < 0.001). The mean age at diagnosis was 55.20 years (SD = 14.26) and the incidence among those aged 50 years or older was 2.63 times (0.84 vs. 0.32, p < 0.001) higher than those aged under 50. The highest incidence was observed in East China (2.29, 95% CI: 0.46-5.54).

CONCLUSIONS

The incidence of GIST in mainland China was lower than Europe, North America and Korea. The mean age at diagnosis of GIST in China was younger than that of Europe and Canada. This study provides useful information to further research, policy formulating and management of GIST.

Quality of Surgery and Outcome in Localized Gastrointestinal Stromal Tumors Treated Within an International Intergroup Randomized Clinical Trial of Adjuvant Imatinib

Importance

The association between quality of surgery and overall survival in patients affected by localized gastrointestinal stromal tumors (GIST) is not completely understood.

Objective

To assess the risk of death with and without imatinib according to microscopic margins status (R0/R1) using data from a randomized study on adjuvant imatinib.

Design, Setting, and Participants

This is a post hoc observational study on patients included in the randomized, open-label, phase III trial, performed between December 2004 and October 2008. Median follow-up was 9.1 years (IQR, 8-10 years). The study was performed at 112 hospitals in 12 countries. Inclusion criteria were diagnosis of primary GIST, with intermediate or high risk of relapse; no evidence of residual disease after surgery; older than 18 years; and no prior malignancies or concurrent severe/uncontrolled medical conditions. Data were analyzed between July 17, 2017, and March 1, 2020.

Interventions

Patients were randomized after surgery to either receive imatinib (400 mg/d) for 2 years or no adjuvant treatment. Randomization was stratified by center, risk category (high vs intermediate), tumor site (gastric vs other), and quality of surgery (R0 vs R1). Tumor rupture was included in the R1 category but also analyzed separately.

Main Outcomes and Measures

Primary end point of this substudy was overall survival (OS), estimated using Kaplan-Meier method and compared between R0/R1 using Cox models adjusted for treatment and stratification factors.

Results

A total of 908 patients were included; 51.4% were men (465) and 48.6% were women (440), and the median age was 59 years (range, 18-89 years). One hundred sixty-two (17.8%) had an R1 resection, and 97 of 162 (59.9%) had tumor rupture. There was a significant difference in OS for patients undergoing an R1 vs R0 resection, overall (hazard ratio [HR], 2.05; 95% CI, 1.45-2.89) and by treatment arm (HR, 2.65; 95% CI, 1.37-3.75 with adjuvant imatinib and HR, 1.86; 95% CI, 1.16-2.99 without adjuvant imatinib). When tumor rupture was excluded, this difference in OS between R1 and R0 resections disappeared (HR, 1.05; 95% CI, 0.54-2.01).

Conclusions and Relevance

The difference in OS by quality of surgery with or without imatinib was associated with the presence of tumor rupture. When the latter was excluded, the presence of R1 margins was not associated with worse OS.

Trial Registration

ClinicalTrials.gov Identifier: NCT00103168.

Surgical treatment of primary gastrointestinal stromal tumors (GISTs): Management and prognostic role of R1 resections

BACKGROUND

Surgery represents the best treatment for primary gastrointestinal stromal tumors (GISTs). The aim of this study is to analyse outcomes of surgical management in order to evaluate the influence of microscopically R1 margins on survival and recurrence in patients affected by GISTs.

METHODS

The study reviewed retrospective data from 74 patients surgically treated for primary GISTs without metastasis at diagnosis. Clinical and pathological findings, surgical procedures, information about follow up and outcomes were analyzed.

RESULTS

Recurrence rate was low and no patients died in the R1 group during the follow up period. The difference in recurrence free survival for patients undergoing an R0 (n = 54) versus an R1 (n = 20) resections was not statistically significant (76% versus 85% at 3 years, logrank test p-value = 0,14; 63% versus 86% at 5 years, logrank test p-value = 0,48) CONCLUSIONS: Microscopically positive margin has no influence on overall and relapse-free survival in GIST patients. Thus, when R0 surgery implies major functional sequelae, it may be decided to accept possible R1 margins, especially for low risk tumors.

Relationship between R1 resection, tumour rupture and recurrence in resected gastrointestinal stromal tumour

Background

According to guidelines, adjuvant treatment or re-excision should be considered after R1 resection of gastrointestinal stromal tumours (GISTs). However, the prognostic significance of R1 resection is uncertain and tumour rupture confounds its assessment. Here, the impact of positive margins was examined and related to rupture in a population-based cohort.

Methods

Patients undergoing surgery for non-metastatic GIST since 2000 were identified in the sarcoma database of Oslo University Hospital. Margins were coded according to the residual tumour (R) classification and tumour rupture defined according to the Oslo criteria.

Results

Among 410 patients, there were 47 who underwent R1 resection and 52 had tumour rupture. The relative risk of R1 resection with rupture was 3·55 (95 per cent c.i. 2·09 to 6·03; P &lt; 0·001). In patients without rupture, there was no difference in estimated 5-year recurrence-free survival after R0 versus R1 resection (87·6 versus 93 per cent; hazard ratio (HR) 0·71, 95 per cent c.i. 0·17 to 2·98; P = 0·638); nor was there any difference among patients with rupture (37 versus 31 per cent; HR 1·31, 0·68 to 2·54; P = 0·420). In multivariable analysis, tumour rupture but not R1 resection was independently associated with recurrence. Twenty-four patients at very low, low or intermediate risk did not receive adjuvant imatinib after R1 resection and remained recurrence-free.

Conclusion

Positive resection margins are strongly associated with tumour rupture. R1 resection does not independently influence prognosis. Adjuvant imatinib may not be justified after R1 resection in the absence of tumour rupture or other high-risk features.

Gastrointestinal stromal tumor: clinicopathological characteristics and pathologic prognostic analysis

Objective

This study aimed to understand clinicopathological characteristics of gastrointestinal stromal tumors (GISTs) and correlation between pathologic features and clinical outcome.

Methods

We used 76 cases diagnosed as primary GISTs during January 2007 to July 2017 at Army Institute of Pathology, Thailand. Clinical, survival, and pathological data were collected and analyzed.

Results

Ages of the patients ranged from 15 to 88 years (M:F = 1:1). The most common presentation was gastrointestinal bleeding (39.7%). The most common site was the stomach (64.5%). Tumor size ranged from 0.6 to 25.5 cm (average 8.78 cm). Histologic types were spindle cell type (75%), mixed spindled-epithelioid type (17.1%), and epithelioid type (7.9%). The majority of histologic subtype was diffuse hypercellularity (67.1%). Tumor necrosis was found in 38.1% and 80% showed low mitotic counts. Most gastrointestinal stromal tumors (27.6%) are low-risk category according to Miettinen and Lasota’s algorithm. Metastasis was found in 27.7%, mostly occurs within 2 years, and is correlated with tumor size > 10 cm (P = 0.023), non-spindle cell histologic type (P = 0.027), mitotic count > 5/5mm² (P = 0.000), myxoid change (P = 0.011), and mucosal invasion (P = 0.002). Recurrence was found in 8.1%, mostly occurs within 7 years, and correlated with myxoid change (P = 0.045).

Conclusion

We found that most of GISTs show spindle cell type and low-risk category. Metastasis was correlated with tumor size > 10 cm, non-spindle cell histologic type, mitotic count > 5/5mm², myxoid change, and mucosal invasion. Recurrence was correlated with myxoid change.

Current treatment strategies in pediatric gastrointestinal stromal cell tumor

Gastrointestinal stromal tumors (GIST) are exceedingly rare tumors in the pediatric population. As a result, many clinicians either may never see this diagnosis or will encounter it only a few times throughout their careers. Additionally, the more we discover about this disease, it becomes evident that it represents a distinct clinical entity from adult GIST. Many of the treatments and strategies used to combat the adult tumor are either ineffective or may be harmful to the pediatric population with this disease. The unique tumor biology found in pediatric GIST necessitates unique approaches and treatment strategies in order to achieve the best clinical outcome. This review aims to discuss the most recent data available on the different therapeutic modalities utilized in cases of Pediatric GIST.

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.

Global epidemiology of gastrointestinal stromal tumours (GIST): A systematic review of population-based cohort studies

BACKGROUND

Gastrointestinal stromal tumours (GISTs) are rare, yet the most common mesenchymal tumour within the digestive tract. Lack of diagnostic criteria and no specific code in the ICD system has prevented epidemiological evaluation except from overt malignant cases in the past. A global estimate of incidence and disease patterns has thus not been available.

METHODS

A systematic literature search of all available population-based studies on GIST published between January 2000 and December 2014 were reviewed. Descriptive epidemiological data are presented.

RESULTS

The search found 29 studies of more than 13,550 patients from 19 countries that reported sufficient data for regional or national population-based statistics. Age at diagnosis ranged from 10 to 100 years, with median age being mid 60s across most studies. Gender distribution was equal across studies. On average, 18% of patients had an incidental diagnosis (range from 5% to 40%). Anatomical location of primary tumour in 9747 GISTs demonstrated gastric location as the most frequent (55.6%) followed by small bowel (31.8%), colorectal (6.0%), other/various location (5.5%) and oesophagus (0.7%). Most studies reported incidence at 10-15 per million per year. Notably, lowest incidence was in China (Shanxi province) with 4.3 per million per year. Highest incidence rates were reported also from China (Hong Kong and Shanghai areas), and in Taiwan and Norway (Northern part), with up to 19-22 per million per year.

CONCLUSIONS

Epidemiology of GIST demonstrates some consistent features across geographical regions. Whether the reported extreme differences in incidence reflect real variation in population risk warrants further investigation.

Duodenal gastrointestinal stromal tumor: From clinicopathological features to surgical outcomes

Duodenal gastrointestinal tumors represent an extremely rare subset of stromal tumors arising from interstitial cells of Cajal. In the last 30 years the comprehension of the pathophysiology and natural history of this previously misunderstood clinical entity, in association with developments in endoscopy, imaging technology, and immunohistochemistry has resulted in novel diagnostic and treatment approaches. This is a comprehensive review of the current data of the literature on the various aspects of the diagnosis and treatment of these tumors. The duodenum is the less commonly involved site for these tumors in the digestive tract. Endoscopy and computed tomography can usually establish the diagnosis, confirmed by immunohistochemical staining and occasionally molecular genetic analysis. Endoscopic ultrasound with fine needle aspiration has been recently found to be the gold diagnostic standard with high sensitivity and specificity rates, diagnosing GIST in up to 80% of patients. Due to the complex anatomy of the pancreatico-duodenal region optimal therapeutic strategy of duodenal GISTs are challenging. Nevertheless surgical resection with microscopically clear resection margins seems to be the only potentially curative treatment for non-metastatic primary GISTs of the duodenum. Imatinib mesylate plays a key role in the management of GISTs both as neoadjuvant therapy and in patients with recurrent and metastatic disease. Meanwhile, the advances in the comprehension of the pathophysiology and natural history of this previously misunderstood clinical entity as well as the treatment of these tumors may render feasible, in the near future, the advent of newer and more effective treatment options.

Oesophageal GIST-A rare breed case report and review of the literature

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We present a case of oesophageal gastrointestinal stromal tumour (GIST).

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GISTs in the oesophagus are rare (5%) and their management is surrounded by debate.

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Surgical therapy should aim for complete resection.

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Preoperative biopsies are best to be avoided as they might propagate seeding.

Introduction

Gastrointestinal stromal tumours (GIST) account for only one percent of all gastrointestinal malignancies.

Presentation of case

A 53 year old lady presented to the gastroenterology clinic with iron deficiency anaemia. Oesophagogastroduodenoscopy (OGD) and computed tomography (CT) demonstrated a non-obstructing 7 cm submucosal oesophageal lesion. An oesophagectomy was performed and subsequent histology sections showed a well-circumscribed spindle cell tumour without any cellular atypia. Immunohistochemistry on the tumour was negative for S100 and positive for smooth muscle actin and desmin. C-kit (CD117) showed focal positivity in some of the tumour cells and the overall features were of a gastro-intestinal stromal tumour (GIST).

The patient has been fully compliant with the follow-up arrangements and is disease-free six years after her original operation.

Discussion

GISTs are mesenchymal tumours of the gastrointestinal (GI) tract that express the KIT protein. The incidence rate for GIST is 15 cases to one million in the USA.

GISTs in the oesophagus are rare (5%) and their management is surrounded by some debate.

Once the diagnosis has been secured the patient should be evaluated for suitability for surgical resection.

Optimal surgical therapy should aim to achieve complete resection, if possible, without injury to the pseudocapsule surrounding the tumour. Meticulous atraumatic surgical technique is necessary and preoperative biopsies are best to be avoided as they might propagate seeding.

Conclusions

Oesophagectomy with clear resection margins should be the preferred method for surgical treatment combined with the use of novel TKI strategies.

Validation of the MSKCC Gastrointestinal Stromal Tumor Nomogram and Comparison with Other Prognostication Systems: Single-Institution Experience with 289 Patients

PURPOSE

To validate the Memorial Sloan Kettering Cancer Center (MSKCC) prognostic nomogram in a single-institution cohort of patients with gastrointestinal stromal tumors (GISTs), and to compare its predictive accuracy against other established risk classification systems, including the National Institutes of Health (NIH), Armed Forces Institute of Pathology (AFIP), and Joensuu criteria.

METHODS

We retrospectively reviewed 289 patients who underwent surgical resection for primary localized GISTs without adjuvant imatinib therapy and compared the actuarial recurrence-free survival (RFS) with the predicted RFS.

RESULTS

Tumors >5 cm in size, with high mitotic index, and which had ruptured were significantly associated with recurrent disease. The 2-year RFS was 77.2 % [95 % confidence interval (CI) 71.6-81.8], and the 5-year RFS was 67.9 % (95 % CI 61.7-73.4). The concordance probability of the nomogram of 2-year RFS was 0.71 (SE 0.02), and 5-year RFS was 0.71 (SE 0.19). The 2-year and 5-year MSKCC nomogram probability calculations and the AFIP criteria gave a better estimation of RFS compared to the NIH (p < 0.001) and Joensuu (p < 0.001) criteria. There was no significant difference between the predictive accuracy of the nomogram compared to the AFIP criteria.

CONCLUSIONS

The MSKCC nomogram slightly underestimated the probability of RFS after surgical resection of GISTs. It was associated with a significantly better predictive accuracy compared to the NIH and Joensuu. This study suggests that there is a wider than expected prognostic divergence between gastric GISTs versus GISTs arising from the small intestine.

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.

The epidemiology of gastrointestinal stromal tumors in Taiwan, 1998-2008: a nation-wide cancer registry-based study

Background

To investigate the incidence of gastrointestinal stromal tumors (GISTs) in Taiwan and the impact of imatinib on the overall survival (OS) of GIST patients.

Methods

GISTs were identified from the Taiwan Cancer Registry (TCR) from 1998 to 2008. The age-adjusted incidence rates and the observed OS rates were calculated. Cox proportional hazards models were applied to examine the mortality risk in three time periods (1998–2001, 2002–2004, 2005–2008) according to the application and availability of imatinib.

Results

From 1998 to 2008, 2,986 GISTs were diagnosed in Taiwan. The incidence increased from 1.13 per 100,000 in 1998 to 1.97 per 100,000 in 2008. The most common sites were stomach (47-59%), small intestine (31-38%), and colon/rectum (6-9%). The 5-year observed OS was 66.5% (60.3% for men, 74.2% for women, P < .0001). GISTs in the stomach had a better 5-year observed OS (69.4%) than those in the small intestine (65.1%) (P < .0001). The outcome of GIST improved significantly after the more widespread use of imatinib; the 5-year observed OS increased from 58.9% during 1998–2001 to 70.2% during 2005–2008 (P < .0001). Younger age, female sex, stomach location, and later diagnostic years were independent predictors of a better survival.

Conclusions

The incidence of GIST has been increasing in Taiwan, partially due to the advancement of diagnostic technology/method and the increased awareness by physicians. The outcome of GIST has improved significantly with the availability and the wider use of imatinib.

Microscopically positive margins for primary gastrointestinal stromal tumors: analysis of risk factors and tumor recurrence

BACKGROUND

Little is known about the outcomes of patients with microscopically positive (R1) resections for primary gastrointestinal stromal tumors (GIST) because existing retrospective series contain small numbers of patients. The objective of this study was to analyze factors associated with R1 resection and assess the risk of recurrence with and without imatinib.

STUDY DESIGN

We reviewed operative and pathology reports for 819 patients undergoing resection of primary GIST from the North American branch of the American College of Surgeons Oncology Group (ACOSOG) Z9000 and Z9001 clinical trials at 230 institutions testing adjuvant imatinib after resection of primary GIST. Patient, tumor, operative characteristics, factors associated with R1 resections, and disease status were analyzed.

RESULTS

Seventy-two (8.8%) patients had an R1 resection and were followed for a median of 49 months. Factors associated with R1 resection included tumor size (≥ 10 cm), location (rectum), and tumor rupture. The risk of disease recurrence in R1 patients was driven largely by the presence of tumor rupture. There was no significant difference in recurrence-free survival for patients undergoing an R1 vs R0 resection of GIST with (hazard ratio [HR] 1.095, 95% CI 0.66, 1.82, p = 0.73) or without (HR 1.51, 95% CI 0.76, 2.99, p = 0.24) adjuvant imatinib.

CONCLUSIONS

Approximately 9% of 819 GIST patients had an R1 resection. Significant factors associated with R1 resection include tumor size ≥ 10 cm, location, and rupture. The difference in recurrence-free survival with or without imatinib therapy in those undergoing an R1 vs R0 resection was not statistically significant at a median follow-up of 4 years.

A multi-centre analysis of the impact of updated risk stratification on follow-up of gastric gastro-intestinal stromal tumours in the post-imatinib era

BACKGROUND

Previously Gastro-Intestinal Stromal Tumours (GISTs) have been risk stratified histologically according to their size and mitotic index. However, gastric GISTs have a lower likelihood of recurrence and so the Miettinen criteria are now used to risk stratify patients. Records were reviewed from multiple centres to determine if these changes altered patients' clinical care and also to determine the survival of patients following the introduction of imatinib therapy.

METHODS

Prospective databases of GISTs undergoing surgical resection and those reviewed by the regional sarcoma MDT were cross-referenced and added to by searching a variety of clinical and pathology coding datasets, to identify patients diagnosed between January 2000 and March 2010. Patients undergoing resection for localised disease were re-scored using Miettinen criteria and Kaplan-Meier analysis was used to determine survival outcomes.

RESULTS

The search identified 203 patients; including 132 gastric GISTs, 89 of which had resections of untreated localised disease. These were reassessed, of which approximately one third were scored as intermediate risk. Following reclassification, 26 of 29 of intermediate risk cases moved to low risk groups, representing 27.7% of all those remaining in follow-up at the time of audit. Median survival was not reached after a median follow-up of 3.85 years and 4-year survival was estimated at 72%.

CONCLUSIONS

Clinicians involved in the follow-up of gastric GISTs should reassess the pathology of all intermediate and high risk patients in order to decrease patient exposure to stressful interventions, as well as hospital workload, and expenditure on unnecessary observation.

Risk of recurrence of gastrointestinal stromal tumour after surgery: an analysis of pooled population-based cohorts

BACKGROUND

The risk of recurrence of gastrointestinal stromal tumour (GIST) after surgery needs to be estimated when considering adjuvant systemic therapy. We assessed prognostic factors of patients with operable GIST, to compare widely used risk-stratification schemes and to develop a new method for risk estimation.

METHODS

Population-based cohorts of patients diagnosed with operable GIST, who were not given adjuvant therapy, were identified from the literature. Data from ten series and 2560 patients were pooled. Risk of tumour recurrence was stratified using the National Institute of Health (NIH) consensus criteria, the modified consensus criteria, and the Armed Forces Institute of Pathology (AFIP) criteria. Prognostic factors were examined using proportional hazards and non-linear models. The results were validated in an independent centre-based cohort consisting of 920 patients with GIST.

FINDINGS

Estimated 15-year recurrence-free survival (RFS) after surgery was 59·9% (95% CI 56·2-63·6); few recurrences occurred after the first 10 years of follow-up. Large tumour size, high mitosis count, non-gastric location, presence of rupture, and male sex were independent adverse prognostic factors. In receiver operating characteristics curve analysis of 10-year RFS, the NIH consensus criteria, modified consensus criteria, and AFIP criteria resulted in an area under the curve (AUC) of 0·79 (95% CI 0·76-0·81), 0·78 (0·75-0·80), and 0·82 (0·80-0·85), respectively. The modified consensus criteria identified a single high-risk group. Since tumour size and mitosis count had a non-linear association with the risk of GIST recurrence, novel prognostic contour maps were generated using non-linear modelling of tumour size and mitosis count, and taking into account tumour site and rupture. The non-linear model accurately predicted the risk of recurrence (AUC 0·88, 0·86-0·90).

INTERPRETATION

The risk-stratification schemes assessed identify patients who are likely to be cured by surgery alone. Although the modified NIH classification is the best criteria to identify a single high-risk group for consideration of adjuvant therapy, the prognostic contour maps resulting from non-linear modelling are appropriate for estimation of individualised outcomes.

FUNDING

Academy of Finland, Cancer Society of Finland, Sigrid Juselius Foundation and Helsinki University Research Funds.

Gastrointestinal stromal tumors: Thirty years experience of an Institution

AIM: To report our experience of gastrointestinal stromal tumors (GISTs) during the last 29 years.

METHODS: Thirty two cases of GIST referred to our Institution from the 1st January 1981 to the 10th June 2010 were reviewed. Metastases, recurrence and survival data were collected in relation to age, history, clinical presentation, location, size, resection margins and cellular features.

RESULTS: Mean age was 63.7 years (range, 40-90) and incidence was slightly higher in males (56%). R0 resection was performed in 90.7% of cases, R1 in 6.2% (2 cases) and R2 in 3.1% (one case). Using Fletcher’s classification 8/32 (25%) had high risk, 9/32 (28%) intermediate and 15/32 (47%) low risk tumors. Follow-up varied from 1 mo to 29 years, with a median of 8 years; overall survival was 75% (24/32), disease-free survival was 72% and tumor-related mortality was 9.3%. Three patients with high risk GIST were treated with imatinib mesylate: one developed a recurrence after 36 mo, and 2 are free from disease at 41 mo.

CONCLUSION: Surgical treatment remains the gold standard therapy for resectable GISTs. Pathological and biological features of the neoplasm represent the most important factors predicting the prognosis.

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.

Post-operative imatinib in patients with intermediate or high risk gastrointestinal stromal tumor

AIMS

This study aims to determine whether adjuvant treatment with imatinib improves recurrence-free survival (RFS) in Chinese patients undergoing complete resection of localized primary gastrointestinal stromal tumor (GIST) compared with those not receiving adjuvant therapy. We also sought a correlation between c-KIT mutations and RFS.

METHODS

Patients who had undergone complete tumor resection with intermediate or high risk of recurrence were enrolled in a single-center, non-randomized, prospective study. Patients either received adjuvant imatinib therapy (400 mg once-daily) for 3 years or did not. Mutation analyses of c-KIT were performed on available archival tumor samples.

RESULTS

105 patients were enrolled: 56 in the treatment group and 49 in the control group. Median follow-up was 45(43.1-46.9) months. RFS at 1, 2 and 3 years were higher in the treatment group than in the control group (100% vs. 90% at 1 year; 96% vs. 57% at 2 years; 89% versus 48% at 3 years, P < 0.001, HR = 0.188). Subgroup analyses showed that adjuvant therapy significantly decreased the risk of recurrence in patients whether at high risk or at intermediate risk compared with control patients (3-year RFS: 95% vs. 72%, in intermediate risk; 85% versus 31% in high risk; P < 0.001). In addition, imatinib adjuvant treatment decreased the risk of death (P = 0.025, [corrected] HR = 0.254).

CONCLUSIONS

Adjuvant imatinib can improve 1-, 2- and 3-year RFS rates in patients at intermediate or high risk of recurrence after complete tumor resection.

CLINICAL TRIALS REGISTRATION NUMBER

ChiCTR-TCC-00000582.

Navigating risk stratification systems for the management of patients with GIST

BACKGROUND

The central drivers of the aberrant behavior of gastrointestinal stromal tumors (GIST) are constitutively activated forms of stem-cell receptor factor, and, to a lesser extent, platelet-derived growth factor receptor alpha. Standard treatment for primary, localized GIST is surgical resection. Risk stratification systems assist in determining the risk of disease recurrence in individual patients with GIST, so disease management can be personalized.

METHODS

In May 2010, a literature review of the PubMed database was conducted to identify articles pertaining to prognostic factors and risk stratification systems for GIST. Key results from these studies were analyzed.

RESULTS

The first widely accepted risk stratification system for GIST, the National Institutes of Health consensus classification system, stratified patients into risk groups on the basis of tumor size and mitotic index. Tumor location (i.e., stomach or intestine) was subsequently shown to have independent prognostic value and was incorporated into the Miettinen-Lasota/Armed Forces Institute of Pathology risk stratification system. Tumor size, location, and mitotic index remain the main variables used in risk stratification systems. Other variables such as tumor rupture and GIST genotype have recently been shown to have prognostic value. As an alternative to stratification into discrete groups, nomograms present risk of recurrence as percentages on a continuous scale. Improved use of existing prognostic variables and routine incorporation of additional variables (e.g., GIST genotype) will further refine risk stratification systems.

CONCLUSIONS

Refinement of risk stratification systems will increase the precision of these systems for predicting recurrence, which may facilitate improvements in individual disease management.

Gastrointestinal stromal tumors: a clinicopathological and immunohistochemical study of 121 cases

BACKGROUND

Primary mesenchymal tumors of the gastrointestinal tract are a heterogeneous group of tumors with a wide clinical spectrum, of which gastrointestinal stromal tumors (GIST) typically occur in middle-aged to older individuals. This study evaluated the clinicopathological and morphological features of GIST of the intestinal tract.

METHODS

The study included 108 gastrointestinal and 13 extra-gastrointestinal stromal tumors involving the mesentry and retroperitoneum between January 1989 and July 2007. Immunohistochemical expression of CD117, CD34, SMA, Desmin, S100, and Ki-67 were studied.

RESULTS

GIST comprised 108 of 120 (90%) of the mesenchymal tumors. The tumor was located in the stomach in the majority (55%) of patients followed by small intestine (30%), retroperitoneum (7%) and the colorectum (4%). There was a significant correlation between tumor size and mitotic index, with larger tumors having higher mitotic index (p < 0.001). Mitotic index per 5 mm(2) correlated with high cellularity (p < 0.001), presence of necrosis (p < 0.001) and presence of mucosal invasion (p = 0.01). Expression of CD117 was seen in 94%, CD34 in 59%, SMA in 41%, S-100 in 33%, and desmin in 4% of tumors.

CONCLUSION

We found GIST to be the most common mesenchymal tumor of the gastrointestinal tract.

[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.

Prognostic time dependence of deletions affecting codons 557 and/or 558 of KIT gene for relapse-free survival (RFS) in localized GIST: a Spanish Group for Sarcoma Research (GEIS) Study

BACKGROUND

To assess whether deletions involving codons 557 and/or 558 (critical deletions) of exon 11 of KIT are relevant in the prognosis of relapse-free survival (RFS) in gastrointestinal stromal tumor (GIST) patients with a long follow-up.

PATIENTS AND METHODS

A univariate and multivariate analysis for RFS were carried out on 162 localized GIST patients over the entire follow-up period and over the intervals 0-4 years and >4 years. Factors assessed among others were Fletcher/National Institutes of Health and Miettinen-Lasota/Armed Forces Institute of Pathology (M-L/AFIP) risk categories, critical deletions and non-deletion-type mutation (NDTM) within exon 11 of KIT.

RESULTS

Multivariate analyses revealed that M-L/AFIP [relative risk (RR) 11.45, confidence interval (CI) 4.40-29.76, for the high-risk subgroup and RR 5.97, CI 2.09-17.06, for the intermediate subgroup] and critical deletions (RR 3.05, CI 1.59-5.85) were independent prognostic factors for RFS for the first 4 years and for the entire follow-up period. Beyond 4 years, the high-risk M-L/AFIP subgroup (RR 8.12, CI 1.48-44.4) and NDTM (RR 6.42, CI 1.17-35.12) were independent prognostic factors for RFS. The median follow-up was 84 months.

CONCLUSION

Critical deletions represent a time-dependent prognostic factor limited to the first 4 years after surgery, which could help identify a subset with higher and earlier risk for relapse in GIST patients.

Surgical management of gastrointestinal stromal tumors: analysis of outcome with respect to surgical margins and technique

This report reviews the methods and goals of treatment of gastrointestinal stromal tumor (GIST), the most common mesenchymal tumor of the gastrointestinal tract. GISTs express CD117, which serves as an immunohistochemical diagnostic marker. Surgical excision is the definitive treatment for all primary GISTs greater than 2 cm without evidence of peritoneal seeding or metastasis. Preoperative or intraoperative biopsy is not indicated except when the differential diagnosis includes another type of malignancy. Resection may be performed by traditional open surgery or by laparoscopic or laparoscopy-assisted procedures. Regardless of the approach, oncological precautions must be strictly observed. Tumor disruption is to be avoided at all costs; tumor enucleation leaves a tumor-seeded pseudocapsule behind and is considered insufficient. Because GISTs rarely metastasize through the lymphatics, routine lymphadenectomy is not indicated. The importance of achieving negative microscopic margins is controversial, although patients who undergo incomplete microscopic resection may be at greater risk of locoregional recurrence. Other factors, such as tumor grade and size, may play a more significant role in predicting recurrence. Cases of advanced disease or involvement of adjacent structures should be evaluated on an individual basis by a multidisciplinary team.

A systematic review on the clinical diagnosis of gastrointestinal stromal tumors

BACKGROUND

The aim of this work was to assess the prevalence of symptoms of gastrointestinal stromal tumors (GISTs) and the diagnostic yield of clinical procedures for its diagnosis.

METHODS

Medical databases were consulted between 1998 and 2006 for potentially relevant publications. All studies dealing with the clinical presentation of GIST and related diagnostic procedures were included. Two researchers worked independently on the study selection, quality assessment, data extraction, and analysis phases of the study.

RESULTS

Forty-six observational studies were included with a total of 4,534 patients. Gastrointestinal bleeding was the most common clinical presentation. Twenty studies provided adequate information on the diagnostic yield of various procedures. The pooled diagnostic yield of endoscopy + mucosal biopsy and of intestinal contrast radiography was 33.8% (0-100%) and 35.1% (11-100%), respectively, while that of EUS and that of EUS-FNA was 68.7% (40-100%) and 84.0% (73.8-100%), respectively. Abdominal CT scan and MRI had similar pooled diagnostic yields: 73.6% (34.8-100%), and 91.7% (75-100%), respectively.

CONCLUSION

Endoscopy + mucosal biopsy should be reserved to patients with gastrointestinal bleeding. EUS-FNA provides direct visualization of the neoplasm and adequate samples for molecular diagnosis. EUS, abdominal CT and MRI may be considered valid alternatives whenever EUS-FNA is unavailable or a cytological diagnosis is unnecessary.

Which is the optimal risk stratification system for surgically treated localized primary GIST? Comparison of three contemporary prognostic criteria in 171 tumors and a proposal for a modified Armed Forces Institute of Pathology risk criteria

BACKGROUND

This study aims to validate and compare the performance of the National Institute of Health (NIH) criteria, Huang modified NIH criteria, and Armed Forces Institute of Pathology (AFIP) risk criteria for gastrointestinal stromal tumors (GISTs) in a large series of localized primary GISTs surgically treated at a single institution to determine the ideal risk stratification system for GIST.

METHODS

The clinicopathological features of 171 consecutive patients who underwent surgical resection for GISTs were retrospectively reviewed. Statistical analyses were performed to compare the prognostic value of the three risk criteria by analyzing the discriminatory ability linear trend, homogeneity, monotonicity of gradients, and Akaike information criteria.

RESULTS

The median actuarial recurrence-free survival (RFS) for all 171 patients was 70%. On multivariate analyses, size >10 cm, mitotic count >5/50 high-power field, tumor necrosis, and serosal involvement were independent prognostic factors of RFS. All three risk criteria demonstrated a statistically significant difference in the recurrence rate, median actuarial RFS, actuarial 5-year RFS, and tumor-specific death across the different stages. Comparison of the various risk-stratification systems demonstrated that our proposed modified AFIP criteria had the best independent predictive value of RFS when compared with the other systems.

CONCLUSION

The NIH, modified NIH, and AFIP criteria are useful in the prognostication of GIST, and the AFIP risk criteria provided the best prognostication among the three systems for primary localized GIST. However, remarkable prognostic heterogeneity exists in the AFIP high-risk category, and with our proposed modification, this system provides the most accurate prognostic information.