An enhanced risk-group stratification system for more practical prognostication of clinically malignant gastrointestinal stromal tumors. Int J Clin Oncol. 2007;12:369-374. [PMID: 17929119 DOI: 10.1007/s10147-007-0705-7]

Colonoscopy Leads to A Diagnosis of A Jejunal Gastrointestinal Stromal Tumour (GIST)

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the gastrointestinal (GI) tract, but are the least common of small intestinal malignant neoplasms. While GI bleeding is the most common clinical presentation of GISTs, intussusception and obstruction are uncommon, as GISTs rarely grow into the lumen. We describe an unusual case of a 50-year-old male who presented with intermittent obscure, overt GI bleeding requiring multiple hospital admissions and blood transfusions. His work-up included abdominal CT imaging, small bowel follow-through, gastroscopies, push enteroscopy, colonoscopies, and anterograde and retrograde double-balloon enteroscopies. Complicating his presentation were colonic angiodysplasias and the development of recurrent venous thromboembolism requiring anticoagulation. Within an hour after an apparently uncomplicated colonoscopy, he developed an acute abdomen secondary to a jejunal intussusception, which led to a laparoscopic small bowel resection and the diagnosis of a jejunal GIST. Given his GIST had no high-risk features, ongoing surveillance with abdominal CT imaging was arranged. This case illustrates the complex presentation and diagnostic difficulty of a jejunal GIST causing obscure, overt GI bleeding and this is the first reported case of a jejunal intussusception following colonoscopy. Due to its submucosal location, multiple endoscopic approaches had failed to diagnose the GIST prior to surgery.

Validation of the Joensuu risk criteria for primary resectable gastrointestinal stromal tumour - the impact of tumour rupture on patient outcomes

BACKGROUND

Approval of imatinib for adjuvant treatment of gastrointestinal stromal tumours (GIST) raised discussion about accuracy of prognostic factors in GIST and the clinical significance of the available risk stratification criteria.

METHODS

We studied the influence of a new modification of the NIH Consensus Criteria (the Joensuu risk criteria), NCCN-AFIP criteria, and several clinicopathological factors, including tumour rupture, on relapse-free survival (RFS) in a prospectively collected tumour registry series consisting of 640 consecutive patients with primary, resectable, CD117-immunopositive GIST. The median follow-up time after tumour resection was 39 months. None of the patients received adjuvant imatinib.

RESULTS

The median RFS time after surgery was 50 months. In univariable analyses, high Joensuu risk group, tumour mitotic count >5/50 HPF, size >5 cm, non-gastric location, tumour rupture (7% of cases; P = 0.0014) and male gender had adverse influence on RFS. In a multivariable analysis mitotic count >5/50HPF, tumour size >5 cm and non-gastric location were independent adverse prognostic factors. Forty, 151, 86 and 348 patients were assigned according to the Joensuu criteria to very low, low, intermediate and high risk groups and had 5-year RFS of 94%, 94%, 86% and 29%, respectively.

CONCLUSION

The Joensuu criteria, which include 4 prognostic factors (tumour size, site, mitotic count and rupture) and 3 categories for the mitotic count, were found to be a reliable tool for assessing prognosis of operable GIST. The Joensuu criteria identified particularly well high risk patients, who are likely the proper candidates for adjuvant therapy.

Advances in clinicopathological classification and genotyping of gastrointestinal stromal tumors

In recent years, the discovery of new markers and advances in mutation detection technologies have made it easy to diagnose gastrointestinal stromal tumor (GIST). However, it is still difficult to predict the biological behavior of GIST. Currently, the most prevalent GIST classification systems, including the National Institutes of Health (NIH) consensus criteria for assigning risk to gastrointestinal stromal tumors (2008 Revision) and the International Union Against Cancer TNM classification of malignant tumors (2010 version), are based on tumor size, mitotic rate, tumor location, and presence of a tumor rupture or not. Molecular genetic studies have shown that genotype of GIST is closely related to tumor prognosis and response to imatinib mesylate.

Different sites and prognoses of gastrointestinal stromal tumors of the stomach: report of 187 cases

BACKGROUND

The stomach is the most common site of gastrointestinal stromal tumors (GISTs), but the clinical behavior of gastric GISTs at different sites is unclear. This study was designed to evaluate the clinicopathological (CP) parameters and influence of different gastric sites on outcome in patients with GIST.

METHODS

The CP and follow-up records of 187 patients with GIST who were treated at TianJin Medical University Cancer Institute & Hospital between January 1985 and December 2006 were reviewed. There were 97 men and 90 women (aged 17-88 (median, 56.5) years). CP factors were assessed for overall survival (OS) by using univariate and multivariate analysis.

RESULTS

The numbers of cases of upper, middle, and lower third gastric GISTs were 69 (36.9%), 103 (55.1%), and 15 (8%), respectively. Sites of GISTs in the middle or upper stomach, tumor size, intermediate- or high-risk groups, high mitotic count, and low resection status were associated with poor OS (p = 0.041, 0.046, 0.006, 0.000, 0.000, respectively) in a univariate analysis. In a multivariate analysis, tumor location in the upper and middle third of the stomach (p = 0.035), an intermediate or high risk (p = 0.01), and incomplete resection status (p = 0.006) were predictive of poor OS.

CONCLUSIONS

Patients in intermediate- and high-risk groups had an unfavorable outcome. A complete resection is the most important treatment for survival. The location of GIST in the lower third of the stomach may be a favorable factor, and the significance of different tumor sites for prognosis of gastric GISTs needs to be further clarified.

Added value of molecular targeted agents in oncology

The treatment of certain cancers has been revolutionised in recent years by the introduction of novel drugs designed to target specific molecular factors implicated in tumour growth. Notable examples include trastuzumab, a humanized monoclonal antibody (mAb) against human epidermal growth factor receptor (HER)-2 in women with HER2-positive breast cancer; rituximab, an anti-CD20 mAb in patients with non-Hodgkin's lymphoma; imatinib, a tyrosine kinase inhibitor in KIT-positive gastrointestinal stromal tumours and sunitinib, another tyrosine kinase inhibitor, in metastatic renal cell carcinoma. For regulatory reasons, new molecular targeted agents are first evaluated in advanced and metastatic disease, wherein they prolong survival. However, their most profound impact has been observed in the adjuvant setting, where they may contribute to curative therapy rather than mere palliation. Expansion in the use of molecular targeted therapies will have important cost implications for health care systems. Although expensive, on a monthly basis, molecular targeted therapies may not be more costly than treatments for other major chronic diseases, especially considering the contribution of cancer to the global disease burden, the associated socioeconomic costs and the long-term benefits of therapy. Nevertheless, the use of these agents must be optimised, in part using molecular biomarkers associated with drug response.

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.

Adjuvant and neoadjuvant therapy for primary GIST

Adjuvant therapy for primary GIST has proven benefit in extending disease free survival. Defined risk factors for recurrent disease are based on GIST size, location, and mitotic rate and provide useful guidelines for selecting patients for adjuvant therapy considerations. Neoadjuvant therapy with tyrosine kinase inhibition has potential usefulness in primary GIST, although not yet as standard of care. Advantages can include tumor downsizing to provide opportunity for less morbid surgical resection as well as to decrease risk of intra-op tumor rupture. These theoretical considerations have not been evaluated in large clinical studies.

Traumatic rupture of a gastrointestinal stromal tumour with intraperitoneal bleeding and haematoma formation

A 40-year-old man presented with acute abdominal pain and falling haemoglobin after a history of minor abdominal trauma. Radiological imaging showed a large soft tissue mass situated between the anterior stomach wall and peritoneum. At diagnostic laparoscopy, intra-abdominal blood and an encapsulated haematoma were found. The procedure was converted to midline laparotomy and the mass was excised, including a stalk of tissue that connected the mass to the anterior prepyloric stomach wall. The patient recovered well and was discharged after 9 days. Histology confirmed a gastrointestinal stromal tumour surrounded by haematoma formation.

Diagnosis and treatment of gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract with malignant potential. Because of the lack of specific clinical manifestations, an accurate preoperative diagnosis of GIST is very difficult. In recent years, the pathogenesis of GIST has been gradually clarified, and their diagnosis and treatment have been greatly improved. Oncogenic mutation of the KIT receptor tyrosine kinase is found in the majority of patients with GIST. Immunohistochemical detection of markers such as CD117 is key to the diagnosis of GIST. Although combined therapy has been emphasized recently, radical surgical treatment is still the most effective option for GIST. Postoperative molecular targeted therapies, including neoadjuvant therapy and adjuvant therapy, can greatly improve the outcomes of patients with GIST. The development of imatinib offers new hope to patients with GIST.

Loss of RKIP expression is associated with poor survival in GISTs

Gastrointestinal stromal tumours (GISTs) are rare mesenchymal tumours of the digestive tract and are commonly driven by oncogenic mutations in KIT and PDGFRA genes. Tumour size, location, mitotic index and KIT/PDGFRA mutations are the most important prognostic parameters in GISTs. However, additional studies screening for new molecular prognostic markers in GISTs are missing. Raf kinase inhibitor protein (RKIP) has been considered as a suppressor of metastasis and a prognostic marker in several neoplasms. In the present study we aimed to examine whether RKIP expression is associated with GIST clinical-pathological features. Using immunohistochemistry, we determined RKIP expression levels in a well-characterised series of 70 GISTs. We found that RKIP is expressed in the great majority of cases, and absent in approximately 9% of GISTs. Additionally, we found that loss of RKIP expression was not due to the promoter methylation as assessed by methylation-specific PCR. Loss of RKIP expression was associated with poor disease-specific survival and with tumour necrosis in GISTs. Furthermore, a statistical tendency was observed between the positive RKIP expression and absence of metastasis. So far, this is the first study assessing RKIP expression levels in GISTs. We conclude that loss of RKIP expression could have an important role as prognostic marker in GISTs.

Partial gastrectomy using natural orifice translumenal endoscopic surgery (NOTES) for gastric submucosal tumors: early experience in humans

BACKGROUND

Transvaginal endoscopic gastric surgery is one of the cutting edge procedures in the field of natural orifice translumenal endoscopic surgery (NOTES). Its feasibility has been shown sporadically in bariatric cases but not in oncologic conditions. The authors report their early experience with hybrid transvaginal NOTES gastrectomy for gastric submucosal tumors (SMTs).

METHODS

Two female patients with SMTs in the distal stomach participated in this institutional review board (IRB)-approved study. Surgical indication was determined according to the National Comprehensive Cancer Network (NCCN) sarcoma guidelines, and the study adhered to the following oncologic principles: no direct handling of the lesion, full-thickness resection, and reasonable surgical margins. The study protocol required a minimum of two laparoscopic ports to ensure procedural safety and aforementioned oncologic appropriateness. Under laparoscopic guidance, a transvaginal route was created and secured with a 50-cm flexible overtube. A gastrointestinal endoscope was introduced, and the perigastric dissection was performed using an insulation-tipped diathermy knife (IT knife) and needle knife. This process was assisted with two laparoscopic graspers. After perigastric mobilization, the transvaginal endoscope was replaced with a digital stapling device, and partial gastrectomy was accomplished. The resected specimen was isolated and delivered through the vagina, and the vaginal wound was closed under direct vision. Outcomes measurements included surgical results, pain scoring, and clinical outcomes.

RESULTS

Both operations were completed successfully in compliance with the aforementioned oncologic principles. The operating time was 365 and 170 min, respectively. The estimated blood loss was negligible. A minilaparotomy for specimen delivery was successfully avoided in both cases. A minimal vaginal incision was added for one patient at retrieval. Postoperatively, both patients reported no pain and recovered rapidly. The final diagnosis was hemorrhagic lipoma and gastrointestinal stromal tumor (GIST), respectively.

CONCLUSION

Our initial experience with human transvaginal NOTES gastrectomy showed it to be feasible and safe for gastric SMTs. It is a complex but promising surgical alternative for female oncologic patients undergoing partial gastric resection.