Management of peritoneal and hepatic metastases from gastrointestinal stromal tumors

Gross and microscopic changes of liver neoplasms and background hepatic structures following neoadjuvant therapy

Liver transplantation is a surgical option with curative intent used in the management of some cases of hepatocellular carcinoma and cholangiocarcinoma (hilar, rarely intrahepatic). A number of different therapeutic modalities including ablative techniques, arterially directed therapies, radiation and chemotherapy are used in the neoadjuvant setting prior to liver transplantation with the goals of preventing tumour progression, decreasing post-transplant recurrence and possibly downstaging patients with tumour burden beyond what is acceptable by current transplant criteria. Pathologists evaluating hepatic explants must be aware of these neoadjuvant therapies and the alterations induced by them in both tumourous and non-tumourous tissue. In this review, we discuss common neoadjuvant therapies used in in this setting, as well as the gross and microscopic changes induced by these presurgical treatments within hepatic neoplasms as well as the background hepatic parenchyma and nearby structures. Select secondary tumours involving the liver which are pretreated will also be discussed. Finally, proper reporting of these changes will be mentioned.

PK/TD modeling for prediction of the effects of 8C2, an anti-topotecan mAb, on topotecan-induced toxicity in mice

To facilitate the development of an inverse targeting strategy, where anti-topotecan antibodies are administered to prevent systemic toxicity following intraperitoneal topotecan, a pharmacokinetic/toxicodynamic (PK/TD) model was developed and evaluated. The pharmacokinetics of 8C2, a monoclonal anti-topotecan antibody, were assessed following IV and SC administration, and the data were characterized using a two compartmental model with nonlinear absorption and elimination. A hybrid PK model was constructed by combining a PBPK model for topotecan with the two-compartment model for 8C2, and the model was employed to predict the disposition of topotecan, 8C2, and the topotecan-8C2 complex. The model was linked to a toxicodynamic model for topotecan-induced weight-loss, and simulations were conducted to predict the effects of 8C2 on the toxicity of topotecan in mice. Increasing the molar dose ratio of 8C2 to topotecan resulted in a dose-dependent decrease in the unbound (i.e., not bound to 8C2) topotecan exposure in plasma (AUCf) and a decrease in the extent of topotecan-induced weight-loss. Consistent with model predictions, toxicodynamic experiments showed substantial reduction in the percent nadir weight loss observed with 30 mg/kg IP topotecan after co-administration of 8C2 (20 ± 8% vs. 10 ± 8%). The investigation supports the use of anti-topotecan mAb to reduce the systemic toxicity of IP topotecan chemotherapy.

[Minimally invasive management of metastases from gastrointestinal stromal tumors]

Minimally invasive radiological procedures can lead to an improvement in the prognosis and the clinical symptoms in cases of metastases of gastro-intestinal stromal tumors (GIST) in the context of multimodal therapy concepts. In the context of interdisciplinary therapy decision-making radiofrequency ablation (RFA) and transarterial tumor embolization should be considered.

Diagnosis and multi-disciplinary management of hepatic metastases from gastrointestinal stromal tumour (GIST)

AIM

To explore the present application of diagnosis and management of hepatic metastases from GIST.

METHODS

We performed a systematic review of the literature for studies concerning hepatic metastases from GIST. A literature search was performed using the Medline/PubMed databases to identify publications relevant to the review published from January 1998 to December 2008. Totally 113 relevant articles were retrieved. Abstracts from recent ASCO symposia were hand searched for relevant articles. After the primary filtration, articles on review and with repetitive content were excluded. The articles on clinical research, which were issued in authorized journals, were selected. At last, totally 69 articles were included for review.

FINDINGS

The rate of liver metastases was reported as 15.9% in primary GISTs. The recurrence rate following surgical resection for hepatic metastases from GIST had been reported as 70-77%. For metastatic GIST patients with tyrosine kinase inhibitor (TKI) treatment, it demonstrated rates of CR, PR and SD respectively of 5.84%, 50.7%, and 32.4%. Combining repeated surgery with TKI treatment, R0/R1 resection rates range in various series between 48 and 82%. For those patients with unresectable disease confined to the liver or unable to tolerate liver resection due to co-morbidity or advanced age, RFA, HACE, TKI therapy, or even liver transplantation, can also improve survival.

CONCLUSIONS

The liver is a common metastatic site for gastrointestinal stromal tumour (GIST). Appropriate initial evaluation remains paramount for selecting the correct management strategy. Multi-disciplinary management (which includes pathology, medical oncology, surgical oncology, and imaging expertise) of this disease is important for both curative and palliative treatment in these patients. Combining repeated surgery with TKI treatment may be the most effective management for GIST patients with liver metastases.

Isolated hepatic perfusion with 200 mg melphalan for advanced noncolorectal liver metastases

Purpose

The liver is one of the most common sites for metastatic solid tumors. If the liver is the only site of metastatic disease, regional treatment options can offer the benefit of high local exposure with limited systemic toxicity, especially for patients without (further) systemic treatment options. We report the results of our experience with isolated hepatic perfusion (IHP) in patients with isolated liver metastases from a variety of primary tumors.

Patients and Methods

Nineteen patients with isolated unresectable liver metastases from a variety of tumors (13 uveal melanomas, 2 neuroendocrine carcinomas, 2 gastrointestinal stromal tumors, 1 hepatocellular carcinoma, and 1 high-grade sarcoma) were treated with a 60-min IHP using 200 mg melphalan. Patients were monitored for toxicity, response according to response evaluation criteria in solid tumors (RECIST) criteria, and survival.

Results

One melanoma patient was not perfused due to insufficient isolation of the liver. There was no treatment-related mortality. Reversible grade 3 or 4 hepatoxicity occurred in 10 (56%) patients, while veno-occlusive disease occurred in 4 (22%) patients. Of the 12 uveal melanoma patients who were perfused, 4 (33%) patients had a partial hepatic response, 6 (50%) patients had stable hepatic disease, and 2 (17%) patients were immediately progressive. Median disease-free survival was 6.6 months with a median overall survival of 10.0 months. Fifty percent of other primary tumors showed at least partial remission, including one complete remission in a high-grade sarcoma patient.

Conclusion

IHP with melphalan shows activity in patients with liver metastases from a variety of primary tumors, but other or additional drugs may improve therapeutic outcome.

Primary stromal tumor of the omentum: Report of a case

We report the case of a primary extragastrointestinal stromal tumor (EGIST) found in the omentum of a 65-year-old woman. The resected specimen, which measured 6 cm at its largest point, consisted of an outer solid part and inner uniloculated cysts. Microscopically, the tumor was characterized by interlacing bundles of elongated spindle cells, with the nuclei showing a focal palisading pattern; however, skenoid fibers were not observed anywhere and mitoses were absent. Immunohistochemically, the tumor was negative for smooth-muscle actin, desmin, and S-100 protein, but it was positive for CD117 and CD34. The microscopic features were consistent with a gastrointestinal stromal tumor.

Aggressive surgical resection for the management of hepatic metastases from gastrointestinal stromal tumours: a single centre experience

BACKGROUND

The outcome of surgical intervention for hepatic metastases from gastrointestinal stromal tumours (GIST) is still uncertain. This study evaluated the outcome of patients following aggressive surgical resection and Imatinib mesylate therapy (IM).

PATIENTS AND METHODS

This was a retrospective analysis of patients managed with hepatic metastases from GIST over a 13-year period (January 1993 to December 2005).

RESULTS

Twelve patients were identified with a median age at diagnosis of 62 (32-78) years. The primary sites of GIST were stomach (n=5), jejunum (n=4), sigmoid (n=1), peritoneum (n=1) and pancreas (n=1). Eleven patients underwent surgical resection with curative intent and one patient had cytoreductive surgery. Following surgery with curative intent (n=11), the overall 2- and 5-year survival rates were both 91%, whereas the 2- and 5-year disease-free rates following primary hepatic resection were 30% and 10%, respectively. The median disease-free period was 17 (3-72) months. Eight patients had recurrent disease and were managed with further surgery (n=3), radiofrequency ablation (RFA) (n=2) and IM (n=8). Overall, there are four patients who are currently disease-free: two patients following initial hepatic resection and two patients following further treatment for recurrent disease. There was no significant association in clinicopathological characteristics between patients with recurrent disease within 2 years and patients who were disease-free for 2 years or more. Overall morbidity was 50% (n=6), with one postoperative death. The follow-up period was 43 (3-72) months.

CONCLUSION

Surgical resection for hepatic GIST metastases may improve survival in selected patients. Recurrent disease can be managed with surgery, RFA and IM.

Gastrointestinal stromal tumors: experience in 49 patients

INTRODUCTION

Gastrointestinal stromal tumours (GIST) are mesenchymal tumours of the digestive tract originated in the interstitial cells of Cajal. They express the tyrosine kinase c-kit (CD117) activity receptor. Mutations in this receptor cause neoplastic development. Curative treatment continues to be radical resection of the tumour and is resistant to commonly employed chemotherapy regimens. Imatinib mesilate is a drug that inhibits c-kit activity expressed by GIST and its activity in these tumours has been demonstrated.

MATERIAL AND METHODS

Retrospective study of all cases of leiomyoma, leiomyosarcoma, schwannoma, and stromal or mesenchymal tumors from 1989 to July 2004. C-kit and CD34 proteins were detected at immunohistochemical study in addition to the usual markers for mesenchymal tumours.

RESULTS

49 GISTs were diagnosed, 26 males and 23 females (mean age 64.1). Symptoms were digestive tract bleeding (n = 13), abdominal pain (n = 13), intestinal occlusion (n = 4) and others. The lesion was located in small bowel (n = 22), stomach (n = 19), rectum (n = 3), peritoneum (n = 2), esophagus (n = 1), omentum (n = 1), and retroperitoneum (n = 1). Forty-three of the 49 patients underwent surgery; radical resection was performed in 37 (75.5%) and palliative surgery in the other six (16.2%). Two of the patients that did not undergo surgery received chemotherapy. At the time of study, 28 (57.14%) patients remained alive, 23 (46.9%) of whom were disease- free and five (10.2%) were not. Nineteen (38.7%) patients died.

CONCLUSIONS

The results of our series are similar to the others published. Before the year 2001, surgery was the only successful option for the GIST. Surgical resection continues being the best treatment to definitively cure this disease. Imatinib is used to treat not only resectable tumours, but even to allow the possibility to make a subsequent rescue surgery. On the other hand, Imatinib is used in the treatment of the metastatic disease.

Tumores gástricos estromales. Diagnóstico, pronóstico y tratamiento quirúrgico actual. Seguimiento de 18 pacientes tratados

INTRODUCTION

Gastrointestinal stromal tumors (GIST) are the most frequent mesenchymal tumors of the digestive tract and their growth is directed through the signaling of the KIT or PDFGRA genes. The objective of the present study was to describe a series of cases of GIST tumors located in the stomach.

PATIENTS AND METHODS

We performed a retrospective, descriptive study of 18 patients diagnosed with gastric GIST and treated by means of gastric resection between July 1996 and June 2004. There were 12 women and six men, with a mean age of 63 years (range 33-84). In all patients, diagnosis was performed with immunohistochemical markers, such as CD34 and CD117. Investigations included endoscopy, abdominal ultrasonography, abdominal computerized axial tomography and fine-needle aspiration biopsy.

RESULTS

The main symptoms were digestive hemorrhage with severe anemia in 10 patients and abdominal pain in seven. In two patients, the tumors were incidental findings during laparotomy. Four patients underwent emergency surgery and the remainder underwent elective surgery. In all patients, gastric resection of variable extension was performed, according to tumoral location. Multicentric tumors were found in two patients. All patients were CD117- and CD34-positive. There were few postoperative complications. One patient died from acute myocardial infarction (5.6%). The mean follow-up was 47.5 months (range, 12-106). One patent died due to spread of a pancreatic neoplasm and the remaining patients are alive and without tumoral recurrence (94.1%).

CONCLUSIONS

Initial symptoms consist of upper gastrointestinal hemorrhage and abdominal pain. Gastroscopy and imaging techniques lead to a suspected diagnosis, which can be confirmed by immunohistochemical studies, in which the "gold standard" is positivity for CD117; CD34 (+), vimentin (+), actin (-) and protein S-100 (-) are also used. Treatment consists of tumoral resection with negative margins.

Application of Anti-Methotrexate Fab Fragments for the Optimization of Intraperitoneal Methotrexate Therapy in a Murine Model of Peritoneal Cancer

Anti-drug antibodies may be used to impart regio-specific alterations in drug disposition, potentially enhancing the therapeutic selectivity of intracavitary chemotherapy. In the present study, we tested the hypotheses that systemic therapy with anti-methotrexate antibodies would allow increases in the maximum tolerated dose of intraperitoneal methotrexate (MTX) and allow increases in the therapeutic efficacy of intraperitoneal MTX in a murine model of peritoneal cancer. Monoclonal anti-MTX Fab antibody fragments (AMF) were produced, purified, and characterized. AMF pharmacokinetics were determined following i.v. bolus injection (0.4 g/kg) and s.c. bolus injection (0.4, 0.8, 2.2 g/kg). MTX efficacy was investigated in mice bearing peritoneal sarcoma 180 tumors, following administration of MTX via 72 h i.p. infusion at 1.9, 2.8, 3.8 mg/kg, and following combination therapy of 7.5 or 10 mg/kg i.p. MTX (72 h infusion) and 4.2 g/kg s.c. AMF. The mean terminal half-life of AMF was found to be 10.9 +/- 3.3 h and was not dose-dependent, and s.c. bioavailability was 28% +/- 7% at 2.2 g/kg. In mice bearing peritoneal tumors, the maximally tolerated dose of i.p. MTX increased from 1.9 mg/kg (following i.p. MTX alone) to 10 mg/kg (with co-administration of s.c. AMF). Median survival times for saline-treated control animals and animals receiving i.p. MTX (1.9, 2.8, 3.8 mg/kg) were 9, 12, 10, and 7 days, respectively. However, for animals receiving combination therapy with i.p. MTX 7.5 or 10 mg/kg and 4.2 g/kg s.c. AMF, median survival time increased to 17 and 14 days, respectively. As such, the present data suggest that systemic administration of AMF may allow increases in the maximally tolerated dose of i.p. MTX, and allow increases in the therapeutic efficacy of i.p. MTX chemotherapy of peritoneal tumors.

The role of surgery in the management of gastrointestinal stromal tumors (GISTs) in the era of imatinib mesylate effectiveness

Surgical resection is the treatment of choice for the gastrointestinal stromal tumors (GISTs). In the literature, the 5-year patient survival after surgical resection, ranged from 48 to 80%, before the era of imatinib mesylate and the exploration of the prognostication criteria. Imatinib mesylate targets an intracellular signaling molecule of the natural history and malignant development of GISTs, and increased the 5-year survival rate, after the resection of primary low-risk GISTs, to similar values to the normal population. For high-risk GISTs, current knowledge which is still under expansion, show major improvement at the 1-year survival rate of more than 90% versus less than 50% before imatinib era. After surgical resection, for both low and high malignant potential GISTs, a closed control directed to the early identification of confined resectable recurrences, is required. This paper assesses the current knowledge of GIST management, motivated by a case of patient with intermediate risk GIST.

Gastrointestinal Stromal Tumors

Gastrointestinal stromal tumors (GISTs) are identified pathologically by the expression of KIT. The management of GISTs has been altered significantly by the development of imatinib mesylate, a tyrosine kinase inhibitor with activity against KIT and platelet-derived growth factor receptors. This article reviews the management of GISTs in the era of molecular therapies. The role of surgery alone or in combination with imatinib in the adjuvant and metastatic setting is discussed. GISTs resistant to imatinib are becoming a clinical challenge; this article discusses novel therapies under development.

Surgery and imatinib in the management of GIST: emerging approaches to adjuvant and neoadjuvant therapy

Gastrointestinal stromal tumor (GIST) is a neoplasm of the gastrointestinal tract, mesentery, or omentum that expresses the protein-tyrosine kinase KIT (CD117) and is the most common mesenchymal tumor arising at these sites. Surgical resection is the first-line intervention for operable GISTs, particularly localized primary tumors, and it was historically the only effective treatment. However, more than half of all GIST patients present with locally advanced, recurrent, or metastatic disease. The 5-year survival rate ranges from 50% to 65% after complete resection of a localized primary GIST and decreases to approximately 35% for patients with advanced disease who undergo complete surgical resection. A total of 40% to 90% of all GIST surgical patients subsequently have postoperative recurrence or metastasis. Imatinib is a potent, specific inhibitor of KIT that has demonstrated significant activity and tolerability in the treatment of malignant unresectable or metastatic GIST, inducing tumor shrinkage of 50% or more or stabilizing disease in most patients. A key strategy for prolonging the survival of patients with GIST is to improve the outcome of surgery. It is possible that the adjuvant and neoadjuvant use of imatinib (e.g., rendering initially inoperable tumors resectable) in the overall management approach to advanced GIST may contribute to surgeons' success in attaining this objective.

Pharmacokinetic-pharmacodynamic modeling of methotrexate-induced toxicity in mice

The prediction of chemotherapeutic efficacy is complicated by "protocol dependencies" in dose-effect and dose-toxicity relationships. It has been proposed that pharmacokinetic-pharmacodynamic mathematical models may allow characterization of chemotherapeutic protocol dependencies, and may facilitate the prediction of chemotherapeutic efficacy; however, few demonstrations exist in the literature. The present study examines the pharmacokinetics and toxicodynamics of methotrexate (MTX), a commonly used anticancer agent, after intraperitoneal (i.p.) administration to mice. MTX was administered via bolus or infusion (24, 72, and 168 h), at doses of 2.5-1000 mg/kg. MTX plasma and peritoneal pharmacokinetics were characterized through standard noncompartmental and compartmental techniques. Body weight loss was used as a measure of MTX-induced toxicity. We found that MTX pharmacokinetics were independent of dose (over a range of 3-600 mg/kg) and independent of dosing mode (i.e., i.p. bolus vs. i.p. infusion). However, MTX-induced toxicity was shown to be highly dependent on the dosing protocol used. For example, the maximally tolerated dose (i.e., the dose related to a mean body weight loss of 10%) was 200-fold greater after bolus administration relative to that observed for 72-h infusion (760 mg/kg vs. 3.8 mg/kg). This profound protocol dependence in the relationship between MTX-induced toxicity and MTX exposure was characterized through the use of a time-dissociated pharmacokinetic-pharmacodynamic model (median prediction error: 3.9%).