Neoadjuvant and adjuvant imatinib treatment in gastrointestinal stromal tumor: current status and recent developments

Monitoring neoadjuvant treatment-induced surgical benefit in GIST patients using CT-based radiological criteria

Objective

This single-centre retrospective study aims to determine the incidence of therapy-induced surgical benefit in patients with non-metastatic gastrointestinal stromal tumour (GIST) treated with neoadjuvant tyrosine kinase inhibitors (TKI) and evaluate whether this can be predicted by radiological response criteria.

Methods

Thirty-nine non-metastatic GIST patients were treated with neoadjuvant TKI treatment, followed by curative-intended surgery, and monitored using contrast-enhanced computed tomography (CE-CT). Surgical benefit was independently assessed by two surgical oncologists and was defined by de-escalation of surgical strategy or reduced surgical complexity. Radiological response between baseline and the last preoperative scan was determined through RECIST 1.1, Choi and volumetric criteria.

Results

In this patient cohort, median neoadjuvant treatment interval was 8.3 (IQR, 3.9-10.6) months. Surgical benefit was gained in 22/39 patients. When comparing radiological criteria to findings on surgical benefit, accuracy, sensitivity, and specificity for RECIST 1.1 (90 %, 100.0 % and 82 %), Choi (64 %, 24 %, and 96 %) and volumetry (95 %, 100.0 %, and 91 %) were calculated. In 30/39 patients, temporal changes in tumour size over the course of treatment was assessed. Tumour volume reduced significantly in the surgical-benefit group compared to the non-benefit group (72 % vs. 25 %, p < 0.01) within three months. 14/19 surgical-benefit patients had an initial volume reduction above 66 %, after which volume reduced slightly with a median 3.1 % (IQR, 2.1-7.8 %) reduction.

Conclusion

Surgical benefit after neoadjuvant treatment was achieved in 56 % of patients and was most accurately reflected by size-based response criteria. In patients with therapy-induced surgical benefit, nearly all treatment-induced volume reductions were achieved within three months.

Early Prediction and Monitoring of Treatment Response in Gastrointestinal Stromal Tumors by Means of Imaging: A Systematic Review

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms. Tyrosine kinase inhibitor (TKI) therapy is currently part of routine clinical practice for unresectable and metastatic disease. It is important to assess the efficacy of TKI treatment at an early stage to optimize therapy strategies and eliminate futile ineffective treatment, side effects and unnecessary costs. This systematic review provides an overview of the imaging features obtained from contrast-enhanced (CE)-CT and 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) PET/CT to predict and monitor TKI treatment response in GIST patients. PubMed, Web of Science, the Cochrane Library and Embase were systematically screened. Articles were considered eligible if quantitative outcome measures (area under the curve (AUC), correlations, sensitivity, specificity, accuracy) were used to evaluate the efficacy of imaging features for predicting and monitoring treatment response to various TKI treatments. The methodological quality of all articles was assessed using the Quality Assessment of Diagnostic Accuracy Studies, v2 (QUADAS-2) tool and modified versions of the Radiomics Quality Score (RQS). A total of 90 articles were included, of which 66 articles used baseline [18F]FDG-PET and CE-CT imaging features for response prediction. Generally, the presence of heterogeneous enhancement on baseline CE-CT imaging was considered predictive for high-risk GISTs, related to underlying neovascularization and necrosis of the tumor. The remaining articles discussed therapy monitoring. Clinically established imaging features, including changes in tumor size and density, were considered unfavorable monitoring criteria, leading to under- and overestimation of response. Furthermore, changes in glucose metabolism, as reflected by [18F]FDG-PET imaging features, preceded changes in tumor size and were more strongly correlated with tumor response. Although CE-CT and [18F]FDG-PET can aid in the prediction and monitoring in GIST patients, further research on cost-effectiveness is recommended.

Clinicopathological features and prognosis of colonic and rectal gastrointestinal stromal tumors: A propensity score matching analysis

Background

Colonic gastrointestinal stromal tumor (cGIST) and rectal gastrointestinal stromal tumor (rGIST) are two rare subtypes of gastrointestinal stromal tumor (GIST). The view that colonic and rectal carcinoma are different is generally accepted; however, whether there is a difference between cGIST and rGIST is still unknown. Here, we aimed to provide evidence for future clinical management and research by comparing the differences between the two types of GIST in the above-mentioned aspects.

Methods

Patients were enrolled from three medical centers in China and published literature was collected following the inclusion and exclusion criteria. Propensity score matching was used to eliminate differences between cohorts.

Results

Between cGIST and rGIST patients, significant differences were observed in age, tumor size, mitotic index, NIH risk category, growth pattern, and symptoms. Adjuvant therapy is used in a high proportion of cGIST patients, and neoadjuvant therapy is used in a high proportion of rGIST patients. Although local resection is the main surgical method in both cohorts, the proportion is higher in cGIST patients. The overall survival of rGIST patients was better than that of the cGIST patients before propensity score matching (PSM). Interestingly, no significant differences in prognosis were observed after PSM.

Conclusions

Although there were significant differences between cGIST and rGIST patients in baseline characteristics, clinicopathological features, treatment choice, and overall survival rate before PSM, no significant differences in long-term survival were observed between the two groups after PSM. In our study, there may be no differences in the tumor entity between cGIST and rGIST.

Lack of Prognostic Significance of Connexin-43 Labeling in a Series of 46 Gastrointestinal Stromal Tumors

Background

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors with variable malignant potential. Connexin-43 (C×43) is the commonest gap-junction protein and has been frequently investigated in oncology. Our aim was to establish the immunohistochemical expression of C×43 in relation to GIST location, size, Ki67 index, tumor grade and follow-up.

Materials and methods

The study included postoperative samples of 46 patients treated for GIST in the 1999–2010 time frame. Complete clinical workup was available for 38 patients (82.6%); total surgical resection was carried out in 32 (84.2%) patients, while 13 (34.2%) patients underwent chemotherapy. Median follow-up was 40.7 months (range, 1-134).

Results

The calculated incidence of GIST in our setting was 11.5 per million. C×43 was expressed in 43/46 (93.5%) GIST cases, with a significant difference between stomach- and small intestine-derived tumors (p=0.006). Ki67 was 10% on average (range, 1–22) and was not correlated with tumor location (p=0.194). C×43 did not show significance with regard to tumor size (p=0.264) or higher tumor grade (p=0.658), as opposed to Ki67, which significantly correlated with both (p=0.0048 and p<0.001, respectively). C×43 and Ki67 were not significantly correlated (p=0.708). Ki67 correlated with time to recurrence (p=0.022). Ki67 >11% was taken as the indication to start imatinib chemotherapy (sensitivity 61.5%, specificity 92.0%, p=0.022). Ten (66.7%) of 15 patients with long-term (>5 years) follow-up were in remission.

Conclusion

C×43 was frequently expressed in GISTs regardless of tumor site. However, no significant relationships to histopathological parameters suggestive for prognosis were found. Further investigations might clarify the roles of C×43 in GIST oncogenesis.

Giant Gastric Gastrointestinal Stromal Tumor (GIST)

Gastrointestinal stromal tumors (GIST) represent 0.1-3 % of gastrointestinal malignancy. Surgery is the mainstay of treatment, but in high-risk tumors, imatinib can help to achieve better oncological outcomes. We present a rare case of a patient with gastric GIST with very aggressive evolution in a short period of time despite the use of neoadjuvant therapy with imatinib.

Prediction of Tumor Recurrence in Patients with Non-Gastric Gastrointestinal Stromal Tumors Following Resection according to the Modified National Institutes of Health Criteria

Background/Aims

Few studies have investigated the prognosis of non-gastric gastrointestinal stromal tumors (GISTs) under the modified National Institutes of Health (NIH) consensus criteria in Korea. This study aims to clarify the clinical usefulness of the modified NIH criteria for risk stratification.

Methods

From January 2000 through October 2012, 88 patients who underwent curative resection for primary GISTs were included in this study. The enrolled patients were stratified to predict recurrence by the original NIH criteria and modified NIH criteria.

Results

In all, 88 patients had non-gastric GISTs, including 82 and 6 patients with GISTs of the small intestine and colorectum, respectively. The mean age was 57.3±13.0 years, and the median follow-up duration was 3.40 years (range, 0.02-12.76 years). All patients who were placed in the intermediate-risk category according to the original NIH criteria were reclassified into the high-risk category according to the modified NIH criteria. Therefore, the proportion of cases in the intermediate-risk category declined to 0.0% from 25.0% (22/88), and the proportion of cases in the high-risk category increased to 43.2% (38/88) from 18.2% (16/88) under the modified NIH criteria. Among the 22 reclassified patients, 6 (27.3%) suffered a recurrence during the observational period, and the recurrence rate of high-risk category patients was 36.8% (14/38).

Conclusions

Patients in the high-risk category according to the modified NIH criteria had a high GIST recurrence rate. Therefore, the modified NIH criteria are clinically useful in selecting patients who need imatinib adjuvant chemotherapy after curative surgical resection.

Management of gastrointestinal stromal tumors: looking beyond the knife. An update on the role of adjuvant and neoadjuvant imatinib therapy

BACKGROUND

Gastrointestinal stromal tumors (GISTs) have traditionally been treated with surgical resection alone resulting in high rates of recurrence. However, the discovery of imatinib efficacy in GIST has revolutionized its management.

DISCUSSION

Imatinib may be used as neoadjuvant therapy with the goal of reducing tumor size, minimizing surgical morbidity and, in some cases, rendering inoperable cases operable. In addition, imatinib use in the adjuvant setting to eradicate micrometastases and prevent recurrence has shown promising results in reducing relapse rates. Appropriate patient selection and optimal dose and duration of imatinib therapy remain undecided and require further investigation. We present a literature review and a case report of our patient with a symptomatic gastric GIST managed successfully utilizing neoadjuvant imatinib therapy, laparoscopic limited resection, and adjuvant imatinib therapy.

The impact of incidental gastrointestinal stromal tumours on patients undergoing resection of upper gastrointestinal neoplasms

BACKGROUND

Emerging data suggest asymptomatic gastrointestinal stromal tumours (GISTs) of the upper gastrointestinal (UGI) tract are not uncommon. We sought to determine their incidence in patients undergoing resection for UGI neoplasms and their impact on surgical and adjuvant treatment.

METHODS

We accessed a database prospectively listing all patients undergoing resection of non-GIST neoplasms of the stomach and esophagus at a single university centre over a 4.5-year period and reviewed pathology reports for the presence of synchronous GISTs in the UGI tract. We compared patient demographic and tumour characteristics, operative procedures and postoperative outcomes.

RESULTS

In all, 207 patients undergoing gastrectomy or esophagectomy for non- GIST neoplasms were included. We identified 15 synchronous GISTs in the UGI tract of 11 (5.3%) patients (1 preoperatively, 4 intraoperatively and 10 on final pathology), with an average age of 67 years. Most patients were men. Additional resections were required for GISTs identified pre- or intraoperatively. Final pathology revealed completely resected c-kit positive tumours of an average size of 0.5 (range 0.1-4.0) cm with low or very low risk of malignant potential. No patients received adjuvant therapy for the GISTs. After a median follow-up of 11 (range 2-36) months, 5 patients died from their primary cancer, 3 were alive with primary cancer recurrence, and 3 were alive without disease. No patients experienced GIST recurrence.

CONCLUSION

Incidentally finding a synchronous GIST during resection of UGI neoplasms is not uncommon; it may alter surgical treatment but is unlikely to impact longterm survival.

A neoadjuvant biochemotherapy approach to stage III melanoma: analysis of surgical outcomes

AIMS

Completion lymph node dissection (CLND) and adjuvant therapy are recommended for node-positive melanoma patients. We sought to analyze our institution's experience with neoadjuvant biochemotherapy in stage III patients.

METHODS

Clinical information was extracted from a retrospective database on stage III melanoma patients. Eligible patients received two cycles of biochemotherapy prior to their CLND.

RESULTS

There were 153 patients available for analysis. The average tumor depth was 2.5 mm. More than half of all patients presented with sentinel lymph node-positive disease. Surgical complications occurred in 23% of patients. Patients who experienced an adverse event during their neoadjuvant therapy had a worse overall survival when compared with those who did not (p = 0.005).

CONCLUSION

Our data suggest that aggressive neoadjuvant treatment prior to CLND does not impact surgical complications. Our surgical outcomes are similar to the current literature when adjuvant therapy is used in stage III melanoma. The inability to tolerate neoadjuvant therapy in stage III melanoma is a negative prognostic indicator.

Evolving molecular targets in the treatment of nonmalignant gastrointestinal diseases

Novel treatments for gastrointestinal (GI) diseases are based on molecular targets. Novel pharmacologic and biological agents with greater selectivity and specificity are being developed for a variety of epithelial diseases, including eosinophilic esophagitis (EoE), gastroesophageal reflux disease (GERD), celiac disease, short bowel syndrome (SBS), and inflammatory bowel diseases (IBDs; Crohn's disease and ulcerative colitis). Motility and secretory agents are being developed for gastroparesis, irritable bowel syndrome (IBS), functional constipation, and diarrhea. Here we focus on data from clinical trials involving validated pharmacodynamic or patient response outcomes.

Intervention in gastrointestinal stromal tumour with a high risk of malignancy and associated with thalassaemia minor

This study reports on a 65-year-old female patient with controlled comorbidity, who was diagnosed with gastrointestinal stromal tumours following regular monitoring of renal cysts. After the surgical treatment, coadjuvant treatment with imatinib was initiated. After a few months, the patient complained of angor and asthenia and the diagnosis of anaemic syndrome was made on the basis of blood test results. We studied the causes of the anaemia (maturation factors and other causes of secondary anaemia) and it led to the diagnosis of vitamin B12 deficiency. Treatment with vitamin B12 supplementation was initiated. With the correction of the vitamin levels with supplementation, the symptoms improved. Thalassaemia led to the misdiagnosis of vitamin B12 deficiency because of the lower mean corpuscular volume levels.

Effectiveness of adjuvant imatinib in patients with gastrointestinal stromal tumor: results of a population-based, matched-cohort study

OBJECTIVE

Data are limited on the use of adjuvant imatinib in patients with gastrointestinal stromal tumor (GIST) outside of clinical trials. This retrospective, population-based, matched-cohort study evaluated adjuvant imatinib treatment patterns, assessed impact on clinical outcomes, and estimated effectiveness based on number needed to treat (NNT).

RESEARCH DESIGN AND METHODS

GIST-related claims from the PharMetrics claims database were included (2000-2010). A stepwise identification algorithm identified appropriate patients based on GIST-related ICD-9-CM codes, who were classified as 'imatinib (IM) patients' receiving imatinib within 84 days post-surgery and 'non-imatinib (non-IM) patients' undergoing surgery but not receiving imatinib during the study period. The primary composite outcome was based on incidence of a second GIST-related surgery and long-term follow-up in the matched cohorts. IM patients were matched with up to eight non-IM patients on age, gender, ICD-9-CM code, and first surgery date.

RESULTS

A total of 118 IM and 4088 non-IM patients with possible GIST ICD-9s and surgery were included. The median duration between first and second surgeries was significantly longer in IM than non-IM patients (488 vs. 290 days; p = 0.0005). IM patients also had longer median follow-up from initial surgery to composite outcome (433 vs. 320 days; p = 0.002). Adherence to IM, measured by medication possession ratio, was 0.83 and 0.73 during the first and second years of treatment, respectively. IM patients were less likely to have the composite outcome compared with non-IM patients (hazard ratio = 0.501; p = 0.0005). The NNT to prevent one outcome was 4.

CONCLUSIONS

Patients receiving adjuvant imatinib treatment were less likely to have second surgery or be lost to follow-up, and had a longer interval to second surgery. Although treatment with adjuvant imatinib in patients with primary GIST is effective, adherence to imatinib and treatment duration are less than recommended by current treatment guidelines.

Single-cell proteomic chip for profiling intracellular signaling pathways in single tumor cells

We describe a microchip designed to quantify the levels of a dozen cytoplasmic and membrane proteins from single cells. We use the platform to assess protein-protein interactions associated with the EGF-receptor-mediated PI3K signaling pathway. Single-cell sensitivity is achieved by isolating a defined number of cells (n = 0-5) in 2 nL volume chambers, each of which is patterned with two copies of a miniature antibody array. The cells are lysed on-chip, and the levels of released proteins are assayed using the antibody arrays. We investigate three isogenic cell lines representing the cancer glioblastoma multiforme, at the basal level, under EGF stimulation, and under erlotinib inhibition plus EGF stimulation. The measured protein abundances are consistent with previous work, and single-cell analysis uniquely reveals single-cell heterogeneity, and different types and strengths of protein-protein interactions. This platform helps provide a comprehensive picture of altered signal transduction networks in tumor cells and provides insight into the effect of targeted therapies on protein signaling networks.

Use and costs of oral anticancer agents in the Netherlands in the period 2000-2008

PURPOSE

In recent years, the number of oral anticancer agents has increased substantially. Although these agents have quickly been incorporated in the treatment of a variety of malignancies, data on their incidence, prevalence and costs are lacking. The objective of the present study was to obtain insight into the use and the costs of oral anticancer agents (with Anatomical Therapeutic Chemical classification system (World Health Organisation) code L01) in the Netherlands between 2000 and 2008.

METHODS

Incidence and prevalence were determined using community pharmacy dispensing records obtained from the PHARMO Record Linkage System database. The data of costs were provided by the Genees- en hulpmiddelen Informatie Project of the Dutch Health Care Insurance Board (CVZ, Diemen, The Netherlands).

RESULTS

In the years 2000-2008, the use of oral anticancer agents has more than doubled from 64 to 140 users per 100 000 inhabitants. The increase is mainly caused by the prescription of capecitabine for various indications. There was a 50-fold rise in costs on oral anticancer agents from €2 m in 2000 to approximately €100 m in 2008. The share in the costs of tyrosine kinase inhibitors (TKIs) in 2008 was 67% (€70 m) with the oldest TKI, imatinib, having a share of more than 50% within the group of TKIs.

CONCLUSIONS

The increased use of oral anticancer agents is mainly due to the frequent prescription of capecitabine. The increased costs are caused by the registration of a variety of TKIs, in particular imatinib. The costs of new agents with an orphan drug status are very high as compared with those of capecitabine, a newer agent for which there are alternative treatment options.

Phase 1 clinical trials for sarcomas: the cutting edge

PURPOSE OF REVIEW

Few standard second-line treatment options exist for advanced sarcoma patients. Some of these patients are offered early-phase clinical trials involving targeted or nontargeted agents. This review outlines recent phase 1 trials involving sarcoma patients, explores current challenges and highlights future opportunities in sarcoma developmental therapeutics.

RECENT FINDINGS

New molecularly targeted phase 1 studies have demonstrated efficacy in sarcomas. For instance, insulin-like growth factor-1 receptor (IGF1R) antibodies have produced single agent activity in Ewing's sarcoma. Other promising novel agents include an agonist for the apoptosis ligand 2/tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) for chondrosarcoma, small molecule inhibitor crizotinib for anaplastic lymphoma kinase (ALK)-rearranged inflammatory myofibroblastic tumor, cedarinib for alveolar soft part sarcoma, and rexin-G, a tumor targeted retrovector for osteosarcoma. In addition, different combinations of chemotherapy in combination with newer agents such as trabectedin exhibited efficacy in advanced soft tissue sarcoma.

SUMMARY

Patients with refractory sarcoma demonstrate benefit from treatment with targeted drugs even in the setting of phase 1 trials. Sarcomas that have a defined translocation and those that express specific activated kinases are particularly promising tumors for targeted therapy. The primary challenge is identifying the biomarkers predictive of response or resistance, matching them with specific patient histology, resulting in successful translation of biology into clinical benefit.