Coexpression of receptor-tyrosine-kinases in gastric adenocarcinoma-a rationale for a molecular targeting strategy?

Targeting Patient-Derived Orthotopic Gastric Cancers with a Fluorescent Humanized Anti-CEA Antibody

BACKGROUND

Gastric cancer poses a major diagnostic and therapeutic challenge as surgical resection provides the only opportunity for a cure. Specific labeling of gastric cancer could distinguish resectable and nonresectable disease and facilitate an R0 resection, which could improve survival.

METHODS

Two patient-derived gastric cancer lines, KG8 and KG10, were established from surgical specimens of two patients who underwent gastrectomy for gastric adenocarcinoma. Harvested tumor fragments were implanted into the greater curvature of the stomach to establish patient-derived orthotopic xenograft (PDOX) models. M5A (humanized anti-CEA antibody) or IgG control antibodies were conjugated with the near-infrared dye IRDye800CW. Mice received 50 µg of M5A-IR800 or 50 µg of IgG-IR800 intravenously and were imaged after 72 hr. Fluorescence imaging was performed by using the LI-COR Pearl Imaging System. A tumor-to-background ratio (TBR) was calculated by dividing the mean fluorescence intensity of the tumor versus adjacent stomach tissue.

RESULTS

M5A-IR800 administration resulted in bright labeling of both KG8 and K10 tumors. In the KG8 PDOX models, the TBR for M5A-IR800 was 5.85 (SE ± 1.64) compared with IgG-IR800 at 0.70 (SE ± 0.17). The K10 PDOX models had a TBR of 3.71 (SE ± 0.73) for M5A-IR800 compared with 0.66 (SE ± 0.12) for IgG-IR800.

CONCLUSIONS

Humanized anti-CEA (M5A) antibodies conjugated to fluorescent dyes provide bright and specific labeling of gastric cancer PDOX models. This tumor-specific fluorescent antibody is a promising potential clinical tool to detect the extent of disease for the determination of resectability as well as to visualize tumor margins during gastric cancer resection.

The Role of Angiogenesis Targeted Therapies in Metastatic Advanced Gastric Cancer: A Narrative Review

Since bevacizumab was first approved by the U.S. Food and Drug Administration as an anti-angiogenic therapy in 2004, angiogenesis-targeted therapy has been developed for various types of solid tumors. To date, ramucirumab and apatinib are clinically available as treatments for metastatic advanced gastric cancer (AGC). Ramucirumab demonstrated prolonged survival as second-line therapy of metastatic AGC in the RAINBOW and REGARD trials. However, neither ramucirumab extended survival in treatment-naïve patients with AGC in the RAINFALL or RAINSTORM trials nor bevacizumab in the AVAGAST and AVATAR trials. Apatinib demonstrated superior efficacy over the best supportive care in a Chinese phase III trial but not in an international phase III (ANGEL) trial. Currently, combination therapy of ramucirumab with irinotecan or FTD/TPI is being evaluated in the third-line setting, assessing the efficacy of continuous angiogenesis inhibition from second- to third-line therapy. Recently, the role of angiogenesis inhibition via immunomodulators is attractive to clinicians. Emerging results of several early-phase clinical trials indicated the promising antitumor activity of angiogenesis inhibition in combination with immune therapy. This review offers an overview of the history of clinical trials focused on anti-angiogenic for patients with AGC and presents future perspectives in this area.

Kinase inhibitor screening reveals aurora-a kinase is a potential therapeutic and prognostic biomarker of gastric cancer

Gastric cancer is one of the most common and deadly types of cancer in the world, and poor prognosis with treatment failure is widely reported in the literature. In this context, kinases have been considered a relevant choice for targeted therapy in gastric cancer. Here, we explore the antiproliferative and antimigratory effects of the AURKA inhibitor and the prognostic and therapeutic value as a biomarker of gastric cancer. A total of 145 kinase inhibitors were screened to evaluate the cytotoxic or cytostatic effects in the gastric cancer cell line. Using the Alamar Blue assay, flow cytometry, quantitative polymerase chain reaction, and observation of caspase 3/7 activity and cell migration, we investigated the antiproliferative, proapoptotic, and antimigratory effects of the AURKA inhibitor. Moreover, AURKA overexpression was evaluated in the gastric cell lines and the gastric tumor tissue. Out of the 145 inhibitors, two presented the highest antiproliferative effect. Both molecules can induce apoptosis by the caspases 3/7 pathway in addition to inhibiting cancer cell migration, mainly the AURKA inhibitor. Moreover, molecular docking analysis revealed that GW779439X interacts in the active site of the AURKA enzyme with similar energy as a well-described inhibitor. Our study identified AURKA overexpression in the gastric cancer cell line and gastric tumor tissue, revealing that its overexpression in patients with cancer is correlated with low survival. Therefore, it is feasible to suggest AURKA as a potential marker of gastric cancer, besides providing robust information for diagnosis and estimated survival of patients. AURKA can be considered a new molecular target used in the prognosis and therapy of gastric cancer.

Phase II study of cetuximab plus S-1/cisplatin therapy in Japanese patients with advanced gastric cancer

OBJECTIVE

We evaluated the efficacy and safety of first-line S-1 plus cisplatin in combination with cetuximab for Japanese patients with advanced gastric cancer, including gastroesophageal junction adenocarcinoma.

METHODS

This open-label, single arm, multicenter, phase 2 trial was conducted to assess first-line cetuximab plus S-1 plus cisplatin for advanced gastric cancer. A total of 40 patients from 10 centers were enrolled. Cetuximab was administered weekly, with the initial infusion at 400 mg/m2 and then 250 mg/m2 each subsequent week. S-1 plus cisplatin chemotherapy was concomitantly conducted in a 5-week cycle: S-1 (40-60 mg, adjusted for body surface area) was given twice daily for 3 consecutive weeks, followed by a 2-week rest period, and cisplatin (60 mg/m2) was given on day 8 of each cycle for a maximum of 8 cycles. Treatment continued until the occurrence of radiographically confirmed progressive disease, unacceptable toxicity or withdrawal of consent. The primary endpoint was the best overall response. Secondary endpoints included progression-free survival and safety.

RESULTS

A total of 40 patients were evaluable. One patient (2.5%) had a complete response; 15 patients (37.5%) had a partial response. The observed overall response rate according to the independent review committee was 40.0% (95% confidence interval, 24.9-56.7; P = 0.7043 [one-sided null hypothesis: overall response rate ≤ 43%]); median PFS was 5.6 months (95% confidence intervals, 4.2-8.3). No adverse events leading to death were reported during the study, and no specific safety concerns were observed.

CONCLUSIONS

Overall, the addition of cetuximab to S-1 plus cisplatin was well tolerated in patients with advanced gastric cancer but provided no additional clinical benefit in this study. ClinicalTrials.gov identifier: NCT01388790.

AGAPP: efficacy of first-line cisplatin, 5-fluorouracil with afatinib in inoperable gastric and gastroesophageal junction carcinomas. A Hellenic Cooperative Oncology Group study

PURPOSE

Gastric cancer is the fifth most common neoplasm worldwide with high rates of mortality. Afatinib, a low molecular, irreversible potent inhibitor of ErbB trans-membrane receptor family, has shown promising results according to preclinical and phase I clinical trial data when combined with chemotherapy. We aimed at evaluating the safety and efficacy of the combination of cisplatin, 5FU with afatinib in molecularly unselected patients with advanced gastric cancer.

METHODS

Patients with locally advanced or metastatic gastric/gastroesophageal junction adenocarcinoma received first line combination therapy of cisplatin, 5FU and afatinib every 21 days, followed by afatinib maintenance monotherapy. The primary endpoint was the Objective Response Rate (ORR); secondary endpoints included Overall Survival (OS), Progression Free Survival (PFS) and the safety profile. Unplanned exploratory analysis of HER2 and tumor mutational profile was performed.

RESULTS

Among 55 patients (ITT population) enrolled, 19 (34.5%) achieved an objective tumor response; stable disease was observed in 16 patients (29.1%) and progressive disease in 10 patients (18.2%). The ORR in the per protocol population (PP) was 42.9%. Within a median follow-up of 56 months, the median PFS and OS in the ITT population was 5.0 and 8.7 months, respectively. Seven of the 47 HER2 informative cases carried HER2 positive tumors while TP53, BRCA2 and SMAD4 were the most frequently mutated genes. The most common toxicities were neutrophil count and white blood cell decrease occurring in 56.4% of patients, followed by anemia (50.9%), hyperglycemia (40%), and diarrhea (38.2%).

CONCLUSIONS

The combination of cisplatin/5FU with afatinib did not surpass the benchmarks of efficacy of the contemporary therapeutic regimens that are being applied for the treatment of patients with advanced gastric cancer. However, the observed efficacy and the improved safety profile support that our administration schedule may be further investigated to overcome toxicity problems when integrating afatinib to cytotoxic chemotherapy.

CLINICAL TRIAL REGISTRATION

NCT01743365.

Modifications of Plasma Membrane Organization in Cancer Cells for Targeted Therapy

Modifications of the composition or organization of the cancer cell membrane seem to be a promising targeted therapy. This approach can significantly enhance drug uptake or intensify the response of cancer cells to chemotherapeutics. There are several methods enabling lipid bilayer modifications, e.g., pharmacological, physical, and mechanical. It is crucial to keep in mind the significance of drug resistance phenomenon, ion channel and specific receptor impact, and lipid bilayer organization in planning the cell membrane-targeted treatment. In this review, strategies based on cell membrane modulation or reorganization are presented as an alternative tool for future therapeutic protocols.

Current Targeted Therapies in HER2-Positive Gastric Adenocarcinoma

Gastric cancer is one of the most common types of cancer in the world, usually diagnosed at an advanced stage. Despite the advances in specific anticancer agents' development, the survival rates remain modest, even in early stages. In 15%-20% of cases, the human epidermal growth factor receptor 2 (HER2) overexpression was identified. We conducted a general review to summarize the progress that has been made in the targeted treatment of HER2-positive esogastric junction or gastric adenocarcinoma. According to our findings, trastuzumab is the only validated anti-HER2 agent in locally advanced or metastatic disease and its adjuvant effectiveness is assessed in a RTOG phase III study. In a previously treated advanced disease, the maytansine derivate TDM 1 failed to be approved as a second-line regimen, and the tyrosine kinase inhibitor, lapatinib, shows modest results. The antiangiogenics have not been analyzed in specific populations and targeting the mesenchymal-epithelial transition factor (MET) receptor, overexpressed in up to 46% of the advanced disease, seems encouraging. Regarding the checkpoint inhibitors, based on KEYNOTE 059 multilevel ongoing trial, stratified according to the HER2 and programmed death-ligand (PD-L) 1 status, pembrolizumab was approved for third-line treatment of gastric or gastroesophageal junction adenocarcinoma.

Sunitinib added to FOLFIRI versus FOLFIRI in patients with chemorefractory advanced adenocarcinoma of the stomach or lower esophagus: a randomized, placebo-controlled phase II AIO trial with serum biomarker program

BACKGROUND

As a multi-targeted anti-angiogenic receptor tyrosine kinase (RTK) inhibitor sunitinib (SUN) has been established for renal cancer and gastrointestinal stromal tumors. In advanced refractory esophagogastric cancer patients, monotherapy with SUN was associated with good tolerability but limited tumor response.

METHODS

This double-blind, placebo-controlled, multicenter, phase II clinical trial was conducted to evaluate the efficacy, safety and tolerability of SUN as an adjunct to second and third-line FOLFIRI (NCT01020630). Patients were randomized to receive 6-week cycles including FOLFIRI plus sodium folinate (Na-FOLFIRI) once every two weeks and SUN or placebo (PL) continuously for four weeks followed by a 2-week rest period. The primary study endpoint was progression-free survival (PFS). Preplanned serum analyses of VEGF-A, VEGF-D, VEGFR2 and SDF-1α were performed retrospectively.

RESULTS

Overall, 91 patients were randomized, 45 in each group (one patient withdrew). The main grade ≥3 AEs were neutropenia and leucopenia, observed in 56 %/20 % and 27 %/16 % for FOLFIRI + SUN/FOLFIRI + PL, respectively. Median PFS was similar, 3.5 vs. 3.3 months (hazard ratio (HR) 1.11, 95 % CI 0.70-1.74, P = 0.66) for FOLFIRI + SUN vs. FOLFIRI + PL, respectively. For FOLFIRI + SUN, a trend towards longer median overall survival (OS) compared with placebo was observed (10.4 vs. 8.9 months, HR 0.82, 95 % CI 0.50-1.34, one-sided P = 0.21). In subgroup serum analyses, significant changes in VEGF-A (P = 0.017), VEGFR2 (P = 0.012) and VEGF-D (P < 0.001) serum levels were observed.

CONCLUSIONS

Although sunitinib combined with FOLFIRI did not improve PFS and response in chemotherapy-resistant gastric cancer, a trend towards better OS was observed. Further biomarker-driven studies with other anti-angiogenic RTK inhibitors are warranted.

TRIAL REGISTRATION

This study was registered prospectively in the NCT Clinical Trials Registry (ClinicalTrials.gov) under NCT01020630 on November 23, 2009 after approval by the leading ethics committee of the Medical Association of Rhineland-Palatinate, Mainz, in coordination with the participating ethics committees (see Additional file 2) on September 16, 2009.

Expression profiles of HER2, EGFR, MET and FGFR2 in a large cohort of patients with gastric adenocarcinoma

BACKGROUND

Some tyrosine kinase receptors (RTKs) play critical roles in gastric cancer progression. Not only trastuzumab, but also several other agents targeting RTKs are being investigated for gastric cancer therapy. However, the simultaneous expression of multiple RTKs, which may interfere with the effectiveness of therapeutic agents, has not been evaluated in a large cohort with gastric adenocarcinoma (GAC).

METHODS

We performed a tissue microarray analysis in 950 patients with GAC who underwent a gastrectomy without preoperative chemotherapy. The protein expressions of HER2, EGFR, MET and FGFR2 were evaluated using immunohistochemistry, and the gene amplifications of HER2, EGFR and MET were examined using dual-color in situ hybridization.

RESULTS

The frequency of overexpression was 11.8% for HER2, 23.5% for EGFR, 24.9 % for MET and 31.1% for FGFR2. Whereas strong staining for each of the RTKs was heterogeneous, tumors with homogeneously strong staining areas often exhibited gene amplification. Strong EGFR expression was significantly associated with a poor outcome, but no prognostic correlations were observed in other RTKs. The overexpression of single and multiple RTKs was observed in 40.4 and 22.7% of the cases, respectively. HER2, EGFR, MET and FGFR2 predominance was observed in 10.1, 13.9, 16.1 and 22.9% of the GACs, respectively.

CONCLUSIONS

Approximately two-thirds of patients with GAC exhibited the expression of at least one RTK and would be candidates for targeted therapies. Moreover, one-third of at least one RTK overexspressing cases showed multiple RTKs expression. Our results may be useful for selecting the most suitable patients for each targeted therapy.

VEGFR-3 and CXCR4 as predictive markers for treatment with fluorouracil, leucovorin plus either oxaliplatin or cisplatin in patients with advanced esophagogastric cancer: a comparative study of the Arbeitsgemeinschaft Internistische Onkologie (AIO)

BACKGROUND

Combination of fluoropyrimidines and a platinum derivative are currently standards for systemic chemotherapy in advanced adenocarcinoma of the stomach and gastroesophageal junction (GEJ). Nevertheless, individual likelihood for response to these therapeutic regimes remains uncertain. Even more, no predictive markers are available to determine which patients may benefit more from oxaliplatin versus cisplatin or vice versa. The new invasion and stem cell markers VEGFR-3 and CXCR4 have been linked prognostically with more aggressive esophagogastric cancer types. Thus, we aimed to assess correlations of VEGFR-3 and CXCR4 expression levels with clinical outcome in a randomized phase III study of patients with oxaliplatin/leucovorin/5-FU (FLO) versus cisplatin/leucovorin/5-FU (FLP).

METHODS

The patients data examined in this study (n = 72) were from the collective of the FLO vs. FLP phase III AIO trial. Tumour tissues were stained via immunohistochemistry for VEGFR-3 and CXCR4 expression and results were evaluated by two independent, blinded investigators.Outcome parameter: Survival analysis was calculated for patients receiving FLO vs. FLP in relation to VEGFR-3 and CXCR4 expression.

RESULTS

54% and 36% of the examined tumour tissues showed strong positive expression of VEGFR-3 and CXCR4 respectively. No superiority of each regime was detected in terms of overall survival (OS) in the whole population. Patients with strong expression of CXCR4 on their tumour tissues profited more in terms of OS under the treatment of FLP (mOS: 28 vs 15 months, p = 0.05 respectively). Patients with negative VEGFR-3 and CXCR4 expression had a trend to live longer when FLO regime was applied (mOS: 22 vs. 9 months, p = 0.099 and 20 vs. 10 months, p = 0.073 respectively). In an exploratory analysis of patients older than 60 years at diagnosis, we observed a significant benefit in overall survival for VEGFR-3 and CXCR4-positive patients when treated with FLP (p = 0.002, p = 0.021 respectively).

CONCLUSIONS

CXCR4 positive patients profited in terms of OS from FLP, whereas FLO proved to be more effective in CXCR4 and VEGFR-3 negative patients. Our results suggest, despite the limited size of the study, a predictive value of these biomarkers concerning chemotherapy with FLP or FLO in advanced esophagogastric cancer.

Phase I study of sunitinib plus S-1 and cisplatin in Japanese patients with advanced or metastatic gastric cancer

BACKGROUND

This phase I, dose-finding study evaluated the maximum tolerated dose (MTD), safety, pharmacokinetics, and antitumor activity of sunitinib plus S-1/cisplatin in Japanese patients with advanced/metastatic gastric cancer.

PATIENTS AND METHODS

Patients received oral sunitinib on a continuous daily dosing (CDD) or 2-weeks-on/2-weeks-off schedule (Schedule 2/2; 25 mg/day or 37.5 mg/day), plus S-1 (80-120 mg/day)/cisplatin 60 mg/m(2).

RESULTS

Twenty-seven patients received treatment, including 26 patients treated per protocol (sunitinib 25 mg/day CDD schedule, n = 4; sunitinib 25 mg/day Schedule 2/2, n = 16 [dose-limiting toxicity (DLT) cohort, n = 6 plus expansion cohort, n = 10]; sunitinib 37.5 mg/day Schedule 2/2, n = 6). One patient erroneously self-administered sunitinib 12.5 mg/day and was excluded from the analyses. The MTD was sunitinib 25 mg/day on Schedule 2/2. DLTs were reported for: 2/4 patients given sunitinib 25 mg/day on the CDD schedule; 1/6 patients administered sunitinib 25 mg/day on Schedule 2/2 (grade [G] 3 neutropenic infection, G4 thrombocytopenia, and S-1 dose interruption ≥5 days), and 3/6 patients given sunitinib 37.5 mg/day on Schedule 2/2. Results below are for the overall MTD cohort (n = 16). The most frequently reported G3/4 adverse events were neutropenia (93.8 %) and leukopenia (75.0 %). The objective response rate was 37.5 %; six additional patients experienced no disease progression for ≥24 weeks. Median progression-free survival was 12.5 months. No pharmacokinetic drug-drug interactions were observed between sunitinib/S-1/cisplatin and S-1/cisplatin.

CONCLUSIONS

The MTD of sunitinib was 25 mg/day on Schedule 2/2 combined with cisplatin/S-1 in patients with advanced/metastatic gastric cancer. This regimen had a manageable safety profile and preliminary antitumor activity.

Vascular endothelial growth factor c promotes ovarian carcinoma progression through paracrine and autocrine mechanisms

Vascular endothelial growth factor C (VEGFC) has been reported to promote tumor progression in several tumor types, mainly through the stimulation of lymphangiogenesis and lymphatic metastasis. However, the expression and biological significance of the VEGFC/VEGF receptor (VEGFR)-3 pathway in ovarian cancer growth and dissemination are unclear, and have been investigated in this study. Soluble VEGFC was detected in the plasma and ascites of patients with ovarian carcinoma, and VEGFR3 expression was found in their tumor tissues. In human ovarian carcinoma xenograft models, high levels of soluble VEGFC in ascites and serum were detected, in association with disease progression, tumor burden, and volume of ascites. Peak VEGFC expression preceded para-aortic lymph node infiltration by HOC8 neoplastic cells. Histological detection of tumor cells in blood and lymphatic vessels indicated both hematogenous and lymphatic dissemination. Overexpression of VEGFC in the VEGFR3-positive and luciferase-expressing IGROV1 cells promoted carcinoma dissemination after orthotopic transplantation in the ovary of immunodeficient mice. In vitro, VEGFC released by the tumor cells stimulated tumor cell migration in an autocrine manner. Cediranib, an inhibitor of VEGFR1-3 and c-kit, inhibited in vivo metastasis of VEGFC-overexpressing IGROV1 and in vitro autocrine effects. These findings suggest that the VEGFC/VEGFR3 pathway acts as an enhancer of ovarian cancer progression through autocrine and paracrine mechanisms, hence offering a potential target for therapy.

Phase I study of sunitinib plus capecitabine/cisplatin or capecitabine/oxaliplatin in advanced gastric cancer

BACKGROUND

We evaluated the maximum tolerated dose (MTD) and safety of sunitinib plus capecitabine/cisplatin (XP) or capecitabine/oxaliplatin (XELOX) in Korean patients with advanced gastric cancer (GC).

METHODS

Sunitinib (37.5 or 25 mg/day) was administered on a 2-week-on/1-week-off schedule with chemotherapy. Assessments included dose-limiting toxicity (DLT), safety, pharmacokinetics, and antitumor activity.

RESULTS

Twenty-eight patients received sunitinib/XP; 48 received sunitinib/XELOX. The MTDs were: sunitinib 25 mg/day, cisplatin 80 mg/m(2), and capecitabine 1,000 mg/m(2); sunitinib 37.5 mg/day, oxaliplatin 110 mg/m(2), and capecitabine 800 mg/m(2); and sunitinib 25 mg/day, oxaliplatin 110 mg/m(2), and capecitabine 1,000 mg/m(2). DLTs at the MTDs comprised grade (G) 4 febrile neutropenia plus G3 diarrhea (n = 1; sunitinib/XP), dose delays due to hematologic toxicity (n = 2; both sunitinib/XP), G3 bleeding (menorrhagia; n = 1; sunitinib/XELOX), and G3 increased alanine aminotransferase levels (n = 1; sunitinib/XELOX). There was a high frequency of G3/4 hematologic adverse events observed with both treatment regimens, particularly with sunitinib/XP. Frequent non-hematologic, G3/4 adverse events were nausea, stomatitis, and hypophosphatemia with sunitinib/XP and hypophosphatemia and pulmonary embolism with sunitinib/XELOX. No drug-drug interactions were apparent. At the MTDs, median progression-free survival was 6.4 months and 5.5-8.0 months for sunitinib/XP and sunitinib/XELOX, respectively; and the objective response rate was 46.7% and 43.5-45.5% for sunitinib/XP and sunitinib/XELOX, respectively.

CONCLUSIONS

At the MTD, sunitinib/XELOX had an acceptable safety profile in patients with advanced GC.

Lymphatic endothelial differentiation in pulmonary lymphangioleiomyomatosis cells

Pulmonary lymphangioleiomyomatosis (LAM) is a rare, low-grade neoplasm affecting almost exclusively women of childbearing age. LAM belongs to the family of perivascular epithelioid cell tumors, characterized by spindle and epithelioid cells with smooth muscle and melanocytic differentiation. LAM cells infiltrate the lungs, producing multiple, bilateral lesions rich in lymphatic channels and forming cysts, leading to respiratory insufficiency. Here we used antibodies against four lymphatic endothelial markers-podoplanin (detected by D2-40), prospero homeobox 1 (PROX1), vascular endothelial growth factor receptor 3 (VEGFR-3), and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE1)-to determine whether LAM cells show lymphatic differentiation. Twelve of 12 diagnostic biopsy specimens (early-stage LAM) and 19 of 19 explants (late-stage LAM) showed immunopositivity for D2-40 in most neoplastic cells. PROX1, VEGFR-3, and LYVE1 immunoreactivity varied from scarce in the early stage to abundant in the late stage. Lymphatic endothelial, smooth muscle, and melanocytic markers were partially co-localized. These findings indicate that lymphatic endothelial differentiation is a feature of LAM and provide evidence of a previously unidentified third lineage of differentiation in this neoplasm. This study has implications for the histological diagnosis of LAM, the origin of the neoplastic cells, and potential future treatment with drugs targeting lymphangiogenesis.

Molecular in vivo imaging of gastric cancer in a human-murine xenograft model: targeting epidermal growth factor receptor

BACKGROUND

The prognosis of gastric cancer depends on early diagnosis. Targeted therapies against epidermal growth factor receptors (EGFRs) are currently emerging for the treatment of gastric cancer.

OBJECTIVE

To specifically visualize gastric cancer by using monoclonal antibodies targeting EGFR1 as molecular probes for in vivo molecular confocal laser endomicroscopy (mCLE) in a human-murine xenograft model.

DESIGN

Prospective in vivo animal study.

SETTING

Animal laboratory.

INTERVENTIONS

Human gastric carcinoma xenografts were examined in 26 nude mice by using mCLE after injection of fluorescently labeled antibodies. Nine mice received low-dose anti-EGFR1 antibodies, 7 mice cetuximab, and 7 control mice isotype antibodies. Three mice were screened for autofluorescence without injection. Macroscopic fluorescence was evaluated in 2 additional mice.

MAIN OUTCOME MEASUREMENTS

Molecular imaging of gastric cancer with confocal laser endomicroscopy.

RESULTS

Fluorescence intensity in the anti-EGFR1 (P = .0145) and cetuximab group (P = .0047) was significantly higher than in isotype control mice. The same protocol allowed macroscopic fluorescence detection of tumor xenografts.

LIMITATIONS

Animal model.

CONCLUSIONS

In vivo microscopic and macroscopic molecular imaging of gastric cancer is feasible in a human-murine xenograft model with both diagnostic and therapeutic antibodies targeting EGFR1. In perspective, mCLE could help diagnose and molecularly characterize gastric cancer during ongoing gastroscopy and may even assist in the prediction of response to therapy.

VEGF-D correlates with metastatic disease in gastric cancer patients undergoing surgery

BACKGROUND

The present study was designed to evaluate the impact of the tyrosine kinase ligands VEGF-A/C/D, PDGF-A/B on tumor dissemination and survival in gastric cancer. This is the first study analyzing all these parameters in a homogeneous patient population undergoing surgery.

METHODS

The expression pattern of VEGF-A/C/D and PDGF-A/B was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR) in 69 samples of human gastric adenocarcinoma and correlated with tumor stage and survival.

RESULTS

Expression of the ligand VEGF-D significantly correlated with distant metastatic disease (P=0.00001) but not with patient survival. However, VEGF-A inversely correlated with M1 and grading, PDGF-A inversely correlated with pT and pN category. In contrast, VEGF-C and PDGF-B did not have an impact on clinicopathological parameters.

CONCLUSIONS

The ligand VEGF-D, rather than the other ligands or tyrosine kinase receptors analyzed, is associated with progressive disease in gastric cancer patients undergoing surgery. The VEGF-D ligand might be a helpful marker indicating disseminated disease, and targeting VEGF-D may be a potential therapeutic strategy, although limitations imposed by the selected sample population have to be considered critically.

An open-label, multicentre biomarker-oriented AIO phase II trial of sunitinib for patients with chemo-refractory advanced gastric cancer

BACKGROUND

Sunitinib monotherapy in pretreated patients with advanced gastric cancer (AGC) was investigated. Preplanned analyses of tumour biomarkers on treatment outcome were performed.

PATIENTS AND METHODS

Patients received sunitinib 50mg/day for 4 weeks with 2 weeks rest until disease progression or unacceptable toxicity. The primary end-point was objective response rate (ORR). Secondary end-points included progression-free survival (PFS), overall survival (OS) and safety.

RESULTS

Fifty-two patients were enrolled and treated (safety population, SP). In the intention to treat population (n=51); the ORR was 3.9%, median PFS was 1.28 months [95% CI, 1.18-1.90], median OS was 5.81 months [95% CI, 3.48-12.32], the estimated one-year survival rate was 23.7% [95%CI: 12.8-36.5]. In subgroup analyses, tumour VEGF-C expression compared with no expression was associated with significantly shorter median PFS (1.23 versus 2.86 months, logrank p=0.0119) but there was no difference in tumour control rate (p=0.142). In the SP, serious adverse events occurred in 26 patients, leading to 13 deaths, all sunitinib unrelated. Thirty-eight patients died from progressive disease, nine died <60 days after treatment start.

CONCLUSION

Sunitinib monotherapy was associated with limited tumour response and good/moderate tolerability in this setting.

Clinicopathological significance of platelet-derived growth factor (PDGF)-B and vascular endothelial growth factor-A expression, PDGF receptor-β phosphorylation, and microvessel density in gastric cancer

Background

Angiogenesis is important in the growth and metastasis of various kinds of solid tumors, including gastric cancers. The angiogenic process is triggered by several key growth factors, including vascular endothelial growth factor (VEGF)-A and platelet-derived growth factor (PDGF)-B, that are secreted by tumors. Our aim was to define: i) the expression pattern of VEGF-A and PDGF-B in tumor cells and the activation of PDGF receptor (PDGFR)-β tyrosine kinase in stromal cells of human gastric adenocarcinomas; and ii) the relationship between VEGF-A and PDGF-B expression and microvessel density (MVD), to determine if there is a rationale for a new therapeutic strategy.

Methods

A series of 109 gastric adenocarcinoma cases that had undergone surgical resection was examined immunohistochemically using antibodies against VEGF-A, PDGF-B, and CD34, followed by further examination of PDGFR-β phosphorylation by immunoblotting analysis.

Results

MVD was higher in diffuse-type than intestinal-type cancers (p < 0.001). VEGF-A overexpression correlated to PDGF-B overexpression in both the intestinal-type (p < 0.005) and diffuse-type (p < 0.0001) groups, indicating that VEGF-A and PDGF-B are secreted simultaneously in the same tumor, and may thus play important roles together in angiogenesis. However, several differences between intestinal-type and diffuse-type cancers were observed. In the diffuse-type cancer group, higher MVD was related to the PDGF-B proportion (p < 0.05) and VEGF-A overexpression (p < 0.05), but not to PDGF-B overexpression or the VEGF-A proportion. On the other hand, in the intestinal-type cancer group, higher MVD was correlated to overexpression (p < 0.005), intensity (p < 0.05), and proportion (p < 0.05) of PDGF-B, but not of VEGF-A. In addition, phosphorylation of PDGFR-β was correlated with depth of cancer invasion at statistically significant level.

Conclusions

Our results indicate that PDGF-B, which is involved in the maintenance of microvessels, plays a more important role in angiogenesis in intestinal-type gastric carcinomas than VEGF-A, which plays a key role mainly in the initiation of new blood vessel formation. In contrast, VEGF-A has a critical role for angiogenesis more in diffuse-type cancers, but less in those of intestinal type. Thus, a therapy targeting the PDGF-B signaling pathway could be effective for intestinal-type gastric carcinoma, whereas targeting VEGF-A or both VEGF-A and PDGF-B signaling pathways could be effective for diffuse-type gastric carcinomas.

Cetuximab with irinotecan, folinic acid and 5-fluorouracil as first-line treatment in advanced gastroesophageal cancer: a prospective multi-center biomarker-oriented phase II study

BACKGROUND

Cetuximab plus irinotecan/folinic acid/5-fluorouracil (5-FU) (IF) was evaluated as first-line treatment of patients with advanced gastric cancer and gastroesophageal junction tumors. Preplanned analyses of the influence of tumor biomarkers on treatment outcome were carried out.

PATIENTS AND METHODS

Patients received weekly cetuximab (400 mg/m(2) on day 1, subsequently 250 mg/m(2)) plus irinotecan (80 mg/m(2)) and a 24-hour continuous infusion of folinic acid (200 mg/m(2)) and 5-FU (1500 mg/m(2)) on days 1, 8, 15, 22, 29 and 36 of a 50-day cycle, until progressive disease (PD).

RESULTS

The most common grade 3/4 toxic effects in 49 patients were diarrhea (15%) and skin toxic effects (14%). In 48 assessable patients, the overall response rate was 46% and disease control rate was 79%. Median progression-free survival (PFS) and overall survival (OS) was 9.0 months [95% confidence interval (CI) 7.1-15.6] and 16.5 months (95% CI 11.7-30.1), respectively. Tumor response was more common than nonresponse in epidermal growth factor receptor-expressing tumors (P = 0.041). Tumor PTEN expression was associated with longer PFS (P = 0.035) and OS (P = 0.0127) than no PTEN expression.

CONCLUSION

Cetuximab plus IF was well tolerated and efficacy data were encouraging. This treatment combination and the role of selected biomarkers are under investigation in the ongoing phase III EXPAND trial.

Analysis of anti-proliferative and chemosensitizing effects of sunitinib on human esophagogastric cancer cells: Synergistic interaction with vandetanib via inhibition of multi-receptor tyrosine kinase pathways

The receptor tyrosine kinases (RTKs), epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor 1-3 (VEGFR1-3), are frequently expressed in gastric cancer and are putative therapeutic targets in this disease. We have investigated the anti-proliferative and chemosensitizing properties of the multitargeted small-molecule RTK inhibitors sunitinib and vandetanib in a panel of 4 human gastric and esophageal cancer cell lines. In the 1st instance, the expression of potential targets of these small-molecule inhibitors was examined by reverse transcriptase-polymerase chain reaction, western blotting, and flow cytometry. EGFR mRNA and protein was detected in all cases, with VEGFR2 expression noted in all but 1 line. Both EGF and VEGF were shown to stimulate tumor cell growth, and both sunitinib and vandetanib were found to be associated with significant dose-dependent inhibition of proliferation and an enhancement of apoptosis, as determined by MTT and propidium iodide/Annexin V labeling assays, respectively. The addition of sunitinib to VEGF-stimulated NCI-N87 cells was associated with a reduction in MAPK phosphorylation (pMAPK) but not Akt phosphorylation (pAkt), whereas the addition of vandetanib was associated with reductions in both VEGF- and EGF-mediated VEGFR2 phosphorylation, pMAPK and pAkt. Co-administration of sunitinib significantly enhanced the sensitivity of MKN-45 cells to cisplatin and irinotecan. In addition, vandetanib synergistically enhanced the sunitinib-associated inhibition of gastric cancer cell growth. In conclusion, these preliminary data confirm the importance of EGFR and VEGFR signaling in gastric cancer and suggest that the simultaneous inhibition of RTK-pathways through sunitinib and vandetanib may provide therapeutic benefit in this disease.

Phase II study of sunitinib as second-line treatment for advanced gastric cancer

Purpose. This phase II, open-label, multicenter study assessed the oral, multitargeted, tyrosine kinase inhibitor sunitinib in patients with advanced gastric or gastroesophageal junction adenocarcinoma who had received prior chemotherapy. Experimental design. Patients received sunitinib 50 mg/day on Schedule 4/2 (4 weeks on treatment, followed by 2 weeks off treatment). The primary endpoint was objective response rate; secondary endpoints included clinical benefit rate, duration of response, progression-free survival (PFS), overall survival (OS), pharmacokinetics, pharmacodynamics, safety and tolerability, and quality of life. Results. Of 78 patients enrolled, most had gastric adenocarcinoma (93.6%) and metastatic disease (93.6%). All were evaluable for safety and efficacy. Two patients (2.6%) had partial responses and 25 patients (32.1%) had a best response of stable disease for ≥6 weeks. Median PFS was 2.3 months (95% confidence interval [CI], 1.6–2.6 months) and median OS was 6.8 months (95% CI, 4.4–9.6 months). Grade ≥3 thrombocytopenia and neutropenia were reported in 34.6% and 29.4% of patients, respectively, and the most common non-hematologic adverse events were fatigue, anorexia, nausea, diarrhea, and stomatitis. Pharmacokinetics of sunitinib and its active metabolite were consistent with previous reports. There were no marked associations between baseline soluble protein levels, or changes from baseline, and measures of clinical outcome. Conclusions. The progression-delaying effect and manageable toxicity observed with sunitinib in this study suggest that although single-agent sunitinib has insufficient clinical value as second-line treatment for advanced gastric cancer, its role in combination with chemotherapy merits further study.

K-ras mutation status correlates with the expression of VEGFR1, VEGFR2, and PDGFRalpha in colorectal cancer

AIM

We initiated this study in order to analyze whether the expression level of targeted receptor tyrosine kinases (RTK) is associated with the K-ras mutation status.

METHODS

The expression pattern of VEGFR1, VEGFR2, VEGFR3, PDGFRalpha, PDGFRbeta, and EGFR1 was analyzed in 93 samples of human colorectal carcinoma samples and correlated with the K-ras mutation status as identified by PCR-RFLP.

RESULTS

VEGFR1, VEGFR2, VEGFR3, PDGFRalpha, PDGFRbeta, and EGFR1 were expressed at relevant levels in 95%, 46%, 46%, 85%, 62%, and 82%, respectively. K-ras mutations were present in 53% (codon 12, 47%; codon 13, 6%). Expression of VEGFR1 (P = 0.0263), VEGFR2 (P = 0.0466), and PDGFRalpha (P = 0.0063) was significantly linked to K-ras codon 12 or 13 mutation. In addition, co-expression of VEGFR2 and PDGFRalpha was significantly associated with K-ras mutation (P = 0.0145).

CONCLUSION

Our data reveal that specific RTKs are over-expressed in K-ras mutated cancers. It needs to be addressed in prospective studies whether these patients will benefit from tyrosine kinase inhibitors more than K-ras wild-type.

Development of targeted therapies in advanced gastric cancer: promising exploratory steps in a new era

PURPOSE OF REVIEW

Many chemotherapeutic drugs, including fluoropyrimidines, platinums, CPT-11, taxanes and adriamycin have single-agent activity in advanced gastric cancer. Although combination chemotherapy has been shown to be more effective than single agents, response rates between 30 and 50% have not fulfilled their promise as progression-free survival from the best combinations ranges between 3 and 7 months and overall survival between 8 and 11 months. The development of targeted therapies in gastric cancer clearly stays behind the integration of these novel agents into new treatment concepts for patients with colorectal cancer. This review summarizes the experience and major recent advances in the development of targeted therapies in advanced gastric cancer.

RECENT FINDINGS

Recent publications on targeted therapies in gastric cancer are limited to nonrandomized phase I or II trials. The majority of agents tested were angiogenesis inhibitors or agents targeting the epidermal growth factor receptors epidermal growth factor receptor 1 and HER2.

SUMMARY

Adequately powered, randomized phase III trials are necessary to define the clinical role of targeted therapies in advanced gastric cancer. Biomarker studies to correlate with treatment outcomes will be critical to identify patients who benefit most from chemotherapy and targeted therapy.

Prognostic significance of the expression of vascular endothelial growth factors A, B, C, and D and their receptors R1, R2, and R3 in patients with nonsmall cell lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer death in the world. The objective of this study was to investigate the expression of vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) in patients with nonsmall cell lung cancer (NSCLC) and its correlation with the prognosis for patients with lung cancer.

METHODS

The expression status of VEGFs and VEGFRs was examined in 48 nonconsecutive specimens of primary lung cancer by immunohistochemistry. Correlations between the expression of VEGFs and VEGFRs and clinicopathologic parameters were analyzed.

RESULTS

Nineteen of 48 samples (39.6%) were moderately/highly immunoreactive for VEGF-A, 6 samples (12.5%) were reactive for VEGF-B, 14 samples (29.2%) were reactive for VEGF-C, 11 samples (22.9%) were reactive for VEGF-D, 20 samples (41.7%) were reactive for VEGFR1, 26 samples (54.2%) were reactive for VEGFR2, 20 samples (41.7%) were reactive for VEGFR3, and 19 samples (39.6%) were reactive for nuclear expression of VEGFR3. Patients with moderate/high VEGF-C, VEGFR1, and VEGFR2 expression had worse survival, whereas patients with moderate/high VEGF-D and nuclear VEGFR3 expression had better survival. After adjusting according to tumor stage, VEGF-B and VEGF-D expression had a significant correlation with worse survival in patients with stage I and II disease. Patients with stage III and IV disease who had VEGFR1 and VEGFR2 expression had worse survival, whereas the expression of VEGF-D was correlated significantly with better survival. Finally, stage, VEGF-D expression, and VEGFR1 expression were significantly independent prognostic predictors.

CONCLUSIONS

The results of the current study indicated that the over-expression of VEGFs and VEGFRs plays an important role in the survival of patients with NSCLC. The inclusion of angiogenic factors in the standard pathologic study of lung cancer may improve the clinical evaluation of patients with NSCLC.

VEGF-D expression correlates with colorectal cancer aggressiveness and is downregulated by cetuximab

AIM: To gain mechanistic insights into the role played by epidermal growth factor receptor (EGFR) in the regulation of vascular endothelial growth factors (VEGFs) in colorectal cancer (CRC).

METHODS: The impact of high-level expression of the growth factor receptors EGFR and VEGF receptor (VEGFR)3 and the VEGFR3 ligands VEGF-C and VEGF-D on disease progression and prognosis in human CRC was investigated in 108 patients using immunohistochemistry. Furthermore, the expression of the lymphangiogenic factors in response to the modulation of EGFR signalling by the EGFR-targeted monoclonal antibody cetuximab was investigated at the mRNA and protein level in human SW480 and SW620 CRC cell lines and a mouse xenograft model.

RESULTS: Human CRC specimens and cell lines displayed EGFR, VEGF-C and VEGF-D expression with varying intensities. VEGF-C expression was associated with histological grade. Strong expression of VEGF-D was significantly associated with lymph node metastases and linked to a trend for decreased survival in lymph node-positive patients. EGFR blockade with cetuximab resulted in a significant decrease of VEGF-D expression in vitro and in vivo.

CONCLUSION: In conclusion, the expression of VEGF-D in colorectal tumours is significantly associated with lymphatic involvement in CRC patients and such expression might be blocked effectively by cetuximab.