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Featured researches published by George Kouvatseas.


Annals of Oncology | 2001

Randomized comparison of early versus late hyperfractionated thoracic irradiation concurrently with chemotherapy in limited disease small-cell lung cancer: A randomized phase II study of the Hellenic Cooperative Oncology Group (HeCOG)

D. Skarlos; E. Samantas; Evangelos Briassoulis; Panoussaki E; N. Pavlidis; H. P. Kalofonos; Dimitrios Kardamakis; Tsiakopoulos E; P. Kosmidis; Dimitrios Tsavdaridis; John Tzitzikas; Periklis Tsekeris; George Kouvatseas; Nikolaos Zamboglou; George Fountzilas

BACKGROUND Concurrent platinum etoposide chemotherapy given in combination with hyperfractionated thoracic radiation therapy (HTRT) in limited disease (LD) small cell lung cancer (SCLC) is associated with a high response rate and significant prolongation of survival. Given these results, the Hellenic Cooperative Oncology Group (HeCOG) performed a multicenter randomized phase II study in patients with LD SCLC to evaluate the timing of HTRT (early vs. late) when given concurrently with chemotherapy. PATIENTS AND METHODS To be eligible for the study, patients were required to have histologically or cytologically proven LD SCLC, confined to one hemithorax and/or ipsilateral mediastinal or supraclavicular lymphnodes and absence of pleural effusion or controlateral supraclavicular lymphnode involvement. Moreover, patients had to have a good performance status and adequate haematological, liver and renal function. Patients with LD SCLC were randomized to receive HTRT either concurrently with the first (Group A) or with the fourth (Group B) cycle of chemotherapy. Chemotherapy consisted of carboplatin administered at an AUC of six given as an i.v. 1-hour-infusion immediately followed by etoposide at a dose of 100 mg/m2 i.v. as a two-hour infusion for three consecutive days every three weeks up to a total of six cycles. Prophylactic cranial irradiation was also given to patients achieving a complete response. RESULTS 42 and 39 patients, were eligible for efficacy evaluation in group A and B respectively. The overall response rate was 76% in group A and 92.5% in group B (P = 0.07) with a complete response rate of 40.5% and 56.5%, respectively. After a median follow-up of 35 months, time to progression was 9.5 months in group A and 10.5 in group B (NS) while overall median survival was 17.5 and 17 months respectively (NS). The 2-year survival was 36% in group A and 29% in group B (NS) and the 3-year survival 22% and 13%, respectively (NS). The distant relapse rate was 38% in group A and 61% in group B (P = 0.046). Severe grade 3 4 anemia was recorded in 19% of group A and 12.5% of group B (NS), while severe leucopenia was recorded in 35.5% and 20.5% (P = 0.09) and neutropenic fever in 5% and 2.5% (NS), respectively. Severe thrombocytopenia did not differ significantly between the two treatment groups being 21.5% and 23%, respectively. Severe grade 2-3 esophageal toxicity was 19% in group A and 23% in group B (NS), while grade 3 lung toxicity was 5% and 7.5% (NS), respectively. No toxicity-related deaths were recorded. CONCLUSION Concurrent administration of HTRT with carboplatin etoposide is associated with a high response and survival rate. Although a trend for higher response rate was recorded in the group of patients who received late HTRT, the overall median, 2-year and 3-year survival rates did not differ significantly between the two treatment groups. The toxicity of this promising therapeutic approach was acceptable. Comparative phase III studies with an adequate number of patients are recommended in order to answer this question.


BMC Cancer | 2013

Biomarkers of benefit from cetuximab-based therapy in metastatic colorectal cancer: interaction of EGFR ligand expression with RAS/RAF, PIK3CA genotypes

George Pentheroudakis; Vassiliki Kotoula; Wendy De Roock; George Kouvatseas; Pavlos Papakostas; Thomas Makatsoris; Demetris Papamichael; Ioannis Xanthakis; Joseph Sgouros; Despina Televantou; Georgia Kafiri; Athanassios C. Tsamandas; Evangelia Razis; Eleni Galani; Dimitrios Bafaloukos; Ioannis Efstratiou; Iliada Bompolaki; Dimitrios Pectasides; Nicholas Pavlidis; Sabine Tejpar; George Fountzilas

BackgroundMore than half of patients with KRAS-wild type advanced colorectal cancer (CRC) fail anti-EGFR monoclonal antibodies. We studied EGFR-axis messenger RNA (mRNA) expression and RAS, RAF, PIK3CA mutations in order to identify additional biomarkers of cetuximab efficacy.MethodsPreviously genotyped (KRAS, NRAS, BRAF, PIK3CA mutations) formalin-fixed paraffin-embedded tumour biopsies of 226 cetuximab-treated CRC patients (1st to 3rd line therapy) were assessed for mRNA expression of epidermal growth factor receptor (EGFR) and its ligands EGF, Transofrming Growth Factor-a (TGFA), Amphiregulin (AREG) and Epiregulin (EREG) with real time quantitative PCR. Mutations were detected in 72 (31.9%) tumours for KRAS, in 6 (2.65%) for BRAF, in 7 (3.1%) for NRAS and in 37 (16.4%) for PIK3CA.ResultsOnly PIK3CA mutations occasionally coexisted with other gene mutations. In univariate analysis, prognostic significance for survival ( from metastases until death) was seen for BRAF mutations (Hazard Ratio HR 8.1, 95% CI 3.4-19), codon 12-only KRAS mutations (HR 1.62, 95% CI 1.1-2.4), high AREG mRNA expression only in KRAS wild type CRC (HR 0.47, 95% CI 0.3-0.7) and high EREG mRNA expression irrespective of KRAS mutation status (HR 0.45, 95% CI 0.28-0.7). EREG tumoural mRNA expression was significantly associated with a 2.26-fold increased likelihood of objective response to cetuximab therapy (RECIST 1.1). In multivariate analysis, favourable predictive factors were high AREG mRNA in KRAS wild type tumours, high EREG mRNA, low Ephrin A2 receptor mRNA. Cetuximab-treated patients with AREG-low KRAS wild type CRC fared very poorly, their survival being similar to KRAS mutant CRC. Patients with KRAS codon 13 or other non-codon 12 mutations had a median survival (30 months, 95% CI 20–35) similar to that of patients with KRAS wild-type (median survival 29 months, 95% CI 25–35), in contrast to patients with KRAS codon 12 mutations who fared worse (median survival 19 months, 95% CI 15–26).ConclusionsBRAF and codon 12 KRAS mutations predict for adverse outcome of CRC patients receiving cetuximab. AREG mRNA reflects EGFR signalling in KRAS wild type tumours, predicting for cetuximab efficacy when high and failure when low. EREG may have a prognostic role independent of KRAS mutation.


Oncology | 2000

Anthracycline-Based Chemotherapy of Primary Non-Hodgkin’s Lymphoma of the Testis: The Hellenic Cooperative Oncology Group Experience

D. Pectasides; T. Economopoulos; George Kouvatseas; Antonis C. Antoniou; Z. Zoumbos; G. Aravantinos; Constantinos Tsatalas; A. Halikia; C. Nikolaides; Ch. Kiamouris; E. Pappa; N. Pavlidis; D. Skarlos; George Fountzilas; M. A. Dimopoulos

Testicular non-Hodgkin’s lymphoma is an uncommon disease and its outcome following chemotherapy and/or radiotherapy has been variable. A retrospective analysis was performed on 26 patients with primary testicular lymphoma treated predominantly with anthracycline-based chemotherapy between 1984 and 1999. The patients’ median age was 60 years (range 19–82 years) with 17 (65.4%) patients being older than 60 years. Four (15.4%) patients had constitutional B symptoms. There were 11 (42.3%) patients with high grade lymphoma, 12 (46.2%) with intermediate grade, 1 (3.8%) with low grade and 2 (7.7%) were not classified. According to the Ann-Anbor staging system, 18 patients (69.2%) had early (stage I/II) and 8 (30.8%) advanced (stage III/IV) disease. Chemotherapy was administered to 24 patients including 22 patients who received anthracycline-based chemotherapy. Two stage IEA patients were treated with orchidectomy and adjuvant radiotherapy to the regional lymph nodes without systemic chemotherapy. Chemotherapy alone resulted in a complete remission (CR) in 14 (58.3%) of 24 patients and partial remission in 1 (4.2%), amounting to an overall response rate (RR) of 62.5%. Of the 5 stage I patients who had chemotherapy on an adjuvant basis, 4 (80%) had CR/no evidence of disease. Of the 11 stage II patients, 8 (72.7%) achieved CR and 1 (9.1%) PR (overall RR of 81.8%). CR was obtained in 2 (25%) of 8 stage III/IV patients. Both patients remain disease free for 26 and 65 months. Excluding the 5 stage I patients, chemotherapy resulted in a CR in 10/19 (52.6%) patients and a PR in 1/19 (5.2%), inducing an overall RR of 57.8%. The mean duration of response was 75 months (range 8–145.5+ months). After a median follow-up of 87 months (range 0.13–145.5+ months) the median survival time was 31 months (range 0.13–145.5+ months) and the median time to progression (TTP) 17 months (range 0.13–145.5+ months). The median TTP was significantly higher in early disease compared to that of advanced disease (52 vs. 3 months, p = 0.02). Of the 3 patients who relapsed following disease-free status, CNS involvement occurred in 2 stage II patients and contralateral testis involvement in 1 stage IEA, respectively. The latter remained disease free for 2 years following orchidectomy alone. The other 2 patients who relapsed did not respond to salvage chemotherapy and died. There was no significant relationship between the values of LDH and β2-microglobulin with the outcome except for ESR which was significantly related with the CR (p = 0.005) or RR (p = 0.005). In conclusion, patients with primary testicular lymphoma have a poor outcome, despite the treatment with anthracycline-containing regimens. Treatment with anthracycline-based chemotherapy is recommended in patients at early stages. In advanced disease, more intensive or investigational regimens should be considered. Because the relapse rate in the CNS and contralateral testis is quite high in most studies, prophylactic CNS treatment and radiotherapy to the other testis should be included in the management of testicular lymphoma.


Breast Cancer Research | 2012

The prognostic and predictive value of mRNA expression of vascular endothelial growth factor family members in breast cancer: a study in primary tumors of high-risk early breast cancer patients participating in a randomized Hellenic Cooperative Oncology Group trial.

Helena Linardou; Konstantine T. Kalogeras; Ralf Kronenwett; George Kouvatseas; Ralph M. Wirtz; Flora Zagouri; Helen Gogas; Christos Christodoulou; Angelos Koutras; Epaminondas Samantas; Dimitrios Pectasides; Dimitrios Bafaloukos; George Fountzilas

IntroductionThe main prognostic variables in early breast cancer are tumor size, histological grade, estrogen receptor/progesterone receptor (ER/PgR) status, number of positive nodes and human epidermal growth factor receptor 2 (HER2) status. The present study evaluated the prognostic and/or predictive value of vascular endothelial growth factor (VEGF) family members in high-risk early breast cancer patients treated with adjuvant chemo-hormonotherapy.MethodsRNA was isolated from 308 formalin-fixed paraffin-embedded primary tumor samples from breast cancer patients enrolled in the HE10/97 trial, evaluating adjuvant dose-dense sequential chemotherapy with epirubicin followed by cyclophosphamide, methotrexate, fluorouracil (CMF) with or without paclitaxel (E-T-CMF versus E-CMF). A fully automated method based on magnetic beads was applied for RNA extraction, followed by one-step quantitative RT-PCR for mRNA analysis of VEGF-A, -B, -C and vascular endothelial growth factor receptor (VEGFR) 1, 2, 3.ResultsWith a median follow-up of 8 years, 109 patients (35%) developed a relapse and 80 patients (26%) died. In high VEGF-C and VEGFR1 mRNA expressing tumors, ER/PgR-negative tumors (Fishers exact test, P = 0.001 and P = 0.021, respectively) and HER2-positive tumors (P <0.001 and P = 0.028, respectively) were more frequent than in low VEGF-C and VEGFR1 expressing tumors, respectively. From the VEGF family members evaluated, high VEGFR1 mRNA expression (above the 75th percentile) emerged as a significant negative prognostic factor for overall survival (OS; hazard ratio (HR) = 1.60, 95% confidence interval (CI): 1.01 to 2.55, Walds P = 0.047) and disease-free survival (DFS; HR = 1.67, 95% CI: 1.13 to 2.48, P = 0.010), when adjusting for treatment group. High VEGF-C mRNA expression was predictive for benefit from adjuvant treatment with paclitaxel (E-T-CMF arm) for OS (test for interaction, Walds P = 0.038), while in multivariate analysis the interaction of VEGF-C with taxane treatment was significant for both OS (Walds P = 0.019) and DFS (P = 0.041) and continuous VEGF-B mRNA expression values for OS (P = 0.019).ConclusionsThe present study reports, for the first time, that VEGF-C mRNA overexpression, as assessed by qRT-PCR, has a strong predictive value in high-risk early breast cancer patients undergoing adjuvant paclitaxel-containing treatment. Further studies are warranted to validate the prognostic and/or predictive value of VEGF-B, VEGF-C and VEGFR1 in patients treated with adjuvant therapies and to reveal which members of the VEGF family could possibly be useful markers in identifying patients who will benefit most from anti-VEGF strategies.Trial registrationAustralian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12611000506998


Clinical Colorectal Cancer | 2013

The prognostic role of ephrin A2 and endothelial growth factor receptor pathway mediators in patients with advanced colorectal cancer treated with cetuximab.

Alexios Strimpakos; George Pentheroudakis; Vassiliki Kotoula; Wendy De Roock; George Kouvatseas; Pavlos Papakostas; Thomas Makatsoris; Demetris Papamichael; Anna Andreadou; Joseph Sgouros; Adamantia Zizi-Sermpetzoglou; Athina Kominea; Despina Televantou; Evangelia Razis; Eleni Galani; Dimitrios Pectasides; Sabine Tejpar; Konstantinos Syrigos; George Fountzilas

BACKGROUND Patients with colorectal cancer (CRC) with wild-type KRAS mutations are often treated with the endothelial growth factor receptor (EGFR) monoclonal antibody cetuximab. Despite the presence of a specific molecular target, most patients still do not derive benefit from this biological treatment. Our study explores the role of ephrin A2 (EphA2) receptor expression and of EGFR pathway mediators as predictors of cetuximab benefit. PATIENTS AND METHODS Formalin-fixed paraffin-embedded (FFPE) tumor biopsy samples from 226 cetuximab-treated patients with CRC were studied for mRNA expression of insulin growth factor binding protein 2 (IGFBP2), insulin growth factor receptor 1 (IGF1R), cMET, EphA2, human epidermal growth factor receptor 2 (HER2), HER3, and HER4 by means of TaqMan reverse-transcribed polymerase chain reaction (RT-PCR). RESULTS Of the 226 patients evaluable for exploratory analysis, 222 had complete data from follow-up visits. The univariate analysis revealed the following significant adverse prognostic factors for risk of death: high EphA2 mRNA levels (hazard ratio [HR], 1.61; P = .015), high HER2 mRNA levels (HR, 1.51; P = .045), and high IGF1R mRNA levels (HR, 1.56; P = .021). Low EphA2 tumor expression was significantly associated with objective response to cetuximab therapy. In multivariate analysis of a broad biomarker panel, factors with independent prognostic value included EphA2 mRNA levels (HR, 1.67; P = .029), high amphiregulin (AREG) mRNA levels in KRAS wild-type tumors (HR, 0.17; P < .0001), and high epiregulin (EREG) mRNA levels (HR, 0.38; P = .006). CONCLUSION High EphA2 receptor expression in CRC was associated with a worse outcome in patients treated with cetuximab-based therapy. Prospective validation in treated and control patients is required to dissect the predictive from prognostic role in advanced CRC.


Cancer Investigation | 2003

A Phase II Study with CPT-11 Plus Leucovorin and Bolus IV 5-Fluorouracil in Patients with Advanced Colorectal Carcinoma

H. P. Kalofonos; D. Skarlos; D. Bafaloukos; Pavlos Papakostas; Aristotle Bamias; Jim Janinis; Eleni Timotheadou; George Kouvatseas; Michalis Stavropoulos; T. Economopulos; George Fountzilas

Standard chemotherapy in advanced colorectal carcinoma (CRC) has not yet been established. The present study was conducted to assess the efficacy and toxicity profile of CPT-11, leucovorin (LV), and bolus 5-fluorouracil (5-FU) in a weekly schedule. Fifty-five patients were entered with no prior chemotherapy for advanced disease or adjuvant treatment ended at least 6 months preceding study entry, and 45 were assessable for response. Patients were treated with CPT-11 80 mg/m2 (7 patients) or 70 mg/m2 (48 patients). After completion of CPT-11 infusion, LV 200 mg/m2 was administered over 2 hr followed immediately by 5-FU 450 mg/m2, IV bolus, weekly for 6 weeks followed by a 2-week rest period. Treatment was continued for four cycles. Because of grade 3 and 4 diarrhea in four of the first seven patients, the study was amended to reduce the starting dose of CPT-11 from 80 to 70 mg/m2 weekly. Four complete and 10 partial responses were observed (response rate: 25.5%), the median time to progression (TTP) was 7.7 months, 1-year survival rate was 62.3%, and the median overall survival was 15.0 months. Grade 3 and 4 diarrhea occurred in seven patients (12.7%), four of them treated with CPT-11 80 mg/m2. Grade 3 myelotoxicity occurred in five patients (9.0%). Toxic death because of diarrhea, neutropenia, bacteremia, and sepsis occurred in a patient treated with CPT-11 80 mg/m2. Our results confirm the efficacy of CPT-11, LV, and 5-FU in a weekly schedule in patients with advanced CRC. Further studies are needed to compare the present regimen with higher doses of CPT-11 with LV plus different schedules of 5-FU administration in the treatment of metastatic CRC.


PLOS ONE | 2014

Differential Expression of the Insulin-Like Growth Factor Receptor among Early Breast Cancer Subtypes

Giannis Mountzios; Dimitra Aivazi; Ioannis Kostopoulos; Helen P. Kourea; George Kouvatseas; Eleni Timotheadou; Pantelis Zebekakis; Ioannis Efstratiou; Helen Gogas; Chrisanthi Vamvouka; Sofia Chrisafi; Anastasios Stofas; George Pentheroudakis; Angelos Koutras; Eleni Galani; Dimitrios Bafaloukos; George Fountzilas

Introduction We sought to determine the level of protein expression of the critical components of the insulin-like growth factor receptor (IGFR) pathway and to evaluate their prognostic significance across the different early breast cancer subtypes. Patients and Methods Archival tumor tissue from 1,021 women with early, node positive breast cancer, who were prospectively evaluated within two randomized clinical trials, was used to construct tissue microarrays that were stained for hormone receptors (HR), Ki67, HER2, epidermal growth factor receptor (EGFR) and cytokeratins 5/6, to classify tumors into five immunophenotypical subgroups. Immunohistochemical (IHC) expression of IGF1R-alpha and beta subunits, IGF2R and IGF-binding protein 2 (IGFBP2) was assessed using the immunoreactive score (IRS). Repeated internal cross-validation was performed to examine the statistical validity of the cut off points for all biomarkers. Results After a median follow-up time of 105.4 months, overall 370 women (36.2%) had relapsed and 270 (26.4%) had died. Tumors expressing IGF1R-alpha above the median IRS were significantly more frequently HR positive (luminal A+B+HER2), as compared to HER2-enriched and triple negative ones (p<0.001 for both comparisons). IGF2R was overexpressed significantly more frequently in HR negative tumors (p = 0.001) and had an inverse correlation with all other biomarkers. Patients with luminal A and B tumors with high IGF1R-alpha and negative EGFR expression (N = 190) had significantly higher 4-year survival rates, as compared to the rest (log-rank p = 0.046), as did patients with luminal A and B tumors with high IGF1R-alpha and low IGF2R expression, as compared to the rest (N = 91), (log-rank p = 0.035). After adjustment for significant variables, patients in the latter group had a relative 45% reduction in the risk of death, as compared to the rest (p = 0.035). Conclusion Aberrant expression of components of the IGF1R pathway is associated with better clinical outcomes in women with luminal A and B, node positive, early breast cancer.


PLOS ONE | 2013

Ixabepilone Administered Weekly or Every Three Weeks in HER2-Negative Metastatic Breast Cancer Patients; A Randomized Non-Comparative Phase II Trial

George Fountzilas; Vassiliki Kotoula; Dimitrios Pectasides; George Kouvatseas; Eleni Timotheadou; Mattheos Bobos; Xanthipi Mavropoulou; Christos Papadimitriou; Eleni Vrettou; Georgia Raptou; Angelos Koutras; Evangelia Razis; Dimitrios Bafaloukos; E. Samantas; George Pentheroudakis; Dimosthenis Skarlos

To explore the activity and safety of two schedules of ixabepilone, as first line chemotherapy, in patients with metastatic breast cancer previously treated with adjuvant chemotherapy, a randomized non-comparative phase II study was conducted. From November 2008 until December 2010, 64 patients were treated with either ixabepilone 40 mg/m2 every 3 weeks (Group A, 32 patients) or ixabepilone 20 mg/m2 on days 1, 8 and 15 every 4 weeks (Group B, 32 patients). Overall response rate (the primary end point) was 47% in Group A and 50% in Group B. The most frequent severe adverse events were neutropenia (32% vs. 23%), metabolic disturbances (29% vs. 27%) and sensory neuropathy (12% vs. 27%). Two patients in Group A and 3 in Group B developed febrile neutropenia. After a median follow-up of 22.7 months, median progression-free survival (PFS) was 9 months in Group A and 12 months in Group B. Median survival was 26 months in Group A, whereas it was not reached in Group B. Multiple genetic and molecular markers were examined in tumor and peripheral blood DNA, but none of them was associated with ORR or drug toxicity. Favorable prognostic markers included: the T-variants of ABCB1 SNPs c.2677G/A/T, c.1236C/T and c.3435C/T, as well as high MAPT mRNA and Tau protein expression, which were all associated with the ER/PgR-positive phenotype; absence of TopoIIa; and, an interaction between low TUBB3 mRNA expression and Group B. Upon multivariate analysis, tumor ER-positivity was a favorable (p = 0.0092) and TopoIIa an unfavorable (p = 0.002) prognostic factor for PFS; PgR-positivity was favorable (p = 0.028) for survival. In conclusion, ixabepilone had a manageable safety profile in both the 3-weekly and weekly schedules. A number of markers identified in the present trial appear to deserve further evaluation for their prognostic and/or predictive value in larger multi-arm studies. Trial Registration ClinicalTrials.gov NCT 00790894


Clinical and Experimental Pharmacology | 2012

Expression of Notch Receptors in Primary Breast Cancer and Correlation with Pathological Features

Panagiota Touplikioti; Dafni Chondronasiou; Fani Ziouti; Melanie Koubanaki; Konstantinos Haitoglou; George Kouvatseas; Konstantinos Papazisis

Introduction: Notch signaling evolves as an important mediator of stem cell biology, tumor formation, angiogenesis and cell fate decisions. Four Notch receptors and five ligands have been identified in human, and they regulate a complex signal transduction pathway that interacts with other stem cell-related pathways as Sonic Hedgehog and Wnt. Recently, dysregulation of Notch pathway has been found to play a crucial role in breast cancer oncogenesis and it could serve as a target for treatment. Methods: We estimated the expression of Notch receptors’ at the mRNA level, in 200 human breast cancer samples from a single institution in Northern Greece. Notch 1-4 mRNA was estimated by using Real-time PCR and we correlated the level of Notch expression with breast cancer pathology (TNM, grade oestrogen and progesterone receptors and HER2). Results: We found that Notch receptors (at the mRNA level) are differentially expressed in breast cancer subgroups. Hormone receptor positive cancers express Notch-4 whilst Notch-1 and Notch-3 receptors are involved in the development of triple-negative breast cancer. HER2-positive cancers express lower levels of Notch-1, a finding that is in concert with other reports as well. Conclusion: Notch receptors are expressed differentially and could serve as potential targets for treatment in different molecular subtypes of breast cancer.


Clinical Breast Cancer | 2014

Association of VEGF-A Splice Variant mRNA Expression With Outcome in Bevacizumab-Treated Patients With Metastatic Breast Cancer

George Pentheroudakis; Vassiliki Kotoula; George Kouvatseas; Elpida Charalambous; Dimitrios Dionysopoulos; Flora Zagouri; Angelos Koutras; Konstantinos Papazisis; Dimitrios Pectasides; E. Samantas; Meletios A. Dimopoulos; Christos Papandreou; George Fountzilas

BACKGROUND The prognostic utility of vascular endothelial growth factor A (VEGF-A) splice variants in patients with advanced breast cancer treated with bevacizumab has not been studied. PATIENTS AND METHODS A total of 111 patients with metastatic breast cancer treated with weekly docetaxel or ixabepilone without bevacizumab (cohort A) and 100 treated with weekly paclitaxel and bevacizumab (cohort B) were studied. Formalin-fixed tumors were macrodissected for reverse transcription quantitative polymerase chain reaction relative quantification of VEGF-A165, -189, and -206 isoforms spliced at exon 8 proximal splice site (VEGF-Axxxa) and at exon 8 distal splice site (VEGF-Axxxb). RESULTS For high VEGF-Axxxa, the hazard ratios (HRs) for progression were 1.08 (P = .71) in non-bevacizumab-treated patients (cohort A) and 0.66 (P = .22) in bevacizumab-treated patients (cohort B), and the HRs for death were 1.45 (P = .13) and 0.50 (P = .049), respectively. The interaction of VEGF-Axxxa with bevacizumab administration was significant (P = .011) for overall survival (OS). High tissue VEGF-Axxxb was not prognostic in cohort A but was predictive for bevacizumab benefit in cohort B (HR for progression, 0.57 [P = .04]; HR for death, 0.51 [P = .02]). Exploratory analyses done only in cohort B suggested that abundance of VEGFR1 messenger RNA (mRNA) in peripheral blood and low VEGFR2 mRNA in tissue correlated with poor outcome. In multivariate analysis, high tissue mRNA of angiogenic VEGF-Axxxa in the presence of bevacizumab therapy predicted for favorable progression-free survival (HR for progression, 0.39; P = .0227) and OS (HR for death, 0.32; P = .0140). CONCLUSION Tissue mRNA expression of angiogenic VEGF-Axxxa isoforms was retrospectively associated with adverse prognosis in the absence of bevacizumab and with favorable outcome when bevacizumab was administered in patients with advanced breast cancer.

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George Fountzilas

Aristotle University of Thessaloniki

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Vassiliki Kotoula

Aristotle University of Thessaloniki

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E. Samantas

University of Ioannina

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Pavlos Papakostas

National and Kapodistrian University of Athens

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Dimitrios Pectasides

National and Kapodistrian University of Athens

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Christos Christodoulou

Aristotle University of Thessaloniki

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Mattheos Bobos

Aristotle University of Thessaloniki

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