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Dive into the research topics where Dimitris Mavroudis is active.

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Featured researches published by Dimitris Mavroudis.


Journal of Clinical Oncology | 2002

Molecular Detection of Cytokeratin-19–Positive Cells in the Peripheral Blood of Patients With Operable Breast Cancer: Evaluation of Their Prognostic Significance

A. Stathopoulou; I. Vlachonikolis; Dimitris Mavroudis; M. Perraki; Ch. Kouroussis; S. Apostolaki; N. Malamos; S. Kakolyris; A. Kotsakis; N. Xenidis; D. Reppa; V. Georgoulias

PURPOSE To evaluate the prognostic significance of molecular detection of cytokeratin 19 (CK-19) mRNA-positive cells by nested reverse transcriptase polymerase chain reaction (RT-PCR) in the peripheral blood of women with stages I and II breast cancer before adjuvant chemotherapy. PATIENTS AND METHODS The sensitivity and specificity of CK-19 mRNA detection by nested RT-PCR were investigated using MCF-7 and ARH-77 cells and blood from healthy women and patients with hematologic malignancies, metastatic colorectal cancer, and early and metastatic breast cancer. Peripheral blood from 148 patients with operable breast cancer, obtained before initiation of any adjuvant therapy, was tested for the presence of CK-19 mRNA-positive cells. RESULTS The nested RT-PCR assay for CK-19 mRNA detected one MCF-7 tumor cell in 10(6) normal peripheral blood mononuclear cells in four of five experiments; no signal was detected with the CK-19-negative ARH-77 cells. CK-19 mRNA was detected in the peripheral blood of 3.7% of healthy blood donors, 14.3% of patients with hematologic malignancies, and 3.2% of patients with metastatic colorectal cancer. Detection rates for CK-19 mRNA-positive cells in the bone marrow/blood of patients with early or metastatic breast cancer were 63%/30% and 74%/52%, respectively. For stages I and II breast cancer, detection of CK-19-positive cells in the peripheral blood before adjuvant therapy was associated with reduced disease-free interval (P =.0007) and overall survival (P =.01). In multivariate analysis, detection of peripheral-blood CK-19-positive cells was an independent prognostic factor for disease relapse and death. CONCLUSION Molecular detection of CK-19 mRNA-positive cells by RT-PCR in the peripheral blood of patients with stages I and II breast cancer before initiation of adjuvant therapy has independent prognostic value as a marker of poor clinical outcome.


British Journal of Cancer | 2006

FOLFOXIRI (folinic acid, 5-fluorouracil, oxaliplatin and irinotecan) vs FOLFIRI (folinic acid, 5-fluorouracil and irinotecan) as first-line treatment in metastatic colorectal cancer (MCC): a multicentre randomised phase III trial from the Hellenic Oncology Research Group (HORG)

John Souglakos; N. Androulakis; K. Syrigos; A. Polyzos; N Ziras; Apostolos Athanasiadis; S. Kakolyris; S. Tsousis; Ch Kouroussis; L. Vamvakas; A. Kalykaki; G. Samonis; Dimitris Mavroudis; V. Georgoulias

To compare the efficacy and toxicity of oxaliplatin (L-OHP) in combination with irinotecan (CPT-11), 5-fluorouracil (5-FU) and leucovorin (LV) (FOLFOXIRI) vs irinotecan and 5-FU/LV (FOLFIRI) as first-line treatment of patients with metastatic colorectal cancer (MCC). A total of 283 chemotherapy-naïve patients with MCC were enrolled (FOLFIRI arm: n=146; FOLFOXIRI arm: n=137). In the FOLFOXIRI arm, CPT-11 (150 mg m−2) was given on d1, L-OHP (65 mg m−2) on d2, LV (200 mg m−2) on days 2 and 3 and 5-FU (400 mg m−2 as i.v. bolus and 600 mg m−2 as 22 h i.v. continuous infusion) on days 2 and 3. In the FOLFIRI arm, CPT-11 (180 mg m−2) was given on d1 whereas LV and 5-FU were administered in the same way as in the FOLFOXIRI regimen. Both regimens were administered every 2 weeks. There was no difference in terms of overall survival (median OS: 19.5 and 21.5 months, for FOLFIRI and FOLFOXIRI, respectively; P=0.337), median time to disease progression (FOLFIRI: 6.9 and FOLFOXIRI: 8.4 months; P=0.17), response rates (33.6 and 43% for FOLFIRI and FOLFOXIRI, respectively; P=0.168). Patients treated with FOLFOXIRI had a significantly higher incidence of alopecia (P=0.0001), diarrhoea (P=0.0001) and neurosensory toxicity (P=0.001) compared with patients treated with FOLFIRI. The present study failed to demonstrate any superiority of the FOLFOXIRI combination compared with the FOLFIRI regimen, although the observed median OS is one of the best ever reported in the literature.


Breast Cancer Research | 2011

Epithelial to mesenchymal transition markers expressed in circulating tumour cells of early and metastatic breast cancer patients

Galatea Kallergi; Maria Papadaki; Eleni Politaki; Dimitris Mavroudis; Vassilis Georgoulias; S. Agelaki

IntroductionEpithelial to mesenchymal transition (EMT) is considered an essential process in the metastatic cascade. EMT is characterised by upregulation of vimentin, Twist, Snail, Slug and Sip1 among others. Metastasis is also associated with the presence of circulating tumour cells (CTCs) and disseminated tumour cells in the blood and bone marrow, respectively, of breast cancer patients, but the expression of EMT markers in these cells has not been reported so far.MethodsThe expression of Twist and vimentin in CTCs of 25 metastatic and 25 early breast cancer patients was investigated by using double-immunofluorescence experiments in isolated peripheral blood mononuclear cell cytospins using anti-cytokeratin (anti-CK) anti-mouse (A45-B/B3) and anti-Twist or anti-vimentin anti-rabbit antibodies.ResultsAmong early breast cancer patients, vimentin-and Twist-expressing CK+ CTCs were identified in 77% and 73% of the patients, respectively, and in 100% of the patients with metastatic breast cancer for both markers (P = 0.004 and P = 0.037, respectively). Among patients with early disease, 56% and 53% of the CK+ CTCs were double-stained with vimentin and Twist, and the corresponding values for metastatic patients were 74% and 97%, respectively (P = 0.005 and P = 0.0001, respectively). The median expression of CK+vimentin+ and CK+Twist+ cells per patient in metastatic patients was 98% and 100%, and in an adjuvant chemotherapy setting the corresponding numbers were 56% and 40.6%, respectively. Triple-staining experiments revealed that all CK+Twist+ or CK+vimentin+ cells were also CD45-, confirming their epithelial origin. Immunomagnetic separation of CTCs and triple-immunofluorescence with anti-CK/anti-Twist/anti-vimentin antibodies demonstrated that both mesenchymal markers could be coexpressed in the same CK+ cell, since 64% of the total identified CTCs were triple-stained. There was a significant correlation (P = 0.005) between the number of CTCs expressing Twist and vimentin within the same setting.ConclusionsCTCs expressing Twist and vimentin, suggestive of EMT, are identified in patients with breast cancer. The high incidence of these cells in patients with metastatic disease compared to early stage breast cancer strongly supports the notion that EMT is involved in the metastatic potential of CTCs.


Journal of Clinical Oncology | 2009

Cytokeratin-19 mRNA-Positive Circulating Tumor Cells After Adjuvant Chemotherapy in Patients With Early Breast Cancer

Nikolaos Xenidis; Michail Ignatiadis; Stella Apostolaki; Maria Perraki; Kostas Kalbakis; S. Agelaki; Efstathios N. Stathopoulos; Grigorios Chlouverakis; Evi S. Lianidou; S. Kakolyris; Vassilis Georgoulias; Dimitris Mavroudis

PURPOSE To evaluate the prognostic significance of cytokeratin-19 (CK-19) mRNA-positive circulating tumor cells (CTCs) in peripheral blood of women with early-stage breast cancer after the completion of adjuvant chemotherapy. PATIENTS AND METHODS Blood was obtained from 437 patients with early breast cancer before the start and after the completion of adjuvant chemotherapy, and the presence of CK-19 mRNA-positive CTCs was assessed by real-time reverse transcriptase polymerase chain reaction. Interaction with known prognostic factors and association of CTCs with clinical outcome were investigated. RESULTS CK-19 mRNA-positive CTCs were detected before chemotherapy in 179 patients (41.0%). After adjuvant chemotherapy, a significant change in CK-19 status was observed, as status for 51% of patients with initially CK-19 mRNA-positive disease turned negative, and status for 22% of patients with initially CK-19 mRNA-negative disease became positive (McNemar test P = .004). The detection of CK-19 mRNA-positive CTCs postchemotherapy was associated with involvement of more than three axillary lymph nodes (P = .026). Clinical relapses and disease-related deaths were significantly increased in patients with detectable postchemotherapy CK-19 mRNA-positive CTCs (both P < .001, respectively). Disease-free and overall survival were significantly reduced in patients with detectable CK-19 mRNA-positive CTCs postchemotherapy (P < .001 and P = .001, respectively). In multivariate analysis, the detection of CK-19 mRNA-positive CTCs before and after adjuvant chemotherapy was an independent factor associated with reduced disease-free survival (P < .001) and overall survival (P = .003). CONCLUSION The detection of CK-19 mRNA-positive CTCs in the blood after adjuvant chemotherapy is an independent risk factor indicating the presence of chemotherapy-resistant residual disease.


Journal of Clinical Oncology | 2007

Different Prognostic Value of Cytokeratin-19 mRNA Positive Circulating Tumor Cells According to Estrogen Receptor and HER2 Status in Early-Stage Breast Cancer

Michail Ignatiadis; Nikos Xenidis; Maria Perraki; Stella Apostolaki; Eleni Politaki; Maria Kafousi; Efstathios N. Stathopoulos; Aliki Stathopoulou; Evi S. Lianidou; Grigorios Chlouverakis; Christos Sotiriou; Vassilis Georgoulias; Dimitris Mavroudis

PURPOSE To examine the prognostic value of cytokeratin-19 (CK-19) mRNA-positive circulating tumor cells (CTCs) in early-stage breast cancer patients focusing on clinically relevant subgroups based on estrogen receptor (ER) and HER2 expression. PATIENTS AND METHODS CK-19 mRNA-positive CTCs were detected by real-time reverse transcriptase polymerase chain reaction in the blood of 444 consecutive, stage I-III, breast cancer patients before initiation of adjuvant chemotherapy. The association between detection of CK-19 mRNA-positive CTCs and clinical outcome was analyzed for patients with ER-positive, ER-negative, triple-negative, HER2-positive, and ER-positive/HER2-negative tumors. RESULTS CK-19 mRNA-positive CTCs were detected in 181 (40.8%) of 444 patients; 109 (41.9%) of 260 patients with ER-positive tumors; 71 (40.6%) of 175 patients with ER-negative tumors; 27 (35%) of 77 patients with triple-negative tumors; 35 (39.8%) of 88 patients with HER2-positive tumors; and 82 (44.1%) of 186 patients with ER-positive/HER2-negative tumors. After a median follow-up of 53.5 months, patients with CK-19 mRNA-positive CTCs experienced reduced disease-free survival (DFS; P < .001) and overall survival (OS; P < .001); this was mainly observed in patients with ER-negative (P < .001 and P < .001, respectively) but not ER-positive tumors (P = .172 and P = .425, respectively) and in patients with triple-negative (P = .008 and P = .001, respectively) and HER2-positive (P = .023 and P = .040, respectively) but not ER-positive/HER2-negative tumors (P = .210 and P = .578, respectively). In multivariate analysis, the interaction between CK-19 mRNA-positive CTCs and ER status was the strongest independent prognostic factor for reduced DFS (hazard ratio [HR], 3.808; 95% CI, 2.415 to 6.003; P < .001) and OS (HR, 4.172; 95% CI, 2.477 to 9.161; P < .001). CONCLUSION Detection of CK-19 mRNA-positive CTCs before adjuvant chemotherapy predicts poor clinical outcome mainly in patients with ER-negative, triple-negative, and HER2-positive early-stage breast cancer.


Cancer Letters | 2010

Circulating tumor cells with a putative stem cell phenotype in peripheral blood of patients with breast cancer

Panayiotis A. Theodoropoulos; Hara Polioudaki; Sofia Agelaki; Galatea Kallergi; Zacharenia Saridaki; Dimitris Mavroudis; Vassilis Georgoulias

The CD44(+)/CD24(-/low) and ALDH1(+) cell phenotypes are associated with stemness and enhanced tumorigenic potential in breast cancer. We assessed the expression of CD44, CD24 and ALDH1 on tumor cells circulating in the peripheral blood (CTCs) of patients with metastatic breast cancer using triple-marker immunofluorescence microscopy. Among a total of 1439 CTCs identified in 20 (66.7%) out of 30 patients, 35.2% had the stem-like/tumorigenic phenotype CD44(+)/CD24(-/low), whereas 17.7% of the CTCs analyzed in seven patients, were ALDH1(high)/CD24(-/low). In conclusion, we report the existence of a subpopulation of CTCs with putative stem cell progenitor phenotypes in patients with metastatic breast cancer.


Clinical Cancer Research | 2008

Prognostic Value of the Molecular Detection of Circulating Tumor Cells Using a Multimarker Reverse Transcription-PCR Assay for Cytokeratin 19, Mammaglobin A, and HER2 in Early Breast Cancer

Michail Ignatiadis; Galatea Kallergi; Maria Ntoulia; Maria Perraki; Stella Apostolaki; Maria Kafousi; Grigorios Chlouverakis; Efstathios N. Stathopoulos; Evi S. Lianidou; Vassilis Georgoulias; Dimitris Mavroudis

Purpose: To investigate the prognostic value of the molecular detection of circulating tumor cells (CTCs) using three markers [cytokeratin 19 (CK19), mammaglobin A (MGB1), and HER2] in early breast cancer. Experimental Design: CK19mRNA+, MGB1mRNA+, and HER2mRNA+ cells were detected using real-time (CK19) and nested (MGB1 and HER2) reverse transcription-PCR in the peripheral blood of 175 women with stage I to III breast cancer before the initiation of adjuvant chemotherapy. The detection of CTCs was correlated with clinical outcome. In 10 patients, immunofluorescence staining experiments were done to investigate the coexpression of cytokeratin, MGB1, and HER2 in CTCs. Results: CK19mRNA+, MGB1mRNA+, and HER2mRNA+ cells were detected in 41.1%, 8%, and 28.6% of the 175 patients, respectively. Patients had one of the following molecular profiles: CK19mRNA+/MGB1mRNA+/HER2mRNA+ (n = 8), CK19mRNA+/MGB1mRNA+/HER2mRNA− (n = 1), CK19mRNA+/MGB1mRNA−/HER2mRNA+ (n = 42), CK19mRNA+/MGB1mRNA−/HER2mRNA− (n = 21), CK19mRNA−/MGB1mRNA+/HER2mRNA− (n = 5), and CK19mRNA−/MGB1mRNA−/HER2mRNA− (n = 98). Double-immunofluorescence experiments confirmed the following CTC phenotypes: CK+/MGB1+, CK+/MGB1−, CK−/MGB1+, CK+/HER2+, CK+/HER2−, MGB1+/HER2−, and MGB1+/HER2+. In univariate analysis, the detection of CK19mRNA+, MGB1mRNA+, and HER2mRNA+ cells was associated with shorter disease-free survival (DFS; P < 0.001, P = 0.001, and P < 0.001, respectively), whereas the detection of CK19mRNA+ and MGB1mRNA+ cells was associated with worse overall survival (P = 0.044 and 0.034, respectively). In multivariate analysis, estrogen receptor–negative tumors and the detection of CK19mRNA+ and MGB1mRNA+ cells were independently associated with worse DFS. Conclusion: The detection of peripheral blood CK19mRNA+ and MGB1mRNA+ cells before adjuvant chemotherapy predicts poor DFS in women with early breast cancer.


Clinical Cancer Research | 2004

Trastuzumab Administration Can Effectively Target Chemotherapy-Resistant Cytokeratin-19 Messenger RNA–Positive Tumor Cells in the Peripheral Blood and Bone Marrow of Patients With Breast Cancer

Vassiliki Bozionellou; Dimitris Mavroudis; Maria Perraki; Savvas Papadopoulos; Stella Apostolaki; Efstathios N. Stathopoulos; Aliki Stathopoulou; Evi S. Lianidou; Vassilis Georgoulias

Purpose: The detection of disseminated occult breast cancer cells in peripheral blood and bone marrow is associated with poor prognosis. Since a high proportion of these cells express the HER-2 receptor, we evaluated the effectiveness of the anti-HER-2 antibody trastuzumab (Herceptin) administration to eliminate them. Experimental Design: Thirty patients with prior chemotherapy exposure were recruited to the study on the basis of having detectable cytokeratin-19 (CK-19) mRNA transcripts by nested reverse transcription (RT)-PCR in the peripheral blood and/or bone marrow. There were 13 patients with stage I, II, or III breast cancer and 17 with stage IV disease. They were treated in two cohorts with either 4 to 8 weekly infusions of trastuzumab at 2 mg/kg (4 mg/kg loading dose; 20 patients) or 2 to 3 infusions every 3 weeks at 6 mg/kg (8 mg/kg loading dose; 10 patients). All of the patients’ samples were also analyzed for HER-2 by nested RT-PCR, but detectable HER-2 messenger RNA (mRNA) was not required for inclusion in the study. After trastuzumab infusions, patients were closely monitored by nested RT-PCR and real-time RT-PCR for the detection of CK-19 mRNA-positive cells. Results: Before trastuzumab infusions, CK-19 mRNA-positive cells were detected in the peripheral blood (n = 10), bone marrow (n = 14), or both (n = 6). In 25 of 30 patients (83%), HER-2 mRNA expression was detected by nested RT-PCR in the pretrastuzumab CK-19–positive sample. After trastuzumab infusions, overall, 28 of 30 (93%) patients became CK-19 mRNA negative by nested RT-PCR and 20 of 30 (67%) by real-time RT-PCR. After a median follow-up of 6 months (range 2 to 22+), the median duration of CK-19 mRNA negativity by nested RT-PCR was 9, 12, and 6 months for stage I/II, III, and IV disease, respectively. Conclusions: Therapy-resistant CK-19 mRNA-positive cells in the peripheral blood and bone marrow can be effectively targeted by trastuzumab administration. Further studies are needed to evaluate the prognostic significance of the disappearance of these cells.


PLOS ONE | 2011

Impact of KRAS, BRAF, PIK3CA Mutations, PTEN, AREG, EREG Expression and Skin Rash in ≥2nd Line Cetuximab-Based Therapy of Colorectal Cancer Patients

Zacharenia Saridaki; Maria Tzardi; Chara Papadaki; Maria Sfakianaki; Fraga Pega; Aristea Kalikaki; E. Tsakalaki; Maria Trypaki; Ippokratis Messaritakis; Efstathios N. Stathopoulos; Dimitris Mavroudis; Vassilis Georgoulias; John Souglakos

Background To investigate the predictive significance of KRAS, BRAF, PIK3CA mutational status, AREG- EREG mRNA expression, PTEN protein expression and skin rash in metastatic colorectal cancer (mCRC) patients treated with cetuximab containing salvage chemotherapy. Methods Primary tumors from 112 mCRC patients were analyzed. The worst skin toxicity during treatment was recorded. Results KRAS, BRAF and PIK3CA mutations were present in 37 (33%), 8 (7.2%) and 11 (9.8%) cases, respectively, PTEN was lost in 21 (19.8%) cases, AREG and EREG were overexpressed in 48 (45%) and 51 (49%) cases. In the whole study population, time to tumor progression (TTP) and overall survival (OS) was significantly lower in patients with KRAS (p = 0.001 and p = 0.026, respectively) or BRAF (p = 0.001 and p<0.0001, respectively) mutant tumors, downregulation of AREG (p = 0.018 and p = 0.013, respectively) or EREG (p = 0.002 and p = 0.004, respectively) and grade 0-1 skin rash (p<0.0001 and p<0.0001, respectively). In KRAS wt patients TTP and OS was significantly lower in patients with BRAF (p = 0.0001 and p<0.0001, respectively) mutant tumors, downregulation of AREG (p = 0.021 and p = 0.004, respectively) or EREG (p = 0.0001 and p<0.0001, respectively) and grade 0-1 skin rash (p<0.0001 and p<0.0001, respectively). TTP was significantly lower in patients with PIK3CA mutations (p = 0.01) or lost PTEN (p = 0.002). Multivariate analysis revealed KRAS (Hazard Ratio [HR] 4.3, p<0.0001), BRAF mutation (HR: 5.1, p<0.0001), EREG low expression (HR: 1.6, p = 0.021) and absence of severe/moderate skin rash (HR: 4.0, p<0.0001) as independent prognostic factors for decreased TTP. Similarly, KRAS (HR 2.9, p = 0.01), BRAF mutation (HR: 3.0, p = 0.001), EREG low expression (HR: 1.7, p = 0.021), absecence of severe/moderate skin rash (HR: 3.7, p<0.0001) and the presence of undifferantited tumours (HR: 2.2, p = 0.001) were revealed as independent prognostic factors for decreased OS. Conclusions These results underscore that KRAS-BRAF mutations and EREG expression can be used as biomarkers to further select patients undergoing anti-EGFR treatment.


PLOS ONE | 2008

Tumor BRCA1, RRM1 and RRM2 mRNA expression levels and clinical response to first-line gemcitabine plus docetaxel in non-small-cell lung cancer patients.

Ioannis Boukovinas; Chara Papadaki; Pedro Mendez; Miquel Taron; Dimitris Mavroudis; Anastasios Koutsopoulos; Maria Sanchez-Ronco; Jose Javier Sanchez; Maria Trypaki; Eustathios Staphopoulos; Vassilis Georgoulias; Rafael Rosell; John Souglakos

Background Overexpression of RRM1 and RRM2 has been associated with gemcitabine resistance. BRCA1 overexpression increases sensitivity to paclitaxel and docetaxel. We have retrospectively examined the effect of RRM1, RRM2 and BRCA1 expression on outcome to gemcitabine plus docetaxel in advanced non-small-cell lung cancer (NSCLC) patients. Methodology and Principal Findings Tumor samples were collected from 102 chemotherapy-naïve advanced NSCLC patients treated with gemcitabine plus docetaxel as part of a randomized trial. RRM1, RRM2 and BRCA1 mRNA levels were assessed by quantitative PCR and correlated with response, time to progression and survival. As BRCA1 levels increased, the probability of response increased (Odds Ratio [OR], 1.09: p = 0.01) and the risk of progression decreased (hazard ratio [HR], 0.99; p = 0.36). As RRM1 and RRM2 levels increased, the probability of response decreased (RRM1: OR, 0.97; p = 0.82; RRM2: OR, 0.94; p<0.0001) and the risk of progression increased (RRM1: HR, 1.02; p = 0.001; RRM2: HR, 1.005; p = 0.01). An interaction observed between BRCA1 and RRM1 allowed patients to be classified in three risk groups according to combinations of gene expression levels, with times to progression of 10.13, 4.17 and 2.30 months (p = 0.001). Low BRCA1 expression was the only factor significantly associated with longer time to progression in 31 patients receiving cisplatin-based second-line therapy. Conclusions The mRNA expression of BRCA1, RRM1 and RRM2 is potentially a useful tool for selecting NSCLC patients for individualized chemotherapy and warrants further investigation in prospective studies.

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Kostas Kalbakis

National and Kapodistrian University of Athens

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Lambros Vamvakas

National and Kapodistrian University of Athens

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