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Featured researches published by Nikolaos Xenidis.


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.


American Journal of Clinical Oncology | 2013

Transtympanic Injections of N-acetylcysteine for the Prevention of Cisplatin-induced Ototoxicity A Feasible Method With Promising Efficacy

Maria Riga; Leonidas Chelis; Stylianos Kakolyris; Stergios Papadopoulos; Sofia Stathakidou; Eleni Chamalidou; Nikolaos Xenidis; K. Amarantidis; Prokopios Dimopoulos; Vasilios Danielides

Objectives:Ototoxicity is a common and irreversible adverse effect of cisplatin treatment with great impact on the patients’ quality of life. N-acetylcysteine is a low-molecular-weight agent which has shown substantial otoprotective activity. The role of transtympanic infusions of N-acetylcysteine was examined in a cohort of patients treated with cisplatin-based regimens. Patients and Methods:Twenty cisplatin-treated patients were subjected, under local anesthesia, to transtympanic N-acetylcysteine (10%) infusions in 1 ear, during the hydration procedure preceding intravenous effusion of cisplatin. The contralateral ear was used as control. The number of transtympanic infusions was respective to the number of administered cycles. Hearing acuity was evaluated before each cycle with pure tone audiometry by an audiologist blinded to the treated ear. Results:A total of 84 transtympanic infusions were performed. In treated ears, no significant changes in auditory thresholds were recorded. In the control ears cisplatin induced a significant decrease of auditory thresholds at the 8000 Hz frequency band (P=0.008). At the same frequency (8000 Hz), the changes in auditory thresholds were significantly larger for the control ears than the treated ones (P=0.005). An acute pain starting shortly after the injection and lasting for a few minutes seemed to be the only significant adverse effect. Conclusions:Transtympanic injections of N-acetylcysteine seem to be a feasible and effective otoprotective strategy for the prevention of cisplatin-induced ototoxicity. Additional studies are required to further clarify the efficiency of this treatment and determine the optimal dosage and protocol.


BMC Cancer | 2012

Reversible Posterior Leukoencephalopathy Syndrome Induced by Pazopanib

Leonidas Chelis; Vasilios D. Souftas; Kiriakos Amarantidis; Nikolaos Xenidis; Eleni Chamalidou; Prokopios Dimopoulos; Prodromos Michailidis; Evagelos Christakidis; Panagiotis Prassopoulos; Stylianos Kakolyris

BackgroundThe reversible posterior leukoencephalopathy syndrome is a clinical/radiological syndrome characterized by headache, seizures, impaired vision, acute hypertension, and typical magnetic resonance imaging findings. There are several reports in the literature that depict its occurrence in cancer patients. The list of common anticancer and supportive care drugs that predispose to reversible posterior leukoencephalopathy syndrome is expanding and includes not only a large number of chemotherapeutic agents but also an increased number of new targeted drugs, particularly angiogenesis inhibitors such as bevacizumab,sorefenib and sunitinib. Pazopanib is an oral tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor, platelet-derived growth factor receptor, and c-Kit which after a positive phase III randomized clinical trial in patients with advanced renal cell cancer received FDA approval for the treatment of advanced renal cell carcinoma. Until now no cases of reversible posterior leukoencephalopathy syndrome induced by pazopanib have been reported.Case reportWe present the case of a 40 years old female patient with heavily pre-treated metastatic renal cell carcinoma who received pazopanib as salvage treatment. After 21 days of pazopanib therapy the patient referred to the emergency department with epileptic seizure, impaired vision at both eyes and headache. MRI of the brain revealed subcortical oedema at the occipital and parietal lobes bilaterally. She was treated with anticonvulsants, i.v. administration of mannitol and antihypertensives and she recovered completely from her symptoms and was discharged on the tenth hospital day. A brain MRI performed 3 weeks after showed that the subcortical oedema had been subsided.ConclusionIn conclusion this is the first case of pazopanib induced reversible posterior leukoencephalopathy syndrome. Although usually reversible, this syndrome is a serious and potentially life threatening adverse effect, if untreated, that should be considered by physicians treating metastatic renal cell carcinoma patients with pazopanib.


Chemotherapy | 2010

Biweekly Vinorelbine and Gemcitabine as Second-Line Treatment and Beyond in Non-Small Cell Lung Cancer

Leonidas Chelis; Nikolaos Xenidis; K. Amarantidis; P. Prassopoulos; E. Chamalidou; K. Neanidis; D. Mikroulis; Ekaterini Chatzaki; Petros Karakitsos; Stylianos Kakolyris

Background: To evaluate the activity and tolerance of gemcitabine (GEM) in combination with vinorelbine (VRL) in pretreated patients with advanced non-small cell lung cancer (NSCLC). Patients and Methods: Fifteen patients with advanced NSCLC who had disease progression after a cisplatin- or taxane-based front-line regimen were enrolled into a 2-stage design trial and were treated with VRL 30 mg/m2 i.v. for 10 min followed by GEM 1,200 mg/m2 i.v. for 30 min on days 1 and 15 of each 28-day cycle. Chemotherapy was given for 6 cycles unless disease progression or unacceptable toxicity was seen. The patients’ median age was 64 years and the performance status (WHO) was 0 (n = 7), 1 (n = 5), and 2 (n = 3). The treatment was second line for 10 (67%) and third line or more for 5 (33%) patients. Results: No complete or partial responses were observed. Stable disease was seen in 4 (27%) patients and progressive disease in 11 (73%). The median time to tumor progression was 3 months (range 1–12) and the median survival was 4 months (range 2–31). Severe myelotoxicity was infrequent. Grade 2 neutropenia was observed in 2 (13%) patients, grade 2 thrombocytopenia in 1 (7%), and grade 2 anemia in 3 (20%). Nonhematologic toxicities were very mild and easily manageable. Conclusion: The GEM plus VRL combination at the present doses and schedule is a safe but ineffective regimen; therefore, it is not recommended as second-line treatment in patients with advanced NSCLC.


Acta Oncologica | 2010

A dose escalation study of docetaxel plus capecitabine in combination with oxaliplatin in patients with advanced solid tumors.

K. Amarantidis; Nikolaos Xenidis; Leonidas Chelis; Anestis Chiotis; Apostolos Tentes; Ekaterini Chatzaki; Alexandros Kortsaris; Alexandros Polychronidis; Petros Karakitsos; Stylianos Kakolyris

Abstract Objectives. Capecitabine (CAP), Oxaliplatin (OX) and Docetaxel (DOC) have shown considerable activity in a wide range of solid tumors. A phase I study was conducted in order to determine the maximum-tolerated dose (MTD) and dose-limiting toxicities (DLTs) of their combination in patients with advanced solid tumors. Patients and methods. Twenty-one patients were enrolled. The patients median age was 68 years, 15 were male, and 12 were chemo-naïve. DOC was administered on day 1 as an 1-hour (iv) infusion at a standard dose of 50 mg/m2. OX was administered on day 1 as a 2-hour (iv) infusion at escalating doses ranging from 70–80 mg/m2. CAP was administered orally on days 1 to 7 at escalating doses ranging from 2 000–2 750 mg/m2 given as two daily divided doses. Treatment was repeated every two weeks. Results. Six different dose-levels were examined. At dose-level VI, two of three enrolled patients presented DLTs (one patient diarrhea and asthenia grade 3 and another grade 3 diarrhea), and thus, the recommended MTD for future phase II studies is CAP 2 750 mg/m2 , DOC 50 mg/m2 and OX 75 mg/m2. A total of 121 treatment cycles were administered. Grade 3 neutropenia was observed in six (5%) treatment cycles and grade 3 thrombocytopenia in one (1%). There was no febrile episode. Grade 3 asthenia was observed in three (14%) patients, grade 3 diarrhea in four (19%), grade 3 neuropathy in one (5%), and grade 1/2 hand-foot syndrome in three (14%). Other toxicities were uncommon. There was no treatment related death. Four (29%) PRs and seven (50%) SD were observed among 14 evaluable patients. Responses were seen in patients with renal (n = 1), gastric (n = 2) and pancreatic (n = 1) cancer. Conclusions. These results demonstrate that CAP, DOC and OX can be safely combined at clinically relevant doses and this regimen merits further evaluation.


Case Reports in Gastroenterology | 2011

Synchronous Carcinoma of the Ampulla of Vater and Colon Cancer

Anastasios J. Karayiannakis; Stylianos Kakolyris; Georgios Kouklakis; Nikolaos Xenidis; Helen Bolanaki; Christos Tsalikidis; Constantinos Simopoulos

Carcinoma of the papilla of Vater is a relatively rare tumor and its coexistence with other primary sporadic cancers is very exceptional. Here we report the case of a 76-year-old man who presented with painless obstructive jaundice, pathologically elevated liver function tests and increased serum levels of carbohydrate antigen 19-9 and carcinoembryonic antigen. Endoscopic retrograde cholangiography revealed a large polypoid mass in the ampulla of Vater. A large tumor in the ascending colon was also incidentally detected by abdominal computed tomography. Endoscopic biopsies from both lesions showed adenocarcinomas. Metastases to the liver and to the hepatoduodenal ligament and hepatic artery lymph nodes were found during surgery. Right colectomy and a biliary bypass were performed. Histological analysis showed an ampullary adenocarcinoma with metastases to regional lymph nodes and the liver and a colonic adenocarcinoma with local invasion into the pericolic fat. Treatment with gemcitabine plus cisplatin was suggested postoperatively. The association of sporadic ampullary and colonic adenocarcinomas and the mutually increased risk of developing either a synchronous or a metachronous tumor following each other should be considered in patients with primary ampullary or colorectal cancer during the preoperative evaluation and postoperative follow-up of these patients.


Journal of Clinical Oncology | 2014

The importance of sequence in rescheduling bevacizumab and chemotherapy administration in the first-line treatment of metastatic colorectal carcinoma (mCRC).

Leonidas Chelis; Nikolaos Xenidis; Kiriakos Amarantidis; Nikolaos Diamantopoulos; Anastasios L. Boutis; Triantafyllia Koukaki; Prodromos Michailidis; Evagelos Christakidis; Athanasios Chalvatzis; Dimitrios Matthaios; Savas Deftereos; Nikos Courcoutsakis; Panagiotis Prassopoulos; Stylianos Kakolyris

617 Background: One of the proposed mechanisms of action for bevacizumab is by reducing the interstitial fluid pressure (IFP) allowing an increased penetration and uptake of chemotherapy agents in tumors. Clinical and laboratory data suggest that the decrease of IFP occurs after a few days of bevacizumab administration and intratumoral delivery of chemotherapy increase when bevacizumab precedes chemotherapy. We hypothesized that altering the schedule of BEV/FOLFOX regimen would improve the efficacy of the regimen and increase objective response rate. Methods: Patients (pts) with mCRC or locally advanced colorectal cancer, with ECOG PS 0-2 were eligible. The treatment schedule was Bevacizumab 5mg/Kg on day 1, standard FOLFOX-4 regimen on days 8-9 at cycles repeated every 14 days. Prior 5-FU/oxaliplatin adjuvant treatment was allowed. The pts were treated for 6 months or until reaching a plateau of response. Standard RECIST v1.1 response evaluation criteria were used. Primary endpoint of the study was the p...


Journal of Clinical Oncology | 2013

Circulating biomarkers of sorafenib efficacy in advanced HCC.

Leonidas Chelis; Kostantinos Anagnostopoulos; Grigorios Trypsianis; Eleni Kyrillos Hamalidou; Nikolaos Xenidis; Kiriakos Amarantidis; Savas Deftereos; Dimitra Pitsiava; Prodromos Michailidis; Evagelos Christakidis; Dimitrios Michailidis; Dimitrios Matthaios; Filio Koukaki; Alexandros H. Kortsaris; Stylianos Kakolyris

302 Background: Sorafenib represents the only drug with proven efficacy as first-line treatment of hepatocellular carcinoma (HCC). We analyzed 12 cytokines and growth factors related to angiogenesis, inflammation and cell proliferation and evaluated their possible utility as biomarkers of sorafenib efficacy in HCC. Methods: Our study population consisted of 62 HCC patients who received first-line sorafenib and 20 healthy controls. Material was collected at 3 different snapshots: (A) at baseline, (B) after 4 weeks on treatment, (C) at disease progression. Using commercially available ELISA kits we measured the serum levels of: VEGF-A, b FGF, sVEGFR2, Ang2, SDF1, VEGF-C, IL-6, IL-8, AFP, HGF, TSP1, BMP9 (bone morphogenetic protein 9). BMP9, a vascular quiescence factor, was explored for first time in HCC. Results: Patients had significant: (a) higher levels of Ang2, IL-6, IL-8, AFP, HGF, VEGF-A, FGFb , (b) lower levels of SDF1 than controls. At snapshot (B) we found a significant decrease of BMP9 and sVEGFR...


Breast Cancer Research and Treatment | 2009

Detection of occult HER2 mRNA-positive tumor cells in the peripheral blood of patients with operable breast cancer: evaluation of their prognostic relevance

Stella Apostolaki; Maria Perraki; Galatea Kallergi; Maria Kafousi; Savvas Papadopoulos; Athanasios Kotsakis; Athanasios G. Pallis; Nikolaos Xenidis; Lyda Kalmanti; Kostas Kalbakis; Sofia Agelaki; Antonia Kalykaki; Christos Stournaras; Efstathios N. Stathopoulos; Vassilis Georgoulias; Dimitris Mavroudis


Cancer Chemotherapy and Pharmacology | 2011

A multicenter phase I trial of metronomic oral vinorelbine plus cisplatin in patients with NSCLC

Athanasios G. Pallis; Vassilis Chandrinos; Georgia Pavlakou; Nikolaos Xenidis; Ioannis Varthalitis; Nikolaos Vardakis; Lambros Vamvakas; Emmanouel Kontopodis; Maria Rovithi; Vassilis Georgoulias

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Stylianos Kakolyris

Democritus University of Thrace

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Leonidas Chelis

Democritus University of Thrace

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K. Amarantidis

Democritus University of Thrace

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Kostas Kalbakis

National and Kapodistrian University of Athens

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Ekaterini Chatzaki

Democritus University of Thrace

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Petros Karakitsos

National and Kapodistrian University of Athens

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