Yavuz Dizdar
Istanbul University
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Featured researches published by Yavuz Dizdar.
Pediatric Blood & Cancer | 2005
Fulya Yaman Agaoglu; Inci Ayan; Yavuz Dizdar; Rejin Kebudi; Omer Gorgun; Emin Darendeliler
Ependymal tumors are classified as ependymoma (benign or low grade) versus anaplastic ependymoma (malignant or high grade). Ependymomas represent 5–10% of intracranial neoplasm in children. In this study, demographic data and the treatment results of pediatric patients with ependymal tumors, treated in a single institute, is reported.
Pathology & Oncology Research | 2003
Bilge Bilgic; Lora Esberk Ates; Misten Demiryont; Harzem Ozger; Yavuz Dizdar
We report 4 cases of malignant peripheral nerve sheath tumors (MPNST) with neurofibromatosis type 1 (NF1). Mean age was 29.5. Two of them had a family history. Three of them were male. All of them had enlarging mass and pain in the background of neurofibromas. Locations were popliteal, thigh and forearm. The masses were greater than 5 cm in diameter in each case. In two cases the mass was showing continuity with a nerve. One patient had a nonossifying fibroma as well as a MPNST. Wide excision and radiotherapy were applied to three of the patients. One of them did not take any therapy after surgical resection. Two of the patients died of lung metastases after a mean period of 12.5 months. In a majority of NF1 patients MPNST emerges from a preexisting neurofibroma. The patients with NF1 are at greatest risk for developing sarcomas, so they should be followed closely.
Journal of Thoracic Oncology | 2009
Adalet Demir; Mehmet Zeki Gunluoglu; Nergiz Dagoglu; Akif Turna; Yavuz Dizdar; Kamil Kaynak; Sukru Dilege; Nil Molinas Mandel; Dilek Yilmazbayhan; Seyyit Ibrahim Dincer; Atilla Gürses
Introduction: Primitive neuroectodermal tumors (PNETs) are rare, rapidly progressive, small- round cell tumors with a poor prognosis despite multimodal therapy, including surgery and chemoradiotherapy. The treatment of choice was unknown since no clinical series with surgical therapy had been reported. We evaluated the impact of multimodal treatment in patients with PNETs located in the thoracic region. Methods: Between 1998 and 2006, 25 patients with PNETs in the thoracic region were treated in 3 tertiary-care hospitals. The patients consisted of 15 males and 10 females with a mean age of 27.2 years (range, 6-60). The tumor was in the chest wall in 20 (involving the costovertebral junction in 9), the lung in four, and the heart in one patient. Twelve patients received neoadjuvant chemotherapy (54.5%), and 22 of 25 patients underwent surgery. Results: In patients who received neoadjuvant treatment, the mean regression rate was 65.4% (range, 30-100%). Eighteen (82%) patients underwent chest wall resection, while 7 (32%) had vertebral resections, and the remaining 4 (16%) had pulmonary resections. A complete resection was possible in 18 of 22 patients (82%). Patients with incomplete and complete resections had 25% and 56% 5-year survival rates, respectively (p = 0.13). The progression-free 3-year survival rate was 36% and the median survival time was 13 months. The complete resection rate was significantly higher in patients receiving neoadjuvant therapy (p = 0.027). The 5-year survival rate of the patients with or without neoadjuvant therapy was 77% and 37%, respectively (p = 0.22) although it prolonged the disease-free survival (p = 0.01). The 5-year survival rate of patients without costovertebral junction involvement was 66%, whereas patients with PNETs involving the costovertebral junction had a 21% 3-year survival. The difference was statistically significant (p = 0.01). The 5-year progression-free survival rate of patients without costovertebral junction involvement was 58%, whereas patients with PNETs involving the costovertebral junction had a 14% 1-year progression-free survival (p = 0.004). Conclusions: PNET is an aggressive malignancy that often requires multimodal therapy. Induction chemotherapy leads to a greater complete resection rate and better disease-free survival, while involvement of the costovertebral junction indicates a poorer survival.
Acta Chirurgica Belgica | 2012
M. Fayda; Rejin Kebudi; Yavuz Dizdar; Omer Gorgun; Feryal Gün; Gorkem Aksu; Inci Ayan
Abstract Spontaneous pneumothorax is a rare manifestation of primary lung cancer or metastasis. It is estimated that < 1% of all cases of spontaneous pneumothorax are tumor-associated and metastatic osteogenic or soft-tissue sarcomas are associated most commonly with pneumothorax especially in the setting of cytotoxic chemotherapy or radiotherapy. In this article, we report three pediatric cases with osteosarcoma that developed spontaneous pneumothorax during chemotherapy with a review of the literature. Two of them had lung metastasis at the time of the detection of pneumothorax and the remaining patient was found to have a bronchopleural fistula. SPx is an emergency situation and early diagnosis and management can improve prognosis and quality of life of the patient however the optimal management has yet to be determined.
Tumor Biology | 2014
Elif Bilgin Doğru; Yavuz Dizdar; Ece Aksit; Feyyaz Ural; Öner Şanlı; Vildan Yasasever
Extracellular metalloproteinase inducer (EMMPRIN) and a disintegrin and metalloproteinase (ADAM12) play a major role in cancer invasion and metastasis owing to the fact that they are directly related to the cell microenvironment and extracellular matrix (ECM) degradation. The aim of this study was to search for an answer to the question “whether the determination of EMMPRIN and ADAM12 values especially in urine may be helpful for the early diagnosis of prostate cancer without employing invasive methods” and also to check whether they may be useful for the determination of the patients with high metastasis risk. Peripheral blood and urine from 66 prostate cancer patients (40 local, 20 locally advanced, 6 metastatic) and 14 healthy controls were evaluated by enzyme-linked immunosorbent assay (ELISA) method. Serum EMMPRIN and ADAM12 values of the patients were seen to be statistically higher than the serum EMMPRIN and ADAM12 values of the healthy controls (p = 0.01 and p = 0.001, respectively). The urine ADAM12 levels were significantly higher in patients (p = 0.013). No significant relationships were found between urine EMMPRIN values of the patients and the healthy controls (p > 0.05). Positive correlation between urine EMMPRIN–urine ADAM12 tests was found in total patients group (r = 0.683, p = 0.001). Our preliminary results revealed that serum EMMPRIN and ADAM12 values and urine ADAM12 values may be useful markers in prostate cancer therapy. Due to the high correlation between these two tests, we are of the opinion that the use of urine ADAM12 in clinic may be sufficient and favorable together with prostate-specific antigen (PSA) for treatment.
International Urology and Nephrology | 2008
Isin Kilicaslan; Ebru Karayigit; Fikret Bulut; Mert Basaran; Yavuz Dizdar; I. Aslay; Veli Uysal
Ewing’s sarcoma/primitive neuroectodermal tumor (ES/PNET) of the penis has been very rarely defined. We report a case of a 19-year-old patient with a tumor, localized in the dorsal side of penis, composed of small round cells with diffuse membranous mic-2 (CD99) immunopositivity. The patient was treated with multiagent chemotherapy and radiotherapy.
Value in health regional issues | 2016
Makbule Tambas; Fulya Yaman Agaoglu; Ayca Iribas; Murat Guveli; Yavuz Dizdar; Murat Okutan; Dilek Sahin; Nuri Tenekeci; Emin Darendeliler
OBJECTIVES To compare conventionally fractionationed volumetric arc therapy (VMAT) and hypofractionated stereotactic body radiotherapy (SBRT) modalities in terms of prostate-specific antigen (PSA) kinetics, toxicity, and quality of life (QOL) in patients with localized prostate cancer. METHODS Patients received radical radiotherapy as either 33.5 Gy/5 fr for SBRT or 75.6 Gy/35 fr for VMAT. International Prostate Symptom Score (IPSS) and European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Prostate Cancer Module (QLQ-PR25) forms were used to assess QOL. RESULTS Of the 48 patients (28 in SBRT and 20 in VMAT) included in the study, 40 (20 in SBRT and 20 in VMAT) were evaluated for QOL status. PSA control rate was 100% and PSA nadir value was 0.5 ng/dl in both arms during the median follow-up period of 23 months. The magnitude of PSA bounce was higher in the SBRT arm than in the VMAT arm (P = 0.01). The PSA decline rate in the VMAT arm was higher than in the SBRT arm (P = 0.028). Three (10.7%) patients treated with SBRT who had a history of transurethral resection of the prostate (TURP) experienced grade 3 urinary toxicity. No significant difference was observed concerning sexual activity and sexual functioning scores, whereas scores at 10.5 and 13.5 months were decreased in both arms. The SBRT and VMAT arms had similar urinary incontinence, bowel symptoms, and IPSS obstruction scores. The magnitude of increase in IPSS scores at treatment completion was higher in the VMAT arm than in the SBRT arm (P = 0.046). The decrease in hormonal symptom scores at 4.5, 10.5, and 13.5 months was higher in the VMAT arm than in the SBRT arm (P = 0.007, 0.027, and 0.021, respectively). CONCLUSIONS Both treatment modalities had similar effectiveness and provided acceptable outcomes in terms of toxicity and QOL. Grade 3 urinary toxicities might be eliminated with careful patient selection for SBRT.
Asian Pacific Journal of Cancer Prevention | 2013
Elif Bilgin; Yavuz Dizdar; Murat Serilmez; Hilal Oguz Soydinc; Derya Duranyildiz; Vildan Yasasever
BACKGROUND The aim of the present study was to evaluate the serum neuron-specific enolase (NSE) levels in patients with prostate cancer, Hodgkin lymphoma, lung cancer and peripheral nerve tumors. MATERIALS AND METHODS NSE levels were determined by ELISA in the sera of 100 prostate cancer, 47 Hodgkin lymphoma, 35 lung cancer and 35 peripheral nerve tumor patients and also in 132 healthy controls. RESULTS The median levels of serum NSE were elevated in patients with lung cancer (p=0.018) and peripheral nerve tumors (p=0.008). NSE levels in prostate cancer and Hodgkin lymphoma patients were higher than the controls but there was no statistically significant difference (p>0.05). CONCLUSIONS We conclude that NSE may be applied in routine to gain insight about the clinical statuses of various cancer patients, but more studies are needed to determine the organ specificity.
Australian & New Zealand Journal of Obstetrics & Gynaecology | 2004
Aziz Yazar; Mert Basaran; Fulya Yaman; Yavuz Dizdar; Sitki Tuzlali; Sevil Bavbek; Haluk Onat
Non-Hodgkin’s lymphoma (NHL) can involve extranodal sites, the most common being the gastrointestinal tract and the skin. However, uterine involvement by NHL is uncommon. Approximately 40% of cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP)-treated patients are cured. Most of the patients have refractory disease or relapse. Most of the relapses are nodal alone or nodal and extranodal together. In addition, there are relapses limited to extranodal locations. However, although there have been primary uterine NHL reported in published documents, there has been no report found regarding the relapse of malignant NHL confined to the uterus. We present a case of NHL relapse solely in the corpus uteri.
Tumor Biology | 2011
Fulya Yaman Agaoglu; Müge Kovancilar; Yavuz Dizdar; Emin Darendeliler; Stefan Holdenrieder; Nejat Dalay; Ugur Gezer