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Featured researches published by Zafer Kocak.


Cancer | 2007

Extrapulmonary Small-Cell Carcinoma Compared With Small-Cell Lung Carcinoma A Retrospective Single-Center Study

Irfan Cicin; Hakan Karagol; Sernaz Uzunoglu; Kazim Uygun; Ufuk Usta; Zafer Kocak; Murat Caloglu; Mert Saynak; Fusun Tokatli; Cem Uzal

The study was conducted with the aim of reviewing the clinical features, therapy, and natural course of patients with extrapulmonary small‐cell carcinoma (EPSCC) and small‐cell lung carcinoma (SCLC) to better define current concepts regarding EPSCCs.


American Journal of Clinical Oncology | 2003

Granulosa cell tumor of the ovary: retrospective analysis of 45 cases.

Kazim Uygun; Adnan Aydiner; Pinar Saip; Mert Basaran; Faruk Tas; Zafer Kocak; Maktav Dincer; Erkan Topuz

Adult granulosa cell tumors of the ovary are rare neoplasms, accounting for less than 5% of all ovarian malignancies. In addition to the tumor stage, residual disease, patient age, tumor size, extent of surgery, and also some histologic factors have been reported to be of prognostic importance. Tumor registries were screened for all patients treated between 1979 and 1998 for ovarian tumors at the University of Istanbul. There were 952 ovarian carcinomas, of which 47 were granulosa cell tumors. All charts were reviewed, and the clinical data were extracted. Prognostic factors and treatment results were evaluated retrospectively. The median follow-up was 84 (range: 6–141 months) months. According to univariate analysis, there were only two significant factors for overall survival (OS): stage and presence of residual disease. The OS of the 23 patients with early stage (mean, 122 months; median, unreached) was significantly (p = 0.0001) better than the OS of the 22 patients with advanced stage (mean, 34 months; median, 21 months). A significant difference (p = 0.0004) in OS was also observed between patients with residual (mean, 42 months; median, 21 months) and nonresidual (mean, 108 months; median, unreached) disease. In a multivariate analysis, only stage remained statistically significant (p = 0.0001). The overall 5-year survival rate was 55% and median survival after recurrence was 21 months. Despite the small number of patients, the study showed that stage and macroscopic residual disease are significant prognostic factors. The benefit of chemotherapy and radiotherapy remains controversial.


Radiation Oncology | 2011

Postmastectomy irradiation in breast in breast cancer patients with T1-2 and 1-3 positive axillary lymph nodes: Is there a role for radiation therapy?

Rusen Cosar; Cem Uzal; Fusun Tokatli; Bengu Denizli; Mert Saynak; Nesrin Turan; Sernaz Uzunoglu; Alaattin Özen; Atakan Sezer; Kamuran Ibis; Burcu Üregen; Vuslat Yurut-Caloglu; Zafer Kocak

BackgroundWe aimed to evaluate retrospectively the correlation of loco-regional relapse (LRR) rate, distant metastasis (DM) rate, disease free survival (DFS) and overall survival (OS) in a group of breast cancer (BC) patients who are at intermediate risk for LRR (T1-2 tumor and 1-3 positive axillary nodes) treated with or without postmastectomy radiotherapy (PMRT) following modified radical mastectomy (MRM).MethodsNinety patients, with T1-T2 tumor, and 1-3 positive nodes who had undergone MRM received adjuvant systemic therapy with (n = 66) or without (n = 24) PMRT. Patient-related characteristics (age, menopausal status, pathological stage/tumor size, tumor location, histology, estrogen/progesterone receptor status, histological grade, nuclear grade, extracapsular extension, lymphatic, vascular and perineural invasion and ratio of involved nodes/dissected nodes) and treatment-related factors (PMRT, chemotherapy and hormonal therapy) were evaluated in terms of LRR and DM rate. The 5-year Kaplan-Meier DFS and OS rates were analysed.ResultsDifferences between RT and no-RT groups were statistically significant for all comparisons in favor of RT group except OS: LRR rate (3%vs 17%, p = 0.038), DM rate (12% vs 42%, p = 0.004), 5 year DFS (82.4% vs 52.4%, p = 0.034), 5 year OS (90,2% vs 61,9%, p = 0.087). In multivariate analysis DM and lymphatic invasion were independent poor prognostic factors for OS.ConclusionPMRT for T1-2, N1-3 positive BC patients has to be reconsidered according to the prognostic factors and the decision has to be made individually with the consideration of long-term morbidity and with the patient approval.


Medical Oncology | 2010

Recurrent solitary fibrous tumor of the pleura: significant response to radiotherapy

Mert Saynak; Gulden Bayir-Angin; Zafer Kocak; Fulya Oz-Puyan; Murat Hayar; Rusen Cosar-Alas; Altemur Karamustafaoglu; Vuslat Yurut-Caloglu; Murat Caloglu; Yener Yoruk

Solitary fibrous tumor (SFT) of the pleura is an uncommon neoplasm with non-specific symptoms and non-pathognomonical radiological findings. Surgery allows establishment of a definitive diagnosis as well as a cure of the disease. The role of radiotherapy or chemotherapy in the management of the disease is unclear because of the rarity of the disease and the successful results of the surgical treatment. Long-term clinical follow-up may be useful for the patients with SFT because of the potential adverse biological behavior of this tumor, which may lead to repeated recurrences and/or malignant transformation. We reported a 66-year-old woman with recurrence of SFT in the right lung, which had significant response to external thoracic radiotherapy.


Yonsei Medical Journal | 2006

Colonic Metastasis from Carcinoma of the Breast that Mimicks a Primary Intestinal Cancer

Kazim Uygun; Zafer Kocak; Semsi Altaner; Irfan Cicin; Fusun Tokatli; Cem Uzal

Although the lung, liver, or bones are the most common location for distant metastases in breast cancer patients, metastases to the intestinal tract are very rarely recognized in the clinic. We will present an unusual case of colonic metastasis from a carcinoma of the breast that mimics a primary intestinal cancer, along with a through review of English language medical literature. Despite the fact that isolated gastrointestinal (GI) metastases are very rare and much less common than benign disease processes or second primaries of the intestinal tract in patients with a history of breast cancer, metastatic disease should be given consideration whenever a patient experiences GI symptoms.


Strahlentherapie Und Onkologie | 2008

Amifostine use in radiation-induced kidney damage. Preclinical evaluation with scintigraphic and histopathologic parameters.

Mine Kaldir; Rusen Cosar-Alas; Tevfik Fikret Cermik; Yurut-Caloglu; Mert Saynak; Semsi Altaner; Murat Caloglu; Zafer Kocak; Fusun Tokatli; Mevlut Ture; Sule Parlar; Cem Uzal

Purpose:To assess the degree of protective effects of amifostine on kidney functions via semiquantitative static renal scintigraphy and histopathologic analysis.Material and Methods:30 female albino rats were divided into three equal groups as control (CL), radiotherapy alone (RT), and radiotherapy + amifostine (RT+AMI). The animals in the CL and RT groups were given phosphate-buffered saline, whereas the animals in the RT+AMI group received amifostine (200 mg/kg) by intraperitoneal injection 30 min before irradiation. RT and RT+AMI groups were irradiated with a single dose of 6 Gy using a 60Co unit at a source-skin distance of 80 cm to the whole right kidney. They were followed up for 6 months. CL, RT, and RT+AMI groups underwent static kidney scintigraphy at the beginning of the experiment and, again, on the day before sacrificing. Histopathologically, tubular atrophy and fibrosis of the kidney damage were evaluated.Results:After irradiation, the median value of right kidney function was 48% (44–49%) and 50.5% (49%–52%) in RT and RT+AMI groups, respectively (p = 0.0002). Grade 1 kidney fibrosis was observed to be 60% in the RT group, while it was only 30% in the RT+AMI group. Grade 2 kidney fibrosis was 30% and 0% in the RT and RT+AMI group, respectively. Grade 1 tubular atrophy was 70% and 50% in the RT and RT+AMI group, respectively. Grade 2 tubular atrophy effect was the same in both groups (10%).Conclusion:Static kidney scintigraphy represents an objective and reproducible method to noninvasively investigate kidney function following irradiation. Amifostine produced a significant reduction in radiation-induced loss of renal function.Ziel:Beurteilung der protektiven Wirkung von Amifostin auf die Nierenfunktion mittels semiquantitativer statischer szintigraphischer und histopathologischer Analyse.Material und Methodik:30 weibliche Albinoratten wurden in drei Gruppen mit jeweils zehn Tieren aufgeteilt: Kontrolle (CL), alleinige Radiotherapie (RT) und Radiotherapie + Amifostin (RT+AMI). Die Ratten in der CL- und RT-Gruppe erhielten eine Plazebosalzlösung, die Ratten in der RT+AMI-Gruppe 200 mg/kg Amifostin intraperitoneal 30 min vor der Bestrahlung. Die rechten Nieren in der RT- und RT+AMI-Gruppe wurden mit 6 Gy Einzeldosis mit einem 60Co-Gerät bestrahlt. Die Nachbeobachtungszeit betrug 6 Monate. Eine Nierenszintigraphie wurde direkt vor der Bestrahlung und vor Sektion bei den Tieren der RT- und RT+AMI-Gruppe durchgeführt. Der Nierenschaden wurde in der histopathologischen Untersuchung mit Tubulusatrophie und Fibrose qualitativ beurteilt.Ergebnisse:Die mediane Nierenfunktion der rechten Niere betrug in der RT- und RT+AMI-Gruppe 48% (44–49%) und 50,5% (49–52%; p = 0,0002). Grad-1-Fibrose lag in der RT-Gruppe bei 60% und in der RT+AMI-Gruppe bei 30%. Grad-2-Fibrose betrug in der RT-Gruppe 30% und in der RT+AMI-Gruppe 0%. Tubulusatrophie Grad 2 war in beiden Gruppen vergleichbar (10%).Schlussfolgerung:Die statische Nierenszintigraphie ist eine objektive, wiederholbare und nichtinvasive Methode zur Beurteilung der Nierenfunktion nach Bestrahlung. Im Tiermodell konnte Amifostin die strahleninduzierten Nierenschäden verringern.


Toxicology and Industrial Health | 2012

Antiapoptotic and proliferative activity of curcumin on ovarian follicles in mice exposed to whole body ionizing radiation.

Cevat Aktas; Mehmet Kanter; Zafer Kocak

The aim of this study was to evaluate the antiapoptotic and proliferative activity of curcumin (Cur) on the ovarian follicles in mice exposed to whole body ionizing radiation (Rd). The mice were exposed to 8.3 gray whole body Rd, and Cur groups were given as a daily dose of 100 mg/kg of Cur for 10 days (10 days before Rd). The ovaries were collected 3 and 12 h after irradiation. To date, no such studies have been performed on antiapoptotic and proliferative activity of Cur on the ovarian follicles in mice exposed to whole body Rd. Analysis of mice ovary after exposure to Rd by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labeling showed that there were apoptotic cells both in the follicular wall and the antrum, and that the number of follicles showing early atresic features was high 3 h after Rd. On the other hand, analysis of mice ovary 12 h after exposure to Rd showed that the number of follicles containing apoptotic cells with advanced atresic features was significantly higher when compared to the 3-h Rd exposure group. The proliferating cell nuclear antigen -positive granulosa cells were decreased in association with follicular atresia. The groups given treatment were observed to have some benefit from Cur against the damage caused by Rd. The results of this study demonstrate that Cur prevents follicular atresia in Rd-induced apoptosis in ovarian follicles.


Journal of Cancer Research and Therapeutics | 2011

The effect of a flavonoid fractions diosmin + hesperidin on radiation-induced acute proctitis in a rat model

Atakan Sezer; Ufuk Usta; Zafer Kocak; Mehmet Ali Yagci

BACKGROUND To explore the protective effect of a flavonoid fractions diosmin + hesperidin (Daflon), against radiation-induced acute proctitis in an experimental rat model. MATERIALS AND METHODS Thirty four rats were divided into four groups. The rats in Group 1 received Daflon and underwent irradiation. The rats in Group 2 received no Daflon and underwent irradiation. The rats in Group 3 received Daflon and underwent sham irradiation. The rats in Group 4 received no Daflon and underwent sham irradiation. Daflon emulsion (100 mg/kg/day) was administered via an orogastric feeding tube to the rats in groups 1 and 3 starting from 1 day prior to irradiation until the euthanasia day (day 15 following irradiation). Radiation therapy was delivered on a cobalt-60 unit using a single fraction of 17.5 Gy defined at a depth of 1 cm through an anterior portal. Slides were examined by the same pathologist under a light microscope two times in a blinded manner. RESULTS When compared to group 2, the rats of Group 1 showed less glandular distortion and less mucosal inflammation with less infiltration of the crypt epithelia by the inflammatory cells (P < 0.001). A statistically significant increase in all parameters but muscular wall thickness was observed for the rats in Group 2 as compared to the group 3 and 4. CONCLUSIONS Administration of a dose of 100 mg/kg/day of the diosmin + hesperidin resulted in decreased morphologic inflammatory changes. This drug may have protective effects against radiation-induced acute proctitis.


Onkologie | 2006

Isolated Bone Metastasis in Testicular Germ Cell Tumors: A Case Report and Review of the Literature

Kazim Uygun; Hakan Karagol; Zafer Kocak; Irfan Cicin; Omer Yalcin; Murat Caloglu; Osman Simsek; Ferda Akbay Harmandar

Background: In testicular germ cell tumors (GCT), bone metastases are usually seen late in the disease progress and are almost always associated with involvement of other sites. However, isolated bone metastasis is an extremely rare finding in these patients. Case Report: A 43- year-old man was admitted to the neurosurgery department of our hospital suffering from dysarthria, ataxia, headaches and a progressive swelling above the parietooccipital region of the skull. Radiological, biochemical and pathologic tests showed that the lesion of the skull was an isolated skull metastasis as an initial manifestation of nonseminomatous GCT of the testis. Discussion: When a young patient presents with bone pain or painless swelling, even if it is an unusual site and isolated, testicular GCT should be considered as a differential diagnosis, as these lesions could be the first evidence of metastatic GCT.


Clinical Neurology and Neurosurgery | 2003

Isolated bilateral sixth nerve palsy secondary to metastatic carcinoma: a case report with a review of the literature

Zafer Kocak; Yahya Çelik; M. Cem Uzal; Kazim Uygun; Meryem Kaya; Sait Albayram

Isolated sixth nerve palsies usually occur in the vasculopathic age group and are often associated with diabetes mellitus, hypertension, and atherosclerosis but also occur in the presence of skull base tumors. However, isolated bilateral sixth nerve palsies are an extremely rare complication of skull base lesions due to metastatic neoplasms. A case of a 46-year-old man with metastatic small-cell carcinoma of the lung that developed acute bilateral abducens nerve palsies is presented. Although this appears to be an isolated case, metastasis to the skull base must be included in the differential diagnosis of isolated bilateral sixth nerve palsies.

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