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Dive into the research topics where Sefik Igdem is active.

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Featured researches published by Sefik Igdem.


Annals of Oncology | 2011

Treatment results and prognostic factors in primary thyroid lymphoma patients: a Rare Cancer Network study

C. Onal; Y. Li; Robert C. Miller; Philip Poortmans; N. Constantinou; Damien C. Weber; B.M. Atasoy; Sefik Igdem; Mahmut Ozsahin; E. Ozyar

BACKGROUND this study analyzed prognostic factors and treatment outcomes of primary thyroid lymphoma. PATIENTS AND METHODS data were retrospectively collected for 87 patients (53 stage I and 34 stage II) with median age 65 years. Fifty-two patients were treated with single modality (31 with chemotherapy alone and 21 with radiotherapy alone) and 35 with combined modality treatment. Median follow-up was 51 months. RESULTS sixty patients had aggressive lymphoma and 27 had indolent lymphoma. The 5- and 10-year overall survival (OS) rates were 74% and 71%, respectively, and the disease-free survival (DFS) rates were 68% and 64%. Univariate analysis revealed that age, tumor size, stage, lymph node involvement, B symptoms, and treatment modality were prognostic factors for OS, DFS, and local control (LC). Patients with thyroiditis had significantly better LC rates. In multivariate analysis, OS was influenced by age, B symptoms, lymph node involvement, and tumor size, whereas DFS and LC were influenced by B symptoms and tumor size. Compared with single modality treatment, patients treated with combined modality had better 5-year OS, DFS, and LC. CONCLUSIONS combined modality leads to an excellent prognosis for patients with aggressive lymphoma but does not improve OS and LC in patients with indolent lymphoma.


International Journal of Radiation Oncology Biology Physics | 2012

Management of Adenoid Cystic Carcinoma of the Breast: A Rare Cancer Network Study

Kaouthar Khanfir; Adel Kallel; Sylviane Villette; Yazid Belkacemi; Claire Vautravers; T.D. Nguyen; Robert C. Miller; Ye Xiong Li; Alphonse G. Taghian; L Boersma; Philip Poortmans; Hadassah Goldberg; Hansjorg Vees; Elżbieta Senkus; Sefik Igdem; M. Ozsahin; Wendy Jeanneret Sozzi

BACKGROUND Mammary adenoid cystic carcinoma (ACC) is a rare breast cancer. The aim of this retrospective study was to assess prognostic factors and patterns of failure, as well as the role of radiation therapy (RT), in ACC. METHODS Between January 1980 and December 2007, 61 women with breast ACC were treated at participating centers of the Rare Cancer Network. Surgery consisted of lumpectomy in 41 patients and mastectomy in 20 patients. There were 51(84%) stage pN0 and 10 stage cN0 (16%) patients. Postoperative RT was administered to 40 patients (35 after lumpectomy, 5 after mastectomy). RESULTS With a median follow-up of 79 months (range, 6-285), 5-year overall and disease-free survival rates were 94% (95% confidence interval [CI], 88%-100%) and 82% (95% CI, 71%-93%), respectively. The 5-year locoregional control (LRC) rate was 95% (95% CI, 89%-100%). Axillary lymph node dissection or sentinel node biopsy was performed in 84% of cases. All patients had stage pN0 disease. In univariate analysis, survival was not influenced by the type of surgery or the use of postoperative RT. The 5-year LRC rate was 100% in the mastectomy group versus 93% (95% CI, 83%-100%) in the breast-conserving surgery group, respectively (p = 0.16). For the breast-conserving surgery group, the use of RT significantly correlated with LRC (p = 0.03); the 5-year LRC rates were 95% (95% CI, 86%-100%) for the RT group versus 83% (95% CI, 54%-100%) for the group receiving no RT. No local failures occurred in patients with positive margins, all of whom received postoperative RT. CONCLUSION Breast-conserving surgery is the treatment of choice for patients with ACC breast cancer. Axillary lymph node dissection or sentinel node biopsy might not be recommended. Postoperative RT should be proposed in the case of breast-conserving surgery.


Radiotherapy and Oncology | 2010

Information needs of early-stage prostate cancer patients: A comparison of nine countries

Deb Feldman-Stewart; Carlo Capirci; Sarah Brennenstuhl; Christine Tong; Ufuk Abacioglu; Marzena Gawkowska-Suwinska; Francis van Gils; Alicja Heyda; Sefik Igdem; Victor Macias; Isabel Monteiro Grillo; Clare Moynihan; Madelon Pijls-Johannesma; Chris Parker; Nuno Pimentel; Herbert Wördehoff

BACKGROUND AND PURPOSE Providing information to patients can improve their medical and psychological outcomes. We sought to identify core information needs common to most early-stage prostate cancer patients in participating countries. MATERIAL AND METHODS Convenience samples of patients treated 3-24 months earlier were surveyed in Canada, England, Italy, Germany, Poland, Portugal, Netherlands, Spain, and Turkey. Each participant rated the importance of addressing each of 92 questions in the diagnosis-to-treatment decision interval (essential/desired/no opinion/avoid). Multivariate modelling determined the extent of variance accounted by covariates, and produced an unbiased prediction of the proportion of essential responses for each question. RESULTS Six hundred and fifty-nine patients responded (response rates 45-77%). On average, 35-53 questions were essential within each country; similar questions were essential to most patients in most countries. Beyond cross-country similarities, each country showed wide variability in the number and which questions were essential. Multivariate modelling showed an adjusted R-squared with predictors country, age, education, and treatment group of only 6% of the variance. A core of 20 questions were predicted to be essential to >2/3 of patients. CONCLUSIONS Core information can be identified across countries. However, providing the core should only be a first step; each country should then provide information tailored to the needs of the individual patient.


International Journal of Radiation Oncology Biology Physics | 2012

Outcome and prognostic factors in endometrial stromal tumors: a Rare Cancer Network study

Ulrike Schick; Yasmin Bolukbasi; Juliette Thariat; Roxolyana Abdah-Bortnyak; Abraham Kuten; Sefik Igdem; Hale Caglar; Zeynep Özsaran; Kristina Lössl; Ursula Schleicher; Daniel Zwahlen; Sylviane Villette; Hansjörg Vees

PURPOSE To provide further understanding regarding outcome and prognostic factors of endometrial stromal tumors (EST). METHODS AND MATERIALS A retrospective analysis was performed on the records of 59 women diagnosed with EST and treated with curative intent between 1983 and 2007 in the framework of the Rare Cancer Network. RESULTS Endometrial stromal sarcomas (ESS) were found in 44% and undifferentiated ESS (UES) in 49% of the cases. In 7% the grading was unclear. Of the total number of patients, 33 had Stage I, 4 Stage II, 20 Stage III, and 1 presented with Stage IVB disease. Adjuvant chemotherapy was administered to 12 patients, all with UES. External-beam radiotherapy (RT) was administered postoperatively to 48 women. The median follow-up was 41.4 months. The 5-year overall survival (OS) rate was 96.2% and 64.8% for ESS and UES, respectively, with a corresponding 5-year disease-free survival (DFS) rate of 49.4% and 43.4%, respectively. On multivariate analysis, adjuvant RT was an independent prognostic factor for OS (p = 0.007) and DFS (p = 0.013). Locoregional control, DFS, and OS were significantly associated with age (≤60 vs. >60 years), grade (ESS vs. UES), and International Federation of Gynecology and Obstetrics stage (I-II vs. III-IV). Positive lymph node staging had an impact on OS (p < 0.001). CONCLUSION The prognosis of ESS differed from that of UES. Endometrial stromal sarcomas had an excellent 5-year OS, whereas the OS in UES was rather low. However, half of ESS patients had a relapse. For this reason, adjuvant treatment such as RT should be considered even in low-grade tumors. Multicenter randomized studies are still warranted to establish clear guidelines.


Medical Decision Making | 2011

Information for Decision Making by Patients With Early-Stage Prostate Cancer: A Comparison Across 9 Countries

Deb Feldman-Stewart; Carlo Capirci; Sarah Brennenstuhl; Christine Tong; Ufuk Abacioglu; Marzena Gawkowska-Suwinska; Francis van Gils; Alicja Heyda; Sefik Igdem; Victor Macias; Isabel Monteiro Grillo; Clare Moynihan; Madelon Pijls-Johannesma; Chris Parker; Nuno Pimentel; Herbert Wördehoff

Purpose: To describe decisional roles of patients with early-stage prostate cancer in 9 countries and to compare the information they rated important for decision making (DM). Method: A survey of recently treated patients was conducted in Canada, Italy, England, Germany, Poland, Portugal, Netherlands, Spain, and Turkey. Participants indicated their decisional role in their actual decision and the role they would prefer now. Each participant also rated (essential/desired/no opinion/avoid) the importance of obtaining answers, between diagnosis and treatment decision, to each of 92 questions. For each essential/desired question, participants specified all purposes for that information (to help them: understand/decide/plan/not sure/other). Results: A total of 659 patients participated with country-specific response rates between 58%-77%. Between 83%-96% of each country’s participants recalled actually taking an active decisional role and, in most countries, that increased slightly if they were to make the decision today; there were no significant differences among countries. There was a small reliable difference in the mean number of questions rated essential for DM across countries. More striking, however, was the wide variability within each country: no question was rated essential for DM by even 50% of its participants but almost every question was rated essential by some. Conclusions: Almost all participants from each country want to participate in their treatment decisions. Although there are country-specific differences in the amount of information required, wide variation within each country suggests that information that patients feel is essential or desired for DM should be addressed on an individual basis in all countries.


Asian Pacific Journal of Cancer Prevention | 2014

Vitamin D Levels in Patients with Breast Cancer: Importance of Dressing Style

Gül Alço; Sefik Igdem; Maktav Dincer; Vahit Ozmen; Sezer Saglam; Derya Selamoglu; Zeynep Erdogan; Cetin Ordu; Sedef Yenice; Coskun Tecimer; Gokhan Demir; Gülistan Köksal; S. Okkan

BACKGROUND Vitamin D deficiency is a potentially modifiable risk factor that may be targeted for breast cancer (BC) prevention. It may also be related to prognosis after diagnosis and treatment. The aim of our study was to determine the prevalence of vitamin D deficiency as measured by serum 25-hydroxy vitamin D (25-OHD) levels in patients with BC and to evaluate its correlations with life-style and treatments. MATERIALS AND METHODS This study included 186 patients with stage 0-III BC treated in our breast center between 2010-2013. The correlation between serum baseline 25-OHD levels and supplement usage, age, menopausal status, diabetes mellitus, usage of bisphosphonates, body-mass index (BMI), season, dressing style, administration of systemic treatments and radiotherapy were investigated. The distribution of serum 25-OHD levels was categorized as deficient (<10ng/ ml), insufficient (10-24 ng/ml), and sufficient (25-80 ng/ml). RESULTS The median age of the patients was 51 years (range: 27-79 years) and 70% of them had deficient/insufficient 25-OHD levels. On univariate analysis, vitamin D deficiency/insufficiency was more common in patients with none or low dose vitamin D supplementation at the baseline, high BMI (≥25), no bisphosphonate usage, and a conservative dressing style. On multivariate analysis, none or low dose vitamin D supplementation, and decreased sun-exposure due to a conservative dressing style were found as independent factors increasing risk of vitamin D deficiency/insufficiency 28.7 (p=0.002) and 13.4 (p=0.003) fold, respectively. CONCLUSIONS The prevalence of serum 25-OHD deficiency/insufficiency is high in our BC survivors. Vitamin D status should be routinely evaluated for all women, especially those with a conservative dressing style, as part of regular preventive care, and they should take supplemental vitamin D.


Asian Pacific Journal of Cancer Prevention | 2012

Impact of Adjuvant Chemoradiotherapy for Rectal Cancer on the Long-Term Quality of Life and Late Side Effects: A Multicentric Clinical Evaluation by the Turkish Oncology Group

Diclehan Kılıç; D. Yalman; Gorkem Aksu; Beste M. Atasoy; Sefik Igdem; Fazilet Oner Dincbas; Suayib Yalcin

AIM Although preoperative chemoradiatherapy (CRT) has proven its benefits in terms of decreased toxicity, there is still a considerable amount of cases that do not receive postoperative CRT. Oncologists at different geographic locations still need to know the long-term effects of this treatment in order to manage patients successfully. The current paper reports on long-term quality of life (QOL) and late side effects after adjuvant CRT in rectal cancer patients from 5 centers in Anatolia. METHODS Rectal cancer patients treated with postoperative CRT with minimum 1-year follow-up and were in complete remission, were evaluated according to RTOG and LENT-SOMA scales. They were also asked to complete Turkish version of EORTCQLQ-C30 questionnaire and the CR-38 module. Each center participated with the required clinical data. RESULTS Two hundred and thirty patients with median age of 55 years participated and completed the study. Median follow-up time was 5 years. All patients received RT concomitant with chemotherapy. Common parameters that both increased functional health scales and yielded better symptom scores were long term interval after treatment and sphincter-saving surgery. In addition, surgery type and follow-up time were determined to be predictors of QOL scores and late toxicity grade. CONCLUSION Postoperative CRT was found to have a great impact on the long term QOL and side effects in rectal cancer survivors. The factors that adversely affect these are abdominoperineal resection and shorter interval. The findings may encourage life-long follow-up and cooperation with patients, which should be mentioned during the initial counseling.


Oncology Letters | 2015

Clinical and histopathological factors associated with Ki-67 expression in breast cancer patients

Gül Alço; Atilla Bozdogan; Derya Selamoglu; Kezban Nur Pilanci; Sitki Tuzlali; Cetin Ordu; Sefik Igdem; S. Okkan; Maktav Dincer; Gokhan Demir; Vahit Ozmen

The aim of the present study was to identify the optimal Ki-67 cut-off value in breast cancer (BC) patients, and investigate the association of Ki-67 expression levels with other prognostic factors. Firstly, a retrospective search was performed to identify patients with stage I–III BC (n=462). A range of Ki-67 index values were then assigned to five groups (<10, 10–14, 15–19, 20–24 and ≥25%). The correlation between the Ki-67 index and other prognostic factors [age, tumor type, histological and nuclear grade, tumor size, multifocality, an in situ component, lymphovascular invasion (LVI), estrogen and progesterone receptor (ER/PR) expression, human epidermal growth factor receptor (HER-2) status, axillary involvement and tumor stage] were investigated in each group. The median Ki-67 value was revealed to be 20% (range, 1–95%). A young age (≤40 years old), tumor type, size and grade, LVI, ER/PR negativity and HER-2 positivity were revealed to be associated with the Ki-67 level. Furthermore, Ki-67 was demonstrated to be negatively correlated with ER/PR expression (P<0.001), but positively correlated with tumor size (P<0.001). The multivariate analysis revealed that a Ki-67 value of ≥15% was associated with the largest number of poor prognostic factors (P=0.036). In addition, a Ki-67 value of ≥15% was identified to be statistically significant in association with certain luminal subtypes. The rate of disease-free survival was higher in patients with luminal A subtype BC (P=0.036). Following the correlation analysis for the Ki-67 index and the other prognostic factors, a Ki-67 value of ≥15% was revealed to be the optimal cut-off level for BC patients.


Rare Tumors | 2016

Outcome and Predictive Factors in Uterine Carcinosarcoma Using Postoperative Radiotherapy: A Rare Cancer Network Study

Daniel Zwahlen; Ulrike Schick; Yasemin Bolukbasi; Juliette Thariat; Roxolyana Abdah-Bortnyak; Abraham Kuten; Sefik Igdem; Hale Caglar; Zeynep Özsaran; Kristina Loessl; Kaouthar Khanfir Belkaaloul; Sylviane Villette; Hansjörg Vees

Uterine carcinosarcomas (UCS) are rare tumors. Consensus regarding therapeutic management in non-metastatic disease is lacking. This study reports on outcome and predictive factors when using postoperative radiotherapy. We analyzed a retrospective analysis in 124 women treated between 1987-2007 in the framework of the Rare-Cancer-Network. Median follow-up was 27 months. Postoperative pelvic EBRT was administered in 105 women (85%) and 92 patients (74%) received exclusive or additional vaginal brachytherapy. Five-year overall survival (OS), disease-free survival (DFS), cancer specific survival (CSS) and locoregional control (LRC) were 51.6% (95% CI 35-73%), 53.7% (39-71%), 58.6% (38-74%) and 48% (38-67%). Multivariate analysis showed that external beam radiation therapy (EBRT) >50Gy was an independent prognostic factor for better OS (P=0.03), CSS (P=0.02) and LRC (P=0.01). Relative risks (RR) for better OS (P=0.02), DFS (P=0.04) and LRC (P=0.01) were significantly associated with younger age (≤60 years). Higher brachytherapy (BT)-dose (>9Gy) improved DFS (P=0.04) and LRC (P=0.008). We concluded that UCS has high systemic failure rate. Local relapse was reduced by a relative risk factor of over three in all stages of diseases when using higher doses for EBRT and brachytherapy. Postoperative RT was most effective in UCS stage I/II-diseases.


Rare Tumors | 2014

History of the Rare Cancer Network and past research

René O. Mirimanoff; Mahmut Ozsahin; Juliette Thariat; Enis Ozyar; Ulrike Schick; Berrin Pehlivan; Marco Krengli; Alessandra Franzetti Pellanda; Hansjörg Vees; Ling Cai; Luciano Scandolaro; Yazid Belkacemi; Salvador Villà; Sefik Igdem; Myroslav Lutsyk; Robert C. Miller

Approximately, twenty years ago, the Rare Cancer Network (RCN) was formed in Lausanne, Switzerland, to support the study of rare malignancies. The RCN has grown over the years and now includes 130 investigators from twenty-four nations on six continents. The network held its first international symposium in Nice, France, on March 21-22, 2014. The proceedings of that meeting are presented in two companion papers. This manuscript reviews the history of the growth of the RCN and contains the abstracts of fourteen oral presentations made at the meeting of prior RCN studies. From 1993 to 2014, 74 RCN studies have been initiated, of which 54 were completed, 10 are in progress or under analysis, and 9 were stopped due to poor accrual. Forty-four peer reviewed publications have been written on behalf of the RCN.

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S. Okkan

Istanbul Bilim University

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Gül Alço

Istanbul Bilim University

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Salvador Villà

Autonomous University of Barcelona

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Philip Poortmans

Radboud University Nijmegen

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Cetin Ordu

Istanbul Bilim University

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