Cem Simsek

Dr. Cem Simsek

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 March 2019 in Journal of Oncology
Verified
Journal Article
Open access
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CSCem Simsek
Cem Simsek
EEEce Esin
Ece Esin
SYSuayib Yalcin
Suayib Yalcin
Metronomic chemotherapy, continuous and dose-dense administration of chemotherapeutic drugs with lowered doses, is being evaluated for substituting, augmenting, or appending conventional maximum tolerated dose regimens, with preclinical and clinical studies for the past few decades. To date, the principle mechanisms of its action include impeding tumoral angiogenesis and modulation of hosts’ immune system, affecting directly tumor cells, their progenitors, and neighboring stromal cells. Its better toxicity profile, lower cost, and easier use are main advantages over conventional therapies. The evidence of metronomic chemotherapy for personalized medicine is growing, starting with unfit elderly patients and also for palliative treatment. The literature reviewed in this article mainly demonstrates that metronomic chemotherapy is advantageous for selected patients and for certain types of malignancies, which make it a promising therapeutic approach for filling in the gaps. More clinical studies are needed to establish a solidified role for metronomic chemotherapy with other treatment models in modern cancer management.

1 April 2019 in Clinical Cancer Research
Verified
Journal Article
Closed access
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ZWZhixiong Wang
Zhixiong Wang
STSwetha Kambhampati Thiruvengadam
Swetha Kambhampati Thiruvengadam
YCYulan Cheng
Yulan Cheng
KMKe Ma
Ke Ma
CSCem Simsek
Cem Simsek
SMStephen J. Meltzer
Stephen J. Meltzer
Purpose: Barrett9s esophagus is the only known precursor of esophageal adenocarcinoma (EAC). Although endoscopy and biopsy are standard methods for Barrett9s esophagus diagnosis, their high cost and risk limit their use as a screening modality. Here, we sought to develop a Barrett9s esophagus detection method based on methylation status in cytology samples captured by EsophaCap using a streamlined sensitive technique, methylation on beads (MOB). Experimental Design: We conducted a prospective cohort study on 80 patients (52 in the training set; 28 in the test set). We used MOB to extract and bisulfite-convert DNA, followed by quantitative methylation-specific PCR to assess methylation levels of 8 previously selected candidate markers. Lasso regression was applied to establish a prediction model in the training set, which was then tested on the independent test set. Results: In the training set, five of eight candidate methylation biomarkers (p16, HPP1, NELL1, TAC1, and AKAP12) were significantly higher in Barrett9s esophagus patients than in controls. We built a four-biomarker-plus-age lasso regression model for Barrett9s esophagus diagnosis. The AUC was 0.894, with sensitivity 94.4% [95% confidence interval (CI), 71%–99%] and specificity 62.2% (95% CI, 44.6%–77.3%) in the training set. This model also performed with high accuracy for Barrett9s esophagus diagnosis in an independent test set: AUC = 0.929 (P < 0.001; 95% CI, 0.810%–1%), with sensitivity=78.6% (95% CI, 48.8%–94.3%) and specificity = 92.8% (95% CI, 64.1%–99.6%). Conclusions: EsophaCap, in combination with an epigenetic biomarker panel and the MOB method, is a promising, well-tolerated, low-cost esophageal sampling strategy for Barrett9s esophagus diagnosis. This approach merits further prospective studies in larger populations.

15 October 2024 in Gut
Verified
Journal Article
Closed access
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GAGiulio Antonelli
Giulio Antonelli
DLDiogo Libanio
Diogo Libanio
AGAlbert Jeroen De Groof
Albert Jeroen De Groof
Fons van der SommenFons van der Sommen
Fons van der Sommen
PMPietro Mascagni
Pietro Mascagni
MRMario Dinis Ribeiro
Mario Dinis Ribeiro
Artificial intelligence (AI) holds significant potential for enhancing quality of gastrointestinal (GI) endoscopy, but the adoption of AI in clinical practice is hampered by the lack of rigorous standardisation and development methodology ensuring generalisability. The aim of the Quality Assessment of pre-clinical AI studies in Diagnostic Endoscopy (QUAIDE) Explanation and Checklist was to develop recommendations for standardised design and reporting of preclinical AI studies in GI endoscopy. The recommendations were developed based on a formal consensus approach with an international multidisciplinary panel of 32 experts among endoscopists and computer scientists. The Delphi methodology was employed to achieve consensus on statements, with a predetermined threshold of 80% agreement. A maximum three rounds of voting were permitted. Consensus was reached on 18 key recommendations, covering 6 key domains: data acquisition and annotation (6 statements), outcome reporting (3 statements), experimental setup and algorithm architecture (4 statements) and result presentation and interpretation (5 statements). QUAIDE provides recommendations on how to properly design (1. Methods, statements 1–14), present results (2. Results, statements 15–16) and integrate and interpret the obtained results (3. Discussion, statements 17–18). The QUAIDE framework offers practical guidance for authors, readers, editors and reviewers involved in AI preclinical studies in GI endoscopy, aiming at improving design and reporting, thereby promoting research standardisation and accelerating the translation of AI innovations into clinical practice.

6 March 2024 in Journal of Hepatology
Verified
Journal Article
Closed access
CSCem Simsek
Cem Simsek
SWStaffan Wahlin
Staffan Wahlin
CECumali Efe
Cumali Efe

23 January 2020 in Endoscopy
Verified
Journal Article
Closed access
PDF file
LFLea Fayad
Lea Fayad
ATArvind J. Trindade
Arvind J. Trindade
PBPetros C. Benias
Petros C. Benias
CSCem Simsek
Cem Simsek
MRMicheal Raad
Micheal Raad
VKVivek Kumbhari
Vivek Kumbhari
Background Cryoballoon ablation could induce stricture formation to achieve outlet and pouch reduction in patients regaining weight after Roux-en-Y gastric bypass (RYGB). This pilot study aimed to assess technical feasibility and short-term efficacy. Methods A retrospective chart review (January – November 2018) at two academic centers identified patients with weight regain post-RYGB, treated with cryoablation if pouch > 4 cm and/or outlet > 15 mm. Patients were scheduled for surveillance endoscopies at 8 weeks. Results 22 patients presented 10.5 years (SD 4.42) post-RYGB with weight regain of 30.9 kg (SD 13.7). Technical success was 89.5 % for outlet ablation and 93.0 % for pouch ablation. From baseline to 8 weeks, the outlet was reduced from 24.1 mm (95 % confidence interval [CI] 19.8 to 28.5) to 17.1 mm (95 %CI 13.1 to 21.1; P < 0.001), and pouch from 5 cm (95 %CI 4.1 to 5.9) to 3.9 cm (95 %CI 2.6 to 5.1; P < 0.05). Total body weight loss at 8 weeks was 8.1 % (SD 12.8 %). Conclusion Cryoablation appears technically feasible and effective for outlet and/or pouch reduction in the short term.

1 January 2017 in Sage Open Medicine
Verified
Journal Article
Open access
CSCem Simsek
Cem Simsek
SSSebnem Selek
Sebnem Selek
MKMeltem Koca
Meltem Koca
IHIbrahim Celal Haznedaroglu
Ibrahim Celal Haznedaroglu
Ankaferd blood stopper is a standardized mixture of the plants Thymus vulgaris, Glycyrrhiza glabra, Vitis vinifera, Alpinia officinarum, and Urtica dioica and has been used as a topical hemostatic agent and with its clinical application established in randomized controlled trials and case reports. Ankaferd has been successfully used in gastrointestinal endobronchial mucosal and cutaneous bleedings and also in abdominal, thoracic, dental and oropharyngeal, and pelvic surgeries. Ankaferd’s hemostatic action is thought to form a protein complex with coagulation factors that facilitate adhesion of blood components. Besides its hemostatic action, Ankaferd has demonstrated pleiotropic effects, including anti-neoplastic and anti-microbial activities and tissue-healing properties; the underlying mechanisms for these have not been well studied. Ankaferd’s individual components were determined by proteomic and chemical analyses. Ankaferd also augments transcription of some transcription factors which is shown with transcriptomic analysis. The independent effects of these ingredients and augmented transcription factors are not known precisely. Here, we review what is known of Ankaferd blood stopper components from chemical, proteomic, and transcriptomic analyses and propose that individual components can explain some pleiotropic effects of Ankaferd. Certainly more research is needed focusing on individual ingredients of Ankaferd to elucidate their precise and effects.