Serdar Karakaya

Dr. Serdar Karakaya

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

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

Representative Publications

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17 January 2019 in TURKISH JOURNAL OF MEDICAL SCIENCES
Verified
Journal Article
Open access
SKSerdar Karakaya
Serdar Karakaya
MAMustafa Altay
Mustafa Altay
FEFatma Kaplan Efe
Fatma Kaplan Efe
IKibrahim karadağ
ibrahim karadağ
OÜoktay ünsal
oktay ünsal
DEDerun Taner Ertuğrul
Derun Taner Ertuğrul
Background and aim: In this study, we aimed to investigate the neutrophil/lymphocyte (N/L) ratio, variations in leukocytes and leukocyte subtypes, and the relationship between N/L ratio and insulin resistance (IR) in obesity. Materials and Methods: Ninety six patients and 40 healthy controls were included in this study. Patients’ blood glucose levels, insulin levels, and hemogram parameters upon 8 hours of fasting were determined. Body mass index (BMI) and homeostasis model assessment insulin resistance (HOMA-IR) values were calculated. Results: Neutrophil numbers were found to be higher among IR obese patients than among non-IR obese patients. The N/L ratio was, moreover, found to be higher among IR obese patients, when compared to non IR obese. A positive correlation was found between insulin resistance and both neutrophil and WBC counts. Another positive correlation was also found between insulin levels and the N/L ratio, WBC, and neutrophil counts. Discussion: In our study, leukocyte numbers and subtypes were determined to be higher among obese individuals than among healthy individuals. The N/L ratio had increased significantly only among obese patients who have insulin resistance. Further studies are needed in order to better demonstrate the relationship between the N/L ratio and insulin resistance/inflammation. Key Words: Neutrophil-Lymphocyte Ratio, Obesity, Insulin Resistance

13 March 2017 in Endocrine Research
Verified
Journal Article
Closed access
OBOktay Bulur
Oktay Bulur
KDKursat Dal
Kursat Dal
DEDerun Taner Ertugrul
Derun Taner Ertugrul
MEMurat Eser
Murat Eser
FEFatma Kaplan Efe
Fatma Kaplan Efe
EBEsin Beyan
Esin Beyan
Background: It has been known that thyroid hormones may affect renal function. In this study, we aimed to investigate the effect of levothyroxine replacement on renal function in hypothyroid patients before and after treatment. Methods: We retrospectively investigated free T3 (fT3), free T4 (fT4), TSH, creatinine, and eGFR measurements during both hypothyroid and euthyroid states of hypothyroid patients. The eGFR was calculated using the simplified Modification of Diet in Renal Disease formula. Results: fT3, fT4, and eGFR measurements increased, meanwhile creatinine and TSH levels decreased significantly after euthyroidism was achieved with levothyroxine treatment (p < 0.0001 for all). The correlation analyses revealed that ∆creatinine and ∆TSH levels were significantly correlated before and after levothyroxine treatment (r: 0.288, p < 0.0001). ∆eGFR and ∆TSH levels were significantly correlated before and after LT4 treatment (r: −0.272, p < 0.0001). Conclusion: In this study, we evaluated creatinine and eGFR levels in patients with hypothyroidism and found out that renal function improved in most patients after euthyroidism was achieved. In some patients, above-normal creatinine levels completely returned to normal once the patients became euthyroid.

8 March 2022 in Cureus
Verified
Journal Article
Open access
SKSerdar Karakaya
Serdar Karakaya
IKibrahim karadağ
ibrahim karadağ
MYMehmet Emin Yılmaz
Mehmet Emin Yılmaz
BOBerna Oksuzoglu
Berna Oksuzoglu
Objective: To investigate the effect of hemogram parameters on predicting pathological complete response (pCR) in locally advanced rectal cancer. Methodology: A total of 227 patients with rectal cancer treated with neoadjuvant concurrent chemoradiotherapy (CRT) were retrospectively analyzed. All patients were divided into two subgroups as high or low hemogram parameters according to the cut-off value obtained using the receiver operating characteristic (ROC) curve. Results: In patients with low neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) levels, pCR rate was statistically significantly higher than the group with high NLR and PLR levels (for NLR: 39.77% vs. 5.34%; p<0.001, for PLR: 32.38% vs 7.01%; p<0.001 respectively). In addition, the pCR rate was significantly better in patients with high lymphocyte levels compared to the group with low lymphocyte levels (33.33% vs. 7.5%; p<0.001, respectively). According to the multivariate logistic regression analysis result, NLR and PLR levels were considered as independent predictors to predict pathological complete response [p<0.001, HR: 0.128 (95% CI=0.051 - 0.322) for NLR; p=0.017, HR: 0.332 (95% CI=0.134 - 0.821) for PLR, respectively]. Conclusion: Our study showed that high NLR, PLR, and low lymphocyte levels were correlated with worse pCR rates. In addition to that, NLR and PLR emerged as independent predictive markers.

16 December 2022 in Medicine
Verified
Journal Article
Open access
MGMustafa Gürbüz
Mustafa Gürbüz
SKSaadettin Kiliçkap
Saadettin Kiliçkap
ABAhmet Bilici
Ahmet Bilici
NKNuri Karadurmuş
Nuri Karadurmuş
ASAhmet Sezer
Ahmet Sezer
ADAhmet Demirkazık
Ahmet Demirkazık
Crizotinib is a multikinase inhibitor, effective in non-small cell lung cancer (NSCLC) harboring mesenchymal-epidermal transition (MET) alterations. Although small prospective studies showed efficacy and safety of crizotinib in NSCLC with MET alterations, there is limited real-life data. Aim of this study is to investigate real-life efficacy and safety of crizotinib in patients with advanced NSCLC harboring MET alterations. This was a retrospective, multicenter (17 centers) study of Turkish Oncology Group. Patients’ demographic, histological data, treatment, response rates, survival outcomes, and toxicity data were collected. Outcomes were presented for the study population and compared between MET alteration types. Total of 62 patients were included with a median age of 58.5 (range, 26–78). Major histological type was adenocarcinoma, and 3 patients (4.8%) had sarcomatoid component. The most common MET analyzing method was next generation sequencing (90.3%). MET amplification and mutation frequencies were 53.2% (n = 33) and 46.8% (n = 29), respectively. Overall response rate and disease control rate were 56.5% and 74.2% in whole study population, respectively. Median progression free survival (PFS) was 7.2 months (95% confidence interval [CI]: 3.8–10.5), and median overall survival (OS) was 18.7 months (95% CI: 13.7–23.7), regardless of treatment line. Median PFS was 6.1 months (95% CI: 5.6–6.4) for patients with MET amplification, whereas 14.3 months (95% CI: 6.7–21.7) for patients with MET mutation (P = .217). Median PFS was significantly longer in patients who have never smoked (P = .040), have good performance score (P < .001), and responded to the treatment (P < .001). OS was significantly longer in patients with MET mutation (25.6 months, 95% CI: 15.9–35.3) compared to the patients with MET amplification (11.0 months; 95% CI: 5.2–16.8) (P = .049). In never-smokers, median OS was longer than smoker patients (25.6 months [95% CI: 11.8–39.3] vs 16.5 months [95% CI: 9.3–23.6]; P = .049). The most common adverse effects were fatigue (50%), peripheral edema (21%), nausea (29%) and diarrhea (19.4%). Grade 3 or 4 adverse effects were observed in 6.5% of the patients. This real-life data confirms efficacy and safety of crizotinib in the treatment of advanced NSCLC harboring MET alteration.

2 November 2021 in Future Oncology
Verified
Journal Article
Closed access
EYEmre Yekedüz
Emre Yekedüz
IEİsMail Ertürk
İsMail Ertürk
DTDeniz Tural
Deniz Tural
NKNuri Karadurmuş
Nuri Karadurmuş
SKSerdar Karakaya
Serdar Karakaya
YÜYüksel Ürün
Yüksel Ürün
Aim: The authors present real-world data on the efficacy and safety of nivolumab in patients with metastatic renal cell carcinoma (mRCC). Methods: The Turkish Oncology Group Kidney Cancer Consortiu... Lay abstract Nivolumab is an immune checkpoint inhibitor (ICI) that blocks the communication between T cells and cancer cells and instead activates T cells to fight against cancer. Metastatic renal...

31 March 2025 in Medicina
Verified
Journal Article
Open access
PDF file
ZKZiya KALKAN
Ziya KALKAN
SESenar Ebinc
Senar Ebinc
MAMurat Arcagok
Murat Arcagok
ABAhmet Bilici
Ahmet Bilici
OYOzcan Yildiz
Ozcan Yildiz
MKMuhammet Ali Kaplan
Muhammet Ali Kaplan
Background and Objectives: This study aimed to evaluate the effectiveness of immunotherapy compared to chemotherapy across different treatment lines in patients with pleural mesothelioma. It also sought to identify factors influencing the success of immunotherapy, such as histological subtype, PD-L1 expression, type of asbestos exposure, and metastatic status. Materials and Methods: A retrospective analysis was conducted with 60 patients diagnosed with pleural mesothelioma. Data on age, gender, histological subtype, and asbestos exposure were collected for all patients and PD-L1 expression was assessed in a subset of patients. Patients received either chemotherapy or immunotherapy as first-, second-, and third-line treatments, and progression-free survival (PFS) and treatment responses were evaluated. Results: Among the 60 patients, 35 (58.3%) were male and the median age was 59 years. The majority (71.7%) had epithelioid histology and 28.3% had distant metastases. Asbestos exposure was documented in 65% of the cases. PD-L1 expression of ≥1% was found in 13 of 17 patients tested. First-line treatments included immunotherapy for 11 patients and chemotherapy for the others, with immunotherapy achieving median PFS of 9 months versus 6 months for chemotherapy, although the difference was not statistically significant. In third-line treatments, immunotherapy significantly outperformed chemotherapy with median PFS of 6 months compared to 3 months (p = 0.048). Absence of metastasis and prior asbestos exposure in an endemic region were linked to better immunotherapy outcomes. Conclusion: Immunotherapy shows increased efficacy in later treatment lines for pleural mesothelioma, especially for patients without metastases or with prior endemic asbestos exposure. Tailored therapeutic strategies should be further explored in prospective studies.