ONUR ALKAN

Dr. ONUR ALKAN

Department of Medical Oncology, Medeniyet Üniversitesi Göztepe Eğitim ve Araştırma Hastanesi, Istanbul, İstanbul, Turkey (Türkiye)
orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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15 October 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
ZBZELİHA BİRSİN
ZELİHA BİRSİN
İNİsmail Nazli
İsmail Nazli
ONUR ALKANONUR ALKAN
ONUR ALKAN
HBHülya Odabaşı bükün
Hülya Odabaşı bükün
MGMurat Günaltılı
Murat Günaltılı
ÖAÖzkan Alan
Özkan Alan
Background: Pathological complete response (pCR) following neoadjuvant therapy (NAT) is a key surrogate marker for long-term outcomes in HER2-positive breast cancer. Identifying clinical and biological predictors of pCR, including systemic inflammatory and nutritional markers such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), neutrophil-to-albumin ratio (NAR), C-reactive protein-to-albumin ratio (CAR), systemic immune-inflammation index (SII), and prognostic nutritional index (PNI), may help refine treatment strategies and improve patient outcomes. Methods: We retrospectively analyzed 174 patients with stage II–III HER2-positive breast cancer who received neoadjuvant anti-HER2-based regimens at multiple centers between 2010 and 2025. Demographic, clinicopathological, and laboratory data were collected, and inflammatory and nutritional indices (NLR, PLR, LMR, NAR, CAR, SII, PNI) were calculated. Predictors of pCR were evaluated using univariate and multivariate logistic regression analyses. Results: Overall, 49% of patients achieved pCR. In multivariate analysis, independent predictors of pCR were hormone receptor negativity, smaller tumor size, HER2 IHC 3+ expression, dual HER2 blockade, and a higher prognostic nutritional index (PNI ≥ 55). In contrast, systemic inflammatory indices such as NLR, PLR, LMR, NAR, CAR, and SII were not significantly associated with pCR. Conclusions: This multicenter real-world study demonstrates that conventional inflammatory markers have limited predictive value, whereas the PNI emerges as a simple and practical biomarker reflecting nutritional and immune status. Integrating PNI with clinicopathological factors may enhance risk stratification and help guide individualized neoadjuvant treatment strategies in HER2-positive breast cancer.

18 November 2021 in Jundishapur Journal of Microbiology
Verified
Journal Article
Open access
PDF file
DODidem Ozgür
Didem Ozgür
MKMurat Karamese
Murat Karamese
AMAlpay Medetalibeyoglu
Alpay Medetalibeyoglu
ONUR ALKANONUR ALKAN
ONUR ALKAN
NSNaci Senkal
Naci Senkal
ETEdiz Tutuncu
Ediz Tutuncu
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may trigger a cytokine storm, which is characterized by uncontrolled overproduction of proinflammatory cytokines. Objectives: We aimed to investigate the association between circulating levels of inflammatory cytokines and severity of coronavirus disease 2019 (COVID-19). Methods: This cross-sectional study included 46 severe and 32 mildly symptomatic COVID-19 patients. The serum levels of cytokines and chemokines were determined using the Bio-Plex ProTM Human Cytokine Screening Panel. Results: Out of a total of 78 patients with confirmed COVID-19, 54 (69.2%) were males, and 24 (30.8%) were females. The mean age was 43.1 ± 13.3 and 58.2 ± 15 in mild and severe patients, respectively. Severe patients were characterized by significant laboratory abnormalities, such as increased WBC (P = 0.002) and neutrophil counts (P = 0.001), higher levels of ALT (P = 0.03), AST (P = 0.002), LDH (P < 0.001), urea (P = 0.013), ferritin (P < 0.001), D-dimer (P = 0.042), CRP (P < 0.001), and decreased lymphocyte (P < 0.001) and platelet (P = 0.045) counts. The levels of IL-6, IL-8, IL-13, TNF-α, IFN-γ, MIP-1β, and MCP-1 increased in the severe group compared to the mild group. However, significant differences were observed only for IL-6 (P < 0.001) and IL-8 (P < 0.001) levels. Conclusions: Serum IL-6 and IL-8 levels can be used as potential prognostic biomarkers of disease severity in COVID-19 patients.

5 September 2025 in Medicina
Verified
Journal Article
Open access
PDF file
ZBZELİHA BİRSİN
ZELİHA BİRSİN
HBHülya Odabaşı bükün
Hülya Odabaşı bükün
İNİsmail Nazli
İsmail Nazli
ONUR ALKANONUR ALKAN
ONUR ALKAN
MGMurat Günaltılı
Murat Günaltılı
ÖAÖzkan Alan
Özkan Alan
Background and Objectives: The prognostic significance of body mass index (BMI) in metastatic HER2-positive breast cancer (BC) remains unclear, with previous studies yielding conflicting results. This multicenter real-world study aimed to investigate the prognostic role of BMI in this patient population. Materials and Methods: A total of 169 female patients with metastatic HER2-positive BC who received trastuzumab-based treatment between 2010 and 2024 were included. Patients were categorized by BMI (<30 kg/m2 vs. ≥30 kg/m2). The primary endpoints were overall survival (OS) and progression-free survival (PFS). Kaplan–Meier and Cox regression analyses were performed overall and in subgroups stratified by hormone receptor (HR) status. Results: In the overall cohort, a BMI ≥ 30 was not significantly associated with OS or PFS. However, in the HR-positive/HER2-positive subgroup, BMI ≥ 30 kg/m2 was linked to significantly shorter OS (p = 0.024) and PFS (p = 0.047) by Kaplan–Meier analysis. However, these associations did not remain statistically significant in multivariate analyses. No significant BMI-related differences were observed in the HR-negative subgroup. Other independent negative prognostic factors included recurrent disease, the presence of brain metastases, and a high Ki-67 index. Conclusions: BMI was not identified as an independent prognostic factor in the overall population. However, among HR-positive/HER2-positive patients, obesity was associated with poorer survival in univariate analysis, but this was not confirmed in multivariate analysis. These findings underscore the need for prospective studies to clarify the prognostic role of adiposity, considering biological subtypes.

14 August 2026 in İstanbul Tıp Fakültesi Dergisi
Verified
Journal Article
Closed access
FAFATİH ATALAH
FATİH ATALAH
AKAkgun Karakok
Akgun Karakok
AAAYDIN ACARBAY
AYDIN ACARBAY
İNİsmail Nazli
İsmail Nazli
ONUR ALKANONUR ALKAN
ONUR ALKAN
MGMahmut Gumus
Mahmut Gumus
Objective: Metastatic urothelial carcinoma (mUC) demonstrates substantial clinical heterogeneity, and outcomes may vary despite similar treatment approaches. The hemoglobin, albumin, lymphocyte, and platelet (HALP) score has emerged as a potential prognostic biomarker reflecting nutritional, inflammatory, and immune status. This study evaluated the prognostic significance of HALP in patients with mUC treated with first-line platinum-based chemotherapy.Materials and Methods: We retrospectively evaluated patients with metastatic or unresectable urothelial carcinoma who received first-line platinum-based chemotherapy at a single center between january 2015 and december 2023. HALP scores were calculated using baseline laboratory parameters obtained before treatment initiation. Patients were stratified according to the median HALP value. Overall survival (OS) was the primary endpoint, and progression-free survival (PFS) was the secondary end point. Survival analyses were performed using the Kaplan – Meier and Cox regression methods.Results: A total of 118 patients were included. The median HALP value was 24; 64 patients were classified as low HALP and 54 as high HALP. Patients with low HALP had significantly poorer outcomes. Median PFS was 4.90 months in the low HALP group and 7.67 months in the high HALP group. Median OS was 5.82 and 20.33 months, respectively (p<0.001). In multivariable analysis, low HALP and age ≥ 65 years remained independently associated with worse OS.Conclusion: Low HALP score was associated with worse survival outcomes in patients with mUC receiving first-line platinum-based chemotherapy. As an easily obtainable laboratory-based index, HALP may provide additional prognostic information beyond conventional clinical factors.

1 June 2026 in Clinical Genitourinary Cancer
Verified
Journal Article
Closed access
CKCevat İlTeriş Kıkılı
Cevat İlTeriş Kıkılı
MAMurat Araz
Murat Araz
YÜYüksel Ürün
Yüksel Ürün
MBMert Başaran
Mert Başaran
NŞNur Şener
Nur Şener
DTDeniz Tural
Deniz Tural

1 January 2025 in Eurasian Journal of Medical Advances
Verified
Journal Article
Open access
PDF file
ONUR ALKANONUR ALKAN
ONUR ALKAN
NSNaci Senkal
Naci Senkal
AMAlpay Medetalibeyoglu
Alpay Medetalibeyoglu
MKMurat Köse
Murat Köse
The Eurasian Journal of Medical Advances (EJMA) is an open access, double-blind peer-reviewed medical journal publishing qualified research across all medical investigations. The journal is published quarterly in March, June, September and December. Objectives: Dysregulated inflammation drives severe COVID-19. Cytokine profiling has been proposed for risk stratifica-tion. Its value over conventional markers is unclear. We comp...