Okan Oktar

Dr. Okan Oktar

orcid

Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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1 January 2024 in Journal of Gynecologic Oncology
Verified
Journal Article
Open access
PDF file
OOOkan Oktar
Okan Oktar
VKVakkas Korkmaz
Vakkas Korkmaz
ATAlp Tokalıoğlu
Alp Tokalıoğlu
ÇÖÇağatayhan Öztürk
Çağatayhan Öztürk
ÖEÖzgür Erdoğan
Özgür Erdoğan
TTTaner Turan
Taner Turan
Oktar O, et al. J Gynecol Oncol. 2023 Dec;35:e39. https://doi.org/10.3802/jgo.2024.35.e39

23 February 2023 in Asia-Pacific Journal of Clinical Oncology
Verified
Journal Article
Closed access
DYDilek Yüksel
Dilek Yüksel
OAOkan Aytekin
Okan Aytekin
OOOkan Oktar
Okan Oktar
SASevgi Ayhan
Sevgi Ayhan
YUYeşim Özkaya Uçar
Yeşim Özkaya Uçar
TTTaner Turan
Taner Turan

2 February 2024 in Journal of Obstetrics and Gynaecology Research
Verified
Journal Article
Closed access
ATAbdurrahman Alp Tokalioglu
Abdurrahman Alp Tokalioglu
OOOkan Oktar
Okan Oktar
MŞMustafa Şahin
Mustafa Şahin
COCagatayhan Ozturk
Cagatayhan Ozturk
OEOzgur Erdogan
Ozgur Erdogan
TTTaner Turan
Taner Turan

12 December 2022 in Journal of Obstetrics and Gynaecology
Verified
Journal Article
Open access
MÜMehmet Ünsal
Mehmet Ünsal
CKCigdem Kilic
Cigdem Kilic
CÇCaner Çakır
Caner Çakır
FKFatih Kilic
Fatih Kilic
BEBurak Ersak
Burak Ersak
TTTaner Turan
Taner Turan
The aim of this study was to evaluate the prognostic factors for and determine the effect of neoadjuvant chemotherapy (NACT) on oncologic outcome in stage IVB pure serous endometrial carcinoma patients who received taxane and platinum. Forty-two patients with 2009 International Federation of Gynecology and Obstetrics (FIGO) stage IVB uterine serous carcinoma were enrolled from six gynecologic oncology centers and a study group was created. The study group had a 2-year disease-free survival (DFS) of 32% and 2-year disease-specific survival (DSS) of 73%. On univariate analysis; lymphadenectomy (not performed vs. performed), paraaortic lymph node metastasis (positive vs. negative) and number of metastatic lymph node count (≤5 vs. >5) were found to have statistical significance for DFS (p < 0.001, p = 0.026 and p = 0.044, respectively). Adnexal metastasis (positive vs. negative) and type of cytoreductive surgery (maximal vs. optimal and suboptimal) had statistical significance for DSS (p = 0.041 and p = 0.015, respectively). Receiving NACT did not affect DFS and DSS in stage IVB uterine serous carcinoma patients. As our sample size was small, precise conclusions could not be made for suggesting the use of NACT in advanced stage uterine serous carcinoma. For more accurate results, more randomized controlled studies are needed in this patient group.IMPACT STATEMENTWhat is already known on this subject? Endometrial carcinoma is the most common type of gynecologic tract malignancies and usually it is diagnosed at early stages. Although the favorable prognosis, uterine serous carcinoma (USC), one of the rarest subtypes, has a poorer prognosis when compared to other histological subtypes. USC has a propensity to spread beyond pelvis. Due to this aggressive behavior, surgical intervention could not be feasible in advanced stage disease.What do the results of this study add? Our study evaluated the prognostic factors that affect survival in advanced stage USC patients. Also we investigated that neoadjuvant chemotherapy (NACT) could improve oncologic outcomes. Performing lymphadenectomy, presence of paraaortic lymph node and adnexal metastasis, number of metastatic lymph nodes and type of cytoreductive surgery improved survival in advanced stage USC patients. However, NACT did not have a statistical significance as a predictor for disease-specific survival (DSS) and disease-free survival (DFS).What are the implications of these findings for clinical practice and/or further research? Maximal surgical effort should be performed in advanced stage USC according to our results. On the other hand, NACT had no impact on DSS and DFS rates. For this reason, we could not be able to suggest the routine use of NACT in advanced stage USC. But more randomized controlled trials are warranted for confirmation of our results.

16 January 2026 in Biomedicines
Verified
Journal Article
Open access
PDF file
GBgulay balkas
gulay balkas
SKSümeyye Nur Ünsal Keser
Sümeyye Nur Ünsal Keser
OOOkan Oktar
Okan Oktar
MAMustafa Can Akdogan
Mustafa Can Akdogan
MGMurat Gozukucuk
Murat Gozukucuk
YÜYusuf Üstün
Yusuf Üstün
Background: The aim of this study was to evaluate the diagnostic and prognostic performance of albumin-based inflammatory–nutritional indices in hyperemesis gravidarum (HG) and to determine their associations with disease severity and risk of re-hospitalization. Methods: This retrospective case–control study included 246 women with HG and 246 gestational-age-matched healthy pregnant controls at 6–16 weeks of gestation. Disease severity was classified as mild, moderate, or severe using the Pregnancy-Unique Quantification of Emesis (24 h scale) (PUQE-24) score. A comprehensive panel of albumin-based inflammatory indices—including C-reactive protein-to-albumin ratio (CAR), fibrinogen-to-albumin ratio (FAR), neutrophil-to-albumin ratio (NAR), leukocyte-to-albumin ratio (LAR), neutrophil percentage-to-albumin ratio (NPAR), monocyte-to-albumin ratio (MAR), hemoglobin–albumin–lymphocyte–platelet (HALP) score, modified HALP (m-HALP) score, prognostic nutritional index (PNI) score, systemic immune-inflammation index-to-albumin (SII/Alb), and systemic inflammatory response index-to-albumin (SIRI/Alb)—was calculated from routine complete blood count and serum biochemistry results obtained at diagnosis. Receiver operating characteristic analysis, along with univariate and multivariate logistic regression models, was performed to evaluate diagnostic performance and identify predictors of severe HG and re-hospitalization. Results: Albumin-based indices exhibited severity-associated alterations, with an overall trend toward worsening immuno-nutritional status across increasing HG severity. Among these, m-HALP score demonstrated the strongest inverse correlations with PUQE-24 score, ketonuria grade, length of hospital stay, and re-hospitalization risk (r = −0.74 to −0.52; all p < 0.001) and achieved the highest discriminative accuracy for both severe HG (AUC 0.864, 95% CI 0.836–0.892, p < 0.001) and re-hospitalization (AUC 0.722, 95% CI 0.675–0.766, p < 0.001). In multivariable analysis, higher HALP, m-HALP, and PNI were independently associated with a lower likelihood of severe HG. For re-hospitalization, higher m-HALP and HALP were independently associated with a lower risk, whereas higher NPAR, higher ketonuria grade, and higher PUQE-24 score were independently associated with an increased risk of re-hospitalization. Conclusions: Albumin-based indices, particularly m-HALP, demonstrated robust diagnostic and prognostic performance in HG compared with conventional biomarkers. These readily available, cost-neutral composite biomarkers enable objective severity stratification and accurate identification of patients at elevated risk of recurrent hospitalization, offering immediate potential to guide personalized, evidence-based clinical management.

30 October 2025 in Diagnostics
Verified
Journal Article
Open access
PDF file
YUYeşim Özkaya Uçar
Yeşim Özkaya Uçar
OAOkan Aytekin
Okan Aytekin
NYNecim Yalcin
Necim Yalcin
OOOkan Oktar
Okan Oktar
HYHande Esra Koca Yıldırım
Hande Esra Koca Yıldırım
TTTolga Tasci
Tolga Tasci
Background: To identify prognostic factors related to survival in patients with early-stage cervical cancer treated with radical surgery in six high-volume gynecologic oncology centers in Turkey. Methods: This retrospective analysis examined a cohort of 612 patients diagnosed with cervical cancer who underwent type II/III radical hysterectomy and pelvic lymphadenectomy, with or without para-aortic lymphadenectomy at six gynecologic oncology centers. A total of 537 patients between 1993 and 2023 were included. According to the 2009 FIGO staging system, 411 patients (76.5%) were stage IB1, 76 (14.2%) were stage IB2, 40 (4.7%) were stage IIA1, and 10 (1.9%) were stage IIA2. Patients underwent either type II or type III radical hysterectomy with pelvic lymphadenectomy, with para-aortic lymphadenectomy performed in 93.1% of cases. Among the 537 patients, 258 (48%) underwent type II radical hysterectomy and 279 (52%) underwent type III. Univariate and multivariate analyses of 5-year overall survival (OS) and 5-year disease-free survival (DFS) were performed. Results: In the entire cohort, 258 (48%) patients underwent radical surgery alone, while 279 (52%) patients underwent radical surgery followed by adjuvant therapy. The 5-year DFS and 5-year OS rates were 85.3% and 98.4%, respectively. In the multivariate logistic analysis, lymph node metastasis was identified as an independent prognostic factor for DFS and OS. Conclusions: Lymph node metastasis was the most important prognostic factor for survival in this large multicenter Turkish cohort. These findings highlight the prognostic value of nodal status, stromal invasion, margin status, and LVSI, while underscoring the importance of tailored adjuvant treatment strategies.