Gabriela Raycheva

Dr. Gabriela Raycheva

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

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

Representative Publications

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12 September 2025 in Life
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Journal Article
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Nikolay DimovNikolay Dimov
Nikolay Dimov
AYAntonia Hristova Yaneva
Antonia Hristova Yaneva
EVEvelina Valcheva
Evelina Valcheva
GRGabriela Raycheva
Gabriela Raycheva
VPVeselin Popov
Veselin Popov
ZGZhanet Grudeva-Popova
Zhanet Grudeva-Popova
Nephrotoxicity is a common complication during antineoplastic therapy, particularly when platinum-based medications are used. Early detection of this condition is crucial for improving risk stratification and management, thereby enhancing decision-making in kidney disease treatment. However, traditional biomarkers for renal assessment lack sensitivity in identifying early or subclinical damage, underscoring the need for novel and more precise markers. This study aimed to investigate the effectiveness of urinary KIM-1, clusterin, nephrin, and serum cystatin C in detecting nephrotoxicity associated with platinum-based therapies. A total of 43 patients with different oncological diseases participated in the prospective study, divided into two groups based on the nephrotoxic potential of the administered drugs: patients treated with cisplatin (high-risk group for nephrotoxicity) and patients treated with oxaliplatin/carboplatin (low-to-moderate risk group for nephrotoxicity). The results showed that nephrotoxicity, determined as a decrease in eGFR of >10 mL/min/1.73 m2 at the sixth month after initiation of platinum-based therapy, occurred in 54.3% of cases, with 80% of these attributable to cisplatin-based therapy. Conventional renal biomarkers, such as the serum creatinine and urine albumin-creatinine ratio, have shown controversial results in the course of the study. In contrast, the patients treated with cisplatin, as well as those who developed nephrotoxicity, showed significant increases in the mean values of cystatin C (p < 0.001, respectively, p < 0.001), urinary KIM-1 (p = 0.005, respectively, p = 0.002), and urinary clusterin (p = 0.001, respectively, p = 0.001). Among the group with a low to moderate risk of nephrotoxicity including those treated with oxaliplatin/carboplatin, no statistically significant changes over time were observed in any of the biomarkers. These findings suggest that the aforementioned biomarkers can be used for the early detection of cisplatin-induced eGFR decline.

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Petar AntonovPetar Antonov
Petar Antonov
GRGabriela Raycheva
Gabriela Raycheva
Denis EshrefovDenis Eshrefov
Denis Eshrefov
ABAngel Belov
Angel Belov
PUPetar Angelov Uchikov
Petar Angelov Uchikov
PPPlamen Penchev
Plamen Penchev
Bladder cancer is a molecularly heterogeneous malignancy in which biomarker-driven therapies increasingly shape clinical management. Fibroblast growth factor receptor 3 (FGFR3) alterations and nectin-4 expression are key therapeutic targets, yet their integrated biological and clinical relevance remains unclear. A systematic search of PubMed, Scopus, and Cochrane Central was conducted from database inception to 22 February 2026 (PROSPERO: CRD420261309413). Studies reporting the prevalence of FGFR3 alterations and/or nectin-4 expression in bladder cancer were included. Proportions were pooled using a random-effects model with restricted maximum likelihood and Freeman–Tukey transformation. Heterogeneity was assessed with I2 and Cochran’s Q. Fourteen studies (three randomized and 11 observational), including 3955 patients (mean age: 67.34 years), were analyzed. The pooled prevalence of FGFR3 alterations was 52% (95% CI: 23.33–80.12; I2 = 99%), while that of nectin-4 expression was 78% (95% CI: 64.23–89.81; I2 = 91%). FGFR3 prevalence varied significantly by disease stage, study design, and region, with higher rates in advanced/metastatic disease and randomized trials (p < 0.05). Nectin-4 expression was generally high across included studies, although interpretation was limited by the small number of studies and assay variability. Sensitivity analyses showed the stability of estimates; however, interpretation is limited by substantial heterogeneity. The observed prevalence estimates are strongly influenced by study design, biomarker selection, and assay variability, limiting their interpretation as true biological prevalence. These results should, therefore, be interpreted cautiously and viewed as descriptive rather than definitive estimates. Separate analyses of biomarker-enriched trials and unselected cohorts are necessary to obtain clinically meaningful estimates.

29 October 2024 in Proceedings of the Bulgarian Academy of Sciences
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Journal Article
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Petar AntonovPetar Antonov
Petar Antonov
PKPlamen Krastev
Plamen Krastev
GRGabriela Raycheva
Gabriela Raycheva
AIAtanas Ivanov
Atanas Ivanov
VPVeselin Popov
Veselin Popov
ATAleksander Timev
Aleksander Timev
The aim of this study was to evaluate the efficacy of real-time shear wave elastography (SWE) in prostate cancer diagnosis in patients with elevated prostate-specific antigen values and abnormal results on digital rectal examination. This study included 74 patients (mean age 68.3 years) with suspected prostate cancer – prostate-specific antigen>4 ng/mL and abnormal digital rectal examination. All patients scheduled for transrectal ultrasound biopsy of the prostate underwent standard transrectal ultrasonography and SWE. The reported sensitivity and specificity of SWE in the various studies varied widely, from 43–96% and 33–96%, respectively. This study showed that patients with elevated levels of prostate-specific antigen, abnormal digital rectal examination, and negative SWE may not require a biopsy which could significantly reduce the number of biopsies performed.